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Full text of "The Nautilus"

JANUARY 30, 1985 



THE 



NAUTILUS 



ISSN 0028-1344 



Vol. 99 



No. 1 




A quarterly 

devoted to 

malacology and 

the interests of 

conchologists 



Founded 1889 by Henry A. Pilsbry. Continued by H. Burrington Baker. 
Editor-in-Chief: R. Tucker Abbott 



EDITORIAL COMMITTEE 



CONSULTING EDITORS 



Dr. William K. Emerson 
Department of Living Invertebrates 
The American Museum of Natural History 
New York, NY 10024 

Dr. M. G. Harasewych 
363 Crescendo Way 
Silver Spring, MD 20901 

Dr. Aurele La Rocque 
Department of Geology 
The Ohio State University 
Columbus, OH 43210 

Dr. James H. McLean 
Los Angeles County Museum of Natural History 
900 Exposition Boulevard 
Los Angeles, CA 90007 

Dr. Arthur S. Merrill 
c/o Department of Mollusks 
Museum of Comparative Zoology 
Cambridge, MA 02138 

Dr. Donald R. Moore 
Division of Marine Geology 
School of Marine and Atmospheric Science 
10 Rickenbacker Causeway 
Miami, FL 33149 



Dr. Joseph Rosewater 
Division of Mollusks 
U.S. National Museum 
Washington, D.C. 20560 

Dr. G. Alan Solem 
Department of Invertebrates 
Field Museum of Natural History 
Chicago, IL 60605 

Dr. David H. Stansbery 
Museum of Zoology 
The Ohio State University 
Columbus, OH 43210 

Dr. Ruth D. Turner 
Department of Mollusks 
Museum of Comparative Zoology 
Cambridge, MA 02138 

Dr. Gilbert L. Voss 
Division of Biology 

School of Marine and Atmospheric Science 
10 Rickenbacker Causeway 
Miami, FL 33149 



EDITOR-IN-CHIEF 

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American Malacologists, Inc. 
Box 2255, Melbourne, FL 32902-2255 

Mrs. Cecelia W. Abbott 
Business and Subscription Manager 
P.O. Box 2255 
Melbourne, FL 32902-2255 



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and other post offices 



The Nautilus (USPS 374-980) 
ISSN 0028-1344 

A quarterly magazine devoted to malacology. 
Copyright c 1985 by American Malacologists, Inc. 

OFFICE OF PUBLICATION 

American Malacologists, Inc. (United Parcel Address: 

2208 South Colonial Drive, Melbourne, FL 32901) 

Mail: Box 2255, Melbourne, FL 32902-2255 

POSTMASTER: Send address changes to above. 

Subscription Price: $15.00 (see inside back cover) 

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THE 

NAUTILUS 

Volume 99, number 1 — January 30, 1985 

ISSN 0028-1344 



CONTENTS 

Richard H. Bailey 

Human Modification of Molluscan Habitats in Little Creek Estuary, Virginia. 

Mark E. Gordon 

Mollusca of Frog Bayou, Arkansas 



Anthony D'Attilio and Barbara W. Myers 

A New Species of Pygmaepterys Vokes from the Western Pacific 

(Gastropoda: Muricidae) 9 

William K. Emerson 

Murex hamatus Hinds, 1844, a Living West American Species Assigned to 

the Neogene Paciphile Genus, Pterorytis Conrad (Gastropoda: Muricidae) 14 

Clement L. Counts, III 

Corbicula Jluminea (Bivalvia: Corbiculidae) in the State of Washington 

in 1937, and in Utah in 1978 18 

Raymond W. Neck 

Tropical Veronicellid, Laevicaulis alte (Ferussac), Established in Southern Texas 19 

L. A. J. Al-Hassan and Z. I. Al-Hasani 

New Records of Marine Mollusca from Khor Abdullah, Iraq 20 

Paul E. Fell and John H. Williams 

Distribution of the Snail, Melampus bidentatus. and the Mussel, Geukensia demissa, 

Along the Pataguanset Estuary (Connecticut) in Relation to Salinity and 

Other Tidal Marsh Invertebrates 21 

William K. Emerson 

Two New Species of Lyria from the Western Atlantic (Gastropoda: Volutidae) 28 

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1985 AMU Meeting 
The American Malacological Union will hold 
its annual meeting on the campus of the Univer- 
sity of Rhode Island on July 29- August 3, 1985. 
Three symposia will be presented: one on mol- 
luscan egg capsules, organized by Jan Pechenik; 
a second on molluscan radulae, organized by 
Robert Bullock and Carole Hickman; and a third 
on ecology of freshwater molluscs, organized by 
Eileen Jokinen. There will also be contributed 
papers, a poster session, marine and freshwater 
field trips, workshops, an auction, exhibits and 
commercial sales of items of interest, and a New 
England clam bake. A program to honor junior 
malacologists will open the meeting. The Boston 
Malacological Club is planning special events in 
commemoration of its 75th anniversary. For 
further information please contact Dr. M. R. 
Carriker, College of Marine Studies, University 
of Delaware, Lewes, DE 19958. 



ii 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 



HUMAN MODIFICATION OF MOLLUSCAN HABITATS IN 
LITTLE CREEK ESTUARY, VIRGINIA 



Richard H. Bailey 

Department of Earth Sciences 

Northeastern University 
Boston, Massachusetts 02115 

ABSTRACT 

Mollusks of Little Creek estuary in southeastern Virginia may be grouped into 
five assemblages indicative of the following benthic habitats: 1) fringe and em- 
bayed Spartina marsh, 2) solid substrata (rock, pilings, shell), 3) intertidal muddy 
sand, 4) subtidal muddy sand, and 5) black organic mud. 

Human activities in the estuary such as dredging, stabilizing shorelines, land- 
filling, disposing of dredged spoil, and introducing foreign solid substrata have 
modified habitats and/or sediment character thus altering the distribution of 
molluscan assemblages. 



Human activities within and around shallow 
estuaries of the southeastern U.S. may have 
substantial effects on the distribution and com- 
position of bottom sediments. Substratum type 
exerts a strong control on benthic molluscan 
assemblages (Bird, 1970; Johnson, 1972). This 
paper correlates particular human activities 
with resultant changes in substratum and mol- 
luscan assemblage distribution in the western 
segment of Little Creek estuary. 

Little Creek is typical of the numerous small 
estuarine systems in heavily urbanized areas of 
southeastern Virginia (Fig. 1). It is somewhat 
unusual in that it was formerly a freshwater 
lake (Pretty Lake) impounded behind the ocean 




FIG. 1. Map of mouth of Chesapeake Bay showing location 
of Little Creek estuary and area enlarged in Figure 2. 



view barrier-bar and dune complex. When the 
bar and dunes were breached by dredging, 
Pretty Lake became a broad shallow estuary. 
East of the bridge where U.S. route 60 crosses 
Little Creek, commercial development, mainly 
marinas, and the U.S. Naval Amphibious Base 
dominate the shoreline. West of the U.S. 60 
bridge the original basin configuration has been 
less modified and the shoreline largely devoted 
to residential development. The western branch 
of Little Creek has about 21 km of shoreline of 
which about 26 percent (5.3 km) is narrow 
muddy beach, 51 percent (10.9 km) is fringe 
marsh, 18 percent (3.7 km) is embayed marsh, 
and 5 percent (1.0 km) is permanently stabilized 
by bulkheads and rip-rap (Owen and others, 
1976). The preceding figures include a small 
amount of shoreline east of the bridge. Water 
depths over most of the western segment of Lit- 
tle Creek range from 0.5 to 1.5 m (MLW). Max- 
imum depths of 1.7 to 2.5 m (MLW) were meas- 
ured in channels under the bridge and to the 
north of the sand shoal near the bridge (Fig. 2). 
The tidal range is approximately 0.8 m. Surface 
salinities measured in August 1976 and 1977 
ranged from 21 to 24°/ o with the lower values in 
the marsh channels at the western extremity 
and highest values in the vicinity of the bridge. 
Salinities at the mouth of the estuary near the 
Little Creek jetties in Chesapeake Bay ranged 
from 22 to 24°/ 00 . Current velocities are greatest 
at the constriction produced by the bridge. No 
current measurements were made, but large ac- 



THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 




FIG. 2. Subenvironments and sediment distribution in western branch of Little Creek. Numbers give locations of mollusk 
and sediment samples. 



Inter tidal Muddy 
Sand 



B. 



Subtidal Muddy 

Sand 
12 




SAND 




E *° 
E" E2 E E,. 

° d 



o E L. > 



CLAY 



GRAIN SIZE 



KH ; 3. Summary of sediment grain size analyses. Sand. silt. cla\ proportions of samples. A. Grain size distribution of 
sediments in subenvironments, B. 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 



tive ripples (2-4 cm high) and observable sand 
transport on the surface of the shoal (Fig. 2) in- 
dicate moderate tidal currents. Muddy and silty 
sediments are indicative low current velocities 
in most other areas. 

Sediment Distribution 

Sediment samples were obtained at 29 sta- 
tions (Fig. 2) and sediment types were mapped 
in the field at numerous locations along a longi- 
tudinal traverse from the bridge to station 10. 
The pattern of sediment distribution and sedi- 
ment character is summarized in Figures 2 and 
3. Coarsest sediment is found on the surface of 
the sand shoal (Fig. 2). Intertidal and subtidal 
muddy sands occur along the edges of the basin, 
as small bars, in channels, and in other areas 
where tidal currents are strong enough to pre- 
vent the accumulation of significant quantities 
of silt and clay. Black organic muds occur in 
marsh channels, dredged cuts off the main 
estuary, and in the central portion of the basin 
(Fig. 2). The black muds contain very large 
quantities of particulate organic detritus com- 
posed primarily ofSpartina alternijlora and ex- 
trabasinal macrodetritus such as leaf litter. The 
extensive area of embayed marsh at the far 
western end of Little Creek baffles currents 
during flood tides and traps considerable quan- 
tities of mud. 

Mollusk Distribution 

Mollusks were collected with a 10 cm diameter 
pipe dredge or with a shovel in localities where 
water depth was less than 1 m. Samples were 
washed in the field on a 1 mm sieve. All mollusks 
retained were identified and counted. Species 
distribution for samples and relative abundance 
is given in Fig. 4. Due to lack of uniform sample 
volumes precise quantitative comparisons can- 
not be made among stations. All species listed 
were found living, but at many locations most 
specimens collected were dead individuals. 

Species characteristic of major subenviron- 
ments are listed in Fig. 4. Note that some 
species, such as Ilyanassa obsoleta, achieve 
greatest abundance on intertidal and shallow 
subtidal muddy sand, but are common in other 
areas as well. The intertidal muddy sand, sub- 
tidal muddy sand, black organic mud sequence 
of subenvironments represents a substratum 



gradient from basin edge to basin center so it is 
not surprising to see strongly intergradational 
molluscan assemblages paralleling the gradient. 
Da vies (1972) described a suite of molluscan 
assemblages from the Rappahannock River 
estuary that are very similar to those given in 
Fig. 4. Substratum type is only one of several 
important controlling factors. Predation also 
exerts a strong influence on the distribution of 
mollusks. Many estuarine species escape intense 
predation by living high in the intertidal zone 
(Geukensia, Littorina, Crassostrea), burrowing 
deeply into sandy substrata (Mya, Tagelus) or in- 
habiting soupy muds that are difficult for preda- 
tors to search (Macoma, Mulinia). This flight 
from predation seems to be a strong secondary 
factor controlling the distribution of some 
estuarine mollusks. Shell damage due to preda- 
tion by Callinect.es, the blue crab, and possibly 
skates or rays was observed on some specimens 
if Mercenaria and Mulinia, 

Bivalves common in the upper part of the in- 
tertidal zone attach to solid substrata by means 
of a byssus (Geukensia, Ischadium) or by cemen- 
tation (Crassostrea). Littorina occurs in great 
abundance in the fringe marsh where it clings to 
Spartina. Large bivalves Mercenaria, Mya, and 
Tagelus are most abundant on sandy substrata 
capable of supporting their body mass. Rapid 
burrowers Tagelus and Mya are abundant in 
area of shifting substrata such as shallow sub- 
tidal bars and intertidal areas. Crepidula and 
Anomia are common in subtidal environments 
where rocks, shell, or foreign objects provide a 
solid substratum for permanent attachment. 
The black organic mud is a very soupy substra- 
tum that contains a very sparse bivalve fauna. 
Three species of Macoma and Mulinia lateralis 
have small enough whole animal mass to be sup- 
ported by the mud (Stanley, 1970). Macoma is a 
deposit feeder that can utilize the abundant 
organic detritus of the black mud. 

Modified and Unmodified Estuary 

A cross-section of a composite unmodified 
shallow estuary is shown in Fig. 5A. This com- 
posite is based on relatively unmodified portions 
of Little Creek and on nearby estuaries that 
have undergone little modification. A typical 
profile includes a marginal fringing marsh with 
either muddy or sandy sediment depending on 



THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



Substratum 
Type 



species 



samples 





8 21 13 14 17 12 19 28 15 27 4 16 18 22 26 11 23 25 20 24 



Geukensia demissa 


R AJA 


R C 


C 






Littorina irrorata 


A 








Crassostrea virginica 


R A 


A A 


R 


R R 




Ischadium recurva 


A 








Tagelus plebius 


A A C 


A A C C 




Mya arenaria 


C A A 


A R 


R 


llyanassa obsoleta 


C A 


A R C A R 


A 




R R 


Gemma gemma 


R 


A A R R 


R 


Polinices duplicatus 




R 




R 




Crepidula convexa 




R A A C C 




A 




Anomia simplex 




R 




R 




Urosalpinx cinerea 


R 




Mercenaria mercenaria 


R R A 




Nassarius vibex 


R 




Anadara cf A. ovalis 


R 




Acteocina canahculata 


R 




Macoma balthica 




R C C C 


R 


C A 


Muhnia lateralis 




RACACCA A 


A 


A 


Macoma phenax 




R R R R 




A 


M. tenta 




R R R 


C 





A- abundant, C= common, R=rare 
FIG. 4. Distribution of molluscan species in subenvironments. Double lines isolate species most 
characteristic for substrata at top of diagram. 



local current energy. Subtidal margins are 
usually muddy sand with a silt and clay content 
determined by tidal current and wave activity. 
Small islands are produced where intertidal bars 
are stabilized by Spartina. The sandy intertidal 
zone grades into muddy sand of the shallow sub- 
tidal environment which, in turn grades into 
black organic mud near the center of the basin. 



Black mud or muddy sand is also the typical 
bottom sediment in the tidal channels that pene- 
trate embayed marsh. In a natural estuary of 
the southeastern U.S. virtually the only solid 
substratum available is shell or wood fragments. 
The following types of physical modification 
by man have altered the substratum and mollus- 
can distribution in Little Creek: 



Type of Change or Structure 

1. Shoreline stabilization 
and landfill 
(bulkheads and rip- rap) 

2. Dredging new marsh 
channels into embayed 
marsh and basin margin 

3. Bridge across estuary 



4. Refuse Disposal 

5. Dredge spoil disposal 



Affect on Subenvironment or Substratum 

Reduces basin area 

Eliminates fringing marsh habitat 

Introduces solid substrata (rock and pilings) 

Introduces sand, silt and clay (during construction) 

Increases area of black organic mud 

Increases organic content of muds in open estuary 

Alters basin form 

Increases velocity of tidal currents that distribute sand and scour 

deep channels 
Introduces solid substratum 
Slightly increases quantity of solid substrata 
Increases grain size of sediment 
Causes shoaling of bottom 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 



A) Estuary cross section {natural) 



Ltttonno 

Crossostreo 

Geukensia 




Channel deepened by 
tidal ecour 



B) Estuary cross section (urbanized) 

FIG. 5. Schematic estuary cross sections showing changes 
in molluscan habitats induced by man. Natural or undis- 
turbed estuary, A, urbanized estuary, B. 



Fig. 5B illustrates a composite cross-section of 
the natural estuary after urbanization. The 
basin has been reduced in area and much of the 
marsh habitat has been eliminated by "reclama- 
tion". This restricts the population size of the 
marsh fringe mollusks and affects the trophic 
dynamics and nutrient cycling in the system. 
Dredging or opening channels in embayed 
marsh allows tidal currents to remove coarser 
Spartina detritus and mats before it has 
thoroughly decayed or been modified by bac- 
teria (Odum and LaCruz, 1967). Excess organic 
detritus settles into muds of the quiet central 
regions of the estuary producing anoxic bottom 
conditions. This process occurs naturally, but it 
is exacerbated by man's activities in the marsh. 
Marsh areas serve as a buffer to the estuarine 
system in that they reduce runoff and trap fine 
sediment (Welsh and others, 1978). Removing 
marsh from the basin, while increasing surface 
runoff in adjacent watershed areas, allows large 
quantities of silt and clay to be introduced and to 
accumulate in regions of low tidal energy. The 
mud bottom in the mid-reaches of Little Creek, 
around station 20, is covered with a very fluid 
flocculent layer of silt and clay up to 0.5 m thick. 
Such soupy substratum is usually inhabitated 
only by very rare individuals of Macoma 
balthica. 

Due to the redistribution of sandy dredge spoil 



by tidal currents (Fig. 2) certain areas of Little 
Creek contain considerably more sand than 
would be expected in a natural estuary of com- 
parable size. A substantial sand shoal and exten- 
sive areas of intertidal and subtidal muddy sand 
have enlarged the habitat of molluscan species 
prefering a coarser substratum. This might be 
viewed as a benefit in that the commercially ex- 
ploitable species Mya armaria and Mercenaria 
mercenaria are more abundant on sandy bot- 
toms; however, unsatisfactory water quality 
hampers utilization of the shellfish resource 
(Owen and others, 1976). 

Almost all solid substrata that are permanent- 
ly exposed have been intensively colonized by 
mollusks. Crassostrea virginica is most abun- 
dant on introduced objects. There are no oyster 
"reefs" within Little Creek, but clumps of 
oysters established on foreign objects are 
dispersed over some intertidal and subtidal 
muddy sand flats. Crepidula convexa was found 
in great numbers on cans and other foreign 
metal substrata. Objects disposed of in the black 
mud provide support for molusks such as 
Crepidula that would not normally live in that 
subenvironment. 

Summary 

Human activities have significantly altered 
the distribution of mollusks in Little Creek by 
modifying basin configuration, hydrography, 
and substratum distribution. It appears that no 
molluscan habitat has been entirely eliminated, 
though all have been changed. The large area of 
Spartina marsh at the head of the creek is now 
protected by the Virginia Wetlands Act (Owen 
and others, 1976). Most dredging in the marsh 
predates this legislation. As the basin is now en- 
circled by urban development future areal con- 
striction is unlikely. In terms of the physical en- 
vironment, Little Creek estuary and its mollus- 
can community seems to be in a mature urban- 
ized condition. 

This study indicates the ease with which bot- 
tom types (substrata) may be characterized and 
mapped in a small estuary. The substratum dis- 
tribution map successfully delimits the habitats 
potentially available to molluscan assemblages 
even though an expected assemblage may not 
fully occupy areas of preferred substratum at 
the instant of sampling. Changes in bottom type 



THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



associated with human acitivities in and around 
the estuary can be monitored easily and quickly, 
and the ultimate effect on molluscan species or 
assemblages can be predicted. 

LITERATURE CITED 

Bird, S. O. 1970. Shallow • marine and estuarine benthic 
molluscan communities from area of Beaufort, North 
Carolina. Amer. Assoc. Petrol. Geol. Bull. 54:1651-1676. 

Christian, R. R. and R. L. Wetzel. 1978. Interactions be- 
tween substrate, microbes, and consumers of Spartina 
detritus in estuarines. p. 93-113. In: M. L. Wiley (ed.) 
Estuarine Interactions. Academic Press, N.Y. 603 p. 

Davis, T. T. 1972. Effects on environmental gradients in the 
Rappahannock River estuary and the molluscan fauna. 
p. 263-290. In: B. W. Nelson (ed.) Environmental Frame- 
work of Coastal Plain Estuaries. Geol. Soc. Amer. Memoir 
133. 619 p. 



Johnson, R. E. lDTli. Conceptual models of benthic marine 
communities, p. 148-159. In: T. J. M. Scopf (ed.) Models 
in Paleobiology. Freeman, Cooper, and Co., San Fran- 
cisco. 250 p. 

Odum, E. P. and A. A. de La Cruz. 1967. Particulate organic 
detritus in a Georgia salt marsh - estuarine ecosystem. 
p. 383-388. In: G. H. Lauff (ed.) Estuaries. AAAS Publ. 
83. Wash., D.C. 757 p. 

Owen, D. W., L. M. Rogers and M. H. Peoples. 1976. Shore- 
line situation report cities of Chesapeake, Norfolk and 
Portsmouth. Va. Inst. Mar. Sci. Spec. Report 136. 87 p. 

Stanley, S. M. 1970. Relation of shell form to life habits of 
the bivalvia (Mollusca). Geol. Soc. Amer. Meinuir 125. 
296 p. 

Welsh, B. L., J. P. Herring and L. M. Read. 1978. The ef- 
fects of reduced wetlands and storage basins on the stabil- 
ity of a small Connecticut estuary, p. 381-401. In: M. L. 
Wiley (ed.) Estuarine Interactions. Academic Press, N.Y. 
603 p. 



MOLLUSCA OF FROG BAYOU, ARKANSAS 



Mark E. Gordon 

Department of Zoology 

University of Arkansas 

Fayetteville, Arkansas 72701 

ABSTRACT 
Very few records ofmollnsks within the Arkansas River basin exist for Arkan- 
sas. Twenty-five species were collected from, Frog Bayou, a small tributary of the 
Arkansas River in western Arkansas. The fauna is dominated by Interior Basin 
species with minimal influence from Interior Highlands endemics. However, 
southern, affinities are represented. 



The majority of malacological investigations 
within the Arkansas River drainage have been 
conducted in Oklahoma, Kansas, and Colorado 
(e.g. Isely, 1925; Murray and Leonard, 1962; 
Wu, 1978), while the lower portions of the basin 
remain largely unexamined. Within Arkansas, 
only a few incidental references to the occur- 
rence of mollusks in this sytem have been pub- 
lished (e.g. Kraemer, 1976; Gordon, et al. 1980). 
The distribution of mollusks in Frog Bayou, a 
small Interior Highlands tributary of the Arkan- 
sas River in western Arkansas, is presented. 



Materials and Methods 

Frog Bayou drains portions of the extreme 
southern Ozark Plateaus and the northern slope 
of the Arkansas Valley (Ouachita Mountains 
province). The permanent flowing channel 
crosses the eastern half of Crawford County, 
Arkansas (Atoka sandstone). Substrates in 
upper Frog Bayou are quite rocky with large 
areas of exposed bedrock and rather high gra- 
dients. Middle portions are impounded by Lake 
Shepherd Springs (304 ha.) and Lake Fort 
Smith (212 ha.), while the mouth in inundated by 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 



Ozark Lake of the McClellan-Kerr Arkansas 
River Navigation System. Lower Frog Bayou 
may be quite sluggish and include mud and sand 
substrate (Arkansas River aluvium). Collections 
were made by hand at 15 access areas along the 
permanently flowing portion (Figure 1). Addi- 
tional records were obtained for Lake Fort 
Smith from ichthyoparasite slides prepared by 
Cloutman (1974). Voucher specimens are 
deposited at the University of Colorado 
Museum. 

Results 

Twenty-five species of mollusks were col- 
lected (Table 1). This included seven gastropods, 
17 unionacean mussels, and Corbicula fluminea 
(Miiller). The fauna above the reservoirs con- 




Arkansas 

Riv«r 



FIG. 1. Location of sampling stations on Frog Bayou, 
Crawford County, Arkansas. Open circles represent stations 
at which no mollusks were found. 



sisted only of pulmonates, primarily Physella 
gyrina (Say). Glochidial preparations by Clout- 
man (1974) indicate that Quadrula pustulosa 
(Lea) and Anodonta grandis Say occur in Lake 
Fort Smith. No other mollusks were collected 
from either reservoir. Lake Fort Smith is an im- 
pediment to water flow which may often be in- 
termittent for several kilomenters downstream 
during late summer and early autumn. This area 
yielded only relicts of Proptera purpurata 
(Lamarck) and Lam.psilis hydiana (Lea). The 
majority of species were found from Rudy down- 
stream to the vicinity of Kibler. No mollusks 
were observed near the mouth. 

Discussion 

The molluscan fauna of Frog Bayou is com- 
posed primarily of widespread Interior Basin 
species. The only Interior Highlands endemic, 
Elimia potosiensis (Lea), oddly was found at the 
lowest sampling sight, rather than in rockier, 
higher gradient areas upstream representing 
more typical habitats for this species. A rather 
obscure species, Menetus sampsoni ("Ancey" 
Sampson), seems to be associated with the In- 
terior Highlands but its distribution has not 
been clearly defined and may be more wide- 
spread (see Burch and Tottenham, 1980). Fer- 
rissia cf. arkansasensis Walker also appears to 
be associated with the Interior Highlands. This 
form was synonymized under F. rivularis (Say) 
by Basch (1963) but seems to be a distinct 
species and may be found sympatrically with the 
latter. I have only been able to locate F. arkan- 
sasensis from a limited area of the Interior 
Highlands. 

The unionacean component of Frog Bayou is 
strictly an Interior Basin fauna. There are no In- 
terior Highlands endemics present and most are 
very common, widely distributed species. The 
presence of Leptodea leptodon (Rafinesque) 
establishes this species within the Arkansas 
River basin and geographically unites southern 
records (e.g. Wheeler, 1918; Isely, 1925) with 
northern populations. It also suggests that 
Call's (1885: see Scammon, 1906; Murray and 
Leonard, 1962) record may have been valid for 
Kansas (Neosho River). Additionally, a southern 
affinity is represented by three species: Prop- 
tera purpurata, Lampsilis hydiana, and L. 
satura (Lea). Proptera purpurata and L. 



8 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



TABLE 1. Mollusca of Frog Bayou, Arkansas. (See Fig. 1 for station localities. 



Station: 


1 2 


3 4 5 6 


7 


a 


• 


10 


Class Gastropoda 














Family Pleuroceridae 














Elijnia potosiensis (Lea) 












X 


Family Lymnaeidae 














Fossaria obrussa (Say) 


X 












Family Physidae 














Physella gyrina (Say) 


X X 










X 


Family Planorbidae 














Menetus sampsoni ("Ancey" Sampson) 


X 












Helisoma anceps (Menke) 


X 












Family Ancylidae 














Ferrissia rivularis (Say) 


X 












Ferrissia cf. arkansasensis Walker 


X 


X 




X 






Class Bivalvia 














Family Amblemidae 














Subfamily Ambleminae 














Fusconaia flava (Rafinesque) 




X X 


X 


X 




X 


Quadrula pustulosa (Lea) 




X 


X 


X 




X 


Tritoqonia verrucosa (Rafinesque) 




X X 


X 


X 




X 


Amblema plicata (Say) 












X 


Subfamily Lampsilinae 














Obliquaria reflexa Rafinesque 






X 




X 




Actinonaias ligamentina (Lamarck) 






X 


X 


X 


X 


Truncilla truncata Rafinesque 






X 




X 




Leptodea fragilis (Rafinesque) 












X 


Leptodea leptodon (Rafinesque) 






X 








Proptera purpurata (Lamarck) 




X 




X 


X 


X 


Lampsilis teres (Rafinesque) 






X 




X 


X 


Lampsilis hydiana (Lea) 




X 


X 


X 


X 


X 


Lampsilis satura (Lea) 




X 


X 




X 


X 


Family Unionidae 














Subfamily Anodontinae 














Anodonta grandis Say 




X 










Lasmiqona costata (Rafinesque) 






X 






X 


Alasmidonta marginata 1 (Say) 












X 


Subfamily Strophitinae 














Strophitus undulatus (Say) 








X 




X 


Family Corbiculidae 














Corbicula fluminea (MUller) 




X 


X 


X 




X 



Strophitini Gordon (1981) is elevated to subfamilial status. 



hydiana appear to replace P. alata (Say) and L. 
radiata siliquoidea (Barnes), respectively, in the 
south. Lampsilis satura is closely related to 
(and often confused with) L. ventricosa 
(Barnes), representing a southern clinal varia- 
tion probably fitting within the model presented 
by Cvancara (1963). While these three species 
are members of the Interior Basin fauna, they 
only range north to approximately 38°30' N. 
latitude and have colonized Gulf coastal systems 
east and west of the Mississippi River. Thus, the 
Arkansas River appears to have served as a cor- 
ridor through the Interior Highlands for disper- 
sal of both common Interior Basin species and a 
more restricted southern component. 

Acknowledgments 

This study was partially funded by a grant 
from the University of Arkansas Foundation, 
Inc. and was adapted from a thesis submitted in 



partial fulfillment of a M.S. degree, University 
of Arkansas. 



LITERATURE CITED 

Basch, P. F. 1963. A review of the recent freshwater limpet 
snails of North America. Bull. Mus. Comp. Zool. 129: 
399-461. 

Burch, J. B. and J. L. Tottenham. 1980. North American 
freshwater snails: species list, ranges and illustrations. 
Walkerana 1:81-215. 

Call, R. E. 1885. Contributions to a knowledge of the fresh- 
water Mollusca of Kansas, III: Fresh-water bivalves. 
Bull. Washburn Coll. Lab. Nat. Hist. 1:93-97. 

Cloutman, D. G. 1974. Parasite community structure of 
selected game fishes related to season and water quality 
in Lake Fort Smith, Arkansas. Unpublished M.S. thesis, 
University of Arkansas-Fayetteville. 124 pp. 

Cvancara, A. M. 1963. Clines in three species of Lampsilis 
(IVlecypnda: I'nionidae). Malacologia 1:215-226. 

Gordon. M. E. 1981. Recent Mollusca of Arkansas with 
annotations to systematics and zoogeography. Pror. Ark. 
Acad. Sci. 34(1 980): 58-62. 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 



Gordon, M. E., L. R. Kraemer and A. V. Brown. 1980. 
Unionacea of Arkansas: historical review, checklist, and 
observations on distributional patterns. Bull. Am. 
Malacol. Union 1979:31-37. 

Isely, F. B. 1925. The fresh-water mussel fauna of eastern 
Oklahoma. Proc. Okla. Acad. Sri. 4:43-118. 

Kraemer, L. R. 1976. An evaluation of the effects of dredg- 
ing within the Arkansas River Navigation System, vol. 
IV: the effects upon the benthic associations. Ark. Water 
Resources Res. Center Pub. 46:1-357. 



Murray, H. D. and A. B. Leonard. 1962. Handbook of 
unionid mussels in Kansas. Univ. Kans. Mus. Nat. Hist. 
Misc. Pub. 28:1-184. 

Scammon, R. E. 1906. The Unionidae of Kansas, part 1. 
Univ. Kans. Sri. Bull. 3:279-373. 

Wheeler, H. E. 1918. The Mollusca of Clark County, Arkan- 
sas. The Nautilus 31:109-125. 

Wu, S.-K. 1978. The Bivalvia of Colorado, part 1: the finger- 
nail and pill clams (Family Sphaeriidae). Nat. Hist. Invent. 
Colo. 2:1-39. 



A NEW SPECIES OF PYGMAEPTERYS VOKES 
FROM THE WESTERN PACIFIC (GASTROPODA: MURICIDAE) 



Anthony D'Attilio and Barbara W. Myers 

Department of Marine Invertebrates 

Natural History Museum 

P.O. Box 1390 

San Diego, California 92112 

ABSTRACT 
A new species q/Tygmaepterys, P. bellini, from off Okinawa and the Philippine 
Islands, is described. Comparison is made with P. funafutiensis (Hedley, 1899), 
and P. philclover (Houart, 1984), both western Pacific congeners. 



Vokes (1978) erected Pygmaepterys as a sub- 
genus of Pterynotus Swainson, 1833, describing 
this subgenus as small for a Pterynotus, with six 
winged varices, strong spiral cords and numer- 
ous axial lamellae; the aperture denticulate on 
the outer lip and "occasionally small denticles on 
the inner lip." She designated Pygmaepterys 
alfredensis (Bartsch, 1915) as the type species. 
P. alfredensis is a small six-mm specimen, very 
worn, with the early whorls and varices eroded. 
The shoulder is concave and the suture deeply 
impressed. There are 12 major cords on the 
body whorl. P. alfredensis is illustrated in Vokes 
(1978) pi. 7, figs, la, lb, 2a and 2b and in Vokes 
and D'Attilio (1980) pi. 2, figs, la and lb. The 
type locality is Port Alfred, South Africa. Ap- 
parently additional specimens have not been 
found of this species. Bartsch (1915) in his 
original description of P. alfredensis mentions 
no denticles on either the inner lip or the outer 
lip of the aperture. 

Vokes and D'Attilio (1980) described three 
new species of Pygmaepterys and assigned one 
other species to the genus, but expressed some 



doubts regarding the qualitative character of 
the inner lip denticles. 

As a result of the species studied for this 
paper we have concluded that although denticles 
in the outer lip are a good character of the 
genus, Pygmaepterys, the presence or absence 
of nodes or denticles on the inner lip or col- 
umella is inconsistent. 

The following abbreviations are used: 
SDNHM - San Diego Natural History Museum 
AMNH - American Museum of Natural 
History, New York. 

Family Muricidae Rafinesque, 1815 

Subfamily Muricopsinae 

Radwin and D'Attilio, 1971 

Genus Pygmaepterys Vokes, 1978 

Type species: Murex alfredensis Bartsch, 1915, 

by original designation. 

Pygmaepterys bellini new species 
Figs. 1-4, 9, 12 

Description: Shell small, fusiform; spire elon- 
gate with four convex post-nuclear whorls; 



10 THE NAl'TIU'S 



January 30, 1985 



Vol. 99(1) 




FIGS. 1 and 2. Pygmtieptcrys hellim D'Attilio and Myers. 
Dorsal (1) and apertural (2) views of holotype, SDNHM 
83065. Okinawa, Japan. 9.9 mm x 5.5 mm. 

FIGS. 3 and 4. Pygmaepterys bellini D'Attilio and Myers. 
Dorsal (3) and apertural (4) views of paratype SDNHM 
83067a. Philippine Islands. 12.0 mm x 5.5 mm. 



FIGS. 5 and 6. Pygmaepterys philcloveri (Houart, 1984). 

Dorsal (5) and apertural (6) views. SDNHM 83068. 13.7 

mm x 8.00 mm. 
FIGS. 7 and 8. PygiititeptrrysfinKifutiettsis (Hedley, 1899). 

Dorsal (7) and apertural (8) views of specimen from the 

Donald Pisor collection. 12.0 mm x 7.2 mm. 



suture impressed. Protoconch of one and one- 
half smooth convex whorls, white in color. Aper- 
ture narrowly ovate; anal sulcus broadly 
U-shaped; inner lip mostly appressed except 
very slightly erect anteriorly with one strong 
node on columella at entrance to the canal; en- 
tire columella stained dark-brown. Outer lip 
wavy, reflecting the external spiral cords with 
six strong nodelike denticles within. Siphonal 
canal open, tapered and recurved. Three distal 
portions of previous canals terminate on 
siphonal fasciole. Six axial varices per whorl ir- 
regularly descend relative to axis of shell. A few 
well-defined erect lamellae occur between the 
varices and a few regularly-spaced translucent 
lamellae crowd against the leading side of the 
varix. These lamellae undulate over the spiral 
sculpture giving a scabrous appearance to the 
shell. Eleven strong regularly-spaced spiral 
cords with equally wide interspaces occur on the 
body whorl; intermediate minor spiral cords oc- 



cur only on the varical flange. The color of shell 
varies from translucent white to white with one 
to three brown stripes on the body whorl. 

Type Material: Holotype SDNHM 83065 from 
Okinawa, Ryukyu Islands, Japan (Figs. 1, 2, 9, 
12). Paratype SDNHM 83066a and Paratype 
83066b from Okinawa. Paratype SDNHM 
83067a from the G. Everson collection from 
Philippine Islands (Figs. 3, 4). Paratype 
SDNHM 83067b from B. Myers collection from 
Philippine Islands. Paratype AMNH 213704 
from Okinawa. 

Type Locality: 52 meters depth off Okinawa, 
Ryukyu Islands, Japan. 

Dimensions (in mm): 





Length 


Width 


SDNHM 83065 


9.9 


5.5 


SDNHM 83066a 


10.2 


4.8 


SDNHM K30661, 


7.9 


4.9 


SDNHM 83067a 


12.0 


7.0 


SDNHM 83067b 


9.9 


5.5 


AMNH 213704 


8.0 


4.5 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 11 



Etymology: Named for Mr. Philip Bellin of 
Hawaii who first collected specimens off 
Okinawa, Japan. 

Discussion: Of the six specimens studied, 
three have immature lips with no nodes or denti- 
cles. Paratype 83066a has six denticles on the 
outer lip and three nodes on the anterior wall of 
the columella. Paratype 83066b has seven denti- 
cles on the outer lip and one node on the col- 
umella at the entrance to the siphonal canal. 

Comparison is made with P. funafutiensis 
(Hedley, 1899). See Table 1. The type specimen 
of P. funafutiensis is from Funafuti Atoll, Ellice 
Islands and is 9 mm in height. Specimens in the 
San Diego Natural History Museum, lot #71304, 
dredged from 183 m in Pokai Bay, Oahu, 
Hawaii, consist of four specimens, the larger of 
which is 9.8 mm x 6.2 mm and two fragments. 
Both the type specimen from Ellice Islands and 
the larger specimen from Hawaii are illustrated 
in Vokes and D'Attilio (1980), pi. 2, figs. 4, 5a 
and 5b. P. funafutiensis has a heavier coarser 



shell with six axial varices and five postnuclear 
whorls. There are five strong spiral cords on the 
body whorl with wide interspaces, each inter- 
space with five to seven incised lines. P. bellini 
has 11 regular, moderately strong cords with 
equal interspaces and intermediate cords only 
on the varical flange. Growth lamellae in P. 
funafutiensis are close-set and three to four 
times as numerous as in P. bellini. P. funafu- 
tiensis has five apertural denticles on the outer 
lip; the first and second denticles posteriorly are 
most prominent. P. bellini has six denticles of 
even strength. The columella of P. funafutiensis 
lacks any trace of the brown stain prominent in 
P. bellini. The color of P. funafutiensis is tan 
with a diffused brown band subsuturally and one 
at the base of the body whorl. A specimen of P. 
funafutiensis from the Philippine Islands in the 
collection of Donald Pisor of San Diego, Califor- 
nia, measures 12 mm x 7.2 mm (Figs. 7, 8, 11, 
14). This specimen does not differ in any essen- 
tial respect from those from Hawaii except that 



TABLE 1. Comparison of Pygmaepterys bellini new species, P. philcloveri Houart and P. funafutiensis (Hedley). 





P. bellini 


P. philcloveri 


P. funafutiensis 


Color: 


All white or white with brown 
bands and with brown stain on 
columella 


Rust brown with pale brown 
band; columella white, no 
brown stain 


Tan with brown band, columella 
white, no brown stain 


Shape: 


Fusiform, spire elongate 


Fusiform, spire moderately 
elongate 


Fusiform, spire moderately 
elongate 


Size 


To 12.0 mm x 7.0 mm 


To 13.7 mm x 8.0 mm 


To 12.0 mm x 7.2 mm 


Protoconch: 


White, 1V 2 blunt whorls 


Tan, 1% conical whorls 


Brown. IV2 low depressed 
whorls 


Postnuclear whorls: 


Four 


Five 


Five 


Varices: 


Six, irregularly descending 


Six, regularly descending 


Six, regularly descending 


Peristome: 


Simple ovate, inner lip 
appressed slightly erect 
anteriorly 


Irregularly ovate, inner lip 
erect, flattened posteriorly 


Simple ovate, inner lip mostly 
appressed 


Anal sulcus: 


Shallow and broad 


Moderately broad and deep 


Broad and deep 


Varical flange: 


Very weakly lamellose reflect- 
ing the numerous spiral cords 


Entirely scabrously lamellose 
reflecting the numerous spiral 
cords 


Five deep grooves, reflecting 
the five strong spiral cords 


Suture: 


Impressed 


Moderately impressed 


Moderately impressed 


Denticles: 


Six on outer lip, one on 
columella 


Six on outer lip, five on 
columella 


Five on outer lip, two on 
columella 


Growth lamellae: 


A few erect lamellae appressed 
over the spiral cords 


Numerous erect lamellae 
appressed over the spiral cords 


Very numerous lamellae 
appressed over entire shell 


Spiral cords: 


Eleven moderately strong 
cords terminating at end of 
siphonal canal 


Twelve major cords terminat- 
ing at tube-like portion of 
siphonal canal 


Five major cords followed by 
five minor cords terminating 
at end of siphonal canal 



12 THE NAUTILUS 



January 30, 1985 



Vol. 99 (1) 










FIG. 9. Detail drawing of protoconch of P. bellini. Holotype 

SDNHM 83065. 
FIG. 10. Detail drawing of protoconch of P. philcloveri. 

SDNHM 83068. 
FIG. 11. Detail drawing of protoconch of P. fmwfutiensis. 

Donald Pisor collection. 
FIG. 12. Detail drawing of aperture of P. bellini. Holotype 



SDNHM 83065. 
FIG. 13. Detail drawing of aperture of P. philcloveri. 

SDNHM 83068. 
FIG. 14. Detail drawing of aperture of P. junafutiensis. 

Donald Pisor collection. 
FIG. 15. Detail drawing of operculum of P. philcloveri. 

SDNHM 83068. 



nodes on the columella number two instead of 
three. 

A second new species of Pygmaepterys had 
been under study by us. A description of this 
species has recently been published by Houart 
(July, 1984). The description prepared by us 
follows: 

Pygmaepterys philcloveri (Houart, 1984) 

1984 Poirieria (Pazinotus) philcloveri Houart, 
Informations, series 12, nos. 2, 3, pp. 127-130. 
(off Samal Id., Davao, Mindanao Id. Philippines). 
Figs. 5, 6, 10, 13, 15 
Description: Shell strongly fusiform, spire 
moderately elongate, suture moderately im- 
pressed. Protoconch of one and three-fourths 
conical, convex smooth, pale brown whorls; five 
post nuclear whorls. Anal sulcus u-shaped and 
deep. Inner lip appressed posteriorly, strongly 
erect two- thirds distance from siphonal canal; 
five elongate denticles occur on lower portion of 
columella, the most anterior denticle situated 
directly above the entrance to siphonal canal. 
Outer lip erect, wavy, reflecting the external 
spiral sculpture with six denticles arranged as 
follows: two small denticles posteriorly followed 



by a very large denticle midway, two slightly 
smaller denticles below and a large bifid denticle 
above entrance to siphonal canal. Siphonal canal 
open, broad and tapering distally becoming 
recurved and tubelike. Three distal portions of 
previous canals terminate on siphonal fasciole. 
Seven axial varices on spire diagonally descend 
to the body whorl where the varices number 
only six. Varices blade-like continue above the 
shoulder and abut the suture. Entire surface of 
shell with very fine scabrous close-set axial 
growth lamellae. Spiral sculpture of 12 cords 
starting at shoulder; first five prominent and 
somewhat spinose at the varical margins with 
prominent open spines at the shoulder; inter- 
spaces wide; remaining seven cords narrower 
and more close-set with diminishing inter- 
spaces. Operculum typically Muricopsinae. 

Color: Rust-brown with a pale band starting at 
the shoulder and encompassing the first three 
cords. The rust-brown is much darker below the 
suture. The distal portion of the canal is gray- 
white and the aperture is white. Length of shell 
13 mm. 

Discussion: P. philcloveri in comparison with 
P. bellini has a slightly larger, more robust 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 13 



shell. See Table 1. The shell is distinguished 
most significantly in the apertural characters. 
The aperture of P. philcloveri is irregularly 
ovate and the inner lip strongly erect over most 
of its length. There is a deep anal sulcus in com- 
parison to the broad shallow sulcus of P. bellini. 
Although the number of denticles is the same, 
the arrangement and size differ in that P. bellini 
has six denticles of equal strength, while P. 
philcloveri has two small denticles posteriorly 
followed by a very large denticle midway on the 
outer lip with two smaller denticles following 
and one large bifid denticle above the entrance 
to the siphonal canal. P. bellini has six varices ir- 
regularly descending to the body whorl, while P. 
philcloveri has seven regularly descending axial 
varices on the spire reduced to six on the body 
whorl, the varix lacking is between the final 
varix and the preceding one. The entire surface 
of P. philcloveri consists of fine, strong, close- 
set scabrous lamellae in contrast to the few 
translucent erect lamellae of P. bellini. The 
overall brown stain on the columella of P. bellini 
is not found in P. philcloveri. P. bellini has a 
white shell with three brown bands and P. phil- 
cloveri has a rust brown shell with a pale brown 
band. 

P. funafutiensis (Hedley, 1899) differs from P. 
philcloveri in the protoconch which is depressed 
and not conical. The inner lip of P. funafutiensis 
is mostly appressed, not erect as in P. phil- 
cloveri and there are five denticles on the outer 
lip of more or less equal strength in contrast to 
the six denticles of unequal size and strength of 
P. philcloveri. The spiral sculpture of P. funafu- 
tiensis consists of five very strong major cords 
with five minor cords while P. philcloveri has 12 
strong major cords. The growth lamellae of P. 
funafutiensis are very numerous and appressed 
over the entire shell, whereas in P. philcloveri 
the lamellae are erect and only appressed over 
the spiral cords. The leading side of the aper- 
tural varix of P. funafutiensis has five strong 
concave troughs, a reflection of the strong ex- 



terior cords. The apertural varix of P. phil- 
cloveri is regularly wavy reflecting the spiral 
cords. 

Acknowledgments 

We wish to thank the following: Mr. Philip 
Bellin of Hawaii for donating specimens of 
Pygmaepterys bellini new species to the Natural 
History Museum of San Diego; Mr. Gene Ever- 
son of Lauderhill, Florida, for donating his 
specimen of P. bellini from the Philippine 
Islands; Mr. Victor Dan of Manila, Philippine 
Islands, for allowing us to study his specimens 
of P. philcloveri and for donating a specimen to 
our museum; Mr. Robert Yin of La Jolla, Cali- 
fornia, for bringing the specimens of P. phil- 
cloveri to our attention; Mr. Donald Pisor of 
San Diego, California, for allowing us to study 
his very fine example of P. funafutiensis 
(Hedley,' 1899). We are grateful to Mr. David K. 
Mulliner for the photography used in this paper. 
Dr. William K. Emerson and Mr. Walter E. 
Sage, III of the American Museum of Natural 
History read a draft of the manuscript. 

LITERATURE CITED 

Bartsch, P. 1915. Report on the Turton collection of South 
African Marine Mollusks with additional notes on other 
South African Shells contained in the United States 
Museum. Bull. 91 USNM. 1-305 pp. 54 pis. 

Hedley, C. 1899. The Mollusca of Funafuti. Mem. Aust. 
Mus. 3(7):397-488, 49 figs. Pt. 1. Gastropoda. 

Houart, R. 1984. Poirieria (Pazinotus) philcloveri, a new 
species from the Philippine Islands (Gastropoda: Murici- 
dae: Muricinae). Informations 12(2-3): 127-130. 1 pi. 

Radwin, G. and A. D'Attilio. 1971. Muricacean supraspecific 
taxonomy based on the shell and radula. Echo 4:55-67. 

Rafinesque, C. S. 1815. Analyse de la nature, ou tableau du 
univers et des corps organises. Barravecchia, Palermo. 

Vokes, E. 1978. Muricidae (Mollusca: Gastropoda) from the 
eastern coast of Africa. Ann. Natal Mus. 23(2):375-418, 
8 pis. 

Vokes, E. and A. D'Attilio. 1980. Pygmaepterys, a newly 
described taxon of Muricidae (Mollusca: Gastropoda) with 
description of three new species from the Cenozoic of the 
western Atlantic. Tulane Studies in Geo. and Paleo. 
16(2):45-54, 2 pis. 



14 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



MUREX HAMATUS HINDS, 1844, A LIVING WEST 

AMERICAN SPECIES ASSIGNED TO THE NEOGENE PACIPHILE 

GENUS, PTERORYTIS CONRAD (GASTROPODA: MURICIDAE). 

William K. Emerson 

Department of Invertebrates 

American Museum of Natural History 

New York, New York 10024 

ABSTRACT 
Pterorytis hamatus (Hinds), an inhabitant of Ecuadorian and Peruvian 
waters, is the only known extant species of this muricacean genus. Pterorytis was 
widely distributed in the tropical western Atlantic during the Neogene. By the end 
of the Pliocene, however, the constituents of this Paciphile genus apparently 
became extinct in the western Atlantic, with P. hamatus surviving on the Pacific 
side of the Panamanian land bridge. The typological specimens o/Murex hamatus 
were examined, and a live-collected specimen was studied. On the basis of oper- 
cular, radular and shell characters, the assignment of this species to the muricid 
subfamily Ocenebrinae is confirmed. 



Some twenty-five years have passed since my 
review of the muricid genus Pterorytis appeared 
(Emerson, 1959). At that time the genus was 
believed to consist of extinct east American 
Neogene species. More than a decade ago, how- 
ever, Vokes (1971, pp. 56, 141, and Vokes in 
Keen, 1971, p. 536) recognized that a long- 
misunderstood species from Ecuador, described 
by Hinds in 1844 as Murex hamatus, was a living 
representative of this Paciphile genus. Previous- 
ly, Hinds' species was referred to other muricid 
genera, including Tritonalia, Ocenebra and 
Ceratostoma and was erroneously placed in the 
synonymy of Ceratostoma lugubre (Broderip, 
1833), a species that also was originally de- 
scribed from Ecuador. 

Through the kindness of Carol Skoglund of 
Phoenix, Arizona, a specimen of Pteror^ytis 
hamatus, taken alive by shrimpers working out 
of San Pablo, Ecuador, was submitted to me for 
study. As the preservation of the soft parts of 
this specimen presented an opportunity to 
establish the taxonomic placement within the 
Muricidae of this rarely found species, the pre- 
sent study was undertaken. 

Family Muricidae Rafinesque, 1815 
Subfamily Ocenebrinae Cossmann, 1903 



Genus Pterorytis Conrad, 1862 

Pterorytis hamatus (Hinds, 1844) 

Figs. 1-5, 7-9 

Murex hamatus Hinds, 1844a, p. 128; Hinds, 1844b, p. 8, 
pi. 3, figs. 11, 12; Reeve, 1845, Murex, sp. 119, pi. 27, fig. 
119 ("Museum Belcher"); Sowerby, 1879, Murex. sp. 203, p. 
44, pi. 16, fig. 159 ("Voy. Sulph., p. 8"). 

Murex lugubris Broderip, Tryon, 1880, p. 124, pi. 37, fig. 
439 only; Keen 1958, p. 357, in part. Not M. lugubris 
Broderip, 1833. 

Tritonalia hamata (Hinds), Dall, 1909, p. 220, "Guayaquil, 
Ecuador, and south to Paita, Peru"); Smith, 1939, p. 15, 
(cites Dall's distributional data). 

Ceratostoma hamata (Hinds), Keen, 1966, p. 269, pi. 46 
fig. 11 ("figured syntype, from Belcher coll. to S. Hanley to 
H. Harvey; also figured by Reeve, [1845]"). 

Pterorytis hamatus (Hinds), Vokes, 1971, pp. 56, 141; 
Keen, 1971, p. 536, fig. 1039 ("BM Syntype", p. 951); Fair, 
1976. p. 47, pi. 23, fig. 360 ("BM(NH) Holotype (EH 
V[okes])", p. 131). 

Ocenebra? hamata (Hinds), Radwin and D'Attilio, 1976, 
pp. 121. 122, pi. 14. fig. 2 ("off Peru, Inst. Del Mar, Peru," 
p. 259). 

Type locality: "Bay of Guayaquil, [Ecuador], 
from a muddy floor, in twenty-one fathoms" 
[38 m]. 

Known range: Golfo de Guayaquil (type speci- 
mens) and off San Pablo, Guayas Province 
(AMNH 213692), Ecuador, and Paita, Peru 
(Dall, 1909, p. 220; cited specimens were not 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 15 




FIGS. 1-3. Pterorytis hamatus (Hinds, 1844), off San Pablo, Guayas Province, Ecuador (AMNH 213692); height = 38.6 mm. 




FIGS. 4 and 5. Original figures of Murex hamatus (Hinds, 
1844b, figs. 11, 12); height = 29.2 mm. 



found in the NMNH collection, teste J. 
Rosewater, August 10, 1984). 

Diagnosis: Shell rhomboid in outline, 23 mm 
to 40 mm in height. Spire elongated, of 3V2 



nuclear whorls; 4 post nuclear whorls. Six 
raised, spiniform varices per whorl ornamented 
with slightly recurved laciniations and one or 
two major ribs on faces of varices. Aperture 
oval, with an acute labial tooth anteriorly, 
marked here and on the previous varices of body 
whorl by a V-shaped notch behind varical tooth. 
Canal short, closed, grooved behind. Color pale- 
yellow to tan (modified after Fair, 1976, p. 47). 

Radular characters: Typical of Ocenebrinae; 
compare our Figure 7 with our Figure 6 of the 
radular dentition of Ocenebra erinaceus (Linne, 
1758), the type species of Ocenebra Gray, 1847. 

Opercular characters: Ocenebrine, see Figs. 
8, 9. 

Remarks: The larger of the two "syntypes" of 
Murex hamatus in the British Museum (Natural 
History) (1907.12.30.134, here illustrated, 
Figures 4, 5), measures 29.2 mm (sans nucleus). 
This specimen (29.2 mm in length) appears to be 
the one figured by Hinds (1844b, pi. 3, Figs. 11, 




FIGS. 6 and 7. 6, Radular dentition of Ocenebra erinaceus (Linne, 1758), after Radwin and 
D'Attilio, 1976, fig. 73. 7, Radular dentition of Pterorytis hamatus (Hinds, 1844), (AMNH 
213692), drawing by Anthony D'Attilio. left side, central tooth; right side, 1 lateral tooth. 



16 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 




FIGS. 8 and 9. Operculum of Pterorytis ham.atus 
(Hinds, 1844), (AMNH 213692), left side, internal 
view; right side, external view; drawings by 
Anthony D'Attilio; greatly enlarged. 



12) and Reeve (1845, Murex, pi. 27, Fig. 119), 
despite the fact that Hinds (1844a, p. 128) cites 
13V2 English lines for the axis of the shell [ = 28.5 
mm]. 13.5 French lines would be 30.3 mm. Keen 
(1966, p. 269) translated it to 34 mm. Keen (op. 
cit.) also recorded a second specimen, a 
topotype, in the general collection of the British 
Museum (1842.1.22.418), which Hinds in 1842 
had labeled "Murex, sp.". It is a juvenile, 
measuring 23.2 mm in height, with an immature 
outer lip. The present specimen from off San 
Pablo, Ecuador (AMNH 213692, here illus- 
trated, Figures 1-3, 7-9), is a larger (38.6 mm), 
more robust example of this species. The 
specimen identified as ?Ocenebra hamata by 
Radwin and DAttilio (1976, pi. 14, Fig. 2, from 
"off Peru") may represent another species. The 
shell is larger (66.8 mm in height), with the 
labial tooth situated medially, and it is colored a 
darker tan, tinged with brown. 

No other specimens of this species were 
located in any of the leading U.S. museum col- 
lection nor in such private collections as that of 
Helen DuShane and Donald R. Shasky. The 
failure to find additional specimens in these col- 
lections attests to the apparent rarity of this 
species. 

Systematics and Zoogeography 

I'trrorytis hintmtus appears to be most closely 
related to the type species of Pterorytis, P. um- 
brifer (Conrad," 1832, p. 17, pi. 3, Fig. 1; Olsson 
and Harbison, L953, pi. 35, Fig. 2; Emerson, 



1959, Fig. 1), a species not uncommonly found in 
Pliocene deposits (Yorktown formation) of 
Virginia. Both species have a shell well-marked 
by a V-shaped indentation behind the acute 
labial tooth, as well as six foliated and spiniform 
varices. Pterortyis hamatus is, therefore, 
referable to Pterorytis (sensu stricto) and is the 
only known survivor of this Paciphile genus, 
which during the Neogene flourished in the 
tropical western Atlantic. The other extinct 
species of Pteroi'ytis (see Olsson and Harbison, 
1953, p. 252; Emerson, 1959, p. 4; Olsson and 
Petit, 1964, p. 549; Vokes, 1971, p. 141) have 
been referred to the subgenus Neurarhytis 
Olsson and Harbison (1953, p. 252) of which P. 
jluviana (Da\\, 1903, p. 1633, pi. 60, Figs. 20, 21; 
Emerson, 1959, Fig. 2) is the type species. 
These taxa have heavier shells of moderate size, 
with four wide, terminally recurved, finely 
foliated varices per whorl and a weakly devel- 
oped labial tooth without a prominent labial 
suture. 

Pterorytis (Mierorhytis) pecki (Emerson, 
1959, p. 6, Fig. 4) from the Miocene of Veracruz, 
Mexico, may be referable to the genus Cerato- 
stoma Herrmannsen, 1846, type species C. nut- 
talli (Conrad, 1837, p. 264, pi. 20, Fig. 22), as 
Vokes (1971, p. 125) has indicated. However, P. 
peeki, the type species of Mierorhytis Emerson 
(1959), does possess a marginal indentation 
below the labial tooth, which is characteristic of 
Pterorytis, and has a shorter spire than typical 
species of Ceratostoma. 

At the present time the geographical range of 
Ceratostoma is from Japan to northern Mexico 
(Cape San Lucas, Baja California Sur). Vokes 
(1964, p. 23; 1974, p. 8), however, reports in the 
Miocene of Silverdale, North Carolina (Trent 
marl of Richards, 1943) the presence of several 
amphi-North Pacific muricid genera, including 
Ceratostoma, that are no longer living in the 
western Atlantic. During the Neogene, the 
genus Ceratostoma is known to have been pre- 
sent in western Atlantic waters (North Carolina 
and possibly from Vera Cruz, Mexico), as well as 
in northeastern Pacific waters (Mio-Pliocene of 
California, Hall, 1959). 

Acknowledgments 

I am deeply indebted to Carol Skoglund for 
her kindness in calling to my attention and 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 17 



donating her specimen to the AMNH. I thank 
John Taylor (BM(NH)) for the loan of Hinds' 
typological specimens and Anthony D'Attilio 
and Barbara Myers (SDNHM) for providing the 
line drawings of the radular dentition and the 
operculum and for preparing the radular mount, 
respectively. The following friends and col- 
leagues assisted by searching their collections 
for specimens: Robert Robertson and Mary A. 
Garback (ANSP), Terrence M. Gosliner (CAS), 
James H. McLean (LACMNH), Ruth D. Turner 
and David H. Backus (MCZ at Harvard), Joseph 
Rosewater (NMNH), Anthony D'Attilio 
(SDMNH), Helen DuShane of Whittier, CA, and 
Donald R. Shasky of Redlands, CA. George and 
Wylda Stephens of Virginia Beach, VA, and 
Richard E. Petit of North Myrtle Beach, SC, 
generously provided fossil specimens of 
Pterorytis. 

I also acknowledge the contributions of my 
AMNH colleagues: Walter E. Sage, III for 
technical services, and Peter Harries and Jeff 
Teitelbaum for the photography. 



LITERATURE CITED 

Broderip, W. J. 1833. Characters of new species of Mollusca 

and Conchifera, collected by Mr. Cuming. Proc Zool. Soc. 

London, for 1832, pp. 173-179 (Jan. 14, 1833). 
Conrad, T. A. 1832. Fossil shells of the Tertiary formations 

of North America. Philadelphia, vol. 1, pp. 1-28, pis. 1-14. 
1837. Descriptions of new marine shells from 

upper California, collected by Thomas Nuttall, Esq. Jour. 

Acad. Nat. Sci. Philadelphia, vol. 7, pp. 227-268, pis. 

17-20. 

1862. Catalogue of the Miocene shells of the 



Atlantic slope. Proc. Acad. Nat. Sci. Philadelphia, vol. 14, 

pp. 559-582. 
Dall, W. H. 1903. Contributions to the Tertiary fauna of 

Florida. Trans. Wagner Free Inst. Philadelphia, vol. 3, pt. 

4, pp. l-xiv + 1219-1654, pis. 48-60. 
1909. Report on a collection of shells from Peru, 

with a summary of the littoral marine Mollusca of the 

Peruvian zoological province. Proc. U.S. Nat. Mus.. vol. 

37, no. 1704, pp. 147-294, pis. 20-28. 
Emerson, W. K. 1959. The gastropod genus Pterorytis. 

Amer. Mus. Novitates, no. 1974, 8 pp., 4 figs. 
Fair, R. H. 1976. The Murex book: an illustrated catalogue of 

Recent Muricidae (Muricinae, Muricopsinae, Ocenebrinae). 

Honolulu, 138 pp., 56 text figs., 21 pis. 



Hall. C. A. Jr. 1959. The gastropod genus I'iratostoma. 

Jour. Paleont., vol. 33, no. 3, pp. 428-434, 4 text figs. pis. 

61-63. 
Herrmannsen, A. N. 1846. Indicis generum malacozoorum 

primordia, Kassel, vol. 1. pp. 1-232, [pp. 233-637, 1847]. 
Hinds, R. B. 1844a. Descriptions of new species of Scalaria 

■and Murex. from the collection of Sir Edward Belcher, CB. 

Proc. Zool. Soc. London, for 1843, pp. 124-129 (March, 

1844). 
1844b. The zoology of the voyage of H.M.S. 

Sulphur under the command of Capt. Sir Edward Belcher 

. . . during 1836-1842, London, Mollusca, pt. 1, pp. 1-24, 

pis. 1-7 (July, 1844). 
Keen, A. M. 1958 Sea shells of tropical west America. 

Stanford, California, xi + 624 pp., illus. 
1966. West American mollusk types in the Brit- 
ish Museum (Natural History) II. Species described by R. 

B. Hinds. The Veliyer. vol. 8, no. 4, pp. 265-275, 6 text 

figs., pis. 46-47. 

1971. Sea Shells of tropical west America, 2nd 



ed., Stanford, California, xiv + 1,064 pp., illus. 
Olsson, A. A., and Anne Harbison. 1953. Pliocene Mollusca 

of southern Florida. Monogr. Acad. Nat. Sci. Philadel- 
phia, no. 8, pt. 1, pp. 27-361, pis. 1-65. 
Olsson, A. A., and R. E. Petit. 1964. Some Neogene Mollusca 

from Florida and the Carolinas. Bull. Amer. Paleont., vol. 

47, no. 217, pt. 2, pp. 527-574, pis. 77-83. 
Radwin, G. E., and A. D'Attilio. 1976. Murex Shells of the 

World, an illustrated guide to the Muricidae, Stanford, 

California, 284 pp., 98 text figs., 32 pis. 
Reeve, L. A. 1845. Conchologia Iconica, or illustrations of 

the shells of molluscous animals, London, Monograph of 

the genus Murex, text + Murex pis. 1-34 [pi. 27, Aug. 

1845], 
Richards, H. G. 1943. Additions to the fauna of the Trent 

marl of North Carolina. Jour. Paleont., vol. 17, no. 5, pp. 

518-526, pis. 85, 86. 
Smith, Maxwell. 1939. An illustrated catalogue of 'the Recent 

species of the rock shells. Muricidae, Thaisidae, and Coral- 

liophilidae, Lantana, Florida, 83 pp., text figs, a-z, 21 pis. 
Sowerby, G. B. II. 1879. Thesaurus Conch yliorum, or mono- 
graphs of the genera of shells. London, vol. 4, Monograph 

of the genus Murex Linnaeus, pts. 33-35, 55 pp., pis. 

380-403 [Murex, pis. 1-24]. 
Tryon, G. W., Jr. 1880. Manual ofConchology, ser. 1, vol. 2, 

Muricidae, Purpuridae, Philadelphia, 289 pp., 70 pis. 
Vokes, E. H. 1964. Supraspecific groups in the subfamilies 

Muricinae and Tritonaliinae (Gastropoda: Muricidae). 

Malaeologia, vol. 2, no. 1, pp. 1-41, pis. 1-3. 
1971. Catalogue of the genus Murex Linne 

(Mollusca: Gastropoda; Muricinae, Ocenebrinae). Bull. 

Amer. Paleont., vol. 61, no. 268, 141 pp. 

1974. A new species and subgenus of Australian 



Demomurex (Gastropoda: Muricidae). Jour. Malac. Soc. 
Australia, vol. 3, no. 1, pp. 1-14, pis. 1-3. 



18 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



CORBICULA FLUMINEA (BIVALVIA: CORBICULIDAE) IN THE 
STATE OF WASHINGTON IN 1937, AND IN UTAH IN 1978 

Clement L. Counts, III 

College of Marine Studies 
University of Delaware 
Lewes, Delaware 19958 



Washington 

The exotic Asiatic bivalve, Corbicula Jluminea 
(Muller, 1774) was first detected in North 
America at Nanaimo, Vancouver Island, British 
Columbia, in 1924 (Counts, 1981). The first 
report of C. jluminea in United States waters is 
that of Burch (1944) for specimens collected 
along the Columbia River at Knappton, Pacific 
County, Washington, in 1938. These are the 
earliest published records for C. Jluminea in 
North America (McMahon, 1982, 1983; Counts, 
1983). 

A survey of the Corbiculidae collections held 
in the Department of Malacology of the Los 
Angeles County Museum of Natural History 
(LACM), conducted in June 1984, revealed a lot 
of Corbicula Jluminea collected in April 1937 at 
Raymond, Pacific County, Washington (LACM 
64359). The label accompanying the specimens 
states "Introduced from Japan. Immaculate 
Heart Collection. A. Burch". It does not specify 
a body of water as a collection locality. No 
details are available on either the Immaculate 
Heart Collection or the collector. The shape and 
color of the specimens is consistant with the 
"white form" described by Hillis and Patton 
(1982). A review of zoogeographic records for C. 
ihinmiiii in Washington found thai specimens 
were collected from the Willapa River at Ray- 
mond in 1971 (Counts, 1983) indicating that C. 
Jluminea has survived in this region of Washing- 
ton and suggesting that LACM 64359 may be 
representative of the population of origin. 

Although LACM 64359 does not significantly 
alter the date of the introduction of Corbicula 
Jluminea into United States waters, it is signifi- 
cant since it reinforces the hypothesis of a west 
coast introduction during the 1920's-1930's 
(Britton and Morton, 1979). 

Acktmtrlnhin/cnts: I would like to thank Mr. C. 
Clifton Coney and Dr. James H. McLean, Los 



Angeles County Museum of Natural History, for 
their assistance. 

Utah 

The Asiatic bivalve, Corbicula Jluminea 
(Muller, 1774) has been reported from Utah only 
in general geographic terms (Cherry, et aL, 
1980a, b; McMahon, 1982, 1983). These reports 
are in the nature of either lists of states where 
C. Jluminea does or does not occur or United 
States maps with the State of Utah colored to 
indicate the presence of the species. No precise 
locality descriptions have been published for C. 
Jluminea in Utah. A survey of 26 malacological 
collections held in museums throughout the 
United States, conducted between 1979 and 
1982 failed to reveal any specimens collected in 
Utah (Counts, 1983). 

A survey of the malacological collections of 
The Ohio State University Museum of Zoology 
(OSUM) conducted in June 1984 revealed two 
lots of Corbicula Jluminea collected in Utah. 
Both lots (OSUM 52430 and OSUM 52431) were 
collected in the Sevier Reservoir (also known as 
Yuba Reservoir), 15.2 km northeast of Scipio, 
Juab County, Utah on 4 July 1978 by Richard L. 
Denton (Fig. 1). The shape and color of the 
specimens is consistant with the "white form" of 
Hillis and Patton (1982). 

The Sevier River flows approximately 520 km 
from the Paunsaugunt Plateau of southwestern 
Utah north to Juab County where it then flows 
southwest to Sevier Lake. The river is located in 
the Great Basin and thus has no outlet to the 
oceans. Further, there is no connection with any 
other river in which Corbicula Jluminea is 
known to exist. This indicates that C Jluminea 
was introduced into the Sevier River by means 
other than normal movements of the bivalves in 
the substratum. Zoogeographic studies of C. 
ih < in i in a reveal the nearest known population is 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 19 



H 




FIG. 1. Location of Corbicula fluminea in the Sevier River, 
Utah (Scale bar = 100 km). 



located in Lake Meade of Arizona-California- 
Nevada (Counts, 1983). Whether the agent of in- 
troduction into the Sevier River was man or 
waterfowl is speculative at present. 

Acknowledgments: I would like to thank Dr. 
David H. Stansbery, The Ohio State University 
Museum of Zoology, for allowing me to examine 
their collections. Both of these researches were 



supported by the U. S. Nuclear Regulatory 
Commission (Contract No. NRC-03-84-063). 

LITERATURE CITED 

Britton, J. C. and B. Morton. 1979. Corbicula in North 
America: the evidence reviewed and evaluated. IN: Pro- 
ceedings of the First International Corbicula Symposium, 
J. C. Britton, Ed. Texas Christian University Research 
Foundation (Fort Worth), pp. 250-287. 

Burch, J. Q. 1944. Checklist of west American mollusks. 
Minutes, Concol. Club Southern California 38:18. 

Cherry, D. S.. J. Cairns, Jr. and R. L. Graney. 1980a. Asiatic 
clam invasion: causes and effects. Water Spectrum 
12:18-24. 

Cherry, D. S., J. H. Rodgers, Jr., R. L. Graney and J. H. 
Cairns, Jr. 1980b. Dynamics and control of the Asiatic 
clam in New River. Virginia. Bulletin, Virginia Water 
Resources Center, 123:1-72. 

Counts, C. L., III. 1981. Corbicula fluminea (Bivalvia: 
Sphaeriacea) in British Columbia. The Nautilus 95(1): 
12-13. 

1983. Bivalves in the genus Corbicula Miihlfeld, 

1811 (Mollusca: Corbiculidae) in the United States: sys- 
tematics and zoogeography. Ph. D. Dissertation. Univer- 
sity of Delaware, xxii + 451 pp. 

Hillis, D. M. and J. C. Patton. 1982. Morphological and elec- 
trophoretic evidence for two species of Corbicula 
(Bivalvia: Corbiculidae) in North America. American 
Midland Naturalist 108(l):74-80. 

McMahon, R. F. 1982. The occurrence and spread of the in- 
troduced Asiatic freshwater bivalve, Corbicula. fluminea 
(Muller) in North America: 1924-1981. The Nautilus 
96(4):134-141. 

1983. Ecology of an invasive pest bivalve, Cor- 
bicula. IN: The Mollusca, Vol. 6, Ecology, W. D. Russell- 
Hunter. Ed. Academic Press (New York), pp. 505-561. 



TROPICAL VERONICELLID, LAEVICAULIS ALTE (FERUSSAC), 
ESTABLISHED IN SOUTHERN TEXAS 

Raymond W. Neck 

Texas Parks and Wildlife Department 
4200 Smith School Road 

Austin, Texas 78744 



A number of tropical gastropods have been in- 
troduced into urban locations in Brownsville, 
Cameron County, Texas (Neck, 1976). Included 
are several veronicellid slugs, two of which were 
reported in an earlier communication (Neck, 
1976). An additional species has been observed 
and was tentatively identified as Pseudoveroni- 



cella liberiana (Gould) (Neck, 1981). Recently, 
specimens from this population were sent to 
Lothar Forcart of Basel, Switzerland, and Jose 
Willibaldo Thome of Porto Alegre, Brazil, both 
of whom identified this species as Laevicaulis 
alte (Ferussac, 1821). 
Laevicaulis alte was most likely native to cen- 



20 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



tral or eastern Africa (Forcart, 1953; in litt.). 
The type locality of this taxon is Pondicherry, 
India (Forcart, 1969). Human-mediated disper- 
sal has allowed this species to establish popula- 
tions in Madagascar, India, Indonesia, the 
Philippines, Australia and various island groups 
in Oceania (Forcart, 1953; Solem 1959, 1964). 

This southern Texas record apparently repre- 
sents the first establishment of L. alte in North 
America. Neither Hanna (1966) nor Dundee 
(1974) list L. alte, although this species has been 
established in Hawaii since the 1920's (as 
Veronicella leydigi (Simroth), in Cockerell, 
1925). Summary papers by Baker (1925) and 
Thome (1975a, b) do not list L. alte for the 
Americas. 

First observed in Brownsville in 1975, L. alte 
has subsequently become the most abundant 
veronicellid in urban residential yards. Later 
reports will discuss life history and interactions 
with other introduced veronicellids. 

I thank Lothar Forcart and Jose Willibaldo 
Thome for their prompt identification of the 
slug. 

LITERATURE CITED 
Baker, H. B. 1925. North American Veronieellidae. Proc. 



Acad. Nat. Sci. Philadelphia 77:157-184. 
Cockerell, T. D. A. 1925. A visit to the Hawaiian Islands. 

The Nautilus 38:76-85. 
Dundee, D. S. 1974. Catalog of introduced molluscs of 

eastern North America (North of Mexico). Sterkiana 

55:1-37. 
Forcart, L. 1953. The Veronieellidae of Africa (Mollusca, 

Pulmonata). Ann. Musee Royal Congo Beige. Tervueren, 

Zool. 23:1-110. 
1969. Veronicellid land slugs from the New 

Hebrides, with description of Semperula solemi. new 

species. Fieldiana: Zoology 51(12):147-156. 
Hanna, G. D. 1966. Introduced mollusks of western North 

America. Occ. Papers California Acad. Sci. 48:1-108. 
Neck, R. W. 1976. Adventive land snails in the Brownsville, 

Texas area. Southwestern Naturalist 21:133-135. 
1981. Noteworthy gastropod records from 

Texas. Texas Conchologist 17:69-72. 
Solem, A. 1959. Systematics and zoogeography of the land 

and fresh- water Mollusca of the New Hebrides. Fieldiana: 

Zoology 43:1-238. 
1964. New records of New Caledonian non- 
marine mollusks and an analysis of the introduced mol- 
lusks. Pacific Science 18:130-137. 
Thome, J. W. 1975a. Estado atual da sistematica dos 

veronicelideos americanos (Mollusca, Gastropoda). Arq. 

Mus. Nac.. Rio de Janeiro 55:155-165. 
1975b. Os generos da familia Veronieellidae 

nas Americas (Mollusca; Gastropoda). Iheringia Zool. 

48:3-56. 



NEW RECORDS OF MARINE MOLLUSCA FROM 
KHOR ABDULLAH, IRAQ 

L. A. J. Al-Hassan and Z. I. Al-Hasani 

Marine Science Centre 

University of Basrah 

Basrah, Iraq 



During the period of November 1982 to 
November 1983 a number of mollusks were ob- 
tained from the surface of sediments in Khor 
Abdullah in the northwest section of the 
Arabian Gulf. 

The Khor Abdullah area is situated in a shal- 
low sea and much of the coastline is bordered by 
mud and sandy silt (S. A. Darmoian, personal 
communication). The depth ranges between 5 
and 12 meters. The new records include nine 
gastropods and sixteen bivalves: 



1. Euchelis asper (Gmelin, 1791) 

2. Turritella terebra (Linnaeus, 1758) 

3. Slellaria Solaris (Linnaeus, 1767) 

4. Tibia insulaechorab (Roding, 1798) 

5. Stromhus decorus persicus (Swainson, 1821) 

6. Neuerita didyma (Roding, 1798) 
V Finis gracilis (Suwerl>\ . 1825) 

8. Rapana rapiformis (Born, 1778) 

9. Inqui.stor griffithi (Gray, 1834) 

10. Siphonaria basseinensis (Melvill, 1893) 

11. Anadara antiquata (Linnaeus, 1758) 

12. Striarca sculpdlis (Reeve, 1857) 

13. Pinna murirnln (Linnaeus, 17fiS) 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 21 



14. Pinctada radiata (Leach, 1814) 

15. Pteria marmorata (Reeve, 1857) 

16. Isogonomon legumen (Gmelin, 1791) 

17. Malleus regulus (Forskal, 1775) 

18. Placuna placenta (Linnaeus, 1758) 

19. Trachycardium. enode (Sowerby, 1840) 

20. Gari occidens (Gmelin, 1791) 

21. Bassina callophyla (Philippi, 1836) 

22. Marcia hiantina (Lamarck, 1818) 

23. Paphia gallus (Gmelin, 1791) 

24. Periglypta reticulata (Linnaeus, 1758) 

The only previously published work on the 
area was by Ahmed (1975) which did not include 
the newly recorded species under consideration. 

I wish to thank Dr. R. Tucker Abbott of 
American Malacologists Inc. for checking the 



identifications and reviewing the manuscript. I 
also wish to thank Dr. A. Al-Hashimi of the 
Kuwait Institute for Scientific Research, Dr. S. 
A. Darmonian and Dr. S. D. Salman of the 
Marine Science Centre, University of Basrah, 
for lending me their specimens. 

LITERATURE CITED 

Ahmed, M. M. 1975. Systematic Study on Mollusca from 
Arabian Gulf and Shatt Al-Arab, Iraq. Centre for Arab 
Gulf Studies, University of Basrah, Iraq. pp. 78. 

Allouse, Bashir E. 1956. A Bibliography on the Inverte- 
brate Fauna of Iraq and Neighbouring Countries. I. 
Molluscs. Publication no. 8, Iraq Natural History Museum. 
32 pp. 



DISTRIBUTION OF THE SNAIL, MELAMPUS BIDENTATUS, AND 

THE MUSSEL, GEUKENSIA DEMISSA, ALONG THE 

PATAGUANSET ESTUARY (CONNECTICUT) IN RELATION TO 

SALINITY AND OTHER TIDAL MARSH INVERTEBRATES 

Paul E. Fell and John H. Williams 

Department of Zoology 

Connecticut College 
New London, CT 06320 

ABSTRACT 
A survey was made of the tidal marshes along the Pataguanset Estuary in 
eastern Connecticut to determine the distributions of Melampus bidentatus Say, 
Geukensia demissa Dillwyn and a few other invertebrates that are often asso- 
ciated with these mollusks. Salinity conditions at six stations located along the 
length of the estuary were examined, and an attempt was made to relate the distri- 
bution of these animals to salinity. The high marsh species, Melampus bidentatus, 
Orchestia grillus and Philoscia vittata, and the low marsh fiddler crab, Uca 
minax, were distributed from the head of the estuary to its mouth. Geukensia 
demissa and Uca pugnax, which also inhabit the. low marsh, were absent at the 
head of the estuary where salinity sometimes falls to 0°/ 00 , but they were present in 
the marshes downstream. Toward the upstream extent of their distributions, the 
population densities of both Melampus and Geukensia sharply declined. The 
distributions of these mollusks were consistent with their known salinity 
tolerances, but it is not yet known to what extent salinity is a determining factor. 



Although the general community structure of 
tidal marshes is well-known (Teal, 1962; Day et 
al, 1973; Nixon and Oviatt, 1973; Subrahman- 
yam et al, 1976; Fell et al, 1982), relatively little 
information exists concerning the distribution 



of tidal marsh invertebrates in relation to salin- 
ity. Tidal marshes frequently extend far up 
estuaries, and consequently salinity may be an 
important factor influencing the occurrence of 
animals within such marshes. Most of the few 



22 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



previous studies on the relationship between 
salinity and the distribution of tidal marsh in- 
vertebrates have dealt with only a single or two 
closely related species (see Daiber, 1977 and 
1982 for reviews). Therefore almost no informa- 
tion is available on how salinity may influence 
community structure as a whole. 

A number of studies of tidal marsh mollusks 
have focused on the high marsh snail, Melampus 
hitlnita/us Say, or the low marsh mussel, Geu- 
kensia (formerly in Modiolus) demissa Dillwyn. 
In general surveys of the Delaware Bay and 
Chesapeake Bay areas, Melampus (Wass et al, 
1972; Leathern and Maurer, 1975; Parker, 1976) 
and Geukensia (Wass et al, 1972; Maurer et al, 
1974) were found to have an upper meso-and 
polyhaline distribution. Parker (1976) showed 
that although Melampus occurred in regions 
which exhibit a wide range of salinity, its popu- 
lation density was low where salinity was less 
than about 10°/ oo . Kerwin (1972) investigated 
the distribution of Melampus along an estuary in 
Virginia; but this snail did not occur in large 
numbers at any of the sampling stations, sug- 
gesting that factors other than salinity may be 
of primary importance in limiting its abundance 
within that system. 

The purpose of the current study was two- 
fold: 1) to examine the salinity conditions at six 
stations along the length of the Pataguanset 
Estuary in eastern Connecticut, and 2) to 
describe the occurrence of Melampus bidentatus 
and Geukensia demissa in relation to salinity 
and to the distribution of several other tidal 
marsh invertebrates. 




LONG ISLAND SOUND 

FIG. 1. The Pataguanset Estuary. Tidal marshes are in- 
dicated by stippling. Salinity sampling stations are 
designated by their distance in kilometers from the head of 
the estuary. Invertebrate sampling stations are shown by 
letters (A to F). E is Watts Island. 



Study Site; Methods 

The Pataguanset Estuary is located in eastern 
Connecticut and opens into Long Island Sound 
to the west of Niantic Bay from which it is 
separated by Black Point. The estuary, which is 
about 3.5 km long, is bordered by tidal marshes 
and on the south by the large tidal marsh Watts 
Island (Fig. 1). In most places the depth of the 
estuary ranges from about 1 to 2 m at high tide. 
Extensive beds of widgeon grass, Ruppia mari- 
tima, cover the tidal flats of the lower estuary in 
the region extending from about 1 to 3 km from 
the head. Water temperatures along the estuary 
reach about 25°C during the summer and fall 



below 0°C during the middle of the winter when 
much of the estuary may be covered by ice. 

Six stations were established along the 
estuary for studying salinity. These were 
located at 0.5 to 0.7 km intervals from the head 
of the estuary to a region near its mouth (Fig. 1). 
During a period extending from late spring 
through early fall of 1981 and June through 
August of 1982, surface and bottom salinities at 
high water of spring tides were determined 
every 2 weeks. Twice, once in late June and 
again in late July 1981, salinities were recorded 
at about hourly intervals covering half of a tidal 
cycle from low to high tide. Salinities were 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 23 



measured in the field with a Goldberg refrae- 
tometer (American Optical Co.). A few deter- 
minations of soil water salinities in the high 
marsh were made after squeezing the water 
from samples of peat and filtering the water 
through Whatman no. 1 filter paper. 

Previous studies on the distribution and abun- 
dance of Melampus hidentatus on Watts Island 
in the Pataguanset Estuary and on other Con- 
necticut tidal marshes have shown that this snail 
occurs at high densities in areas of the high 
marsh covered by Spartina patens, stunted 
Spartitai (litem iflont and .1 uncus gcrardi (Fell 
et al, 1982 and unpublished observations). For 
this study it was decided to sample Melampus in 
S. patens and Juncus because of the abundance 
of one or both of these plants in marshes along 
the entire estuary. During the summer of 1981 
Melampus was studied at six stations (Fig. 1). 
The population density of this snail was deter- 
mined using a 50 cm square wooden frame, 9 cm 
high, which was tossed onto the marsh in areas 
of chosen plant cover and at distances of about 2 
to 50 m from the water. The vegetation within 
the frame was clipped at the surface of the peat 
and all of the snails were collected and 
enumerated. At the same time the presence of 
two other high marsh invertebrates, Philnseia 
vittata (isopod) and Orchestia grillus 
(amphipod), was noted. The number of quadrats 
examined at each station is presented in Table 2. 

The abundance of Melampus, Philoscia and 
Orchestia at the three stations along the upper 
estuary was studied in greater detail during the 
summer of 1982. For this purpose 5 transects 
running perpendicular to the river bank and 
situated 15 m apart were set out at each site. 
Each transect was 25 m long, beginning at the 
lower edge of the high marsh; and six 50 cm 
square quadrats placed 5 m apart were exa- 
mined along each transect. Sampling was done 
during June, July and August at all three sta- 
tions. Transect sampling was used to eliminate 
bias in the selection of sampling sites. 

The population size of Geukensia demissa was 
estimated at each of 5 stations during 1981 by 
counting the number of animals within five 5.5 
m transects which extended along the banks of 
the estuary, except at station E (Watts Island) 
where the transects were located along a tidal 
creek. The width of the transects (ca 1 to 2 m) 



extended from the edge of the water at low tide 
to the upper edge of the tall Spartina alter- 
niflora zone. Sampling was done along sections 
of both banks to assure a representative sample. 
In addition, the relative abundance of the fiddler 
crabs, Uca minax and Uca pugnax, was deter- 
mined in these areas by digging from 50 to 
about 70 crabs from their burrows at low tide. 

Salinities 

There is considerable seasonal variation in 
salinity at stations in the upper estuary. For ex- 
ample, the surface salinity at the head of the 
estuary (St. 0) during high water of spring tides 
ranged from 0°/ oo during early June to more 
than 20°/ oo during late summer of 1981 (Fig. 2). 
However, at the head of the estuary the surface 
salinity may drop dramatically whenever there 
are heavy rains. In mid-September of 1981 the 
surface salinity at station during high water of 
a spring tide was only 2°/ 00 due to fresh water 
drainage. The range in surface salinities during 
high water of spring tides narrowed toward the 
mouth of the estuary, and at 1.8 km down- 
stream the range was only 24 to 32°/ 00 over the 
period of observation. During the summer of 
1982, surface salinities at the 3 stations of the 
upper estuary during high water of spring tides 
exhibited patterns similar to those of 1981, but 
they were often 5 to 10°/ oo lower for any par- 
ticular time. 

Salinities recorded at different times during 
the tidal cycle also exhibited substantial changes 



35 

30- 
^25- 

Q. 
Q. 

~ 20 - 

> 

1 15 

< 

*" 10 — I 

5 






FIG. 2. Surface salinities at four stations along the upper 
Pataguanset Estuary during high water of spring tides in 
1981. The stations are designated by their distance in 
kilometers from the head of the estuary. 



24 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



at stations in the middle and upper regions of 
the estuary (Fig. 3). At the station 1.1 km from 
the head of the estuary, the surface salinity 
ranged from 3°/oo at low water to 20°/oo at high 
water during neap tides in late June and late 
July of 1981. As would be expected, the surface 
salinities at the head of the estuary were fre- 
quently much greater during high water of 
spring tides than during the same period of neap 
tides (Figs. 3 and 4). Often the salinity at the 
surface and that at the bottom were identical or 
very similar; however, occasionally stratifica- 
tion was noted at the stations of the upper 
estuary. The difference between surface and 
bottom salinities at any given station usually did 
not exceed 10 o / oo and was greatest during high 
tide. However, when a perigee spring tide oc- 
curred during a period of heavy rain (16 Sept. 
1981), the surface salinity at the head of the 
estuary was 2°/oo at high water while the bottom 
salinity was 25°/ 00 . 

On two occasions the salinity of the water 
actually flooding the high marsh of the upper 



estuary was measured and found to be about the 
same as the surface salinity in the channel. How- 
ever, the salinity of the water just above the 
peat was somewhat different. For example, 
once when station A was flooded to a depth of 
about 20 cm the salinity at the surface was 2°/ 00 , 
as it also was in the channel, but close to the 
peat the salinity was 5 to 7°/ 00 . 

In late June and again in late July of 1981 the 
salinity of the soil water of the high marsh was 
measured at stations in the upper estuary dur- 
ing low tide. The soil water had a salinity of 7 to 
16°/ 00 near the head of the estuary and exhibited 
progressively high salinities at stations toward 
the mouth (Table 1). 

Animal Distribution 

Melarrvpus bidentatus was found at all stations 
along the estuary (Table 2). However, it was less 
abundant in the brackish marshes near the head 
of the estuary than in the marshes toward the 
mouth. Another pulmonate snail, Succirwa 
wilsoni Lea, which is typically found in fresh- 



35 - 

30 

25- 



«»■ 20 

Q. 



t ,5 " 

z 



10 - 
5 
0- 




• A 



-I 



HOURS 

FIG. 3. Surface salinities at six stations along the Pataguanset Estuary during the flooding phase of 
the tidal cycle. The stations are designated by their distance in kilometers from the head of the 
estuary. Solid circles joined by continuous lines show salinities during part of a neap tidal cycle on 22 
July 1981; open triangles indicate the low tide and high tide values during a neap tide on 23 June 
1981 ; and open circles joined by broken lines show salinities at station on 5 August 1981. LT = low 
tide. 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 25 



50 



JO 



20 



A 1981 N = 40 




B 1981 n 917 




C 1981 N: 277! 




-I — I — I — I — 1 



Z 50 



30 



2 



A 1982 N 4.' 




B 19 8 2 . N .- 2 5 3 




5 7 



II 13 



— i — l — l — i — i — i — i — | — i — i — i 
3 5 7 9 11 13 

SHELL LENGTH (mm) 



C 1982 _ n: 1231 




7 9 II 13 



FIG. 4. Size frequency distribution of Melampus bidentatus at 3 stations along the upper 
Pataguanset Estuary during 1981 and 1982. 



TABLE 1. Soil water salinities at stations in the upper 
Pataguanset Estuary during periods of neap tides. 





Salinity ("/„„) 


r.isi 


Station 


6/23 


7/22 


A 


7-11 


11-16 


B 


13-16 


20-25 


C 


- 


32 



water marshes, occurred together with Melam- 
pus at stations A and B. The vegetation in the 
higher regions of these brackish marshes con- 
sisted of Juncus gerardi and Spartina patens 
mixed with Solidago sempervirens, Potentilla 
anserina, Gerardia maritima, Panicum virga- 
tum and other species. Downstream the num- 
bers of Melampus increased until at 1 km or 
more from the head high densities of this snail 
were found in relatively pure stands of Juncus 
gerardi and of Spartina patens. Two inverte- 
brates that are normally associated with Melam- 
pus in salt water marshes, Philoscia vittata and 
Orchestia grillus, (Fell et al, 1982) were also 
distributed all along the Pataguanset Estuary, 
including the brackish marshes at its head 
(Table 2). 
Although the surveys of 1981 and 1982 were 



in agreement in showing a progressive decline 
in the population density of Melampus in the 
marshes of the upper estuary, the density of this 
snail at particular stations was much lower dur- 
ing the second summer (Table 3). In addition, 
during 1982 there was also a marked reduction 
in the proportion of smaller individuals (Fig. 4). 
It is not known whether these changes were 
related to the lower salinities occurring during 
1982 or to other factors such as high winter 
mortality. 

Geukensia demissa did not occur at the head 
of the estuary. Only a few small mussels were 
observed 0.5 km below this point, but at 1 km or 
more from the head these animals were moder- 
ately abundant (Table 3). Fiddler crabs often 
occur together with Geukensia in the low marsh. 
Two species of fiddler crab, Uca minax and Uca 
pugnax, were found; and one or both species 
were present at stations all along the Pataguan- 
set Estuary. Only Uca minax occurred at the 
head of the estuary and this species was the 
dominant fiddler crab at the station 0.5 km 
downstream. However, at all of the lower sta- 
tions Uca pugnax predominated. The distribu- 
tion of this fiddler crab was essentially the same 
as that of Geukensia. 



26 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 



TABLE 2. Abundance, no. per0.25m J (mean ± S.D.. range), of high marsh invertebrates along the Pataguanset Estuary 
in Connecticut. N = no. of quadrats examined. 







Mi In 


lupus liiilcnlntiis 






Phil 

N 


osda vittata 

1982 


Orrh 

N 


■stm grillus 


Station 


N r.'Mi 


N 


1981 


N 


1982 


1982 


A 




10 


4 + 5.0-15 


30 


1 + 5,0-24 


30 


3 ±3,0-8 


30 


3±3,0-10 


B 




20 


40 + 31,4-134 


30 


8 ±10.0-43 


30 


7+ 11,0-56 


30 


5 ±5,0-24 


C 




15 


184 + 99,14-336 


30 


41 + 35,0-146 


30 


6 + 6,0-31 


30 


4.5±4,0-16 


D 




5 


222 + 53,163-284 














E 


36 92 + 81.0-312 


15 


79 ±75,6-306 














F 




14 


112 ±83,2-263 















TABLE 3. Distribution of low marsh invertebrates along 
the Pataguanset Estuary in Connecticut during the summer 
of 1981 (number of Geukensia per 5x 5.5m transects). 



Station 


Geukensia demissa 


I'm 


■pugnax: Uca minax 


A 







0;64 


B 


3 




9:45 


C 


196 




43:7 


D 


410 




:'.1:1 


E 


143 




65:4 



Discussion 

Geukensia demissa was moderately abundant 
in the lower portions of the Pataguanset 
Estuary where the salinity of the water at high 
tide probably only rarely drops much below 
10°/ oo . On the other hand, it was absent from the 
marsh at the head of the estuary and was pre- 
sent in only small numbers 0.5 km downstream. 
At these stations the surface salinities at high 
tide were sometimes as low as to 2°/ 00 . Uca 
pugnax had a similar distribution, but Uca 
minax was abundant at stations along the banks 
of the upper estuary. Geukensia can survive and 
remain active at salinities as low as 8°/ 00 , but 
evidently is unable to tolerate prolonged sub- 
mergence by water of salinities below about 5°/ 00 
(Wells, 1961; Lent, 1969; Pierce, 1970; Maurer 
et al, 1974). Similarly, Teal (1958) has shown 
that Uca pugnax is less tolerant of low salinity 
than is Uca minax, succumbing within a few 
days if submerged in water with a salinity of 
7°/ o or lower (LD 50 =1.5 days at 0°/oo and 3 days 
at 7"/ 00 ). Eurthermore, when given a choice be- 
tween fresh water and 30°/oo sea water, Uca 
pugnax usually chose sea water while lira minax 
usually chose fresh water. The predominance of 
Uca minax in regions of low salinity and of Uca 
pugnax in regions of high salinity has been 
observed in a number of marsh systems (Teal, 



1958; Kerwin, 1971; Miller and Maurer, 1973). 
Competition between these 2 species of fiddler 
crabs, as well as other factors, undoubtedly also 
influence their distribution (Teal, 1958; Miller 
and Maurer, 1973; Daiber, 1977). The fact that 
Geukensia demissa and Uca pugnax have similar 
salinity tolerances and exhibit essentially the 
same distribution along the estuary lends 
strength to the hypothesis that salinity may be 
an important factor determining their distribu- 
tion within this system. 

Melampus bidentatus was found all along the 
Pataguanset Estuary, as were Orchestia grillus 
and Philoscia vittata. The high marsh is basical- 
ly a terrestrial environment most of the time, 
but it is regularly flooded by spring tides. Conse- 
quently, the salinity of the estuarine waters 
could be expected to exert less of an influence on 
the distribution of animals inhabiting this region 
than on those of the low marsh which is inun- 
dated more often and for longer periods. On the 
other hand, the density of Melampus was lower 
in the brackish marshes of the upper estuary 
and this may be related, at least in part, to the 
lower salinity of the soil water and/or more 
probably of the waters of inundation. Not only 
may low salinity have a direct influence on the 
snails but it may also act indirectly through its 
effects on the vegetation which is different in 
the brackish marsh. The observations of Parker 
(1976) further support this suggestion. In a 
study of 12 sites along the New Jersey and 
Delaware sides of Delaware Bay and 4 stations 
along the Broadkill River in Delaware, he also 
found that Melampus occurs in brackish 
marshes but that its population density is low 
where the salinity is less than about 10°/oo. 
Along a tributary of the York River in Virginia, 
Melampus was absent from marshes in regions 
where the mean surface salinity was below 4°/oo 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 27 



and was present in only small numbers in 
marshes located toward the mouth (Kerwin, 
1971 and 1972). In this system it appears that 
other factors besides salinity may be of major 
importance in limiting snail density. 

Melampus adults are remarkably tolerant of 
submergence in water ranging in salinity from 
full strength sea water to fresh water. They 
were found to survive total submergence in 
fresh water for a least one day at 20 °C and for 
at least 8 days at 10°C (Price, 1980; McMahon 
and Russell-Hunter, 1981). Melampus possesses 
a planktonic larva (Russell-Hunter, Apley and 
Hunter, 1972) which is also tolerant of low 
salinities (Parker, 1976). The larvae are highly 
active at salinities ranging from 15 to 40 o / oo , 
slightly less active at 10°/ oo and much less active 
at 5°/ 00 . About 90% of 2-day-old larvae were 
observed to survive for at least 10 hrs. in 
salinities ranging from 2.5 to 40°/ oo , but none 
survived that long in fresh water (Parker, 1976). 

Although the distributions of Melampus biden- 
tatus and Geukensia demissa along the 
Pataguanset Estuary are consistent with the 
salinity tolerances of these animals determined 
by laboratory experiments, it is not yet known 
whether salinity is, in fact, a major factor deter- 
mining the distribution and abundance of these 
animals. Among other factors that may be im- 
portant are predation, composition of the sub- 
stratum and flooding regime. Future studies 
should focus on more precisely defining the con- 
ditions which actually exist in various regions of 
the marsh system and on how these conditions 
affect all stages of the life history of the animals 
which live there. This will require that field 
measurements be made at frequent intervals, if 
not continuously, throughout the year and that 
field studies be accompanied by extensive 
laboratory experiments. In most laboratory 
studies, the effects of continuous exposure to a 
particular set of conditions are examined. 
However, in the marsh flooding is periodic, and 
therefore it would be desirable to look at the ef- 
fects of submersion by water of different 
salinities under regimes comparable to those 
that would be experienced by animals in the 
field. Until such comprehensive studies have 
been carried out, it will not be possible to make 
really meaningful statements concerning the 
causative factors which result in the observed 



distributional patterns. 

Acknowledgments 

Appreciation is expressed to Mary Ann Tilton, 
Elizabeth Brown, Mark Pereira, Kenneth 
Cadigan, Richard Orsen and Nanette Brodeur 
for assistance with the field work and to Dr. 
Dorothea Franzen for identifying Succinea 
wilsoni. This study was supported by grants 
from the Andrew Mellon and Seth Sprague 
Foundations. 



LITERATURE CITED 

Daiber. F. C. 1977. Salt-marsh animals: distribution related 
to tidal flooding, salinity and vegetation. In. V. J. Chap- 
man, ed., Ecosystems of the World 1. Wet Coastal Ecosys- 
tems. Elsevier Sei. Publ. Co., Amsterdam, Oxford, New 
York, pp. 79-108. 

1982. Animals of the Tidal Marsh. Van 

Nostrand/Reinhold Co., New York, 422 pp. 

Day, J. W. Jr., W. G. Smith, P. R. Wagner and W. C. Stowe. 
1973. Community structure and carbon budget of a salt 
marsh and shallow bay estuarine system in Louisiana. 
Publ. No. LSU-5G-72-04, 77 pp. 

Fell, P. E., N. C. Olmstead, E. Carlson, W. Jacob, D. 
Hitchcock and G. Silber. 1982. Distribution and abundance 
of macroinvertebrates on certain Connecticut tidal 
marshes, with an emphasis on dominant molluscs. 
Estuaries 5:234-239. 

Kerwin, J. A. 1971. Distribution of the fiddler crab (Uca 
minax) in relation to marsh plants within a Virginia 
estuary. Chesapeake Set. 12:180-183. 

1972. Distribution of the salt marsh snail 

(Melampus bidentatus Say) in relation to marsh plants in 
the Poropotank River Area, Virginia. Chesapeake Sci. 
13:150-153. 

Leathern, W. and D. Maurer. 1975. The distribution and 
ecology of common marine and estuarine gastropods in the 
Delaware Bay area. The Nautilus 89:73-79. 

Lent, C. M. 1969. Adaptations of the ribbed mussel, Modio- 
lus demissus (Dillwyn), to the intertidal habitat. Amer. 
Zool. 9:283-292. 

Maurer, D.. L. Watling and G. April. 1974. The distribution 
and ecology of common marine and estuarine pelecypods 
in the Delaware Bay area. The Nautilus 88:38-45. 

McMahon, R. F. and W. D. Russell-Hunter. 1981. The 
effects of physical variables and acclimation on survival 
and oxygen consumption in the high littoral salt-marsh 
snail, Malampus bidentatus Say. Biol. Bull. 161:246-269. 

Miller, K. G. and D. Maurer. 1973. Distribution of the fiddler 
crabs, Uea pugnax and Uca minax, in relation to salinity in 
Delaware rivers. Chesapeake Sci. 14:219-221. 

Nixon, S. W. and C. A. Oviatt, 1973. Ecology of a New- 
England salt marsh. Ecol. Monogr. 43:463-498. 

Parker, N. H. 1976. The distribution, growth and life history 
of Malampus bidentatus (Gastropoda: Pulmonata) in the 
Delaware Bay region. Master's Thesis. Univ. Delaware. 
65 pp. 



28 THE NAUTILUS 



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Vol. 99(1) 



Pierce, S. K. ,Ir. 19T0. The water balance of Modiolus 
(Mollusca: Bivalvia: Mytilidae): osmotic concentrations in 
changing salinities. Comp. Biochem. Physiol. 36:521-533. 

Price, C. H. 1980. Water relations and physiological ecology 
of the salt marsh snail, Melampus bidentatus Say. Jour. 
Exp. Mar. Biol. Ecol. 45:51-68. 

Russell-Hunter, W. D., M. L. Apley and R. D. Hunter. 1972. 
Early life-history of Melampus and the significance of 
semilunar synchrony. Biol. Bull. 143:623-656. 

Subrahmanyam, C. B., W. L. Krucznski and S. H. Drake. 
1976. Studies on the animal communities in two north 



Florida salt marshes part II. macroinvertebrate com- 
munities. Bull. Mar. Sci. 26:172-195. 
Teal, J. M. 1958. Distribution of fiddler crabs in Georgia 

salt marshes. Ecology 39:185-193. 
1962. Energy flow in the salt marsh ecosystem 

in Georgia. Ecology 43:614-624. 
Wass, M. L. et al. 1972. A check list of the biota of the lower 

Chesapeake Bay. Spec. Sci. Rep. No. 65 Virginia Inst. 

Mar. Sci. pp. 1-290. 
Wells, H. W. 1961. The fauna of oyster beds with special 

reference to the salinity factor. Ecol. Monogr. 31:239-266. 



TWO NEW SPECIES OF LYRIA FROM THE 
WESTERN ATLANTIC (GASTROPODA: VOLUTIDAE) 

William K. Emerson 

Department of Invertebrates 

American Museum of Natural History 

New York, New York 10024 

ABSTRACT 
Lyria leonardi n. sp. and Lyria russjenseni n. sp. are described from recently 
collected specimens obtained in moderate depths off southwestern Puerto Rico. 
The former species is also known from the Gulf of Triste, Venezuela, and off 
Grenada in the Lesser Antilles on the basis of fragmental specimens. Both taxa 
are compared with extant and extinct species q/*Lyria occurring in the Caribbean 
region. 



The volutid genus Lyria (sensu stricto) is 
represented in the Tertiary of the western 
Atlantic region by eight extinct species (Hoerle 
and Vokes, 1978) and by six extant species, in- 
cluding the two new taxa described herein 
(Weaver and duPont, 1970; Bayer, 1971). I take 
pleasure in naming the new species in honor of 
Fred L. Leonard and Russell H. Jensen, who 
kindly called my attention to specimens of these 
taxa and generously donated their respective 
specimens to the American Museum of Natural 
History (AMNH) type collection. 

The previously known western Atlantic 
Recent species that have been referred to the 
nominate subgenus are: 

1. Lyria beauii (Fischer and Bernardi, 1857), 
pi. 9, figs. 1, 2; Dance, 1969, pi. 16, fig. c; 
Weaver and duPont, 1970, pi. 4, figs. I, J; 
Pointier, 1981, pi. 1, figs. 1-4; and Abbott and 
Dance, 1982, p. 213, Type locality: Marie- 
Galante, Lesser Antilles. Known only from a 



few specimens taken in the Lesser Antilles, 
most recently from off Guadeloupe Island. 

2. Lyria archeri (Angas, 1865), p. 55, pi. 2, 
figs. 4, 5; Weaver and duPont, 1970, pi. 7, figs. 
G, H; Abbott, 1974, p. 245, fig. 2675 (not L. 
beauii); Pointier, 1981, pi. 2, figs. 6-14; Abbott 
and Dance, 1982, p. 213. Type locality: Montser- 
rat, Lesser Antilles, recently obtained off Marti- 
nique (AMNH coll. 183213). R. T. Abbott re- 
ports (in lit.) that Lesley Sutty collected speci- 
mens in Guadeloupe in 1969. Dall (1907, p. 351) 
referred this species to the genus-group taxon 
Enaeta H. & A. Adams (1853, vol. 1, p. 167) in 
the mistaken belief that the outer lip had similar 
labial dentition. In Enaeta. a blunt, tooth-like 
projection occurs near the midpoint of the outer 
lip near the margin of the labrum, (Hoerle and 
Vokes, 1978, p. 115). In Lyria archeri, the edge 
of the labrum is weakly serrated and pustule- 
like denticles form at the marginal base of some 
of the serrations inside the outer lip. These 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 29 



"teeth" are prominent in the holotype (Weaver 
and duPont, 1970, pi. 7, fig. H). As Try on (1882, 
p. 104) pointed out, however, the shell of Lyria 
archeri somewhat resembles that of the Indo- 
Pacific Lyria (L.) ynitraeformis (Lamarck, 
1811). This species apparently is not closely 
allied to the other living Lyria in the Caribbean 
region. 

3. Lyria vegai Clench and Turner, 1967, fig. 
1; Weaver and duPont, 1970, pi. 6, figs. F, G; 
Abbott, 1974, p. 245, fig. 2676; Pointier, 1981, 
pi. 1, fig. 5; Abbott and Dance, 1982, p. 214 
(holotype illus.). Type locality: "Cabo Rojo, Prov. 
Pedernales, Repiiblica Dominicana, Hispaniola", 
in a fish trap. Known only from the holotype. 

4. Lyria cordis Bayer, 1971, figs. 58 (shell), 
59 (living animal), 60 (radula), 61 (a, gross 
anatomy; b, operculum); Abbott, 1972, p. 139 
(living animal), Abbott, 1974, p. 245, fig. 2677; 
Pointier, 1981, pi. 1, fig. 6; Abbott and Dance, 
1982, p. 214 (holotype). Type locality: "Carib- 
bean Sea, 20 miles ESE of Sto. Domingo, Island 
of Hispaniola, 18° 21.0' N, 69° 14.3' W, depth 
174 m." Known only from 2 specimens from the 
type locality. This is the type species of the 
genus-group taxon, Cordilyria Bayer (1971, p. 
204). Notwithstanding the fact that axial sculp- 
ture occurs only on the first and second post 
nuclear whorls in the type species (L. cordis) as 
well as in Lyria vegai, and axial costae are 
prominent on the body whorl and the earlier 
whorls of Lyria beauii, L. russjenseni n. sp. and 
L. leonardi n. sp., these five species appear to be 
more closely related to each other than to Lyria 
archeri. They form a species complex for which 
the subgenus Cordilyria is available, if recogni- 
tion is subsequently deemed warranted on the 
basis of anatomical differences with the Indo- 
Pacific Lyria. For the present, Lyria archeri 
seems best retained in Lyria (sensu stricto). 

The New World representatives of the Cordi- 
lyria species complex occur in moderately deep 
water in the Caribbean Sea and are rarely found 
in collections. All the specimens I have exa- 
mined of the two species described here were 
dead-collected. Most appear to have been oc- 
cupied by hermit crabs, which would account for 
the presence of these shells in baited fish traps. 
The shells possess one or more octopus drill 
holes, suggesting that the specimens were the 
victims of octopod predation. 



Family Volutidae Rafinesque, 1815 
Subfamily Lyriinae Pilsbry and Olsson, 1954 

Genus Lyria Gray, 1847 
Lyria Gray, 1847, p. 141; type species by 
original designation: Voluta nucleus Lamarck, 
1811, Recent, Indo-Pacific. 

Lyria leonardi new species 
Figures 1 to 6 

Lyria beauii Fischer and Bernardi, Dall, 1907, 
p. 351, fragmental specimen, National Museum 
of Natural History (NMNH) 87718, near 
Grenada, in 133.5 m. Not Lyria beauii (Fischer 
and Bernardi, 1857). 

Lyria cf. limata Hoerle and Vokes, Petuch, 
1981, p. 331, figs. 75, 76, Golfo de Triste, Vene- 
zuela, in 16 m. Not Lyria (L.) limata Hoerle and 
Vokes, 1978, p. Ill, pi. 1, figs. 4, 5, Chipola For- 
mation, Florida, Miocene. 

Diagnosis: Ovately fusiform shell, large for 
genus, attaining 100 + (?) mm in length, of 8V2 
whorls; axial sculpture of 11 to 14 weakly folded 
ribs; color tannish white; spirally banded by ir- 
regular squarish blocks of brown below the 
suture and with 3 similar spiral bands on the 
body whorl; spirally threaded by 6 to 7 brown, 
strongly penciled lines on the body whorl, with 1 
to 3 similar spiral lines on the earlier post 
nuclear whorls; aperture whitish with yellowish 
buff submarginal callus within the outer lip. 

Description: Shell ovately fusiform; 2V2 
smooth nuclear whorls; 6 post nuclear whorls; 
first 3 post nuclear whorls with 14 well-defined 
axial costae (see Fig. 3); remaining post nuclear 
whorls with 11 loosely formed axial ribs; suture 
weakly defined; aperture elliptical, more than V2 
the height of the shell; outer lip lacking marginal 
barbs, thickened internally by a submarginal 
lenticular callus; columella with 3 prominent 
adapical plications and 9 thread-like lirations, 
with the most adapically placed lira best 
developed; siphonal fasciole weak, anal sulcus 
shallow; operculum and radula unknown. Color, 
see diagnosis. 

Type locality: off Cabo Rojo, Puerto Rico, 
trawled in 500 ± m., ex-E. Flynn Ford coll., ex- 
Fred L. Leonard coll., 1981. 

Holotype: AMNH no. 213575, from the type 
locality; height = 52 mm, width = 21.2 mm. 
Here illustrated, Figs. 1, 2 and 3. 

Paratype: NMNH no. 820640, R/V John 



30 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 




FIGS. 1-6. Lyria leonardi new species. 1-3, Holotype, AMNH no. 213575; 4-6, Paratype, NMNH no. 820640. 1 and 2 approx- 
imately x lVs; 3, early whorls greatly enlarged; 4-6, x 1. 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 31 



Elliott Pillsbury station P-758 (11° 42.4' N., 
60° 40' W), in 16 m., Golfo de Triste, Venezuela 
(see Petuch, 1981, p. 331, figs. 75-76); fragment 
lacking pre-body whorls, height = 72.00 mm. 
Here illustrated, Figs. 4-6. 

Referred specimen: NMNH no. 87718, U.S. 
Fish Commission station 2120, in 133.5 m, near 
Grenada, Lesser Antilles (see Dall, 1907, p. 
351); fragment lacking much of the body whorl, 
height = 29.3 mm. 

Remarks: The color pattern approaches that 
of L. limata Hoerle and Vokes (1978, pi. 1, figs. 
5a, 5b), but this smaller, more slender Miocene 
species has better developed costae, stronger 
and fewer columellar lirations, and possesses 
barbs on the outer lip. 

Lyria russjenseni new species 
Figures 7 to 15 

Diagnosis: Shell narrowly fusiform, 8V2 
whorls, medium size for genus, attaining 70 + 
mm in height; axial sculpture of 12 to 13 ir- 
regularly formed ribs; color buff-cream with 
small v-markings, spirally banded by broken 
blotches of irregular brown squares below the 
suture, midway and anteriorly on the body 
whorl; bands interrupted by zigzag patterns, 
especially at base of the body whorl; outer lip 
ringed within by a yellowish buff, submarginal 
callus; aperture white. 

Description: Shell slender, fusiform; 2V2 
smooth nuclear whorls; 6 post nuclear whorls; 
axial costae 12 to 13 per whorl, weakly devel- 
oped on 1st and 2nd post nuclear whorls (see 
Fig. 15); obsolete on 3rd and 4th whorls; promi- 
nent on penultimate whorl and body whorl; 
suture distinct, weakly channeled; aperture nar- 
rowly elongate, about V2 the height of the shell; 
interior of outer lip thickened submarginally by 
a lenticular callus in mature specimens, lacking 
marginal barbs; columella with 3 prominent 
adapical plications and 12 to 17 weak lirations 
extending into the aperture, terminating in a 
more prominent lira at the adapical end in 
mature specimens. Siphonal fasciole weak; anal 
sulcus narrow and shallow; operculum and 
radula unknown. Color, see diagnosis. 

Type locality: off La Paguera, Puerto Rico, 
taken in a lobster pot by fisherman, 1978, ex- 
Miguel Carlo, ex-Russell Jensen coll. 

Holotype: AMNH no. 213576, from the type 



locality; height = 65.5 mm, width = 26.2 mm. 
Here illustrated, Figs. 7, 8. 

Paratype A: off Cabo Rojo, Puerto Rico, in a 
fish trap, in approximately 244 m., ex-Miguel 
Carlo, 1983, Harry G. Lee coll.; height = 71.5 
mm, width = 28.8 mm. Here illustrated, Figs. 9, 
10, and 15. 

Paratype B: off Cabo Rojo, Puerto Rico, in a 
fish trap set 8 to 10 miles off shore in approxi- 
mately 300 m., mid-1979, ex-Miguel Carlo, 
Gregory Curry Sr. coll.; height = 39.4 mm, 

width = 17.2 mm. 

Paratype C: AMNH no. 213574, same locality 
as paratype B, ex-Miguel Carlo, 1979, ex- 
Richard Goldberg coll.; height = 26.8 mm, 
width = 13.4 mm. Juvenile specimen, here il- 
lustrated, Figs. 13, 14. 

Paratype D: same locality as paratype B, ex- 
Miguel Carlo; Gregory Curry, Sr. coll.; height = 
57.7 mm (apex incomplete), width = 25.4 mm. 
Here illustrated, Figs. 11, 12. 

Paratype E: off Mayaquez, Puerto Rico, in a 
fish trap, set in 274 mm; ex-Miguel Carlo, 1982, 
Michael Cahill coll.; height = 56 mm, width = 
24 mm. 

Remarks: This species resembles L. beauii 
(Fischer and Bernardi, 1857) in shell morphol- 
ogy, but it differs in having less extended axial 
ribs on the body whorl, and a distinctive color 
pattern. In Lyria leonardi n. sp. the axial ribs 
adjoin the suture, whereas in the present species 
and L. beauii the ribs are poorly developed at 
the suture in mature specimens (Figs. 7-10). 



Acknowledgments 

In addition to Russell H. Jensen and Fred L. 
Leonard, I am indebted to a number of people 
for valuable contributions to this study. The fol- 
lowing generously provided specimens on loan 
and/or contributed pertinent information: Kirk 
Anders, Michael Cahill, Miguel Carlo, Gregory 
Curry, Sr., C. John Finlay, Mary S. Ford, 
Richard Goldberg, Thomas Honker, Harry G. 
Lee, Edward J. Petuch, Joseph Rosewater, 
John K. Tucker, and Thomas R. Waller. My 
AMNH colleagues, Walter Sage, III, Peter J. 
Harries, and Stephanie Crooms kindly provided 
technical assistance, photography, and the word 
processing, respectively. 



32 THE NAUTILUS 



January 30, 1985 



Vol. 99(1) 




FIGS. 7-l. r >. Lyria russjenseni nnr spears. 7 and 8, Holotype, AMNH no. 213576; 9, 10, 15, Paratype A, H. G. Lee coll.; 11 
and 12, Paratype D, G. Curry, Sr. coll.; 13 and 14, Paratype C. AMNH no. 213574. 7-14 approximately x IVs; 15, early whorls 
greatly enlarged. 



Vol. 99(1) 



January 30, 1985 



THE NAUTILUS 33 



LITERATURE CITED 

Abbott, R. T. 1972. Kingdom of the Seashell, New York, 
256 pp. 

1974. American Seashells, The Marine Mollusea 

of the Atlantic and Pacific Coasts of North America, New 
York, 2nd ed., 663 pp., 24 pis., text figs. 

Abbott, R. T. and Dance, S. P. 1982. Compendium of Sea- 
shells, A Color Guide To More Than 4,200 of the World's 
Marine Shells, New York, 411 pp., illus. 

Adams, H. and A. 1853[-1854]. The Genera of Recent Mol- 
lusea; arranged according to their organization. London, 
vol. 1, pp. 1-256, pis. 1-32 [1853]; pp. 257-484, pis. 33-60 
[1854]. 

Angas, G. F. 1865. Descriptions of ten new species of shells, 
chiefly from the Australian Seas, Proc. Zool. Soc. London, 
pt. 1, pp. 55-58, pi. 2. 

Bayer, F. M. 1971. Biological results of the University of 
Miami Deep-Sea Expeditions. 79. New and unusual mol- 
lusks collected by R/V John Elliott Pillsbury and R/V 
Gerda in the tropical western Atlantic. Bull. Mar. Set., 
vol. 21, no. 1, pp. 111-236, 72 figs. 

Clench, W. J. and Turner, R. D. 1967. A new species of 
Lyria (Volutidae) from Hispaniola. The Nautilus, vol. 80, 
no. 3, pp. 83-84, figs. 1-3. 

Dall, W. H. 1907. A review of the American Volutidae. 
Smithsonian Misc. Coll., vol. 48, no. 3, pp. 341-373. 



Dance, S. P. 1969. Rare Shells. Berkeley, 128 pp., 25 pis. 

Fischer, P. and Bernardi, A. C. 1857. Descriptions d'especes 
nouvelles. Jour. ConchyL, vol. 5, no. 3. pp. 292-300, 
pis. 8, 9. 

Hoerle, S. E. and Vokes, E. H. 1978. A review of the 
volutid genera Lyria and Falsilyria (Mollusea: Gastro- 
poda) in the Tertiary of the Western Atlantic. Tulane 
Studies Geol. and Paleont, vol. 14, no. 3, pp. 105-130, 
pis. 1-5. 

Petuch, E. J. 1981. A relict Neogene caenogastropod fauna 
from northern South America. Malacologia, vol. 20, no. 2, 
pp. 307-347, figs. 1-130. 

Pilsbry, H. A. and Olsson, A. A. 1954. Systems of the Voluti- 
dae. Bull. Amer. Paleont., vol. 35. no. 154, pp. 1-37, 
pis. 1-4. 

Pointier, J. P. 1981. Les Lyria des Caraibes. Xenophora 
(Bull. Club Francais Collectionneurs de Coquillages), no. 
3, May, pp. 13-15, 4 text figs., 2 pis. 

Tryon, G. W., Jr. 1882. Family Volutidae, Manual of 
Conchology, ser. 1, vol. 4, pp. 73-105, pis. 22-31, Phila- 
delphia. 

Weaver, C. S. and duPont, J. E. 1970. The Living Volutes, 
A Monograph of the Recent Volutidae of the World. 
Delaware Mus. Nat. Hist. Monogr. Ser. no. 1, 375 pp., 
78 pis.-, 43 text figs. 



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W oods Hfrt», M33S. 
CONTENTS 



THE 

NAUTILUS 

Volume 99, numbers 2-3 - April 29, 1985 

ISSN 0028-1344 



William G. Lyons 

Chaetopleura staphylophera (Polyplaeophora: Chaetopleuridae), a New Species 

from the Southeastern United States and Bahamas 35 



Jose Henrique N. Leal and Arnaldo C. dos Santos Coelho 
Arenejlexispina, a New Species (Gastropoda: Liotiidae) from Off Eastern Brazil 45 

Gary L. Pace and Ernest J. Szuch 

An Exceptional Stream Population of the Banded Applesnail, 

Viviparus georgianus, in Michigan 48 

John W. Ropes 

Modern Methods Used to Age Oceanic Bivalves 53 

Anthony D'Attilio and Barbara W. Myers 

Two New Species oiFavartia from the West Pacific Ocean (Gastropoda: Muricidae) 58 

Paul S. Mikkelsen 

A Rapid Method for Slide Mounting of Minute Radulae, 

with a Bibliography of Radula Mounting Techniques 62 



Scott E. Belanger, Jerry L. Farris, Donald S. Cherry, and John Cairns, Jr. 

Sediment Preference of the Freshwater Asiatic Clam, Corbicvlafluminea. . . . 



.66 



C. John Finlay 

A West Indian Columbellid New to the Genus Steironepion 73 

Neil C. Hulings 

Activity Patterns and Homing in Two Intertidal Limpets, Jordan Gulf of Aqaba 75 

Fred G. Thompson and Emilye L. Huck 

The Land Snail Family Hydrocenidae in Vanuatu (New Hebrides Islands), 

and Comments on Other Pacific Island Species 81 

Ralph W. Taylor 

Comments on the Distribution of Freshwater Mussels (Unionacea) of the 

Potomac River Headwaters in West Virginia 84 

J. Gibson-Smith and W. Gibson-Smith 

A Second Melampid (Pulmonata: Basommatophora) from 

the Early Miocene of Venezuela 87 



Deaths iv, 80 Meetings 44, 80 



in 



STATEMENT OF OWNERSHIP, MANAGEMENT AND CIRCULA- 
TION (Required by) Act of October 23, 1962: Section 4396. Title 
39. United States Code, and postal regulation 132-622. 

1 Title of publication: THE NAUTILUS. 

2. Date of filing: October 17, 1984. 

3. Frequency of Issue: Quarterly (4 per year). 

4. Location of known office of publication: 2208 South 
Colonial Dr., Melbourne, FL 32901. 

5. Location of Headquarters of General Business Offices of 
the Publishers: 2208 South Colonial Dr., Melbourne, FL 
32901 

6. Names and addresses of publisher, editor, and manag- 
ing editor: Publisher, American Malacologists, Inc., P.O. 
Box 2255, Melbourne, FL 32901. Editor, R. Tucker Abbott, 
P.O. Box 2255, Melbourne, FL 32901. Business Manager, 
Mrs. Cecelia W. Abbott, P.O. Box 2255, Melbourne, FL 
32901. 

7. Owner: American Malacologists, Inc., P.O. Box 2255, 
Melbourne, FL 32902. 

8. Known bondholders, mortgages, and other security 
holders owning or holding 1 percent or more of total 



amount of bonds, mortgages or other securities: none 
Extend and Nature of Circulation: 



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and back start subscription copies 

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press run shown in A. 



I certify that the statements made by me above are correct and 

complete. 

(signed) R. Tucker Abbott, Editor 



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Faye B. Howard, 1907 - 1984 
The Santa Barbara Museum of Natural His- 
tory recently lost one of the driving forces 
behind the development of malacology in the 
Department of Invertebrate Zoology. Delia 
Faye Ballou was born at home in Grumpier, 
North Carolina on February 15, 1907. At the 
age of ten her family moved to California. She 
attended Fullerton City College and the Univer- 
sity of California, Berkeley where she was intro- 
duced to shells by her neighbor, John Jones. 
Beginning in 1932 until shortly before her 
death, Faye engaged in private research in con- 
chology. In 1961 she was appointed as a 
Research Associate in Conchology at the 
Museum. From 1961 to 1968 she 'personally 
funded the position of Assistant in Conchology 
at the Museum. During the same period Faye 
organized, financed and led six major expedi- 
tions to West Mexico to study and collect mol- 



lusks. With the impetus of Faye's enthusiasm 
and support, the Santa Barbara Malacological 
Society was founded in 1962. She served on the 
Editorial Board of the Society's publication, the 
Tabulntu, from 1967 to 1974. Faye was a 
member of the Conchological Club of Southern 
California for 54 years and was also a member of 
the Hawaiian Malacological Society. She 
authored a total of 22 publications on mollusks 
and famous malacologists. She described two 
new species of marine gastropods, and had four 
new species and one new subspecies named in 
her honor. She died December 14, 1984. Faye's 
dream of establishing a major center for the 
study of mollusks in Santa Barbara will become 
a reality, supported by her large collection and a 
bequest which she leaves to the museum. This 
legacy will forever preserve her memory but will 
never fill the void she leaves behind. 

- F. G. Hochberg 



ir 



THE NAUTILUS - ITS 99th YEAR 
(an editorial) 

77/r Nautilus had its beginnings in Philadelphia on July 1, 
1886. That means we shall be celebrating our KMlth anniversary 
next year, in 1986. We began as The Conchologist's Exchange, 
with W. D. Averell as editor. When Henry A. Pilsbry took over 
as the chief editor in 1889, the name was changed at the third 
volume to The Nautilus. Since then, in the span of 96 years, 
there have been only three chief editors- Henry A. Pilsbry, H. 
Burrington Baker and myself. 

It is time for an editorial. Its purpose is to invite our friends 
and subscribers, both professional malacologists and private 
amateur collectors, to participate in our celebration of 100 years 
of service to the malacological community. We will briefly 
review the history of the journal, but our main theme will be a 
memorial tribute to the late William J. Clench and to his former 
student, the late Joseph Rosewater. The 100th volume will 
largely consist of scientific articles on mollusks, many by Bill 
Clench's students, that acknowledge his help or that may name a 
new taxon in his honor. Additionally, we hope to do the same for 
Joe Rosewater. Personal reminiscences about either malacolo- 
gist will be most welcome. 

Although The Nautilus is independent of any university or 
museum, it has existed only because of the support from in- 
dividual malacologists and private collectors. During my -7 
years as an editor, I have been most appreciative of this support. 
and I hope that the next editor, who ever he or she may be, will 
carry on in the same cooperative spirit. 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 35 



CHAETOPLEURA STAPHYLOPHERA (POLYPLACOPHORA: 
CHAETOPLEURIDAE), A NEW SPECIES FROM THE 
SOUTHEASTERN UNITED STATES AND BAHAMAS 

William G. Lyons 

Florida Department of Natural Resources 
Bureau of Marine Research 
St. Petersburg, FL 33701 

ABSTRACT 

Chaetopleura staphylophera n. sp.,from off North Carolina, the Bahamas, and 
both Florida coasts, differs from other western Atlantic Chaetopleura by posses- 
sion of considerably larger, nonaligned pustules on end valves and lateral areas of 
intermediate valves, and from the west American C. gemma in that pustules of 
that species are aligned in radial rows. Relegation o/Calloplax Thiele, 1909. to 
synonymy with Chaetopleura Shuttleworth, 1853. is recommended. 



Investigations of continental shelf fauna of 
relatively deep waters off Florida and adjacent 
areas have revealed a previously unknown 
species of the genus Chaetopleura Shuttleworth, 
1853, which is here described. Questions regard- 
ing generic placement of this and another spe- 
cies prompted review of characters of Chaeto- 
pleura and of the genus Calloptax Thiele, 1909. 

Most specimens examined during this study 
were collected during the Hourglass Cruises off 
central west Florida (Joyce and Williams, 1969), 
a survey of rock shrimp off northeast Florida 
(Kennedy et al., 1977), and a study of the fauna 
of Oculina reefs off central east Florida (Avent 
et al., 1977; Reed et al., 1982). The first two pro- 
grams were conducted by the Florida Depart- 
ment of Natural Resources Bureau of Marine 
Research utilizing the R/V Hernan Cortez, and 
the third was conducted by Harbor Branch 
Foundation utilizing the submersible Johnson- 
Sea-Link (JSL). Specimens are housed in the 
U.S. National Museum of Natural History, 
Smithsonian Institution (USNM), Washington, 
DC; the Academy of Natural Sciences of Phila- 
delphia (ANSP), Pennsylvania; the American 
Museum of Natural History (AMNH), New 
York; the Brevard Museum, Inc. (BMI), Cocoa, 
Florida; the British Museum (Natural History) 
(BMNH), London; the California Academy of 
Sciences (CAS), San Francisco; the Harbor 
Branch Foundation (HBF; museum prefix 
IRCZM), Ft. Pierce, Florida; the University of 
North Carolina Marine Science Institute (UNC), 



Morehead City; and the Florida Department of 
Natural Resources Bureau of Marine Research 
(FDNR; museum prefix FSBC I), St. Peters- 
burg. Because nearly all specimens were curled 
to some extent, measurements of total length 
are to the nearest 0.5 mm; individual valve- 
lengths are measured at the midline. 

Chaetopleura staphylophera, new species 

(Figs. 1-14. li.s) 

ICalloplax janeirensis: Porter. 1974, p. 302 [mm C. janei- 

rensis (Cray, 1828)]. 
Chaetopleura sp. Lyons, 1982, p. 39. 

Holotype: Length 15.5 mm; Hourglass Station 
M; 26°24'N, 83°43'W, approximately 92 nmi 
west of Sanibel Island Light, Florida west coast; 
73 m depth; 12 April 1966; USNM 842109. 

Other material: FLORIDA: 1 paratype, 15.0 
mm; Hourglass Station M; 12 April 1966; FSBC 
I 31757.- 1 paratype, 17.0 mm; same; 13 
November 1966; FSBC I 31759.- 1 paratype, 
11.5 mm; Hourglass Station D; 27°37'N, 
83°58'W, approximately 65 nmi west of Egmont 
Key; 55 m; 4 April 1967; FSBC I 31758.- 1 
paratype, dried, curled; Eolis Station 104; off 
Fowey Light; 91 m; J. B. Henderson, coll.; 
USNM 454682.- 1 paratype, 21.0 mm; 
27°13.1'N, 79°58.7'W, 9 nmi ENE of St. Lucie 
Inlet; 64 m; 14 April 1973; FSBC I 31760.- 2 
paratypes, 11.0, 15.0 mm; JSL Station 2122A; 
27°32.8'N, 79°58.8'W, east of Ft. Pierce; 77.4 
m; 20 September 1976; IRCZM 61:060. - 2 para- 
types, 6.0, 8.5 mm; JSL Station 2125A; same 



36 THE NAUTILUS 



April 29, L985 



Vol. 99(2-3) 






r* 



Jf 




FIGS. 1-8. 1-6, Chaetopleura staphylophera n. sp., paratype, 15.0 mm; west of Sanibel Island, Florida, 73 m; FSBC 1 31757: 1. 
valve I; 2, valve IV; 3, valve VIII; 4. valve II; 5, valve VIII. lateral view (all x 15); 6, girdle spicule ( x 220); 7, ' ' xtapkylnphem, 
paratype, 16.0 mm; 23. f> nmi east of Port Canaveral, Florida, 73 m; FSBC 1 31761; dorsal girdle scales i ■ 515); 8. same; ven 
tral girdle scales ( x 550). 



coordinates; 77.7 m; 21 September 1976; 
IRCZM 61:061. - 4 paratypes, 1.5-8.5 mm; JSL 
Station 2160A; same coordinates; 73.8 m; 2 
February 1977; IRCZM 61:062.- 1 paratype, 
7.0 mm; JSL Station 2163A; same coordinates; 
80 m; 7 February 1977; IRCZM 61:063.- 1 
paratype, 1.8 mm; JSL Station 2163B; same 
coordinates, depth, and date; IRCZM 61:064.- 
1 paratype, 16.0 mm; [?] 28°02'N, 80°26'W, 8 
nmi east of Grant; is m; 6 June 1978; BMI 
1143.- 2 paratypes, 9.0, 10.0 mm; 28°02.8'N, 
79 r.s.o'W. 31.5 nmi SF of Port Canaveral; 73 
m; 22 May 1973; ANSP A-10629.- 1 paratype, 
12.0 mm; 28°10'N, 80°03'W, 30 nmi ENE of 
Melbourne; 53 m; September 1981; AMNH 
70. - 2 paratypes, 6.5, 16.0 mm; 28°18.9'N, 
79 9 I'W, 23.5 nmi east of Port Canaveral; 73 



m; 19 June 1973; FSBC I 31761.- 1 paratype, 
13.5 mm; 28°35'N, 80°07'W, 24 nmi ENE of 
Cape Canaveral; 61 m; July 1982; BM(NH) 
1985007.- 1 paratype, 9.5 mm; 28°37.1'N, 
80°04.8'W, 25 nmi FNF of Cape Canaveral: 64 
m; 14 August 1973; CAS 056545.- 1 paratype, 
18.0 mm; 28°41'-40'N, 80°03'W, 28 mi ENE of 
Cape Canaveral; 86-91 m; 23 April 1983; FSB< ' I 
30775.- 1 paratype, 13.0 mm; 30 00'N, 
80°15'W. 54 nmi FNF of St. Augustine; 
73.1-82.2 m; 24 June 1982; FSBC I 30774. 
NORTH CAROLINA: 1 paratype. 14.5 nun; 
Eastward Station 480; 34'12'N, 76' 05.9'W, SE 
,>( Cape Lockout; 73-107 m; 18 March 1969; 
UNC 4302.1- GRAND BAHAMA ISLAND: 1 
tail valve (viii). 7.3 nun wide. 4.2 mm long; Gold 
Rock; 24.1 m; J. N. Worsfold, coll.; July 1981; 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 37 



FSBC I 31762. - 1 tail valve (viii), 7.0 mm wide, 
3.8 mm long; Tamarind Beach Reef; 46.8 m; 
Worsfold collection. - 1 intermediate valve, 7.2 
mm wide, 3.1 mm long at jugum; Gold Rock; 
26.2 m; Worsfold collection.- 1 intermediate 
valve, 9.9 mm wide, 4.5 mm long at jugum; 
Indian Cay; 23.0 m; Worsfold collection. 

Description: Largest entire specimen 21.0 
mm long, 9.5 mm wide, including girdle. Some 
paratypes bright orange; holotype and other 
paratypes yellow or beige with white stripe on 
jugum; stripe sometimes overlain with orange, 
anteriorly directed, slender triangle; or, in addi- 
tion, with dark brown in central areas of valves 
ii, iv, v, vii, and viii. Tegmentum ornamented 
with rounded, large pustules (to 300 \xm dia- 
meter) and linearly aligned, usually small (to 150 
\xm diameter) pustules. Width of tegmentum of 
valves of undissected holotype: i = 3 . 6 ; ii = 4.1; 
iii = 4.5; iv=4.6; v=4.8; vi = 4.9; vii = 4.5; viii = 
3.6 mm. Head valve (i) ornamentation beginning 
as radial rows of 3 or 4 small pustules at apex, 
thereafter losing alignment but closely situated, 
increasing in size toward margin, resulting in 
vaguely concentric arcs of pustules of similar 
size. Lateral areas of intermediate valves (ii-vii) 
with about 30-50 large pustules, seldom if ever 
connected, those at anterior margins aligned in 
transverse rows, others scattered, all closely 
packed, increasing in size toward anterolateral 
corners; central areas with as many as 19 or 20 
subparallel, occasionally converging, longitu- 
dinal rows of small pustules (8-9 rows on holo- 
type); pustules of rows increasing in size and 
decreasing in numbers toward lateral margins; 
as many as 20 small pustules in rows near 
jugum; rows usually continuing over jugum of 
valves ii and vii, sometimes absent or inter- 
rupted at jugum of valves iii-vi; posterior edges 
of intermediate valves straight in larger speci- 
mens, slightly beaked in smaller specimens, all 
slightly peaked (subcarinate) at center. Tail 
valve (viii) with mucro slightly elevated, a little 
anterior of center, thereafter dropping away 
concavely for a short distance and then sloping 
gently to posterior margin; jugum and central 
areas with parallel rows of small pustules; re- 
mainder of valve with large, densely packed 
pustules arranged in concentric rows of pustules 
of similar size, largest at margin. 

Articulamentum white, with light brown or 



orange hues evident through strongly excavate 
surfaces beneath lateral areas, somewhat less 
evident beneath central areas, occasionally with 
an orange, longitudinal stripe beneath jugum. 
Insertion teeth well defined, relatively sharp, 
thickened near slit; slit formula 11-1-8. Sutural 
laminae relatively short, broadly rounded ante- 
riorly; sinus well defined; on valve viii of 16.0 
mm specimen, width of sinus 0.9 mm, width of 
sutural laminae 2.4 mm; ratio (relative width of 
sinus) 0.375. Eaves solid. 

Girdle upper surface paved with small (about 
70-75 x 20-35 ^m), ovoid, elongate scales, coarse- 
ly striated toward sometimes pointed distal tips, 
interspersed with a few glassy spicules up to 350 
urn long; girdle outer margin fringed with glassy 
spicules of two types, the first slender, blade- 
like (30x210 fmi), the other very slender and 
small (8-10x55-80 \xm); undersurface paved with 
rectangular, transparent scales about 25 x 
50-100 jmi, each bearing an outer edge pro- 
tuberance that articulates with inner edge con- 
cavity of adjacent scale; girdle bridges packed 
with slender, blade-like spicules (10 x 1 15 j^m). 

Radula of 16.0 mm specimen 5.0 mm long 
(31% of total specimen length), with 48 rows of 
mature teeth; median tooth broadly rectangu- 
lar, about 90 \im wide at anterior blade; major 
lateral teeth with tricuspid head 120 ytm long, 80 
^m wide. 

Variation: The 27 intact specimens range in 
length between 1.5 and approximately 21.0 mm. 
No pustules are present on two specimens 1.5 
and 1.8 mm in length, but a 2.2 mm specimen 
(IRCZM 61:062) has single large pustules at 
anterolateral corners of each intermediate 
valve, indicating that tegmental ornamentation 
may begin at about that size. Thereafter, large 
pustules of all valves apparently increase in size 
and number with increasing size of the animal. 
The largest specimen (21.0 mm; FSBC I 31760; 
Fig. 14) is severely eroded on all valves, par- 
ticularly at the junctions of lateral and central 
areas of the intermediate valves. The rows of 
small pustules of central areas extend over the 
jugum of all valves except iv, which remains 
smooth on the posterior half; indications of 
19-20 pustule rows are present on some valves. 
In lateral areas of the 21.0 mm specimen, 
largest pustules tend to occur near the middle, 
and pustules nearest the girdle are somewhat 



38 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 




FIGS. 9-12. Single valves of Chaetopleura staphylophera n. 

sp. from sediments, Grand Bahama Island (all x 3.5): 9, 
valve VIII; Gold Rock, 24.4 m; FSBC I 31762; 10, valve VIII, 
Tamarind Beach reef, 4(1.8 in; 11, intermediate valve; Gold 
Rock, 26.2 m; 12, intermediate valve; Indian Cay, 23.0 m. 
[Figured specimens ld-12 in Worsfold collection]. 

smaller and arranged in rough, concentric arcs, 
giving the impression of less energetic growth 
with advanced age. 

The Bahamian specimens consist only of sin- 
gle valves (Figs. 9-12), but their tegmental 
pustular arrangements are similar to those of 
specimens from North Carolina and Florida. If, 
as seems likely, the Bahamian specimens repre- 
sent the new species, this may indicate that the 
species attains greater size than exhibited by 



the largest (21.0 mm) entire specimen; width of 
the tegmentum of valve viii of that specimen is 
only 5.2 mm, whereas that of the largest Baha- 
mian specimen is 7.3 mm. 

Distribution: Intact specimens of Chaeto- 
pleura staphylophera were examined from off 
Tampa Bay and Sanibel Island, Florida west 
coast; off Fowey Light near Miami; offshore of 
St. Lucie Inlet northward to St. Augustine 
along the Florida east coast; and southeast of 
Cape Lookout, North Carolina. Because all 
other Florida specimens were taken from 
depths of 53-91 m, the single record from 18 m 
(BMI 1143) is questioned. The North Carolina 
collection is from "240-350 ft" ( = 73-107 m), so 
that specimen may have occurred within the 
depth range of the Florida material or in slightly 
greater depths. All Bahamian specimens are 
from off the southwest coast of Grand Bahama 
Island and consist only of single valves collected 
by divers from sediments near reefs in 23-47 m 
depths, somewhat shallower than the continen- 
tal collections. 

Etymology: The specific name staphylophera, 
from the Greek staphyle (a bunch or cluster of 
grapes) and phero (to bear or carry), refers to 
the distinctive clusters of large, grape-like 
pustules on lateral areas of intermediate valves. 

Remarks: Porter (1974: p. 302) listed the 




13 



14 



15 



16 



17 



FIGS. 13 17. 13, Chaetopleura staphylophera n. sp.. holotype, 15.5 mm; west of Sanibel Island. Florida, 73m; USNM 842109; 

14, C iaphylophera, paratype, 21.0 mm; 9 nmi ENE of St. Lucie Inlet, Florida, 64 m; FSBC I 3176(1; 15, Chaetopleura 

Ua (Say), 12. 1 mm; cast of Hutchinson Island, Florida, 91.5 m; FSB< ' I -".0767, 16. "' 'alloplax" janeirensis (Gray), 18.0 

mm; Sand Ke reef, Florida, 1 m; FSBC I 31765; 17. "C "janeirensis, 16.0 mm; Riode Janeiro, Brazil, shallow; FSBC I 31768. 



Vol. 99(2-3) 



April 29. 1985 



THE NAUTILUS 39 



North Carolina specimen as ICalloplax janeiren- 
.s/.s, and Lyons (1982: p. 39) mentioned an un- 
described species of Chaetopleura from the 
Bahamas. Both reports were based upon speci- 
mens used in this study and which are herein 
described. 

The new species differs from Cliactuplcura 
apiculata (Say, 1834), the only previously 
known Chaetopleura species from the eastern 
and southern United States, by possession of 
much larger, more densely arrayed pustules on 
the end valves and on lateral areas of inter- 
mediate valves (Figs. 18-20). Additionally, the 
major lateral tooth of the radula of C. apiculata 
is bicuspid (Fig. 29), whereas that of the new 
species is tricuspid (Fig. 28). In areas where the 
ranges of the two species overlap latitudinally, 
C. apiculata usually (bul not always) occupies 
shallower depths than does < '. staphylophera. 
Other western Atlantic species of Chaetopleura 
are known only from the southern Caribbean or 
further south. These include C. candisata 
Shuttleworth, 1856 ( = C apiculata. fide Kaas, 
1972; Kaas and Van Belle, 1980;' Ferreira, 
1983a), from Cuadeloupe, and C. angulata 
(Spengler, 1797), C. isabellei (d'Orbigny, 1841), 



and <'. spiiiuliisii (Cray, 1828), all from Brazil or 
southward to Patagonia. Published descriptions 
of the last three species indicate that all possess 
tegmental pustules considerably smaller and 
more widely spaced than those of the new 
species. Chaetopleura carrua Righi, 1970, en- 
tirely lacks pustules on end valves and lateral 
areas of intermediate valves. Instead, Chaeto- 
pleura staphylophera demonstrates a close rela- 
tionship to Chaetopleura gemma Dall, 1879, a 
west American species which occurs from Van- 
couver Island, Canada, to Magdalena Bay, Baja, 
California (Burghardt and Burghardt, 1969; 
Putnam, 1980). That species lives in depths of 
10-40 fms (18-73 m) or more according to Clark 
(1982), but Ferreira (1983a) reports the bathy- 
metric range as 0-22 m; the reason for this dis- 
crepancy is unknown. Like the new species, the 
major lateral tooth of the radula of C. gemma is 
tricuspid (Dall, 1879: 296, pi. 1, fig. 9). Tegmen- 
tum color, size and shape of pustules, and slit 
formula (9-12/1/7-8) of C. gemma are also similar 
to those of < '. staplnjlojthcra, but pustules of the 
lateral areas of C. gemma are arranged in 4-7 
radiating rows (Pilsbry, 1892; Ferreira, 1983a), 
whereas those of C. staphylophera are not 




FIGS. 18-21. ( 'haetvpleura a pi ruin In (Say). 11.0 mm; Anclote Key, 

valve VIII (all x 111); 21, dorsal girdle scales ( x 600). 



Fieri. la. :■; m; FSBC 1 .",17li4: 18. valve I; 19, valve IV; 20. 



in THE NA1TI1J/S 



April 29, 1985 



Vol. 99 (2-3) 



aligned except at anterior margins. Likewise, 
there are LO-15 longitudinal rows of pustules on 
centra] areas of ( '. gemma (fide Ferreira, 1983a), 
whereas C. staphylophera lias as many as 20 
such rows. The tail valve of C. gemma illustrated 
by Pilsbry (1892: pi. 13, fig. 74) also differs from 
that of C. staphylophera, being ornamented with 
many radial rows of numerous beads rather 
than the essentially nonaligned pustules of the 
new species. 

Clim tujih/n-ii stiijihi/lD/ihirn is distinguished 
from Calloplax janeirensis [3.\s,o = Chi I on smccr- 
binna Reeve, 1847, formerly considered a 
species of Chaetopleura, fide Ferreira (1979)], 
the only other species of Chaetopleuridae in 
Florida and the northern Caribbean, by posses- 
sion in the latter of strong radial ribs (Fig. 16) or 
rows of loosely coalesced pustules (Figs. 17, 
22-24) instead of unaligned pustules on end 
valves and lateral areas of intermediate valves. 
However, the new species resembles C. janei- 
rensis in the size and shape of pustules, in the 




30 

FIGS. 28-30. Major lateral radular teeth: 28. 
Chaetopleura staphylophera n. sp. (> 450); 29. 
Chaetopleura apiculata (x 4(iii); .'{0, "Calloplax" 
janeirensis ( ■ 500). 



TK^b, 



JM*^ 




FIGS. ■i'l-Ti. 22-25, "Calloplax" janeirensis (Cray), L0.5 
mm; Dry Tortugas, Florida. 1 m; FSBC I 31767: 22, valve I; 
2:t, valve tV: 21. valve VIII (all x 12); 25, dorsal girdle 

I • 300); 26, "C. "janeirensis, L5.5mm;Kej Vaca, 1 m; 

i 31766; girdle ipicule < ■ 200); 27, "C " jam irensis, 
ii \ aca, Florida, 1 m; FSBC I 31766; ventral 

girdle scale i • 300). 



pel 'lily surface of the interpustular tegmentum 
of head and tail valves (Figs. 1, 3, 22, 24). and in 
morphology of scales (Figs. 7, 8, 25, 26) and 
scattered glassy spicules (Figs. 6. 27) of the dor- 
sal surface of the girdle. Both species also 
possess radulae with tricuspid major lateral 
teeth, but cusps are much longer and more acute 
on teeth of C. staphylophera than are those of ( '. 
janeirensis (Fig. 30). 

Ferreira' s statement (1983a: p. 220) that 
Chaetopleura gemma "poses no diagnostic prob- 
lems [as a species of Chaetopleura] given its very 
different characteristics in shape, size and sculp- 
ture [including "tubercular ridges" on lateral 
areas]" is perplexing because that species, like 
C. staphylophera, also strongly resembles 
Calloplax janeirensis. Efforts to clarify the 
generic affinities of these species prompted a 
review of recent treatments of both genera. 

Thiele (1909) erected Calloplax to contain 
Cliihm junei rensis Gray, 1828. which occurs 
from Brazil to south Florida. Assigned to Chae- 
topleura Shuttleworth, 1853, by several authors 
during the latter half of the nineteenth century, 
( '. janeirensis was separated from that genus by 
Thiele because the pustules of the head. tail, and 
lateral areas of intermediate valves are much 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 41 



larger than those of species of Chaetopleura and 
are usually coalesced to form prominent ribs. 
Calloplax was placed in Chaetopleuridae by 
Thiele (1929) where it remained until recently. 
No additional species were described until A. G. 
Smith and Ferreira (1977) reassigned the ende- 
mic Galapagos species Callistochiton duncanus 
Dall, 1919, to Calloplax, thereby establishing 
the presence of the genus in the eastern Pacific; 
Smith and Ferreira concurrently reassigned 
Calloplax to Callistoplacidae. Soon thereafter, 
Ferriera (1978) transferred a Chilean species, 
Callistochiton viviparus Plate, 1899, to 
Calloplax, redescribed C. janeirensis and C. 
duncanus, reviewed synonymies of all three and 
retained Calloplax in Callistoplacidae. More 
recently, Ferreira (1982) described a third east- 
ern Pacific species, Calloplax hanselmani, from 
Peru and the Galapagos Islands northward to 
Mexico. In that paper, Ferreira expressed 
uncertainty regarding the taxonomic position of 
Calloplax and, after assessing similarities be- 
tween Calloplax, Chaetopleura and Callistochi- 
ton, concluded that Calloplax should be returned 
to Chaetopleuridae. 

Although Ferreira (1978, 1982) twice provided 
diagnostic comments for Calloplax and most 
recently (1983a) provided similar comments for 
Chaetopleura, he did not define characters 



separating species of the two genera. Difficulty 
in identifying differences between the genera 
has been complicated by unequal application of 
diagnostic characters. Thus, Ferreira's (1982) 
diagnosis of Calloplax mentions overall shape, 
tegmental ornamentation, location and config- 
uration of the mucro, and girdle ornamentation, 
whereas his (1983a) diagnosis of Chaetopleura 
includes comments on size, tegmental ornamen- 
tation, insertion plates, slits of intermediate 
valves, eaves, girdle ornamentation, gills, and 
radular morphology. To allow more equitable 
comparison of the two genera, information on 
the above characters and on girdle bridges (see 
Ferreira, 1983a) was compiled from species 
descriptions as well as diagnoses in each of 
Ferreira's three papers (Table 1). 

Information in Table 1 reveals that although 
some species of Chaetopleura have features 
(e.g., small pustules on head and tail valves and 
lateral areas of intermediate valves; girdle 
hairs; bicuspid major lateral tooth) not found on 
any species of Calloplax, all features except the 
radial ribs of some species of Calloplax are fully 
contained within the range of characters of 
Chaetopleura. In fact, Calloplax hanselmani has 
radial rows of unconnected pustules, not ribs, in 
areas where ribs customarily occur on species 
assigned to Calloplax. and even ribs of C. janei- 



TABLE 1. Diagnostic Characters in Recent Reviews 1 of Chaetopleura and Callopla 



Character 



( 'lini-tnpli'iirn 



< 'alloplax 



Size 

Shape 

Tegmentum 



Insertion piates 

Intermediate valves 
Eaves 

Mucro 



(lirdle 



( rirdle bridges 
Gills 

Radula 



Small to large (8-60 mm length). 

Ovate (length/width ratio 1.4-1.8:1). 

Larger pustules in quincunx or radial rows in 
end valves and lateral areas of intermediate 
valves; smaller pustules in longitudinal 
rows or coalesced in riblets in central 
areas. 

With "rather sharp" teeth. 



Uni-slit. 

Solid. 

Posterior, central or slightly anterior 

concave or convex postmucro, with 

without additional false mucro. 
With minute, simple, oval to spiculoil 

interspersed with glassy, hyaline s] 

some species with horny hairs. 
With or without spicular elements. 
Holobranchial, abanal. 
Median tooth wide, subquadrangular; major 

lateral teeth tricuspid or bicuspid. 



with 



1 scales, 

licules; 



Small to medium (13-21 mm length). 

Elongate (length/width ratio ca. 2:1). 

Strong radial ribs or rows of pustules in end 
valves and lateral areas of intermediate 
valves; longitudinal, often granulose 
riblets in central areas. 

With "CallistockitonAike" to "relatively 

sharp" teeth. 
Uni-slit. 

Solid. 

Centra] or slightly anterior, with convex 
postmucro. 

With spicules (not hairs) interspersed amidst 
small, ovoid, closely parked, coarsely 
striated scales. 

With or without spicular elements. 

| Not defined]. 

Median tooth wide, subquadrangular; major 
lateral teeth tricuspid. 



'From Ferreira (1978, 1982, 1983a) 

2 Ranges based on largest reported sizes of various species. 



42 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



rensis occur as rows of loosely connected pus- 
tules in some specimens from Florida (Figs. 22- 
24) and Rio de Janeiro (Fig. 17), the type-locality 
of the type-species of Calloplax. This seems to 
eliminate the value of radial ribs as a generic 
character and requires the conclusion that 
( 'ullopliu: is a junior synonj m of ( 'haetopleura. 
A brief review based upon morphological in- 
formation available in published literature 
(Pilsbry, 1892; Thiele, 1893; Plate, 1899; Righi, 
1967, 1970; Bullock, 1972; Ferreira, 1978, 1982, 
1983a) suggests that most of the 22 New World 
species of Chaetopleuridae are separable into 
two groups as defined by Pilsbry (1892: p. 28): 
"(1) typical forms, rather large, and having very 
delicate sculpture; and (2) group of C. gemma, 
having the lateral areas strongly raised and 
coarsely sculptured." These groups approximate 
those previously allotted to Chaetopleura and 
Calloplax, but some "intermediate" species do 
not conform fully to either group (Table 2). 



The first group is comprised of species with 
bicuspid lateral radular teeth, corneous girdle 
hairs in addition to scales and glassy spicules, 
and small tegmental pustules widely scattered 
or separated in rows. This group includes Chae- 
topleura angulata (Spengler, 1797), C. apinilatu 
(Say, 1834), C. asperrima (Gould, 1852), C. hen- 
nahi (Gray, 1828), C. iquiquensis (Plate, 1899) 
and C. peruviana (Lamarck, 1819). Radulae of 
C. benaventei Plate, 1899, and C. fernandensis 
Plate, 1899, have not been described, but these 
species closely resemble C. peruviana and C. 
i/ptiiptrttsis, respectively, in other characters 
(see Ferreira, 1983a: p. 221), so they also may 
belong to this group. Ferreira (1983a) implied 
that C. unilineata Leloup, 1954, lacks girdle 
hairs, but a photograph (his fig. 28) seems to 
show scattered hairs on the girdle of that 
species; if present, they would place C. unili- 
neata in this group as well. I am unable to ascer- 
tain whether C. isabellei (d'Orbigny, 1841) or C. 



TABLE 2. Groupings of New World Chaetopleura species, based upon features of the girdle, radula and tegmentum. 





•s. 










•f. 






w 


y: 


■s. 




-- 










V 






QJ 


0; 






— 










3 






3 


3 


3 Ja 














— 






+j 


~ 






cfl 




7i _r- 






7 


rt J3 




Tfi = 


w 


[fl u 




3 










~ 






= u 


- 




S]iccn'.- 


~3 




-c 5 
is 3 


■s. 

"5s 

— 




— 


5 — 


'S 


Ifl 

ta '-5 
c S 


— 
"5 
- 


— "o 

C IN 




v 




"P. ■= 




c 


Q> 


"js S- 


0) ^ 


0) B 


V 


Q) 




E 

& 




S £ 

J 3 


5 


0> 

0) 

a. 




Z 3 

j B 


— E 
~ V 




E - 
he be 
^ fa 

■- - 


E ~ 


' ' carrua 


X 




X 


7 
















C. angulata 






X 


X 




X 












( ' apiculata 






X 


X 




X 












( '. asperrima 






X 


X 




X 












< '. hennahi 






X 


X 




X 












< ', iquiquensis 






X 


X 




X 












' ' peruviana 






X 


X 




X 












< ' I,, naventei 






7 


X 




X 












i ' fernandensis 






7 


1 

X 




X 












C isabellei 






X 


? 




X 












C. spinulosa 






X 


7 




X 












i ' unilineata 






X 


7 




X 












i ' scabricula 








X 




X 


X 










C lanuginosa 












\ 


X 


X 








I ' roddae 














X 


X 


X 






< '. skyana 














X 


X 


X 






i ' gemma 














X 


X 




X 




i ' hanselmani 














X 


\ 




X 




i ' jam - 














X 


X 




X 




• ilopfu ra 














X 


X 




X 




< '. duncana 














X 


X 






X 


ipara 














X 


X 






X 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILI'S 43 



spinulosa (Gray, 1828) have girdle hairs; if so, 
those species also belong here. The type-speeies 
of Chaetopleura is Chiton peruvianus Lamarck 
[subsequent designation, Dall (1879)], so species 
in this group would best typify Chaetopleura s.s. 

Although central areas of its intermediate 
valves bear rows of tiny, coalesced pustules, 
Chaetopleura cumin Righi, 1970, entirely lacks 
tegmental pustules on head and tail valves and 
on lateral areas of intermediate valves. In this 
regard, C. carrua resembles C. angulata. a 
species in which tegmental pustules may be 
nearly obsolete. Its bicuspid radula appears to 
ally C. carrua with the above group. 

Chaetopleura scabricula (Sowerby, 1832) also 
resembles species in the above group by having 
small tegmental pustules and distinct girdle 
hairs but differs by having tricuspid lateral 
teeth. Chaetopleura, lanuginosa (Dall, 1879) 
likewise resembles species in the first group by 
having small, scattered tubercles but lacks 
girdle hairs and has tricuspid lateral teeth. 

Chaetopleura roddae Ferreira, 1983, and C. 
shyana Ferreira, 1983, each lack girdle hairs, 
have tricuspid lateral teeth, and have densely 
packed unaligned tegmental pustules on head 
and tail valves and lateral areas of intermediate 
valves. Although relatively smaller than pus- 
tules on species in the following group, densities 
and arrangements of these pustules are sug- 
gestive of some species in that group. 

The next group includes C. janeirensis, the 
type-species of Calloplax. In addition, Chaeto- 
pleura gemma Dall, 1879, C staphylophera, n. 
sp., and C. hanselmani (Ferreira, 1982) all lack 
girdle hairs, have tricuspid lateral teeth, and 
have large tegmental pustules on the head and 
tail valves and lateral areas of intermediate 
valves. Pustules may be unaligned (C. staphy- 
lophera) or arranged in rows (C. gemma, C. 
hanselmani, C. janeirensis) which sometimes in 
C. janeirensis coalesce into radial ribs; two or 
more such ribs may occur on lateral areas of in- 
termediate valves. Girdle scales and spicules of 
species in this group resemble those of other 
species in the group moreso than they resemble 
those of any other Chaetopleura species (for ex- 
ample, see C. apiculata. Fig. 21). 

Chaetopleura duncana (Dall, 1919) and C. 
ririparn (Plate, 1899) pose additional problems 
in placement. Each lacks girdle hairs, has tricus- 



pid lateral teeth, has strong radial ribs on head 
and tail valves, and has only two such ribs on 
lateral areas of intermediate valves. The low, 
conical or dome-like girdle scales of these 
species as illustrated by Ferreira (1978) are dis- 
similar from any other species of Chaeto- 
pleuridae. 

Additionally, there are at least three species 
of Chaetopleura in South Africa, possibly two in 
west Africa, one in east Africa, and one in east 
Asia (Ferreira, 1983a, b). Insufficient informa- 
tion is available to determine where most of 
these fit in the above arrangement. 

Acknowledgments 

Hugh J. Porter, University of North Carolina 
Marine Science Institute, Morehead City, pro- 
vided his previously reported specimen for 
study. John Reed and Dr. Robert A vent allowed 
study of material collected during their study of 
the deep-water Oculina reef community, spon- 
sored by the Harbor Branch Foundation, off 
central eastern Florida. Johnnie Johnson, 
Brevard Museum, Inc., provided specimens 
from the calico scallop grounds near Cape 
Canaveral. Jack N. Worsfold, Freeport, Grand 
Bahama, provided the single valves from that 
area. Lana Tester, formerly FDNR Bureau of 
Marine Research, produced the SEM photo- 
micrographs, and Sally D. Kaicher provided 
additional darkroom assistance. Dr. James F. 
Quinn, Jr., FDNR, provided guidance in Greek 
grammar. All are gratefully thanked. 

LITERATURE CITED 

Avent. R. M., M. E. King and R. H. Gore. 1977. Trophic and 
faunal studies of shelf-edge prominences off the central 
eastern Florida coast. Int. Revue ges. HydrobioL 62: 
18.5-208. 

Bullock, R. C. 1972. On the taxonomy of ( 'haetopleurafulva 
(Wood, 1815)(Mollusca: Polyplacophora). Occ. Pap. Moll, 
Mus. Comp. Zool, Harvard Univ. 3(42):177-191. 

Burghardt. G. and L. K. Bunrhardt. Hni9. A collector's 
guide to west coast chitons. Spec. Publ. No. 4, San 
Francisco Aquarium Soc, Inc. 45 pp., 4 pis. 

Clark, R. N. 1982. Chitons of the north-east Pacific. Of Sea 
and Shore 12(3): 147-153. 

Dall, W. H. 1879. Report on the limpets and chitons of the 
Alaskan and Arctic regions, with descriptions of genera 
and species believed to lie new. Proc. U.S. Natl Mus. 
1:281-344, 5 pis. 

1919. Descriptions of new species of chitons 

from the Pacific coast of America. Proc. U.S. Natl. Mus. 
55(2283):449-516. 



44 THE NAUTILI'S 



April 29, 1985 



Vol. 99(2-3) 



Ferreira, A. J. L978. The genus Calloplaj- Thiele, 1909 
(Mollusca: Polyplacophora) in the Americas. Bull. So. 
Calif. Acad. Sci. 77(2):56-64. 

1979. The genus Callistochiton Dall. 1879 

(Mollusca: Polyplacophora) in the eastern Pacific, with the 

description of a new species. Veliger 21(4):444-466, 3 pis. 

1982. A new species of Calloplaj (Mollusca: 



Polyplacophora) in the eastern Pacific. Veliger 24(4): 
321-324, 1 pi. 

1983a. The genus Chaetopleura Shuttleworth, 



1853 (Mollusca: Polyplacophora) in the warm-temperate 
and tropical eastern Pacific, southern California to Peru, 
with the description of two new species. Veliger 25(3): 
203-224, 4 pis. 
1983b. Researches on the coast of Somalia. The 



Chiton fauna (Mollusca Polyplacophora). Hal. J. Zoo/., 

n.s., Suppl. 18, 9:249-297. 
Gray, J. E. 1828. Spicilegia Zoological or Original Figures 

and Short Systematic Descriptions of New and Unfigured 

Animals. Part 1: 8 pp, 6 pis. British Museum. 
Joyce, E. A., Jr. and J. Williams. 1969. Rationale and 

pertinent data. Mem. Hourglass Cruises 1(1): 1—50. 
Kaas, P. 1972. Polyplacophora of the Caribbean region. 

Stud. Fauna Curasao and other Caribb. Ids. 41(137): 

1-162, pis. 1-9. 
Kaas, P. and R. A. Van Belle. 1980. Catalogue of Living 

Chitons. W. Backhuys, Rotterdam. 144 pp. 
Kennedy, F. S., Jr., J. J. Crane, R. A. Schlieder and D. G. 

Barber. 1977. Studies of the rock shrimp, Sicyonia 

brevirostris, a new fishery resource on Florida's Atlantic 

shelf. Flo. Mar. Res. Publ. No. 27. 69 pp. 
Lyons, W. G. 1982. Comments on chitons (Mollusca: Poly- 
placophora) of the Bahama Islands. Bull. Am. Malaeol. 

Union 1982: 38, 39. Abstract. 
Orbigny, A. d'. 1841. Voyage dans VAmerique Meridionale 

(1826-1833), 5(3):482-489. 
Pilsbry, H. A. 1892. Polyplacophora, (Chitons). Lepido- 

pleuridae, Ischnochitonidae, Chitonidae, Mopaliidae. 

Manual ofConchology 14:1-350, pis. 1-68. 
Plate, L. H. 1899. Die anatomie und phylogenie der 

chitonen. Fauna Chilensis. Zool, Jahrb. 5(11):15-216, 

pis. 2-11. 
Porter, H. C. 1974. The North Carolina marine and 

estnarine Mollusca; an atlas of occurrence. Univ. North 



Carolina Inst. Mar. Sci., vi + 351 pp. 
Putnam, B. F. 1980. Taxonomic identification key to the 

described species of polyplacophoran mollusks of the west 

coast of North America (north of Mexico). Pacific Gas and 

Electric Co., Dept. of Engineering Research, Rpt. 411- 

79.342. 164 pp. 
Reed, J. K, R. H. Gore, L. E. Scottoand K. A. Wilson. 1982. 

Community composition, structure, areal and trophic 

relationships of decapods associated with shallow- and 

deep-water Oculina varicosa reefs: Studies on Decapod 

Crustacea from the Indian River region of Florida, XXIV. 

Bull, Mar. Sci. 32(3):761-786. 
Reeve, L. A. 1847. Monograph of the genus Chitnn. ' 'onch. 

lam. 4, 28 pis. 
Righi, G. 1967. Sobre Polyplacophora do litoral Brasileiro. 

Pap. Avul. Zool. Sao Paulo, 20(9):85-97. 

1970. Mollusques polyplacophores. Resultats 

scientifiques des campagnes de la "Calypso" au large des 

cotes Atlantiques de VAmerique du Sud (1961-1962) 

9(19):107-114. 
Say, T. 1834. American rmichology. or descriptions of the 

shells of North America. Part 7. Appendix. 
Shuttleworth, R. 1853. Uber den Bau der Chitoniden, mit 

Aufzahlung der die Antillen und die Canarischen Inseln 

bewohnenden Arten. Mitth. Naturf. Ges. Bern (286-291): 

169-207. 
1856. Description de nouvelles especes. Premiere 

decade: especes nouvelles pour la faune des Antilles. 

Jour, de Conchyl. 5:168-175. 
Smith, A. G. and A. J. Ferreira. 1977. Chiton fauna of the 

Galapagos Islands. Veliger 20(2):82-97. 4 pis. 
Spengler, L. 1797. Udforlig Beskrivelse ovet det manges- 

kallede Konkylie-Slaegt af Linnaeus kaldet Chiton met 

endeel nye Arten og Varieter. SkrivL Naturkist. Selsk. 

4(0:62-1 03. 
Thiele, J. 1893. Polyplacophora, Lepidoglossa, Schuppen- 

zilngler. Pp. 353-401, pis. 30-32 in F. H. Troschel. Das 

Gebiss der Schnecken zur Begriindung einer naturliehen 

Classification, 2. 
1909. Revision des Systems der Chitonen. Teil 

I. Chun's Zoologiea 22(56):l-70, figs. A-E, pis. 1-6. 
1929. Handbuch der systematischen Weichtier- 



kunde. Loricata. 1(1): 1-22. Jena. 



Conchologists of America 

The annual meeting of the Conchologists of 
America will be held in Philadelphia June 22-26, 
1985, where it will be hosted by the Philadelphia 
Shell Club at the Academy of Natural Sciences 
of Philadelphia and a nearby hotel. For reserva- 
tion forms write: Frank Roach, 1028 Belvoir 
Rd., Norristown, PA 19401. 



1985 AMU Meeting 

The American Malacological Union will hold 
its annual meeting on the campus of the Univer- 
sity of Rhode Island on July 29-August 3, 1985. 
For further information please contact Dr. M. 
R. Carriker, College of Marine Studies, Univer- 
sity of Delaware, Lewes, DE 19958. 



Vol. 99 (2-3) 



April 29, 1985 



THE NAUTILUS 45 



ARENE FLEXISPINA. A NEW SPECIES (GASTROPODA: LIOTIIDAE) 

FROM OFF EASTERN BRAZIL 

Jose Henrique N. Leal 1 and Arnaldo C. dos Santos Coelho 

Setor de Malacologia 2 - Museu National 

20.942 - Rio de Janeiro, RJ - Brasil 



Seven species of the genus Arene H. & A. 
Adams, 1854 are already known from the Brazil- 
ian coast: Arene tricarinata (Stearns, 1872), A. 
briareus (Dall, 1881), A. variabilis (Dall, 1889), 
A. bairdii (Dall, 1889), A. brasiliana (Dall, 
1927), A. riisei Rehder, 1943 (Abbott, 1974; 
Rios, 1975) and A. notialis Marini, 1975 (Marini, 
1975). The present description is based on speci- 
mens obtained through bottom sampling (van 
Veen and Petersen grabs) between 54 and 82 
meter depth during the GEOMAR X cruise 
undertaken by the Brazilian Navy research 
vessel "N.Oc. Almirante Camara" along the 
eastern coast of Brazil, in the period of 01-11 
June 1978. Sampled substrate in the three sta- 
tions where the species was found consisted of 
fragments of calcareous algae and calcareous 
gravel. Although soft parts are not preserved, 
thus making difficult a more accurate taxonomic 
characterization, shell features are markedly 
distinct. 

Arene flexispina new species 
(Figs. 1-3) 
Description: Shell small, solid, trochoid in 
shape, reddish brown, with spiral rows and 
spines of lighter color. Ratio height/width of the 
shell higher in adults than in younger speci- 
mens. Whorls 5V2, the first IV2 comprising the 
protoconch, white and smooth, lower than the 
subsequent whorl. Teleoconch whorls with 2 
larger peripheral spiral rows of 10 or 11 large, 
fluted spines spirally raised and imbricated. 
Narrower row 1-2 subsutural, one intermediate 
(between the 2 larger) and one immediately 
above the subsequent whorl, with numerous im- 
bricated scale-like spines, smaller than those in 
the 2 larger rows. Finely incised axial lines on 
entire shell microscopic and crowded. Suture 



'Present address: B.L.R., Rosenstiel School of Marine and 
Atmospheric Science, 4600 Rickenbacker Causeway, Miami, 
FL 33149 
Contribution no. 46 



channeled, clearly defined. Body whorl rounded, 
with wider spiral cords; spines in the 2 larger 
cords triangular, bent outwards and sharply 
pointed in apical view; spines number the same 
as in the spire. Base with 4 or 5 well-separated 
beaded spiral cords; beads almost imperceptible 
in worn specimens. Cord bordering the umbili- 
cus the same size or only slightly larger than the 
other basal cords (younger specimens). Um- 
bilicus wide, deep and twisted, with fine axial 
lines internally. One or two cords entering the 
umbilicus in younger shells, absent in mature 
specimens. Aperture whitish, oblique. Outer lip 
thin, with crenulations corresponding to the ex- 
ternal spiral ornamentation. Operculum round, 
multispiral, with small radial lines giving beaded 
aspect to its calcareous external surface. 
Attachment side horny and convex. 

Material examined: GEOMAR X station 048, 
40 km off Ponta de Corumbau, Bahia, Brazil 
(16°56'30"S, 38°39'30"W), 80 m depth, "N.Oc. 
Almirante Camara" col. 09 June 1978, Holotype, 
Museu National, Rio de Janeiro, Brazil (Col.Mol. 
MN 5352), height 6.4 mm, width 6.7 mm; Para- 
type 1, United States National Museum, Wash- 
ington, D.C. (USNM 820786), height 5.4 mm, 
width 6.2 mm; Paratype 2 (Col.Mol.MN 5353), 
height 4.7 mm, width 5.4 mm; Paratype 3, 
Museu Oceanografico, Fundacao Universidade 
do Rio Grande, Rio Grande, Brazil (MORG 
22807), height 3.5 mm, width 4.5 mm; Paratype 
4 (USNM 820786A), height 3.4 mm, width 4.3 
mm; Paratype 5 (MORG 22808), height 3.2 mm, 
width 4.3 mm; GEOMAR X station 038, 170 km 
off Conceicao da Barra, Espirito Santo, Brazil 
(18°49'00"S, 37°52'00"W), 54 m depth, "N.Oc. 
Almirante Camara" col. 07 June 1978, Paratype 
6 (MORG 22619), height 2.0 mm, width 3.0 mm; 
GEOMAR X station 047, 120 km off Abrolhos 
Reef, Bahia, Brazil (17°44'00"S, 37°21'00"W), 54 
m depth, "N.Oc. Almirante Camara" col. 08 
June 1978, Paratype 7 (Col.Mol.MN 5354), 
height 1.4 mm, width 2.4 mm. 



46 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 




FIGS. 1-3. Arene flexispina n. sp. 1 and 2, Apertural and 
ventral views of the holotype, Col.Mol.MN 5352, 40 km off 
de Corumbau, Bahia State, Brazil. Scale bar=2 mm. 
.'!. Apertural view with operculum of the paratype >'<. MORG 
■ off ( 'onceicao da Barra, Espirito Santo State, 
Brazil. Scale bar= 1 mm. 



Type locality: Brazil, Bahia State, 40 km off 
Ponta do Corumbau, (16°56'30"S, 38°39'30"W), 
80 m depth, calcareous algae bottom (Fig. 4). 

Etymology: The specific name stands for the 
large outwardly bent spines in the spiral cords 
of the spire and body whorl. 

Remarks: The species seems to belong in the 
subgenus Arene s.s. which is, as stated by Keen 
(1971:345), characterized by a sculpture of 
coarsely beaded spiral cording on the body 
whorl and base, the periphery rounded or 
stellate. Although A. flexispina n. sp. possesses 
some of the characters of the subgenus Mareval- 
vata Olsson & Harbison, 1953, such as general 
outline, spiral cords in the umbilicus wanting in 
mature specimens and outer lip not thickened, it 
doesn't exhibit the diagnostic flattened base 
with radial lines extended from the umbilicus 
and a nacreous inner layer (Olsson & Harbison, 
1953:348; Keen, 1971:346). Further investiga- 
tions or a revision work on the western Atlantic 
species of Arene seems to be necessary to con- 
firm the positioning of A. flexispina at 
subgeneric level. 



17 



18 



BAHIA 
STATE 



BRAZIL 




048 



ABROLHOS 

REEF 
COMPLEX 



047 



038 




FIG. 4. Location of the three GE( >MAK X stations in which 
Arene flexispina n. sp. was found (solid triangles). The type 
lecality is represented by station (MS. Inset shows position of 
the area in southern Atlantic Ocean. 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 47 



It was observed from the shell measures of the 
8 examined specimens of A. Jlexispina that the 
ratio height/width increases as the shell grows, 
suggesting a pattern of allometrie growth (Fig. 
5), probably a consequence of a gradual altera- 
tion in the angle of coiling in the species. 

A rene Jlexispina appears to be related to A. 
briareus from the Caribbean and tropical west- 
ern Atlantic, according to the original descrip- 
tion (Dall, 1881:52), and later illustration by the 
same author (Dall, 1889: pi. 24, figs. 5, 5a), and 
by comparison of specimens (Col.Mol.MN 5390; 
Morg 14.969), mainly by its elevated spire and 
spinose ornamentation. A. jlexispina differs, 
however, by its darker color, two obviously 
larger cords on body whorl, which are all about 
the same size or only a little larger than the re- 
maining in briareus; ornamentation of the spiral 
cords consisting in about 11 large fluted spines, 
instead of about 40 small spines in briareus; a 
well differentiated ridge or cord around the um- 
bilicus and a nodulose spiral ridge inside it in 
briareus, not present in Jlexispina; outer lip 
thicker in briareus. 

Arene notialis from off southeastern Brazil 
differs by its whitish color, lower spire, about 21 



8 










{ 


V- 


6 










c _S 


-O 


I 
m 






b 


Q 


X. 


• 


3 

3 


n 


"j 










2 


Cf3 J 




•—A 


A. 








^^i 


1 




















- — w — - 





width (mm) 

FIG. 5. Allometrie shell growth in Arene jlexispina n. sp.; 
sketches illustrate the shape of shells at three points on the 
curve: a) Paratype 7, Col.Mol.MN 5354, height 1.4 mm, 
width 2.4mm; b) Paratype 3. MORG 22807, height 3.5 mm, 
width 4.5 mm; c) Holotype. Col.Mol.MN 5352, height 6.4 
mm, width 6.7 mm. Scale bars= 1 mm. 



nodules (not spines) on spiral cords in the body 
whorl, 8 joined strongly beaded basal spiral 
cords instead of 5 separated cords in Jlexispina; 
umbilicus smaller and straight, bordered by a 
larger basal cord and outer lip thicker in 
notialis, according to Marini (1975) and material 
examined of A. notialis from off Guarapari, 
Espirito Santo, Brazil, "N.Oc. Almirante 
Saldanha" col. September 1968, 80 m depth, 
Col.Mol.MN 4862, two specimens. 

Acknowledgments 

We are indebted to Dr. Donald R. Moore from 
the Rosenstiel School of Marine and Atmos- 
pheric Science, Miami, for the critical review of 
the manuscript, to the staff at Departamento de 
Hidrografia e Navegacao, Ministerio da 
Marinha, Brazil, for providing the adequate con- 
ditions to the obtention of the material exa- 
mined, during the GEOMAR X cruise, to Prof. 
Eliezer de C. Rios, Museu Oceanografico, Rio 
Grande, Brazil, who made available part of the 
studied material and to Mr. Raul Garcia, Rio de 
Janeiro, Brazil, for the drawings of Arene Jlex- 
ispina. 

LITERATURE CITED 

Abbott, R. T. 1974. American Seashells (2nd Edition). Van 
Nostrand-Reinhold, New York, 663 pp. 

Dall, W. H. 1881. Reports on the Results of Dredging, under 
the Supervision of Alexander Agassiz, in the Gulf of 
Mexico, and in the Caribbean Sea, 1877-79, by the United 
States Coast Survey Steamer "Blake", . . . XV. Prelimi- 
nary Report on the Mollusca. Bull. Mus. Comp. Zooi. 
Harvard Univ., Cambridge 12(6):171-318, pis. 1-9. 

1889. Reports on the Results of Dredging, under 

the Supervision of Alexander Agassiz, in the Gulf of 
Mexico (1877-78) and in the Caribbean Sea (1879-80), by 
the U.S. Coast Survey Steamer "Blake", . . . XXIX. - 
Report on the Mollusca. Part II. - Gastropoda and Scapho- 
poda. Bull. Mus. Comp. Zool. Harvard Univ., Cambridge 
18:1-492. 31 pis. 

Keen, A. M. 1971. Sea Shells of Tropical West America. 
Stanford University Press, Stanford, 1064 pp. 

Marini, A. C. 1975. Sobre duas especies novas de micro- 
moluscos (Trochacea: Turbinidae; Liotiidae) da costa 
brasileira. Pap. Ainil. Zool. St. Paulo 29(5):31-34, 2 pis. 

Olsson, A. A. and A. Harbison. 1953. Pliocene Mollusca of 
Southern Florida, with special reference to those from 
North Saint Petersburg with special chapters on Turridae 
by Williams G. Fargo and Vitrinellidae and Fresh-water 
Mollusks by Henry A. Pilsbry. Acad. Nat. Sci. Philad.. 
Monog. 8:1-457, 65 pis. 

Rios, E. C. 1975. Brazilian Marine Mollusks Iconography: 
Fundacao Universidade do Rio Grande, Rio Grande, 
331 pp., 91 pis. 



48 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



AN EXCEPTIONAL STREAM POPULATION OF THE BANDED 
APPLE SNAIL, VIVIPARUS GEORGIANUS, IN MICHIGAN 



Gary L. Pace and Ernest J. Szuch 

Department of Biology 

University of Michigan-Flint 

Flint, MI 48502-2186 

ABSTRACT 
SCUBA and a Surber sampler were used to study a stream population of 
Viviparus georgianus (Lea). This locality, at the mouth ofRunyan Creek where it 
flows into Hoisington Lake in Livingston County, Michigan, is only the fourth 
known locality for any species of Viviparus in that state. Densities were high (up 
to 86^/m 2 ) and varied significantly with gender (female > male), station type 
(reach > meander), and station position (upstream > downstream). Mean weight 
varied in the same ways with respect to gender and station type, but conversely for 
station position (whether downstream or upstream). The only effective interaction 
between factors was that between gender and station position: females decreased 
in size upstream faster than males. Weight -frequency data combined for all sta- 
tions supported the independent measures of sex ratio (females > males) and sex- 
ual dimorphism in size. 



The main purpose of this paper is to draw at- 
tention to the fourth known population of Vivi- 
parus georgianus from Michigan. Voucher 
specimens have been deposited in the University 
of Michigan Museum of Zoology. The population 
thrives in Runyan Creek where it flows into 
Hoisington Lake in northern Livingston Coun- 
ty. Here the stream is narrow (less than 6 m), 
steep-sided, and varies in depth from 85 to 156 
cm as it meanders through an extensive marsh. 
The substrate is largely organic detritus con- 
tributed from marsh and stream plants (e.g., 
Spartina pectinata, Scirpus lineatus, Typha 
latifolia, Nuphar variegatum, Lythrum deco- 
don). Our interest in this population derives 
from the rarity of this species in Michigan and 
from the very high densities found in a locality 
which must be very near this species' northern 
limits of distribution. 

Since its discovery by two of our students, 
Donald House and Philip Davis, several papers 
have been published on the physiology of these 
snails (Fitch, 1975, 1976; Buckingham & Freed, 
1976; Davis & Fenner, 1977; Studier & Pace, 
1978). Ecological studies on this and related 
species include those of Van Cleave & Lederer 
(1932), Stanczykowska, et al. (1971, 1972), Burla 
(1972), Samochwalenko & Stanczykowska 
(1972), Young (1975), de Bernardi, et al. (1976), 



Brown (1978), Plinski, et al. (1978), Vail (1978), 
Imlay, et al. (1981), Jokinen (1982) and Thomp- 
son (1985). The main studies of the systematics 
and distribution of North American viviparids 
were those of Clench (1962) and Clench & Fuller 
(1965). 

Materials and Methods 

Many species of temperate, freshwater mol- 
lusks including Viviparus, move to deeper 
water, burrow into the substrate, and become 
less active during the Fall and Winter (Burla, 
1972; Young, 1975). Therefore, when dredging 
and SCUBA assisted visual search methods 
have been used to collect these mollusks, this 
Fall migration has resulted in the under- 
sampling of the population (Burla, 1972; Young, 
1975; de Bernardi, et al. 1976). In narrow, steep- 
sided channels, however, this Fall migratory 
behavior serves to concentrate the population 
into the bottom detritus. Under these circum- 
stances, the Fall may very well be the best 
single time of the year to study certain popula- 
tion characteristics. 

During the last week of September, SCUBA, 
was used to collect three Surber samples (0.093 
m 2 x 7.62 cm) at each of 12 stations selected at 
the centers of consecutive stream meanders and 
reaches. Since samples were collected from 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 49 



meanders and reaches whose radii and lengths 
varied considerably, stream channel distances 
between stations were not equal. The samples 
were taken from the deepest part of the stream 
cross-section with minor adjustments where 
water-lily rhizomes prevented forcing the 
sampler fully into the substrate. Everything 
within the frame was then scooped into the 
Surber net, brought to the surface, and trans- 
ferred to labeled plastic containers for transport 
to the laboratory. In the lab, snails were sorted 
from the detritus, sexed, and then weighed on a 
top-loading balance to 0.01 g. Wet (live) body 
weight was used since Davis and Fenner (1977) 
showed its direct relationship to dry weight for 
these snails. 

Results' 

Total densities ranged from 151/m 2 to a max- 
imum of 864/m 2 . The average population den- 
sities were significantly higher in the reaches 
(608/m 2 ) than in the meanders (534/m 2 ). Closer 
examination showed that the average density of 
the males was the same in these two types of 
habitats (243:228/m 2 ). The difference, therefore, 
was in the number of females (365:306/m 2 ). 
While females outnumbered males in all stations 
combined (female/male = 1.42), the difference 
was greater in reaches (female/male = 1.50) than 
in meanders (female/male = 1.34). A comparison 
was also made between the six most down- 
stream stations and the six most upstream sta- 
tions. An average density of 462/m 2 was found 
for the downstream populations, while that of 
the upstream group was 680/m 2 . Thus, the 
upstream populations were significantly denser 
than the downstream populations. 

Live body- weight averages computed for each 
station (sexes combined) ranged from 0.75-1.97 
g. The average size of the reach snails (1.57 g) 
was larger than that of the meander snails (1.35 
g). Also, the average size of the females (1.90 g) 
was nearly twice that of the males (1.01 g). Fur- 
thermore, while the average size of both sexes 
decreased upstream, females decreased faster 
than males (Fig. 1). 

Frequency distributions of weight classes for 
each sex were constructed for each station 



1.0 



' 








:! 








j^- 


* 




i 


T 


I 


I 






i — 


■ — ^___ 








i 

I 


T — — «»1^ 






' 


i 1 1 



'Readers wishing tabular data on density and mean weight 
distributions among the stations along with their statistical 
analyses may write the authors for copies. 



4-5 6-7 8-9 10-11 12-13 14-15 

S tation No 
(Upstream -*) 

FIG. 1. Rates of change in male and female mean weights 
with stream position. Each point represents the mean of 20 
meander and 20 reach snails selected randomly. The vertical 
bars represent +/- 2 Standard Errors. The curves are 
regression lines based on the mean weights for males and 
females separately. Females: Intercept = 2.378, Slope = 
-0.162. Males: Intercept = 1.308, Slope = -0.088. 

separately and for all stations combined. All 
curves for both sexes showed bimodal distribu- 
tions of weight classes. Because the results were 
comparable for all stations, curves are provided 
only for the combined data (Fig. 2). We assume 
that size is at least roughly correlated with age 
(de Bernardi, et al., 1976) and we will refer to 
the obvious groupings in Fig. 2 as cohorts. 

The younger cohort for each sex had a mode at 
about 0.5 g, and ranged from 0.2-0.8 g for males 
and from 0.2-1.0 g for females. Females were 
slightly larger than males in this cohort, and 
outnumbered males 616 to 518. In the older 
cohort, 358 males weighed from 0.9-3.5 g, while 
606 females weighed from 1.1-8.9 g. These 
curves, as well as the data already discussed in- 
dicate that the average adult female is nearly 
twice as large as the average adult male. Note 
also that there is no significant difference be- 
tween the number of females in the two cohorts 
(616 & 606) and that in each, females out- 
numbered males (518 & 358). Finally, note that 
males were more numerous in the younger 
cohort than in the older one. 

Discussion 

As the papers by Clench (1962) and Clench & 
Fuller (1965) have documented, Viviparus 
i/mri/nunis (Lea) has apparently only invaded 



50 THE NAUTILUS 



April 29, 1985 



Vol. 99 (2-3) 



— Mole 
-_ Femole 




it ft « 

« \ A A 






r*V-- 



10 20 30 40 50 60 70 

Wl |gm) 

FIG. 2. Weight-frequency curves for all snails, sexes separate. 



the northern states during the last century. Fur- 
thermore, Clench pointed out that only three 
localities are known from Michigan, and that 
these have been presented to the University of 
Michigan Museum of Zoology since the publica- 
tion of Winslow's (1926) checklist of Michigan 
mollusks: UMMZ 166266 and 177214: Coguac 
Lake, 2 mi S.W. Battle Creek, Calhoun Co., 
Leslie Hubricht. Oct. 6, 1946; UMMZ 167226: 
Park N. of Owasso, Shiawassee Co., H. van der 
Schalie & Aurele LaRocque. July 10, 1947; 
UMMZ 173445: S. side Silver Lake, 15 mi N.E. 
Grand Rapids, Kent Co., C. D. Nelson. (No date 
recorded). 

While it is possible that any specific locality 
may have long been populated and yet over- 
looked by collectors, it must be admitted that 
\'irij„,rus is rare in Michigan. It is well-known 
that Michigan's molluscan fauna has long been 
among the best known in the world. Neverthe- 
less, the above four lots of V. georgianus are in 
contrast to hundreds of lots of Michigan 
Campeloma integrum and C. decisum which fill 5 
and 7 UMMZ cabinet drawers, respectively. 

Not only is this one of the few Michigan 
localities for Viviparus, but it appears that 



among those so far reported, this locality most 
closely approaches this species' optimal habitat. 
This is supported by the fact that the population 
reached a maximum density of 864/m i and a 
maximum standing crop biomass (density x 
average live weight) of 1163 g/m 2 . These data 
are higher than any yet reported for this species 
(Van Cleave & Lederer, 1932; Vail, 1978; 
Browne, 1978). Furthermore, these data exceed 
those for any freshwater snails (Hyman, 1967) 
and may prove to represent one of the largest 
standing crop biomass records among fresh- 
water gastropods. These results are unexpected 
for a locality so near the northern limits of a 
species' range. The timing and method of collec- 
tion must certainly have contributed to these 
high numbers (see Materials and Methods). The 
substrate in this habitat is very rich in organic 
detritus derived from the breakdown of the 
plants of the extensive marsh through which 
Runyan Creek slowly meanders. Earlier reports 
of a fine detritus habitat preference (Harman, 
1972), and of combined detritus (Fretter & 
Graham, 1978) and filter (Cook, 1949) feeding 
methods by Viviparus species, provide some ex- 
planation for the optimal nature of this habitat. 
It certainly seems better suited to this species 
than its usually reported habitat "on the bottom 



Vol. 99 (2-3) 



April 29, 1985 



THE NAUTILUS 51 



of mesotrophic or eutrophic lakes and ponds" 
(Browne, 1978). Indeed, at the mouth of Runyan 
Creek into Hoisington Lake, the density of these 
snails drops to less than one snail per square 
meter. The fact that these snails thrive in this 
detritus-rich habitat so near to their northern 
limits of distribution may indicate that food 
availability outweighs temperature or length of 
growing season in determining their optimal 
habitat. 

Both sexual size dimorphism and disparate 
sex ratios have previously been recorded for 
northern populations of this (Van Cleave & 
Lederer, 1932; Browne, 1978) and other species 
of viviparids (Annandale & Sewell, 1921; van 
der Schalie, 1965; de Bernaardi, et aL, 1976; 
Vail, 1978). In Vail's (1978) Florida populations 
of Viviparus georgianus, however, sexual size 
dimorphism did not occur, and differences in sex 
ratios were not noted. Thus there seems to be 
both local and geographical variation in these 
sexual attributes. In our studies, variation in sex 
ratio could not be shown to be dependent on any 
of the following variables: station type (meander 
vs reach), station position (upstream vs down- 
stream), water depth, water temperature, total 
density, or total biomass. Our large sample 
sizes, however, reduce the possibility that the 
variation is the result of sampling error. That 
these sexual differences are due to higher 
female growth rates and longer female longe- 
vity is suggested by our size-frequency data 
(Fig. 2) which support the findings of others 
(Van Cleave & Lederer, 1932; Browne, 1978). 
Because we made our collections in late 
September, our cohorts represent snails that 
had survived one growing season (about 4 
months) and those which had survived at least 
two growing seasons and one winter (16-19 
months). Some differential mortality (males > 
females) and differential growth (females > 
males) was evident by the end of the first grow- 
ing season and increased substantially by the 
end of the second. That these differences are not 
due to differential numbers and size at birth is 
supported on both factual and theoretical 
grounds. Van Cleave and Lederer (1932) found 
that the two sexes were present in equal 
numbers at birth. Fisher showed long ago that 
this is to be expected if there is no sexual dif- 
ference in energy costs (i.e., no difference in 



size) of the progeny to the parent (Pianka, 
1974). Brown (1978), on bioenergetic and 
anatomical grounds suggested that "selection 
probably drives females toward a larger size 
than males as a consequence of the cost of 
viviparity." Furthermore, Browne pointed out 
that males have two options in dividing their 
energy resources. Evidently, some males devote 
much of the first year in feeding and survival, 
with most reproductive effort delayed until the 
second growing season. Other males might 
spend most of their time and energy actively 
seeking females while spending relatively less 
time feeding. While the latter were characteris- 
tic of Browne's populations and would generally 
be expected to leave more progeny, variation in 
such strategies could account for some of the 
variation in the distribution of sexual differ- 
ences in size and number. 

The fact that these snails are larger and more 
numerous in reaches than in meanders seems 
more easily testable. Higher currents in the 
meanders may reasonably be expected to re- 
move both young snails and detritus and deposit 
them in the reaches. Even if the current rarely 
displaces snails, the cumulative effect of erosion 
and deposition on habitat enrichment in the 
reaches could account for the differences in snail 
density and biomass. Analysis of the variation of 
the current velocity and sediment load between 
habitat types and between seasons would be 
very helpful in answering these questions. 

It is perplexing that density and biomass in- 
crease upstream while mean weights decrease 
(see Results). Since biomass increases upstream 
we might inquire whether the carrying capacity 
{e.g., as determined by food availability) in- 
creases upstream, or whether the upstream pop- 
ulations are more efficient in filling their niche. 
The first seems a more testable question. 
Because upstream populations are denser but 
individuals are smaller, we may ask whether or 
not these snails are stunted as a result of 
crowding {i.e., intraspecific competition). Also, 
the larger size but lower density of the down- 
stream snails may indicate that while some ex- 
trinsic factor controls numbers, surviving snails 
have ecological room for growth (i.e., crowding 
reduced). Higher predation pressure on small 
downstream snails could account for such popu- 
lation characteristics. The seasonally dense 



52 THE NAUTILI'S 



April 29, 1985 



Vol. 99(2-3) 



populations of ducks and geese on Hoisington 
Lake and the possibility of lake fish foraging 
some distance upstream could provide the gra- 
dient in predation pressure. The importance of 
ducks as mollusk predators is well known 
(Malone, 1965; Thompson, 1973). de Bernardi et 
al. (1978) attribute substantial modification of 
population structure to predation by ducks, and 
Price (1957) has shown the importance of lake 
fish predation on viviparids. Small snails with 
their weaker shells would be subject to higher 
predation rates than large snails. In other 
words, snails that survive to a certain size have 
escaped a major source of mortality (i.e., preda- 
tion). These snails, relatively few in number, 
would not be subjected to high intraspecific com- 
petition and would grow to a relatively large 
size. That stunting is occurring upstream might 
also be inferred from the fact that females get 
larger faster than males as we sample further 
and further downstream. Since females seem to 
have higher growth rates and greater reproduc- 
tive energy requirements (because of vivipar- 
ity), they may be more easily stunted in the 
more crowded upstream habitats. Conversely, 
under conditions of lower density and presumed 
higher detritus deposition downstream, females 
may be freer to express their genetically deter- 
mined faster growing rates. The above specula- 
tion obviously suggests a variety of future 
studies. These would include analyses of the 
relative organic content and depth of sediments 
in the different stream habitats. In addition, it 
would be beneficial to observe the feeding 
behavior of potential predators, and to actually 
examine their stomach contents. Furthermore, 
predator and competitor exclusion pens could be 
set up in the various habitats to test the actual 
effects of these factors. Finally, laboratory and 
field growth experiments would be invaluable in 
testing our hypotheses. 

Acknowledgments 

The authors are grateful to Phillip Davis and 
Donald House for pointing out the existence of 
this population, and Gregory Panos, III, for help 
with collecting the snails. Theodore Herzog of 
our Computer Center was especially helpful in 
processing the data. We are particularly in- 
debted to Dr. Richard W. Dapson for his sub- 
stantial assistance in the statistical analysis of 



these data and to Dr. Eugene Studier for 
critically reading the manuscript. The research 
for this project was assisted by grants from the 
Faculty Development Fund of the University of 
Michigan-Flint. 



LITERATURE CITED 

Annandale, N. and R. B. S. Sewell. 1921. The banded pond 
snail of India. Rcc Indian Mus. 22:217-292. 

Browne, R. A. 1978. Growth, mortality, fecundity, biomass, 
and productivity of four lake populations of the proso- 
branch snail, Viviparus georgianus. Ecology 59:742-750. 

Buckingham, M. J. and D. E. Freed. 1976. Oxygen consump- 
tion in the prosobranch snail Viviparus eontectoides 
(Mollusca: Gastropoda) -II. Effects of temperature and 
pH. Comp. Biochem, Physiol. 53A:249-252. 

Burla, H. 1972. Die Abundanz von Anodonta, Unio pic- 
torum, Viviparus a tor. Lymnaea auricularia und Lym- 
naea ovata in Zurichsee, in Abhangigkeit von der Wasser- 
tiefe und zu verschiedenen Jahreszeiten. Vierteljahrs. 
Naturforsch. Ges, Zurich, 117:129-151. 

Clench, William J. 1962. a catalogue of the Viviparidae of 
North America with notes on the distribution of I 'i vipa rus 
georgianus Lea. Occ. Papers Moll. 2:261-287; 385-412. 

Davis, P. B. and H. K. Fenner. 1977. A simple technique for 
predicting the biomass of a prosobranch snail. Comp. 
Biochem. Physiol. 56A:127-128. 

de Bernardi, R., 0. Ravera. and B. Oregioni. 1976. Demo- 
graphic structure and biometrie characteristics of Vivi- 
parus ater Cristofori and Jan (Gasteropoda: Proso- 
branchia) from Lake Alserio (Northern Italy). Jour. Moll. 
Studies 42:310-318. 

Fitch, D. D. 1975. Oxygen consumption in the prosobranch 
snail Viviparus eontectoides (Mollusca: Gastropoda) -I. 
Effects of weight and activity. Comp. Biochem. Physiol 
51A:815-820. 

1976. Oxygen consumption in the prosobranch 

snail Viviparus eontectoides (Mollusca: Gastropoda) -III: 
Effects of light. Comp. Biochem. Physiol. 54A:253- 257. 

Fretter, V. and A. Graham. 1978. The Prosobranch Molluscs 
of Britain and Denmark, Part 3. Jour. Moll. Stiniirs. 
Suppl. 5:101-152. 

Harman, W. N. 1972. Benthic substrates: Their effect on 
fresh-water Mollusca. Ecology 53:271-276. 

Hyman, L. H. 1967. The Invertebrates: Vol VI. Mollusca /. 
McGraw-Hill Book Co.. N.Y. 1-792 p. 

Imlay, M. J., J. W. Arthur, B. J. Hailigan, and J. H. Stein- 
metz. 1981. Life cycle of the freshwater snail Campeloma 
decisum (Viviparidae) in the laboratory. The Nautilus 
95:84-88. 

Jokinen, E. H. 19.S2. Cipaugojialudiua chinensis (Gastro- 
poda: Viviparidae) in North America, review and update. 
The Nautilus 96:89-95. 

Malniie. (' I; 1965 [)i persal of aquatic gastropods via the 
intestinal tract of water birds. Tk Nautilus 78:135-139. 

Pianka, E. R. 1974. Evolutionary Ecology. Harper & Row, 
Publishers, N.Y. viii, 1-356 p. 

Plinski. M., W. Lawacz, A. Stanczykowska, and E. Magnin. 
1978. Etude quantitative et qualitative de la nourriture 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 53 



des Viviparus malleolus (Reeve) (Gastropoda, Proso- 
branchia) dans deux lacs de la region de Montreal. Can. 
Jour. Zool. 56:272-279. 

Price, J. H. 1957. A study of the food habits of some Lake 
Erie fish. U. S. Fish and Wildlife Service Report No. 837, 
1-105 p. 

Samochwalenko, T. and A. Stanczykowska. 1972. Fertility 
differentiation of two species of Viviparidae (Viviparus 
fasciatus Mueller and V. viviparus L.) in some en- 
vironments. Ekilogia Polska 20:479-492. 

Stanczykowska, A., E. Magnin, and A. Dumouchel. 1971. 
Etude de trois populations de Viviparus malleatus (Reeve) 
(Gastropoda, Prosobranchia) de la region de Montreal. I. 
Croissance, fecondite, biomasse et production annuelle. 
Can. Jour. Zool. 49:1431-1441. 

Stanczykowska, A., M. Plinski, and E. Magnin. 1972. Etude 
de trois populations de Viviparus malleatus (Reeve) 
(Gastropoda, Prosobranchia) de la region de Montreal. II. 
Etude qualitative et quantitative de la nourriture. Can. 
Jour. Zool, 50:1617-1624. 

Studier, E. H. and G. L. Pace. 1978. Oxygen consumption in 
the prosobranch snail Viviparus contectoides (Mollusca: 



Gastropoda) -IV. Effects of dissolved oxygen level, star- 
vation, density, symbiotic algae, substrate composition 
and osmotic pressure. Comp. Biochem. Physiol. 59A: 
199-203. 

Thompson, D. 1973. Feeding ecology of diving ducks on 
Keokuk Pool, Mississippi River. Jour. Wildlife Manage- 
ment 37:367-381. 

Thompson, Fred G. 1985. Fresh Water Snails of Florida -A 
Manual for Identification. University of Florida Press. 94 
pp., 193 figs. 

Vail, V. A. 1978. Seasonal reproductive patterns in 3 
viviparid gastropods. Malacologia 17:73-97. 

Van Cleave, H. J. and L. G. Lederer. 1932. Studies on the 
life cycle of the snail Viviparus contectoides. Jour. Morph. 
53:499-522. 

van der Schalie, H. 1965. Observations on the sex of 
t'umpeloma (Gastropoda: Viviparidae). Occ. Paps. Mus. 
Zool. Univ. Mich, 641:1-9. 

Young, M. R. 1975. The life cycle of six species of freshwater 
molluscs in the Worcester-Birmingham Canal. Proc. 
Malawi, Soc. Land. 41:533-548. 



MODERN METHODS USED TO AGE OCEANIC BIVALVES 

John W. Ropes 

National Marine Fisheries Service 

Northeast Fisheries Center 

Woods Hole Laboratory 

Woods Hole, MA 02543 



ABSTRACT 
Modern techniques of thin- sectioning chondrophores and the preparation of 
acetate peels of sectioned valves are described that expose internal age/growth 
structures of two commercially important U.S. oceanic bivalves, Spisula and 
Arctica. The application of the methods in specific studies is reviewed. Verifica- 
tion of annual age marks was based on mark-recapture experiments and length 
frequency analyses for both species. 



New methods have been under investigation 
by the Northeast Fisheries Center since the 
mid-1970's for determining the age and growth 
characteristics of the Atlantic surf clam, Spisula 
solidissima (Dillwyn), and ocean quahog, 
Arctica islandica (Linne), bivalves that supply 
the bulk (79% in 1983) of the meats for clam pro- 
duction in the United States. Goals of the inves- 
tigation were that the methods produce accu- 
rate age determinations and be efficient, since 
about 1,500 shell specimens of each species may 



be taken during annual surveys. Age determina- 
tions on a timely basis are specifically needed 
for evaluations of age composition in assess- 
ment studies of the populations. 

Bands or rings form annually on the external 
valve surface of some bivalves, much like rings 
found in tree trunks, and have been used to 
determine age (Lutz and Rhoads 1980). Similar 
bands appear on the valves of young surf clams 
and ocean quahogs up to about 15 years of age, 
but with increasing age and size the earlier 
bands are often obliterated by erosion and later 



54 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



bands become too crowded together at the valve 
margin for definite separation, even under 
microscopic examination. Confusing, unverifi- 
able and incomplete records are inevitable when 
such poorly defined shell features are used for 
age analysis. Thus, the use of such a general 
method for critical studies is precluded by the 
lack of accuracy in age determinations. 

Specific internal shell deposits that form an- 
nually have been found in other bivalves (Lutz 
and Rhoads 1980). They are considered to be 
relatively unaffected by external conditions 
causing erosion, but require care in exposing the 
deposits and critical microscopic examination. 
Therefore, methodologies were developed for 
examining such deposits in the shells of surf 
clams and ocean quahogs. 

Surf Clam Method 

Preliminary examinations of internal age/ 
growth features in the valves of surf clams were 
begun in 1975. Such examinations seemed justi- 
fied by the presence of thin, dark lines seen 
alternating with broader, white growth incre- 
ments in fossilized valves. Whole surf clam 
valves were cut in about one-half hour from the 
beginning (umbo) to the end of a clam's life at 
the valve margin using a diamond-impregnated 
saw blade (Fig. 1). The cut edges were then 
polished to remove saw marks and enhance the 
distinctive dark lines that were suspected to be 
age annuli. These lines curved down and back 
toward the umbo of a valve and became increas- 
ingly attenuated at the myostracal layer from a 
more prominent beginning beneath external 
bands. The myostracal layer separated inner 
and outer shell layers in these valves. The lines 
were validated as annual age marks by marking 
some surf clams for release and recovery at 
Chincoteague Inlet, VA (Ropes and Merrill 
1970; Jones et al. 1978). Ambrose et al. (1980), 
Jones (1980, 1981a and b, 1983), Jones et al. 
(1983), and Arthur et al. (1983) report studies 
based on the annual periodicity of these lines in 
surf clams. 

Age determinations of whole valves required 
careful microscopic examination of the cut sur- 
faces. Holding the valve level and in focus under 
the microscope proved difficult and even more 
frustrating when trying to make growth meas- 
urements. In addition, the cutting, polishing and 



cc 
3 




s 



8 



VENTRAL 



DORSAL D 

DIRECTION OF CUT 



Hinge ligament — 




/ 






/<Ti— ^ssSi 




- Umbo 


POSTERIOR 


/ ' / 
/ ' 

\ i / 
\ / 


f*0 


Tootn 

ANTERIOR 








Adductor muscle scar 


Pallid lint 









VENTRAL 

FIG. 1. Sketches of internal valve features and direction of 
cut (dashed line) (a) to remove part of the chondrophore 
(lightly stippled area) from a surf elam, S/iisuln vilitHssimn, 
(from Ropes and O'Brien 1979), and (b) to completely section 
the left valve of an ocean quahog, Arctica islandica, and a 
unique hinge tooth bearing age lines (from Ropes 1982). 

examination procedures required about one 
hour per specimen and were considered to be ex- 
cessively time consuming. Nevertheless, growth 
lines in the valves were clearly exposed and this 
was a necessary procedure used in establishing 
a basis for a more efficient method to follow. 

Ropes and O'Brien (1979) developed a new 
method of exposing age lines in a part of the 
hinge called the chondrophore (Fig. 1). This por- 
tion of the shell can be cut in less than a minute 
using two diamond-impregnated saw blades 
spaced 2 mm apart and is then easily broken 
away from the shell by finger pressure. The 
piece is glued onto a glass slide for thin- 
sectioning, which usually takes less than 15 
minutes and results in about a 0.25-mm-thick 
slice. Age lines in the thin section are translu- 
cent when viewed with transmitted light; 
growth increments between the lines are 
opaque. In photographic enlargements the 
translucent lines appear as dark lines and are 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 55 




FIG. 2. Photographic enlargements of thin-sectioned chon- 
drophores from surf clams: (a) 8 years old and 139 mm in 
shell length; and (b) 13 years old and 137 mm in shell length. 
The first annulus formed in the life of a surf clam is some- 
times faint (an arrow points to a bold one in the chondro- 
phore of clam a). The most recent annulus at the marginal 
edge of these chondrophores was not completely formed. 

the annuli (Fig. 2). Linear measurements from 
the umbo to growth bands in the chondrophore 
regressed upon the valve length of correspond- 
ing external bands for a sample of surf clams, 
using least squares technique, resulted in a 
relatively high correlation coefficient (r=0.97). 
The regression equation (y = 22.739 + 59. 063x) 
accounted for 94% of the variation between the 
two measurements. Thus, annuli in the chondro- 
phores of surf clams correspond in number and 
relative location with those in the valve. This 
refinement of the basic method of exposing in- 
ternal age lines in surf clams produces consis- 
tent age determinations, measurements of 
growth throughout the life of a clam, and 
records for future reference. 

Ocean Quahog Method 

Age determinations of ocean quahogs were 
significantly advanced by the recommendations 
of Thompson et al. (1980a and b) and Jones 
(1980) that the acetate peel technique be used. 
In the technique developed at the NEFC, Woods 
Hole Laboratory, left valves are routinely used 
because they have a unique, single tooth con- 
taining valuable age information useful in con- 
firming counts made from the valve. The steps 
in preparing valves include sectioning (Fig. 2), 
bleaching to remove the thick periostracum, 
embedding in epoxy, polishing, and etching the 
cut surface with a 1% HC1 solution (Ropes 1982). 
Then sheet acetate is applied with acetone to 



melt the acetate and peel off after the acetone 
completely evaporates. Except for the one 
minute etching period, the sectioning (15-30 
min), embedding (overnight hardening), polish- 
ing (2-3 hr) and drying (1 hr) periods are time 
consuming. The production of a peel is neces- 
sary, since the thin age annuli are microscopi- 
cally indistinct on the external valve surface or 
in the cut surface of an ocean quahog shell. 

Although age annuli and growth increments 
are reproduced much more clearly in a peel than 
in the cut surface of the shell, it must be exa- 
mined microscopically and the many crowded 
annuli in old quahogs are a challenge to count. It 
is not unusual to have quahogs that are about 
100 years old. 

Various experimental evidence suggests that 
annuli are formed in the shells of ocean quahogs 
(Thompson et al. 1980a and b, Jones 1980) in- 
cluding the use of radiometric techniques 
(Turekian et al. 1982, Bennett et al. 1982). A 
NMFS marking experiment substantially sup- 
ported such a hypothesis. Specimens were 
marked for release and recapture at a 53 m deep 
site off Shinnecock Inlet, Long Island, NY. The 
marks were made by two carborundum discs 
spaced 2 mm apart and mounted on an electric 
grinder. This produced distinctive parallel 
grooves at the ventral edge of about 42,000 
clams released in 1978. Marked quahogs have 
been recovered annually thereafter. 

Murawski et al. (1982) developed a growth 
rate relationship for marked ocean quahogs 
(59-104 mm in shell length) recaptured one year 
after release (SL, + , = 2.081 1 + 0.9802 SL,). Back- 
calculated growth measurements at age of un- 
marked quahogs (19-60 mm in shell length) cap- 
tured in the vicinity of the marking site resulted 
in an age/growth relationship for younger, 
smaller specimens [SL = 75.68-81.31 (0.9056)']. 
Growth in length described by these equations 
provided additional evidence for the growth rate 
of the species at the Long Island site. 

Ropes et al (in press) found definite prismatic 
microstructures, considered to be the basis for 
the formation of annuli, that separated growth 
increments of predominantly homogenous mi- 
crostructures. Although the microstructures are 
only visible by scanning electron microscopy, 
light microscope examinations of acetate peels 



56 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 




FIG. 3. Photomicrographs of acetate peels showing growth 
and annuli at the valve margins of ocean quahogs marked for 
release off Long Island, NY, in 1978 and recovered two 
years later, (a) a 15-year-old, 60 mm in shell length clam, and 
(b) a 95-year-old, 92 mm in shell length clam. An arrow 
points to an annulus formed soon after marking. Only one 
additional annulus was formed thereafter by both clams, and 
it separated two increments of shell growth accreted after 
marking. The flattened area in (b) was produced by the 
notching operation. 



clearly revealed the annual periodicity of annuli 
in small and large marked quahogs (Fig. 3). 

General Comments 

The growth of ocean quahogs is characteris- 
tically slow except during the first 20 years of 
life (Fig. 4). Quahogs of about 100 mm in shell 
length are about 100 years of age and are com- 
mon in the population. Maximum shell length 
approaches 140 mm, but large size may not in- 
dicate very old age (Ropes and Murawski 1983). 
A specimen 107 mm long has been found to have 
a minimum of 221 growth lines in its valve and it 
was alive when caught. A longevity of at least 
225 years surpasses known estimates for other 
bivalves. Ropes and Pyoas (1982) found evi- 
dence for geographic variation in the growth of 
ocean quahogs. Quahogs from Georges Bank 
were younger than specimens of equal length 
from off Long Island, NY, or off Sable Island, 
Canada. In a comparison of growth data for 
Georges Hank quahogs with marked quahogs 
from off Long Island, a much slower rate was 



<J3 

s 




150 



100 - 






2 


4 


6 


8 


10 12 14 16 


18 


20 


75 


















50 


















25 












Arclica islandico 











I 


< 


I 


i 


I 1 I I 


l 


i 



10 20 



v 



40 50 60 70 
AGE (YEARS) 



80 90 100 



FIG. 4. General age (in years) and growth relationship for 
surf clams (Spisula solidissima) (Ropes 1980) and ocean 
quahogs (Arrhrn islinnlira) ( Murau ski rt nl. 1982). 



obtained for the latter area. Ocean quahogs ap- 
pear to be reproductively viable throughout the 
long life span (Thompson et al. 1980a). Ocean 
quahog growth contrasts sharply with the faster 
growing surf clam. It commonly attains a shell 
length of about 165 mm in 10 years (Ropes 
1980). The maximum recorded shell length of a 
surf clam is 226 mm and longevity is estimated 
to be about 35 years. Growth lines similar to 
those in S. solidissima were found in Stimpson's 
surf clam, S. polynyma, another species in the 
family Mactridae. This suggests that the method 
of preparing surf clams for ageing may have ap- 
plication for other species with well developed 
chondrophores. Surf clams are probably also 
reproductive throughout their life span. Spawn- 
ing has been implicated as the possible stimulus 
for deposition of growth lines in both species 



Vol. 99 (2-3) 



April 29, 1985 



THE NAUTILUS 57 



(Thompson et al. 1980a, Jones et al. 1978). 

Population assessment studies integrate age- 
ing of large numbers of specimens throughout 
the extensive distribution of both species in the 
Middle Atlantic Bight and off New England. 
Samples of surf clam shells for age analysis are 
routinely taken during annual surveys of the 
resource in the Middle Atlantic Bight and off 
New England. The refined method serves effi- 
ciently in processing the samples collected dur- 
ing a survey without sacrificing accuracy of age 
determinations. The age data provide valuable 
information on growth rates and age composi- 
tion in assessment studies of this important 
commercial bivalve. The collection of similar 
data for ocean quahogs is thwarted by the labor 
intensive nature of shell preparation and micro- 
scopic examination. Nevertheless, ocean quahog 
samples from localized areas are under in- 
vestigation to gain insight into the age/growth 
phenomena. Age data are an integral part of 
management plans regulating both resources 
that have been developed by the Mid-Atlantic 
Fishery Management Council. 

LITERATURE CITED 

Ambrose, W. G., Jr., D. S. Jones and I. Thompson. 1980. 
Distance from shore and growth rate of the suspension 
feeding bivalve, Spisula solidissima. Proc. Natl. Shellfish. 
Assoc. 70:207-215. 

Arthur, M. A., D. F. Williams and D. S. Jones. 1983. Sea- 
sonal temperature-salinity changes and thermocline 
development in the Mid- Atlantic Bight as recorded by the 
isotopic composition of bivalves. Geol. 11:655-659. 

Bennett, J. T., K. K. Turekian. W. J. Shaul and J. W. Ropes. 
1982. Using natural radionuclides to measure shell growth 
rates and ages of the bivalves Arctica islandica (Linne) 
and Panope generosa Gould. Abstracts, 1981 An. Meeting, 
Natl. Shellfish Assoc, hi: Jour. Shellfish Res. 2:88-89. 

Jones, D. S. 1980. Annual cycle of shell growth increment 
formation in two continental shelf bivalves and its paleo- 
eeologic significance. Paleobiol. 6:331-340. 

1981a. Repeating layers in the molluscan shell 

are not always periodic. Jour. Pcdeont. 55:1076-1082. 

1981b. Annual growth increments in shells of 



Spisula solidissima record marine temperature variabil- 
ity. Science 211(4478):165-167. 
1983. Sclerochronology: Reading the record of 



the molluscan shell. Amer. Sci. 71:384-391. 

Jones, D. S., I. Thompson and W. Ambrose. 1978. Age and 
growth rate determinations for the Atlantic surf clam, 
Spisula solidissima (Bivalvia: Mactracea), based on in- 
ternal growth lines in shell cross-sections. Mar. Biol. 
47:63-70. 

Jones, D. S., D. F. Williams and M. A. Arthur. 1983. Growth 
history of Spisula solidissima Dillwyn as revealed by 
oxygen isotopes and sclerochronology. Abstracts, 1981 
An. Meeting, Natl. Shellfish. Assoc. In: Jour. Shellfish 
Res. 2:99. 

Lutz, R. A. and D. C. Rhoads. 1980. Growth patterns within 
the molluscan shell, an overview. In: Rhoads, D. C. and 
R. A. Lutz (eds), Skeletal Growth of Aquatic Organisms. 
Plenum Press, N.Y. 750 p. 

Murawski, S. A., J. W. Ropes and F. M. Serchuk. 1982. 
Growth of the ocean quahog, Arctica islandica, in the 
Middle Atlantic Bight. Fish. Bull. 80:21-34. 

Ropes, J. W. 1980. Biological and fisheries data on the 
Atlantic surf clam, Spisula solidissima Dillwyn. U.S. 
Dept. Comm... NOAA. NMFS. Tech. Ser. Rep. No. 24. 88 p. 

1982. Procedures for preparing acetate peels of 

embedded valves of Arctica islandica for ageing. U.S. 
Dept. Comm... NOAA. NMFS. NEFC. Woods Hole Labora- 
tory Ref Doc. No. 82-18. 8 p. 

Ropes, J. W. and A. S. Merrill. 1970. Marking surf clams. 
Proc. Natl. Shellfish. Assoc. 60:99-106. 

Ropes, J. W. and L. O'Brien. 1979. A unique method of 
ageing surf clams. Bull. Amer. Malacological Union. Inc., 
p. 58-61. 

Ropes, J. W. and D. Pyoas. Preliminary age and growth 
observations of ocean quahogs, Arctica islandica Linne, 
from Georges Bank. ICES/C.M. 1982/K:15, Shellfish 
Comm., 6 p. 

Ropes. J. W. and S. A. Murawski. 1983. Maximum shell 
length and longevity in ocean quahogs, Arctica islandica 
Linne. ICES/C.M. 1983/K:32, Shellfish Comm., 8 p. 

Ropes, J. W., D. S. Jones, S. A. Murawski, F. M. Serchuk 
and A. Jearld, Jr. Documentation of annual growth lines 
in ocean quahogs, Arctica islandica Linne. Fish. Bull. 
(In Press). 

Thompson, I., D. S. Jones and D. Deribelbis. 1980a. Annual 
internal growth banding and life history of the ocean 
quahog Arctica islandica (Mollusca: Bivalvia). Mar. Biol. 
57:25-34. 

Thompson, I., D. S. Jones and J. W. Ropes. 1980b. Advanced 
age for sexual maturity in the ocean quahog Arctica 
islandica (Mollusca: Bivalvia). Mar. Biol. 57:35-39. 

Turekian, K. K.. J. K. Cochran, Y. Nozaki, I. Thompson 
and D. S. Jones. 1982. Determination of shell deposition 
rates of Arctica islandica from the New York Bight using 
natural — 8 Ra and 228 Th and bomb-produced 14 C. Limnnl. 
Oceanogr. 27:737-741. 



58 THE NAUTILUS 



April 29, 1985 



Vol. 99 (2-3) 



TWO NEW SPECIES OF FAVARTIA FROM THE WEST 
PACIFIC OCEAN (GASTROPODA: MURICIDAE) 



Anthony D'Attilio and Barbara W. Myers 

Department of Marine Invertebrates 

San Diego Natural History Museum 

San Diego, CA 92101 

ABSTRACT 

Two new species ofmuricids, Favartia (Murexiella) rosamiae and F. (M.) leonae 
are described from the Philippines and Ryukyu Islands, and compared with 
related species. 



Through the courtesy of several shell collec- 
tors, we have recently obtained for the collec- 
tion of the San Diego Natural History Museum, 
specimens of two undescribed species of muricid 
gastropods. One of the new species, Favartia 
(Murexiella) rosamiae has been confused with F. 
cyclostoma (Sowerby, 1841). The redescription 
of F. cyclostoma and selection of a lectotype was 
discussed by D'Attilio and Myers (1984). 

Institutional abbreviations used in this paper 
are: AMNH = American Museum of Natural His- 
tory, New York, New York, and SDNHM = San 
Diego Natural History Museum, San Diego, 
California. 



I '.)71 



spire 



MURICIDAE Rafinesque, 1815 
MURICOPSINAE Radwin and D'Attilio, 
Genus Favartia Jousseaume, 1880 

Subgenus Murexiella 
Clench and Perez Farfante, 1945 
Favartia (Murexiella) rosamiae 
new species 
Figs, l to 6 
Shell moderately broad, fusiform; 
elongate; five to six postnuclear whorls; 
shoulder angulate on spire; suture impressed. 
Protoconch of holotype eroded; protoconch of 
paratype B with three and one-quarter conical 
transparent whorls. Aperture subovate; outer 
lip crenulate and fluted; inner lip moderately 
erect anteriorly. Anal sulcus weakly defined. 
Siphonal canal long, narrowly open, broad 
above, tapering terminally, recurved and tube- 
like. Two to four well-preserved former canal 
terminations on the siphonal fasciole. Four 
varices on body whorl, five on penultimate 




FIGS. 1 and 2. Favartia (Murexiella) rosamiae D'Attilio and 
Myers. Dorsal (1) and apertural (2) views of holotype. 
Dimensions 17.7 mmxl2.2 mm. SDNHM 80742. 

KKIS, :-; and 4. Fnnirtiti (Murrxielln) rusamiae D'Attilio 
and Myers. Dorsal (3) and apertural (4) views of paratype A. 
Dimensions 15 mmx 10.7 mm. SDNHM 85101. 



whorl; body whorl varices thick, beginning at 
suture above shoulder and descending anterior- 
ly to the canal. Spiral sculpture consisting of six 
strong cords terminating in spines; one or two 
cords above the shoulder, the strongest cord and 
spine at the shoulder and three secondary cords 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 59 




FIG. 5. Camera lucida drawing of the protoconch of F. (M.) 
rosamiae, paratype B. SDNHM 82288. Greatly enlarged. 





FIG. 6. Detail drawing of the radula of 
F. (M.) rosamiae. Greatly enlarged. 

below. Two additional cords on the canal. Cords 
separated on the dorsal side by a strongly 
depressed or excavated area. Cords covered by 
blunt appressed scales; a portion of each scale 
bulges beyond the width of the cord lending the 
cord a toothed or serrated appearance on both 
anterior and posterior sides. Cords and spines 
on the outer lip connected by a flange and the 
spiny extension of the spiral cords terminate 
well beyond the flange. Intervarical areas on the 
body whorl broadest between the final varix and 
the preceeding one. The scabrous cords strong 
on the varices and obsolete on the final inter- 
varical area. Cords and scales microscopically 



spirally grooved with the terminal portion of the 
scales convexly scalloped. The radula ribbon 
long and narrow with about 110 rows of teeth. 
The rachidian plate with five strongly project- 
ing, stocky short cusps, the central cusp extend- 
ing above the rachidian plate. 

Color: Holotype-dull white with four narrow 
brown bands visible within the aperture; 
siphonal canal a pale-orange. Color variability 
noted as follows: creamy white to tan occa- 
sionally with broad brown or red bands exterior- 
ly. The siphonal canal either white or tan, occa- 
sionally orange or deep coral-red. 

Type Locality: Cebu, Bohol Straits, Philippine 
Islands, 75-100 meters depth. Paratypes from 
Balut Island, Mindanao, Philippine Islands; 
Cebu, Bohol Straits, Philippine Islands; 
Okinawa, Ryukyu Islands, Japan. Collected in 
1984,. 

Dimensions: Holotype 17.7 mm in length, 
width 12.2 mm from Cebu, Bohol Straits, Philip- 
pine Islands (SDNHM 80742); paratype A, 15 
mm x 10.7 mm from Okinawa, Ryukyu Islands, 
Japan (SDNHM 85101); paratype B. 8.8 mmx 
6.2 mm from Cebu, Bohol Straits, Philippine 
Islands (SDNHM 82288). Seven paratypes from 
Cebu, Bohol Straits, Philippine Islands 
(SDNHM 80742) with the following measure- 
ments: 13.5 mmx 10.4 mm; 13.8 mmx9.0 mm; 

13.4 mmx 9.7 mm; 12.1 mmx 8.0 mm; 10.5 mm 
x7.3 mm; 10.2 mmx 7.3 mm; 9.5 mmx 6.2 mm. 
Twelve paratypes from Okinawa, Japan 
(SDNHM 81639) with the following measure- 
ments: 15.7 mmx 11.3 mm; 13.4 mmx9.8 mm; 
12.1 mmx9.0 mm; 12.4 mmx8.5 mm; 11.1 mm 
x9.6mm; 12.1 mmx8.6mm; 11.6 mmx7.7 mm; 
11.3 mmx8.5 mm; 11.5 mmx7.1 mm; 11.5 
mmx7.7 mm; 10.6 mmx8.5 mm; 9.8 mmx7.6 
mm. Twelve paratypes from Balut Mindanao 
Island, Philippine Islands (SDNHM 84345) with 
the following measurements: 12.3 mmx 8.4 mm; 
12.7 mmx7.5 mm; 12.5 mmx8.3 mm; 11.8 mm 
x 8.2 mm; 12.3 mmx 7.5 mm; 11.5 mmx 8.3 mm; 

11.5 mmx8.4 mm; 11.3 mmx8.0 mm; 10.7 mm 
x 7.6 mm; 10.8 mmx 7.7 mm; 11.3 mmx 7.5 mm; 
11.3 mmx8.5 mm. 

Two paratypes from Cebu, Bohol Straits, 
Philippine Islands are deposited in the American 
Museum of Natural History (AMNH 213556). 
We are depositing two paratypes each in the 
following institutions: two paratypes in the 



60 THE NAUTILUS 



April 29, 1985 



Vol. 99 (2-3) 



Academy of Natural Sciences of Philadelphia, 
from Cebu, Bohol Straits, Philippine Islands, 
14.3 mm x 9.0 mm; 13.3 mm x 8.6 mm; two para- 
types in the U. S. National Museum, from Cebu, 
Bohol Straits, Philippine Islands 13.4 mm x 7.4 
mm; 10.7 mm x 8.8 mm; two paratypes in the 
Los Angeles County Museum from Balut, Min- 
danao Island, Philippine Islands 12.7 mm x 9.2 
mm; 12.1 mm x 8.1 mm; two paratypes in the 
British Museum (Natural History) from Balut, 
Mindanao Island, Philippine Islands 14.5 mm 
x 11.0 mm; 12.5 mmx9.2 mm. 

Etymology: This species is named for Rose 
D'Attilio, wife of the senior author, who first in- 
troduced him to seashells by sending him a box 
of shells from Florida in 1938. The Italian "rosa 
mia", which means my Rose, is latinized into the 
genitive form ending. 

Discussion: Comparison is made with Favar- 
tia cirrosa (Hinds, 1844), the shell of which is 
broader with a shorter spire and possesses num- 
erous strong lirations within the aperture; the 
varices are sharply recurved and number six on 
the body whorl, eight on the penultimate whorl, 
and nine on the whorl preceding the penultimate 
whorl. This increase in the number of varices on 
the moderately short spire tends to obscure the 
suture. The spire is higher and better defined in 
F. rosamiae, and the varices on the body whorl 
number four or five. The protoconch of F. cir- 
rosa consists of two and one-half whorls, both 
whorls being the same diameter, while the pro- 
toconch of F. rosamiae consists of three and 
one-quarter smooth conical transparent whorls. 
For further discussion ofF. cirrosa, a rare, long 
poorly-known species, see D'Attilio (1981). 

This new species has been confused with F. 
cyclostoma (Sowerby, 1841). The well-defined 
characters of F. cyclostoma have been treated 
by D'Attilio and Myers (1984). Based on the 
morphology of the syntypic material, F. 
cyrloshiniti has a broader, heavier shell, the lee- 
i'ii\ |>,> iif w hirh measures 24 mm ■ 1 7 mm. 




FIGS. 7 and 8. Favartia (Murexiella) leonae D'Attilio and 
Myers. Dorsal (7) and apertural (8) views of holotype. 
Dimensions 14.2 mm x 11.5 mm. SDNHM 81638. 
FIGS. 9 and 10. Favartia (Murexiella) leonae D'Attilio and 
Myers. Dorsal (9) and apertural (10) views of paratype H. 
Dimensions 13.1 mmxl0.6 mm. SDNHM 85109. 




FIG. 11. Camera lueida drawing of the protoconch oIF. (M.) 
leonae paratype D. SDNHM 85105. Greatly enlarged. 



Favartia (Murexiella) leonae, new species 

Figs. 7 tn 1 1 

Shell broadly fusiform, shoulder angulate, 
spire moderately high, suture impressed. Proto- 
conch of holotype eroded; protoconch of para- 
type D with 2V4 dull white blunt, convex whorls; 
four to five postnuclear whorls. Aperture white. 



ovate; inner lip erect anteriorly. Anal sulcus 
directed to the left. Outer lip erect, crenulate, 
reflecting the exterior spiral sculpture. Siphonal 
canal broad above, narrowing and recurving 
distally, and weakly open. Siphonal fasciole with 
three scaly tubelike remnants of earlier canal 
terminations. Four varices on body whorl with 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 61 



the intervarical areas unequal. Five varices on 
penultimate whorl. Two weak spiral cords on 
spire strongly developed only on the back slope 
of the varix. Five to seven spiral cords on body 
whorl, weakly defined between varices and 
strongly developed on receding portion of the 
varices. The first two to three cords developing 
into elongate spines on the varices except on the 
apertural varix where all cords are of equal size. 
On the final varix the moderately projecting 
cords connected by a continuous flange which 
abuts the penultimate whorl. Growth striae on 
the body whorl weakly developed. The leading 
side of the apertural flange with about four to 
seven well developed lamellae in the interspaces 
between the cords. 

Color: Pale rose shell with spines a much 
lighter hue. Occasionally (holotype) with a broad 
band of deep coral red. 

Type locality: Bolo Point, Okinawa, Ryukyu 
Islands, Japan from 55 meters depth. Paratypes 
from Okinawa, Ryukyu Islands, Japan, and 
from Bohol Straits, Philippine Islands. 

Dimensions: Holotype 14.2 mm in length 11.5 
mm in width from Okinawa, Japan, (SDNHM 
81638); paratype A, 14.4 mm x 10.2 mm from 
Okinawa, Japan (SDNHM 85102); paratype B, 
10.7 mm x 8.6 mm from Okinawa, Japan 
(AMNH 213555); paratype C, 12.5 mm x 8.7 mm 
from Okinawa, Japan (SDNHM 85104); para- 
type D, 11.1 mmx7.8 mm from Bohol Straits, 
Philippine Islands, (SDNHM 85105); paratype 
E, 14.3 mmx 10.7 mm from Okinawa, Japan, 
(SDNHM 85106); paratype F, 14.2 mmx 11.0 
mm from Okinawa, Japan, (SDNHM 85107); 
paratype G, 14.0 mmx 9.8 mm from Okinawa, 
Japan, (SDNHM 85108); paratype H, 13.1 mm 
xl0.6 mm from Okinawa, Japan, (SDNHM 
85109); paratype I, 12.5 mmx 9.2 mm (SDNHM 
85110). 

Etymology: Named for Leona Bellin, wife of 
Phillip Bellin, who first collected specimens of 



Favartia (Murexiella) leonae from Okinawa, 
Ryukyu Islands, Japan, used in this study. 

IHscnssudi: This species bears little <'<>m- 
parison with any of its congeners, with the ex- 
ception of an unnamed species which is more 
widespread and of a larger size, under study at 
the present time from the western Pacific. The 
lack of shoulder spines on the apertural varix is 
a consistent character in the specimens studied. 

Acknowledgments 

We wish to thank the following friends who 
contributed specimens for our study: Phillip 
Bellin of Okinawa, Japan; Robert Yin of La 
Jolla, California; Donald Pisor of San Diego, 
California; Edward Swoboda of Los Angeles, 
California; Robert Foster and Charles Glass of 
Santa Barbara, California. We are grateful to 
David K. Mulliner for the photography used in 
this paper and Dr. Hans Bertsch for his 
assistance with the Latin orthography. Dr. 
William K. Emerson (AMNH) kindly reviewed 
the manuscript. 

LITERATURE CITED 

Clench, W. J. and I. Perez Farfante. 1945. The genus .1/// ru- 
in the western Atlantic. Johnsonia l(17):l-56, pis. 1-28. 

D'Attilio, A. 1981. The rediscovery of Murex cirrosus Hinds, 
1844. TheFestivus 13(4):46-51. figs. 1-8. 

DAttilio, A. and B. W. Myers. 1984. Redescription of Favar- 
tia cyclostoma (Sowerby, 1841) and selection of a lecto- 
type, with illustrations of some related species (Muricidae). 
TheFestivus 16 (11):116-122, figs. 1-12. 

Hinds, R. B. 1844. The Zoology of the Voyage of HMS 
Sulphur . . ., vol. II, 72 pp., 21 pis. 

Jousseaume. F. 1880. Division methodique de la famille des 
Purpurides. Le Natural iste 42:335-36. 

Radwin, G. E. and A. DAttilio. 1971. Muricacean supraspe- 
cific taxonomy based on the shell and the radula. The Echo 
4:55-67, 23 figs. 

Rafinesque, C. S. 1815. Analyse de la nature <m tableau de 
univers et des corps organises. Barravecchia, Palermo. 

Sowerby, G. B. II. 1841. Description of some new species of 
Murex, principally from the collection of H. Cuming Esq. 
1'roe. Zool. Sue. London for 184(1: 137-147. 



62 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



A RAPID METHOD FOR SLIDE MOUNTING OF MINUTE RADULAE, 

WITH 
A BIBLIOGRAPHY OF RADULA MOUNTING TECHNIQUES 



Paul S. Mikkelsen 

Department of Benthic Ecology 

Harbor Branch Foundation, Inc. 

R.R. 1, Box 196 

Ft. Pierce, FL 33450 



ABSTRACT 
A method for rapidly cleaning, staining and mounting many minute radulae is 
detailed through the use of many- chambered, deep-well slides, together with the use 
of CMC as a combined stain/mounting medium. A bibliography of literature on 
mounting radulae for both light and scanning electron microscopy is provided. 



Previous methods for preparing radulae have 
generally dealt with fairly large or macroscopic 
radulae. Most methods (e.g., Bowell, 1915; 
Gascoigne, 1975; Meeuse, 1950; Radwin, 1969) 
involve multiple handlings of the radula, i.e., 
cleaning, rinsing, possibly several steps of stain- 
ing, and bringing it up through a series of solu- 
tions prior to preparation for mounting. How- 
ever, these methods are inappropriate and time- 
consuming for extremely minute radulae, and 
most often result in their loss. 

The simplest methods for mounting very small 
radulae have been those accomplished on a 
single microscope slide. Such methods were sug- 
gested by Binney (1885:45), Beecher (1888:11), 
Verdcourt (1946), Meeuse (1950a:36), and later 
by Turner (1960), and Basch (1961). However, 
this procedure requires that each radula be pro- 
cessed individually and consecutively, requiring 
much time to process several radulae. 

The method described herein has two advan- 
tages: (1) many radulae can ber processed at 
nearly the same time, and (2) loss of extremely 
minute radulae is avoided by handling each 
radula only once, with the use of "CMC" (un- 
abbreviated spelling unknown) as both a stain 
and a mounting medium. Although use of CMC 
for mounting radulae is not new, it has ap- 
parently not been published, and is known pri- 
marily to more established malacologists. 
Advantages of the medium have been detailed 
for use with snail genitalia (Michelson, 1960), 
larval trematodes (Davis, 1964), and for larval 
chironomids (Beckett and Lewis, 1982). 



A bibliography of radula mounting techniques 
for both scanning electron and optical 
microscopy is provided. 

Materials and Methods 

CMC is a non-resinous, water-miscible mount- 
ing medium available from Masters Chemical 
Company, Inc., P.O. Box 2382, Des Plaines, Illi- 
nois 60018. Of the two types of mounting media 
offered, the faster-drying "CMC" series is highly 
preferable over the slower-drying "CMCP" 
series, for purposes described herein. The media 
may be obtained in a high or low viscosity state, 
with refractive indices ranging from 1.38-1.40 
(see E.P.A., 1980). The material is available 
pretinted with stain (aniline blue or acid fuchsin) 
or colorless, to which one can add his own stain 
if desired. 

To dissolve all soft tissue, the entire animal or 
only the odontophore of the animal (depending 
on specimen size) is soaked for a day in 5-10% 
NaOH placed in one marked well of a multi-well 
Boerner slide (available through American 
Scientific Products, 1430 Waukegan Rd., 
McGaw Park, Illinois 60085), or similar product. 
By utilizing all of the wells of the Boerner slide, 
many radulae can be prepared simultaneously. 
Heating to accelerate the dissolving process is 
disadvantageous because (1) excess heat may 
adversely affect the radular structure (see: 
Lindberg, 1977) and (2) high heat or boiling 
usually causes varying degrees of flocculent 
material to form in the NaOH, thus hindering 
the relocation of extremely small radulae. 



Vol. 99 (2-3) 



April 29, 1985 



THE NAUTILUS 63 



The Boerner slide is then placed in a container 
with a tight-fitting lid, into which has been 
placed a paper towel moistened with water, thus 
creating a humidity chamber which prevents the 
fluid in the Boerner slide from evaporating. The 
specimens are usually left to soak overnight, but 
may be left several days. Slight warming would 
accelerate the dissolving process. 

At the completion of the dissolving process, a 
radula is then located on the Boerner slide, 
using a dissecting microscope. A toothpick or 
other small probe is dipped into the stained 
CMC, removed, and the excess allowed to drip 
back into the bottle. The probe is then touched 
to a clean microscope slide to apply a very small 
portion (much less than a drop) of CMC. With an 
extremely fine dissecting needle type of probe in 
each hand, the radula is teased off the bottom of 
the well and brought to the surface. The radula 
is always manipulated by placing the probe(s) 
under the radula and lifting; the radula is never 
pinched with forceps or other tools. The micro- 
scope is pre-focused to the fluid surface, or re- 
adjusted if necessary. 

The radula is guided onto the upper surface of 
a submerged probe tip, using another probe as a 
guide. The radula is then lifted out of the NaOH 
and held stationary, directly above the well. The 
Boerner slide is moved aside, and the micro- 
scope slide is positioned such that the CMC on 
the slide is directly under the held radula, both 
within the field of view of the microscope. The 
radula and focus are lowered simultaneously 
such that one can see when the probe tip and 
radula contact the CMC. When contact is made, 
the second probe is used to ease the radula off 
the first probe, if necessary, and into the center 
of the CMC. 

At this point, the procedure varies somewhat 
for larger (but still small) radulae, and those 
which are extremely small: 

(A) With larger material and with the radula 
now in a very small amount of CMC, it can be 
manipulated, flattened, distorted, or dissected. 
As the CMC begins to set, the radula (or por- 
tions of it) can be placed in final position and 
allowed to dry until quite firm. Should the CMC 
begin to set prematurely, one has but to add a 
very slight amount of water to the preparation 
to gain more time. The CMC may turn slightly 
opaque, but should clear fairly rapidly. A full 



drop of stained CMC is then placed on the center 
of a clean cover slip which is picked up and in- 
verted to form a "hanging drop" of CMC on the 
underside of the slip. The slip is then very slowly 
(to avoid bubble formation) placed onto the slide 
and radula. As an alternative, additional CMC 
may be applied to the dry or nearly dry mount 
(to fill depressions in the set CMC) and the cover 
slip applied dry. 

(B) Very small radulae cannot be manipulated 
at this time, and should be kept wet (see below), 
in a somewhat larger drop of CMC. In this case, 
the cover slip may be applied dry, or with a 
hanging drop of additional CMC. As the CMC 
flows into position under the weight of the cover 
slip, the smaller radula (if allowed to remain 
wet) can be manipulated and kept toward the 
center of the cover slip by applying slight 
pressure on the edge of the cover slip toward 
which the radula is traveling. 

The radula is usually examined immediately, 
and the number of radular rows are usually 
counted at this time. Using low power of a com- 
pound microscope, the desired location and 
orientation of the still wet, smaller radula can be 
attained by slight pressure on the cover slip. Ex- 
treme pressure will cause the teeth to separate 
from the radular membrane (which is often 
desirable). Proper movement of the cover slip, 
and/or prior manipulation, can attain a final 
mount which has the radula partially folded over 
itself and/or twisted, possibly with several teeth 
dissociated from the radular membrane. This 
reveals many different angles of the teeth, and 
gives an observer the maximum information 
from a slide mount . . . much more than if the 
radula were simply flattened. The above mount- 
ing procedure is then repeated for the remain- 
ing radulae. Because the CMC does not dry 
rapidly, once the cover slip is applied, several 
radulae may be mounted on slides prior to ex- 
amination of them with a compound microscope; 
i.e., they can be processed in small groups to 
conserve time. 

With the radula in the proper position, and 
with all movement of the radula and CMC 
ceased, the slide is further examined with higher 
magnification and/or allowed to dry for about 24 
hours. At that time, the dried, excess CMC is 
trimmed away with the aid of a scalpel (a curved 
blade is preferable). Final cleaning is ac- 



64 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



complished by wiping with a moist, lint-free 
tissue. This trimming and cleaning is not only 
cosmetic, but also provides clean surfaces to 
allow a good "ringing" bond. The edge of the 
cover slip is then sealed or "ringed" with clear 
nail polish or other sutiable substance, twice, to 
insure a good seal such that the mounting 
medium will not evaporate. 

Stains 

Any suitable stain may be added to the color- 
less CMC. The more desirable stains used have 
been acid stains, Acid Fuchsin and Lignin Pink. 
Pronticil dye works well (pers. comm. Joseph 
Rosewater, 1984) and was used by Morrison 
(1951). These particular stains have stained the 
majority of the radula (many stains do not . . . 
and sometimes these do not), leaving unstained 
the tips of denticles of the older, enamelized 
teeth or the entire older tooth. The bases of the 
older teeth are often stained when the entire 
tooth will not pick up the stain. The desired 
stain may be added, in very small quantities, 
directly to the clear CMC. CMC may be pur- 
chased pretinted with acid fuchsin, but one may 
wish to alter (probably increase) the concentra- 
tion. Addition of enough acid fuchsin to attain a 
translucent, cherry color in the mounting 
medium is desirable. These acid stains, together 
with an extremely slight addition of a basic stain 
(especially methylene blue) to the CMC will 
usually stain the entire radula quite well, in- 
cluding older teeth and denticle tips. This com- 
bination of stains (fairly heavy on the acid stain 
and very light on the basic stain) maintains the 
one-step stain/mounting technique, as well as 
producing an entirely stained radula. 

The combination of stains mentioned above 
produces a radula of generally one color. For 
cases in which the radula is large enough to be 
handled with confidence, a dip in an appropriate 
acid stain dissolved in water, a water rinse, 
followed by a dip in an appropriate basic stain 
dissolved in water can produce a radula with the 
younger, chitinous teeth (and possibly older 
teeth and/or the bases of them) stained one 
color, while the older enamelized teeth are 
stained a second color (see Meeuse, 1950:29). 
From this point, the radula is given a final rinse 
in water and can immediately be mounted using 
the clear CMC. The effect of concentration and 



type of stain varies with the type of radula, and 
requires some experimentation to achieve the 
desired effect. 

Advantages 

Becuase a small radula can be placed directly 
from NaOH to the CMC stain/mounting medi- 
um, the method has the advantage of a single 
handling of minute radulae. This feature is 
essential with extremely minute radulae which 
are easily lost due to excessive handling. With 
acid fuchsin stain in the mounting medium, the 
radula is simultaneously stained and mounted; 
therefore, use of water soluble CMC eliminates 
rinsing the radula and carrying it through 
several solutions of an alcohol or alcohol/xylene 
series. 

Since some clearing action is provided by the 
CMC, the radula need not be completely clean of 
tissue in routine preparations. 

Disadvantages 

Due to the simple, quick-staining technique, 
the radula cannot be stained and destained to 
obtain the perfect density of staining. It also 
cannot undergo multiple stainings. However, 
this type of treatment is usually given to large 
radulae and generally cannot be accomplished 
with minute ones. 

The use of CMC for large radulae has been 
found to be undesirable because of the large 
distance required between the cover slip and the 
slide. Initially, such a mount seems normal, but 
with time large bubbles form under the cover 
slip. The ring of sealant around the cover slip 
usually separates, allowing moisture from the 
CMC to evaporate, which in turn allows the 
CMC to contract, pulling air bubbles in from the 
margins of the mount. Medium-sized, easily 
handled radulae may be mounted with CMC, but 
because of their size they may retain too much 
fluid to be placed directly into the mountant 
following removal from NaOH; a water wash 
may be required between these two steps. 

Acknowledgments 

The manuscript was reviewed by Drs. Joseph 
Rosewater, Richard S. Houbrick and Robert W. 
Virnstein. Their criticism is very much ap- 
preciated. 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 65 



BIBLIOGRAPHY 

Aboulafin, A. 1970. [preparation of radulae for microscopic 
observation and permanent mounting.] (in Yiddish) 
Argamon: Jour. Israel Malacolog. Soc. l(2):62-68. 

Baas Becking, L. G. M. and J. C. Chamberlain. 1925. A note 
on the refractive index of chitin. Proc. Soc. Exp. Biol. & 
Med. 22:256. 

Basch. P. F. 1961. A simple method for preparing radulae. 
Turtox news 39(1):46. 

Beckett. D. C. and P. A. Lewis. 1982. An efficient procedure 
for slide mounting of larval chironomids. Trans. Am. 
Micros. Soc. 101(l):96-99. 

Beecher, C. E. 1888. A method of preparing, for microscopi- 
cal study, the radulae of small species of Gasteropoda. 
Jour. N Y. Microscop. Soc. 3:7-11. 

Binney, W. G. 1885. A manual of American Land Shells. 
Washington; Government Printing Office; 528 pp. 

Bowell, E. W. 1915. On the mounting of radulae for micro- 
scopic examination. Proc. Malac. Soc. London 11(5): 
272-274; pi. 7. 

1924a. Radulae of Mollusca. J. Quekett Micro- 
scop. Club Series 2, 15, 57-64. 

. 1924b. The mounting of radulae for photomiero- 



mounts of radulae. Basteria 14(l-2):28-32; 14(3-4):33-43. 
1950b. Verborgen schoonheid. De Levende 



graphy. J. Roy. Microscop. Soc. 44:292-294. 

1928. A Review, The microscopy of radulae. J. 



Roy. Microscop. Soc. series 48 (part 2):161-177; pis. 1-4. 
Davis, G. M. 1964. A rapid method for mounting larval tre- 

matodes. Turtox News 42(1):40-41. 
Environmental Protection Agency. 1980. Macroinverte- 

brate mounting media. E. P. A. Newsletter, Quality 

Assurance 3(3): 1 pg. 
Fritchman, H. K., II. 1960. Preparation of radulae. Veliger 

3(2):52-53. 
Gascoigne, T. 1975. Methods of mounting Sacoglossan radu- 
lae. Microscopy 32:512-516. 
Glaugher, D. 1965. Preparation of the radula. Conch. Soc. 

Gr. Brit. & Ireland; Papers for students No. 5. 
Hickman, C. S. 1977. Integration of Electron scan and light 

imagery in study of molluscan radulae. Veliger 20(l):l-8. 
Knudsen, J. W. 1966. Biological techniques. Harper & Row, 

New York: xi + 525 pp; illust. 
Lindberg, D. R. 1977. Artifacts incurred by the treatment of 

acmaeid radulae with alkalies. Veliger 19(4):453-454. 
Marson, J. E. 1971. Making mounts in glycerine jelly. N.B.S. 

Booklet No. 2, Northern Biological Supplies, Ipswich. 
Meeuse, A. D. J. 1949a. De radula van slakken als micro- 

scopish object. Microwereld 4:677-684. 
1949b. Over de radula's van Mollusca. Corr.bl. 

Ned. Malac. Ver.. No. 34:274-277. 
1950. Rapid methods for obtaining permanent 



Natuur 53:9-15. 

Michelson, E. H. 1960. A rapid method for preparing mounts 
of snail genitalia. The Nautilus 74(l):32-33. 

Morris. T. E. and C. S. Hickman. 1981. A method for artifi- 
cially protracting gastropod radulae and a new model of 
radula function. Veliger 24(2):85-90. 

Morrison, J. P. E. 1951. How I prepare radulae. News 
Bulletin and Annual Report. American Malacological 
Union for 1950: 16-17. [Title inside front cover.] 

Pantin, C. F. A. and T. Rogers. 1925. An amphoteric sub- 
stance in the radula of the whelk (Buccinum undatum). 
Nature 115:639-640. 

Ploeger, S. and A. S. H. Breure. 1977. A rapid procedure for 
preparation of radulae for routine research with the scan- 
ning electron microscope. Basteria 41:47-52. 

Radwin, G. E. 1969. Technique for extraction and mounting 
of gastropod radulae. Veliger 12(1):143-144. 

Risso-Dominguez, C. J. 1961. The use of alkylene polyamines 
to isolate radulae. I. Reactions between effectiveness and 
chemical structure. Stain Technology 36(3):151-157. 

1964. The use of alkylene polyamines to isolate 

radulae. II. Practice and technique. Stain Technology 
39:195-204. 

Rogers, T. H. 1924. Electrical methods of staining the 
radulae of Mollusca. J. Roy. Microscop. Soc. 44:295-298. 

Runham, N. W. and P. R. Thornton. 1967. Mechanical wear 
of the gastropod radula: a scanning electron microscope 
study. J. Zooi. London 153:445-452. 

Schooley. C, C. S. Hickman and W. C. Lane. 1982. Com- 
puter graphic analysis of stereo micrographs as a tax- 
onomic tool. Veliger 24(3):205-207, 1 pi. 

Solem, A. 1972. Malacological applications of scanning elec- 
tron microscopy. II. Radular structure and functioning. 
Veliger 14:327-336. 

Solem, A. and J. L. van Goethem. 1974. Scanning electron 
microscope and optical microscope observations on 
urocyclid land snail radulae (Mollusca, Pulmonata, 
Urocyclidae). Bull. Inst. roy. Sci. nat. Belg.. Biologic 
50(70): 1-9. 

Thompson, T. E. and H. E. Hinton. 1968. Stereoscan micro- 
scope observations on opisthobranch radulae and shell 
sculpture. Bijdr. Dierk. 38:91-92. 
Turner, R. D. 1960. Mounting minute radulae. The Nautilus 
73(4):135-137. 

Verdcourt, B. 1946. An introduction to the study of radulae. 
The Microscope (London) 6:35-39. 

1948. The staining of radulae. Stain Technology 

23(3):145-149. 



66 THE NAUTILUS 



April 29, 1985 



Vol. 99 (2-3) 



SEDIMENT PREFERENCE OF THE FRESHWATER 
ASIATIC CLAM, CORBICULA FLUMINEA 

Scott E. Belanger, Jerry L. Farris, Donald S. Cherry, and John Cairns, Jr. 

Department of Biology and 

University Center for Environmental Studies 

Virginia Polytechnic Institute and State University 

Blacksburg, VA 24061 

ABSTRACT 

Corbicula fluminea, the Asiatic clam, occurs in well-oxygenated lotic systems in 
sediments of various compositions. This study reports on rigorously controlled 
studies o/Corbicula preferences of fine sand (predominantly between 0.25-0. 7 mm 
particle size), organically enriched fine sand (predominantly between 0.25-0.7 
mm particle size), coarse sand (predominantly 2.5-4.5 mm particle size), and no 
substrate in artificial streams in laboratory and field-laboratory settings using a 
paired choice design. In both the laboratory and field- laboratory, Corbicula 
preferred the sediments in the decreasing order of fine sand - organically enriched 
fine sand - coarse sand - no substrate. The density o/Corbicula at an industrially 
uninfluenced site in the New River was significantly greater in fine sand (452 
clams/m 2 with 70% of the sediment in the 0.35-0.60 mm particle size range) than 
coarse sand/gravel (177 clams/m 2 with 90% of the sediment in the 4.5-38.0 mm 
particle size range). The invasion of Corbicula into new habitats has been 
facilitated by the ability of the clam to utilize a wide variety of substrates, from 
fine sand to gravel. This study suggests that rivers with fine, well-oxygenated sand 
substrates would be optimal for establishment of Corbicula populations in newly 
colonized sites. 



Corbicula fluminea, the introduced Asiatic 
clam, is a species that flourishes in well-oxygen- 
ated lotic systems. In these habitats, C. flu- 
minea inhabits nearly all sediment types to 
varying degrees (Home and Mcintosh, 1979; 
Rodgers et al., 1979). Elimination or reduction 
of Corbicula. populations has been recorded in 
association with sediments of high organic and 
low oxygen content (Aldridge and McMahon, 
1978; McMahon, 1979; Eng, 1979). Respiration 
was shown by Dudgeon (1980) to be correlated 
inversely with mean particle size and perhaps 
related to increased metabolic demands of clams 
in fine substrates. 

Densities of Corbicula in North America are 
greatest in well-aerated sand or sand-gravel 
mixtures (McMahon, 1983). Corbicula became 
established in the New River in southwestern 
Virginia around 1977 (Rodgers et al, 1977). 
Graney et al. (1980) determined that Corbicula 
showed little discernible substrate preference 
within and outside a thermal discharge at the 



Glen Lyn Power Plant, Virginia, achieving max- 
imal densities of 11,522 clams/m 2 in the dis- 
charge (sand to sand-gravel) and 2,286/m 2 in 
uninfluenced regions of the river at the plant in 
fine sand to sand sediments. Upstream of the 
Glen Lyn Plant, establishment of Corbicula has 
required more time (e.g., ~3 years). Cherry et 
al. (in press) have documented clam densities of 
3, 397-23, 689/m 2 at an industrial pumphouse 
station (Celanese Fibers Corporation, Narrows, 
Virginia) 9.9 km upstream of the Glen Lyn 
Plant. This site is thermally uninfluenced and is 
characterized by well-oxygenated sediment with 
68% of the particles in the size range of 0.25- 
0.7 mm. 

Thus far, conventional wisdom of Corbicula 
distributional ecology has been that clams pre- 
fer coarse sand (1.5-2.5 mm) or mixed sand/ 
gravel (2.5-60 mm) based upon field sampling 
results. A combination of rigorously controlled 
preference studies in the laboratory, field- 
laboratory, or in field validation experiments 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 67 



has not been attempted. Objectives of the 
research herein were to determine the prefer- 
ence of adult Corbicula for distinct sediment 
size classes (0.2-40 mm) using a paired choice 
experimental design. Preference trials were 
performed in a formal laboratory artificial 
stream and field-laboratory setting and subse- 
quently validated by field sampling in the New 
River. 

Materials and Methods 

Laboratory Preference Study 

Preference trials were conducted in February, 
March, and April 1984 at the University Center 
for Environmental Studies Ecosystem Simula- 
tion Laboratory (ESL) at Virginia Polytechnic 
Institute and State University (Va Tech). Sedi- 
ment preference chambers were constructed 
using plexiglass (17.5x17.5x1.5 cm). Three 
chambers were placed in each of six artificial 
streams (Fig. 1; Farris et al., in review). The cir- 
cular artificial streams have a 20-1 capacity and 
are circulated by a gear-driven paddle wheel 
system to provide a uniform current flow similar 
to the river environment. Each stream received 
dechlorinated Blacksburg town tap water 
(water quality summarized in Table 1) at a flow 
rate of 300-400 ml/min which resulted in 21.6- 
27.0 turnovers per day. Water temperatures 
ranged from 10 to 17°C. Adult Asiatic clams 
(12-17 mm shell length) were obtained from the 
New River and acclimated to laboratory condi- 
tions for 5-7 days. Fine sand (72% between 
0.25-0.7 mm), organically enriched fine sand 



(72% between 0.25-0.7 mm), and coarse sand 
(83% between 2.5-9.0 mm) sediment types were 
chosen for testing in these experiments based 
on their suspected relevance to Corbicula in the 
New River (Graney et al, 1980). Fine sand was 
obtained in the New River near the Celanese 
Fibers Corporation and was sterilized prior to 
use by drying at 90°C for 24 hr and 500°C for 24 
hr. Organically enriched fine sand was prepared 
by freeze drying Elodea sp. and Nasturtium sp. 
(water cress) in liquid nitrogen, crushing the 
frozen material, and mixing the organic matter 
50:50 by volume (15:85 by weight) with sterilized 
fine sand. Coarse sand was obtained from a 
small fast flowing stream (Sinking Creek) near 
the Va Tech campus. Gravel was obtained from 
an aquarium supplier in Blacksburg. No 
substrate consisted of stacked 0.635 cm plexi- 
glass plates. 

For each preference trial, two substrates were 
placed side-by- side with a sharp, linear demarca- 
tion between them in each preference chamber 
(Fig. 1). Five adult clams were placed umbo 
down along the line of demarcation. Three repli- 
cates were used for each pair of sediments com- 
pared during the experiment: no substrate vs 
fine sand, no substrate vs organically enriched 
fine sand (hereafter referred to as "organic" in 
tables), no substrate vs coarse sand, fine sand vs 
organically enriched fine sand, fine sand vs 
coarse sand, and organically enriched fine sand 
vs coarse sand. Positions of the five Corbicula 
were traced for 7 days after preliminary prefer- 
ence trials of 3 weeks suggested this interval 



TABLE 1. Water quality parameters for the laboratory experiments (ESL), field- 
laboratory experiments (Glen Lyn), and field survey. The range is below the mean for each 
parameter in parentheses. Sample sizes are n = 2 for the ESL streams, river- fed streams at 
Glen Lyn, and for the field survey. 











Site 






ESL 








Parameter 




(Laboratory) 


Field-Laboratory 


McCoy, Virginia 


PH 




7.75 


8.25 




8.7 






(7.7-7.8) 


(7.8-8.7) 




(8.6-8.8) 


Temp (°C) 




14.0 


13.0 




18.5 






(10-17) 


(11-20) 




(15-22) 


Water Hardness 


57.5 


95 




90 


(mg/1 as 


CaC0 3 ) 


(55-60) 


(90-100) 




(90) 


Alkalinity 




27.0 


57.5 




53.5 


(mg/1 as 


CaC0 3 ) 


(26.0-28.0) 


(55-60) 




(50-57) 



68 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 




FIG. 1. Artificial stream system and plexiglass sediment 
preference chambers (P) used in laboratory substrate 
preference experiments at the Ecosystem Simulation 
Laboratory. Inflow water (arrow) is circulated bj a paddle 
wheel (W) attached to a single speed gear motor. 

was more than sufficient for clams to attain a 

final, permanent position in the preference 

chamber. 

Field-Laboratory Preference Study 

Sediment preference experiments were con- 
ducted in June, August, and October 1984 at a 
field-laboratory located at the Glen Lyn Power 
Plant adjacent to the New River. New River 
water was delivered from submerged pumps to 
4.6-m fish hatchery troughs at the rate of 4 1/min 
(see Clark et al, 1980). The depth of the water 
was maintained at 12-14 cm, resulting in 19.8- 
23.0 turnovers per day. Water temperatures 
ranged from 11 to 20° C. Plexiglass sediment 
preference chambers described earlier were 
placed on top of 8-cm platforms to minimize the 
potential of river silt settling onto the chambers. 
The experimental protocol used in the field- 
laboratory study was identical to the formal 
ESL study except all chambers and sediment 
preference trials were placed in one stream. The 
clams used for these studies were collected from 
the Celanese Fibers Corporation pumphouse in 
April and May 1984 and maintained in a hatch- 
ery trough at the Glen Lyn Plant. New River 
water quality for these experiments is sum- 
marized in Table 1. 
Field Sampling 

Estimates of the density of Corbicula were 
made on September 9 and December 18, 1984, 
in the New River at McCoy, Virginia. This site 



was chosen because: (1) it receives no industrial 
influence and, therefore, represents a natural 
Corbicula population in the New River, (2) the 
sampling region has several distinct substrate 
types relative to particle size in close proximity 
under nearly equal current regimes, and (3) ac- 
cessibility for sampling a 0.3-m water depth was 
advantageous for sampling gear. Density esti- 
mates were derived for two substrate types, fine 
sand and sand/gravel, by removing triplicate 
samples from each area with a Surber sampler 
(0.1 m 2 sampling area). Each sediment-clam 
sample was placed individually in buckets and 
returned to the laboratory for analysis. Clams 
were handpicked from each sample. Sediment 
was dried and sieved to determine sediment 
composition by weight using a Metier PC-440 
electronic balance (accuracy, ±0.0005 g). Adult 
(>8.0 mm shell length) and juvenile (~2. 5-8.0 
mm shell length) clams were measured for shell 
length by vernier calipers (accuracy, ±0.05 mm). 
Estimates of "larval" (veliger) density in each 
sample were made by analyzing the sediment 
fractions that were <2.5 mm from each 
replicate. 
Statistical Treatment of Data 

Preference experiments were analyzed by 
one-way analysis of variance (ANOVA) (Steel 
and Torrie, 1960) at each observation period and 
for each sediment pairing. For each pair of 
sediments, three possible outcomes were com- 
pared: (1) clams would reside in sediment A, (2) 
clams would reside in sediment B, or (3) clams 
would remain in the region of the demarcation 
between sediment A and sediment B. If a 
significant difference existed by the ANOVA 
F-test (a = 0.05), Duncan's Multiple Range Test 
was performed to determine which group(s) 
were significantly different (Steel and Torrie, 
1960). Results of Corbicula densities observed in 
the field in coarse and fine sediments were 
analyzed by the student's t-test. 

Results 

Laboratory Preference Study 

Corbicula were found to prefer any substrate 
(fine sand, organically enriched fine sand, or 
coarse sand) over no substrate at all (Table 2). 
Clams were observed to move rapidly into sedi- 
ments. After 1 hr, 70-80% of the clams were 
buried in the sediments offered. By the third 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 69 



TABLE 2. Analyses of variance for Corbicula sediment preference of fine sand versus no substrate, 
organically enriched fine sand versus no substrate, and coarse sand versus no substrate conducted at 
the Ecosystem Simulation Laboratory and Glen Lyn field laboratory. Means with the same letter are 
not significantly different (o = 0.05) using Duncan's Multiple Range Test. 





Substrate 




% Residence at Time 




Site 


F-ratio 
1 hr (p-value) 


F-ratio' 
Day 1 (p-value) 


Days 3-7 


ESL 


Fine 

No Substrate 

Uncommitted 


71. 1+31. 8 a 

4.4±8.8 
25.5+21.8 


97.8±6.7 a 

0±0 b 

2.2±6.7 a 


100.0+0 

0±0 
+ 




Organic- 
No Substrate 
Uncommitted 


82. 2+27. 3 a 

4.4±8.8 b 
13. 4+27. 9 b 


97.8±6.7 a 

0±0 b 

2.2±6.7 


100. 0±0 
+ 
+ 




Coarse 

No Substrate 

Uncommitted 


82.2127.0^ 
8.9±20.2 
8.9±14.5 


97.8+6.7 a 

2.2+6.7 b 

0±0 b 


100. 0±0 
+ 
+ 


Glen Lyn 


Fine 

No Substrate 

Uncommitted 


46. 7+46. 9 a 

2.2+6.2 b 
51. 2+46. 9 a 


100. 0±0 
0±0 
0±0 


100. 0±0 

+ 
0±0 




Organic 

No Substrate 

Uncommitted 


62.2±27.2 a 

2.2±6.7 b 
35.1±30.0 a 


100. 0±0 
0±0 
0+0 


100.0+0 
+ 
+ 




Coarse 

No Substrate 

Uncommitted 


46.7±24.5 a 

6.7+10.0 
46. 6+21. 9 a 


82.2±27.2 a 
"4.4 + 8.8 b 

13.4+12.7 


100. 0±0 
0±0 
0±0 



'All clams resided in the substrate from Day 3 to Day 7. Analyses of variance are not quoted since the 
data are unsuitable for this statistical method. 

2 Uncommitted clams were designated as those that did not move from the line of demarcation be- 
tween sediments. 



day, 100% of the clams were buried in all sedi- 
ments, and none remained exposed (Table 2). 

Clams consistently preferred fine sand or or- 
ganically enriched fine sand when coarse sand 
was the alternative choice (Table 3). The choice 
of fine sands was significant by Day 3 (Table 3), 
although, for fine sand alone, the choice was 
made sooner (on Day 1; Table 3). 

When clams were offered the choice of organi- 
cally enriched fine sand vs fine sand, the prefer- 
ence pattern was less distinct than for either of 
these sediments vs no substrate or coarse sand 
(Table 3). Ultimately, fine sand was significantly 
preferred over organically enriched fine sand 
(Days 6 and 7; Table 3). 
Field-Laboratory Preference Study 

Results of these preference trials were similar 
to experiments conducted at the ESL. Any 
substrate (e.g., fine sand, organically enriched 
fine sand, and coarse sand) was significantly 



preferred over no substrate at all (Table 4). By 
Day 3, all clams were buried in fine sand, organi- 
cally enriched fine sand, and coarse sand when 
no substrate was the alternative (Table 4). 

Clams did not prefer coarse sand when offered 
fine or organically enriched fine sand; however, 
fine sand was significantly preferred sooner 
(Day 1; Table 4) than organically enriched fine 
sand (Day 3; Table 4). By Day 7, 78% of the 
clams resided in fine sand when coarse sand was 
the alternative, and 71% resided in organically 
enriched fine sand when coarse sand was the 
alternative (Table 4). Preference trials of fine vs 
organically enriched fine sand showed clams 
preferred fine sand. By Day 5, 60% of the clams 
resided in fine sand substrate (Table 4). 
Field Sampling 

The density of Corbicula was two to three 
times greater in fine sand (75% of the sediment 
was in the 0.35-0.60 mm size range) than coarse 



70 THE NAUTILUS April 29, 1985 Vol. 99(2-3) 

TABLE 3. Analyses of variance and percent residence for Corbicula sediment preference experiments at the Ecosystem 
Simulation Laboratory. Means with the same letter are not significantly different (a = 0.05) using Duncan's Multiple Range 
Test. 









% Residence at 


Time 






Substrate 


1 hr 


Day 1 


Day 3 




Day 5 


Day 7 


Organic- 


40.0±30.0 


51. 1138. 8 a 


64. 4123. 4 a 




66. 7120. 7 a 


76.7115. I a 


Coarse 


26.7130.0 


a,b 
28.9124.5 


21.1117.8 




30. 0120. 9 b 


20. 011 7. 9 b 


Uncommitted 


33.3±30.0 


20.0121.1 


14.4±16.3 b 




3.318.2 C 


3.318.2° 


Fine 


32.2127.9 


62. 216. 7 3 


63. 3136. 7 a 




70.0116. 7 a 


70. 0127. 6 a 


Coarse 


27.8120.0 


24. 4116. 7 b 


6.7110.3 




13. 3116. 3 b 


23. 3129. 4 b 


Uncommitted 


47.8124.5 


13. 3117. 3 b 


30.3130. 3 a ' 


b 


16.7t8.1 b 


6.7116.3 


Fine 


24.4126.0 


64. 1127. 3 a 


37.0127.3 




70.0135. 2 a 


73. 3130. l a 


Organic 


47.7120.0 


31. 9114. 5 b 


37.0127. 3 




13. 3116. 3 b 


23. 3126. 6 b 


Uncommitted 


28.9128.4 


14. 1114. 1 C 


25.9123.3 




16.7119.7 


3.3l8.2 b 



F (and in parentheses, p-values) were 0.44 (0.6464); 2.71 (0.0866); 11.71 (0.0009); 19.50 (0.001); 
43.37 (0.0001) for time 1 hr through Day 7. 

F (and in parentheses, p-values) were 1.67 (0.2085); 28.50 (0.0001); 6.15 (0.0112); 29.67 (0.0001); 
10.25 (0.0016) for time 1 hr through Day 7. 

F (and in parentheses, p-values) were 1.98 (0.1605); 11.90 (0.0030); 0.48 (0.6245); 9.61 (0.0021); 
13.93 (0.0004) for time 1 hr through Day 7. 

TABLE 4. Analyses of variance and percent residence for Corbicula sediment preference experiments at Glen Lyn. Means 
with the same letter are not' significantly different (a = 0.05) using Duncan's Multiple Range Test. 









% Residence at Time 






Substrate 


1 hr 


Day 1 


Day 3 


Day 5 


Day 7 


Organic 


a,b 
35.6127.9 ' 


44. 4129. 6 a 


53. 3130. a 


60. 0122. 4 a 


71. 1117. 6 3 


Coarse 


15. 6126. b 


a,b 
40.0133.1 ' 


37. 8127. 2 a 


40. 0122. 4 b 


15. 6113. 3 b 


Uncommitted 


48. 9130. 2 a 


15. 6119. 4 b 


8.9120.2 


010 


4.4t8.8 b 


Fine 


26. 7117. 3 b 


60. 7120. a 


71. 1120. 3 a 


69.6128. 5 a 


77.8127. 3 a 


Coarse 


8.9110.5 C 


24. 4119. 4 b 
/ 

8.9tl4.5 b 


24. 4121. 9 b 


22.9121. l b 


22. 2127. 3 b 


Uncommitted 


64. 4113. 3 a 


4.418.8 C 


7.4114. l b 


o.o c 


Fine 


20. 0134. 6 a 


40.0117.3 


46. 7124. 5 3 


60.0114. I 3 


62. 2123. 3 a 


Organic 


17.8123. 3 a 


40.0124.5 


44. 4124. a 


37. 8115. 6 b 


33.3122.4 


Uncommitted 


62. 2139. 3 b 


20.0122.4 


13. 3122. 4 b 


2.216.7° 


4.4113.3° 



F (and in parentheses, p-values) were 3.24 (0.050); 2.78 (0.0825); 6.68 (0.0049); 25.20 (0.0001); 
60.78 (0.0001) for time 1 hr through Day 7. 

2 F (and in parentheses, p-values) were 36.91 (0.0001); 24.4 (0.0001); 32.69 (0.0001); 19.45 (0.0001); 
29.10 (0.0001) for time 1 hr through Day 7. 

F (and in parentheses, p-values) were 5.15 (0.0138); 2.57 (0.0973); 5.59 (0.0102); 46.91 (0.0001); 
18.44 (0.0001) for time 1 hr through Day 7. 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 71 



sand/gravel substrate (90% of the sediment was 
in the 4.50-36.00 mm size range) in the New 
River. Sediment composition of the December 
18 samples is summarized in Figure 2. The den- 
sities of adult and juvenile Corbicula were ap- 
proximately the same for both samples in the 
respective sediments (Table 5). After combining 
the results of both September 9 and December 
18 samples, a t-test indicated that the densities 
of the clams were significantly greater in the 
finer sand substrate than in coarse sand/gravel. 
These results are consistent and supportive of 



the laboratory and field-laboratory preference 
experiments. 

Discussion 

Sediment preferences of Corbicula were con- 
sistent in both laboratory and field-laboratory 
experiments. Although some temporal differ- 
ences existed for some comparisons, relative to 
where the experiment was performed (e.g., fine 
sand vs coarse sand, and fine sand vs organi- 
cally enriched sand), the preferences were ulti- 
mately identical (i.e., fine sand was preferred 



i 
o 



>- 



CO 

o 

5 

o 

o 



z 

LU 

O 
DC 

LU 

a. 

z 
< 



30 



20 



ja 



.H 



-S 



JS 



am 



Coarse Sand /Gravel 
Fine 



JOi 



L 



<0.10 0.11 0.26- 

0.25 0.35 



36 
0.50 



0.51 
0.60 



61 
0.70 



071- 
1.50 



151- 
2.50 



2.51 
4 50 



4.51- 9 51 18 01 
9.50 18.00 3600 



PARTICLE SIZE |mm| 

FIG. 2. Mean percent composition by weight of coarse sand/gravel samples and fine sand samples 
from the New River taken by Surber sampling for Corbicula densities. 



TABLE 5. Densities of larval (^1 mm), juvenile (1.0 to 8.0 mm) and adult Corbicula (>8.0 mm) within the New River at 
McCoy, Virginia. 



Collection 
Date 



Sediment 
Type 



Larval 

Density t-test 

( individuals/m 2 ) {p-value) 



Juvenile/Adult 

Density 
(individuals/m 2 



t-test Shell length 
(p-value) (Means±SD) 



t-test 
(p-value) 



9 Sept 1984 


Fine sand 


3 


— 




Coarse 


3 


-- 




Sand/ 








gravel 






18 Dec 1984 


Fine sand 


3 


14.3 ± 6.51 




Coarse 


3 


14.37 ± 16.38 




sand/ 








gravel 






Combined 


Fine sand 


6 


— 




Coarse 


6 







sand/ 








gravel 







398 


1 ± 376.6 






10 


28 


* 


2 


34 


123 






139 


8 ± 59.9 


1 
(0 


173 
3580) 


10 


52 


t 


3 


83 


39 



(0 


4091 
6831) 


505 


72 + 67.2 






11 


08 


+ 


3 


16 


141 






215 


2 i 32.3 


6 

(0 


750 
0084) 


11 


69 


i 


2 


46 


50 


1 

(0 


3237 
1871) 


451 


9 ± 24.90 






10 


71 


+ 


2 


83 


264 






177 


5 ± 59.6 


2 
(0 


625 
0425) 


11 


3 5 


+ 


2 


•• 


B9 


1 

(0 


799 
0729) 



72 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



for the aforementioned comparisons). Thus, it 
was possible to rank the observed experimental- 
ly identified preferences to predict the sites/ 
substrates of varying densities of clams located 
in the field. The preferences observed in these 
studies were in the following descending order: 
fine sand - organically enriched fine sand - 
coarse sand - no substrate. The field sampling, 
which found clams to be significantly denser in 
the fine sand than coarse sand/gravel under 
similar environmental conditions of current, 
temperature, light, and season, corroborated 
our predictions in this study. 

The importance of sediment to population 
dynamics and success of Corbicula invasion has 
been previously emphasized by several investi- 
gators. Eng(1979) discussed the use of incrusta- 
ceans along the Delta- Mendota concrete canal 
by Corbicula as a nursery zone and refuge for 
larvae and small juveniles. Sickel and Burbank 
(1974) investigated preferences of newly re- 
leased juveniles for substrates and found coarse 
sand was preferred over mud (potentially 
oxygen-limiting) or bare concrete (ecologically 
barren surface). McMahon (1983) suggested that 
flourishing Corbicula populations in streams 
that are canalized may optimize the environ- 
ment for this species by eliminating the reduc- 
ing environments of mud and silt under fast 
flowing conditions. The importance of thermal 
inputs from power plants and other industrial 
installations has been documented previously by 
several investigators (Rodgers et al., 1977; 
McMahon, 1977; Scott- Wasilk et al, 1983). 
Graney et al. (1980) surveyed Corbicula popula- 
tions at the Glen Lyn Power Plant in thermally 
influenced and uninfluenced stations with vari- 
ous substrate compositions and concluded that 
thermal discharges had a greater influence upon 
clam survivorship and density than substrate 
composition. It is important to note that ther- 
mal effluents allow clams to sustain reproducing 
populations over the winter where they would 
otherwise not occur (Graney et al., 1980; Scott- 
Wasilk et al., 1983; McMahon, 1982). 

Corbicula has continued to invade new habi- 
tats in North America and is now found in near- 
ly every state in the continental United States 
(McMahon, 1982). The ability of Corbicula to 
utilize a wide variety of substrates, from fine 
sand to gravel (which Corbicula finds inhabit- 



able), has enhanced its success. However, this 
study suggests that rivers with fine, well oxy- 
genated sand substrates would be optimal for 
establishment of Corbicula populations in newly 
colonized sites. 

LITERATURE CITED 

Aldridge, D. W. and R. F. McMahon. 1978. Growth, fecund- 
ity, and bioenergetics in a natural population of the fresh- 
water clam, Corbicula manileyisis Phillippi, from North 
Central Texas. Jour. Mollusc. Studies 44:49-70. 

Cherry, D. S., R. L. Roy, R. A. Lechleitner, P. A. Dunhardt, 
G. T. Peters and J. Cairns, Jr. In Press. Corbicula invasion 
in the New River: fouling and control measures at the 
Celco Plant, Virginia. In Proceedings of the 1983 Second 
International Corbicula Symposium. Little Rock, 
Arkansas. 

Clark, J. R., J. H. Rodgers, Jr., K. L. Dickson and J. Cairns, 
Jr. 1980. Using artificial streams to evaluate perturbation 
effects on aufwuchs structure and function. Water 
Resourc. Bull 16:100-104. 

Dudgeon, D. 1980. A comparative study of the Corbiculidae 
of Southern China. In B. Morton (editor) The Malaco- 
fauna of Hong Kong and Southern China. Hong Kong 
University Press, Hong Kong. p. 37-60. 

Eng, L. L. 1979. Population dynamics of the Asiatic clam, 
Corbicula fluminea (Miiller), in the concrete-lined Delta- 
Mendota canal of central California. In J. C. Britton 
(editor) Proceedings of the First International Corbicula 
Symposium. Texas Christian University, Fort Worth. 
Texas, p. 39-68. 

Graney, R. L., D. S. Cherry, J. H. Rodgers, Jr. and J. Cairns, 
Jr. 1980. The influence of thermal discharges and sub- 
strate composition on the population structure and distri- 
bution of the Asiatic clam, Corbicula fluminea, in the New 
River, Virginia. The Nautilus 94:130-135. 

Home, F. R. and S. Mcintosh. 1979. Factors influencing 
distribution of mussels in the Blanco River of Central 
Texas. The Nautilus 93:119-133. 

McMahon, R. F. 1977. Shell size-frequency distribution of 
Corbicula manilensis Philippi from a clam-foaled steam 
condenser. The Nautilus 91:54-59. 

1979. Response to temperature and hypoxia in 

the oxygen consumption of the introduced Asiatic fresh- 
water clam Corbicula fluminea (Muller). Camp. Biochem. 
Physiol. 63A:383-388. 

1982. The occurrence and spread of the intro- 



duced Asiatic freshwater clam, Corbicula fluminea 
(Muller), in North America: 1924-1982. The Nautilus 
96:134-141. 

1983. Ecology of the invasive pest bivalve 



Corbicula. In W. D. Russel-Hunter (editor) Tin Mollusca: 

Ecology. Vol. 6. Academic Press, Inc., New York. 

p. 505-562. 
Rodgers. J. H.. Jr.. D. S. Cherry, J. R. Clark. K. L. Dickson 

and J. Cairns, Jr. 1977. The invasion of Asiatic clam, 

Corbicula manilensis. in the New River. Virginia Tin 

Nautilus 91:43-46. 
Rodgers, J. H.. Jr., D. S. Cherry, K. L. Dickson and J. 

Cairns, Jr. 1979. Invasion, population dynamics and ele- 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 73 



mental accumulation of Corbicula fluminea in the New 
River at Glen Lyn, Virginia. In J. C. Britton (editor) 
Proceedings of the First International Corbicula Sympo- 
sium. Texas Christian University, Fort Worth, Texas, 
pp. 99-110. 
Scott-Wasilk, J., G. G. Downing and J. S. Leitzow. 1983. 
Occurrence of the Asiatic clam Corbicula fluminea in the 
Maumee River and Western Lake Erie. Journ. Great 



Lakes Res. 9:9-13. 

Sickel, J. B. and W. D. Burbank. 1974. Bottom substratum 
preference of Corbicula manilensis (Pelecypoda) in the 
Altamoha River, Georgia. Assoc. Southeastern Biol. Bull. 
21:84. 

Steel, R. G. D. and J. H. Torrie. 1960. Principles and Pro- 
cedures of Statistics with Special References to the 
Biological Sciences. McGraw-Hill, New York. 481 p. 



A WEST INDIAN COLUMBELLID NEW TO THE 
GENUS STEIRONEPION 



C. John Finlay 

1024 Daytona Dr. NE 
Palm Bay, FL 32905 

ABSTRACT 

In 1850 C. B. Adams described Pleurotoma maculata from Jamaica. Subse- 
quent beach specimens from Varadero Beach, Cuba, and the Bahamas, as well as 
examples from dredged sand at Marianao, Havana, Cuba (described as Turri- 
jaumelia jaumei Sarasila, 1975), further extend, the known range. A morphological 
assessment would suggest that the species be placed in the columbellid genus 
Steironepion, thus adding a third species to that genus from the Caribbean 
marine basin, and making Turrijaumelia a subjective synonym of Steironepion. 



In "Poeyana", published under the auspices of 
the Institute of Zoology, Cuban Academy of 
Sciences, Havana, Cuba, Dr. Hortensia Sarasiia 
described a new turrid gastropod, erecting the 
new genus and species Turrijaumelia jaumei. 
Although the type specimen of Pleurotoma 
maculata Adams, 1850, figured by Clench and 
Turner, is a worn specimen, there seems little 
doubt that T. jaumei should be synonomized 
with that taxon. None of the Cuban or Baha- 
maian specimens were live-taken. 

Perusal of George Radwin's comprehensive 
treatment of the family Columbellidae in the 
western Atlantic, would suggest adding this 
species to the genus Steironepion which now 
contains the Caribbean species S. minor (C. B. 
Adams, 1845) and S. moniliferum Sowerby, 
1844). Placement of this columbellid in the Tur- 
ridae by Adams and Sarasiia may have resulted 
in their considering the rather swollen anal 
sinus as a turrid notch. 

Since C. B. Adams' description of this species 
is very brief, it is deemed desirable to translate 
and reproduce below Dr. Sarasiia's detailed 
description of this very attractive little shell. 



Turrijaumelia, new genus 

Description: Shells small, slender, not fragile 
but delicate. Large nuclear whorls, smooth and 
bulbous, the post nuclear whorls are character- 
ized by angular perimeters and well defined 
sutures. Sculpture reticulated, formed by thin 
axial ribs, crossed by smooth spiral cords, form- 
ing sharp rib projections on the lower half of the 
whorls. The spaces between the reticulated 
sculpture reveal numerous microscopic axial 
threads. Aperture narrow, sigmoidal, with the 
anal channel somewhat enlarged. Outer lip with 
slight stromboid notch, showing interior liration 
and the anterior canal recurved backwards and 
to the right. 

Genotype - Turrijaumelia jaumei, new species 

Discussion: Among the many genera of the 
Turridae, we have not been able to find one fit- 
ting our lot; the bulbous and smooth nuclear 
whorls, the angular periphery of the post 
nuclear whorls, the smooth spiral cords, the rib 
projections and the peculiar microscopic axial 
threads in the reticulated spaces, give us what 



74 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



we believe to be sufficient characteristics to 
establish the new genus Turrijaumelia. 

Turrijaumelia jaumei, new species 
Description: Shell small, elongated and 
graceful, of delicate and vitrious appearance; 
nuclear whorls two, large bulbous and smooth, 
followed by 4-4.25 post-nuclear whorls, well 
defined suture and angular periphery. The last 
whorl narrows and forms the siphon canal com- 
pleting the graceful appearance of the species. 
Sculpture consisting of marked narrow ribs, 
more or less 12 on the last whorl, higher on the 
lower half of the whorls and more slender at the 
base of the shell, crossed by smooth spiral cords, 
well separated. At the top half of the whorls, 
which are strongly sloped, there are 3 or 4 spiral 
cords of the same width, separated by a space 
more or less the same width as the width of 
these cords. The spiral cords on the lower half of 
the whorls are wider and more separated from 
one another, the first extends from the middle 
line of each whorl, and these in turn form the 
sharp rib projections which point upwards; 
three of these spiral cords are observed on the 
last whorl. At the base of the last whorl are two 
spiral cords, the first of which may have slender 
projections, on the second these may appear in- 
stead as small nodules. On the siphon canal are 
two spiral cords of small nodules, followed by 
three narrow cordlets. 

In the translucent spaces of the reticulated 
area, which on the lower half of the whorls, are 
large and rectangular, are microscopic axial 
threads, straight and parallel, separated from 
one another by spaces more or less the same as 
their width; these axial threads reach the sides 
and surface of the ribs, and at the point appear 
slightly curved. On the siphon canal the spiral 
sculpture is crossed by microscopic axial lines. 
The outer lip of the aperture reveals four den- 
ticulations on the inside border formed by the 
termination of the lirations, the two upper ones 
being clearly visible. The general color of the 
shell is white, a few brown spots are observed on 
the upper part of the spiral cords where the 
whorls slope downward; the base of the last 
whorl may be yellowish, and a touch of brown 
may appear on the last rib. On the nuclear 
whorls, at the beginning of the suture, there is 
generally a brownish spot. 



The measurements given for the width of the 
shells, are without consideration to the 
sculptural projections. 

Width Width 

Length (greatest) (narrowest) 

Holotype 4 mm 1.75 mm 1.70 mm Marianao, Habana 
Paratype 4 mm 1.60 mm 1.50 mm Marianao, Habana 
Paratype 4.1 mm 1.50 mm 1.40 mm Marianao, Habana 

The type shells form part of a lot of 19 
specimens, dredged from sand at a depth of ap- 
proximately 20 metres, were taken offshore at 
Marianao, Habana, and collected by Sr. Primi- 
tivo Borro. Another three specimens were found 
by the author in sand from the same location. 
Type catalog No. 36 (holotype) and 37 and 38 
(paratypes.) 

Steironepion maculatum (C. B. Adams, 1850) 
(Figs. 1. 2) 

Synonomy - 

1850 Pleurotoma macuiata C. B. Adams. 1850, Contribu- 
tions to Conchology, No. 4, p. 62 (Jamaica); 1950 Clench 
and Turner, Occasional Papers on Mollusks, vol. 1, No. 
15, p. 305, pi. 29, fig. 3 (holotype) 

1887 Pleurotoma (DriUia) maculata Verkruzen. Paetel, 
Catalog der Conchylien-Sammlung von Fr Paetel. vol. 1. 
p. 56 (Jamaica), [listing only]. 

1975 Turrijaumelia jaumei Sarasua, Poeyana (Havana), No. 
140, pp. 12-15, (20 metres, off Marianao, Habana, Cuba). 

Records -BAHAMAS: West Beach, Staniel 
Cay, Exhumas, Dieter Cosman collector, 1966. 
CUBA: Varadero Beach, North coast of Cuba 
(drift), C. John Finlay collector, 1952; Marianao, 
Habana, Primitivo Borro and Hortensia 
Sarasua, from sand dredged in 20 metres. 
JAMAICA: C. B. Adams, 1850; Paetel, 1887. 

Genus Steironepion Pilsbry and Lowe, 1932 

Synonomy - 
1932 Steironepion Pilsbry and Lowe, Proc. Acad. Sat. See 

Philadelphia, vol. 84, p. 57 (type by original designation: 

Mangelia melanosticta Pilsbry and Lowe, 1932). 
1943 Psarostola Render, Proc U. S. Nat. Mus., vol. 93, No. 

3161, p. 198 (type by original designation: Columbella 

monilifera Sowerby, 1844). 
1975 Turrijaumelia Sarasua, Poeyana (Havana), No. 140, 

pp. 12-15, (type by monotypy: T. jaume) Sarasua. 1975) 

This interesting group of small columbellids 
with a reticulated or beaded sculpture and a 
strong anal notch has been placed in the turrids 
by many authors until Rehder (1943), Keen 
(1971) and Radwin (1977) showed its columbellid 
affinities both in shell and radular characters. 
Curiously, Sowerby (1844), Duclos (1848 and 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 75 




FIGS. 1, 2. Steironepion maeulatum (C. B. Adams, 1850). 
Beach drift, Varadero Beach, north coast of Cuba, 1952, 4.5 
mm, C. J. Finlay collector. 

Try on (1883) also placed Steironepion rnonili- 
ferum (Sowerby, 1844) in the Columbellidae. 



Radwin (1977) removed Steironepion from the 
genus Nassarina and considered it a full genus, 
a view in which I concur. 



Acknowledgments 

Thanks go to Dr. R. Tucker Abbott for his en- 
couragement in writing this paper and for his 
critical reading of the manuscript. I am also in- 
debted to Mrs. Virginia 0. Maes for reviewing a 
preliminary outline of the paper. To Mr. Paul 
Mikkelsen many thanks are due for the fine 
photographs of the Varadero Beach specimens. 



LITERATURE CITED 

Clench, W. J. and Turner. R. D., 1950. The Western Atlantic 
Marine Mollusks described by C. B. Adams. Occasional 
Papers on Mollusks, Vol. 1, June 26, 1950. 

Sarasua, H., 1975. New Genera, Subgenera and Species of 
Neogastropod Marine Mollusks, Poeyana. Academy of 
Sciences, Habana, Cuba. No. 140, pp. 12-15, January 17. 
1975. 

Radwin, G. E., 1977. The Family Columbellidae in the West- 
ern Atlantic, Part Ha. The Veliger, Vol. 20, No. 2, 
pp. 119-133. 



ACTIVITY PATTERNS AND HOMING IN TWO INTERTIDAL 
LIMPETS, JORDAN GULF OF AQABA 



Neil C. Hulings 

Marine Science Station 

P.O. Box 570 

Aqaba, Jordan 

ABSTRACT 
The foraging and homing behavior of Cellana radiata (Born) and Siphonaria 
laciniosa (Linne) occurring in the rocky intertidal zone has been determined. C. 
radiata, a prosobranch, forages when submerged during day and night, is a tem- 
porary homer and migrates up and down with changes in sea level. S. laciniosa, a 
pulmonale, forages when submerged but only after sunset and is a rigid homer. 
Homing behavior in relation to desiccation and density dispersion are discussed. 
Migration, intra- and interspecific competition are also discussed. 



Activity patterns, including foraging and 
homing of many prosobranch and pulmonale 
limpets, have been investigated for many years. 
The patterns, especially foraging or feeding ex- 



cursions, have been found to be quite variable as 
to when and under what conditions they occur. 
Homing has also been found to be variable and 
various reasons have been proposed for such 



76 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



behavior including reduction of desiccation, bet- 
ter utilization of resources, especially food and 
protection from predators (Underwood, 1979; 
Branch, 1981; Garrity and Levings, 1983 and in- 
cluded references). 

There are only two limpets found in the rocky 
intertidal zone along the coast of Jordan, the 
patellid Cellana radiata (Born, 1778) (alias C. 
rota (Gmelin, 1791)) and the pulmonate Sipho- 
naria laciniosa Linne, 1758 (alias S. kurra- 
cheensis Reeve, 1856). C. radiata is the larger of 
the two species, reaching lengths of up to 48 
mm, whereas S. laciniosa rarely exceeds 20 
mm. Both species occur in the midlittoral zone 
of Stephenson and Stephenson (1949) within 
which Safriel and Lipkin (1964) designated a 
higher chthamalid zone and a lower Tetraclita 
zone. C. radiata has a wide vertical distribution, 
ranging from above the chthamalid zone to 
below the Tetraclita zone and occurs on vertical 
to horizontal surfaces of boulders, pebbles and 
various types of slab substrata. S. laciniosa, in 
contrast, is mostly restricted to near the chtha- 
malid zone (within the range of C radiata) and 
occurs more commonly on horizontal, soft, cal- 
careous substrata rather than on hard sub- 
strata. Both limpets are grazers, feeding on 
microalgae. 

Prior to the present report, nothing was 
known of the foraging and homing behavior of 
Cellana radiata and Siphonaria laciniosa in the 
Red Sea. Voucher specimens of both species are 
on deposit in the U.S. National Museum of 
Natural History and in the reference collection 
of the Marine Science Station in Aqaba, Jordan. 

The Rocky Intertidal 

The rocky intertidal zone along the coast of 
Jordan is quite variable, ranging from granitic 
boulders to multicolored pebble beaches to low 
profile slab or platform beaches. The latter may 
be sandstone, gravel-pebble conglomerate, 
beach rock or fossil coral reef consisting of 
eroded coral heads in a cemented calcareous 
matrix. Wave action on slab beaches is usually 
minimal as they are protected by outer reef 
crests or occur on the leeward side of land pro- 
jections. 

The mixed tides have a spring range of about 1 
m and a neap range of around 50 cm (Fishelson, 
1973; Hulings, unpublished data). The diurnal 



inequality averages 4.2 cm for the high tides, 
and 4.7 cm for the lows (Hulings, unpublished 
data). Fluctuations in sea level of up to 1 m 
occur. From December through May, the sea 
level is the highest; from July through 
September-October it is the lowest (Fishelson, 
1973; Hulings, unpublished data). From late 
September through November there is a 
gradual rise in sea level, and from late May 
through June there is a gradual lowering. 

There is no river discharge into the Gulf of 
Aqaba and this in combination with low rainfall 
(23 mm/yr, Morcos, 1970), high evaporation (up 
to 4 m/yr, Anati, 1976), prevailing N-NNE, hot 
and dry winds (Hulings, 1979) results in a con- 
stant salinity of 40.5 to 41.5 ppt (Paldor and 
Anati, 1979). The mean air temperature has a 
wide range, from about 16°C in January to 32°C 
in August (Jordan Meterological Department), 
while water temperature has a much narrower 
range, from 20°C in February to 27°C, in 
August- September (Morcos, 1970). 



Methods and Materials 

Most of the data on the activity and homing of 
Cellana radiata were obtained from specimens 
living on a low profile calcareous fossil reef plat- 
form in the midlittoral zone above the Tetraclita 
zone; additional data on C. radiata were ob- 
tained on specimens occurring on large and rela- 
tively smooth granitic pebbles. The shells and 
the home area were color-coded, using either 
enamel paint or fingernail polish. Three color- 
coded groups of 15 specimens, each occurring 
on the calcareous substratum and averaging 
30.1 mm in length, were observed continuously 
from 6 October through 7 November 1983 and 
periodically through 15 February 1984. The 19 
color-coded C. radiata occurring on the granitic 
pebbles averaged 24.0 mm in length and were 
observed from 6 October through 7 November 
1983. 

I ii order to obtain informal ion on I lie overall 
movement of Cellana radiata, 55 individuals 
(average length of 25.4 mm) within a 1 m 2 area 
were painted and then observed from 11 
September through 7 November 1983 on a daily 
basis and periodically through mid-June 1984. A 
1 m 2 metal frame divided into 10 x 10 cm quad- 
rates was put in the same place during low tide, 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 77 



the time of observation, and removed after each 
observation. 

For Siphonaria laciniosa, a total of 90 indi- 
viduals, averaging 15.2 mm in length, were 
color-coded and observed from 10 September 
through 9 November 1983 and periodically 
through mid-July 1984. The 90 individuals con- 
sisted of four separate populations, two of which 
consisted of 12 and 34 individuals occurring on 
eroded coral reef heads having a very irregular 
surface; 25 specimens occurred on a relatively 
smooth, cemented, calcareous matrix, and a 
fourth population of 16 individuals occurred on 
beachrock of cemented granule-sized grains. 
Concurrent observations were conducted on six 
specimens averaging 13.2 mm in length kept 
submerged in an aquarium with running sea 
water. 

Observations on Cellana radiata and Sipho- 
naria laciniosa were made during day and 
night, spring and neap tides, flooding and ebb- 
ing tides and during complete submergence and 
emergence as well as combinations of the above. 

Results 

Cellana radiata became active soon after sub- 
mergence and returned from foraging during 
the period from maximum flood tide to just 
before or after emergence. Movement during 
foraging was not continuous and the distance of 
the excursions varied from 3 to 35 cm. The 
direction of movement varied from predomi- 
nately unidirectional to up to 45° from the main 
direction. Limited data indicates that the return 
is along the outgoing path. There were individ- 
uals that did not forage during consecutive 
cycles of submergence. During emergence, C. 
radiata remained inactive. The periods of forag- 
ing activity and inactivity occurred equally 
during day and night. 

The homing behavior of Cellana radiata was 
extremely variable. Among three groups each of 
15 color-coded specimens living on relatively flat 
calcareous substrata 38% were initially non- 
homers. For the homers, the percent of the in- 
dividuals returning to the original home 
decreased to 4% over a period of 33 days. Simi- 
lar decreases in homing were noted among 
other marked specimens on the large and 
smooth granitic pebbles. The decrease in the 
percent of homers was not, however, constant. 



Fluctuations in the percent occurred because of 
the return of some individuals to the original 
home after one or more days of absence. Many 
of those that left the original home subsequently 
established one or more new homes. In cases 
where the home was occupied by another in- 
dividual, the homer returned to as close as possi- 
ble to the home but did not dislodge the new 
occupant. 

The average number of days that Cellana 
radiata occupied the original home was 11 and 
ranged from 1 to 22. Those specimens occupying 
a new home did so for an average of 3 days 
(range, 2 to 7). 

The homing scar of Cellana radiata on a cal- 
careous substratum was either entirely greenish 
in color or greenish with the periphery tan to 
white. The latter color pattern appeared to be 
characteristic of those individuals homing for 
extended periods. The color patterns disap- 
peared, however, a few days after the home was 
vacated. No depressions, excavations or other 
physical markings in the scars were seen. Scars 
were absent on the hard granitic pebbles. On the 
soft calcareous substratum scars from C. 
radiata were as small as 11.0 mm in length. 

The observations of the 55 marked Cellana 
radiata within the 1 m 2 area revealed that over 
a period of 55 days the number decreased from 
55 to 6. The number leaving the area was offset, 
however, by immigrants entering the same 
area. The exodus was gradual as was the im- 
migration into the area. The result was that the 
density in the m 2 area remained relatively con- 
stant, averaging 58 individuals/m 2 over a period 
of 55 days. 

The direction of movement of 55% of the 
marked Cellana radiata from the area was 
toward the high water mark or vertical while 
36% were to either side of the area and approx- 
imately parallel to the shoreline. The remaining 
8% moved seaward or vertically downward. A 
similar pattern of upward and/or lateral move- 
ment was noted among non-homing individuals 
marked for homing observations. Homing con- 
tinued among some individuals while migration 
occurred in others. There was no obvious direc- 
tional movement of the immigrants into the m 2 
area although there appeared to be net move- 
ment toward the high water mark. During May 
and June 1984, a general pattern of seaward 



78 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



migration was noted among remnants of the 
originally marked populations. 

The foraging activity of Siphonaria laciniosa 
was restricted when they were submerged and 
was begun only after sunset. Activity occurred 
either during flooding or ebbing tides but only as 
long as the individuals were submerged and 
usually within a minimum of 30 minutes after 
sunset, but more commonly 45 to 60 minutes 
after sunset. Excursions of up to 20 cm and 
averaging 54 minutes in length (range, 25 to 100 
minutes) occurred. Movement was not con- 
tinuous during the foraging excursions. The 
return to the home locality was usually along the 
outgoing path. 

The number of Siphonaria laciniosa within a 
particular population foraging at a particular 
time was extremely variable. Rarely did all the 
individuals of a given population forage during 
one period of suitable conditions. In some cases, 
there was no foraging among any of the indi- 
viduals of a given population on a particular oc- 
casion. There appeared, however, to be almost 
total foraging activity among all individuals 
within a population on successive periods of 
suitable conditions. 

Without exception, all Siphonaria laciniosa 
homed following the foraging excursions, in- 
cluding specimens continually submerged in an 
aquarium. Furthermore, the homing was found 
to be rigid in that it was continuous over the 
period from 10 September through 9 November 
1983. An exception was in three specimens 
which moved to a new home but subsequently 
remained at the new home. Observations 
through mid- July 1984 revealed all of the 
originally observed S. laciniosa occupying the 
same homes. 

The scar of Siphonaria laciniosa occurring on 
calcareous substrata was white in the center and 
green on the periphery. The coloration disap- 
peared, however, within a few days after the 
home was no longer occupied. The scar was 
usually a depression, part of which was com- 
monly surrounded by a ridge. The surface of the 
depression tended to be smoother than the sur- 
rounding substratum. The depressions were 
generally more common among large than small 
specimens. Among both large and small individ- 
uals, the edge of the shell conformed to the con- 
figuration of the substratum. 



Scars with the coloration pattern and depres- 
sion were absent among Siphonaria laciniosa 
occurring on hard, non-calcareous substrata 
such as granular beach-rock and pebbles. 
Among these homing individuals, the edge of 
the shell conformed to the surface configuration 
of the substratum regardless of the irregularity. 



Discussion 

The patterns of foraging activity and homing 
in the two rocky intertidal limpets along the 
coast of Jordan are very different. The patellid, 
Cellana radiata, is a temporary or non-rigid 
homer, as well as being migratory. In addition, 
it is active both day and night but forages only 
when submerged. In contrast, the pulmonate, 
Siphonaria laciniosa, is a rigid homer and does 
not migrate; foraging occurs only after sunset 
and when it is submerged. The patterns of activ- 
ity in both species occurred irrespective of tidal 
or lunar cycles. 

Rao and Ganapati (1971) reported that Cel- 
lana radiata from the tropical west coast of 
India exhibited homing behavior but with no in- 
dication of whether homing was temporary or 
permanent. They further reported that homing 
occurred only on rough substrata and not on 
smooth surfaces and that movement occurred 
only during submergence. Cellana radiata from 
the Jordan Gulf of Aqaba has been found to 
home temporarily on smooth, as well as rough 
surfaces. 

Cellana radiata from the Jordan Gulf of 
Aqaba exhibits the same temporary homing be- 
havior as reported by Branch (1975) for Patella 
(jranularis Limit' and by Macka\ and Under- 
wood (1977) for C. tramoserica (Sowerby). In 
addition, C. radiata generally fits the category 
of migratory species established by Branch 
(1981) for Patella spp. The homing behavior 
found in Siphonaria laciniosa is consistent with 
that of other siphonariids (Branch, 1981 and in- 
cluded references). The conditions and timing of 
foraging excursions in S. laciniosa are, 
however, different from that of other species 
summarized by Branch (1981) in occurring only 
when submerged and after sunset. 

Homing behavior among intertidal limpets is 
often considered as a response to minimizing 
desiccation. In the case of the homing behavior 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 79 



of Cellana radiata reported here, homing is 
considered insignificant in relation to desicca- 
tion. C. radiata is a temporary homer with a 
temporary scar and the edge of the shell usually 
does not fit closely to the substratum. In addi- 
tion, during emersion the shell is raised from the 
substratum rather than being clamped down, 
the mantle cavity contains copius fluid and there 
is no formation of a mucus sheet reported by 
Wolcott (1973). 

In the case of Siphonaria laciniosa, however, 
homing is considered significant in reducing 
desiccation. S. laciniosa, a rigid homer, returns 
to a permanent scar following foraging and 
there is a good fit of the edge of the shell to the 
substratum on soft (calcareous) and hard bot- 
toms. And during emersion, the shell is clamped 
to the substratum. 

The significance of homing in Cellana radiata 
may be related to what Mackay and Underwood 
(1977, p. 215) proposed for Cellana tramoserica 
which, as noted above, are similar in homing 
behavior. They hypothesized "homing behavior 
as an adaptation which regulates local density 
and dispersion to maximize utilization of food 
resources and, thus, to reduce intraspecific com- 
petition for food at high densities of limpets". 
Support for this hypothesis in C. radiata may be 
found in the results of the movement through a 
1 m 2 area over a period of 58 days. During that 
period there was gradual emigration of marked 
individuals from the area and gradual immigra- 
tion of new individuals into the area. The result 
of the emigration and immigration was that the 
density of individuals within the unit area re- 
mained relatively constant. 

The pattern of shoreward or upward migra- 
tion in Cellana radiata during late September 
through November is considered as a response 
to the increase in sea level, increased food sup- 
ply and reduced physical extremes. As noted 
above, late September through November is the 
period of transition from lowest sea level (July 
through mid-September) to highest sea level 
(December through May). With an increase in 
sea level, more area is submerged for a longer 
period of time thus favoring increased food sup- 
ply in the form of microalgae and a reduction in 
physical extremes. Thus, C. radiata, microalgal 
grazer and feeding only when submerged, takes 
advantage of the increased area of suitable con- 



ditions. The observed seaward or downward 
movement of C. radiata that occurred begin- 
ning in late May more or less coincided with a 
gradual lowering of the sea level. It is con- 
sidered as an attempt to avoid the greater ex- 
tremes in the physical environment and reduced 
food supply. A similar pattern of migration 
described above with, however, varying 
degrees, has been found among some proso- 
branch gastropods occurring in the rocky inter- 
tidal on the Jordanian coast (Hulings, unpub- 
lished data). 

Siphonaria laciniosa responds in different 
ways to the change in sea level. As a non- 
migrant, it remains in the same position regard- 
less of the change in sea level. During the period 
of high sea level, it is submerged more often and 
for a longer period of time. It is during this 
period that S. laciniosa deposits egg ribbons 
during the night on exposed surfaces and that 
the hatching of veligers occurs (Hulings, in 
preparation). During the period of lowered sea 
level, air temperatures are higher and periods of 
emergence are longer. Thus, homing behavior 
as a response to lowered sea level minimizes 
desiccation. 

Although an investigation of predation was 
not conducted, observations indicate a high mor- 
tality rate in Cellana radiata compared to 
Siphonaria laciniosa based on the finding of 
empty shells on the beach. A mortality rate of 
22% was found among marked S. laciniosa over 
a 10-month period (no comparable data for C. 
radiata). What portion of the mortality is attri- 
butable to predation is not known. Most of the 
empty shells of both limpets did not exhibit 
physical damage. 

The spatial distribution of Siphonaria 
laciniosa tends to be more clumped than widely 
dispersed. Pairs and groups of individuals occur- 
ring in close proximity to each other are fairly 
common. Recruitment into areas of established 
populations was noted, and in some cases, the 
recruits were close to older individuals. Thus, 
there appears to be no aggressive behavior nor 
territorial defense by S. laciniosa. A similar 
situation probably prevails in Cellana. radiata 
based on homers not dislodging new occupants. 

Limited data and observations show that 
where Cellana radiata is abundant, Siphonaria 
laciniosa is very low in abundance or absent and 



80 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



vice versa. This pattern of density distribution 
often exists at the same vertical level within the 
midlittoral zone. Whether this indicates inter- 
specific competition between the two limpets re- 
mains to be elucidated. In addition, the area 
occupied by Cellana radiata is usually devoid of 
microalgal grazers other than Siphonaria 
laciniosa and vice versa. It would appear, there- 
fore, that competition for food is minimal. 

Acknowledgments 

The author wishes to thank Dr. Joseph Rose- 
water, U.S. National Museum of Natural 
History, for verification of the identification of 
the species. Thanks are also expressed to Dr. 
Jean de Vaugelas, University of Nice, for 
critical reading of the manuscript. Financial 
support by the Office of the Dean Resource, 
Yarmouk University is greatly acknowledged. 

LITERATURE CITED 

Anati, D. A. 1976. Balances and transports in the Red Sea 
and the Gulf of Elat (Aqaba). Israel J. Earth Sci. 25: 
104-110. 

Branch, G. M. 1975. Mechanisms reducing intraspecific com- 
petition in Patella spp.: migration, differentiation and 
territorial behavior. J. Anim. Ecol. 44:575-600. 



1981. The biology of limpets: physical factors. 

energy flow, and ecological interactions. Oceanogr. Mar. 
Biol. Ann. Rev. 19:235-380. 

Fishelson, L. 1973. Ecological and biological phenomena 
influencing coral-species composition on the reef tables at 
Eilat (Gulf of Aqaba, Red Sea). Mar. Biol. 19:183-196. 

Garrity, S. D. and S. C. Leving. 1983. Homing to scars as a 
defense against predators in the pulmonate limpet Sipho- 
naria gigas (Gastropoda). Mar. Biol. 72:319-324. 

Hulings, N. C. 1979. Currents in the Jordan Gulf of Aqaba. 
Dirasat 6:21-33. 

Mackay, D. A. and A. J. Underwood. 1977. Experimental 
studies on homing in the intertidal patellid limpet 
Cellana tramoserica (Sowerby). Oecologia 30:215-237. 

Morcos, S. A. 1970. Physical and chemical oceanography of 
the Red Sea. Oceanogr. Mar. Biol. Ann. Rev. 8:73-202. 

Paldor, N. and D. A. Anati. 1979. Seasonal variations of 
temperature and salinity in the Gulf of Elat (Aqaba). 
Deep-Sea Res. 26:661-672. 

Rao, M. B. and P. N. Ganapati. 1971. Ecological studies on a 
tropical limpet, Cellana radiata. Mar. Biol. 9:109-114. 

Safriel, U. and Y. Lipkin. 1964. On the intertidal zonation 
of the rocky shores at Eilat (Red Sea, Israel). Israel J. 
Zool. 13:187-190. 

Stephenson, T. A. and A. Stephenson. 1949. The universal 
features of zonation between tidemarks on rocky coasts. 
J. Eeol. 37:289-305. 

Underwood, A. J. 1979. The ecology of intertidal gastro- 
pods. A dv. Mar. Biol. 16:111-210. 

Wolcott, T. G. 1973. Physiological ecology and intertidal 
zonation in limpets (Acmaea): a critical look at "limiting 
factors". Biol. Bull. 145:389-422. 



MEETINGS 

Western Society of Malacologists 

August 18-21, 1985 

The annual meeting of the Western Society of 
Malacologists will be held on the campus of the 
University of California, Santa Barbara. The 
main emphasis will be on the molluscan fauna of 
the Eastern Pacific with sessions including land 
snails, paleontology, etc. There will also be a 
symposium on Hawaiian mollusks chaired by 
Mrs. Beatrice Burch. 

Anyone interested in pre-registration or call 
for papers please contact William D. Pitt, presi- 
dent, WSM, 2444 38th Ave., Sacramento, CA 
95822. Telephone (916) 428-3899, home even- 
ings. 



DEATHS 
Joseph Rosewater, 1928 - 1985 
Joseph Rosewater, Curator of Mollusks at the 
U.S. National Museum since 1960, a past-Presi- 
dent of the American Malacological Union, and 
a long-time contributor to The Nautilus, died 
after a relatively short illness on March 22, 
1985, in Washington, DC, at the age of 56. He is 
survived by a son, two daughters and his widow, 
Mary Carlson Rosewater, 818 Woodley Drive, 
Rockville, MD 20850. An obituary and list of his 
publications will appear in the joint Clench- 
Rosewater memorial issues of the 100th Anni- 
versary volume of The Nautilus in 1986. We are 
informed that a fellowship fund for visiting 
mollusk students will be set up at the Smith- 
sonian Institution in memory of Dr. Rosewater. 



Vol. 99 (2-3) 



April 29, 1985 



THE NAUTILUS 81 



THE LAND SNAIL FAMILY HYDROCENIDAE IN VANUATU 

(NEW HEBRIDES ISLANDS), AND COMMENTS ON 

OTHER PACIFIC ISLAND SPECIES 



Fred G. Thompson 

Florida State Museum 
University of Florida 
Gainesville, FL 32611 



and 



Emilye L. Huck 

P.O. Box 4413 
Winter Park, FL 32793 



ABSTRACT 
Georissa obsoleta new species (Gastropoda, Prosobranchia, Archeogastropoda, 
Hydrocenidae) is described from- Efate Island, Republic of Vanuatu. It is charac- 
terized by its minute size, obsolete sculpture, channelled suture, and conical form. 
It is the first record of Hydrocenidae from Vanuatu. Relationships with other 
Pacific species are not clear. The Hawaiian Georissa neili Pilsbry, 1928 is 
synonymizedwithG. cookei Pilsbry, 1928. G. kauaiensis Pilsbry, 1928 (Hawaiian 
Islands). Chondrella striata Pease, 1871 (Cook Islands), and Cyclostoma 
minutissima Sowerby, 1832 (Pitcaim Island) are based on juvenile specimens but 
appear to be Georissa. 

Key words: land snails, Hydrocenidae, Georissa obsoleta, Pacific Islands, 
Vanuatu, New Hebrides Islands, Efate Island. 



During June- August, 1984 the junior author 
had the opportunity to visit the Republic of 
Vanuatu, formerly called the New Hebrides 
Islands. Significant collections of land snails 
were made on Efate, Erromango, and Tanna. 
The collections are particularly interesting 
because of the large number of minute species 
that were recovered from leaf-litter samples 
gathered at many stations. A species of par- 
ticular interest to us is described below. It is the 
first record of the family Hydrocenidae from 
Vanuatu. 

Hydrocenid land snails are widely deployed on 
Pacific islands, Japan, New Zealand, Australia, 
the Indo-Australian archipellago, Southeast 
Asia, Madagascar, Africa, and Mediterranean 
Europe. They are poorly known because of their 
minute size and cryptic behavior, although they 
may be locally abundant (Thompson and Dance, 
1983). Most species are confined to limestone 
substrates and encrust their shells with lime or 
mud. Live specimens appear more like minute 
blobs of dirt than like coiled shells. Thus, it is not 
surprising that this family was not reported in 
the two principal papers on the New Hebrides 
fauna (Solem, 1959, 1962). Because the new 
species has very poorly developed shell 
sculpture we name it: 



Georissa obsoleta 

Thompson and Huck, new species 
Shell (Figs. 1-7): Minute, adults about 1.7-1.9 
mm long, about 0.72-0.78 times as wide as high. 
Color varying from yellow-gray to fulvous in 
fresh shells. Conical with a wide rounded apex; 
consisting of 3.3-3.7 whorls. Apex rounded, with 
a large cap-shaped protoconch consisting of 1.3 
whorls (Fig. 6). Protoconch sculptured with a 
dense mesh of minute pits. Suture between 
whorls of teleoconch very deeply impressed, 
forming a channel around middle of shell (Fig. 
5). Sculpture of teleoconch consisting of very 
weakly developed spiral threads that form an 
obsolete cancellate pattern where they cross 
growth striations and threads (Fig. 2). Growth 
threads tend to be enlarged above shoulder of 
whorl and usually form weak denticles along 
second and third whorls (Fig. 5). Aperture ovate 
in shape, about as wide as or slightly wider than 
high; about 0.39-0.48 times length of shell. 
Parietal wall nearly straight, lying at an angle 
of 30-32° to axis of shell (30° in holotype); plane 
of aperture at 20-25° to shell axis (Fig. 3). Um- 
bilical area with a wide shield that is indented 
along outer edge (Fig. 7). Parietal septum ex- 
tending into shell for % whorl, where upon the 
earlier septum has been readsorbed (Fig. 4). 



82 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 




' 



© 




L-9 Georissa obsoleta Thompson and Huck, new species. 1. UF 50628a (x31). 2, UF 50629a(x31). 3. UF 50629a 
i F 50627 (x31). 5, UF 50628b (xl64). 6, UF 50628b ( x 205). 7, UF 50628a(x62). 8. inner surface of operculum 
i 9, oblique view of operculum at 70° from base (x82). 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 83 



Measurements for the holotype and five para- 
types (UF 50633) selected to show variation 
follow: 



length width apert. h apert. 



whorls 



1.64 
1.89 
1.80 
1.71 
1.61 



1.24 
1.40 
1.40 

1.27 
1.24 



0.74 
0.76 
0.84 
0.74 
0.74 



0.74 
0.87 
0.84 
0.74 
0.74 



3.6 
3.7 
3.6 
3.5 
3.1 



holotype 
paratype 
paratype 
paratype 
paratype 

Operculum (Figs. 8, 9): Calcareous, concentric 
with a large subcentral nucleus. Inner surface 
with a long slender peg along columellar 
margin. Peg lying at a relatively low angle to 
plane of operculum; dorso-ventrally flattened; 
base of peg extending out to columellar edge of 
operculum. Innter surface of operculum flat, 
with a narrow raised callus around edge (Fig. 8), 
but not to the extent that occurs in Chondrella 
parva (Pease, 1864). 

Type locality: Vanuatu, Efate Island, above 
Mele village along trail to the cascades, 75 m 
altitude. Holotype: UF 50631; collected 23 June 
1984 by Emilye L. Huck. Paratypes: UF 50632 
(57), UF 50633 (13 measured specimens), UF 
50634 (11), UF 50627 (1 gold plated), UF 50628 
(2 gold plated), UF 20629 (2 gold plated), 
Bernice P. Bishop Museum 207565 (6), Austra- 
lian Museum C144145 (5), Rijksmuseum van 
Natuurlijke Historie 55724 (5); same locality as 
holotype. 

The type series was collected from leaf-litter 
samples gathered at the base of a limestone 
knoll at the edge of a banana grove in a dense 
rain forest, along the cascades of a small river 
near Mele village. Most of the specimens are 
slightly weathered. A few specimens are in 
fresh condition and retain the natural color. The 
holotype is a slightly immature specimen 
selected because it is the freshest specimen in 
the lot, it shows details of sculpture and color 
and the operculum is retained within the aper- 
ture. The paratypes illustrated in Figs. 1, 2 (UF 
50628a) are nearly identical to the holotype but 
are very slightly larger. The figured operculum 
was recovered from a paratype (UF 50632). 



features distinguish the species from all other 
known Pacific Georissa. Five other species are 
described as being smaller, but their original 
descriptions appear to be based on juveniles and 
better material has not been reported. 

It is difficult to determine specific relation- 
ships because very little is known about the 
Pacific Hydrocenidae. Six species have been 
described from the northern and eastern 
Pacific. Three are recorded from Kauai, 
Hawaiian Islands, Georissa cookei Pilsbry, 1928, 
G. neili Pilsbry, 1928, and G. kauaiensis Pilsbry, 
1928. The three were recovered from moss 
samples collected from fallen logs on a ridge be- 
tween Hanalei and Wailua. The type specimens 
of all three are juveniles, and each is known 
from only one or two specimens. On the basis of 
variation that we have seen in other species (see 
Thompson and Dance, 1983) we suspect that G. 
cookei and G. neili are the same species, and we 
have little faith in the distinction of G. kauaien- 
sis. Regardless of their specific status, their 
juvenile shells do not permit comparisons with 
other species because definitive characteristics 
of size, shape, sculpture and whorl development 
cannot be determined. 

One species is known from the Cook Islands, 
Chondrella striata Pease, 1871, and one is 
described from Pitcairn Island, Cyclostoma 
minutissima Sowerby, 1832. Both appear to be 
typical Georissa and both are based on juvenile 
shells. Thus it is not possible to discuss their 
characteristics for the purpose of specific com- 
parisons, other than to say that they are sculp- 
tured more heavily than is G. obsoleta. 

Another species is recorded from the Society 
Islands, Cyclostoma parva Pease, 1864. It is 
much larger and smoother than G. obsoleta, and 
is placed in a separate genus, Chondrella, 
because of a heavy callused ridge around the in- 
side margin of the operculum. 

Other species are known from New Zealand, 
Australia, and islands to the north, but close 
relationships between G. obsoleta and these are 
not apparent. 



Discussion 

Georissa obsoleta is characterized by its 
minute size, its moderately wide, conical form, 
its channelled suture, and its sculpture. These 



Acknowledgments 

The junior author traveled to the Republic of 
Vanuatu (New Hebrides Islands) assisted by a 
grant provided by The Explorers Club Educa- 



84 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



tion and Youth Activities Fund and the Haver- 
lee Exploration Fund of the Central Florida 
Chapter of The Explorers Club. We wish to ex- 
press our gratitude to the society for this aid, 
and to Dr. R. Tucker Abbott for his encourage- 
ment. She was accompanied in the field by her 
mother, Robin B. Huck. Harvey A. Miller 
(University of Central Florida) led the expedi- 
tion while pursuing studies on Pacific bryo- 
phytes under the sponsorship of the National 
Science Foundation (Grant BSR-8215056). The 
SEM micrographs comprising the illustrations 
in this paper were prepared by Kurt Auffenberg 
(Florida State Museum) from the HITACHI 
S415A Scanning Electron Microscope in the 
Department of Zoology, University of Florida. 
George M. Davis (Academy of Natural Sciences, 
Philadelphia) loaned us specimens of Cyclostoma 
parva Pease for comparison. A discussion of its 
specific and generic status will be presented 
elsewhere by the senior author. We wish to ex- 



press our gratitude to all people who have 
assisted us in this study. 

LITERATURE CITED 

Pease, W. H. 1864. Descriptions of new species of land 

shells from the islands of the Central Pacific. Proe. Zool. 

Soc. Lond. for 1864: 668-678. 
1871. Catalogue of the land shells inhabiting 

Polynesia, with remarks on their synonymy, distribution 

and variation, and descriptions of new genera and species. 

Proc. Zool. Soc. Lond, for 1871: 449-477. 
Pilsbry, H. A. 1928. Georissa, a land snail genus new to the 

Hawaiian Islands. Bull. Bernice P. Bishop Mus. 47:3-4. 
Solem, A. 1959. Systematica of the land and freshwater 

Mollusca of the New Hebrides. Fieldiana (Zool.) 43: 

1-238; pis. 1-34. 
1959. Notes on. and descriptions of New 

Hebridean land snails. Bull. British Mus. (Nut Hist.) 

9:213-247; pis. 1-2. 
Thompson, F. G. and S. P. Dance. 1983. Non-marine mol- 

lusks of Borneo. II Pulmonata: Pupilliade, Clausiliidae. 

Ill Prosobranchia: Hydrocenidae, Helicinidae. Bull. Fla. 

Stat. Mus. (Biol. Sci.) 29(3): 101-130; Figs. 1-75. 



COMMENTS ON THE DISTRIBUTION OF FRESHWATER MUSSELS 
(UNIONACEA) OF THE POTOMAC RIVER HEADWATERS 

IN WEST VIRGINIA 

Ralph W. Taylor 

Department of Biological Sciences 

Marshall University 

Huntington, WV 25701 

ABSTRACT 
This report presents data collected in 1981 and 1984 on the mussels of the upper 
Potomac River located within the eastern panhandle of West Virginia. My data 
indicate that North Branch is devoid of mussels apparently as a result of extensive 
strip mining; South Branch has a small but healthy mussel population. The 
Cacapon River and Patterson Creek, tributaries to the Potomac, also have viable 
populations. Eight species of mussels were found in the Potomac headwaters. 
Elliptio complanata, E. fisheriana and Lampsilis ventricosa were fairly common 
and Alasmidonta varicosa, A. undulata, Anodonta cataracta, Strophitus undu- 
latus, and Lasmigona subviridis were uncommon throughout the system. Cor- 
bicula fluminea was found throughout the drainage with the exception of North 
r.nnich. 



The freshwater mussel fauna of the Potomac 
River headwaters is virtually unknown. Ort- 
mann (1919) has done the only previous exten- 
sive collecting in the region, and that was com- 



pleted around the turn of the twentieth century. 
He probably took a train to Romney, West 
Virginia, and then to Harpers Ferry to collect in 
the Potomac River over a distance that could be 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 85 



covered in a day's ride by buggy. All of his 
records are in the immediate area of these two 
towns. Johnson (1970) reported that Carol Stein 
did limited collecting at Harpers Ferry in the 
early sixties. I can find no evidence of other 
work having been done in the upper Potomac 
River. 

The reasons for the paucity of work there in- 
clude: very poor roads (until recently) into the 
area; a very difficult terrain to maneuver; and 
limited access to the river at any point. 

Clarke (1981), Johnson (1970), and Ortmann 
(1919) all indicated a depauperate assemblage of 
mussels in this stream. My report does not 
dispel those findings. There are small popula- 
tions present but they are widely spread and oc- 
cur more often in the smaller tributaries than in 
the main trunk of the river. The only population 
of considerable size that I found was located at 
an area locally known as Pack Horse Ford, just 
downstream of Sheperdstown, West Virginia. 
All other areas reported herein represent small 
populations of no more than a couple of dozen 
specimens from any one site. 

The Potomac River originates in the Potomac 
highlands in the eastern panhandle of West 
Virginia. The mainstem Potomac River then 
continues along the Maryland/West Virginia 
border for Ca. 160 km to Harpers Ferry where it 
receives the Shenandoah River which has its 
headwaters in Virginia. I have not collected 
below Harpers Ferry. Two other major tribu- 
taries in West Virginia are the Cacapon River 
and Patterson Creek (Fig. 1). 

Ortmann (1919) collected in the South Branch 
Potomac River at Romney and Southbranch and 
reported the following species: Elliptio com- 
planata (Lightfoot, 1786), Lasmigona subviridis 
(Conrad, 1835), Anodonta cataracta Say, 1817, 
Strophitus undulatus (Say, 1817) and Alasmi- 
donta varicosa (Lamarck, 1819). He also 
reported E. complanata and A. varicosa from 
the Shenandoah River at Harpers Ferry. Clarke 
(1981) reported Alasmidonta undulata (Say, 
1817) from the South Branch and Shenandoah 
rivers and A. varicosa from Cherry Run and 
Lost River, a small tributary of the Cacapon 
River. Johnson (1970) reported two additional: 
Lampsilis ventricosa (Barnes, 1823) and Ellip- 
tio fisheriana (Lea, 1838) [ = lanceolata (Lea, 
1820)]. The Cacapon River and Back Creek are 




FIG. 1. Headwaters of the upper Potomac River. 

listed as the localities where these two mussels 
were collected. 

My collecting was done during the summers of 
1981 and 1984. Collecting involved wading the 
streams and collecting specimens that had been 
observed through the use of a glass-bottomed 
viewbox (waterscope). The entire drainage was 
covered to the extent that it was practical. Many 
areas are virtually inaccessible and could be 
reached only by raft or canoe. The sites reported 
herein are the only ones where mussels were 
found in any appreciable numbers. At all other 
localities visited only an occasional isolated in- 
dividual was seen and seemed not to represent a 
viable population. Voucher specimens have been 
placed with the Ohio State University Museum 
and the Marshall University Malacological Col- 
lections. 

Collecting Sites 

1. Potomac River at Pack Horse Ford, approx- 
imately 1 km E of Sheperdstown, Jefferson Co., 
WV, off County Road (CR) 17/1. 

2. South Branch at U. S. Route (US) 50 
Bridge, 1 km W of Romney, Hampshire Co., 
WV. 

3. South Branch at Arnold Farm, S of Romney 
on CR 8/2, 9 km N of Hardy Co. line Hampshire 
Co., WV. 



86 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



4. South Branch, off CR 6, N of Village of 
Cunningham, Hardy Co., WV. 

5. South Branch, bridge on US 220 at Peters- 
burg, Grant Co., WV. 

6. Cacapon River, off SR 9, 5 km N of Village 
of Largent, Morgan Co., WV. 

7. Cacapon River, along CR 15 at public fish- 
ing area, Hampshire Co., WV. 

8. Cacapon River, 1.5 km S of Village of 
Capon Bridge on CR 14, Hampshire Co., WV. 

9. Cacapon River at bridge on CR 9/12, 
Morgan Co., WV. 

10. North River of Cacapon River, along 
Delray Road ( = CR 11), Hampshire Co., WV. 

11. Patterson Creek, along CR 46 near Fort 
Ashby, Mineral Co., WV. 

12. Patterson Creek, at intersection of CR 
28/3 and CR 28/10, Mineral Co., WV. 

13. Shenandoah River, at Harpers Ferry, 
Jefferson Co., WV. 

Discussion 

There are areas in the headwaters of the 
Potomac River drainage where small popula- 
tions of naiads still persist. The North Branch of 
the Potomac River, however, has no detectable 
mussel population. All the collecting sites 
showed signs of mining damage. The substra- 
tum was covered with heavy deposits of ochre 
indicating the presence of mining effluent. Cor- 
bicula Jluminea (Miiller, 1774) which was found 



everywhere else in the drainage, was not found 
in this major tributary of the Potomac. The rest 
of the headwaters showed little evidence of 
disturbance by man. Presently, most of the area 
is fairly pristine with no industry or logging ac- 
tivities. Farming centers around the production 
of apples so there is little stream siltation. 



Species Accounts 

Elliptio complanata: This species was the 
most commonly found species in the study area 
and was found at nearly every collection site. 

Elliptio fisheriana: Johnson (1970) stated that 
this may simply represent a northern form of 
Elliptio lanceolata. E. fisheriana is, however, 
being recognized by the committee of the 
American Malacological Union which is current- 
ly preparing a list of generally accepted names 
for the naiads. While never found in abundance, 
it is widespread throughout the headwaters. 

Lampsilis ventricosa: This species is normally 
an interior basin species. It was inadvertently 
introduced into the Atlantic drainage about the 
turn of the century. It has become well estab- 
lished and is quite common throughout much of 
the drainage. It has apparently replaced the 
resident species Lampsilis cariosa (Say, 1817) 
in the upper Potomac River. The Ohio State 
University Museum of Zoology has several 
specimens of L. cariosa from the lower Potomac 



TABLE 1. Distribution of naiad mussels in the headwaters of the Potomac River system 
by species. 

















Site Number 












z 1 


2 


3 


4 


5 


6 


7 8 9 


10 


11 


12 


13 


Elliptio complanata 


X 






X 


X 


X 


XXX 


X 


X 


X 




Elliptio fisheriana 


X 










X 


X 






X 




Lampsilis ventricosa 


X 


X 


X 


X 




X 


X 






X 


X 


Alasmidonta varicosa 


X 




X 


X 




X 








X 




Alasmidonta undulata 








X 












X 




Anodonta cataract a 


X 








X 














Lasmigona subviridis 


X 




X 














X 




Strophitus undulatus 




















X 


X 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 87 



but none from this reach (Stansbery, 1984, pers. 
comm.). 

Ahisiiiiilniiii! varicosa: Apparently fairly com- 
mon throughout the headwaters. Widespread 
throughout the Atlantic coastal drainages. 

Alasmidonta undulata: This species is ap- 
parently quite rare here as only five specimens 
were found. Widespread throughout the Atlan- 
tic coastal drainages. 

Anodonta cataracta: This species does not ex- 
hibit a widespread distribution in the head- 
waters. It is typically found in larger, slower- 
flowing bodies of water. Only four specimens 
were found during this study. 

Lasmigona subviridis: This small species may 
be more abundant than my collections indicate. 
It is a typical Atlantic coastal species and enjoys 
a widespread distribution in most of eastern 
North America. It has crossed the mountain 
barrier on at least one occasion and can be found 



in the New River system (a tributary of the Ohio 
River) of southern West Virginia. One specimen 
was found at each of three different collecting 
stations during this study. 

Strophitus undulatus: This species is not com- 
mon. Ortmann (1919) reported it only from 
South Branch at Romney. I found a single live 
specimen in Patterson Creek and a badly- 
weathered half shell in the Shenandoah River. 

LITERATURE CITED 

Clarke, A. H. 1981. The Tribe Alasmidontini (Unionidae: 
Anodontinae), Part I: Pegias, Alasmidonta, and Arcidens. 
Smithsonian Contributions to Zoology. No. 326, 101 p. 

Johnson, R. I. 1970. The Systematies and Zoogeography of 
the Unionidae (Mollusca: Bivalvia) of the Southern Atlan- 
tic slope Region. Bulletin of the Museum of Comparative 
Zoology. No. 140(6):263-449. 

Ortmann. A. E. 1919. A monograph of the Naiads of Penn- 
sylvania. Part 3. Systematic account of the genera and 
species. Memoirs of the Carnegie Museum 8:1-384. 



A SECOND MELAMPID (PULMONATA: BASOMMATOPHORA) 
FROM THE EARLY MIOCENE OF VENEZUELA 

J. Gibson-Smith and W. Gibson-Smith 

Quinta Puerta del Sol, Calle Tucupido, San Roman, Las Mercedes, 
Caracas 1060, Venezuela 



ABSTRACT 
Pedipes cf. P. mirabilis (Muhlfeld, 1816) was reported by the present authors 
(1979, p. 22) from the early Miocene (Burdigalian) Cantaure Formation, 
Paraguand Peninsula, Venezuela, being the first reported fossil occurrence of the 
genus. It is described now as the new species Pedipes mirandus and is considered 
to be the ancestor of the Recent cognate species P. angulatus C. B. Adams, 1852, 
from the Eastern Pacific and P. mirabilis from the Western Atlantic. 



The presence in the early Miocene (Burdi- 
galian) Cantaure Formation, Paraguana Penin- 
sula, Venezuela, of two members of the family 
Melampidae was reported by Gibson-Smith & 
Gibson-Smith (1979, p. 22). One of these, Tralia 
cf. T. ovula (Bruguiere, 1789), was later de- 
scribed by these authors (1982, p. 119) as the 
new species T. venezuelana, which lives along 
the north coast of Venezuela, occurring also in 
the late Pliocene Mare Formation, Cabo Blanco, 
Venezuela. This was only the second fossil 



record of the genus Tralia the other being T. 
vetula Woodring, 1928, from the Pliocene 
Bowden Formation, Jamaica. The second Can- 
taure form, Pedipes cf. P. mirabilis (Muhlfeld, 
1816), the first fossil record of the genus, is 
likewise now recognized as a new species, 
Pedipes mirayidus. It is considered to be the 
ancestor of the Recent cognate species P. 
angulatus C. B. Adams, 1852, from the Eastern 
Pacific and P. mirabilis from the Western 
Atlantic. The genus was reviewed by Clench 



88 THE NAUTILUS 



April 29, 1985 



Vol. 99(2-3) 



(1964, p. 119) and the only other Recent taxa of 
the region are P. liratus Binney, 1860, and P. 
unisulcatus Carpenter, 1866, both from the 
Eastern Pacific. 

The author of Pedipes was said by both Clench 
(loc. cit.) and Keen (1971, p. 848) to be Ferussac, 
1821, the former giving the type species as, 
"Pedipes afra Gmelin ( = P. pedipes Bruguiere), 
subsequent designation, Gray 1847." Abbott 
(1974, p. 333), on the other hand, gave the 
author as Bruguiere, 1792, with type species 
[Helix] afer Gmelin. According to Clench (loc. 
cit.) afer is a Pfeiffer, 1856, misspelling of afra. 
Zilch (1959, p. 68) was the first to name 
Bruguiere, 1792, as the author, the type species 
being Bulimus pedipes Bruguiere, 1789, by 
tautonymy. 



Subfamily Pedipedinae Crosse & Fischer, 1880 

Genus Pedipes Bruguiere, 1792 

Type species, by tautonymy, Bulimus pedipes 

Bruguiere, 1789. 

Pedipes mirandus 

Gibson-Smith & Gibson-Smith, n. sp. 

Figure 1 

Description: Shell minute. Protoconch hetero- 
strophic, submerged, last V2-whorl inclined, 
smooth. Teleoconch of 3Vi shouldered whorls, 
body whorl globose. Sculpture of flat, subequal 
spiral cords with narrower interspaces, sub- 
sutural cord prominent; 4 cords between it and 
the shoulder and about 23 below. Surface rough- 
ened by crowded, prosocline growth incremen- 
tals. Columella broad, inclined, with two in- 
clined folds, the lower the weaker. Parietal 
callus narrow, carrying a large fold lying closer 
to the anal notch than to the upper columellar 
fold. Outer lip thin, smooth within. 

Holotype: Natural History Museum Basel, No. 
H 17113. Height 2.25 mm, diameter 1.75 mm. 
Type locality: Known only from the lower shell- 
bed of the early Miocene Cantaure Formation, 
Paraguana Peninsula, Venezuela (GS-1-PGNA). 
Paratype: Paleontological Research Institution, 
PRI 30049. 

Remarks: The type material consists of 5 
small, complete specimens and, in the absence 
of even fragments of larger shells, are believed 
to be mature. While the absence of a labral den- 
ticle might suggest immaturity it is not a 




FIG. 1. Pedipes mirandus n. sp. Holotype, ventral view. 
Height 2.25 mm, diameter 1.75 mm. Early Miocene Can- 
taure Formation. Paraguana Peninsula, Venezuela. NHMB 
H 17113. SEM micrograph, x25. 



characteristic of all mature Pedipes, the equally 
small P. liratus also lacking a denticle (Keen, 
1971, fig. 2411). Comparison has been made 
with juvenile P. mirabilis of a similar size. The 
trivial name is from the same Latin root as 
mirabilis meaning "wonderful" or "singular". 

Comparisons: P. mirandus n. sp. is most 
closely related to P. angulatus and P. mirabilis, 
the sculpture and outline being similar. In its 
broad columella it more resembles P. angulatus 
and in the reduced extent of the parietal callus it 
more resembles P. mirabilis. It differs from 
both in being smaller with 1 or 2 fewer whorls, 
in having an inclined columella and inclined col- 
umellar folds, the lower smaller than the upper; 
in P. angulatus and P. mirabilis the columella is 
vertical, the folds are about equal in size and are 
horizontal. In both of these, moreover, the 
parietal folds lies midway between the upper 
columellar fold and the anal notch, whereas in P. 
mirandus the fold lies closer to the anal notch, 
dividing the gap into one-third and two-thirds, 
and it is more horizontally directed. 



LITERATURE CITED 
Abbott, R. T. 1974. American Seashells, 2nd edit., 663 pp., 

24 col. pis., text figs. Van Nostrand Reinhold Co., New 

York. 
Clench, W. .1. 1964. The genera Pedipex and Lacntadontti 



Vol. 99(2-3) 



April 29, 1985 



THE NAUTILUS 89 



in the Western Atlantic. Johnsonia 4(42):117-127, 

pis. 76-79. 
Gibson-Smith, J. and W. Gibson-Smith. 1979. The genus 

Arcinella (Mollusca: Bivalvia) in Venezuela and some 

associated faunas. Geos No. 24, pp. 11-32, 3 pis. 
1982. The subfamily Melampinae (Pulmonata: 

Basommatophora) in Venezuela, with descriptions of two 



new species. TheNautilus 96(3):1 16-120, 9 figs. 
Keen, A. M. 1971. Sea shells of tropical West America; 

marine mollusks from Baja California to Peru. 2nd. edit., 

Stanford Univ. Press, Calif., i-xiv + 1064 pp., ca. 4000 

text figs., 22 col. pis. 
Zilch, A. 1959. Gastropoda: Euthyneura. In Wenz's Hand- 

buch der Palaozoologie. Lief. 1, pp. 1-200. 



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CONTENTS 






THE 

NAUTILUS 

Volume 99, number 4 - October 31, 1985 

ISSN 0028-1344 



Twila Bratcher and Walter O. Cernohorsky 

Three New Deep-Water Indo-Paeifie and 

One Intertidal Brazilian Species of Terebra (Gastropoda) 91 

Dorothea S. Franzen 

Succinea vaginacontorta Lee (Gastropoda: Pulmonata: Succineidae) 94 

Harald A. Rehder 

A New Species of Coralliophila (Gastropoda: Coralliophilidae) from Southeastern Polynesia .... 97 

Raymond W. Neck 

Native Freshwater Mussels (Unionacea) as Fouling Agents in Electrical Generating Plants. . . 100 

William K. Emerson 

Teramackia dupreyae New Species, from off Western Australia (Gastropoda: Volutidae) 102 

Scott J. Herrmann and James R. Fajt 

Additional Colorado Records of Anodonta grandis grandis Say (Bivalvia: Unionidae) 107 

James E. Joy 

A 40-Week Study on Growth of the Asian Clam, Corbicula flnmirwa (Midler), 

in the Kanawha River, West Virgina 110 

Paul D. Hartfield and Richard G. Rummel 

Freshwater Mussels (Unionidae) of the Big Black River, Mississippi 116 

Courtney T. Hackney 

Variations of Shell Morphology in the Carolina Marsh Clam, Polymesoda caroliniana, 

from Southeastern United States (Corbiculidae) 120 

Randal L. Walker 

Growth and Optimum Seeding Time for the Hard Clam, Mercenaria mercenaria (L.), 

in Coastal Georgia 127 

Dorothea S. Franzen 

Anatomy of Oxyloma nuttalliana chasmodes Pilsbry 134 

Riidiger Bieler, Arthur S. Merrill and Kenneth J. Boss 

Pseudotorinia bullisi. New Species (Gastropoda: Architectonicidae) 

from Subtropical Western Atlantic 139 

Arthur E. Bogan 

A Comment on Strophitinae Gordon, 1981 (Unionidae, Bivalvia) 141 

Mark E. Gordon and John L. Harris 

Distribution of Lampsilis powelli (Lea) (Bivalvia: Unionacea) 142 



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Completely Revised and Expanded 

Between Pacific Tides 

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Edward F. Ricketts 

Jack Calvin & Joel W. Hedgpeth 

Revised by David W. Phillips 

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contain some 2,300 entries. Illustrated with 425 photographs and drawings. 
$29.50 



STANFORD UNIVERSITY PRESS 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 91 



THREE NEW DEEP-WATER INDO-PACIFIC AND ONE INTERTIDAL 
BRAZILIAN SPECIES OF TEREBRA (GASTROPODA) 



Twila Bratcher 

8121 Mulholland Terrace 
Hollywood, CA 90046 



and 



In 1982 on cruise 32 of R. V "Marion-Dufresne", 
under the direction of Dr. A. Guille, terebrid 
specimens were dredged from fifteen stations 
off Reunion Island in the Indian Ocean. On 
board were malacologists Dr. Philippe Bouchet, 
A. H. Waren, and B. Metivier. Two species new 
to science were dredged along with several un- 
common species. Among them were Hastula 
celidonota (Melville & Sykes, 1898), the only 
member of the genus with a dark dorsal splotch; 
Terebra virgo Schepman, 1913, a species with a 
white shell somewhat resembling T. funiculata 
Hinds, 1844; a range extension of Terebra mac- 
tanensis Bratcher and Cernohorsky, 1982 (the 
white color form). Those from Reunion Island 
differ from the typical form by having regular 
yellowish brown dots between the ribs on the 
subsutural band while those of the typical form 
are scattered irregularly. All the specimens 
mentioned above are in the collection of the 
Museum National d'Histoire Naturelle of Paris. 

A large new terebrid species, 97.6 x 14.4 mm, 
was dredged off the coast of Natal, South 
Africa, in 1983. The eastern continental shelf off 
South Africa, where this species was found, has 
barely been studied. The shelf was last dredged 
in 1901, other than incidental hauls made by Dr. 
R. N. Kilburn of the Natal Museum and Dr. 
Allan Connell. (Dr. R. N. Kilburn, pers. comm.) 
This no doubt is the explanation of why so large 
a species has remained undiscovered until the 
present time. 

The third new species is from the Western 
Atlantic and has been collected intertidally to 
30 m. It has been misidentified by dealers and 
others as T. doellojuradoi Carcelles, 1953. 

Family Terebridae Morch, 1852 
Terebra Bruguiere, 1789 
Terebra Bruguiere. Encycl. Meth. Hist. Nat. Vers l:xv. Type 
species by SD (Lamarck. 1799): Bucrnixm suhuhitiim 
Linnaeus, 1767. Recent; Indo-Pacific. 



Walter O. Cernohorsky 

Auckland Institute and Museum 
Auckland, New Zealand 

Terebra pseudopertusa 

Bratcher & Cernohorsky, sp. nov. 
(Figs. 4. 5) 

Diagnosis: A terebrid similar to Terebra 
pertusa (Born, 1778), but with the shell having 
mamillate protoconch and an extra row of 
squarish, brown maculations below the sub- 
sutural band and at the periphery of the body 
whorl. 

Description: Shell shiny, of moderate size for 
the genus with 13 whorls in the teleoconch; 
protoconch of IV2 mamillate whorls; outline of 
whorls straight; subsutural band defined by a 
groove and with punctations between the ribs; 
axial ribs sharp, 15 on penultimate whorl, with 
wide interspaces; interspaces with 5 spiral 
grooves not crossing ribs; body whorl with ribs 
fading out at periphery, smooth below; aperture 
quadrate; columella slightly recurved; color 
yellowish with dark-brown maculations between 
white-topped ribs on the subsutural band and at 
the periphery of the body whorl. 

Dimensions: Holotype 36.1 x 6.2 mm; para- 
types from 10.4 x 2.4 to 36.2 x 6.3 mm. 

Type Locality: Reunion Is., Indian Ocean 
(21°06'S, 55°01"E) at 80-83 m depth. 

Type Material: Holotype and 6 paratypes in 
MNHNP; 1 paratype in the Bratcher collection. 

Distribution: From South Africa to Papua 
New Guinea, in depths to 110 m. 

Discussion: This species was originally 
thought to be a color form of T. pertusa (Born, 
1778), until a specimen was examined with its 
mamillate protoconch intact. All specimens with 
the extra row of maculations subsequently ex- 
amined also posessed paucispiral protoconchs. 
T. pertusa has a multispiral protoconch, always 
lacks the additional rows of maculations, and 
grows to a much larger size (97.5 mm) than any 
specimens of this species examined. 



92 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 




L-6 1, Ten-bra riosi Bratcher & Cernohorsky, new species. Holotype LACM no. 1974. 9.8 x 2.5 mrn^ 2 and 6, 

<yra i Hi Bratcher & Cernohorsky, new species. Holotype Natal Museum no. C4715. 97.6 x 14 4 mm. 3 Terebra 

nsis Bratcher & Cernohorsky, new species. Holotype MNHNP. 13.2 x 2.2 mm. 4 and 5, Terebra pseudvpertvsa 

Bratcher & Cernohorsky, new species. Holotype MNHNP. 36.1 x 6.2 mm. 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 93 



Terebra reunionensis 

Bratcher & Cernohorsky, sp. nov. 
(Fig. 3) 

Diagnosis: A small slender brown terebrid 
with no subsutural band and with numerous thin 
riblets. 

Description: Shell small, slender, with 18 
whorls in the teleoconch; protoconch of 3 conical 
whorls; outline of whorls flat; no subsutural 
band; axial ribs faintly curved, equal to the 
width of the interspaces, extending from suture 
to suture, 18 on penultimate whorl; spiral 
threads in interspaces numerous, 10 on penulti- 
mate whorl, lightly crossing ribs, fading below 
periphery of body whorl; aperture elongate; col- 
umella slightly curved; color light brownish 
beige. 

Dimensions: Holotype 13.2 x 2.2 mm; para- 
types 13.6 x 2.5 mm and 12.7 x 2.5 mm. 

Type Locality: Reunion Island, Indian Ocean 
(21°05'S, 55°12'E), in depths of 170-225 m. 

Type Material: Holotype and one paratype in 
the MNHNP; one paratype in the Bratcher coll. 

Distribution: Reunion Island, Indian Ocean, 
in depths of 110 to 225 m. 

Discussion: This is one of the most slender of 
the small Indo-Pacific terebrids. Terebra con- 
tracta (E. A. Smith, 1873) may be separated 
from this species by its brown aperture and col- 
umella, its turrited outline and more elongate 
body whorl. 

There is little variation in the three specimens 
of this species which were collected from two 
localities at Reunion, except that the spiral 
threads on one specimen are missing from the 
anterior third of the last three whorls only. 

Terebra connelli 

Bratcher & Cernohorsky, sp. nov. 
(Figs. 2 and 6) 

Diagnosis: A beige and brown terebrid with 
no spiral sculpture except for a deep subsutural 
groove, and with heavy, crowded posteriorly 
protracted axial ribs both on subsutural band 
and remainder of whorl. 

Description: Shell robust, large for the genus 
(97.6 mm, nearly 4 inches), with 28 whorls re- 
maining, apex missing; outline of whorls shoul- 
dered below convex subsutural band; band with 
round nodes on early whorls, becoming strong 
ribs later, occupying about V3 of the whorl, de- 



fined below by a moderately deep groove; axial 
ribs on remainder of whorl rounded, strong, 
crowded, the same strength and width as those 
on band, straight on early whorls, curved later, 
31 on penultimate whorl; spiral sculpture absent 
except for a narrow, fine cord below the axial 
ribs immediately above the suture; body whorl 
short, with ribs ending abruptly at periphery; 
aperture quadrate; columella recurved; siphonal 
fasciole striate, defined by a keel; color brown- 
ish beige stained with darker areas and with a 
nebulous brown area anterior to periphery of 
body whorl. 

Dimensions: Holotype 97.6 x 14.4 mm; para- 
type 50.5 x 9.0 mm. 

Type Locality: Off Umhlanga Rocks, Natal, 
South Africa, 116 m depth. 

Type Material: Holotype Natal Museum no. 
B6307; paratype Natal Museum no. C4715. 

Distribution: Natal, South Africa. 

Discussion: In both specimens the ribs on the 
band and remainder of the whorl have the ap- 
pearance of polished antique ivory. The only 
species with which this can be compared is 
Terebra pretiosa Reeve, 1842, which also has 
numerous heavy ribs, but that species has longer 
whorls, a flatter subsutural band defined by 
deep punctations, and its color is yellowish beige 
marked with dark-brown maculations. 

This species is named in honor of Dr. Allan 
Connell, who dredged the holotype. 

Terebra riosi 

Bratcher & Cernohorsky, sp.nov. 
(Fig. 1) 

Diagnosis: A very small, cream-colored West- 
ern Atlantic terebrid with purplish brown 
anterior to the periphery of the body whorl and 
a purple-brown subsutural line. 

Syyionymy: 
1984 Terebra doellojuradoi Carcelles, Aubry, Terebridae 

pi. 9, upper left [not Carcelles, 1953]. 

Description: Shell very small (8 to 10 mm) for 
the genus with 8 teleoconch whorls plus a proto- 
conch of 3V2 amber, conical whorls; outline of 
whorls faintly turreted; subsutural band marked 
only by a nebulous purplish brown line on early 
whorls, 2 rows of weak nodes with the nebulous 
line in the center appearing later; no subsutural 
groove; axial ribs sharp, narrower than inter- 
spaces, in early whorls unbroken from suture to 



94 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



suture, subsutural nodes developing later, 15 on 
penultimate whorl; fine spiral grooves evenly 
spaced, 5 on penultimate whorl, not crossing 
summit of ribs; body whorl with axial ribs end- 
ing at periphery, spiral grooves continuing to 
siphonal fasciole, aperture quadrate; columella 
brown, slightly curved; color yellowish cream, 
almost transluscent, with a nebulous purplish 
brown subsutural line which appears to be under 
translucent enamel, light purplish brown 
anterior to periphery of body whorl; columella 
dark-brown. 

Dimensions: Holotype 9.8 x 2.5 mm; para- 
types from 8.1 x 2.3 mm to 10.2 x 2.6 mm. 

Type Locality: Buzios, Cabo Frio, Rio de 
Janeiro, Brazil, intertidal in sand. 

Type Material: Holotype Los Angeles County 
Museum of Natural History no. 1974; 3 para- 
types Museu Oceanografico de Rio Grande no 
21.278; 1 paratype Bratcher coll. 

Distribution: Atlantic coast of central Brazil, 
intertidal to 30 m. 

Discussion: This species has been misiden- 
tified by dealers and Aubry (1984) as Terebera 
doellojuradoi Carcelles, 1953, which has a proto- 
conch of IV2 whorls, a teleoconch with cancellate 



sculpture, a subsutural band marked by puncta- 
tions or square pits between the ribs, and no 
brownish subsutural line nor brownish area 
below the periphery of the body whorl. 

This species is named in honor of Prof. E. C. 
Rios of Brazil, who first brought it to our 
attention. 

Acknowledgments 

We wish to thank Dr. Philippe Bouchet of the 
Museum National d'Histoire Naturelle de Paris, 
Dr. Richard Kilburn of the Natal Museum of 
South Africa, and Prof. E. C. Rios, Museu 
Oceanografico de Rio Grande, Brazil, for the 
loan of material for this study. 

LITERATURE CITED 

Aubry, Umberto. 1984. Terchrulac (Mollusca: (iastrajiuita). 
48 pp., 15 pis. (privately published in Italy). 

Born, I. von. 1778. Index rerum naturalium M asei Caesarei 
\ inilnlinm lists, pars I, Testacea p i slii; 1 458 

Carcelles, Alberto R. 1963. New species of marine gastro- 
pods of the eastern republics of Uruguay and Argentina. 
Zoological Publications of the Museum of Natural History 
of Montevideo (4):1-16, pis. 1-5. 

Reeve, Lovell. 184:2. C'onchologia Systematica or complete 
system of Conchology. Longman, Brown, Green & Long- 
mans, London. 2:1-337, pis. 130-300. 



SUCCINEA VAGINACONTORTA LEE 
(GASTROPODA: PULMONATA: SUCCINEIDAE) 

Dorothea S. Franzen 

Illinois Wesleyan University 
Bloomington, IL 61701 

ABSTRACT 
On the bases of shell characters, geographic distribution, and habitats Succinea 
vaginacontorta Lee is a valid species and not a synonym of Succinea indiana 
Pilsbry. 



Synonymy: 
Succinea vaginacontorta Lee, L951, Occas. Pap. Mus. Zool 
Univ. Mich. No. 533, 1-7, pi. 2, text fig. 1; Miles, L958, 
Univ. Kans. Sci. Bull. Vol. XXXVIII, Pt. 11, No. 24, 
1517 1519, PI. LC, fig. I; Leonard, L959, Handbook of 
opod in Kansas. Mus. Nat. Hist. Misc. Pub. 20, 
>8, pi. 9, fig. 3; Franzen. 1971, Nautilus 84(4), 
131-142, tables 2, figs. 3. 



Succinea Indiana Pilsbry, Hubricht, 1961, Nautilus 72(2), 

insert in reprint, p. 60. 
Succinea indiana Pilsbry, Hubricht. 1985. Fieldiana Pub 

No. 1359: 15, Map p. I 17. 

The employment of anatomical structures of 
soft parts, radulae, pigmentation patterns as 
well as shell characteristics is generally essen- 



Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 95 



tial for accurate identification of species of 
Succineidae. Unfortunately, historically, many 
collectors and authors of species of succineas 
based their descriptions solely on shell char- 
acters. They did not describe, illustrate or 
preserve the soft parts, therefore, we have to 
rely on comparisons of shells with those of holo- 
types and/or paratypes. Some types were cata- 
logued in private collections which in some 
instances cannot be located. 

Pilsbry (1948, p. 818) illustrated the shell and 
reproductive structures of a succineid which he 
identified as a Succinea aurea Lea from Cape 
May, New Jersey. The type locality of the 
species is "Springfield, Ohio." To date I have 
been unsuccessful in locating the holotype and/ 
or paratypes of S. aurea Lea. Pilsbry (ibid) 
placed Succinea Indiana Pilsbry, 1905, into the 
synonomy of 5. aurea Lea. He described only 
the shell and did not illustrate or describe the 
soft anatomy of S. indiana. 

Hubricht collected a live succineid, which he 
identified asS. indiana Pilsbry, from a loess hill- 
side near New Harmony, Indiana, presumably 
the type locality of the species. "Upon dissection 
of the animal it was found to be unrelated to S. 
aurea Lea, in the synonomy of which it was later 
placed by Pilsbry (Pilsbry, 1948). The penis is 
similar to that of Succinea campestris Say, the 
mantle is dark gray without the spots character- 
istic of S. concordialis Gould. Succinea indiana 
must, therefore, be considered a distinct species 
belonging to section Calcisuccinea Pilsbry." 
(Hubricht, 1958, 60-61). Hubricht (1961, 60) 
reported from a later collection he made from 
presumably the type locality of S. Indiana, "A 
careful examination of the anatomy and shell of 
topotypes Succinea indiana showed no charac- 
ter which could be used to distinguish it from S. 
vaginacontorta. The same twisted vagina is 
found in S. indiana. S. vaginacontorta Lee must 
be placed in the synonomy of 5. indiana." 

Pilsbry (1948, p. 817) quotes his 1905 descrip- 
tion of Succinea indiana, "Shell obesely ovate, 
thin, brownish amber or raw sienna colored, the 
apex reddish. Sculpture of fine growth-lines and 
wrinkles, becoming rather coarse wrinkles on 
the last half whorl. Whorls 3V2, very convex, the 
last large and inflated. Aperture large, oblique, 
the outer lip either regularly arcuate or some- 
what flattened in the middle. Columella thin and 



strongly arcuate throughout." 

Because soft parts of the holotype and para- 
types of Succinea indiana Pilsbry have not been 
described or preserved and, therefore, are not 
available for examination, comparisons of that 
species with S. vaginacontorta Lee are here 
based on shell characteristics of the holotype 
and paratypes of S. indiana and topotypes of S. 
vaginacontorta, their habitats and geographic 
distribution. 

Shell Characteristics 

Succinea vaginacontorta Lee, section Cal- 
cisuccinea Pilsbry, 1948. Lee described the shell 
of the holotype, "Shell is dextral, fully devel- 
oped. Whorls, 3, with suture only moderately 
impressed. Whorls which increase proportion- 
ately from the apex to the body whorl with no 
marked discontinuity in size. In life shell is a 
dull, translucent, light, horn yellow with green- 
ish tones. Striae present and well raised (PI. 1, 
Fig. 3). Epidermis of upper whorl eroded away 
revealing dull white deeper layers of shell, 
parietal wall with well-developed callus, cover- 
ing base of slightly curved columella (PI. 1, Fig. 
2). Aperture obliquely ovate with a slight flare 
at base of outer lip. Interior of aperture with a 
thin shiny transparent sheen." (Lee, 1951, 3). 

Significant shell differences of the two species 
can be noted in Fig. 1, and are here listed: 

1. Succinea vaginacontorta is more elongate-ovate than S. 
indiana. S. vaginacontorta attains a height up to 12.3 mm 
(Franzen, 1971, Table I). Height of holotype of S. 
indiana, 11.0 mm. 

2. Nuclear whorl of both species knob-like; that of S. vagina- 
contorta large and more prominent; of S. indiana reddish 
brown. 

3. Spire of S. vaginacontorta more tightly twisted and 
acute-elongate than of S. indiana. First whorl of S. 
vaginacontorta larger than of S. indiana. 

4. Whorls of S. indiana more inflated and shouldered; body 
whorl more inflated, roundly ovate and aperture more 
elongate-ovate than of S. vaginacontorta. 

5. Peristome of S. vaginacontorta sharp, continuous as a 
well-developed callus on body wall and covering the col- 
umella as it ascends. Columella of S. indiana white, re- 
curving as it disappears into ultimate whorl; callus on 
body wall thin. 

6. Periostracum of S. vaginacontorta thin, dull, light horn 
yellow, readily removable exposing the deeper, white 
layers of the shell. Striae heavier and coarser than of S. 
indiana which produce a rough appearance on surface of 
ultimate whorl. Due to the heavy striations the shell, 
when stripped of its periostracum, has a striped appear- 
ance. Periostracum of S. indiana yellow-amber, doesn't 



96 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 





FIG. 1. A, B. Topotype of Succinea vaginacontorta Lee. 
Height, 10.7 mm. C, D. Holotype of Succinea indiana 
Pilsbry. Height, 11.0 mm. 



peel as readily as of S. vaginacontorta; striae fine 
resulting in a shiny, silky surface. 

Habitats and Geographic Distribution 

Type locality of Succinea vaginacontorta Lee, 
SW corner of S 18, T 33 S, R 28 W, Meade Coun- 
ty, Kansas, "... a sagebrush Hat on which hairy 
gramma grass {Bouteloua hirsuta Lag.) was 
growing along a small creek ... It is not subject 
to flood. The nearest permanent water is 
Crooked Creek about one-half mile to the east. 
The hairy gramma grass occurred in thick 
stands with a few small patches between the 
stands. The snails lived on spots of lichens, 
mosses, and occasional liverworts between 
these patches." (Lee, 1951, 1-2). ". . . Succinea 
i-ngitiacoutarta Lee is xerophilous. Its usual 
habitat is a treeless slope of a hillside supporting 
a ground cover of short grass, sagebrush, and 
lichens. This species appears on the surface in 



the summertime after rains have soaked the 
ground. During periods of drought it disappears 
and may not be seen again for months or even 
years." (Franzen, 1971, 132). Average annual 
precipitation of Meade County, Kansas, is 
18.72". (Yearbook of Agri., 1941, 874). 

Succinea vaginacontorta is known from 
localities of the high plains including Meade 
County, Kansas; Brown County, Nebraska; 
Washabaugh County, South Dakota; San Miguel 
County, New Mexico (Franzen, 1971) and later 
from other counties of SW Kansas; Yuma Coun- 
ty, Colorado; Sherman County, Texas; and 
Platte County, Wyoming. 

Succinea indiana Pilsbry was collected by L. 
E. Daniels in 1904 from ". . . just south of New 
Harmony, Posey Co., Indiana, on the hillside 
facing west between the marl cliffs and the 
highway." (Pilsbry, 1948, 817). I have visited the 
site a number of times and have observed 
changes. The hillside supports a growth of 
timber consisting of hardwoods up to its 
western slope. The west end of the hillside has 
been altered since the time Daniels collected the 
succineas. The slope facing the highway has 
been excavated. For a number of years the 
western end of the hill was burned annually 
which controlled the growth of the brush. In re- 
cent (about six or seven) years the area has not 
been burned; the brush has become dense and 
impenetrable. The average annual precipitation 
of Posey County, Indiana, is 42.34". (Yearbook 
of Agri. 1941, 855). The habitat of this site does 
not resemble that of the high plains where S. 
vaginacontorta is known to live. 

The geographic distribution, habitat, and shell 
characters distinguish Succinea vaginacontorta 
Lee from Succinea indiana Pilsbry. S. vagina- 
contorta is, therefore, not a synonym of S. 
indiana but a valid species. 

Acknowledgments 

National Science Foundation Grants-in-Aid 
No's. NSF G18000 and NSF GB2715 provided 
laboratory equipment and supported, in part, 
field studies. I am grateful to Dr. A. Byron 
Leonard for reviewing the manuscript. The 
Academy of Natural Sciences of Philadelphia 
graciously loaned me type specimens of Suc- 
cinea indiana Pilsbrj . 



Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 97 



LITERATURE CITED 

Franzen, Dorothea S. 1971. Anatomy and Geographic Distri- 
bution of the Succineid Gastropod, Sucrinen cagitia- 
contorta Lee. The Nautilus 84(4):131-142. Tables I, II, 
Figs. 1-3. 

Hubricht, Leslie. 1958. Quickella vermeta and Sucdnea 
indiana. The Nautilus 72(2):60-61. 

1961. Eight New Species of Land Snails From 

the Southern United States. The Nautilus 75(l,2):26-32, 
60-63, PI. 4, figs. 1, 2. 
1985. The Distribution of the Native Land Mol- 



lusks of the Eastern United States. Fieldiana, Zoology, 
New Series, No. 24, Publication 1359, Field Museum, 
1-191; Maps 523. 
Lee, C. Bruce. 1951. Sucdnea vaginacontorta (Section Calci- 



succinea), A New Amber Snail from Kansas. Occ. Pap. 
Mus. Zooi. Univ. Mich.. No. 533 (Mar. 20): 1-7, Pis. I, II, 
Text fig. 1. 

Leonard, A. Byron. 1959. Handbook of Gastropods in 
Kansas. Univ. Kans. Mus. Nat. Hist. Misc. Pub. No. 20 
(Nov. 2): 1-224, Pis. 1-11, Figs. 1-87. 

Miles, Charles D. 1958. The Family Succineidae (Gastro- 
pods: Pulmonata) in Kansas. Univ. Kans. Sci. Bull. 38, Pt. 

2, No. 24 (Mar. 20): 1499-1543, PI. 1, Figs. 1-8. 
Pilsbry, Henry A. 1948. Land Mollusca of North America. 

(North of Mexico). Acad. Nat. Sci. Philadelphia Mon. No. 

3, Pt. 2: xlvii & 521-1113, 585 figs. 

Yearbook of Agriculture. 1941. Climate and Man. United 
States Department of Agriculture, U.S. Government 
Printing Office, Washington, D.C.: v-xii and 1-1248. 



A NEW SPECIES OF CORALLIOPHILA 
(GASTROPODA: CORALLIOPHILIDAE) 
FROM SOUTHEASTERN POLYNESIA 



Harald A. Rehder 

Smithsonian Institution 
Washington, DC 20560 

ABSTRACT 
Coralliophila latilirata is described as new from southeastern Polynesia and 
compared with C. bulbiformis Conrad (1837). 



The receipt from M. Jean Trondle of La 
Force, France, of numerous specimens of a 
species of Coralliophila from the shores of Anaa 
Atoll in the Tuamotus, called my attention 
forcefully to the distinctness of a species which I 
had collected earlier in French Polynesia, 
Pitcairn, and Cook Islands, but only in single 
lots or as fragments. A careful comparison of 
material of this species with that of C. bulbi- 
formis Conrad (1837) has revealed not only its 
distinctness, but also that it is found only in a 
rather limited area. 

Coralliophila latilirata, new species 
Figs. 1-3 
Diagnosis: Shell of moderate size, 15-30.75 
mm in length, globose to broadly ovate, with 
numerous crowded, broad, scabrous, flattened 
spiral cords; aperture deep lavender to pale pur- 
ple, occasionally white. It is close to bulbiformis 
Conrad, (1837) but is more inflated, with a lower 



spire, and broad, crowded, flattened, spiral 
cords. 

Range: Southern Cooks, western Austral 
Islands, Society Islands, Tuamotus, and 
Pitcairn Group (Fig. 4). 

Description: Shell stout, thick-shelled, globose 
to broadly ovate, white, adults from 15 to 30.75 
mm in height, width from 70% to 92% of height. 
Protoconch polygyrate, conical, pinkish, about 
4% whorls; first whorl apparently smooth (par- 
tially-broken off), following whorls with a nodu- 
lose spiral keel below a sloping shoulder with 
axial riblets which are somewhat prosocline to 
opisthocyrt'; a second keel gradually forms 
above the main keel resulting in the last 11/5 
protoconch whorls bearing two keels made 
nodulose by the axial riblets. Postnuclear whorls 
about 6 (earliest whorls generally worn or 
covered with calcareous deposit), early ones 



amewhat inclined forward to curved backwards" -Editor. 



98 THE NAUTILUS 



October 31, 1985 



Vol. 99(4) 




FIGS. 1-3. Cnnilliiiphiltt Ititilirata n. sp. 1 and 2 apertural and top views of the holotype, USNM 731531, 
height 25.22 m. 3, apertural view of paratype, USNM 845460, height 30.78 mm. 




FIG. 4. Map showing distribution of Coralliaphila latiliralu n. sp. (circles), and Coralliophila buMfornns Conrad (stars). 



strongly carinate, with four broad lirae, finely 
scalloped, separated by narrow grooves and 
crossed by broad rounded axial ridges, render- 
ing the surface of the whorls wavy; in later 
whorls the axial ridges become broader and 
lower, and the spiral ridges more irregularly 
nodose, or flattened, the separating grooves 
usually very narrow; the penultimate whorl 



generally with five spiral ridges; body whorl 
evenly convex, with about 17 irregularly flat- 
tened ribs that are axially and densely lamellate; 
the lamellae generally fused together especially 
on the prosocyrt axial ridges that number thir- 
teen on the body whorl of the holotype. but may 
be fewer and broader on other specimens; in 
worn specimens the axial lamellae that compose 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 99 



the broad spiral lirae may be more or less 
obscure due to fusion and some erosion. Aper- 
ture oval, ending anteriorly in a short to 
moderately long, curved, narrowly attenuated 
canal; outer lip made finely crenulate by the 
ends of the external spiral ridges; columella and 
interior of aperture deep- to pale-lavender, (light 
grayish purplish red to grayish purplish red: 
Kelly & Judd, 1965); a strong lamellose fasciole, 
surrounding a broad to moderately narrow false 
umbilicus, terminates in the end of the siphonal 
canal. 

Habitat: Host unknown. Found alive under 
and near coral in 40-55 ft. and dredged in 50-56 
fathoms. Found in stomachs of fish (Coris 
aygula) caught in 50-100 ft. 

Type Locality: Oeno, Pitcairn Islands. 

Material: Holotype: lagoon, northshore, in 1-6 
ft. on hard pan bottom, Oeno, Pitcairn Islands, 
collected by H. A. Rehder, 18 December 1970 
(USNM 731531). Paratypes-COOK ISLANDS: 
W. of Avatiu, Rarotonga in 45 m (USNM 
732270); E of Avarua, Rarotonga, in 25 m 
(USNM 732262); AUSTRAL ISLANDS: NW of 
Moerai, Rurutu, in 40-50 m (USNM 732217); 
north coast, Tubuai, 25 m (USNM 732294); 
SOCIETY ISLANDS: E side Taunoa Pass, 
Arue, Tahiti (USNM 668779); TUAMOTUS: 
NW side Puka Puka (USNM 789879); NW end of 
lagoon, Anuanuraro (USNM 725347); dead on 
beach, Anaa (USNM 845460; Colin. Trondle); 
dead on beach, Raroia (USNM 697956, 697685, 
698743). PITCAIRN ISLANDS: off NW corner, 
in 100-124 m Pitcairn (USNM 789442); off Boun- 
ty Bay in 15-16.7 m Pitcairn (USNM 731663); W 
of Bounty Bay, in 30 m (USNM 731831); off 
Christian's Point, in 15 m (USNM 731765). 

The two lots from the Cook Islands, the lot 
from Rurutu, and two of the lots from Pitcairn 
(USNM 731831, USNM 731765) all consist of 
fragments found in the gut of specimens of the 
fish, Coris aygula, speared at the depths 
indicated. 

Measurements (mm): 



USNM 731531 holotype 
Trondle Colin, paratype 
USNM 731663 paratype 
Trondle Colin, paratype 
Trondle 789453 paratype 
Trondle 725347 paratype 
USNM 789879 paratype 



height 


width 


25.22 


20.18 


30.75 


25.05 


21.83 


20 26 


19.18 


16.85 


18.08 


14.64 


16.32 


14.34 


15.05 


13.05 



Twenty-five specimens were measured and 
found to range between 30.75 to 15.05 mm in 
height and 25.05 to 13.05 mm in width; the 
average height is 21.72 mm and the average 
width is 18.14 mm. 

Etymology: From the Latin, meaning "with 
broad ridges." 

Discussion: This species is closest to Corallio- 
phila bulbiformis Conrad, 1837, but is less 
elevated, with a low broad spire with flattened 
whorls, the spiral lirae less numerous, broader, 
flattened, and made nodulose by more or less 
worn lamellae, and the axial ribs lower, less 
prominent than in most specimens of bulbi- 
formis. 

Good illustrations of C. bulbiformis Conrad 
may be found in Cernohorsky 1978 (pi. 21, fig. 4) 
and Kira, 1962 (p. 68, pi. 26, fig. 6). C. bulbi- 
formis is identified as C. costularis Lamarck, 
1816, by Salvat and Rives, 1975 (p. 310, fig. 
190), but the latter is a narrower, fusiform 
species that is found from East Africa to the 
Ryukyus. Similarly, C. bulbiformis is synony- 
mized by Kay in her Hawaiian Marine Shells 
(Kay, 1979, p. 255, pi. 90B) under C. erosa 
(R(')ding), but an examination of the description 
and figures in Chemnitz on which Roding based 
his name shows that erosa is the species that 
Kay describes and figures (Kay, 1979, p. 255, 
fig. 90A) under C. dorbignyana (Petit, 1851), a 
junior synonym of erosa. 

Coralliophila bulbiformis Conrad varies con- 
siderably in shape, from rather elevated with 
strongly convex, more or less angled whorls 
with consequently indented sutures to ovate 
species with only slightly convex whorls and less 
indented whorls. The latter form is common in 
the Hawaiian Islands, while the Marquesan 
specimens are more elevated with convex 
whorls, as are most of those in the rest of the 
range of the species. It is a distinct species, and 
not a subspecies of C. erosa, as Abbott and 
Dance (1982, p. 155) cite it. 

This new species is restricted, as far as we 
now know, to the Cook Islands and French Poly- 
nesia, including the Pitcairn Islands (Fig. 4). It 
has however not been found in the Marquesas, 
where C. bulbiformis occurs, or in Rapa. C. 
bulbiformis is found from the Ryukyus and 
Philippines eastward to Hawaii, the Marquesas 
Islands, Samoa and New Caledonia. 



ion THE NAUTILUS 



October 31, 1985 



Vol. 99(4) 



LITERATURE CITED 

Abbott, R. Tucker and S. Peter Dance. 1982. Compendium 

oj'Si'iishrlls. New York, 410 pp. 
Cernohorsky, Walter 0. 1978. Tropical Pacific Marine 

Shells. Sydney: New York, 352 pp. 
Conrad, T. A. 1937. Descriptions of new marine shells from 

upper California, collected by Thomas Nuttall, Esq. J. 

Acad. nat. Sci. Philadelphia 7:227-268, pi. 17-20. 
Kay, E. Alison. 1979. Hawaiian Marine Shells. B. P. Bishop 



Museum Spec. Publ. 64(4), 671 pp. 
Kelley, K. L. and D. B. Judd. 1965. The ISCC-NBS Method 

of Designating Colors and a Dictionary of Color Names. 

Nat. Bur. Standards Circular 553, 163 pp. 
Kira, T. 1962. Shells of the Western Pacific in Color. Osaka, 

224 pp. 
Sal vat, Bernard and Claude Rives. 1975. Coquillages de 

Polynesie. Papeete, 391 pp. 



NATIVE FRESHWATER MUSSELS (UNIONACEA) AS FOULING 
AGENTS IN ELECTRICAL GENERATING PLANTS 



Raymond W. Neck 

Texas Parks and Wildlife Department 

4200 Smith School Road 

Austin, TX 78744 

ABSTRACT 

The occurrence of native freshwater mussels (Unionacea) as fouling agents in 
the water supply system of an electrical-generating plant is reported. Details of 
the reported problem and discussion of the likelihood of similar occurrences in 
additional generating plants are presented. 



While the Asiatic clam, Corbicula fluminea, is 
well-known as a fouling agent in electrical gen- 
erating plants (Mattice, 1977; Smithson, 1981), 
native unionids have not been implicated in 
similar situations. Absence of unionids in water 
distribution systems has been attributed to lack 
of byssus attachment (see Ingram 1953). Herein 
I record an example of both Corbicula and 
native unionids as fouling agents in a cooling 
water supply main for a lignite-fired electrical 
generating plant. The purposes of this study 
were (1) to understand factors significant in this 
fouling example and (2) to determine if this was 
an isolated incident or a forerunner of future 
problems at other power plants. 

Alcoa Lake is a 5972-hectare reservoir located 
11km southwest of Rockdale, Milam Co. , Texas. 
The impoundment was created in 1953 on Sandy 
Creek, a tributary of East Yegua Creek in the 
Brazos River drainage. The limited surface 
runoff water is supplemented by an aqueduct 
which transports water approximately 20.5 kilo- 
meters from the Little River, also in the Brazos 
drainage. The unionids reported below probably 



originated from the Little River, although some 
stocking of fish has occurred in Alcoa Lake. 

Jule Frankeny of International Generating 
Corporation, operator of the Sandow Power 
Plant at Alcoa Lake, informed me that a number 
of clams had been forced under pressure in 
August 1983 from a service line (off the supply 
main) which had been partially blocked. Inspec- 
tion of recovered clams revealed Anodonta 
grandis, Cyrtonaias berlandieri and Corbicula 
fluminea; all three species have been reported 
from the Brazos drainage (Strecker 1931; 
Fontanier 1982). These clams were recovered 
from a 14-inch diameter pipe located four feet 
below ground surface. To reach this pipe, the 
individuals recovered had passed through an 
initial traveling screen (12.8 mm mesh), large 
pump, booster pump (19.5 mm bore), and 
another strainer (4.8 mm mesh). 

Two water supply mains transport water from 
Alcoa Lake to the Sandow plants. Both mains 
are of equal size (initially 78" diameter), but one 
main supplies two plants while the second only 
supplies one plant (a planned fourth plant was 



Vol. 99 (4) 



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THE NAUTILUS 101 



never built). Unionids were found only in a ser- 
vice line off the second main where decreased 
water velocities apparently allowed sediment 
and clams to accumulate to a degree that water 
flow was eventually restricted. 

A typical recovered A. grandis shell was 127 
mm in length and 72.2 mm in height. This "long, 
low" phenotype corresponds to the nominate 
variety. The shell is highly polished, especially 
on the older part of the shell. Dark rings may 
represent annuaj growth rings which are gen- 
erally faint to absent on most Texas shells. Ring 
production could be due to differences in growth 
rate due to variations in water temperature 
and/or food supply. Total number of rings is ten. 

Cyrtonaias berlandieri from this supply main 
were small and rather thick-shelled but ap- 
peared similar to examples from surface water 
populations from central Texas. Nacre color was 
light pinkish purple; typical shell height and 
length was 73.0 mm and 51.0 mm, respectively. 

Corbicula fluminea shells were small with the 
largest measuring 28.45 mm in length; all shells 
were of the "white morph." 

The only similar example recorded in the liter- 
ature was by Button (1900). Two examples of 
Margaritifera margaritifera var. falcata which 
were collected in a water tunnel near Santa 
Cruz, California. The shells were found 700 feet 
from the mouth of the tunnel at a depth of 300 
feet. Button (1900) did not state that the ex- 
amples were alive, but he described the shells as 
"unusually large and thin, the nacre being richly 
colored." 

Occurrence of unionids in water lines of an 
electrical generating plant raises questions 
concerning the likelihood of these clams becom- 
ing major problems in such plants. The exist- 



ence of this problem at the Sandow complex 
could be significant because these plants were 
the first lignite-fueled electric generating units 
in Texas (Espey, Huston and Associates 1983: 
60). Sandow #1 and #2 went on line in 1953 with 
Sandow #3 becoming operational in 1954. Exist- 
ence of clams only in the line servicing #3 
indicates that the occurrence of unionids as a 
fouling agent in electric generating plants prob- 
ably will be a minor problem. The passage of 
young unionids through the screening mecha- 
nisms is likely to be a low probability event, 
especially in contrast to passage of minute 
larval forms of Corbicula fluminea. Survival of 
young unionids which do pass through these 
screens is unlikely except in those pipes with low 
velocity flows which do not exceed appropriate 
entrainment velocities. 

I thank Jule Frankeny and Pete Goggin for 
supplying the clams and information on the 
power plants. 

LITERATURE CITED 

Button, F. L. 1900. Unionidae in a tunnel. The Nautilus 
13:130. 

Espey, Huston and Associates, Inc. 1983. Impacts of lignite 
development of Texas. Texas Energy & Natural Resources 
Advisory Council, EDF-091:l-89. 

Fontanier, C. E. 1982. The distribution of Corbicula 
(Bivalvia: Corbiculidae) in the Brazos river system, Texas, 
25 August - 12 November 1980. Texas J. Sci. 34:5-15. 

Ingram, W. M. 1956. Snail and clam infestations of drinking- 
water suppliers. J. Arner. Water Works Assoc. 48: 
258-268. 

Mattice, J. S. 1977. Interactions of Corbicula sp. with power 
plants. Pp. 119-138, Proc, First International Corbicula 
Symposium (J. C. Britton, ed.), Texas Christian Univ. 
Research Foundation, Fort Worth, 313 pp. 

Smithson, J. A. 1981. Control and treatment of Asiatic 
clams in power plant intakes. Proc. Amer. Power Con- 
ference 43:1146-1151. 



ILLUSTRATED CATALOGUE OF LATIAXIS AND 
ITS RELATED GROUPS FAMILY CORALLIOPHILIDAE 

By Dr. Sadao Kosuge 

Expected U.S. availability: November, 1985 

Most complete coverage of the family Coralliophilidae. Over 200 species illustrated in 24 color and 26 B/W plates, 
including many holotypes. Brief description, synonyms and geographical distribution for each species are covered in 50 
pages of text in English. Paperbound, 7"x 10". You may order from your favorite book dealer or send $22.50 for your 
copy to Donald Dan, 2s649 Avenue Normandy East, Oak Brook, IL 60521. Price includes domestic U.S. postage. (For 
foreign orders, add $2.00 for seamail and $12.00 for airmail). 



102 THE NAUTILUS 



October 31, 1985 



Vol. 99(4) 



TERAMACHIA DUPREYAE NEW SPECIES, 

FROM OFF WESTERN AUSTRALIA 

(GASTROPODA: VOLUTIDAE) 



William K. Emerson 

Department of Invertebrates 

American Museum of Natural History 

New York, NY 10024 

ABSTRACT 
Teramachia dupreyae, a new species from deep water 200 miles NW of Broome, 
Australia, is described and compared with related species of the volutid subfamily 
Calliotectinae. In addition to this newly described taxon, the following species are 
recognized in the genus Teramachia: tibiaeformis Kuroda, 1931, dalli (Bartsch, 
1942), smithi (Bartsch, 1942), johnsoni (Bartsch, 1942), mirabilis (Clench and 
Aguayo, 1941), and shinzatoensis MacNeil, 1961. 



Through the kind offices of Robert and 
Dorothy Janowsky, proprietors of Mai de Mer 
Enterprises of West Hempstead, New York, the 
presence of recently obtained specimens of this 
interesting discovery were brought to my atten- 
tion. I am pleased to describe this new western 
Australian volute in honor of Constance Duprey 
of Nashville, Tennessee, who generously sub- 
mitted her specimens for study and donated the 
holotype to the American Museum of Natural 
History (AMNH). 

A total of seven species, including the new 
taxon described herein, are recognized in the 
genus Teramachia at the present time. Five liv- 
ing and one extinct species are known from the 
western Pacific. A single extant species is 
reported from the western Atlantic. 

The previously known species-group taxa 
referable to Teramachia are listed in sequence 
of publication: 

1. Teramachia tibiaeformis Kuroda, 1931, pp. 
45-47, figs. 2, 3; Kuroda and Habe, 1950, pp. 36, 
37, pi. 5, fig. 1, text fig. 5 (operculum), "Tosa in 
100 fms." [182 meters]; Habe, 1952, p. 132, fig. 
12 (radula); Azuma, 1960, p. 48, pi. 2, fig. 9, off 
Tosa, in 182 meters; Kira, 1962, p. 92, pi. 33, fig. 
4 (illus. in color), "Honshu and southwards, rare- 
ly found at 100-150 fathoms depth" [182-274 
meters); Shikama, 1963, p. 97, pi. 79 (illus. in 
color), Hyuga, Japan; Weaver and duPont, 
p. 179, pi. 76 E, F (illus. in color), text fig. 
41b (operculum); Abbott and Dance, 1982, p. 224 
(illus. in color). Type locality: "< H'f Kii". [Honshu, 



Japan]. The type species of Teramachia Kuroda, 
1931. This well-known, small species (length to 
90 mm) seems to be restricted to southern 
Japanese waters. The holotype is in The 
Academy of Natural Sciences of Philadelphia. 

2. Teramachia mirabilis (Clench and Aguayo, 
1941), pp. 177, 178, pi. 14, fig. 2; Clench and 
Turner, 1964, p. 177, pi. 114 (holotype); Weaver 
and duPont, 1970, p. 178, pi. 76 A," B (holotype, 
illus. in color). Type locality: "off Matanzas, 
Matanzas Prov., Cuba,... in 289 fathoms [528 
meters]". The type species of Howellia Clench 
and Aguayo, 1941. 

3. Teramachia dalli (Bartsch, 1942), pp. 10, 
11, pi. 2, figs. 1 (operculum), 4; Weaver and 
duPont, 1970, p. 177, pi. 75 E, F (holotype, illus. 
in color), text fig. 41a (operculum); Lan, 1980, p. 
63, pi. 25, figs. 55, 55a, "SW off Taiwan"; 
Bouchet, 1981, p. 10, illus., NW of Mindoro, 
Philippines, in 680-770 m; Abbott and Dance, 

1982, p. 224 (holotype, illus. in color); Okutani, 

1983, p. 10, pi. 33, fig. 5, "Taiwan"; Wells, 1983, 
p. 5, illus., off Port Hedland, northwest 
Australia, in 376 meters. Type locality: "off 
Cape Santiago, Luzon, [Philippines], in 394 
fathoms [720 meters]." The type species of 
Prodallia Bartsch, 1942. This stout but thin 
shelled species attains 175 mm in length. The 
prominent suture is deeply grooved and off-set 
by regular and evenly spaced ribs, which are ter- 
minally cuspate at the summit. The periostra- 
cum on fresh specimens is a blackish brown. 

4. Teramachia smithi (Bartsch, 1942), p. 11, 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 103 



pi. 2, fig. 5; Weaver and duPont, 1970, pp. 178, 
179, pi. 76 C, D (holotype, illus. in color); 
Greene, 1975, p. 12, illus., "10 miles southeast 
Taghilaran, Bono], Philippines, trawled alive"; 
Clover, 1978, pp. 60, 61 (illus. in color), "Off 
Boho, Philippines, in 200 meters"; Abbott and 
Dance, 1982, p. 224 (holotype, illus. in color). 
Type locality: "off Balicasag Island, Bohol 
[Philippines], in 439 fathoms [802 meters]". This 
large shell (length 173.5 mm, Duprey coll. A429) 
is characterized by the narrow spire, inflated 
body whorl, with a wide aperture and a widely 
flaring outer lip. The periostracum is a tannish 
brown. 

5. Teramachia johnsoni (Bartsch, 1942), p. 12, 
pi. 2, fig. 3; Weaver and duPont, 1970, p. 178, 
pi. 75 G, H (holotype, illus. in color); Rehder, 
1972, p. 8, figs. 3, 7; Lan, 1980, p. 63, pi. 25, 
figs. 54, 54a, "SW off Taiwan" (not T. tibiae- 
formis); Okutani, 1983, p. 10, pi. 33, fig. 4, 
"Cebu, Philippines" (not T. tibiaeformis), fig. 6, 
"South China Sea" (not T. smithi) and fig. 7, 
"Taiwan". Type locality: "3V 2 miles NW of 
Cagayan Island, [Philippines], in the northern 
Sulu Sea, in 344 fathoms [628 meters]," fide 
Rehder, 1972, p. 8. Originally described on the 
basis of an immature specimen, Rehder (1972, 
pp. 8, 9, figs. 3, 7) subsequently described an 
adult specimen of this narrowly and elongately 
fusiform species, which is known to attain 145 
mm in length. The light brown periostracum 
covers a grayish to tannish shell with the suture 
stained a darker gray. The outer lip is strongly 
arcuate. Populations from the Formosa Strait 
were afforded subspecific recognition by 
Rehder; see T. j. williamsorum, infra citato. 

6. Teramachia shinzatoensis MacNeil, 1961, p. 
96, pi. 9, fig. 1; Rehder, 1972, p. 8, figs. 5, 6 
(holotype). Type locality: "Shinzato tuff 
member, [Neogene, Okinawa, Japan]". This 
small (length 69.8 mm), Mio-Pliocene fossil is 
compared with T. johnsoni by MacNeil (1961, op. 
tit.) and Rehder (1972, op. tit). 

7. Teramachia johnsoni williamsorum. 
Rehder, 1972, pp. 8, 9, figs. 1, 2, 4; Abbott and 
Dance, 1982, p. 224 (holotype, illus. in color). 
Type locality: "30 miles south of Tung-Chiang, 
Taiwan, in 150 fathoms [274 meters]". All the 
specimens I have examined of this form are 
from the Formosa Strait. Abbott and Dance (op. 
cit.) consider this taxon to be an infrasubspecific 



form of T. johnsoni Bartsch. The available data 
suggest that Rehder's taxon is conspecific with 
T. johnsoni. As in the new species, shell dimor- 
phism is expressed by a stout form (Rehder, 
1972, figs. 1, 4, holotype of T. j. williamsorum) 
and a slender form (Rehder, 1972, figs. 3, 7). 

Family Volutidae Fleming, 1822 

Subfamily Calliotectinae 

Pilsbry and Olsson, 1954 

Genus Teramachia Kuroda, 1931 

Teramachia Kuroda, 1931, p. 45. type species by monotypy, 
Teramachia tibiaeformis Kuroda, 1931, pp. 45-47, figs. 2, 
3, off Kii, Japan. 

Howellia Clench and Aguayo, 1941, p. 177, 
with its type species by monotypy, Howellia 
mirabilis Clench and Aguayo, 1941, pp. 177, 
178, pi. 14, fig. 2, off Cuba, in 285 fathoms [520 
meters], was based solely on the holotype, with- 
out knowledge of the soft parts and operculum, 
and was provisionally placed in the Fasciolari- 
idae. Clench and Turner (1964, p. 178, pi. 114) 
subsequently assigned Howellia to the Voluti- 
dae, subfamily Calliotectinae, following Pilsbry 
and Olsson (1954, p. 19). Clench and Turner (op. 
tit.) noted the close resemblance in shell mor- 
phology of the type species to the genus Tera- 
machia. The western Atlantic T. mirabilis does 
recall examples of T. tibiaeformis from Japan, 
but differs in having the strong axial sculpture 
carried on to the body whorl. A more precise 
systematic assessment of Howellia must await 
knowledge of the soft parts and the radular 
characters of the type species. 

Prodallia. Bartsch, 1942, p. 10, with its type 
species by original designation, Prodallia dalli 
Bartsch, 1942, p. 10, off Luzon, Philippines, ex- 
Bartsch ms., was introduced in a 20-page 
brochure circulated at a banquet in honor of 
William Healey Dall, on April 21, 1915. Because 
the banquet brochure was not available to the 
general public, these taxa were not nomencla- 
turally available until 1942 when Bartsch first 
validly proposed the names. 

Kuroda (1931, p. 47) provisionally placed the 
genus Teramachia in the Volutidae largely on 
the basis of shell and opercular morphology. 
This familial assignment was retained by 
Kuroda and Habe (1950, p. 36). Subsequently, 
Habe (1952, p. 132, fig. 12) figured the rachidian 
teeth of T. tibiaeformis, without comment. 



104 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



Pilsbry and Olsson (1954, p. 19) included 
Ti nimtirhiti (with ['nxlallin in synonymy) in 
their volutid subfamily Calliotectinae. They il- 
lustrated a tricuspid rachidian tooth (Pilsbry 
and Olsson, 1954, pi. 3, fig. 16) of the type 
species of Calliotectum Dall, 1890, which has 
rachidian dentition similar to that illustrated by 
Habe (1952, op. tit.) for T. tibiaeformis. The 
radular and opercular characters of Teramachia 
tibiaeformis strongly indicate placement of this 
genus in the Volutidae (Weaver and duPont, 
1970, p. 176; Render, 1972, p. 7; Cernohorsky, 
1973, p. 127; Emerson and Old, 1979, p. 11; 
Quinn, 1981, p. 73), although some authors have 
assigned Teramachia to the Turbinellidae (olim 
Xancidae) largely on the basis of shell mor- 
phology (Bayer, 1971, p. 195; Abbott and Dance, 
1982, p. 224). 

Rehder (1972, p. 7) reported the presence of 
two oblique folds on the columella of immature 
specimens of T. tibiaeformis and T. johnsoni, 
which become obscure in the adult stage. These 
folds are weakly developed. None of the speci- 
mens I have examined of the species herein 
referred to Teramachia possesses columellar 
plications. Taxa with columellar plaits, which 
were previously assigned to the calliotectine 
volutes, are now placed in the Turbinellidae 
(Rehder, 1967, 1972; Cernohorsky, 1973; and 
Quinn, 1981). This includes Prodallia barthelowi 
Bartsch (1942, pp. 12, 13, fig. 2) from the 
Philippines. 

The new species of Teramachia is one of many 
new or otherwise interesting deep-water species 
recently obtained by shrimp boats trawling off 
the northwest coast of Australia; see Davis and 
Ward (1984). Kosuge (1985) lists and illustrates 
some of these findings in a preliminary report 
on the mollusks. 

Teramachia dupreyae new species 

Figs. 1-8 
Teramachia aff. T. dalli (Bartsh [sic], 1942), Slack-Smith, 

1980. p. 1, illus., "SW of Cape Leeuwin, W. Australia, in 

488-496 m." Not Teramachia dalli (Bartsch, 1942). 
7'i in much in johnsoni (Bartsch. 1942), Kosuge, 1985, p. 58, 

pi. 23, fig. 1 , off the northwestern coast of Australia. Not 

/' rii machia johnsoni (Bartsch, 1942). 

Diagnosis: Shell large for genus, exterior a 
tannish white, aperture a glossy white, suture 
and anterior portion of columellar wall stained a 
brownish lavender; periostracum inconspicuous, 



thin, yellowish buff. The darkly colored sutural 
line against the light color of the shell im- 
mediately distinguishes this elegant volute from 
its congeners. 

Description: Shell large, attaining 195+ mm 
in length, slenderly elongate fusiform. Proto- 
conch missing; remaining whorls of holotype 
IOV2. Lined suture narrow, canaliculate on early 
whorls, with axial ribs, numbering 33 to 37 on 
last completely ribbed whorl; ribs obsolete on 
lower portion of antepenultimate whorl and 
wanting on the penultimate and body whorls, on 
which irregular growth lines occur. Aperture 
elongate, outer lip flaring, edge thin; anal sulcus 
with narrow sinus at juncture with suture; 
anterior siphonal canal widely open; parietal lip 
thinly glazed; columella without plications, and 
weakly folded. Operculum typical for the genus 
(Kuroda and Habe, 1950, p. 46, fig. 5). Soft parts 
not preserved. Color, see Diagnosis above. 

Shell dimorphism is characterized by slender 
individuals (holotype, here illustrated, figs. 7, 8 
and paratypes C and D) and a shorter, inflated 
form (paratype A, here illustrated, figs. 3, 4). 

Measurements: Holotype, 185 mm in height, 
46 mm in width; paratype A, 145 mm in height, 
48.5 mm in width; paratype B, 153 mm in 
height, 44 mm in width; paratype C, 192 mm in 
height, 48.7 mm in width; paratype D, 197 mm 
in height, 42.5 mm in width; paratype E, 184.2 
mm in height, 42.8 mm in width; and paratype 
F, 166 mm in length, 39.9 mm in width. 

Type locality: 200 miles NW of Broome, 
Australia off McDonnell Reef in 400 meters, 
February 1985. Type specimens: holotype, 
AMNH 213477 (figs. 7, 8); paratypes A (figs. 3, 
4, 6) and B (figs. 1, 2, 5) and C from type locality, 
Constance Duprey collection; paratype D, 
AMNH 213438, here transferred to the Western 
Australian Museum, Perth, from 200 miles NW 
of Broome, between Rowley Shoals and Scotts 
Reef, in 450 meters; paratype E, AMNH 
214367, off Broome, in 184 meters; and 
paratype F, AMNH 214368, off Port Hedland, 
NW Australia, in 166 meters. 

Remarks: Of the nominal species of Tera- 
machia, the present species most closely resem- 



FIGS. 1-8. Teramachia dupreyae new species. 1, 2, 
Paratype B. 3, 4, Paratype A. 5, 6, enlarged early whorls, 5, 
Paratype B; 6, Paratype A. 7. 8, Holotype, AMNH 213477. 
1-4, 7, 8 approximately x 2 h; 5, 6 approximately x 1.5. 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 105 




106 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



bles in general appearance T. johnsoni, which 
differs in having the body whorl and penulti- 
mate whorl purplish gray, the early whorls 
yellowish white or white, and the outer lip a 
grayish purple with a brownish margin inside 
the whitish edge of the lip (Rehder, 1972, p. 9). 
In T. tibiaeformis, a dark spiral band appears 
below the suture on the body whorl and penulti- 
mate whorl of some specimens (cf. Abbott and 
Dance, 1982, illus. on p. 224). In T. dupreyae 
new species, the spiral coloration is restricted to 
a thin brownish lavender line within the suture 
(see figures herein). 

Specimens of the new species from the conti- 
nental slope off northwest Australia were 
previously recorded and illustrated by Slack- 
Smith (1980, p. 1), who compared her specimen 
with Teramachia dalli (Bartsch), and by Kosuge 
(1985, pi. 23, fig. 1), who referred his to T. 
johnsoni (Bartsch). Teramachia dalli is also 
reported from off the northwest coast of 
Australia in moderate depths (Wells, 1983, p. 5, 
illus.); Kosuge, 1985, p. 59, pi. 23, fig. 6). An 
additional specimen of T. dalli was trawled, in 
March 1985, off McDonnell Reef, 200 miles NW 
of Broome, Australia and was examined by me 
courtesy of Constance Duprey. This dark- 
colored species differs from the present species 
in the presence of stronger, axial ribs, which ex- 
tend to upper part of the body whorl, and in the 
development of a deeply and broadly channeled 
suture. 

Acknowledgments 

In addition to Constance K. Duprey and Dot 
and Bob Janowsky, I should like to thank my 
AMNH colleagues for their contributions to this 
study: Walter E. Sage III for advice and techni- 
cal assistance, Susan Klofak for specimen 
preparation, Peter J. Harries for the photo- 
graphy, and Stephanie Crooms for word- 
processing the manuscript. 

Dr. Richard S. Houbrick of the National 
Museum of Natural History, Smithsonian In- 
stitution, and Mr. Russell H. Jensen of the 
Delaware Museum of Natural History kindly 
lent me specimens from their respective collec- 
tions for study. Mrs. Gloria Scarboro of Indian 
Harbour Beach, Florida, generously donated 
Paratype D to the collection of the AMNH. Mr. 
Donald H. Y. Dan of Oak Brook, Illinois, and 



Mr. John Landin of Palos Park, Illinois, kindly 
provided specimens for study. 

LITERATURE CITED 

Abbott, R. T. and Dance, S. P. 1982. Compendium of Sea- 
shells, New York, 411 pp., illus. 

Azuma, M. 1960. A catalogue of the shell-bearing Mollusca of 
Okinoshima, Kashiwajima and the adjacent area (Tosa 
Province) Shikoku, Japan., 102 + 17 pp., 5 pis., 2 text figs. 

Bartsch, P. 1942. Some deep-sea Philippine volutids. The 
Nautilus 56(1):9-13, pi. 2. 

Bayer, F. M. 1971. New and unusual mollusks collected by 
R/V John Elliott Pilsbury and R/V Gerda in the tropical 
western Atlantic. Bull. Mar. Sci. 21(l):lll-236, figs. 
1-72. 

Bouchet, P. 1981. Oceanographic expedition at Lubang 
Island, 1980. Carfel Philippine Shell News 3(2):3, 4 and 10, 
10 figs. 

Cernohorsky, W. O. 1973. The taxonomy of Benthovoluta 
hilgendorfi (Von Martens) and allied turbinellid genera. 
(Mollusca: Volutacea). Rec. Auckland Inst. Mus. 10: 
123-131, 16 figs. 

Clench, W. J. and Aguayo, C. G. 1941. Notes and descrip- 
tions of new deep-water Mollusca obtained by the 
Harvard-Havana Expedition off the coast of Cuba. IV. 
Mem. Soc. CubanaHist. Nat. 15(2):177-180, pi. 14. 

Clench, W. J. and Turner. R. D. 1964. The subfamilies 
Volutinae, Zidoninae, Odontocymbiolinae, and Calliotec- 
tinae in the western Atlantic. Johnsonia 4(43):129-180, 
pis. 80-114. 

Clover, P. W. 1978. Smith's volutas. Shell Collector (Ft. 
Lauderdale, Florida), no. 1, pp. 60, 61, illus. 

Davis, T. L. 0., and Ward, T. J. 1984. CSIRO finds two new 
scampi grounds off the North West shelf. Australian 
Fisheries 43(8):41-45. 

Emerson, W. K. and Old, W. E., Jr. 1979. Scaphella con- 
toyensis, a new volutid (Gastropoda) from east Mexico. The 
Nautilus 93(1):10-14, 7 figs. 

Greene, J. 1975. A long-lost' volute. Hawaiian Shell News, 
23(12):12, 1 fig. 

Habe, T. 1952. Pholadomyidae, Clavagellidae, Pandoridae. 
Juliidae and Condylocardiidae in Japan. Illustrated 
Catalogue of Japanese Shells, No. 18, pp. 121-132, pi. 18, 
28 text figs. 

Kira, T. 1962. Shells of the Western Pacific in Color. Osaka, 
i-ix + 1-224, pis. 1-72. 

Kosuge, S. 1985. Noteworthy Mollusca from north-western 
Australia (1), (Preliminary report). Bull Inst. Malac. Tokyo 
2(3):58-59, pis. 22, 23. 

Kuroda, T. 1931. Two new species of Volutacea. Venus 3(1): 
45-49, 3 figs. 

Kuroda, T. and Habe, T. 1950. Volutidae in Japan. Illus- 
trated Catalogue of Japanese Shells, No. 5, pp. 31-38, pis. 
5-7, 6 text figs. 

Lan, T. C. 1980. Rare Shells of Taiwan in Color. Taipei, pp. 
1-144, 63 pis. 

MacNeil, F. S. 1961. Tertiary and Quaternary gastropods of 
Okinawa. U.S. Geol. Surv. Prof. Paper 339 ("I960"): i-iv + 
1-148, pis. 1-19, (distributed March 17, 1961). 

Okutani, T. 1983. World Seashells of Rarity and Beauty. 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 107 



Kawamura Collection. National Science Museum, Tokyo, 
i-iii + 1-12, 48 pis. 

Pilsbry, H. A. and Olsson, A. A. 1954. Systems of the Voluti- 
dae. Bull. Amer. Paleont. 35(152):271-306, pis. 25-28. 

Quinn, J. F., Jr. 1981. A new genus of Turbinellidae (Gastro- 
poda: Prosobranchia), with the description of a new 
species from the Caribbean Sea. The Nautilus 95(2):72-77, 
5 figs. 

Rehder, H. A. 1967. A new genus and two new species in the 
families Volutidae and Turbinellidae (Mollusca: Gastro- 
poda) from the western Pacific. Pacific Sci. 21(2):182-187, 
1 1 figs. 

1972. Some notes on the genus Teramaehia 



(Volutidae: Calliotectinae). The Veliger 15(1):7-10, 7 figs. 

Shikama, T. 1963. Selected Shells of the World Illustrated in 
Color. Tokyo, pp. 1-154, pis. 1-102, 211 text figs. 

Slack-Smith, S. 1980. New records for the western Austra- 
lian continental slope. Australian Shell Netvs. Malac. Soc. 
Australia, no. 32, pp. 1, 2, illus. 

Weaver. C. S. and duPont, J. E. 1970. Living volutes: a 
monograph of Recent Volutidae of the world. Delaware 
Mus. Nat. Hist. Mong. Ser., No. 1, xv + 374 pp., 79 col. 
pis., 44 figs., 13 maps. 

Wells, F. 1983. Wonders from the Northwest. Australian 
Shell News, Malac. Soc. Australia, no. 43, pp. 4, 5, illus. 



ADDITIONAL COLORADO RECORDS OF ANODONTA GRANDIS 
GRANDIS SAY (BIVALVIA: UNIONIDAE) 



Scott J. Herrmann and James R. Fajt 

Department of Life Sciences 

University of Southern Colorado 

Pueblo, CO 81001 



Upon first finding Anodonta grandis grandis 
Say, 1829, in large numbers in the Colorado 
Fuel and Iron Reservoirs No. 2 and No. 3 near 
Pueblo, Colorado, in August of 1982, we became 
concerned about the rarity of them elsewhere in 
the state. Since the summer of 1982 we have 
been searching eastern Colorado for viable 
populations of this freshwater mussel. 

All the water in C.F.&I. Reservoir No. 3 had 
to be released by February 1983 so a new water 
control valve could be installed in the dam 
before the spring runoff began. As the water 
level was lowered, thousands of Anodonta 
grandis grandis became exposed. In February 
1983 we transferred 412 adults from the 
C.F.&I. Reservoir No. 3 to the newly formed 
Pueblo Reservoir. Statewide news media cover- 
age of this transplanting operation brought 
many calls and messages regarding the occur- 
rence of bivalves elsewhere in eastern Colorado. 
Each of these notices was investigated. If dur- 
ing these investigations A. grandis grandis was 
found, we attempted to collect the largest (in 
length) and smallest specimens available. In 
addition, from each site at which A. grandis 
grandis was found a 1 liter composite (surface to 
near bottom) water sample was collected and 



kept on ice in a cooler until our return to the 
laboratory. In the Water Resources Laboratory 
of the University of Southern Colorado standard 
methods were used to analyze the cooled water 
samples. Atomic absorption spectrophotometric 
methods were used for the analysis of Na, K, 
Cu, Mn, Fe, and Zn. Sediment was examined in 
the field for relative particle size. 

Burch (1973) indicated the North American 
range for Anodonta grandis grandis as being 
throughout the Mississippi-Missouri River 
drainage. In Colorado Brandauer and Wu (1979) 
cite only two old records for this species: one 
from 1911 in Boulder County, 30 miles north of 
Denver, consisting of 1 specimen; and a second 
collected 10 October 1915 from Yuma County, a 
pool in Black Wolf Creek, IV2 miles north and 1 
mile west of Beecher Island, consisting of 35 
specimens. The large collection from Black Wolf 
Creek in far eastern Colorado was made by Ellis 
(1916), who reported they were abundant and 
tightly embedded in the dense blue clay bottom. 
On 21 October 1983 we visited the vicinity of 
Black Wolf Creek described by Ellis (1916) and 
Brandauer and Wu (1978) and attempted to col- 
lect living specimens. All we found after search- 
ing about a mile segment were four shell frag- 



108 THE NAUTILUS 



October 31, 1985 



Vol. 99(4) 



merits of this species. Without more specific in- 
formation it was impossible to locate the 
Boulder County site. It is quite possible that 
Anodonta grandis grandis is now extinct in the 
two sites reported by Brandauer and Wu (1978). 

Recently, Wu (1984) reported to us another 
locality where this species is surviving. The 30 
specimens and one valve (University of Colo- 
rado Museum [UCM] Collection No. 28913) erro- 
neously identified as Anodontoides ferussa- 
cianus (Lea) in Brandauer and Wu (1978) p. 48, 
from Boyd Lake, Larimer County are in fact 
Anodonta grandis grand is. An additional collec- 
tion (UCM No. 32168) from Boyd Lake of two 
specimens and six valves are also A. grandis 
grandis. 

Four lentic sites were found to support thriv- 
ing populations. Two of these sites, C.F.&I. 
Reservoir No. 2 and No. 3, are new drainage 
records for Colorado. To date Anodonta grandis 
grandis has not been reported from the Arkan- 
sas River drainage in Colorado. These two 
records probably represent the extreme west- 
ward extension of the range of this species 
because only ten miles (16 km) west the Great 
Plains give way to the foothills of the Wet Moun- 
tain frontal range. The other two sites, Mayham 
Lake and Flagler Reservoir, are located in the 
South Platte and Republican River drainages 
respectively. The specific geographical and 



altitudinal data for each of these four sites are 
indicated in Table 1. All are on the Colorado 
Great Plains and occur at about the same eleva- 
tion. If in the past a site had a different name, or 
is today known by multiple names, all such 
names have been indicated in Table 1. 

The range in size (total length) for all living 
naiads examined from each site were as follows: 
Flagler Reservoir (85 to 186 mm for 42 speci- 
mens), Mayham Lake (30 to 160 mm for 80 
specimens), C.F.&I. Reservoir No. 2 (19 to 183 
mm for 121 specimens), and C.F.&I. Reservoir 
No. 3 (11 to 192 mm for 534 specimens). We 
have determined that in the latter two sites this 
species showed a continuous age structure from 
one to fifteen years. It appears to us that 
Anodonta grandis grandis is reproducing and 
thriving in all four sites. 

A comparison of the water quality for the four 
study sites in Table 2 shows all have hard water 
(171 to 233 mg/L CaC0 3 ) that is highly buffered. 
Trace metals (Fe, Cu, Zn, and Mn) in the dis- 
solved fraction are all relatively low (<0.2 mg/L) 
and do not appear to present any toxic prob- 
lems. Under these conditions Anodonta grandis 
grandis could be expected to have available suf- 
ficient calcium carbonate for shell construction. 
In addition, all the sediments contained varying 
mixtures of particles from clay to coarse sand. 
The occurrence of this species in a wide variety 



TABLE 1. Geographical and altitudinal data for new site records of Anodonta grandis grandis Say in Colorado. 



Name of reservoi r 


Elevation 
ft. a.s.l.* 
(m a.s.l . ) 


County 


Coordinates 


Local ity 


River drainage 














Flagler Res. 


4707 (1435) 


Kit Carson 


T9S, R50W, 
S5, 4, 9, 10 


34 mi (57 km) 
E. of Limon 


Republ ican 


Mayham Lake 
(Hidden Lake 
or Hud Lake) 


5281 (1610) 


Adams 


T3S, R68W, 
S6 


1 mi (1.6 km) 
S. of Westmin- 
ster (N.W. 
Denver) 


South Platte 


C.F.&I. Res. No. 2 
(St. Charles Res. 
No. 2) 


4913 (1497) 


Pueblo 


T21S, R65W, 
S34 & 35 


9 mi (14.5 km) 
S. of Pueblo 


Arkansas 


C.F.&I. Res. No. 3 
(St. Charles Res. 
No. 3) 


4960 (1512) 


Pueblo 


T21S, R65W, 
S33 & 34 
and T22, 
R65W, S3 & 
4 


9 mi (14.5 km) 
S. of Pueblo 


Arkansas 



*feet above sea level (meters above sea level) 



Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 109 



TABLE 2. Physico-chemical water quality data for four new site records of Anodonta grandis grandis Say in Colorado. 
All data reported as mg/L except dates, turbidity, pH, and conductivity, "is raw water determination, "not detectible 
(<0.01 mg/L). 













Parameter 


Flager Res. 


Mayham Lk. 


C.F.&I. Res. No. 2 


C.F.&I. Res. No. 3 


Date of water samplinq 


21 Oct. 83 


6 Sept. 83 


14 Feb. 84 


3 Mar. 84 


Turbidity* (JTU) 


38 


40 


15 


10 


Total Hdns. (CaC0 3 ) 


232 


171 


233 


179 


Ca Hdns. (CaC0 3 ) 


120 


105 


182 


121 


Mg. Hdns. (CaCCh) 


112 


56 


51 


58 


Ci 


72.5 


81.0 


11.5 


23.5 


so 4 


45 


41 


35 


28 


Na 


102 


117 


19 


16 


K 


13.6 


18.0 


3.0 


2.8 


Conductivity (jjS ) 


870 


890 


480 


370 


Fe 


ND** 


ND 


ND 


ND 


Cu 


.005 


.005 


.003 


.003 


Zn 


.012 


.006 


.014 


.014 


Mn 


.005 


.160 


.006 


.006 


T-alk* (CaC0 3 ) 


141 


118 


138 


131 


pH* 


8.2 


8.3 


7.3 


7.6 



of substrates was documented by Clarke and 
Berg (1959). 

All four reservoirs support a variety of com- 
mon warm-water fish: the green sunfish 
(Lepomis eyanellus), bluegill (Lepomis macro- 
chirus), pumpkinseed (Lepomis gibbosm), and 
carp (Cyprinus carpio). In addition, Flagler 
Reservoir supports a thriving population of 
largemouth bass (Micropterus salmmdes), and 
C.F.&I. Res. Nos. 2 and 3 channel catfish 
(Ictalurus pimetatus), white crappie (Pomoxis 
annularis), and black crappie (Pomoxis nigro- 
maculatus). Most of these fish are known hosts 
for the glochidia of Anodonta grandis grandis. 

Acknowledgments 

We are indebted to Dr. John B. Burch, Muse- 
um of Zoology and Department of Ecology and 
Evolutionary Biology, University of Michigan, 
for confirming our identifications of Anodonta 
grandis grandis. We are particularly grateful to 
Dr. Shi-Kuei Wu, University of Colorado 



Museum, for criticizing the first draft of this 
manuscript. We would also like to publicly thank 
Mr. Bob Paytin of the Colorado Division of 
Wildlife for assistance with field work. Funds to 
support this research were provided by the 
University of Southern Colorado Faculty 
Research Grant Program and the Colorado Divi- 
sion of Wildlife. 

LITERATURE CITED 

Brandauer, N. and S.-K. Wu. 1978. The Bivalvia of Colorado, 

Part 2. The Freshwater mussels (Family Unionidae). 

Natur. Hist. Invent. Colo.. 2:41-60. 
Burch, J. B. 1973. Freshwater unionacean clams (Mollusca: 

Pelecypoda) of North America. U.S. Environ. Protect. 

Aq. Biota of Freshwater Ecosystems Ident. Manual 

11:1-176. 
Clarke, A. H. and C. O. Berg. 1959. The freshwater mussels 

of central New York with an illustrated key to the species 

of northeastern North America. Cornell Univ. Mem- 

367:1-79. 
Ellis. M. M. 1916. Anodonta douielsi Lea in Colorado. The 

Nautilus 29:116-119. 
Wu, S.-K. 1984. Personal conimnniration. 31 May 1984. 



110 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



A 40-WEEK STUDY ON GROWTH OF THE ASIAN CLAM, 

CORBICULA FLUMINEA (MULLER), IN THE 

KANAWHA RIVER, WEST VIRGINIA 

James E. Joy 

Department of Biological Sciences 

Marshall University 

Huntington, WV 25701 

ABSTRACT 
A sample population of Corbicula fluminea individuals maintained in cages 
was monitored over a 40-week period (12 March to 16 December 1983) to assess 
growth (in shell length, and overall body weight), percentage of total body weight 
made up of soft tissues (i.e. "condition index"), and mortality rate. There were vir- 
tually no increases in length or weight when water temperatures were below 10°C. 
Noticeable growth began when water temperature reached ~ 14° C. Highest rates 
of growth (shell length, 0.66 mm/wk; weight, 0.26 gmlwk) occurred when water 
temperatures were between 2U° and 30° C. "Condition indices" (ranging from a 
low of 12.6% in June to a high of 21.2% in October) for experimentally caged clams 
were similar to those found in natural stream clams. Twenty-five of the 300 (8.3%) 
clams under experimental conditions died. 



In September 1980, operation of Unit 2 at 
Arkansas Power and Light's Nuclear One power 
plant near Russellville had to be shut down 
because of an extensive invasion of the reactor's 
emergency cooling system by Asian Clams, Cor- 
bicula fluminea (Miiller, 1776). The cleanup took 
29 days at a cost to AP&L of 15.3 million dollars 
(Griffin, 1983). After the AP&L case, the 
Nuclear Regulatory Commission found that 10 
other nuclear power plants had experienced bio- 
fouling problems because of C. fluminea. 
although not to the extent found in the 
Arkansas facility (Buel, 1983). 

The biofouling potential of this clam species 
prompted the NRC, and the Electric Power 
Research Institute of Palo Alto, California, to 
sponsor the Second International Corbicula 
Symposium at Little Rock, Arkansas (hosted by 
AP&L and the University of Arkansas) in June 
of 1983. During those meetings McMahon (1983, 
pers. comm.) stressed the need for more infor- 
mation regarding northeastern populations of 
C. fluminea. Although the present work had 
begun prior to the symposium, McMahon's com- 
ments provided an added incentive for the con- 
ii m of this project assessing the growth of 
C. fluminea in West Virginia over an extended 
time period. 



It should be added that C. fluminea, as an in- 
troduced species, has become widely dispersed 
throughout the major drainages of the United 
States, and that many types of industrial 
facilities are threatened by large accumulations 
of this nuisance species. For an account of the 
spread of this clam the reader is referred to 
McMahon (1982). 

Materials and Methods 

On 5 March 1983, 470 Corbicula fluminea in- 
dividuals, measuring 9.0 to 15.2 mm in shell 
length, were collected from Mud River, West 
Virginia (MG92885315, USGS Topographic 
Map, Milton Quadrangle, W. Va. 1972) and car- 
ried to the laboratory at Marshall University in 
two 20 liter containers. Twenty clams were 
selected at random, cleaned with absorbent 
nylon reinforced towels (Fisher Teri® Wipers), 
measured individually for shell length to the 
nearest 0.1 mm with vernier calipers, then 
weighed collectively for total weight. Soft 
tissues were removed from these clams, blotted 
dry on another absorbent towel, then weighed. 
A baseline "condition index" (C. I.) was deter- 
mined by: 



c I 



wet soft tissue weight 
total weight 



. mil 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 111 



Both weighings were made on a Mettler Model 
P1000 balance to the nearest 0.01 gm. The re- 
maining 450 clams were transferred to an 
unheated building where they were maintained 
at water temperatures of 10° to 14°C in a 50 
gallon aerated aquarium containing a substrate 
of sand and gravel to a depth of 8.0 cm. 

On 12 March 1983 (Day Zero), clams were 
transported to the field site at the U. S. Army 
Corps of Engineers Marmet Locks and Dam on 
the Kanawha River, West Virginia (milepoint 
67.7, Kanawha River Navagation Charts, Corps 
of Engineers, Jan. 1975). Clams were selected 
randomly and segregated into 15 groups on site. 
The 30 clams in each group were cleaned then 
measured individually for shell length as 
described previously. Clams in each group were 
then weighed collectively on an Ohaus triple- 
beam balance for total weight to the nearest 0.1 
gm. Mean lengths and weights were recorded 
for Day Zero. 

A series of 15 cages, in three floating units (cf. 
Fig. 1), were used to hold clams. Each group of 
30 clams was placed in a separate cage, along 
with a sand and gravel substrate approximately 
6.0 cm deep. Each unit of five cages was then 
lowered into the river and secured to the outer 
lock wall (away from barge traffic) with an ap- 
propriate length (~ 3 meters) of 3/8 inch dia- 
meter nylon rope. Surface water temperature 
was recorded for Day Zero, and on each collec- 
tion date (Table 1; Fig. 2A) thereafter. 



After two weeks the floating unit with Cage 
#1 was pulled from the river and all living clams 
retrieved from that cage. These clams were 
cleaned and divided into two equivalent length 
subgroups. Mean lengths and weights were 
determined for each subgroup. One subgroup 
(open triangles of Fig. 2B) was returned to the 
laboratory for a C. I. determination. Clams of 
the second subgroup (open squares of Fig. 2B) 
were replaced in the cage and lowered back into 
the river. After an additional two weeks at 
prevailing temperatures, clams in the second 
subgroup of Cage #1 were retrieved, cleaned, 
and measured again for length and weight then 
returned to the lab for a C. I. determination. 

The procedure for handling clams in subse- 
quent weeks (collection schedule, Table 1) for 
Cages #2 thru #10 was the same as described for 
Cage #1. Clams collected on those dates in nor- 
mal type of Table 1 (symbolized as closed circles 
in Fig. 2B and diagonal line bars in Fig. 2C) 
yielded data pertaining to increases in length, 
and weight, from Day Zero. Thus as the experi- 
mental time period increased, measured growth 
took place over widely varying temperature con- 
ditions (Fig. 2A). Clams retrieved on those dates 
in boldface type of Table 1 (symbolized as closed 
squares in Fig. 2B and dark bars of Fig. 2C) 
yielded data on length, and weight, increases 
over a two week period only, at relatively con- 
stant temperature ranges. This procedure also 
permitted a C. I. determination every two 



rope hole 



styrofoam 
floatation 
collar 



upper 
and lower 
bars hold 
collar 




aluminum screen 

along both sides of 

unit 

side wall 
to retain 
substrate 

FIG. 1. Line drawing (not to scale) of field unit with five cages. 



112 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



MIAN W T. gin 



SHELL LENGTH mn 
— — si s> 

O ui o 






% 



V 



% 



b 1 

V 



< 



b 1 



V 



b 1 

p 



* 



{ 



h'.WWiM c 



Ffnifinin 



I 



■WWWW1-' £ 



II I I I IIIIIITfffl 
LI I 1 1 1 1 III I 1 1 1 1 1 



Lwwwww. 



kWWWWW i, 



iiiiii v rrvrrmvm . 
| ' 

lo 



_l^_ 



TEMP C 



o 

1 I I 





•— 0-« * 2j 



_1»>J 



!■■■ 



FIG. 2A. Surface water temperatures recorded within cage 
: fit' collection. 

FIG. 2B. Opel] circles = mean SL (shell length) on Day 
Zero. Closed circles = mean SL after experimental period 
(in weeksi designated on X-axis. Open triangles = mean SL 
of lab subgroup, open squares = mean SL of field subgroup. 
I squares = mean SLof field subgroup after additional 
two week period in field. Vertical lines = SL range. 
Numbers a ■ in symbols - mean SL increase for 



period indicated along X-axis. Numbers below vertical lines 
= sample size of living clams. 

FIG. 2C. Open bars = mean weight on Day Zero. Diagonal 
line bars = mean weight after experimental period. Stippled 
bars = mean weight of field subgroup. Dark bars = mean 
weight of field subgroup after additional two week period in 
field. Numbers above diagonal line bars = mean weight 
increase during experimental period (since Day Zero) in- 
dicated along X-axis. Numbers above dark bars = mean 
weight increase for field subgroup during two week period. 
Sample sizes same as in Fig. 2B. Weights of lab subgroup 
not shown. 



weeks. Condition indices of on-site caged clams 
were compared with those determined for clams 
collected from natural stream conditions at the 
original collection site (Table 2). 

Results 

Growth of C. fluminea, as determined by in- 
creases in shell length, and overall weight, over 
a 40-week period is shown in Fig. 2 B & C. There 
was virtually no growth in those clams main- 
tained in Cages #1 and #2 when water tempera- 
tures were <10°C. Cessation of growth for large 
clams at <10°C was also recorded for Cages #9 
and #10. Noticeable growth was first observed 
for those clams in Cage #3 when water tempera- 
tures were ~14°C and rising. Although only 
negligible growth occurred during the first eight 
weeks, clams doubled in weight after approxi- 
mately 15 weeks, but did not double in shell 
length until the 34th week. 

Rates of increases in shell length and total 
weight were calculated at two week intervals to 
minimize the effect temperature fluctuations 
have on growth of C. fluminea. On that basis, 
greatest rate increases in shell length (ranging 
from 0.48 mm/wk to 0.66 mm/wk) were re- 
corded for those clams maintained in Cages #4 
thru #7 when water temperatures were between 
24° and 30°C. Greatest rate increases in weight 
(ranging from 0.18 gm/wk to 0.26 gm/wk) also 
occurred in Cages #4 thru #7. 

"Condition," defined as percentage of total 
weight made up by soft tissue, of experimental 
caged clams was comparable to that of natural 
stream clams (Table 2). 

Twenty-five of the 300 (8.3%) clams in Cages 
#1 thru #10 died throughout the course of the 
study (Fig. 2B). 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 113 



TABLE 1. Collection schedule* for C. fluminea in the Kanawha River, Marmet Dam, W. Va. 



Cage #1 



»2 



* 1 



14 



#5 



«i, 



#7 



#8 



#9 



#10 



DAY ZERO 12 Mar 12 Mar 12 Mar 12 Mar 12 Mar 12 Mar 12 Mar 12 Mar 12 Mar 12 Mar 
2 weeks 26 Mar 



4 
'i 
8 
10 
12 
14 
16 
18 
20 
22 
24 
.:>■ 
28 
30 
32 
u 
36 

<K 

40 



9 Apr 



23 Apr 
7 May 



21 May 
5 Jun 



18 Jun 
2 Jul 



16 Jul 
30 Jul 



12 Aug 
26 Aug 



9 Sep 
23 Sep 



7 Oct 
2!Oci 



4 Nov 
18 Nov 



2 Dec 
16 Dec 



*Cages 11 thru 15 were invaded by a predator [muskrat (s) ?] sometime between 2 and 6 
December 1983. Number of survivors in these cages was too small to continue experiment 
beyond 16 December 198 3. 



Discussion 

Growth-Shell Length: 

That growth of Corbicula fluminea did not 
occur at temperatures of <10°C corroborates 
the findings of previous investigators. For ex- 
ample, Eng (1977), working with C. fluminea in 
California, noted that, "Growth ... is negligible . 
. . when water temperature is below about 
14°C." And, in the first two weeks of Welch and 
Joy's (1984) "cold water" experiment, when tem- 
peratures were falling from 19° to 13.5°C, 
clams in their two smallest designated shell 
length classes grew at a rate of 0.5 mm/wk. 
However, for the next 10 weeks of that experi- 
ment, when water temperatures ranged be- 
tween 13.5° and 0.5°C, there were no increases 
in mean shell lengths. 

Conversely, optimum growth for C. fluminea 
occurs ". . . in the mid-twenty °C range" 
(Mattice and Dye, 1979). That same general 
observation had been made earlier by Heinsohn 
(1958), and O'Kane (1976) for C. fluminea in 
California and Texas, respectively. More recent- 



ly, Scott-Wasilk, et al, (1983) reported shell 
length increases of ~ 0.80 mm/wk for C. 
fluminea from June thru September in northern 
Ohio. Welch and Joy (1984) recorded mean shell 
length increases, uder optimum summertime 
conditions (21.5°-31.0°C), of 0.79, 0.86, and 0.95 
mm/wk (over 12 weeks) for C. fluminea with in- 
itial (Day Zero) mean lengths of 13.0, 10.8, and 
8.7 mm, respectively. They added that those 
rates compared favorably with growth rates for 
C. fluminea individuals (with similar initial shell 
lengths) in the west and southwest. Thus max- 
imum increases in mean shell lengths of 0.48 to 
0.66 mm/wk recorded for C. fluminea in- 
dividuals maintained under optimum summer- 
time conditions in Cages #4 thru #7 (Fig. 2 A & 
B) were anticipated. That these rates were 
somewhat less than recorded by Welch and Joy 
was not disturbing because clams in the present 
study had higher initial mean shell lengths (15.2 
mm, open square of Cage #4 to 22.5 mm, open 
square of Cage #7; Fig. 2B). Since rate of shell 
length increase in C. fluminea is an inverse 



114 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



TABLE 2. A comparison of condition indices between clams under experimental caged 
conditions (at Marmet), and similarly-sized clams under natural field conditions at the 
original collection site (Mud River Falls). 







Marmet 






Mud River Falls 




Date 




SL range (nm) 


C.I. 




SL range (mm) 


C.I. 


1983 


N = 


of sample 


(%) 


N = 


of sample 


(%) 


5 Mar 








20 


9.5-14.1 


14.7 


26 Mar 


15 


9.7-14.3 


13.5 








6 Apr 








25 


8.5-14.8 


15.0 


9 Apr 


l-i 


9.3-14.5 


14.3 








23 Apr 


14 


9.4-14.2 


13.6 








7 Mav 


15 


8.8-15.3 


14.1 








21 Mav 


15 


12.0-15.3 


14.0 








29 May 








18 


12.2-14.7 


12.8 


5 Jun 


14 


12.5-15.8 


12.7 








16 Jun 








19 


12.7-16.7 


12.6 


18 Jun 


15 


12.6-17.1 


12.6 








2 Jul 


15 


14.3-17.8 


17.6 








16 Jul 


14 


16.3-18.9 


18.2 


13 


15.5-19.5 


16.0 


30 Jul 


12 


17.5-20.3 


17.0 








10 Aug 








8 


19.0-23.0 


19.3 


13 Aug 


14 


19.7-22.1 


18.1 








26 Aug 


13 


20.3-23.1 


18.3 








9 Sep 


15 


22.2-23.8 


17.3 








14 Sep 








9 


21.2-24.6 


18.1 


23 Sep 


15 


21.8-24.6 


19.3 








7 Oct 


15 


22.3-26.1 


21.2 








18 Oct 








10 


20.6-24.5 


20.3 


21 Oct 


15 


22.6-26.8 


20.1 








4 Nov 


14 


24.7-26.9 


19.2 








18 Nov 


15 


24.9-26.5 


18.1 








2 Dec 


8 


24.8-27.5 


18.3 








16 Dec 


7 


24.8-27.5 


18.9 









No collections beyond 18 Oct because of high water. 



linear function (Mattice and Dye, 1979; Joy, in 
Press) rate differences between Welch and Joy's 
work and the present study are more likely the 
reflection of initial mean shell lengths rather 
than any intrinsic difference in growth patterns 
for clams in the two studies. 

Growth-Weight: 

As noted by Welch and Joy (1984), "Increases 
in weight have largely been ignored ... as a 
measure of growth in C. fluminea." Those 
writers reported mean weight gains of 0.27 to 
0.30 gm/wk (over 10 weeks) for "warm water" 
(21.5° to 31.0°C) classes of C. fluminea in- 
dividuals with initial mean weights of 0.53 gm 
and 1.20 gm for the smallest and largest classes, 
respectively. Although not an ideal comparison 
because of differences in initial mean weights, 
clams in Cages #5, #6, and #7 (with initial mean 
weights of 2.2, 3.5, and 4.2 gm, respectively) ex- 
hibited similar weight gains under comparable 
temperature conditions (calculated over two 
week periods; solid bars of Fig. 2C). O'Kane 



(1976) reported weight gains of 0.18 gm/wk for 
clams with an initial weight of 3.15 gm; some- 
what less than the rate of 0.25 gm/wk recorded 
for similarly-sized clams in Cage #6. 

Weight gains noticeably lower than those 
found in the present study were recorded by Joy 
(In Press) who calculated an increase of only 
0.13 gm/wk (over nine weeks) for clams with an 
initial mean weight of 2.6 gm. And Hartley 
(1981), working with C. manilensis ( = C. 
fluminea) as a potential biological monitor for 
pesticides in Illinois, cited mean weight gains of 
0.055 gm/wk (after 18 days) and 0.007 gm/wk 
(after 72 days). However, Hartley used relative- 
ly large clams (5.3 gm) maintained in much 
lower temperatures. 

( 'audition [mlices: 

There is the question, when dealing with 
"caged" clams, regarding possible limiting ef- 
fects brought about by artificially confining the 
test animals. McMahon and Williams (In Press) 
were convinced that ('. tluminea individuals in 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 115 



cages grew as well as their in-stream counter- 
parts. Since it is impractical to monitor growth 
of marked individuals in natural populations for 
any length of time, another measure of deter- 
mining the health or "condition" of caged in- 
dividuals, relative to those in natural stream 
conditions, was sought. The soft tissue weight 
as a percentage of total weight (i.e. "condition 
index") determined every two weeks for caged 
individuals compared favorable with similarly- 
sized in-stream clams (Table 2). Both groups 
(caged and natural populations) exhibited 
similar C. I. patterns, with low C. I.'s occurring 
in May and June, and relatively high C. I.'s from 
mid-August to the end of the study period. Thus 
the argument that "caged" clams suffered no ill- 
effects by their confinement can be made with 
some conviction (and confirms McMahon and 
Williams' view). 

There is no ready explanation for the low C. 
I.'s during May and June. However, it could 
have been indicative of an energy drain on clams 
preparing for spawning. Nearly all clams were 
gravid in the July samples, a phenomenon con- 
sistent with the findings of Bickel (1966) who 
reported a July spawning for C. fluminea in the 
Ohio River near Paducah, Kentucky. Still, what 
controls spawning in C. fluminea is poorly 
understood. Periods of ova and sperm produc- 
tion, and spawning, are presently being in- 
vestigated in this lab. 

Mortalities: 

Twenty-five of 300 (8.3%) clams died through- 
out the 40 week experimental period (Fig. 2B). 
That did not include those clams originally 
placed in Cages #11 thru #15, which were ap- 
parently destroyed by a predator (Table 1). This 
mortality rate does not seem unduly high when 
compared to previous investigations. O'Kane 
(1976) lost only 6.0% of his original 340 clams 
over a 12 month period. Hartley (1981) recorded 
a low mortality (4 of 660 clams) over 72 days, 
and Joy (In Press) reported only seven clam 
deaths from a sample population of 600 over a 
nine week period. Welch and Joy (1984) re- 
corded a relatively high mortality rate of 27.5% 
(22 of 80 clams) for clams maintained at the 
same river location (under temperature condi- 
tions similar to the present study) during the 
previous summer. They also reported a mortali- 



ty of 19.0% for clams monitored during cold 
water temperatures. And finally, Buttner (1981) 
recorded high mortality rates (64%, 44% and 
21% for the summers of '77, '78, and '79, respec- 
tively) for C. fluminea maintained in cages in 
catfish rearing ponds. Those ponds were sub- 
jected to Karmex, Batex, and rotenone treat- 
ments which may have accounted for the high 
mortality levels. 

While a considerable body of literature on 
growth of C. fluminea in different geographical 
locales has accumulated since Villadolid and Del 
Rosario's publication of 1930 on juvenile clams, 
comparisons of growth rates are not easily 
made. Investigators have utilized clams of dif- 
ferent initial sizes under diverse temperature 
conditions for widely varying study periods. The 
complexity of the problem is compounded by a 
lack of information on nutritional requirements 
of the Asiatic clam. Knight (1983) has achieved 
some success - with considerable effort - in iden- 
tifying several algal species as potential food 
sources. Avenues of research regarding growth 
and feeding of C. fluminea have not been ex- 
hausted. Indeed, there is much work yet to do. 

Acknowledgments 

I want to thank Mr. Kenneth Welch for his in- 
valuable assistance throughout the course of 
this study. 

LITERATURE CITED 

Bickel, D. 1966. Ecology of Corbicula manilensis Philippi in 
the Ohio River at Louisville, Kentucky. Sterkiana 
23:19-24. 

Buel, S. 1983. Clam symposium comes as triumph for 
zoologist. Arkansas Democrat, 24 June, (not seen; fide 
Corbicula Newsletter, Nov. 1983, p. 5). 

Buttner, J. K. 1981. Asiatic clam in channel catfish rearing 
ponds: Its biology and its effect on water quality. Doctoral 
Dissertation. Southern Illinois Univ., Carbondale, Illinois. 
253 pp. 

Eng, L. L. 1977. Population dynamics of the Asiatic clam 
Corbicula fluminea (Muller), in the concrete-lined Delta- 
Mendota Canal of central California. Proc. First Int'l. 
Corbicula Symp., Fort Worth, Texas, 13-15 October. 

Griffin, J. M. 1983. Meeting Prospectus and Welcome. 
Second Int'l. Corbicula Sump.. Little Rock, Arkansas, 
21-24 June. 

Hartley, D. M. 1981. The use of the freshwater clam Cor- 
bicula manilensis as an in situ monitor of freshwater 
quality. M. S. Thesis, University of Illinois, Urbana, 
Illinois. 104 pp. 

Heinsohn, G. E. 1958. Life history and ecology of the fresh- 
water clam, Corbicula fluminea. M. A. Thesis, Univ. 



116 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



California, Berkeley. 64 pp. 

Joy, J. E. In press. Growth rate of Corbictda jluminea at 
four sites on the Kanawha River, W. Va. Second Intl. Cor- 
bicula Symp.. Little Rock, Arkansas, 21-24 June. 

Knight, A. 1983. (Pers. Comm.) Second Intl. Corbicula 
Symp.. Little Rock, Arkansas, 21-24 June. 

McMahon. R. F. 1983. (Pers. Comm.) Second Intl. Corbicula 
Symp., Little Rock, Arkansas, 21-24 June. 

McMahon, R. F. and Williams, C. J. In press. A reassess- 
ment of growth rate, life-span, and life-cycle in a natural 
population and caged individuals of Corbicula Jluminea. 
Second Intl. Corbicula Symp., Little Rock, Arkansas, 
21-24 June. 

Mattice, J. S. and Dye, L. L. 1979. Growth of the Asiatic 
clam. N. Amer. Benthol. Soc, 27th Annual Meeting, Erie, 
Pennsylvania, 18-20 April. 



O'Kane, K. D. 1976. A population study of the exotic bivalve 
Corbicula manilensis (Philippi, 1841) in selected Texas 
reservoirs. M. S. Thesis, Texas Christian University, Fort 
Worth, Texas. 

Scott- Wasilk, J., Lietzow, J. S., Downing, G. G. and Clayton, 
K. L. 1983. Growth of Corbicula Jluminea in Lake Erie. 
N. Amer. Benthol. Soc. 31st Annual Meeting, LaCrosse, 
Wise, 27-29 April. 

Welch, K. J. and Joy, J. E. 1984. Growth rates of the Asiatic 
clam, Corbicula Jluminea (Miiller), in the Kanawha River, 
West Virginia. Freshwater Invertebr. Biol. 3:139-142. 

Villadolid, D. V. and del Rosario, F. G. 1930. Some studies 
on the biology of the Tulla (Corbicula manilensis Philippi), 
a common food clam of Laguna de Bay and its tributaries. 
Philippine Agriculturist 19:335-382. 



FRESHWATER MUSSELS (UNIONIDAE) 
OF THE BIG BLACK RIVER, MISSISSIPPI 

Paul D. Hartfield and Richard G. Rummel 

Mississippi Museum of Natural Science 

111 North Jefferson Street 

Jackson, MS 39202 



ABSTRACT 

Collections of freshwater mussels made in 1980-81 along 321 km of the Big Black 
River of Mississippi produced 31 species of unionids and the Asian Clam (Cor- 
bicula fluminea (Miiller, 1774)). This study is compared with a 1904 and 1969 
survey of the unionid fauna of this river system. 



Prior to this study, the only major records of 
freshwater mussels from the Big Black River in 
Mississippi were by Hinkley (1906) and 
Grantham (1969). Hinkley recorded 18 species 
collected in 1904 near Durant, Holmes County. 
Grantham included the Big Black River in a 
statewide survey of the pelecypod fauna, but 
added no species new to the river, and con- 
firmed only seven of those reported by Hinkley. 

The objectives of this study were to determine 
the species composition of unionids in the Big 
Black River and to compare the present fauna 
with the findings of earlier workers. 

Methods 

During the summers of 1980 and 1981, we 
surveyed about 321 km of the Big Black River 
from the mouth at the Mississippi River up- 
stream to Mississippi Highway 407, Mont- 



gomery County. Sand and gravel bars were 
searched for dead shells and riffles and shallow 
reaches were sampled by hand for live mussels. 
Voucher specimens of uncertain identifications 
were confirmed by the Ohio State University 
Museum of Zoology. The collections are 
deposited in the Bivalve Collection of the 
Mississippi Museum of Natural Science, 
Jackson, Mississippi. 

Study Area and Habitats 

The Big Black River originates in the North 
Central Hills of central Mississippi and flows 
southwestwardly for about 434 km before enter- 
ing the Mississippi River 40 km below Vicksburg 
(Fig. 1). 

The Big Black River Basin is long (248 km) 
and narrow (35 km) and crosses four physio- 
graphic divisions of the Coastal Plains Province 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 117 




FIG. 1. Big Black River, Mississippi. 

(USDA, 1968): the North Central Hills, Jackson 
Prairies, Loess Hills, and Mississippi Alluvial 
Plains (Fig. 2). Landform varies from broad, 
sand-hill uplands dissected by numerous 
streams in the upper basin to steep uplands 
dissected by relatively deep gorges in the lower 
basin. About 57% of the basin is forested, the re- 
mainder is composed of cropland and pasture. 

The main stem of the Big Black is a stream in 
good condition with relatively little pollution ex- 
cept for turbidity caused by agricultural runoff. 
Water quality of tributary streams is near ex- 
cellent except for some impairment at a few 
point sources of pollution. 

Perhaps the most striking feature of this river 
is the change in channel characteristics (depth, 
current, substratum) as it flows through the dif- 
ferent physiographic divisions. The lower part 
of the river in the Alluvial Plain is wide, deep 
and bayou-like with muddy waters, silt and mud 
bottom, and little current. 

In the Loess Hills above Mississippi Highway 
61, the banks are steep, muddy and unstable. 
There is much silt and mud substratum; how- 
ever the river often cuts through the loess to 
underlying deposits of gravel, and occasional 
gravel bars are encountered. Currents keep the 
gravel bars and riffles relatively free of silt. 




FIG. 2. Physiographic Regions of Mississippi. 

The river is shallow and meandering with 
numerous sandbars and predominantly sand 
bottom in the Jackson Prairies and the North 
Central Hills. Gravel substratum are rare to 
absent. 

Upriver from Vaiden, Mississippi, the river 
runs through a large bottomland swamp. Banks 
are low, heavily vegetated and the stream is 
narrow and deep with little current. Above this, 
about 40 km of the main channel has been 
channelized. 

Results and Discussion 

We collected 31 species of unionids and the 
Asian Clam (Corbicula jluminea) from the Big 
Black River (Table 1). Three of these (Quadrula 
nodulata (Rafinesque, 1820), Q. cylindrica 
cylindrica (Say, 1817), Pleurobema rubrum 
(Rafinesque, 1820)) were collected for the first 



118 THE NAUTILUS 



October 31, 1985 



Vol. 99(4) 



TABLE 1. Mussels collected from the Big Black River. 
h*MS (1980) 



Hinkley (1906) 



Grantham (1969) 



1. Anodonta imbecillis Say, 1829 

2. A. grandis grand is Say, 1829 

3. A. grandis corpulenta Cooper, 1834 

4. Arcidens confragosus (Say, 1829 

5. Megalonaias nervosa (Rafinesque, 1820) 

6. Plectomsrus dombeyanus (Valenciennes, 1827) 

7. Tritogonia verrucosa (Rafinesque, 1820) 

8. Quadrula apiculata aspera (Lea, 1831) 

9. Q. pustulosa pustulosa (Lea, 1831) 

10. Q. nodulata (Rafinesque, 1820) 

11. Q. cylindrica (Say, 1817) 

12. Amblema plicata perplicata (Conrad, 1841) 

13. Fusconaia ebena (Lea, 1831) 

14. F. flava (Rafinesque, 1820) 
*15. F. cerina (Conrad, 1838) 
*16. Pleurobema curtum (Lea, 1859) 

17. Pleurobema rubrum (Rafinesque, 1820) 

18. F.1 1 iptio crassidens crassidens (Lanark, 1819) 

19. Unicmerus tetralasmus (Say, 1830) 

20. Obliquaria reflexa (Rafinesque, 1820) 

21. Glebula rotundata (Lamark, 1819) 

22. Plagiola lineolata (Rafinesque, 1820) 

23. Obovaria jacksoniana Frierson, 1912 
*24. O. unicolor (Lea, 1845) 

25. O. subrotunda (Rafinesque, 1820) 

26. Truncilla truncata Rafinesque, 1820 

27. T. donaciformis (Lea, 1845) 

28. Leptodea fragilis (Rafinesque, 1820) 

29. Potamilus purpuratus (Lamark, 1819) 

30. Villosa lienosa (Conrad, 1834) 

31. Ligumia subrostrata (Say, 1831) 

32. Lampsilis teres anodontoides (Lea, 1831) 
*33. L. radiata hydiana (Lea, 1838) 

34. L. radiata luteola (Lamark, 1819 

35. L. ovata ventricosa (Barnes, 1823) 
*36. L. ornata (Conrad, 1835) 

37. Corbicula fiuminea (Muller, 1774) 

* Not collected by authors. 



Arcidens confragosus Say 



Tritogonia tuberculata Barnes 
Quadrula aspera Lea 
Quadrula pustulosa Lea 



Quadrula perplicata Conrad 

Quadrula hebetata Conrad 
Quadrula rubida Lea 
Pleurobema curta Lea 



Obovaria castanea Lea 
Obovaria unicolor Lea 



Plagiola donaciformis Lea 
Lampsilis gracilis Barnes 
Lampsilis purpuratus Lamark 
Lampsilis lineosus Conrad 

Lampsilis fallacies us Smith 
Lampsilis hydianus Lea 



Lampsilis excavatus Lea 



Tritogonia verrucosa 
Quadrula refulgens 

Amblema costata 



Obovaria unicolor 



Leptodea fragilis 
Proptera purpurata 



Lampsilis anodontoides 



Corbicula leana 



time in the eastern drainage of the Mississippi 
River south of the Tennessee River. 

Five of the species collected by Hinkley were 
not found during this survey (Table 1). With the 
exception of Johnson's record of a disjunct 
population of Lampsilis excavata (Lea, 1857) in 
the Black River system of Arkansas (Johnson, 
1980), Hinkley's report of L. ornata (Conrad, 
1835), Pleurobema curium (Lea, 1859), and 
Ohoraria unicolor (Lea, 1845) constitutes the 
only record of these species in the Mississippi 
River drainages. Otherwise, P. curium is 
endemic to the Tombigbee drainage (Stansbery, 
1976), while 0. unicolor and L. ornata inhabit 
streams flowing into the Gulf of Mexico from 
Alabama to the Amite River in eastern Louisi- 
ana (Stern, 1976, Burch, 1975). Lampsilis 
radiata hydiana (Lea, 1838) has been collected 
in both the Mississippi River drainage and the 
Gulf Coast drainage. These species may once 
have existed in the Big Black, and may yet, how- 



ever the presence and relative abundance of 
closely related or similarly appearing species (0. 
jacksoniana (Frierson, 1912), 0. subrotunda 
(Rafinesque, 1820), L. ovata ventricosa (Barnes, 
1823), L. radiata luteola (Lamark, 1819)) in the 
system suggests that the specimens may have 
been misidentified or mislabeled. Unfortunately 
we have been unable to locate and examine 
Hinkley's Big Black collections. 

The fifth species Fusconaia cerina (Conrad, 
1838) is virtually indistinguishable from F. flava 
(Rafinesque, 1820). Frierson (1927) believed 
there was no morphological evidence to sepa- 
rate these two species and considered F. cerina 
as a synonym of F. flava. Johnson (1980) also 
considers them to be ecophenotypes. Both forms 
are encountered in Mississippi with the F. flava. 
form occurring in Mississippi River drainages 
and the F. cerina form in Gulf Coast streams 
east of the Mississippi River. The only morpho- 
logical differences we have observed between 



Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 119 



the animals of these drainages has been nacre 
color. The form in the Big Black River that we 
consider to be F. flava has nacre that is com- 
monly white, with occasional individuals having 
a faint cream or orange-tinted nacre. This can 
be contrasted with the form F. cerina occurring 
in the Pearl, Pascagoula and Tombigbee drain- 
ages where bright red or pink nacre is common- 
ly encountered with only occasional individuals 
having white nacre. Other features of shell 
anatomy are highly variable and are not useful 
in separating these two forms. 

Grantham's 1969 monograph of Mississippi 
pelecypods reported seven species occurring in 
the Big Black and added Corbicula fluminea to 
the drainage list (Table 1). One of his records 
was a western range extension for the Gulf 
Coast species Quadrula refulgens (Lea, 1868). 
Johnson (1980) considers this species a synonym 
of Q. pustulosa (Lea, 1831). We do not concur, 
finding that these species differ in shell shape, 
nacre color, periostracum color, inflation, umbo 
height, and size and arrangement of pustules. 
Upon examination of the late Dr. Grantham's 
collections we found that he misidentified Q. 
pustulosa as Quadrula refulgens. Dr. Grantham 
consistently used Gulf Coast nomenclature for 
certain species in the Mississippi drainage, for 
example, Q. refulgens for Q. pustulosa, and 
Lampsilis straminea (Conrad) for L. radiata 
luteola. Grantham also reported Obovaria 
unicolor from the Big Black. It is likely that this 
was a similar misuse of nomenclature for 0. 
subrotunda; however, we were unable to find 
specimens from this river system among his col- 
lections. Since Grantham concentrated his ef- 
forts in east and south Mississippi, the absence 
of many other species from his account of the 
lower Mississippi River drainages appears to 
reflect collecting effort in that part of the state. 

One of the more interesting aspects of this 
survey was the change in substratum as the 
river flows through the different physiographic 
regions and the corresponding change in the 
makeup of the naiad fauna. The richest section 
of the river in terms of unionid diversity is in the 
Loess Hills physiographic region, roughly that 
stretch of river flowing between Highway 61 
and Highway 49. Eight species of mussels were 



collected only in this general area {Quadrula 
nodulata, Quadrula cylindrical. Pleurobema 
rubrum, Obliquaria reflexa Rafinesque, 1820, 
Fusconaia ebeua (Lea, 1831), Truncilla truncata 
Rafinesque, 1820, Arcidens confragosus (Say, 
1829), and Ellipsaria lineolata (Rafinesque, 
1920). Most were associated with gravel riffles 
and runs. 

Obovaria subrotunda, 0. jacksoniana, Lamp- 
silis radiata luteola and Glebula rotundata 
(Lamark, 1819) were collected only in shallow 
tributaries or the main channel flowing through 
the Jackson Prairies and North Central Hills. 
Uniomerus tetralasmus (Say, 1831), Anodonta 
grandis grandis Say, 1829), A. G. corpulenta 
Cooper, 1834, Anodonta imbecillis Say, 1829, 
and Ligumia subrostrata (Say, 1831) were col- 
lected from oxbows or found dead below oxbows 
draining into the river. 

Acknowledgments 

We would like to express appreciation to Dr. 
David Stansbery of the Ohio State University 
Museum of Zoology for his generous assistance 
in confirmation of identification and his usual 
helpful comments and suggestions. 

LITERATURE CITED 

Bureh, J. B. 1975. Freshirnter Unionacean Clams (Mollusca: 

Pelecypoda) of North America. EPA Proj #18050ELD, 

USGPO, Washington, D.C. 
Grantham, B. J. 1969. The freshwater pelecypod fauna of 

Mississippi. Ph.D. Dissertation Univ. S. Miss., Hatties- 

burg. 243 p. 
Frierson, L. S. 1927. A classified and annotated checklist of 

the North American naiades. Baylor Univ. Press, Waco, 

Texas, pp. 1-111. 
Hinkley. A. A. 1906. Some shells from Mississippi and 

Alabama. The Nautilus 20:52-55. 
Johnson, R. I. 1980. Zoogeography of North American 

Unionacea (Mollusca: Bivalvia) north of the maximum 

pleistocene glaciation. Bull. Mus. Comp. Zool. 149:2. 
Stansbery, D. H. 1976. Endangered and threatened plants 

and animals of Alabama. Bull. Ala. Mus. of Nat. Hist.. 

No. 2 Univ., AL. 
Stern, E. M. 1976. The freshwater mussels (Unionidae) of 

the Lake Maurepas-Ponchartrain-Borgne drainage 

system, Louisiana and Mississippi. Dissertation La. St. 

Univ., Baton Rouge. 206 p. 
U.S.D.A. 1968. Agriculture requirements and upstream 

watershed development. Big Black River. 
Vanatta, E. G. 1910. Unionidae from Southeastern Arkan- 
sas and N.E. Louisiana. The Saul, ins 23:102-104. 



120 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



VARIATIONS OF SHELL MORPHOLOGY IN THE 

CAROLINA MARSH CLAM, POLYMESODA CAROLINIANA, 

FROM SOUTHEASTERN UNITED STATES (CORBICULIDAE) 

Courtney T. Hackney 

Department of Biological Sciences 

University of North Carolina at Wilmington 

Wilmington, NC 28406-3297 

ABSTRACT 

Polymesoda caroliniana (Bivalvia: Corbiculidae) representing 15 papulations 
from the Gulf and south Atlantic coasts of the U.S. were collected. Six morphome- 
tric measures of the shell were made on each clam collected. Physical characteris- 
tics of each site were also measured. Visually, at least three shell morphs were 
found; the very angular shell type from Yankeetown, Florida, the broad type from 
Redfish Point, Louisiana, and the common oval form from most other locations. 
When multivariate statistics were used (Principle Components) some differentia- 
tion of populations based on shell shape was apparent. The broad type from 
Louisiana was statistically different from the others. Other populations formed a 
continuum with overlap between populations. All populations were readily 
identified as P. caroliniana based on internal shell characters. No differentiation 
occurred between south Atlantic U.S. populations and Gulf populations. Popula- 
tions which differed from the typical form were generally from non-typical 
habitats. No physical characteristic of the site was correlated with different shell 
characters. 



The Carolina Marsh Clam, Polymesoda caro- 
liniana (Bosc, 1801) is found in brackish 
marshes from Texas to Virginia (Abbott 1954; 
Morris 1973) and is remarkably tolerant of a 
variety of stressful conditions including varia- 
tions in salinity (van der Schalie 1933; Gainey 
1976a, b; Gainey and Greenberg 1977; Deaton 
1981, 1982), anoxia (Pamatmat 1979), and desic- 
cation (Olsen 1976; Duobinis-Gray and Hackney 
1982). Polymesoda caroliniana is found in poor- 
ly flooded habitats (Subrahmanyam et al. 1976; 
Duobinis-Gray and Hackney 1982) and in perma- 
nently flooded communities (Swingle and Bland 
1974). Reproduction varies from once a year in 
well-flooded habitats (Olsen 1976) to several 
times a year in poorly flooded marshes (Hackney 
1983). With such diverse habitats over a large 
geographic range, the species exhibits varia- 
tions in shell morphology due likely to genetic 
and/or environmentally induced mechanisms. 

The following study examines populations of 
P. caroliniana from throughout the geographic 
range and from different environments and 
determines 1) if variations in shell morphology 



exist, and 2) if variations followed geographic 
patterns or were associated with physical 
characteristics of the site. 

Study Sites 

Estuaries from Maryland to eastern Texas 
were examined for populations of P. carolin- 
iana. Fifteen populations representing different 
parts of the geographic range and populations 
from "non-typical" Polymesoda habitats were 
chosen for study. The general location of these 
sites is shown in Figure 1 and specific site 
descriptions are as follows: 

Site 1. Intertidal marsh dominated by Junrus roemerianus 
on the southwest side of North Carolina Highway 1100, 
16 km south of Wilmington, NC. in New Hanover County. 
Site 2. Intertidal swamp along the inner reaches of an un- 
named tidal creek 0.5 km south of Ness Creek, a tributary 
of the Northeast Cape Fear River in New Hanover Coun- 
ty, North Carolina. 
Site 3. Intertidal marsh dominated by Spartina altemijlora 
on Battery Island. North Carolina, in Brunswick County. 
The population was located 20 m from the Cape Fear 
River on the NW side of the island. The population was 
found only in a small area of the high intertidal zone. 
Site 4. Intertidal marsh dominated by J. roemerianus in 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 121 



FIG. 1. General geographic location of collection 
sites along the Gulf and Atlantic coasts of the United 
States. Insert shows the location of the three collec- 
tion sites in the Cape Fear estuary, North Carolina. 




GULF OF MEXICO 



Faver-Dykes State Park in Flagler County, Florida. The 
specific site was 20 m east of the boat dock and picnic 
area 

Site 5. Subtidal in a tidal creek with an average depth of 10 
cm at low tide. The collecting site was under the bridge on 
U.S. Highway 1 which separates St. Johns County and 
Flagler County. Florida. 

Site 6. Intertidal, well-flooded marsh dominated by J. 
roemerianus approximately 6 km west of Yankeetown, 
Florida, Levy County, adjacent to a picnic area. 

Site 7. Fringing intertidal marsh dominated by J. roemeria- 
nus, approximately 0.75 km from the entrance to Ft. 
McAllister State Park on state road 144 in Chatham 
County, Georgia, approximately 26 km south of Savan- 
nah, Georgia. 

Site 8. Subtidal location along the marsh edge approximate- 
ly 5 m from Site 7. 

Site 9. Subtidal habitat in a shallow pond on a marsh domi- 
nated by ./. roemerianus. The site is approximately 0.7 
km NW of the Louisiana State Fisheries and Wildlife Sta- 
tion at Fearman Bayou in Vermillion Parish, Louisiana. 

Site 10. Intertidal marsh dominated by J. roemerianus on 
a small island located at the mouth of the Jourdan River, 
approximately 5 km north of Bay St. Louis, Mississippi, 
Hancock County. 

Site 11. Well-flooded intertidal marsh dominated by J. 



roemerianus where old U.S. Highway 90 crosses Davis 
Bayou, east of Ocean Springs, Mississippi in Jackson 
County. 

Site 12. Clams were found exposed on the edge of an inter- 
tidal marsh dominated by J. roemerianus and Sagittaria 
spp. on the most southern of the Twin Islands in the 
Pascagoula Estuary, Jackson County, Mississippi. 

Site 13. Intertidal marsh dominated by short form J. 
roemerianus and short form S. altemitlora near Bayou 
La Batre, Alabama, in Mobile County. The marsh was off 
Highway 188 where Coden Bayou and Portersville Bay 
intersect. 

Site 14. Intertidal marsh dominated by J. roemerianus 
located where a tidal creek crosses U.S. Highway 17, 25 
km north of the intersection of U.S. Highway 17 and 
Highway 41 North of Charleston, South Carolina, in 
Charleston County. 

Site 15. Intertidal marsh dominated by J. roemerianus 
located in Bellfontaine marsh south of Davis Bayou which 
is east of Ocean Springs, Mississippi in Jackson County. 

Methods and Materials 

At each site the following site characteristics 
were measured as follows. Salinity with a re- 
fractometer (AO model 10423) ± 0.5°/ oo . The 



122 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



water sample was squeezed from the sediment 
where the clams were collected. Soil compaction 
was determined with a standard soil penetro- 
meter (FSN 6635-679-5761). Between 3 and 10 
measurements were made depending on the 
variation at each site. Soil moisture was deter- 
mined by drying triplicate soil samples at 103°C 
and organic content by ignition of triplicate 
samples at 600°C for 6 h. Soil texture was deter- 
mined using the hydrometer method (Bouyoucos 
1927, 1928). 

At least 10 clams were randomly collected 
from each site. The goal was 20 clams from each 
site, but clams were rare at a few sites. Only live 
clams were used in the study. Clams were 
frozen, and later after thawing, the soft tissues 
were removed from the shell. The following 
measurements were made on each clam using 
calipers accurate + 0.2 mm: Length as the max- 
imum distance from the anterior to the posterior 
portion of the shell; width (i.e., height) as the 
distance from the dorsal margin of the umbo to 
the ventral margin at a 90° angle from the 
length; maximum width (height) as the greatest 
distance that could be measured from the dorsal 
margin of the umbo to the ventral margin; width 
(thickness) as the maximum distance from the 
umbo on the right valve to the same place on the 
left valve. Shell weight was determined after air 
drying at 103°C to a constant weight (± 0.05 g) 
on an Ohause top loading balance (B 300D). The 
area of the shell was a measurement determined 
by tracing the outside margin of the left valve on 
paper and then measuring the area of the trac- 
ing with a compensating Polar Planimeter (KE 
62 0005) accurate ± 0.01 cm 2 . 

Statistical Analysis 

Combinations of the measured variables were 
regressed on one another using the GLM pack- 
age in SAS 82.3 (SAS, 1982). Variables which 
were linearly related (r 2 >0.8) were used to pro- 
duce ratios which were used in the Principle 
( 'omponents Analyses. All variables were stand- 
ardized. This was necessary to satisfy the 
assumptions of the test and also eliminated site 
specific size related bias. Thus, shell morphology 
not shell size was the factor tested. Initially all 
ratms of variables that were linearly related 
used in the PRINCOMP package in SAS 
i SAS. 1982). When two ratios with a high 



degree of correlation to one another (>0.8) were 
found, one of the pair was omitted from the final 
analysis following general guidelines for the 
procedure. The principle components which 
allowed the greatest differentiation of popula- 
tions were used to produce plots which showed 
morphological similarities and differences 
among populations. 

Results 

A preliminary investigation of shell morphol- 
ogy found some differences in shell morphology 
among six populations (Hackney and Moorse 
1984). Furthermore, these variations were regu- 
lar enough to be quantified by as few as 10 clams 
from a population (Hackney and Moorse 1984). 
Based on the 15 populations examined in this 
study, three distinctive shell types were visually 
recognizable (Fig. 2). Broad clams (Fig. 2A) 
were collected only at Site 9 in Louisiana, a sub- 








B 





FIC. '1. Population variation of shell morphology in Polyrto - 
soda caroliniana. Type A represents Site 9 in Louisiana, 
type B the normal shell type, type C the highly angular 
ninrph best represented by the Vankeetown, Florida popula- 
tion, and type D the typical mixture of slightly angular and 
typical oval forms found at most sites. 



Vol. 99(4) 



October 31, 1985 



TIIK NAITIU'S VSA 



tidal population. Even small elams (<20 mm) 
showed the broad or elongated shell, character- 
istic of this population. Clams in this population 
commonly exceeded 40 mm in maximum length 
with a few reaching 60 mm. The most common 
form of P. caroliniana was the oval type (Fig. 
2B). This form dominated most sites and was 
present in all populations except sites 6 and 9. 
Clams at site 6 had very angular shells (Fig. 2C) 
and could easily be separated from other popula- 
tions. Specimens from this population were con- 
firmed as P. caroliniana (R. T. Abbott, personal 
communication). The angular characteristic was 
found in all size classes. Most sites contained 
clams which included oval as well as some slight- 
ly angular shells (Fig. 2D). In these collections 
larger clams tended to be more angular. The 
only other collection which was visually dif- 
ferent was one from site 2. This site was 
dominated by low salinity, low pH water from a 
blackwater river (Northeast Cape Fear River). 



Shells were thin and golden in color. 

Color of the internal shell was also examined. 
Shells were found which contained purple and/ 
or golden yellowish coloration. In some shells 
the typical white color was completely covered 
by one or more of these colors. Neither the color 
or extent of coloration was a consistant charac- 
teristic of any population and was not useful in 
distinguishing populations from one another. 

Three populations (Sites 1-3) from different 
habitats were collected from within the Cape 
Fear River estuary, NC, and represent a range 
of salinity from fresh to nearly marine (Table 1). 
There was some separation of these populations 
based on Principle Components composed of 
area/weight and area/width ratios (Fig. 3). 
There was overlap of the population (Site 1) 
from the typical P. caroliniana habitat, i.e. 
Juncus roemerianus marsh, with the salt marsh 
population (Site 3) and the tidal swamp popula- 
tion (Site 2). Shells from sites 3 and 2 could be 



TABLE 1. Physical characteristics of sites and numbers of Polymesoda clams measured. 



Site 
Number 


Number 
of Clams 
Measured 


Pore Water 
Salinity 0/00 


Mean 
Penetrometer 
Index 


Mean 

% Soil 

Moisture 


% 
Organic 
Con tent 


% 
Sand 


% 
Silt 


% 
Clay 


1 


126 


8 


30 


79 


52 


43 


7 


49 


2 


61 





7 


83 


58 


68 


17 


15 


3 


61 


26 


123 


42 


8 


54 


8 


38 


4 


10 


2 


101 


81 


26 


40 


5 


55 


5 


10 





20 


45 


5 


86 


6 


8 


6 


10 


6 


23 


28 


75 


64 


2 


34 


7 


12 


5 


130 


54 


10 


92 


8 





8 


20 


5 


11 


34 


5 


88 


8 


4 


9 


28 


3 





68 


9 


61 


31 


7 


10 


19 


* 
8 


14 


42 


1 1 


39 


35 


14 


11 


19 


4 


20 


64 


36 


24 


24 


14 


12 


20 


12 


21 


40 


9 


42 


27 


22 


13 


20 


* 

15 


19 


32 


6 


64 


13 


17 


14 


9 


20 


11 


75 


21 


66 


29 


5 


15 


20 


15 


4 


76 


24 


66 


29 


5 



Salinity determined by silver nitrate titration and conversion of chloride to salinity. Salinity 
0/00 = 0.030 + (1.8050 x chlorinity 0/00). 



124 THE NAUTILUS 



October 31, 1985 



Vol. 99(4) 



separated from one another with a high degree 
of certainty (Fig. 3). Shells from the Spartina 
tiltentijloru dominated sail marsh (Site 3) were 
heavy and rounded while those from the tidal 
swamp (Site 2) were round and light. Genetic 
differences have been demonstrated for other 
mollusk species along environmental gradients 
(Levington 1973; Koehn et al. 1976). 

When shells from all Atlantic coast popula- 
tions were examined the same shell characteris- 
tics (area/weight and area/width) again provided 
the best resolution via Principle Components 
Analysis (Fig. 4). Shells from sites 4 and 14 had 
about the same area/width values as site 3 while 
sites 7, 8, and 5 were intermediate to sites 1 and 
2 (Fig. 4). Site characteristics at sites 14 and 3 
were similar in that they were more saline 
(Table 1), but site 4 was a low salinity site and 
clams at this site were subtidal. Shells from 
sites 4 and 14 could be statistically separated 
from sites 2 and 5 with a high degree (95%) of 
certainty. 

Populations from the Gulf of Mexico were best 
segregated from one another by different princi- 
ple components, namely weight/maxwidth and 
height/width ratios. Shells from sites 9 and 11 
were easily separated from one another (Fig. 5) 
and there was only a slight degree of overlap 
between sites 9 and 10 (Fig. 5). Shells from site 
9 (Fig. 2A), as noted previously, were morphol- 
ogically distinct, as were those from site 6. 
Shells from sites 6 and 9 exhibited a high degree 
of overlap (Fig. 5) even though their appearance 
was different (Figs. 2A and 2C). Most of the 
remaining Gulf populations exhibited a high 
degree of similarity (Fig. 5). 

When all 15 populations were combined one 
principle component from the Gulf of Mexico 
analysis and one from the Atlantic coast 
emerged as the two most important (Fig. 6). 
Separation of populations previously noted, i.e. 
sites 9 from 11 and 2 from 3 remain (Fig. 6). 
Also shells from sites 14 and 4 were distinctly 
different from sites 11 and 6. Shells from site 9 
were again distinctly different from all other 
populations (Fig. 6). Although separation is 
possible between some of the populations v\ hen 
viewed as a whole they form a continuum 
(Fig. 6). 

Discussion 

Populations separated by great distances, or a 



3 


CAPE FEAR POPULATIONS 






1 


2 











COMPONENT 2 (AREA/WIDTH) 

FIG. 3. Principle Components plots of the Cape Fear popu- 
lations. Component 1 was the most important variable in 
distinguishing between populations while component 2 was 
second. Site numbers represent means of each population for 
each component. Elipses represent 95% of all members of 
the population. Scale on the X and Y axis are irrelevant. 



ATLANTIC POPULATIONS 




COMPONENT 2 



(AREA/WIDTH) 



FIG. 4. Principle components plot of all Atlantic coast 
populations. Means of sites are represented by their respec- 
tive numbers. Elipses drawn around each mean represent 
95% of all members of each population. Populations without 
elipses contain the same 95% limits as those represented by 
populations 1, 2 and 3. 




COMPONENT 2 



(HEIGHT/WIDTH) 



FIG. 5. Principle components plot of all Gulf populations. 
Site numbers represent means for each. Elipses drawn 
around means of populations from sites 9, 10, and 1 1 repre- 
sent 95% of the population. Other populations contain the 
same size elipses. 



Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 125 



i 
i- 

Q 

< 

cr 

< 



z 
o 
a. 
5 
o 
o 




COMPONENT 



(WEIGHT/MAXWIDTH) 



FIG. 6. Principle components plot of all populations. Site numbers represent the means of 
each. Elipses drawn around means represent 95% of all clams in each population. Elipses 
are not drawn around all populations but are the same size for each. 



barrier such as the peninsula of Florida, might 
be expected to have begun the process of genetic 
differentiation. Polymesoda populations do not 
show such differentiation, at least as reflected in 
shell morphology. With the exception of popula- 
tion 9 (Louisiana) there was almost total overlap 
between the Atlantic and Gulf populations (Fig. 
6). Variations in shell morphology have been 
shown to exist in Littorina saxatilis and were 
correlated with genetic differences related to 
environmental pressures (Janson and Ward 
1984). Differences may occur between mollusk 
populations separated by only one meter if en- 
vironmental pressures are different, such as in a 
surf zone (Janson and Ward 1984). Most of the 
populations examined in this study were from 
similar habitats, i.e. irregularly flooded Juncus 
marshes with thick root mats in acidic soil. Such 
rigorous environments are likely to exert strong 
selection pressures on filter feeding bivalves 
and genetic differences are masked by the need 
of populations to conform critical features such 
as shell shape and structure. This is character 
convergence at the species level. 

The three populations from the Cape Feat- 
River show a clinal trend from high to low salin- 
ity (Fig. 3). Shell morphology has been shown to 
change with distance up an estuary in the case 
of L. saxatilis (Newkirk and Doyle 1975). Such a 
trend suggests salinity as a factor related to 
shell shape, but the trend does not continue if all 



populations are examined (Fig. 6 and Table 1). 
Measuring salinity one time during collection of 
clams may not be enough to correctly describe a 
habitat. 

Populations which were readily discernible 
either through principle components analysis or 
visual means were from atypical habitats. Popu- 
lation 9 was from a soft substrate in a subtidal 
pond. Population 6 contained very angular 
clams and was also from a soft substrate and 
well-flooded habitat. Population 2 was in a tidal 
swamp where the pH of the water is very low for 
long periods of time due to the influence of a 
nearby blackwater river. A variety of environ- 
mental factors can affect shell growth and 
development in bivalves (Tevesz and Carter 
1980; Burky 1983) including temperature, pH, 
dissolved ions in the water, hydrography, and 
substrate. Morphological differences between 
populations may not be detected through elec- 
trophoretic studies (Janson and Ward 1984) 
because they may not be the result of genetic 
differences between populations or the wrong 
allozymes were selected for study. 

Although P. caroliniana populations have 
been identified which can be distinguished from 
others, through visual as well as statistical 
means, the important characters for identifica- 
tion are the narrow, external ligament, the 
three subequal cardinal teeth, the one anterior 
lateral tooth and the one posterior lateral tooth 



126 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



which does not extend to the posterior adductor 
scar (Heard 1982). 

Acknowledgments 

I thank Mark LaSalle and Sam Faulkner for 
collecting specimens from Mississippi and for 
analyzing those sediments. T. Dale Bishop and 
Olga J. Pendleton read an early draft of the 
manuscript and made many helpful comments. 
Rosemarie Ganucheau kindly drew Figure 2. 

LITERATURE CITED 

Abbott, R. T. 1974. Amr run a Scashells. Second edition. Van 
Nostrand/Reinhold Co., New York. 663 pp. 

Buoyoucos, G. J. 1927. The hydrometer as a new and rapid 
method for determining the colloidal content of soils. Soil 
Science 23:319-330. 

1928. Making mechanical analyses of soils in 

fifteen minutes. Soil Science 25:473-480. 

Burky, A. J. 1983. Physiological ecology of freshwater 
bivalves, pp. 281-327 in V. 6 The Mollusca, W. D. Russell- 
Hunter, ed. Academic Press, NY. 

Deaton, L. E. 1981. Ion regulation in freshwater and 
brackish water bivalve mollusks. Physiological Zoology 
54:109-121. 

1982. Tissue (Na+ Reactivated adenosine- 
triphosphatase activities in freshwater and brackish water 
bivalve molluscs. Marine Biology Letters 3:107-112. 

Duobinis-Gray, E. M. and C. T. Hackney. 1982. Seasonal and 
spatial distribution of the Carolina Marsh Clam, Poly- 
mesoda caroliniana (Bosc). in a Mississippi tidal marsh. 
Estuaries 5:102-109. 

Gainey, L. F., Jr. 1978a. The response of the Corbiculidae 
(Mollusca: Bivalvia) to osmotic stress: the cellular re- 
sponse. Physiological Zoology 51:79-91. 

1978b. The response of the Corbiculidae (Mollus- 
ca: Bivalvia) to osmotic stress: the organismal response. 
Physiological Zoology 51:68-78. 

Hackney, C. T. 1983. A note on the reproductive season of 
the Carolina Marsh Clam, Polymesoda caroliniana (Bosc), 
in an irregularly-flooded Mississippi marsh. Gulf Research 
Reports 7:281-284. 

Hackney, C. T. and C. S. Moorse. 1984. Variations of shell 
morphologj in the Carolina Marsh Clam, Polymesoda 
caroliniana, related to environmental factors. Associa- 
tion of Southeastern Biologists Bulletin 31:60. 



Heard, R. W. 1982. Guide to common tidal marsh inverte- 
brates of the northeast Gulf of Mexico. Mississippi- 
Alabama Sea Grant Consortium, MASGC-79-004, 82 p. 

Janson, K. and P. Sundberg. 1983. Multivariate morpho- 
metric analysis of two varieties of Littorina saxatilis 
from the Swedish west coast. Marine Biology 74:49-53. 

Janson, K. and R. D. Ward. 1984. Microgeographic variation 
in allozyme and shell characters in Littorina saxatilis 
Olivi (Prosobranchia: Littorinidae). Biological Journal of 
the Linnean Society 22:289-307. 

Koehn, R. K., R. Milkman and J. B. Milton. 1976. Population 
genetics of marine pelecypods. IV. Selection, migration, 
and genetic differentiation of the blue mussel, Mytilus 
edulis. Evolution 30:2-32. 

Levington, J. 1973. Genetic variation in a gradient of en- 
vironmental variability: Marine Bivalvia (Mollusca). 
Science 180:75-76. 

Morris, P. A. 1973. A field guide to shells of the Atlantic 
coast and the West Indies. Houghton Mifflin Co., Boston, 
MA, 330 p. 

Newkirk, G. F. and R. W. Doyle. 1975. Genetic analysis of 
shell shape variation in Littorina saxatilis. Marine 
Biology 30:227-237. 

Olsen, L. A. 1976. Reproductive cycles of Polymesoda caro- 
liniana (Bosc) and Rangia cuneata (Gray) with aspects of 
desiccation in the adults and fertilization and early larval 
stages in P. caroliniana. Ph.D. Dissertation. Florida 
State University, Tallahassee, FL, 117 p. 

Pamatmat, M. M. 1979. Anaerobic heat production of bi- 
valves (Polymesoda caroliniana and Modiolus demissus) 
in relation to temperature, body size, and duration of 
anoxia. Marine Biology 53:223-229. 

SAS Institute Inc. 1982. SAS Users Guide: Statistics. SAS 
Institute Inc., Cary, NC, 584 pp. 

Subrahmanyam, C. B., W. L. Kruczynski and S. H. Drake. 
1976. Studies on the animal communities in two north 
Florida marshes. Part II. Macroinvertebrate communities. 
Bulletin of Marine Science 26:172-195. 

Swingle, H. A, and D. G. Bland. 1974. Distribution of the 
estuarine clam Rangia cuneata Gray in coastal waters of 
Alabama. Alabama Marine Resea7-ch Bulletin 10:9-16. 

Tavesz, M. J. and J. G. Carter. 1980. Environmental rela- 
tionships of shell form and structure of unionacean 
bivalves, pp. 295-322 in Skeletal Growth of Aquatic 
i )rgtmi> m. . I > ( '. Rhoads and R \ 1 ,utz, eds Plenum 
Press, N. Y. 

van der Schalie, H. 1933. Notes on the brackish water 
bivalve Polymesoda caroliniana (Bosc). Occasional Papers 
of the Museum of Zoology. University of Michigan 258:1-9. 



Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 127 /* J 



GROWTH AND OPTIMUM SEEDING TIME FOR THE HARD CLAM, 
MERCENARIA MERCENARIA (L.), IN COASTAL GEORGIA 

Randal L. Walker 

Marine Extension Service 

University of Georgia 

P.O. Box 13687 

Savannah, GA 31416-0687 

ABSTRACT 
Instantaneous growth rates of the hard clam, or Quahog, Mercenaria 
mercenaria (L.), in Georgia were studied to determine the best time to seed clams 
to obtain maximum growth. Clam growth occurs in two distinct phases. During 
the first phase, juveniles grow continuously throughout the year with most rapid 
g?'owth in the spring and declining growth through the summer, fall and winter. 
In phase two, the growth of clams approximately 1 V2 years old oscillates with 
decreasing amphitude over time. Because, in Georgia, juvenile clams grow most 
rapidly during the spring that time or late winter is considered the best for 
seeding to obtain maximum yields. 



Introduction 

The coastal waters of Georgia support approx- 
imately 450,000 acres of salt marsh or ap- 
proximately 33% of the salt marshes along the 
Atlantic seaboard. During the early part of the 
century, these marshes supported a large oyster 
and small clam fishery. Today, the oyster in- 
dustry is almost non-existent (Harris, 1980), and 
clamming is sporadic (Walker et al., 1980; 
Walker, 1984a). This is unfortunate because 
most of the coastal waters of Georgia are rela- 
tively free of pollution and are suitable for the 
commercial culturing of shellfish. 

As more northern waters are closed to shell- 
fishing due to pollution (National Marine 
Fishery Service, 1977), the opportunity to use 
the coastal waters of Georgia for shellfish 
culture increases. Hard clams, or the Northern 
Quahog, Mercenaria mercenaria (Linnaeus, 
1758), grow rapidly throughout the year in 
southern waters (Menzel, 1963; Eldridge et al, 
1976; Walker, 1984b). In South Carolina, clam 
growth occurs throughout the year but varies 
seasonally (Eldridge et al.. 1976). In Florida, 
growth is most rapid in fall and spring, slower in 
winter and slowest in summer (Menzel, 1963; 
1964). In contrast, growth in northern waters 
ceases during winter when water temperature 
cool to 5 to 6°C (Loosanoff, 1939). Most rapid 
growth is in the summer when water tempera- 



tures reach 20°C (Ansell, 1968). 

The culture of hard clams may be one means 
of increasing shellfish production in Georgia. 
Clams planted at 6-mm in shell length at a den- 
sity of 509/m 2 within predator exclusion cages 
grow to commercial size (44.4-mm in shell 
length) within 17 months with good survival 
rates (Walker, 1984b). However, to assure high 
survival rates, crab larvae which entered cages 
had to be removed monthly, until clams reached 
a shell length of approximately 20-mm. At 
larger sizes, they were immune to predation by 
small crabs. 

By determining the optimum time for seeding 
clams, it may be possible to decrease the time re- 
quired to obtain a marketable product. Eldridge 
et al. (1979) observed that clams in South 
Carolina grew best in spring and fall and recom- 
mended seeding in the fall. Earlier Eldridge et 
al. (1976) reported that clam grew best in spring 
and summer. These conflicting reports suggest 
that fall may not be the best planting time for 
clams in southern waters. 

The purpose of the research reported here 
was to determine the optimum seeding time for 
obtaining maximum growth of hard clams in the 
coastal waters of Georgia. 

Materials and Methods 

The growth of three stocks of hard clams from 



128 THE NAI'TIU'S 



October 31, 1985 



Vol. 99 (4) 



Georgia, Massachusetts and Virginia stocks 
were compared. Local clams, collected from 
iicar Cabbage Island, Savannah, Georgia, were 
shipped to Virginia Institute of Marine Science 
(VIMS), Eastern Shore Laboratory, Wacha- 
preague, Virginia, where they were spawned. 
Their offspring were returned to Georgia when 
they had grown to a shell length of 10.4 ± 1.2 
(SD) mm. VIMS also supplied a fast growing 
stock of Virginia clams with a mean shell length 
of 11.0 ± 1.2 (SD) mm. A third stock (12.8 ± 1.8 
mm), also selectively bred for rapid growth, was 
obtained from Martha's Vinyard Shellfish 
Group, Oak Bluffs, Massachusetts. 

The clams were planted on November 30, 
1980 near Cabbage Island (Fig. 1) in 1 x 1 x 0.3 m 
cages constructed of 6-mm vexar plastic. Three 
replicate cages per stock were seeded at a densi- 
ty of 1000 clams/m 2 . The cages were buried in a 
sandy substrate to a depth of 0.15 m and the 
enclosed bottom was layered with 5 cm of gravel 
aggregate in an attempl to minimize crab preda 
tion (Castagna and Kraeuter, 1977). The corners 
of the cages were attached to 1 m stakes. 



All cages were sampled seasonally over two 
years by sieving all of the sediment through a 
5-rnm screen. The clams were counted and their 
shell length measured (the longest possible 
measurement, i.e., anterior-posterior) to the 
nearest 0.1-mm with vernier calipers. Sediment 
and clams were then returned to their respec- 
tive plots. Two cages (1 x 1 x 0.5 m) constructed 
of 3-mm-mesh vexar plastic attached to a frame 
of 13-mm steel reinforcement rods were divided 
into nine compartments of 0.11 m 2 each. Cages 
were buried to a depth of 0.25 m on an intertidal 
sandflat near Cabbage Island, Georgia in May 
1982 (Fig. 1). In June 1982, 6-mm seed clams 
supplied by Aquaculture Research Corporation 
were planted and maintained at the following 
replicate densities: 56, 111, 222 and 333 
clams/0. 11m 2 or the equivalent to 509, 1009, 
2018 and 3027 clams/m 2 , respectively. The 
center compartment of the cage was seeded 
with approximately 500 clams to replace those 
that died. In the other cage, clams with an 
average shell length of 39 mm, were planted at 
the following densities: 10, 25 and 45 clams/ 




il', 1. Map of Wassaw Sound, Georgia showing experimental growing site at Cabbage Island. 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 129 



0.11m 2 or the equivalent to 91, 227 and 409 
clams/m 2 . 

Cage I (6-mm clams) was sampled monthly 
while Cage II was sampled seasonally. In each 
case clams, crabs and sediment to a depth of 
0.25 m were sieved through a 5-mm screen. 
Clams were counted, the shell length of a sub- 
sample (N = 70) measured and clams were added 
if needed to keep the density constant in each 
compartment. Crabs were identified to species, 
measured for carapace width and discarded. 
After January 1983, Cage I was sampled sea- 
sonally because survival had remained at ap- 
proximately 100% for several months (Walker, 
1984b). 

Clams (N= 174) from field populations located 
near Cabbage Island were used to determine the 
relationship between shell length and ash-free 
dry weight (AFDW). After they were measured 
to the nearest mm, the flesh was removed and 
dried to constant dry weight at 80 °C for 48 
hours. Ash weight was determined by combust- 
ing the sample at 475°C for 16 hours and ash- 
free dry weight determined by difference. The 
resulting equation is: g AFDW = 0.00000726 
(shell length in mm) 2.98, r 2 = 0.99. 

The instantaneous growth value G equals the 
instantaneous increase in meat weight over 
given time intervals (seasons in this case). G is 
calculated as Ln(Wt/Wo) where o and t repre- 
sent the beginning and end of each time inter- 



val. The ash-free dry weight value (W) was 
determined by taking the mean shell length at 
each sampling and inserting that value into the 
above shell length to mean individual meat ash- 
free dry weight regression equation. An exam- 
ple is given in Table 1 . 

Results 

Instantaneous growth values (G) for the three 
clam stocks are given in Table 2 and values ob- 
tained at different clam densities per age class 
are given in Table 3. Older clams grew well in 
fall and spring, with moderate growth in sum- 
mer and poor growth in winter. The growth of 
the to 1 year old clams did not show the 
characteristic reductions in growth during the 
summer; however, the reduced growth in winter 
is apparent. This phenomenon is observed both 
in the stock seed clams' first summer (Table 2; 
Summer 1981) and in the seed clam density ex- 
periment (Table 3; Summer of 1982 and 1983). 
However it is not observed among older clams 
or in the second year of the stock experiment. 

Clam growth in Georgia appears to go 
through two phases (Fig. 2). During the first 
phase, clams to approximately IV2 years in age 
appear to grow in a linear fashion with most 
rapid growth in the spring and decreasing 
growth through the following seasons. In the 
second phase, clam growth oscillates with 
decreasing amphitude over time. 



TABLE 1. Growth data for the hard clam. Mercenaria mercenaria, cage planted with 
yearlings at a density of 91/m 2 





Mean shell 


Mean Ind: 


Lvidual 


Instantaneous Growth 


Date 


length in mm 


Wgt in g 


AFDW 


(G) 


June 1982 


39.9 


0.4284 




0.15 


September 1982 


42.0 


0.4991 




0.32 


December 1982 


46.7 


0.6847 




0.07 


March 1983 


47.7 


0.7293 




0. 19 


June 1983 


50.8 


0.8799 




0.08 


September 1983 


52.2 


0.9514 




0. 18 


December 1983 


55.3 


1.1331 




0.06 


March 1984 


56.5 


1.2079 




0.18 


June 1984 


60. 1 


1.4485 




0.10 


September 1984 


62.2 


1.6085 




0. 14 


December 1984 


65.1 


1.8425 







130 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



Discussion 

The two phase growth pattern for hard clams 
in southeastern Atlantic coast waters can be ex- 
plained in terms of poor growth conditions in 
winter and the reproductive cycle of clams. 
Clams in Georgia and South Carolina exhibit a 
distinct bimodal reproductive cycle (Pline, 1984; 
Eversole et al., 1980) with spawning occurring 
from spring well into fall. The peak spawning 
periods of Georgia clam populations is in May 
and October (Pline, 1984), while in South 
Carolina peaks are in May to June and in 
September to October (Eversole et al., 1980). 
According to Belding (1931), clams in 
Massachusetts reach sexual maturity at shell 
lengths of 32 to 38 mm. Thus maturity is related 
to size rather than age. In South Carolina 
populations, a small percent of males and 
females spawned at an approximate average 
shell length of 18 to 22 mm (Eversole et al., 
1980; Fig. 2; Eldridge et al, 1979; Table 4); 
however, most clams did not spawn until they 
reached an average size of 28 to 32 mm. Thus, 



until clams are approximately 1 to IV2 years old, 
energy is used for growth rather than reproduc- 
tion resulting in the seasonally linear decline 
clam growth between spring and winter. When 
sexual maturity is reached, clam growth in sum- 
mer is reduced because some clams continue to 
spawn while others regenerate biomass lost dur- 
ing spring spawning. The result is cyclic growth. 
The results of this work are comparable to 
other studies of hard clam growth in south- 
eastern United States. In this area, clams grow 
year around with most rapid growth in spring 
and fall (Eldridge et al, 1976, 1979; MenzeL 
1963). Mercenaria mercenaria seed clams, ob- 
tained from a Connecticut hatchery, and grown 
in coastal Florida grew well in spring and fall 
with slow growth in winter and least growth in 
summer. However, with naturally occurring 
sets of Mercenaria campechiensis Gmelin seed 
clams growth was best in spring and fall, rapid 
in summer and slowest in winter (Menzel, 1963). 
In Georgia, Mercenaria mercenaria grew best 
in spring and fall with little growth in winter 



TABLE 2. Instantaneous growth values per season per hard clam, Mircc/iurm mercenaria, stuck from fall 1980 to fall 
1982. Data is from Walker (1984a). 



STOCK 



Fall 80 Win 81 Spr 81 Sum 81 Fall 81 Win 82 Spr 82 Sum 82 Fall 82 



Georgia 


0.26 


0.91 


1.10 


.0.75 


0.44 


Massachusetts 


0.05 


0.47 


0.80 


0.55 


- 


Virginia 


0.A8 


1.02 


1.27 


0.85 


0.34 



0.25 



0.38 0.28 



0.25 0.21 



0.2C 



0.33 



0.19 



TABLE '.i. Instantaneous growth values ((!) per season per hard clam, Mercenaria mercenaria, density per age class 
from summer 1982 to fall 1984. Instantaneous growth values for the seed clams arc from data reported in Walker (1984b) 
and those for the one year old clams (yearlings) are from unpublished data. 



DENSITY 


Sum 82 


Fall 82 


Win 83 


Spr 83 


Sum 83 


Fall 83 


Win 84 


Spr 84 


Sum 84 


Fall 84 


Seed Clams 






















509/m 2 


2.15 


1.75 


0.48 


0.82 


0.68 


0.34 


0.05 


0.33 


0.18 




1009/m 2 


2.38 


1.64 


0.40 


0.74 


0.56 


0.20 


0.04 


0.18 


0.03 




2018/m 2 


2.13 


1.74 


0.40 


0.72 


0.23 


0.10 


0.08 


0.15 


0.02 




3027/m 2 


2.18 


1.62 


0.39 


0.67 


0.01 


0.18 


0.05 


0.00 


0.03 




YEARLINGS 






















91/m 2 


0.15 


0.32 


0.07 


0.19 


0.08 


0.18 


0.06 


0.18 


0.11 


0. 14 


227/m 2 


0.17 


0.31 


0. 16 


0.19 


0.11 


0.19 


0.05 


0.16 


0.10 


0.09 


409/m 2 


0.21 


0.27 


0.12 


0. 18 


0.13 


0.20 


0.03 


0.14 


0.10 


0.06 



Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 131 



1 10 
1.00 
090 
080 



a 



c 70 

J 

o 

O 060 
w 

I 

s 

2 040 
to 

C 

30 



20 - 
10 - 



— G values for Seed Clams 
planted at 509/ m 2 

G values for the Georgia 
Stock Clams 

— G values for the yearling 
clams planted at 91 m 2 




Spr Sum Fall Win Spr Sum Fall Win Spr Sum Fall Win Spr Sum Fall Win 

Time in Seasons 

FIG. 2. Growth of hard clams, Mercenaria mercenaria, grown in predator exclusion cages 
on Cabbage Island, Wassaw Sound, Georgia. 



(Godwin, 1968) while no clam growth data was 
obtained from the summer period, growth in 
August was approximately 10% of the total ob- 
tained during the experiment. Mercenaria 
mercenaria seed clams from a North Carolina 
hatchery which were planted in coastal South 
Carolina grew best in spring and fall, with least 
growth in winter (Eldridge et al., 1979). In an 
earlier study, clam growth was reported best in 
spring and summer (Eldridge et al., 1976). 

These conflicting reports of clam growth pat- 
terns in South Carolina can be explained if one 
recognizes that there are two seperate phases of 
clam growth. For the first study (Eldridge et al., 
1976), clam growth was determined over 15 
months compared to 33 months in the later 
study (Eldridge et al., 1979). Assuming that the 
ash-free dry weight to shell length regression 
equation can be applied to those in South 
Carolina, the instantaneous growth values for 
the two South Carolina clam studies, based on 
shell lengths reported, are given in Table 4 and 



5. This data shows that the growth patterns of 
South Carolina clams are similar to those in 
Georgia (Table 3; Fig. 2) over comparable time 
periods. In Eldridge et al. (1979), growth with 
time (33 months) shows that clam growth is best 
in fall and spring; however, if one examines only 
the first 15 months of the study, one would con- 
clude that clams grew best in summer and fall. 

Data presented in this report and that above 
suggest that optimum clam growth in Georgia 
and South Carolina depends upon age of the 
clam and planting time. From set to approx- 
imately IV2 years of age, clams grow well in 
spring, summer and fall depending upon seeding 
time, but do not grow well in winter. Older 
clams grow well in spring and fall, moderately in 
summer and poorly in winter. 

Planting time may be an important factor in 
clam growth and in survival. Eldridge et al. 
(1979) recommended seeding South Carolina 
seeding areas at 300 clams/m 2 in fall. Based on 
the results of my studies which show that clam 



132 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



TABLE 4. Instantaneous growth values (G) per season as calculated from clam growth 
data for clams planted at 290/m 2 in Clark Sound, South Carolina as reported in Table 3 of 
Eldridge et al (1976). 





Mean She 


11 


Mean Individual 


Instantaneous Growth 


Dace 


1 engl h in 


on 


Wgt in g 


AFDW 


(G) 


March 1974 


17.29 




0.0354 




1.07 


June 1974 


24.78 




0.1036 




0.90 


September 1974 


33.51 




0.2547 




0.41 


December 1974 


38.47 




0.3842 




0.25 


March 1975 


41.81 




0.4924 




0.31 


June 1975 


46.34 




0.6691 







TABLE 5. Instantaneous growth values (G) per season as calculated from clam growth 
data for clams planted intertidally at 290/m ! in Clark Sound, South Carolina as reported in 
Table 4 of Eldridge et al. (1979). 





Mean Shell 


Mean Individual 


Instantaneous Growth 


Date 


length in mm 


Wgt In gAFDV 


(G) 


June 1975 


13.86 


0.0183 


0.88 


September 1975 


18.62 


0.0442 


0.92 


December 1975 


25.33 


0.1106 


0.63 


March 1976 


31.25 


0.2068 


0.64 


June 1976 


38.77 


0.3932 


0.18 


September 1976 


41.12 


0.4686 


0.22 


December 1976 


44.34 


0.5867 


0.12 


March 197 7 


46.15 


0.6609 


0.33 


June 1977 


51.56 


0.9197 


0.08 


September 1977 


52.91 


0.9933 


0.03 


December 1977 


53.36 


1.0187 


0.08 


March 1978 


54.77 


1.1010 





growth during the to IV2 year stage does not 
decline appreciably during the summer, I recom- 
mend seeding in late winter or early spring. If 
planted in early spring, clams will pass through 
three seasons of good growth before reducing 
growth in the winter. Furthermore, if planted in 
early spring or late winter, clams may grow to a 
sufficient size to prevent their predation by new- 
ly metamorphosed crabs which enter the cages. 
Blue crab, Callinectes sapidus Rathbun, spawn- 



ing occurs between early May and October in 
Chesapeake Bay (Van Engle, 1958), from March 
to September in Georgia (Palmer, 1974) and 
from February to October in Florida (Tagatz, 
1968). The peak spawning of blue crabs is from 
June to October. Mud crabs, Panopeus herbstii 
(Milne-Edwards), spawn from late spring 
through summer in South Carolina with great- 
est numbers of newly metamorphosed crabs oc- 
curring in July and August (Dame and Vern- 



Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 133 



burg, 1982) and from February to October in 
Florida with peak spawning in June and October 
(Tagatz, 1968). Thus, clams planted in late 
winter or early spring may grow to a size suffi- 
cient to prevent predation by newly metamor- 
phosed crabs before the peak spawning season 
of crabs is reached. 

Acknowledgments 

The author wishes to thank Dr. D. Menzel for 
reviewing the manuscript. Special thanks are 
given to Ms. A. Boyette and S. Mcintosh for the 
graphics. The work was supported by the 
Georgia Sea Grant Program, under Grant No. 
USDL-RF/8310-21-RR100-102. 

LITERATURE CITED 

Ansell, A. D. 1968. The rate of growth of the hard clam, 
Mercenaria mercenaria (L.), throughout the geographical 
range. J. Cons. Perm. int. Explor. Mer. 31:364-409. 

Belding, D. L. 1931. The quahog fishery of Massachusetts. 
The Commonwealth of Massachusetts, Marine Fishery 
Series No. 2, 41 pp. 

Castagna, M. A. and J. N. Kraeuter. 1977. Mercenaria cul- 
ture using stone aggregate for predator protection. Proc. 
Natl. Shellfish. Assoc. 67:1-6. 

Dame, R. F. and F. J. Vernburg. 1982. Energetics of a popu- 
lation of mud crabs, Panopeus herbstii (Milne-Edwards), in 
the North Inlet Estuary, South Carolina. Journ. Exp. 
Mar. Biol. Ecol. 63:183-193. 

Eldridge, P. J., W. Waltz, R. C. Gracy and H. H. Hunt. 1976. 
Growth and mortality rates of hatchery seed clams, Merce- 
nann itu m nana, in protected traj - in waters of South 
Carolina. Proc. Natl. Shellfish. Assoc. 66:13-20. 

Eldridge, P. J.. A. G. Eversole and J. M. Whetstone. 1979. 
Comparative survival and growth rates of hard clams, 
Mercenaria mercenaria. planted in trays subtidally and 
intertidally at varying densities in a South Carolina 
estuary. Proc. Natl. Shellfish. Assoc. 69:30-39. 

Eversole, A. G.. W. K. Michener and P. J. Eldridge. 1980. 
Reproductive cycle of Mercenaria mercenaria in a South 
Carolina Estuary. Proc. Natl. Shellfish. Assoc. 70:22-30. 

Godwin, W. F. 1968. The growth and survival of planted 
clams, Mercenaria mercenaria, on the Georgia coast. 



Georgia Game and Fish Commission Contribution Series 
No. 9, 16 pp. 

Harris, D. C. 1980. Survey of the intertidal and subtidal 
oyster resources of the Georgia coast. Georgia Dept. Natl. 
Resources, Coastal Resources Div.. Brunswick, Georgia. 
44 pp. 

Loosanoff, V. L. 1939. Effects of temperature on shell 
movements of clams, Venus mercenaria (L.). Biol. Bull. 
76:171-182. 

Menzel, R. W. 1963. Seasonal growth of northern quahog, 
Mercenaria mercenaria, and the southern quahog, 
Mercenaria campechiensis, in Alligator Harbor, Florida. 
Proc. Natl. Shellfish. Assoc. 52:37-46. 

Menzel, R. W. 1964. Seasonal growth of northern and south- 
ern quahogs, Mercenaria mercenaria and M. campechien- 
sis, and their hybrids in Florida. Proc. Natl. Shellfish. 
Assoc, 53:111-119. 

National Marine Fishery Service, 1977. The mollusean shell- 
fish industries and water quality: Problems and oppor- 
tunities. U. S. Dept. of Commerce, NOAA, Natl. Mar. 
Fish. Serv., Off. Fish. Devel., Supt. Docs., Washington. 
D.C. v + 46 pp. 

Palmer, B. A., 1974. Studies on the blue crab (Callinectes 
sapidus) in Georgia. Georgia Dept. Nat. Resources, 
Brunswick, Georgia. Contribution Series No. 29, 59 pp. 

Pline, M. J. 1984. Reproductive cycle and low salinity stress 
in adult Mercenaria mercenaria (L.) of Wassaw Sound, 
Georgia. Masters Thesis, School of Applied Biology. 
Georgia Institute of Technology, Atlanta, Georgia. 74 pp. 

Tagatz, M. D. 1968. Biology of the blue crab, Callinectes 
sapidus Rathburn, in the St. Johns River, Florida. Fish. 
Bull, 67:17-33. 

Van Engle, W. A. 1958. The blue crab and its fishery in 
Chesapeake Bay. Part I: Reproduction, early develop- 
ment, growth and migration. Comm. Fish. Review 
20:6-17. 

Walker, R. L. 1984a. Population dynamics of the hard clam, 
Mercenaria mercenaria (Linne) and its relation to the 
Georgia hard clam fishery. Masters Thesis, School of 
Applied Biology. Georgia Institute of Technology, Atlanta, 
Georgia. 121 pp. 

1984b. Effects of density and sampling time on 

growth of the hard clam, Mercenaria mercenaria, planted 
in predator-free cages in coastal Georgia. The Nautilus 
98:114-119. 

Walker, R. L., M. A. Fleetwood and K. R. Tenore. 1980. The 
distribution of the hard clam, Mercenaria mercenaria 
(Linne), and clam predators in Wassaw Sound, Georgia. 
Georgia Marine Science Center. Tech. Rept. 80-8. 59 pp. 



134 THE NAUTILUS October 31, 1985 Vol. 99(4) 

ANATOMY OF OXYLOMA NUTTALLIANA CHASMODES PILSBRY 

Dorothea S. Franzen 

Illinois Wesleyan University 
Bloomington, IL 61701 

ABSTRACT 

Shell characteristics, anatomical features of reproductive organs, radula and 
jaw, pigmentation of body and habitat of the -pulmonale, succineid gastropod, 
Oxyloma nuttalliana chasmodes are described from the University of Washington 
campus, Seattle, King County, Washington. 



H. A. Pilsbry (1948) described Oxyloma nut- 
talliana subspecies chasmodes from its shell. He 
reported the subspecies from only the type 
locality, Stockton, California. In early August, 
1983, 1 collected from the bases of short grasses, 
on the wet ground of the unshaded shore of 
Union Bay, at the edge of the campus of the Uni- 
versity of Washington, Seattle, King County, 
Washington, a succineid gastropod which I have 
identified as 0. nuttalliana chasmodes Pilsbry 
after comparing the shell with characters as 
described and figured by Pilsbry (Pilsbry, 1948, 
pp. 795-796, Fig. 426) and with the holotype (our 
Fig. 1, E, F) and paratypes (our Fig. 1, C, D) 
from the collection of the Academy of Natural 
Sciences of Philadelphia, no's. 5609 and 5609a. 

Anatomical features, pigmentation of the 
body, as well as shell characters need to be 
employed in the identification of succineid 
gastropods. I am describing shell, body features 
and anatomy of the above identified subspecies 
assuming the anatomy is similar to those of the 
snails of the shells described by Pilsbry. 

Shell: Amber-colored, translucent, very 
fragile, imperforate, broadly ovate, composed of 
up to three whorls separated by a sharply in- 
cised suture (Fig. 1, A, B). Range in height of 
eight shells of this series is 13.3 mm to 8.2 mm; 
range in width 7.0 mm to 4.7 mm. Dimensions 
and ratios of dimensions of shells are recorded 
in Table 1. A knoblike nuclear whorl tops the 
short spire; whorls increase rapidly in size 
resulting in an elongate ultimate whorl. Nuclear 
whorl finely wrinkled, punctate (Fig. 2). 
Irregularly-spaced longitudinal striations fine 
on lower part of nuclear whorl increase grad- 
ually, becoming coarser on ultimate whorl. 
Aperture broadly ovate, occupies about 80% to 



85% of entire height of shell. Peristome sharply 
edged; thin callus on ultimate whorl above the 
aperture; whitish columella follows inner border 
of peristome, curves as it disappears into the 
ultimate whorl. 

Dimensions of the holotype and paratypes also 
are recorded in Table 1. The height attained by 
shells of that series is 16.7 mm. The difference 
in height of the two series may be attributable to 
a difference in time of summer when collected. 
The larger, more mature snails may not survive 
later than sometime in July, therefore, those 
from the Seattle site, collected in August, prob- 
ably do not represent maximum size for the 
species. 

Body and Mantle Surfaces: (Fig. 3). Body wall 
cream-white, transparent, irregularly tubercu- 
late. Some individuals sparsely, others more 
darkly, pigmented. Pigmentation of dorsal body 
surface consists of fine (small) black flecks ex- 
tending from anterior end of head to junction of 
mantle and body wall. Mid-dorsally on the head 
black flecks of indistinct bands form an ill- 
defined triangle, narrowing to a band between 
the superior (posterior) tentacles, dividing and 
continuing as a double band mid-dorsally the 
length of the body. On either side two bands 
parallel the double median band. Surface of 
superior tentacles flecked. Pigmentation of 
lateral body wall consists of spots of fine (small) 
flecks forming an indistinctly outlined band. 

Genital aperture, approximately 1.0 mm in 
length, surrounded by a white, tumid lip, is 
situated on anterior right-hand side of body. On 
either side a pedal groove, continuous from 
labial palp to posterior tip of body, separates 
foot from lateral body wall; pedal groove paral- 
leled by a less pronounced suprapedal groove. 



Vol. 99 (4) 





October 31, 1985 



THE NAUTILUS 135 



B 






FIG. 1. Shells of Oxyloma nuttalliana chasmodes Pilsbry: 
A, B, Locality, Seattle, Washington, (Height, 11.4 mm); C, 
D, Paratype (Height, 12.8 mm); E, F, Holotype (Height, 
16.5 mm). 




k 



FIG. 2. Scanning-electron-photomicrograph of nuclear 
whorl of Oxyloma nuttalliana chasmodes Pilsbry. 
















•*& 




FIG. 3. Pigmentation patterns of head, body and mantle of 
Oxyloma nuttalliana chasmodes Pilsbry. 



Shallow, vertical grooves incise the suprapedal 
and pedal grooves and body wall producing 
shallow scallops along margin of body wall 
especially when animal is in a somewhat con- 
tracted state. Sole of foot cream-white, un- 
pigmented. 

Mantle collar flecked with black pigment. 
Along anterior margin of mantle are patches of 
black pigment from which streaks extend poste- 
riorly becoming diffuse over the mantle surface. 
In mature snails these streaks are concentrated 
between pulmonary blood vessels. The main pul- 
monary vessel is variably outlined by the pig- 
ment (Fig. 3). Flecks are scattered over the light 
yellow nephridium. An elongate black blob on 
the left anterior nephridial margin is followed by 



136 THE NAUTILUS 



October 31, 1985 



Vol. 99(4) 



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Vol. 99(4) 



October 31, 1985 



THE NAUTILUS 137 



lesser patches or by a narrow, indistinct or a 
continuous band along the nephridial margin. 
Other patches of pigment are scattered over the 
left-hand side of the mantle. 

Reproductive Organs: (Fig. 4). Albumin gland 
light cream-colored, triangular, composed of 
fine acini, enclosed within a thin, transparent, 
unpigmented sheath. Seminal vesicle elongate, 
subequally bilobed terminally, enclosed within a 
thin, transparent sheath speckled with black 
pigment. The darkly pigmented hermaphroditic 
duct joins the seminal vesicle to form the fertili- 
zation sac from which diverge the oviduct and 
the sperm duct which leads into the prostate 
gland. Prostate gland light cream-colored, 
ovate, elongate, enclosed by a thin, transparent, 
non-pigmented or sparsely flecked sheath, com- 
posed of acini which are coarser than those of 
the albumin gland. Vas deferens slightly pep- 
pered with black pigment. As the vas deferens 
approaches the penis from the prostate gland it 
follows the penis along its dorsal surface and 
enters the penial sheath distally. Within the 
penial sheath the vas deferens becomes the 
coiled epiphallus, enters the penis subterminally 
resulting in a penial appendage. Penial append- 
age elongate, digitiform and recurved. Penis 
coiled in a half turn before giving off appendage 
(Fig. 4, A, B). Penial retractor muscle, a white 
band, pierces the penial sheath at its distal end 
to be attached to the epiphallus. 

Vagina, longer than the penis, straight and 
non-pigmented. Spermatheca large, inflated. 
Spermathecal duct transparent, wide, stout as it 
approaches and enters the vagina terminally. 
Oviduct highly convoluted, enters the vagina 
distally, ventral to the spermathecal duct (Fig. 
4, C). 

Radula and Jaw: The radula is composed of 
many rows of teeth and numerous teeth to a 
row. The number of rows in four radulae ex- 
amined ranges from 76-86. The ratios of margi- 
nals to laterals approaches 1:4 and 1:5 (Table 2) 
which is within the range of other species of 
Oxyloma as reported: 0. retusa (Lea) (Franzen, 
1963, Table II, p. 89), 0. salleana (Pfeiffer) 
(Franzen, 1966, Table II, p. 65), 0. haydeni (W. 
G. Binney) (Franzen, 1964, Table II, p. 78) and 
0. deprimida Franzen (Franzen, 1973, Table 2, 
p. 71). 

Structural details of individual teeth resemble 



PA PS p 




EP P 



PRM 



EP PA 




B 



PRM 



SPD 




HD 



FIG. 4. Drawings of genital organs of Oxyloma mittatliana 
chasmodes Pilsbry. A, B, P, penis; PA, penial appendage; 
EP, epiphallus (shown inside of penis sheath cut open); PRM, 
penial retractor muscle. C, P, penis; VD, vas deferens; PRM, 
penial retractor muscle; SPD, spermathecal duct; SP, sper- 
matheca; HD, hermaphroditic duct; VA, vagina; OD, 
oviduct; PG, prostate gland; FS, fertilization sac; SV, 
seminal vesicle; AG, albumin gland. 



138 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



TABLE 2. Formulae of representative rows of teeth of 
Oryloma nuttalliana chasmodes Pilsbry from four 
specimens; Field no. DSF 554, Seattle, Washington. 



si Lde 


No. of Rows 
of Teeth 


Row 


M 


L ( 


: l 


M 


1 


80 




31 


30 


- 6 - 


- 6 - 


31 








32 


31 


- 6 - 


- 6 - 


31 


2 


82 




23 
24 

30 


35 


- 8 - 


9 - 
- 9 - 


34 
36 


3 


SI, 




25 

28 


36 
38 


- 8 - 

- 7 - 






4 


76 




27 


25 


- 5 - 


- 6 - 


25 




LJ 1 



5-L-M 26-L-M 




B 

FIG. 5. A, Representative radula teeth of Oxyloma nuttaU 

Inn,, i rhaswoilrs Pilsbr\ (', centra! tooth; 1 I.I., 1-1 left 
lateral; 7-L-L, 7th left lateral; 1-L-M, 1st left marginal; 
5-L-M, 5th left marginal; 26-L-M, 26th left marginal. B, A 
jaw of Oxyloma nuttalliana chasmodes Pilsbry. 



those of the genus in general (Fig. 5, A). The 
central tooth has a broad basal plate which has a 
pointed or bluntly rounded projection on either 
side. The pointed mesocone, somewhat variable 
in length, does not extend to the lower margin 
of the basal plate. A shorter, pointed ectocone 
Hanks the mesocone on either side. The laterals 
have a large, pointed mesocone which, also, is 
not as long as the basal plate. The single ecto- 
cone, sometimes divided into two -especially of 
the more lateral teeth -is pointed; a short, 
pointed endocone may be present. The margi- 
nals, smaller than the laterals, have a long, 
slender basal plate which is characteristic of the 
is Oxyloma (Quick, 1933:296, Fig. 1, 



Oxyloma (Succinea) pfeifferi "Rossm."). Of the 
cusps of the marginals the mesocone is the larg- 
est, the endocone shorter and pointed. The ec- 
tocone of the two, sometimes only the first and 
also the third, medial-most marginals is divided 
into two unequal cusps of which the lateral-most 
is the larger. Rarely a marginal whose ectocone 
is divided into three cusps appears between two 
with the ectocone divided into two cusps. The 
ectocone of the more lateral marginals is divided 
into three and as many as six cusps of which the 
outermost is curved and the largest. 

The features of the amber-colored jaw are 
typical of the genus (Fig. 5 B). A prominent 
median fold projects anteriorly and is flanked on 
either side by a broadly rounded fold. Poste- 
riorly the margin of the collar has a fold on 
either side of a median indentation. 

I have not sufficiently examined shells and 
soft anatomy of succineas identified as Oxyloma 
nuttalliana (Lea) to determine whether or no1 
0. nuttalliana chasmodes Pilsbry should be a 
subspecies or a valid species. Further studies, 
including geographic distribution and habitats, 
are needed to make such a determination. 

Acknowledgments 

National Science Foundation Grants-in-Aid 
No's. NSF GI8000 and NSF GB2715 provided 
laboratory equipment. Scanning-electron photo- 
micrographs were the courtesy of Dr. M. J. 
Nadakavukaren, Illinois State University, 
Normal Illinois, Dr. George M. Davis, Academy 
of Natural Sciences of Philadelphia, Philadel- 
phia, Pennsylvania, lent shells of the museum 
collection. Dr. A. Byron Leonard, University of 
Kansas, Lawrence, Kansas, read the manu- 
script and offered helpful suggestions. 

LITERATURE CITED 
Franzen, Dorothea S. 1963. Variations in the Anatomy of 

the Succineid Gastropod Oxyloma retusa. The Nautilus 

76(3):82-95, tables 1-2, figs. 1-4. 
1964. Anatomy of the Succineid Gastropod 

Oxyloma haydeni. The Nautilus 77(3):73-81, tables 1-2. 

fig. 1. 

1966. Anatomy of the Succineid Gastropod 



Oxyloma sallvana (Pfeiffer). 1'h, Nautilus 80(2):59-69, 
tables 1-2, figs. 1-3. 

1973. Oxyloma licprimiiUi. A New Species of 



Succineidae(Pulmonata). The Nautilus %7@):66-71, tables 

1-3, figs. 1-4. 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 139 



Pilsbry, Henry A. 1948. Land MoUusca of North America 
(North of Mexico). Acad. Nat. Sci. Philadelphia Monograph 
No. 3, vol. 2, pt. 2: pp. i-xlvii + 521-1113. 585 figs. 



Quick. H. E. 1933. The Anatomy of British Succineae. Proc. 
Mala. Sac. London 20(6, Nov.):295-318, pi. 23-25, figs. 
1-18, Tables I-V. 



PSEUDOTORINIA BULLISI, NEW SPECIES (GASTROPODA: 
ARCHITECTONICIDAE) FROM SUBTROPICAL WESTERN ATLANTIC 



Riidiger Bieler 

Division of Mollusks 

National Museum of Natural History 

Smithsonian Institution 

Washington, D.C. 20560 

The species we describe herein was first men- 
tioned by Merrill (1970), in his unpublished study 
of the Atlantic Architectonicidae. The senior 
author is completing a study of the Indo-Pacific 
species of Architectonicidae and needs an avail- 
able description of this species for purposes of 
comparison with some closely related species of 
the Indo-Pacific. We place the species in the 
genus Pseudotorinia Sacco, 1892, based on the 
revision by Bieler (1985). Terminology of shell 
sculpture follows Bayer (1940:224) and Bieler 
(1984:455). 



Pseudotorinia bullisi, new species 
Fig. 1 
Description: Shell small, solid, with a max- 
imum diameter of 10.2 mm and height 3.6 mm, 
upper surface flattened, with only a weakly 
channeled suture; base slightly convex and 
obliquely angled to about halfway, then flat- 
tened on to the umbilicus. Color whitish, ir- 
regularly mottled with light-brown, or uniform 
light-cream. Whorls up to 4Vs, strongly angu- 
lated, tightly coiled and joined at the midline of 
the prominent peripheral cord. Protoconch 
small, smooth, anastrophic, and after emerging, 
continuing for about 1 k whorl, then forming a 
distinct varix, with 2 whorls of the emerging 
protoconch clearly visible from dorsal view. Dor- 
sal spiral sculpture is composed of very strong 
subsutural and peripheral cords, and a promi- 
nent penultimate cord between, with shallow ex- 
cavations on either side; 2 minor cords and (on 
larger specimens) several threads lie within the 



Arthur S. Merrill 
and Kenneth J. Boss 

Department of Mollusks 

Museum of Comparative Zoology 

Harvard University 

Cambridge, MA 02138 

excavation between the sutural and penultimate 
cord. Basal spiral sculpture includes an in- 
fraperipheral cord with a deep narrow excava- 
tion between it and the peripheral cord, a very 
strong cord (basal keel) centrally located at the 
angulation where the base flattens, a strong 
crenulated umbilical cord, and 2 weaker cords 
between the central cord and the umbilical cord; 
approximately 8 weak threads are formed on 
the base between the infraperipheral cord and 
the basal keel. Numerous faint axial lines cut the 
entire surface of the shell. All cords are strongly 
elevated, and evenly nodulose. Umbilicus widely 
open (39-46% of the shell diameter), the walls 
marked with scaly axial lines. Aperture angular, 
the peripheral edge slightly bulging and the 
sides straight. Operculum and animal unknown. 
Dimensions: 









Teleo- 




Proto- 




Maximum 




conch 


Umbilical 


conch 




diameter 


llri : .],t 


whorls 


width 


diameter 


Holotype 


10.2 mm 


3.6 mm 


4Vs 


4.1 mm 


0.62 mm 


Paratype 1 


4.0 


1.2 


2 .- 


1.8 


0.62 


Paratype 2 


4.9 


1.6 


2'- 


2 2 


0.62 


Paratype 3 


4.2 


1.6 


2% 


1.6 


0.62 



Remarks: The shell characters of Pseudotori- 
nia bullisi place it near P. numulus (Barnard, 
1963) of the Indian Ocean (fig. 2, first published 
photograph of that species); P. numulus has a 
larger protoconch (0.70-0.76 mm), and there are 
3-5 well-developed cords below the infraperi- 
pheral which are lacking or reduced to occa- 
sional threads in P. bullisi. 

In the Atlantic, the Pseudotorinia architae 
(Costa, 1841) complex displays similar shell 



140 THE NAUTILUS 



October 31, 1985 



Vol. 99(4) 




FIGS. 1-3. 1, Pseudotorinia buliisi n. sp. (holotype USNM 819925; greatest diameter 10.2 mm). 2, Psevdotorinia numulns 
(holotype of Heliacus numulus Barnard, 1963; SAM A9125; greatest diameter 4.5 mm). 3, Pseudotorinia retifera (holotype of 
Discohelix (Discosolis) retifera Dall, 1892; USNM 83695; greatest diameter 4.4 mm). 



characters (fig. 3 shows the type of P. retifera 
(Dall, 1892), a Pliocene representative of that 
group from Western Atlantic waters). The 
suture is not channeled in P. buliisi as in P. 
retifera, and the major spiral cords are more 
elevated and more coarsely nodulated, with the 
axial markings less prominent. In P. retifera the 
dorsal penultimate cord is closer to the peri- 
pheral cord and not as deeply excavated be- 
tween. As in P. numulus, P. retifera has 3 well- 
developed cords below the infraperipheral which 
are reduced or lacking in P. buliisi. The um- 
bilical cord is stronger in P. retifera, but the 
basal keel is weaker. The upper part of the base 
is more convex in P. retifera, and more obliquely 
angled in P. buliisi. 

Types: Holotype and Paratype 1 of Pseudo- 
torinia buliisi are in the National Museum of 
Natural History, Washington (USNM 819925 



and 500298), and paratypes 2 and 3 in the Muse- 
um of Comparative Zoology at Harvard Univer- 
sity, Cambridge (MCZ 262982). The type locality 
(holotype and paratypes 2 and 3) is RIV Oregon 
station 518, about 90 miles southwest of Pensa- 
cola, Florida (29°23.2'N. Lat.; 88°03.0'W. 
Long.), at a depth of 82 meters. Paratype 1 is 
from the Smithsonian University of Iowa Ex- 
pedition 1918, Barbados station D.3, on a sandy 
bottom off Pelican Island in 137-146 m. 

Range: The four known specimens are from 
off Florida and Barbados in depths of 82-146 m. 

Etymology: Pseudotorinia buliisi is named for 
Mr. Harvey R. Bullis, who formerly headed a 
Bureau of Commercial Fisheries Exploratory 
Base at Pascagoula, Mississippi. Mollusk 
material sent by Mr. Bullis from his exploratory 
missions greatly enhanced Merrill's (1970) study 
of the Atlantic Architectonicidae. 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 141 



Acknowledgments 

We are indebted to Dr. Terrence M. Gosliner, 
formerly at the South African Museum, Cape 
Town, for the loan of the holotype of Heliacus 
numulus, and to Mr. Warren C. Blow, Depart- 
ment of Paleobiology, National Museum of 
Natural History, Washington, for the loan of the 
holotype of Discohelix retifera. Photographs 
were taken by Mr. Victor E. Krantz, National 
Museum of Natural History. 

LITERATURE CITED 
Barnard, K. H. 1963. Contributions to the knowledge of 

South African marine Mollusca. Part 3. Gastropoda: 

Prosobranchiata: Taenioglossa. Annals of the South 

African Museum 47(1):1-199. 37 figs. 
Bayer, C. 1940. Catalogue of the Solariidae in the Rijks- 

museum van Natuurlijke Historie. I. Solarium s.s. 

Zoologische Mededeelingen 22:223-256. 5 figs. 



Bieler, R. 1984. Morphometrische Analyse der Architeo 
tonica maxima - Gruppe im Indo-Pazifik (Mollusca: 
Gastropoda: Architectonicidae). Verhandlungen des 
NaMrvuissenschafUichen Vereins in Hamburg (NFI 27: 
453-492, 8 figs., 7 maps, pis. 1-4. 

1985. Die Gattungen der Architectonicidae 

(Gastropoda: Allogastropoda). Teil 3: Pseudotorinia, 
Nipteraxis, Heliacus, Eosolarium. Archie fur Molt usken- 
kunde 116(1-3): [in press]. 

Dall, W. H. 1892. Contributions to the Tertiary fauna of 
Florida, with especial reference to the Miocene Silex-beds 
of Tampa and the Pliocene beds of the Caloosahatchie 
River, 2.- Streptodont and other gastropods, concluded. 
Transactions of the Wagner Free Institute of Science of 
Philadelphia 3(2):201-458, pis. 13-22, 1 map. 

Merrill, A. S. 1970. The family Architectonicidae (Gastro- 
poda: Mollusca) in the Western and Eastern Atlantic. 
Unpubl. Ph.D. thesis, University of Delaware; 338 pp., 
42 pis. (University Microfilms International, Inc., Ann 
Arbor, Michigan; No. 71-6444). 



A COMMENT ON STROPHITINAE GORDON, 1984 
(UNIONIDAE, BIVALVIA) 

Arthur E. Bogan 

Department of Malacology 

Academy of Natural Sciences 

Philadelphia, PA 19103 



The history of the suprageneric taxonomy of 
unionid bivalves was traced by Heard and 
Guckert (1971) and by Davis and' Fuller (1981). 
Haas (1969a, b) provided the latest comprehen- 
sive supraspecific monograph of the Unionacea 
but his classification was questioned by Heard 
and Guckert (1971) and Davis and Fuller (1981). 
Heard and Guckert (1971:336) noted that 
Strophitus Rafinesque, 1820, is "more correctly 
considered as a single group unlike any other 
subfamily", but included Strophitus in the 
Anodontinae (Heard and Guckert, 1971:340). 
Davis and Fuller (1981) did not discuss 
Strophitus. 

Gordon (1981:58) in discussing the unionids of 
Arkansas created the new tribe Strophitini, for 
Strophitus Rafinesque, 1820. Gordon (1985:8, in 
footnote to Table 1) raised the Strophitini to 
subfamilial status, but omitted any discussion or 
justification for his action. He did not present 
any arguments about the relationships of this 



new subfamily to the other subfamilies in the 
Unionidae. However, neither the taxonomic 
validity nor the method of publication of 
Gordon's name Strophitini or Strophitinae are 
at issue here. 

Gordon was apparently unaware of a previous 
use of Strophitinae. Starobogatov (1970:69, 287) 
erected a new subfamily Strophitinae in the 
family Lampsilidae for Strophitus Rafinesque, 
1820. The following translation of Staroboga- 
tov's (1970:287) justification for his new sub- 
family is provided for those who do not have 
access to the original Russian publication: 
Subfam. Strophitinae Starobogatov. subfam. n. 
The shell has a weakened or rudimentary hinge. The beak 
sculpture consists of lirae (ribbing) which run in almost 
parallel Inn- <>f gruwth and turn abruptlj upward in the 
rear. The marsupial pouches occupy the external half of 
the gills completely. Secondary water tubes during preg- 
nancy bear the young. Each ovisac is divided by transverse 
partitions into a series of chambers. Growth is even, the 
glochidia do not parasitize fish. 



142 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



Therefore, the correct citation of Strophitinae 
(as well as Strophitini, ICZN Article 36) is 
Strophitinae Starobogatov, 1970. 

Acknowledgments 

I thank James Quinn and Robert Robertson 
for reviewing the manuscript and commenting 
on the nomenclature in this paper. Ruth Griffith 
provided the English translation of the Russian 
text on Strophitinae; and Cynthia Bogan typed 
the manuscript. 

LITERATURE CITED 

Davis, G. M. and S. L. H. Fuller. 1981. Genetic relation- 
ships among recent Unionacea (Bivalvia) of North 
America. Malacologia 20(2):2 17-253. 



Gordon, M. E. 1981. Recent Mollusca of Arkansas with 

annotations to systematics and zoogeography. Proc. Ark. 

Acad. Sci. 34(198):58-62. 
1985. Mollusca of Frog Bayou, Arkansas. The 

Nautilus 99(l):6-9. 
Haas, F. 1969a. Superfamilia Unionacea. In: Das Tierreich. 

Berlin, Lieferung 88, pp. i-x, 1-663. 
1969b. [Unionacea], pp. N411-N471, In: R. C. 

Moore (ed.). Treatise on Invertebrate Paleontology, -part 

N. volume 1, Mollusca 6. Bivalves. Geological Society of 

America, University of Kansas Press. 
Heard, W. H. and R. A. Guckert. 1971. A re-evaluation of 

the recent Unionacea (Pelecypoda) of North America. 

Malacologia 10(2):333-355. 
Starobogatov, Ya. I. 1970. [Mollusc fauna and Zoogeograph- 

ical Partitioning of Continental Water Reservoirs of the 

World.] Akademiya Nauk SSSR. Zoologischeskii Instituti 

Nauka. Leningrad 1970, pp. 3-372, 39 fig., 12 tabs. [In 

Russian!. 



DISTRIBUTION OF LAMPSILIS POWELLI (LEA) 
(BIVALVIA: UNIONACEA) 



Mark E. Gordon 

Department of Zoology 
University of Arkansas 
Fayetteville, AR 72701 



ami 



John L. Harris 

Environmental Division 

Arkansas State Highway 

and Transportation Depart. 

Little Rock, AR 72203 



Lampsilis powelli (Lea, 1852) is a rare and 
poorly known freshwater mussel associated 
with the Interior Highlands or Ouachita 
Mountains of western Arkansas. This species 
was not included in Burch (1975). In the three 
published reviews of Arkansas Bivalvia, it was 
synonymized under Actinonaias ligamentina 
(Lamarck) by Call (1895) and overlooked by 
Gordon, et al. (1980) and Gordon (1981). Sub- 
sequently, L. powelli was monographed by 
Johnson (1980) including distributional informa- 
tion based on published accounts and some 
museum material. Examination of museum 
specimens, published accounts, and recent col- 
lecting has enabled us to better delineate the 
known distribution of this species. 

The type locality is the Saline River, here 
restricted to Benton, Saline County, Arkansas. 
In addition to Lea's specimens (USNM 85042), 
topotypes were collected by H. E. Wheeler and 



R. E. Call (UMMZ 91080 and MCZ 5548, respec- 
tively). Outside Arkansas, Call (1887) reported it 
from the Spring River at Baxter Springs, 
Cherokee County, Kansas (MCZ 5550), included 
a brief description, and compared it to 
Actinonaias ligamentina. Scammon (1906) simi- 
larly described a specimen from the Neosho 
River at Oswego, Labette County, Kansas. 
Simpson's (1914) locality information appears to 
be mainly erroneous. Utterback's (1916) and 
Isely's (1925) records (Neosho basin) were based 
on identifications from L. S. Frierson (the White 
River record in Utterback [1917] was a misprint 
for the 1916 account). Particularly notable are 
Isely's comments (p. Ill) in reference to his 
specimens: 
"52. Lampsilis powellii (Lea)- Mr. Hill 
reports this species from the Illinois River and 
has sent me a number of specimens. Frierson 
suggests that Hill's specimens are either 



Vol. 99 (4) 



October 31, 1985 



THE NAUTILUS 143 



powellii or an undescribed species; he 
also places some of them near /,. Hijamentina 
examples of the Neosho as probably powellii." 
Lampsilis rafinesqueana Frierson (1927) was 
described from these Illinois River, Oklahoma, 
specimens. The holotype (female) and a male 
from the Elk River, McDonald County, Missouri 
(probably the "L. poivelli" in Utterback, 1916) 
were illustrated in Frierson (1928). Call's (1887) 
and Scammon's (1906) descriptions for their L. 
powelli specimens are readily identifiable as L. 
niin/isi/iirnini (confirmed by examination of 
Call's voucher, MCZ 5550). The distinctive ray- 
ing of the latter species may be obscured or 
obliterated in older specimens and the shell, par- 
ticularly males, may be easily confused with A. 
ligamentina. Johnson's (1980) L. powelli from 
the Black River, Missouri (MCZ 271445) is an 
unrayed L. radiata siliquoidea (Barnes) (see 
Utterback, 1916: Fig. 103A and B). 

Recently, we have located small populations of 
Lampsilis powelli in the upper Saline and 
Ouachita river basins within the Ouachita Moun- 
tains division of the Interior Highlands of 
Arkansas (Fig. 1). With the exception of the 
previously noted topotypes and a lot in the Ohio 
State University Museum of Zoology (OSUM 
21496: fide Stansbery, 1983), these are the only 
localities for this species which we have been 
able to substantiate. Considerable past habitat 
has been inundated by recent impoundments 
(not shown in Fig. 1) which periodically utilize 
hypolimnetic discharge. One population is 




FIG. 1. Distribution (A) of Lampsilis powelli (Lea) in 
Interior Highlands of Arkansas. 



presently downstream from DeGray Reservoir, 
a multi-level release facility, and several others 
are jeopardized by proposed impoundments. 
With regards to the above and the restricted 
range of L. powelli, some protected status ap- 
pears warranted to ensure the survival of this 
species. 

In concordance with Johnson (1980), the shell 
does resemble L. virescens (Lea), although con- 
vergence of shell characters may mask true 
phylogenetic relationships, and may be confused 
with L. hydiana (Lea), L. radiata siliquoidea, 
and L. teres (Rafinesque). Distinguishing 
characteristics between these species were dis- 
cussed by Johnson (1980). In addition to L. teres, 
occasional specimens of L. hydiana and L. 
radiata siliquoidea may also be totally rayless. 
Generally, the shell of L. powelli is relatively 
thinner and the posterior ridge of males is more 
angular than those of the former species. Lamp- 
silis powelli does sometimes exhibit a super- 
ficially rayed appearance. This is not pige- 
mented periostracum, but a curious serial pro- 
gression of minute pits arranged radially on the 
shell. Johnson (1980) additionally noted a 
resemblance toL. reeveiana (Lea); however, this 
species is not sympatric with L. powelli. 

Acknowledgments 

We would like to thank Wendy K. Welch, S. 
Winters, and Paul J. Polechla for their field 
assistance and Richard I. Johnson (MCZ) and 
James Bailey (UMMZ) for the loan of specimens. 
Partial funding was received from the Arkansas 
Natural Heritage Commission and the Univer- 
sity of Arkansas Foundation, Inc. 

LITERATURE CITED 
Burch, J. B. 1975. Freshwater unionacean clams (Mollusca: 

Pelecypoda) of North America. Malacological Publications, 

Hamburg, Michigan. 204 pp. 
Call, R. E. 1887. Sixth contribution to a knowledge of the 

fresh-water Mollusca of Kansas. Bull. Washburn Coll. 

Lab. Nat. Hist. 2:11-25. 

_ 1895. A study of the Unionidae of Arkansas, 

with incidental references to their distribution in the 

Mississippi valley. Trans. Acad.. Sci. St. Louis 7:1-65. 
Frierson, L. S. 1927. A classified and annotated check list of 

the North American naiades. Baylor University Press, 

Waco. Ill pp. 
1928. Illustrations of Unionidae. The Nautilus 

41:138-139. 
Gordon, M. E. 1981. Recent Mollusca of Arkansas with 



144 THE NAUTILUS 



October 31, 1985 



Vol. 99 (4) 



annotations to systematic* and zoogeography. Proc. Ark. 

Acad. Sr, 34:58-62. 
Cordon. M. E.. L. R. Kraemer, and A. V. Brown. 1980. 

Unionacea of Arkansas: historical review, checklist, and 

observations on distributional patterns. Bull. Amer. 

Malacol. Union 797.9:31-37. 
Isely, F. B. 1925. The fresh-water mussel fauna of eastern 

Oklahoma. Proc. Okla. Acad. Set. 4:43-118. 
Johnson, R. I. 198D. Zoogeography of the North American 

Unionacea (Mollusca: Bivalvia) north of the maximum 

Pleistocene glaciation. Bull. Mus. Comp. Zool. 149:77-189. 
Lea, I. 1852. New fresh water and land shells. Trans. Amer. 

Philos. Soc. 10:253-294. 
Scammon, R. E. 1906. The Unioniadae of Kansas, pt. 1. 

Univ. Kans. Sci. Bull. 3:279-373. 



Simpson, C. T. 1914. A descriptive catalogue of the naiades, 
nr tin pearly fresh iruter mussel. Bryant Walker, Detroit 
1540 pp. 

Stansbery, D. H. 1983. Some sources of nomenclaturial and 
systematic problems in unionid mussels. Pages 46-62 in A. 
C. Miller, compiler. Report of freshwater mussels work- 
shop, 26-27 October 1982. U. S. Army Engineer Water- 
ways Experiment Station, Environmental Laboratory, 
Yicksburg. 

Utterback, W. I. 1915-1916. The naiades of Missouri. Amer. 
Midi. Nat. 4:41-53, 97-152, 181-204, 244-273, 311-327, 
339-354, 387-400, 432-464. 

1917. Naiadgeograph\ of Missouri Amei Midi 

Nat. 5:26-30. 



Announcing a New 

MONOGRAPHS OF MARINE MOLLUSCA 

Taxonomic revisions of the living and 
Tertiary marine Mollusca of the world 

Edited By R. Tucker Abbott 

ARCHAEOGASTROPOD BIOLOGY AND THE SYSTEMATICS OF THE GENUS 
TRICOLIA (TROCHACEA: TRICOLIIDAE) IN THE INDO-WEST-PACIFIC 

Robert Robertson 

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