—

5BM 1033S

Zoology Series|="*

wy

THE

NATURAL
HISTORY
MUSEUM

VOLUME 66 NUMBER2 30 NOVEMBER 2000

The Bulletin of The Natural History Museum (formerly: Bulletin of the British Museum
(Natural History) ), instituted in 1949, is issued in four scientific series, Botany,
Entomology, Geology (incorporating Mineralogy) and Zoology.

The Zoology Series is edited in the Museum’s Department of Zoology
Keeper of Zoology Prof P.S. Rainbow
Editor of Bulletin: Dr B.T. Clarke

Papers in the Bulletin are primarily the results of research carried out on the unique and ever-

growing collections of the Museum, both by the scientific staff and by specialists from elsewhere

who make use of the Museum’s resources. Many of the papers are works of reference that will remain
indispensable for years to come. All papers submitted for publication are subjected to external peer review for
acceptance.

A volume contains about 160 pages, made up by two numbers, published in the Spring and Autumn.
Subscriptions may be placed for one or more of the series on an annual basis. Individual numbers and back
numbers can be purchased and a Bulletin catalogue, by series, is available. Orders and enquiries should be
sent to:

Intercept Ltd.

P.O. Box 716

Andover

Hampshire SP10 1YG

Telephone: (01264) 334748

Fax: (01264) 334058

Email: intercept @ andover.co.uk
Internet: http://www.intercept.co.uk

Claims for non-receipt of issues of the Bulletin will be met free of charge if received by the Publisher within 6
months for the UK, and 9 months for the rest of the world.

World List abbreviation: Bull. nat. Hist. Mus. Lond. (Zool.)

© The Natural History Museum, 2000

Zoology Series
ISSN 0968-0470 Vol. 66, No. 2, pp. 109-170

The Natural History Museum
Cromwell Road
London SW7 5BD Issued 30 November 2000

Typeset by Ann Buchan (Typesetters), Middlesex
Printed in Great Britain by Henry Ling Ltd., at the Dorset Press, Dorchester, Dorset

Bull. nat. Hist. Mus. Lond. (Zool.) 66(2): 109-146 Issued 30 November 2000

The shallow-water marine Mollusca of the -——:

THE NATURAL
Kstero Elefantes and Laguna San Rafael, | "!S'ORY “useUly
southern Chile NOV 2000

=D

ne
i.6

Fe

m4 x

DAVID G. REID
Department of Zoology, The Natural History Museum, London SW7 5BD, U.K. E-mail: dgr@nhm.ac.uk

CECILIA OSORIO

Departamento de Ciencias Ecolégicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425,
Casilla 653, Santiago, Chile. E-mail: cosorio@uchile.cl

SYNOPSIS. Taxonomically, the Mollusca of southern Chile are moderately well known, but the literature is scattered, there is
little information on their habitats, and distributional records are scarce for the Chilean archipelago lying between Isla Chiloé and
Tierra del Fuego. In 1998 a survey was made of the marine biodiversity of the Laguna San Rafael National Park and an area of
the Chonos Archipelago immediately to the north (approximately 46°S). The Laguna consists of a basin of low salinity, strongly
influenced by glacial meltwater, and the Estero Elefantes is a complex fjord system with both brackish and fully marine
environments, including sheltered bays and exposed coasts. Collections of molluscs were made at 26 stations, from intertidal
habitats, kelp plants and by dredging from depths of up to 15 m. A total of 62 species was recorded, consisting of 9
Polyplacophora, 33 Gastropoda and 20 Bivalvia. In order to facilitate future studies in the region, these are briefly described and
all the shelled species illustrated (12 of these photographed for the first time). Notes are given on habitats, depth and salinity, and
geographical ranges are reviewed. Biogeographically, the area lies at the poorly known southern extreme of the transitional zone
between the Magellanic and Peruvian faunal provinces. As a result, 27% of the species records are extensions to the known
ranges, representing northern limits of Magellanic forms and southern limits of Peruvian ones. Of the 62 species found, 48% could
be classed as Magellanic (found in the transitional zone and southwards) and 8% as Peruvian (found in the transitional zone and

northwards), while the remainder occurred in both provinces.

INTRODUCTION

The archipelago or fjordland of southern Chile is a remote and
relatively inaccessible area where little marine research has previ-
ously been carried out. In the heart of the fjordland (at a latitude of
46°S) lies the Laguna San Rafael National Park, a protected area of
1.7 million hectares. In recognition of its importance as a wilderness
area covering a wide range of habitat types, with no significant
human impact, the park has been declared a UNESCO Biosphere
Reserve. Knowledge of the biodiversity of the area, and in particular
that of the marine habitats, remains poor. Therefore, in 1996 a
biodiversity research programme was initiated as a collaboration
between the administrative authority of Chilean protected areas, the
Corporacion Nacional Forestal (CONAP), the youth development
charity Raleigh International, the Museo Nacional de Historia Natu-
ral in Santiago, the Natural History Museum in London and the
World Conservation Monitoring Centre in Cambridge. This report
describes the results of the initial survey in 1998 of the marine
molluscs of the Laguna San Rafael and southern Estero Elefantes
that lie within the park, and an area of the Estero Elefantes in the
vicinity of Isla Traiguén immediately to the north of the present park
boundary. A preliminary report on the general marine survey of this
area has been prepared by Paterson et al. (in press).

Dell (1971) has outlined the history of malacological investiga-
tions in southern Chile, and only a brief account will be repeated
here. Owing to its strategic importance, the Magellan Strait was the
object of several British surveys by H.M.S. ‘Beagle’ and ‘Adven-
ture’ during 1826 to 1830, from which the Mollusca were described
by King & Broderip (1832). Although this work is scarce and not
illustrated, it nevertheless contains the first descriptions of many of

© The Natural History Museum, 2000

the common shallow-water species of the Magellanic region. From
about 1822 to 1831 the notable collector Hugh Cuming was based in
Chile, where he amassed a great collection which was eventually
acquired by the British Museum. This material was the source of
many of the new species described by Sowerby (1833a, b, 1834,
1835, 1838, 1840) and by Reeve, later illustrated in Reeve’s
Conchologia Iconica (1843-1878). The largest single work on the
Mollusca of South America was d’Orbigny’s monumental Voyage
dans l’Amérique Méridionale (1834-1847), based on the results of
his own extensive travels in the southern part of the continent.
Malacological knowledge of Chile was further advanced by the
collections of Gay, described by Hupé (1854), and by the arrival in
Santiago in 1851 of Philippi. As a result, by the middle of the
nineteenth century the molluscan fauna of southern South America
was remarkably well known.

Towards the end of the nineteenth and in the early twentieth
century a number of important expeditions continued the biological
survey of the Magellanic region and dredging activities revealed
more of the subtidal fauna. Molluscs from the ‘Alert’ expedition
were described by E. A. Smith (1881), those from the French
Mission to Cape Horn by Mabille & Rochebrune (1889), from
Swedish and German expeditions by Strebel (1904-1907) and from
the ‘Discovery’ cruises by Powell (1951) and Dell (1964). Two later
expeditions are the source of most of the little existing knowledge of
the fauna of the fjordland between Puerto Montt and the Magellan
Strait. First was the Lund University Chile Expedition which made
extensive collections in the vicinity of Puerto Montt and Isla Chiloé
(41-43°S) during 1948-1949, and also sampled a few localities
further south in the Chonos Archipelago (44-46°S) and Magellan
Strait (52-54°S). Important taxonomic accounts of the Poly-
placophora (Leloup, 1956), Cephalopoda (Thore, 1959), Bivalvia

110

(Soot-Ryen, 1959) and Lamellariacea and Opisthobranchia (Marcus,
1959) were produced, but no report on the Gastropoda appeared
(although some of the new records were published by Brattstrom &
Johanssen, 1983). The second was the Royal Society Expedition to
Southern Chile in 1958-1959. Again collections were made around
Isla Chiloé, and also at Isla Wellington (49°S) and to the south of
Tierra del Fuego at Isla Navarino (55°S). The Mollusca from this
expedition were described by Dell (1971). Although Marincovich’s
(1973) study of the intertidal molluscs of Iquique relates to an area
in the north of Chile (20°S), it is a useful account of the more
common Peruvian species, some of which extend to the southern
part of the country; it is also unique among all previous reports in
being comprehensively illustrated. Recently, an extensive dredging
programme has been carried out in the Beagle Channel (55°S)
(Linse, 1997). A number of useful catalogues have appeared: of the
molluscs of Argentinian Patagonia (Carcelles, 1950); of the mol-
luscs of the Magellanic region (Carcelles & Williamson, 1951; and
anotable series of 14 papers by Castellanos and others, 1988-1993);
of the bivalves of Chile (Osorio & Bahamonde, 1970); of the
bivalves of the entire eastern Pacific Ocean (Bernard, 1983) and of
the Sacoglossa and Nudibranchia of Chile (Schrédl, 1996).

Later in the twentieth century the production of faunistic works
declined and emphasis shifted towards monographic revisions of
taxonomic groups at a regional or wider level. Among those that
have included Chilean species are monographs of Chiton (Bullock,
1988), other polyplacophoran families (Kaas & Van Belle, 1985—
1994), Nacellidae (Powell, 1973), Fissurella (McLean, 1984),
rissoiform gastropods (Ponder & Worsfold, 1994), Acanthina (Wu,
1985), Xymenopsis (Pastorino & Harasewych, 2000), Volutidae
(Weaver & duPont, 1970), Protobranchia (Villarroel & Stuardo,
1998), Mytilidae (Soot-Ryen, 1955), Chlamys (Waloszek, 1984)
and Teredinidae (Turner, 1966).

In conclusion, therefore, there is an impressive array of literature
available for the identification of the molluscs of southern Chile.
Nevertheless, this literature is difficult for the non-specialist to use,
for it is widely scattered and most of the potentially useful faunistic
reports and catalogues are not illustrated, or only inadequately so.
There are also deficiencies in geographical coverage, for the major-
ity of collecting effort has been expended on the Magellan Strait,
Tierra del Fuego and the Patagonian Shelf in the south, and to a
lesser extent on Isla Chiloé and the central region of Chile. Conse-
quently, geographical ranges are poorly known (Brattstrom &
Johanssen, 1983; Schrodl, 1997). Furthermore, this inadequate sam-
pling makes it difficult to evaluate cases of geographical variation as
either clines, allopatric subspecies or partially sympatric sibling
species (examples include Chiton magnificus, Nacella magellanica,
Scurria ceciliana, Acanthina monodon, Malletia magellanica,
Felaniella inconspicua and Carditella tegulata). With the exception
of commercial species, anatomical and genetic work on molluscs of
the region has only just begun. There are already several cases of
developmental and radular studies that have distinguished species
with closely similar or identical shells (e.g. Clench & Turner, 1964,
on Adelomelon and Odontocymbiola; Gallardo, 1979, on Crepidula),
and more such examples can be anticipated as detailed investiga-
tions by local workers continue. Some Magellanic molluscs show
confusing variability in shell characters, and numerous nominal
species have been described. Among the bivalves, examples include
the genera Mulinia and Zygochlamys; in the latter case availability
of an enormous series of shells has led Waloszek (1984) to
synonymize several poorly defined species in one variable taxon. In
the gastropod genera Acanthina, Trophon, Xymenopsis and
Pareuthria shell variability may be connected with local adaptation
facilitated by the nonplanktonic development that is common at high

D.G. REID AND C. OSORIO

latitudes, or perhaps by ecophenotypic effects. Almost three dec-
ades after Dell’s (1971) review of the state of systematic malacology
in Chile, it remains true that these confusing taxa are, in his words,
‘outstanding examples of groups demanding modern treatment by
workers on the spot’.

A review of ecological research on molluscs in southern Chile is
beyond our scope here. Suffice it to say that distribution and life
history of the several commercially important species have received
most attention, as reviewed by Osorio, Atria & Mann (1979).
Marine molluscs are an important resource in Chile, and intertidal
and shallow-water species are widely collected by artisanal fisher-
men (‘divers-mariscadores’ and ‘recolectores de orilla’). National
Statistics for 1997 indicate that 7554 fishermen extracted 93269
tonnes of molluscs (Servicio Nacional de Pesca, 1998). Examples of
recent field studies on commercial species include work on
Concholepas concholepas (Castilla & Duran, 1985; Moreno, Reyes
& Asuncio, 1993), Choromytilus chorus (Navarro, 1988; Moreno,
1995), Ensis macha, Tagelus dombeii and Venus antiqua (Clasing,
Brey, Stead, Navarro & Asencio, 1994; Urban, 1994, 1996; Urban &
Tesch, 1996). Some of the more common intertidal molluscs have
been mentioned in studies of zonation and community structure
(Jara & Moreno, 1984; Alvarado & Castilla, 1996), including a
series of investigations on the influence of human predation on the
organization of intertidal communities (Moreno & Jaramillo, 1983;
Duran, Moreno, Lunecke & Lepez, 1986; Castilla & Oliva, 1987). In
general, however, field research has been concentrated on the central
Chilean coast and around Isla Chiloé (Ramorino, 1968; Brattstr6m,
1990; Santelices, 1991), together with a few studies in the Magellan
Strait and Beagle Channel (Guzman, 1978; Miranda & Acufia,
1979; Ojeda & Santelices, 1984; Castilla, 1985; Benedetti-Cecchi &
Cinelli, 1997; Linse, 1997; Linse & Brandt, 1998). To our know-
ledge, there has been but one previous report on marine ecology
within the Laguna San Rafael National Park, an account of the
impoverished brackish-water ecosystem of the Laguna itself (Dav-
enport etal., 1995) that mentioned only two molluscs. The taxonomic
reports of the exploratory cruises mentioned earlier did mostly
include depth ranges and habitat notes for the species encountered.

Such, then, is the status of research on molluscs in southern Chile.
With this in mind, we have the following objectives in the present
survey. To facilitate future marine ecological work in this neglected
part of southern Chile we briefly describe the 62 species discovered
during the exploration of the Laguna San Rafael National Park and
adjacent area, and clearly illustrate the 59 species with external
shells (in 12 cases these are the first photographic illustrations of the
species). We give notes on habitats and station lists; of interest here
is the gradient of reduced salinity towards the San Rafael Glacier,
and the differential penetration of brackish water by the species. As
a guide to the scattered taxonomic literature we give abbreviated
synonymies, and point out those taxa requiring systematic revision.
The geographical range of each species is critically reviewed, based
on literature records and museum collections. Since the study area
lies within such a poorly studied region of the Chilean coast, and in
the zone of transition between Magellanic and Peruvian faunal
provinces, many of our records represent significant range exten-
sions.

THE ENVIRONMENTAL SETTING AND
MOLLUSCAN ASSOCIATIONS

The fjordland of southern Chile is formed from sunken ranges of
coastal mountains. Within this area the fjord system of the Laguna

MOLLUSCA OF SOUTHERN CHILE

San Rafael and Estero Elefantes is situated at a latitude of 46°S,
between the Chonos Archipelago and Taitao Peninsula to the west,
and the Andean Cordillera to the east. Immediately to the south east
lies the extensive San Valentin Icefield, and from this the San Rafael
Glacier descends to sea level, calving directly into the Laguna. This
is an enclosed body of water up to 15 km in diameter, cut off from the
open ocean of the Golfo San Esteban by a low-lying marshy
moraine. The only outlet from the Laguna is a narrow channel to the
north, the Rio Témpanos, that connects with the Golfo Elefantes at
the head of the fjord system. The Golfo in turn is delimited at its
northern end from the main Estero Elefantes by a series of spits and
islets. Beyond these, the main fjord varies in width from 3 to 10 km
and is fed by several river systems from the mountains to the east,
while to the north and west it eventually connects with the open sea
through a complex system of channels between the large islands of
the Chonos Archipelago. Rainfall in the region is heavy throughout
the year, with up to 4000 mm annually (Viviani, 1979; Davenport et
al., 1995), and both freshwater runoff and glacial meltwater have a
strong local influence, lowering the seawater salinity in the vicinity
of the numerous rivers and streams. Mean monthly temperature
varies between about 5 and 15°C (Viviani, 1979). The area covered
by our survey extends from the Laguna San Rafael to Isla Traiguén,
a distance of 120 km. As a result of the physical configuration of the
fjord system, three somewhat distinct regions can be distinguished:
the Laguna San Rafael, the Golfo Elefantes and the Estero Elefantes
(Figure 1). A general description of physical features and marine
zonation has been provided by Paterson et al. (in press), and here
only a short account of the main habitats and molluscan assemblages
will be given.

The Laguna San Rafael (technically an estuarine ob) is 80-250 m
deep and contains icebergs from the glacier. The shoreline is mainly of
rocks and gravel (stations 29, 30; Table 1), moderately sheltered from
wave action except in the immediate vicinity of the glacier where
waves are produced by calving icebergs. On the shallower and more
sheltered northeastern shore there is development of mudflats and
some salt marsh (station 31). The salinity is low (15—17%c) and the
water column is well mixed (Davenport et al., 1995). Diversity of
algae and invertebrates is low, and only three mollusc species were
found: Mytilus edulis chilensis on boulder shores and in the sublittoral
fringe, Malletia magellanica in soft sediment to a depth of 10 m and
Chilina patagonica on mud among saltmarsh vegetation.

The Golfo Elefantes is characterized by increasing salinity (15—
21%o at surface) and moderate wave action. The shoreline of the
investigated area (station 25) consisted of low conglomerate cliffs,
boulders and semi-sheltered coves of muddy sand. In the littoral
zone the diversity of molluscs was low and just four species were
abundant on hard substrates: Perumytilus purpuratus, Mytilus edulis
chilensis, Nacella magellanica and Siphonaria lessonii. The chiton
Plaxiphora aurata was occasional and Bankia martensi common
boring in driftwood. Valves of Mulinia edulis were found on a beach,
suggesting its presence in shallow-water sediments, and living
Aulacomya atra washed up on the shore indicated a possible subtidal
population. Dredging on a bottom of silt and cobbles revealed a
community dominated by the brachiopod Magellania venosa, and a
sparse but more diverse molluscan fauna of 10 species, including the
predatory whelks Trophon plicatus, Xymenopsis muriciformis,
Pareuthria powelli, and occasional examples of Leptochiton medinae,
Iothia coppingeri, Margarella violacea, Eumetula pulla, Lamellaria
ampla, Malletia magellanica, and Venus antiqua. In the estuary of
the Rio Gualas (station 26) a heavily silted boulder shore was
encrusted with the barnacle Elminius and the green alga Entero-
morpha, and the only living molluscs were Mytilus edulis chilensis,
Perumytilus purpuratus and Plaxiphora aurata.

111

Along the Estero Elefantes (including the southern shores of Isla
Traiguén at its northern end) there were a variety of shore types and
a wide range of wave-exposures. Surface salinity readings ranged
between 5—15%c in estuaries, 15—22%c in the southeastern corner of
the Estero, and elsewhere approached fully marine conditions (27—
33%o). The depth of the Estero varies between 185 and 440 m (with
a sill of 150 m at its northern end), with a halocline at 7-8 m and
deep salinity of 32%o (Pickard, 1971). Only here were strongly
wave-exposed (stations 16, 17) and moderately wave-exposed
(stations 5, 12, 13, 14) rocky shores encountered. A characteristic
zonation was developed on such shores which, from the perspective
of molluscan distributions, can be summarized as follows. At the
upper limit of the eulittoral zone the only mollusc was Nodilittorina
araucana, abundant on rocks partly encrusted with the red alga
Hildenbrandia. Below, in the upper mid eulittoral, a band of small
barnacles (Notochthamalus) was present, sometimes with the algae
Tridaea and Porphyra, and associated molluscs were Nodilittorina
araucana, Siphonaria lessonii and, in the interstices of the barna-
cles, the minute bivalve Lasaea miliaris. The mid and lower
eulittoral was generally dominated by dense beds of Mytilus edulis
chilensis, sometimes together with Perumytilus purpuratus in the
upper part (especially in more sheltered areas or where freshwater
runoff occurred), and (only in the most exposed sites, stations 13,
17) replaced by Aulacomya atra in the lowest eulittoral and
sublittoral fringe. Other characteristic molluscs of the Mytilus belt
included Scurria parasitica attached to the mussels, the predatory
Acanthina monodon and the herbivores Nacella magellanica,
Tegula atra, Fissurella picta and Chiton granosus. On some shores
it appeared that density of these grazers was sufficient to produce a
narrow bare zone devoid of macroalgal cover in the lowest
eulittoral. On exposed shores the rock surfaces in the sublittoral
fringe were encrusted by calcareous red algae, sea urchins were
abundant, and at the top of this zone clumps of the large barnacle
Austromegabalanus were frequent. Mollusca of the sublittoral
fringe included Tegula atra, Argobuccinum pustulosum ranelli-
forme and, in one strongly exposed site (station 16), Concholepas
concholepas. Sheltered microhabitats on these exposed shores,
such as large rock pools and among boulders, harboured a more
diverse range of molluscs including the gastropods Crepidula
dilatata, Trochita trochiformis, Trophon plicatus, Pareuthria
fuscata, P. powelli, Nassarius gayii and Tritonia challengeriana,
and the chitons Chaetopleura peruviana, Ischnochiton stramineus,
Chiton magnificus, Tonicia atrata and T. chilensis.

In bays and inlets of the Estero Elefantes, relatively sheltered
from wave action, both bedrock and boulder shores were dominated
by algae (stations 1, 7, 8, 20). In the upper eulittoral zone filamentous
algae such as the red Bostrychia and green Enteromorpha were
common, together with barnacles, but replaced in the mid and low
eulittoral by large fleshy algae among which the red Mazzaella and
Nothogenia were most abundant. On sheltered shores of this type the
limpets Nacella magellanica, Scurria ceciliana and Siphonaria
lessonii were common on rock surfaces on the upper shore, and
Diloma nigerrima beneath boulders. Lower on these shores a di-
verse assemblage of molluscs occurred among boulders, including
Chiton magnificus, Tonicia atrata, Plaxiphora aurata, Fissurella
nigra, Tegula atra and Acanthina monodon. In areas of low salinity
diversity was reduced (stations 6, 11,21, 22), and on such shores the
molluscan fauna resembled that of corresponding areas of the Golfo
Elefantes. As in the Laguna San Rafael, the only molluscs on
muddy, estuarine shores of lowest salinity (5%o, station 28) were
Mytilus edulis chilensis and Chilina patagonica. Sedimentary shores
with normal salinity were scarce in the Estero Elefantes; only one
sheltered sandy bay was examined (station 1). Here the bivalves

112 D.G. REID AND C. OSORIO

Isla iin
Traiguen

(Pee

study area

AP

patsy Tierra
de] Fuego

Gy

dy

j “Yj
a

2p)

PROSE (i Sepa eet ere

SHEER eae
= |Golfo San Esteban?

V/A \ce sheet
Water Kilometres

[__] Laguna San Rafael National Park boundary 0 30
w E

@ Sampling station

Fig. 1 Survey stations in the Laguna San Rafael, Golfo Elefantes and Estero Elefantes. See Table 1 for coordinates, salinity and temperature data.

MOLLUSCA OF SOUTHERN CHILE

Venus antiqua, Tagelus dombeii and Ensis macha were recorded. On
muddy shores of intermediate salinity the bivalve Mulinia edulis
was frequent (station 20).

Dredging to a depth of 15 m in the Estero Elefantes (stations 1, 9,
14, 22) yielded the most diverse molluscan assemblage encountered
during the entire survey, although numbers of individuals were
always low. The 25 species found were Chiton magnificus, Tonicia
chilensis, Ischnochiton pusio, Leptochiton medinae, Puncturella
conica, Iothia coppingeri, Margarella violacea, Homalopoma
cunninghami, Crepidula dilatata, Xymenopsis muriciformis, X. sub-
nodosus, Pareuthria powelli, Glypteuthria meridionalis, Nassarius
gayii, Adelomelon ancilla, Nucula pisum, Zygochlamys patagonica,
Felaniella inconspicua, Carditella tegulata, Carditopsis flabellum,
Cumingia mutica, Venus antiqua, Retrotapes exalbidus, Tawera
gayi and Hiatella solida.

Much of the shore of the Estero Elefantes was fringed by exten-
sive beds of the giant kelp, Macrocystis pyrifera (sampled at stations
1, 7, 14, 22), growing from depths of about 10 m. In fully marine
situations the laminae of the kelp supported occasional animals of
Nacella mytilina and Flabellina falklandica, while in the holdfasts
were found Fissurella oriens and Aulacomya atra. In conditions of
lower salinity in the southern part of the Estero (station 22) the
species Leptochiton medinae, Plaxiphora aurata, Aulacomya atra
and Hiatella solida were present in the holdfasts.

MATERIAL AND METHODS

The majority of the material was collected during intertidal surveys.
Sampling was by general collecting and by quantitative transect
methods (the results of which will be reported elsewhere). A limited
amount of dredging was carried out in depths of up to 15 m, using a
small handmade apparatus (aperture 70 by 15 cm, with sacking
attached) dragged behind an inflatable boat. Plants of the giant kelp
Macrocystis were pulled up from depths of up to 10 m, and both
holdfasts and laminae examined for molluscs. Searches for
micromolluscs were made by washing dredged and hand-collected
samples of algae in freshwater, and also by close examination of
dredged sediments. Strandlines were searched for dead shells but,
unless otherwise noted, all records refer to living specimens. Collec-
tions and observations were made at a total of 26 stations (Table 1,
Figure 1). Surface salinity and temperature were noted. Material
was preserved in 10% seawater formalin and later transferred to
80% ethanol for storage. Duplicate collections are deposited in both
the Natural History Museum, London (NHM) and the Museo
Nacional de Historia Natural, Santiago (MNHNS). All figured
material is in the NHM; registered specimens carry the prefix
“‘BMNHW’.

In the Systematic Descriptions an abbreviated synonymy is given
for each species. This includes the reference to the original descrip-
tion, one or more references to the most recent taxonomic accounts
that can be consulted for complete synonymies, and significant recent
systematic works. References to the key works on the molluscs of the
region (Leloup, 1956; Soot-Ryen, 1959; Osorio & Bahamonde,
1970; Dell, 1971; Marincovich, 1973) are provided for all species.
Where previous authors have used names other than the ones we
consider to be valid, these are usually synonyms; cases of misidenti-
fication are indicated by ‘not’ followed by the original authority of
the name. The descriptions and dimensions of shells are based on the
present material, with additions from other sources as noted. Dimen-
sions are the greatest linear dimension of the shell, unless otherwise
indicated. All figured specimens are from this survey, except for three

113

species in which the material was too fragmentary, in which case
specimens from the collection of the NHM have been substituted, as
noted. The designation of zones on the shore follows that of Lewis
(1964). Records of geographical distribution refer only to the Chilean
coast, as far south as Cape Horn, including the Magellan Strait, Tierra
del Fuego and the Beagle Channel.

SYSTEMATIC DESCRIPTIONS

Class Polyplacophora

Family LEPTOCHITONIDAE

Leptochiton (Leptochiton) medinae (Plate, 1899)
(Figure 6A, C)

Lepidopleurus medinae Plate, 1899: 82-89, pl. 5, figs 204-206.
Leloup, 1956: 13-15, fig. 2.

Leptochiton medinae — Kaas & Van Belle, 1998: 122.

Leptochiton (Leptochiton) medinae — Kass & Van Belle, 1985: 80—
83, fig. 35, map 37 (synonymy).

DESCRIPTION. Valve area to 10.0 by 6.0 mm, maximum width of
girdle 1.1 mm; valves sculptured with numerous fine rows of small
granules, arranged longitudinally on central areas, radially on lateral
triangles and terminal valves; shell colour cream, often stained with
black deposits; girdle fawn, covered with minute, longitudinally
grooved, conical spicules (Fig. 6C); gills restricted to posterior part
of pallial groove (merobranchial).

HABITAT. Commonly dredged from 3-15 m; in Macrocystis
holdfasts; on cobbles encrusted with calcareous red algae; on peb-
bles and shells lying on silt; at salinities down to 15—22%o. This has
been recorded as a common sublittoral species in 15—30 m (Dell,
1971; Kaas & Van Belle, 1985), and to a depth of 250-300 m
(Leloup, 1956); Dell (1971) also noted one collection from the
intertidal Jridaea zone.

RECORDS. Stations 7, 22, 25. Elsewhere Puerto Montt to Tierra del
Fuego and Magellan Strait (Leloup, 1956; Kaas & Van Belle, 1985).
Range: 40-56°S.

REMARKS. This species should not be confused with the similarly
small, cream species Ischnochiton stramineus, which possesses
slitted insertion plates, quincuncial (not longitudinal) granular sculp-
ture and holobranchial gills.

Family ISCHNOCHITONIDAE

Chaetopleura (Chaetopleura) peruviana (Lamarck, 1819)
(Figure 2A)

Chiton peruvianus Lamarck, 1819: part 1: 321.

Chaetopleura peruviana — Leloup, 1956: 37-40, figs 18-20. Dall,
1971: 218. Marincovich, 1973: 43-44, fig. 101. Ferreira, 1983:
220-221. Kaas & Van Belle, 1998: 142-143.

Chaetopleura (Chaetopleura) peruviana — Kaas & Van Belle, 1987:
62-64, fig 27, map 11 (synonymy).

DESCRIPTION. Valve area to 49 by 22 mm, maximum width of
girdle 11 mm; valves relatively flattened; valves sculptured with
radiating rows of fine pustules; shell colour marbled olive brown,

D.G. REID AND C. OSORIO

114

“AQAINS B1OYS ‘G ays USPprul JUsTOUR ‘Py ‘sjuRTd (sysKoo19D) djoy “yy Sw GT 0} BuIsporp ‘q :sedAq Aaving

Ss
a's 8
a‘s
S él
S 8
S
‘a's
S OI
Ma's Gl
Ss cl
S cl
NS)
S
d Li
Ma's
S
S vl
a's cl
W'S cl
W'S
S
‘a's
S
S
W
‘a's val
(Do)
AQAINS ‘duiay, vas

CCST

yc-Ol

OSC
I€
6
Of

EE5CE

Of

LC

LT

(%)
Aywuryesg sovying

M.CSoEL SLED

M.OL9PSoEL
M.C96 00ovL
M.£86 SEoEL
M.C87 TSo€L
N.ICV PHoEL
M.C69 8H0EL
M.990'LEoEL
M.ED TPotL
M.661 9FoeL
M.CIS PHL
M.VC9'LVoEL
M.989 LPoEL
M.VV0 TVotL
M.CCS 6E0EL
N.SLE OPoEL
M.C86 9VoEL
M.8EL OPEL
N.CLT 8¥0EL
M.€87 LVoEL
M.608 EEL
M.LCO LEoEL
M. TET LEo€L
M.VV6 DEEL
N.660 9EoEL
M.8€C LEoEL

S.109 9.97
S.0CI 07.97
S.C79 61.97
S.€VS LEo9v
S.OLC 8C.9t
S.VET ST9P
SOIT LI9P
S.CCE ECoIV
S.8€1 €C9P
S.SCIC1o9P
S.O€E ChoSP
S.OEC ChoSP
S.196 VSoSP
S.617 SSoSV
$.€98 OS SV
S. ICL 9ES7
S.818 6E0S7
S.SVS 6ES1
S.C91 OvoSV
S.8€0 IpoSV
S.LET SHoSV
$.600 6€S7
S.€1TL 8ESP
S.10@ 8€0S7
S.L16 8E0SP

so]euIpIoo;

jorey ues euNnsey ‘proysry

Jorjey ues eunsey ‘o10ys qN

jersey ueg eunsey ‘oroys

SQULJA[q O19}Sq ‘SOUTT[IN} BIQTe_D ‘Arenisq
SQJULJO[_ OJ[OH ‘uolseAIasqgO ‘|

SOULJI[_ OJ[OH ‘sefeny ory ‘orqopiny Bung jo |
SOJULJI[Y OJ[OH apis MW ‘2A0D

upjenbdn5 oseisq opts AAS ‘JF

sojuRjo[q O19)sq JO IauI09 Ag ‘Avg

SOULJI[Y O19}Sq JO JOUIOD MGS “OUOTT ‘|
SoJULJo[_ O19}Sq ‘dAVITRN ‘ BPs § ‘souagos vung
SdOMI_ Sarpy ose ‘seloy ‘] opis

S9OMID SaLp, Ose ‘seloy “] SPIs AA “IFO

souUuvjo[q O19}sq ‘saynuanyy “| pue uosduirg ‘J useMjoq jouueYyD
sowUuvjo[q O1o}sq ‘soynuiony ‘| pls AN ‘12ST
sowuvjolq O10}sq ‘uosduntg ‘| opis AN NO
SONIC SOIL, OSeg ‘USNSTeI], "[ OPIS AA ‘I2IS]
ugNSIeIL, [| PPIs AS ‘UOoseT]

ugNsIesL, ‘| 2pIs MS “oendy ‘| dn ¢ ‘uspply
ugnstery “| Opis MS “USpPpIIN

ugnsrer] | opis qs ‘Aeg

ugnsIely, ‘| opis qs ‘outer eyung jo q ‘Arg
ugnsrely ‘| opis q ‘Arg

ugnstedy, “[ opis q “Wulod

ugnstely, [ opis q “Ueppry|

ugnsrely, ‘[ apis q ‘Aeg

Aqyeo0T

Te
0€
6
8C
LC
9
6
VC
CC
Ic
0¢
LI
OT
cI
vi
el
Cl

Lo feis cl Wave Noy tes (ee)

Joquinu u0ye}¢$

"966] Areniga, 0) Arenuey ‘uenstexy, eS] pue sajuLjal_ O1\sq ‘sojULJoT_ OJ[OH ‘[ovjey ues vuNnseyT Ul vOsNT[OJ] JOJ SuONe}S SuUNSIT[OS JO SIT J BqQUL

MOLLUSCA OF SOUTHERN CHILE

with radiating flecks of black and turquoise; girdle profusely covered
with long (to 7 mm), brown, corneous hairs, with dense minute
spicules beneath.

HABITAT. Underrocks in lowest eulittoral, on moderately exposed
shores. It has been recorded from throughout the tidal zone and to a
depth of 40 m (Leloup, 1956; Kaas & Van Belle, 1987). It appears to
be scarce on the shores of central and northern Chile (Guiler, 1959a;
Marincovich, 1973; Otaiza & Santelices, 1985).

RECORDS. Stations 12, 17. Kaas & Van Belle (1987) gave a range
from Cape San Lorenzo (Ecuador) to the Chonos Archipelago, and
our records are therefore at the southern extreme. However, Leloup
(1956) mentioned occurrence in the Magellan Strait (53°S), but
without details. Range: 146°S.

REMARKS. Both Kaas & Van Belle (1987) and Ferreira (1983)
mentioned that the girdle hairs characteristically protrude from the
sutures between the valves, but this was not the case in our material.
Dell (1971) also noted the lack of sutural hairs in some specimens
from Punta Pulga (42°S), and suggested that this might be due to
exposure.

Family ISCHNOCHITONIDAE

Ischnochiton (Ischnochiton) stramineus (Sowerby, in
Broderip & Sowerby, 1832)

(Figure 6B, D)

Chiton stramineus Sowerby, in Broderip & Sowerby, 1832: 104.

Ischnochiton (Ischnochiton) stramineus — Kaas & Van Belle, 1990:
173-176, fig. 78, map 38 (synonymy).

Ischnochiton stramineus — Kaas & Van Belle, 1998: 178.

Ischnochiton imitator E.A. Smith, 1881 —Leloup, 1956: 42-43, fig.
22.

DESCRIPTION. Valve area to 12.0 by 5.6 mm, maximum width of
girdle 1.0 mm; valves rather flattened; lateral triangles not raised or
differentiated; sculpture of fine, quincuncially arranged granules;
shell colour cream to fawn, sometimes stained with black deposits;
girdle cream to fawn, densely covered with short, imbricating
scales, each with about 6 ribs, converging towards recurved top of
scale (Fig. 6D); gills throughout pallial groove (holobranchial).

HABITAT. Understones and cobbles resting on silt, inlarge sheltered
rock pool, 0.3—0.5 m below low water of spring tide. Leloup (1956)
recorded it throughout the intertidal zone and to a depth of 22 m.

RECORDS. Station 14. Elsewhere from Islay (Peru) to Tierra del
Fuego and Magellan Strait (Kaas & Van Belle, 1990). Range: 17—
54°S.

REMARKS. Compare with Leptochiton medinae.
Ischnochiton (Haploplax) pusio (Sowerby, in Broderip &
Sowerby, 1832)

(Figures 2D, 6E)

Chiton pusio Sowerby, in Broderip & Sowerby, 1832: 105.

Ischnochiton pusio — Leloup, 1956: 44-45, fig. 23.

Ischnochiton (Haploplax) pusio — Kaas & Van Belle, 1994: 67-69,
fig. 27, map 18 (synonymy). Kaas & Van Belle, 1998: 153-154.

DESCRIPTION. Valve area to 15.7 by 8.4 mm, maximum width of
girdle 1.7 mm; valves smooth, very fine quincuncial granulation
visible at high magnification; shell colour brown to blackish brown,

115

usually with radiating flecks of white or turquoise; girdle rather wide,
brown to black, often banded, covered with relatively large, stout,
smooth, glossy, imbricating scales with square base, scales becoming
smaller towards inner and outer margins of girdle (Fig. 6E).

HABITAT. Under stones on gravel in shallow tidal channel, just
sublittoral; 10-15 m depth in sheltered bay, on substrate of cobbles
encrusted with calcareous red algae. This species has been reported
to be common intertidally, and to a depth of 90 m (Leloup, 1956;
Dell, 1971; Brattstroém, 1990; Kaas & Van Belle, 1994).

RECORDS. Stations 7, 15. Elsewhere Tumbes (Peru) to Tierra del
Fuego (Kaas & Van Belle, 1994). Range: 12—-54°S.

REMARKS. This is superficially similar to small specimens of
Chiton magnificus bowenii, but in that species the valves are glossy,
the girdle shows a definite inner zone of smaller scales and the scales
do not become smaller at the outer margin.

Family MOPALITDAE

Plaxiphora (Plaxiphora) aurata (Spalowsky, 1795)
(Figure 2B)

Chiton auratus Spalowsky, 1795: 88, pl. 13, figs 6a, b.

Plaxiphora aurata — Leloup, 1956: 25-26. Kaas & Van Belle, 1998:
26.

Plaxiphora (Plaxiphora) aurata — Kaas & Van Belle, 1994: 266—
269, fig. 108, maps 5, 28, 41 (synonymy).

Plaxiphora carmichaelis (Gray, 1828) — Ferreira, 1982: 43-45, figs
1-8 (synonymy).

DESCRIPTION. Valve area to 75 by 30 mm, maximum width of
girdle 16 mm; valves frequently eroded; jugal and pleural areas
smooth; lateral triangles defined by two nodulose radiating ribs, one
diagonal and one posterior; shell colour purple black with radiating
lines and stripes of pink or turquoise; girdle wide, fleshy, brown,
with minute spicules and sparse tufts of long (to 8 mm) corneous
hairs, frequently fouled with algae.

HABITAT. On and under rocks in low eulittoral, on sheltered and
sometimes muddy shores; in Macrocystis holdfasts, 3-5 m depth;
tolerant of reduced salinity (range 15—31%c). Leloup (1956) recorded
this species from throughout the intertidal zone, Brattstr6m (1990)
in its lowest part and Dell (1971) noted it also to a depth of 12 m. At
an intertidal estuarine site in Argentina it was reported to occur only
on shaded vertical rock walls, reaching densities of 7-12 per m?
(Lopez-Gappa & Tablado, 1997); in contrast, it was generally scarce
in the present study area.

RECORDS. Stations 1, 7, 14, 20, 22, 25, 26. Elsewhere Valparaiso
to Tierra del Fuego and Magellan Strait (Leloup, 1956; Dell, 1971;
Kaas & Van Belle, 1994), and outside the Chilean region on the
subantarctic islands and South Island, New Zealand (Kaas & Van
Belle, 1994). Range: 31-54°S.

REMARKS. This and Leptochiton medinae were the only chitons to
be found in the areas of significantly reduced salinity in the Golfo
Elefantes.

Family CHITONIDAE

Chiton (Amaurochiton) magnificus bowenii King &
Broderip, 1832

(Figures 2C, 6F)

116

Chiton bowenii King & Broderip, 1832: 338-339. Kaas & Van
Belle, 1998: 34.

Chiton (Amaurochiton) magnificus bowenii — Bullock, 1988:165—
166, figs 55, 56, 71, 76 (synonymy).

Chiton latus Sowerby, 1825 — Leloup, 1956: 50-54, figs 26, 27
(includes nominate subspecies).

DESCRIPTION. Valve areato46 by 24mm, maximum width of girdle
5 mm (total length up to 86 mm, Bullock, 1988); valves flattened to
carinate, glossy; jugal and pleural areas smooth; lateral triangles, head
and tail valves with indistinct radiating ribs; shell colour entirely
black, dark red, orange-pink or blue-grey, often with strong pattern of
longitudinal streaks on central region and radial streaks on lateral
triangles; girdle black, red or brown, with large, glossy, imbricating
scales, the innermost one third of the width of the girdle with slightly
smaller and narrower scales than the rest (Fig. 6F).

HABITAT. Common under rocks in lower eulittoral; small juveniles
dredged on cobbles at 10-15 m depth; moderately sheltered to
exposed coasts. Leloup (1956; as C. /atus) recorded the species both
intertidally and to 2-5 m depth, and Dell (1971; as C. latus)
mentioned a maximum depth of 13 m. In central Chile the typical
subspecies inhabits pools and boulder fields from high to low tide, is
larger and more common in exposed localities, but absent from rock
walls (Otaiza & Santelices, 1985; as C. latus).

RECORDS. Stations 1, 5, 7, 12, 14, 15, 17. Elsewhere I. Chiloé,
Magellan Str. and Tierra del Fuego (43—53°S); typical subspecies I.
San Lorenzo (Peru) to I. Chiloé (Bullock, 1988) (12-43°S). Total
range of species: 12—53°S.

REMARKS. Bullock (1988) distinguished C. m. bowenii from the
typical northern subspecies by its smooth sculpture, more carinate
valves, more elongate outline, brighter coloration and smaller girdle
scales. He noted the ‘nearly complete geographical isolation of the
two’, although this is probably a sampling artefact. In Isla Chiloé he
reported that both types could be found, together with intermediates,
and this appears to question the validity of the subspecific distinc-
tion. The present material shares the smooth sculpture, small scales
and frequently bright coloration of the southern form, but the valve
profile and outline are more variable. Additional material is required
to determine whether the subspecies are indeed distinct entities, or if
there is a latitudinal cline. The synonymy of the nominate subspe-
cies 1s complex, and includes C. striatus Barnes, 1824, C. latus
Sowerby, 1825, C. olivaceus Frembly, 1827 and C. subfuscus
Sowerby, 1832 (see Bullock, 1988). Small specimens could be
confused with [schnochiton pusio.

Chiton (Chondroplax) granosus Frembly, 1827
(Figure 2J)

Chiton granosus Frembly, 1827: 200-201. Leloup, 1956: 48-50,
figs 24, 25. Marincovich, 1973: 43, fig. 98. Osorio, Atria & Mann,
1979: 13, fig. 5. Kaas & Van Belle, 1998: 84.

Chiton (Chondroplax) granosus — Bullock, 1988: 185-187, figs 96,
97, 103, 140, 141, 143, 144.

DESCRIPTION. Valve area to 44 by 25 mm, maximum width of
girdle 7 mm (total length up to 80 mm, Osorio et al., 1979); central

D.G. REID AND C. OSORIO

area with longitudinal striations; lateral triangles, head and tail
valves with radiating rows of coarse nodules; valves usually eroded
so that sculpture is not visible; shell colour dark brown to black, with
broad longitudinal pale stripe on either side of jugal tract, striking
even in eroded specimens; girdle with coarse black scales.

HABITAT. In wave-surge gullies and crevices, and on cliffs, in
lower eulittoral, on exposed shores. This species is abundant in
southern, central and northern Chile, mainly on exposed cliffs in the
mid to low intertidal zone (Jara & Moreno, 1984; Otaiza & Santelices,
1985; Brattstr6m, 1990), although it has also been reported from the
undersides of rocks (Leloup, 1956; Marincovich, 1973) and at the
high tide level (Frembly, 1827; Leloup, 1956; Brattstr6m, 1990).

RECORDS. Stations 12, 13, 17. This extends the known range of
Tumbes (Peru) to I. Chiloé (Bullock, 1988). Range: 12-46°S.

REMARKS. This species was found infrequently in the Estero
Elefantes, and then only on the most wave-exposed of the sites
visited. Moreno & Jaramillo (1983) reported that the main food of C.
granosus is barnacle larvae.

Tonicia atrata (Sowerby, 1840)
(Figure 2K)

Chiton atratus Sowerby, 1840: 294.
Tonicia atrata—Leloup, 1956: 59-67, figs 31-35 (synonymy). Kaas
& Van Belle, 1998: 25 (synonymy).

DESCRIPTION. Valve area to 85 by 30 mm, maximum width of
girdle 13 mm; jugal area with deep longitudinal striae; lateral
triangles not distinct; entire surface with fine, regular granulation
(not evident in large, eroded specimens); mucro of tail valve almost
central, post-mucronal slope convex; shell colour purplish black,
beaks often pale pink, some specimens with fine concentric lines
and irregular radial rays; girdle macroscopically smooth, with mi-
croscopic spicules, flesh pink.

HABITAT. Under stones and in pools, in lower eulittoral, on shel-
tered and moderately sheltered shores. Leloup (1956) and Brattstr6m
(1990) also recorded this species from the mid and low eulittoral,
and Dell (1971) down to a depth of 10 m.

RECORDS. Stations 1,5, 7,12, 14, 15, 20. Elsewhere Puerto Montt
to Tierra del Fuego (Leloup, 1956; Dell, 1971). Range: 40-54°S.

REMARKS. Leloup (1956) described the variation in valve form
and sculpture in this species; the present specimens correspond with
his figures of the synonymous T. fastigiata (Sowerby, 1843).

Tonicia chilensis (Frembly, 1827)
(Figure 2E)

Chiton chilensis Frembly, 1827: 204—205.
Tonicia chilensis — Kaas & Van Belle, 1998: 45 (synonymy).
Tonicia elegans (Frembly, 1827) —Leloup, 1956: 69-77, figs 38-46.

DESCRIPTION. Valve area to 37 by 15 mm, maximum width of
girdle 6 mm (total length up to 70 mm, Kaas & Van Belle, unpubl.);
jugal area with a few longitudinal striae, elsewhere almost smooth;

Fig. 2 A. Chaetopleura (Chaetopleura) peruviana (44 mm). B. Plaxiphora (Plaxiphora) aurata (42 mm). C. Chiton (Amaurochiton) magnificus bowenii
(40 mm). D. Ischnochiton (Haploplax) pusio (14 mm). E. Tonicia chilensis (20 mm). F, G. Scurria parasitica (15 mm). H, I. Scurria ceciliana (19 mm).
J. Chiton (Chondroplax) granosus (43 mm). K. Tonicia atrata (36 mm). L, M. Nacella (Patinigera) magellanica (typical form; 40 mm). N, O. Nacella
(Patinigera) magellanica (form venosa; 37 mm). P, Q. Nacella (Nacella) mytilina (32 mm). (All specimens from study area; NHM collection).

MOLLUSCA OF SOUTHERN CHILE

rae =
actT”’ oa
alg? —
ee

a al

118

lateral triangles often indistinct, but sometimes marked by a raised
and nodulose diagonal line, and lateral triangles sometimes bearing
small radial pustules; mucro of tail valve near anterior margin, post-
mucronal slope concave; shell colour variable, pale pink, orange,
pale green or turquoise, with fine red or purple longitudinal and
radial lines, or finely marbled pattern; girdle macroscopically smooth,
flesh pink.

HABITAT. Under stones in calcareous red algal zone of sublittoral
fringe in large, sheltered, rock pool; dredged from 10-15 m in
sheltered bay, on substrate of cobbles encrusted with calcareous red
algae. At intertidal sites in central Chile this species was also mainly
found submerged in pools (Otaiza & Santelices, 1985). Leloup
(1956) recorded it from intertidal habitats both sheltered and ex-
posed, and to a depth of 13 m.

RECORDS. Stations 7, 12. Elsewhere Tumbes (Peru) to Tierra del
Fuego (Leloup, 1956; Dell, 1971). Range: 12-54°S.

REMARKS. Both colour and sculpture of this species are highly
variable, resulting in a complex synonymy. Of the forms differenti-
ated by Leloup (1956), the present specimens correspond with f.
lineolata (Frembly, 1827), by virtue of their striking colour pattern
and mainly smooth valves, although the sculpture sometimes ap-
proaches f. grayii Sowerby, 1832.

Class Gastropoda
Family NACELLIDAE

Nacella (Nacella) mytilina (Helbling, 1779)
(Figure 2P, Q)

Patella mytilina Helbling, 1779: 104-106, pl. 1, figs 5, 6.

Nacella mytilina — Dell, 1971: 201—202 (synonymy). Castellanos &
Landoni, 1988: 27, pl. 4, figs 9, 10.

Nacella (Nacella) mytilina — Powell, 1973: 192, pl. 73, fig. 9, pls
173, 174 (synonymy). Ubaldi, 1985: 11-12, 17-18, figs 1-4.

DESCRIPTION. Shell to 32 by 24 mm, height 13 mm; shell thin,
translucent; apex one third from anterior edge; surface almost
smooth, but with faint radial riblets; horn colour, with radiating
white streaks; interior silvery iridescent.

HABITAT. On fronds of Macrocystis growing from depth of 10-15
m near shore; rare, only 3 specimens found despite examination of
many plants. It is acommon member of the epibiotic community on
Macrocystis further south in the Magellanic region (Castilla, 1985).

RECORDS. Stations 1, 14. Elsewhere I. Wellington, Magellan Strait
and Tierra del Fuego (Dell, 1971; Powell, 1973). The present
records are the northernmost. Range: 46—-55°S.

REMARKS. The shell of this species is highly variable, ranging
from semitransparent to moderately solid, and from smooth to
ribbed. The position of the apex is also variable; in typical speci-
mens (Powell, 1973: pl. 173, figs 1, 2) it is at the anterior end,
whereas in the present material it is at about one third of the shell
length from the anterior margin. It is notable that the Nacellidae are
presently accorded full familial status in the superfamily Patelloidea
(Sasaki, 1998: 208-209).

Nacella (Patinigera) magellanica (Gmelin, 1791)
(Figure 2L—O)

Patella magellanica Gmelin, 1791: 3703.
Patinigera magellanica — Dell, 1971: 204. Osorio, Atria & Mann,

D.G. REID AND C. OSORIO

1979: 14-15, fig. 8. Castellanos & Landoni, 1988: 2, pl. 3, figs 1—
3:

Nacella (Patinigera) magellanica magellanica— Powell, 1973: 198,
pl. 73, figs 14, 15, pl. 178, figs 1, 2 (synonymy).

Patella venosa Reeve, 1854: sp. 18, pl. 10, figs 18 a—c.

Nacella (Patinigera) magellanica venosa — Powell, 1973: 198-199,
pl. 180.

DESCRIPTION. Shell to 71 by 63 mm, height 37 mm; shape vari-
able, from smooth, low-conical (height/length 0.32), round (width/
length 0.98) (form venosa, Fig. 2N, O) to radially ribbed, high-
conical (height/length 0.77), oval (width/length 0.87) (typical
magellanica, Fig. 2L, M); external colour also variable, typically
grey with dark brown radial stripes, but form venosa may in addition
be black, or cream with sparse streaks or chevrons; interior silvery
iridescent with exterior pattern showing through, spatula always
dark coppery iridescent.

HABITAT. This is an abundant species in a wide range of intertidal
rocky habitats, on exposed and moderately sheltered shores, on cliffs
and stones, from the lower barnacle zone, through the Mytilus zone, to
the low water mark. The species does not occur subtidally. On
moderately exposed vertical rock faces it is most common in a super-
ficially bare zone between the Mytilus zone above, and the calcareous
red algal zone below; in this intermediate region other herbivorous
molluscs are also common (Chiton granosus, Tegula atra, Fissurella
picta), and grazing pressure may maintain the bare rock surface.
Nacella magellanica was found at stations with salinity down to 15—
20%c. Larger specimens were found on open rock surfaces, smaller
animals beneath stones and in crevices. After 2—3 days of diurnal low
tides and clear sunny weather, animals towards the upper limit of
distribution were observed (2—3 Feb. 1998) to suffer heat coma,
dropping off the rock and dying. The distribution and density of this
species have been studied in the Magellan Strait (Guzman, 1978).

RECORDS. Stations 1,5,6,7,8, 13, 14,17,20,21,22,25.Else-where
I. Chiloé to Tierra del Fuego and Magellan Strait (Powell, 1973; Dell,
1971). The northern limit of this species is uncertain. Brattstrom &
Johanssen (1983) mention ‘Patinigera deaurata (Gmelin, 1791)
from six locations between Laguna San Rafael and Seno Reloncavi
(41°29'33"S), and mention P. magellanica from Valparaiso to the
Magellan Strait. Brattstr6m (1990) recorded N. magellanica com-
monly in Seno Reloncavi and listed a single occurrence of N. aenea
Martyn, 1784 (an invalid name for NV. deaurata). N. Nacella deaurata
is a species recognized by Powell (1973), who gave its range as the
Magellan Strait, Tierra del Fuego and the Falkland Is.; in the Beagle
Channel this species is common intertidally, together with N.
magellanica (DGR, pets. obs.), but it was not seen in our study area.
It seems likely that the records by Brattstr6ém & Johanssen (1983) of
deaurata from the Chilean archipelago arose from misidentification
of the ribbed form of N. magellanica, and accordingly we assign their
record from Seno Reloncavi to that species. The source of their record
of N. magellanica from Valparaiso is unknown, and we consider this
unreliable. Range: 41—55°S.

REMARKS. The systematics of the genus Nacella are still some-
what confused. In the most recent monograph, Powell (1973)
recognized the smoother, more round and more brightly coloured
examples from Isla Chiloé as the geographical subspecies N. m.
venosa, contrasting these with the more strongly ribbed, taller, more
oval shells of the typical forms from the southern part of the range.
In the present study the majority of specimens conformed to the
northern subspecies (Fig. 2N, O), but at station 25 in the lower
salinity (and perhaps colder) environment of the Golfo Elefantes,
the shells were mainly of the typical form (Fig. 2L, M). Inter-

MOLLUSCA OF SOUTHERN CHILE

mediates appear to connect these two forms and therefore we have
not retained the subspecific distinction. Nacella deaurata (Gmelin,
1791) was recorded, probably erroneously, from “Laguna San Rafael’
by Brattstr6m & Johanssen (1983; see above); this southern species
is a more elongate oval shape, with nodular radial ribs. Nacella
magellanica was reportedly one of the principal food species of the
Fuegian Indians (Osorio et al., 1979), but was not found in the
middens on Isla Traiguén.

Family LEPETIDAE

Tothia coppingeri (Smith, 1881)
(Figure 7A)

Tectura (Pilidium) coppingeri E.A. Smith, 1881: 35, pl. 4, figs 12,
12a.

Lepeta coppingeri — Castellanos & Landoni, 1988: 32, pl. 1, fig. 6,
pl. 3, fig. 9. Linse, 1997: 27.

Tothia coppingeri — Moskalev, 1977: 62-64, figs 5, 6. Dell, 1990:
105-106, figs 185, 186 (synonymy).

DESCRIPTION. Shell to 4.2 by 3.1 mm; delicate, translucent, apex
close to anterior end; sculptured by numerous fine, scaly, radial
riblets, but sculpture sometimes obsolete; colour usually white,
sometimes orange brown, or dark brown with white rays.

HABITAT. 10—15 m depth, on substrates of cobbles encrusted with
calcareous red algae, and of cobbles and shell debris on silt. It has
been recorded from depths of 5—1108 m (Dell, 1990; Linse, 1997).

RECORDS. Stations 7, 14, 25. Elsewhere Tierra del Fuego and
Magellan Strait, and more widely in Falkland Is and circum-Antarc-
tic (Dell, 1990). According to Dell (1990) the northern limits are not
well defined, so that our records may be the northernmost for this
species. Range: 46-78°S.

Family LOTTIIDAE

Scurria ceciliana (d’ Orbigny, 1841)
(Figure 2H, I)

Patella ceciliana d’ Orbigny, 1841: 482, pl. 81, figs 4-6.

Patelloida ceciliana — Dell, 1971: 199-200 (synonymy).

Collisella ceciliana — Marincovich, 1973: 19-20, fig. 33 (syn-
onymy). Castellanos & Landoni, 1988: 2, pl. 3, figs 10, 11, pl. 4,
fig. 2.

Scurria ceciliana — Espoz, Guzman & Castilla, 1995: 191-197, fig.
3d.

DESCRIPTION. Shell to 20 by 18 mm, height 7 mm; low-conical,
apex at one third of shell length from anterior margin; sculptured by
12—15 rounded ribs that crenulate the margin; colour white, with fine
black or brown tessellation between ribs, merging into radial lines at
margin; interior white or greenish, exterior pattern shows through at
margin, spatula irregular, dark brown or of several axial brown
streaks.

HABITAT. Onsurface of rocks with green algae in barnacle zone, in
upper eulittoral on moderately sheltered shores. Dell (1971) and
Brattstr6m (1990) recorded this species mainly from the mid and
upper littoral, but also lower on the shore. In northern Chile,
Marincovich (1973) found it in the middle and lower intertidal.

RECORDS. Stations 1, 8. Elsewhere Pucusana (Peru) to Tierra del
Fuego and Magellan Strait (Dell, 1971; Marincovich, 1973). Owing

119

to taxonomic confusion in this group (see below), the geographical
distribution is uncertain. Provisional range: 12—54°S.

REMARKS. According to Lindberg (1988), the lottiid limpets of
Chile are all assigned to the genus Scurria. These comprise a poorly
known complex of species, much in need of critical revision (contrast
the treatments by Dell, 1971; Marincovich, 1973; Ramirez, 1974;
Hockey et al., 1987; Espoz et al., 1995). The present form is
identified as S. ceciliana, since it corresponds with d’Orbigny’s
(1841) description and figure (the types are lost), and resembles
specimens from the type locality in the Falkland Islands (NHM). This
species is one of several which, when strongly eroded at the apex, can
show a striking mimetic resemblance to a large barnacle. This is
achieved by the exposure of the dark brown and streaked shell layers
beneath the myostracum, which produces a pattern resembling the
tergal and scutal plates of a barnacle (Hockey et al., 1987). Erosion of
the shell is facilitated by the lichen Thelidium litorale (Espoz et al.,
1995). In the present samples of S. ceciliana only a few specimens
show this erosion pattern, and in these the mimicry is less striking
than in Scurria species from further north on the Chilean coast.

Scurria parasitica (d’Orbigny, 1841)
(Figure 2F, G)

Patella parasitica d’ Orbigny, 1841: 481, pl. 81, figs 1-3.
Scurria parasitica —Marincovich, 1973: 21—22, fig. 37 (synonymy).

DESCRIPTION. Shell to 15 by 13 mm, height 8 mm; high conical to
tall cap-shaped, apex at one third of shell length from anterior
margin; outline oval to almost round; plane of base often curved to
fit shell substrate; radial sculpture weak, of fine striae, often eroded
away or obsolete, occasionally developing weak radial ribs; colour
variable, often varying in concentric zones on the same shell,
usually with 13-20 broad radial white stripes, with brown or black
marbled or lineated sectors between; may be uniformly blackish
brown, or flecked with white; interior white with irregular brown
spatula, external pattern showing through at margin.

HABITAT. Onshells of large molluscs (Nacella, Acanthina, Mytilus)
in eulittoral, on sheltered and moderately exposed shores; also on
shell material on eroding edge of large midden. In central and
northern Chile the species reaches larger size (29 mm) and inhabits
large chitons, Fissurella and other Scurria species (d’Orbigny,
1841; Marincovich, 1973).

RECORDS. Stations 1, 7, 10, 12, 14. Elsewhere Callao (Peru)
(NHM), Chincha Is (Peru) to Talcahuano (Marincovich, 1973),
extended southwards by the present records. Range: 12-46°S.

Family FISSURELLIDAE

Puncturella (Puncturella) conica (d’ Orbigny, 1841)
(Figure 7B)

Rimula conica d’ Orbigny, 1841: 471, pl. 78, figs 10, 11.

Puncturella conica — Powell, 1951: 86-87 (synonymy). Powell,
1960: 127. Dell 1971: 178-179, pl. 5, figs 10, 11, 14, 15 (syn-
onymy). Arnaud, 1972: 113-114. Castellanos & Landoni, 1988:
20, pl. 3, fig. 1

Puncturella cognata (Gould, 1852) — Powell, 1951: 86. Linse, 1997:
Di.

Puncturella spirigera Thiele, 1912 — Powell, 1960: 127. Dell, 1990:
76, figs 125, 127.

120

DESCRIPTION. Shell 5.5 by 4.0 mm, height 3.5 mm (to 16 mm in
length, Powell, 1951); tall cap-shaped with coiled apex; short longi-
tudinal slit just anterior to shell apex; sculpture of 25 radial ribs
made scaly by growth lines, with a smaller riblet in each interspace;
white.

HABITAT. Single dead shell dredged in 10-15 m, on substrate of
cobbles encrusted with calcareous red algae, near shore in sheltered
bay. Dell (1971) recorded the species from 6—20 m in southern
Chile, Powell (1951) from 60-342 m, and Dell (1990) to 2804 m in
the Ross Sea (if the synonymy with P. spirigera is accepted).

RECORDS. Station 7 (single dead shell). Elsewhere I. Chiloé (Dell,
1971) to Magellan Strait, also Falkland Is (Powell, 1951) and
perhaps circum-Antarctic (Dell, 1990). Range: 42—75°S.

REMARKS. Thetaxonomy of the southern species of P. (Puncturella)
is unclear, and critical revision is required (Dell, 1990). They are
closely similar to P. (P.) noachina (Linnaeus, 1771) from the north-
ern Pacific and Atlantic Oceans, but are usually regarded as
specifically distinct. The single shell found has been compared with
the holotype (NHM) from the Falkland Islands, and closely resembles
it in size and sculpture, although slightly less acutely conical.
Previous authors differ in the number of species recognized in this
group, according to their interpretation of differences in shell shape
and degrees of sculpture. However, in view of the intraspecific
variation in these features described in South African specimens by
Herbert & Kilburn (1985), it is possible that only a single species
may be involved.

Fissurella (Fissurella) nigra Lesson, 1831
(Figure 3A)

Fissurella nigra Lesson, 1831: 412-413. Osorio, Atria & Mann,
1979: 17, fig. 13. Castellanos & Landoni, 1988: 15, pl. 2, fig. 5.
Oliva & Castilla, 1992: fig. 9.

Fissurella (Fissurella) nigra — McLean, 1984: 52-55, figs 200-211
(synonymy).

DESCRIPTION. Shell to 104 by 75 mm, height 40 mm (maximum
length 140 mm, Bretos,Quintana & Ibarrola, 1988); outline elongate
oval, narrowed anteriorly, base resting flat, foramen slightly anterior
of centre; sculpture almost smooth in large shells, except for concen-
tric growth lines, but with numerous fine radial ribs in juveniles;
colour purple-black, foramen outlined in white (eroded to reveal
inner aragonitic shell layer); interior white, margin (external calcitic
layer) of outer black and inner translucent gray zone; head and
tentacles black, sides of foot dark grey to black, with a row of small
white tubercles.

HABITAT. Common beneath rocks on sheltered and moderately
sheltered boulder and rocky shores, in mid to low eulittoral zone. Fre-
quently in groups of up to 7 individuals under a single rock. A similar
habitat was reported by McLean (1984), but it can also be found in the
immediate subtidal zone (Bretos, Quintana & Ibarrola, 1988).

RECORDS. Stations 1, 7, 14, 15, 20, 21. Elsewhere Valparaiso to I.
Navarino (McLean, 1984). Range: 33-55°S.

REMARKS. All the Chilean Fissurella species are edible, and the

D.G. REID AND C. OSORIO
total extraction for 1997 was 3063 tonnes (SERNAP, 1998).

Fissurella (Fissurella) oriens oriens Sowerby, 1835
(Figure 3C)

Fissurella oriens Sowerby, 1835: 124.

Fissurella (Fissurella) oriens oriens — McLean, 1984: 49-52, figs
178-199 (synonymy).

Fissurella oriens oriens — Castellanos & Landoni, 1988: 14, pl. 2,
figs 10, 11.

DESCRIPTION. Shell to 54 by 30 mm, height 12 mm (maximum
length 70 mm, McLean, 1984); outline more or less narrowly oval,
narrowed anteriorly, either sides or ends of shell slightly raised when
on flat surface, foramen almost central; sculpture smooth, or with
very fine indistinct striae in young shells; colour variable, white to
pink, often with broad purple grey rays (not divided into lines), but
pattern may be absent; interior white with narrow translucent mar-
gin; animal pale, head grey, sides of foot mottled pink and grey,
tentacles and mantle margin yellowish.

HABITAT. Under rocks and in rock pools, in lowest eulittoral, on
moderately sheltered and moderately exposed shores; juveniles
found in holdfasts and on fronds of Macrocystis, 10-15 m depth.
Unidentified fissurellids made up the major molluscan component
of the invertebrate biomass associated with Macrocystis holdfasts in
the Beagle Channel (Ojeda & Santelices, 1984). McLean (1984)
recorded this species from the lower intertidal to 30 m depth.

RECORDS. Stations 1, 5,9, 14, 17. Elsewhere Valparaiso to Tierra
del Fuego, of which specimens north of about 37°S belong to the
subspecies F. o. fulvescens Sowerby (McLean, 1984). Total range:
33-56°S.

REMARKS. This species is distinguished from the similar F: picta
by its lack of radial ribs and by its paler, yellowish animal, and
occupies a lower and more sheltered habitat. According to the
detailed monograph of the Magellanic species of Fissurella by
McLean (1984), an additional species, F. radiosa Lesson, 1831,
occurs in the region and, although similar to F. oriens, can be
distinguished by its strong radial ribs.

Fissurella (Fissurella) picta picta (Gmelin, 1791)
(Figure 3B)

Patella picta Gmelin, 1791: 3729.

Fissurella (Fissurella) picta picta — McLean, 1984: 37-43, figs
123-146 (synonymy).

Fissurella picta—Osorio, Atria & Mann, 1979: 16, fig. 11. Castellanos
& Landoni, 1988: 1, pl. 2, figs 3, 4. Oliva & Castilla, 1992: fig. 3.

DESCRIPTION. Shell to 88 by 56 mm, height 32 mm; outline
narrowly oval, narrowed anteriorly, sides slightly raised when on
flat surface, foramen slightly anterior of centre; sculpture of sharp
narrow ribs of varying size, and irregular concentric growth lines;
colour white to grey, with broad purple-black rays, each divided into
several dark lines; interior white, margin (external calcitic layer)

Fig.3 A. Fissurella (Fissurella) nigra (76 mm). B. Fissurella (Fissurella) picta picta (60 mm). C. Fissurella (Fissurella) oriens oriens (53 mm).
D. Margarella violacea (7.1 mm). E. Diloma nigerrima (18 mm). F, G. Crepidula dilatata (sensu lato) (72 mm). H, I. Trochita trochiformis (54 mm).
J. Tegula (Chlorostoma) atra (30 mm). K. Acanthina monodon (form monodon from exposed shore at station 14; 46 mm). L. Acanthina monodon (form
unicornis from sheltered shore at station 1; 57 mm). M. Argobuccinum (Argobuccinum) pustulosum ranelliforme (78 mm). N. Trophon plicatus (51 mm).
O. Concholepas concholepas (94 mm). (All specimens from study area; NHM collection).

MOLLUSCA OF SOUTHERN CHILE

122

showing external rayed pattern; head and tentacles dark grey to
black, sides of foot dark grey, densely mottled with white tubercles.

HABITAT. On rock and in crevices, from mid eulittoral Mytilus
zone to lowest eulittoral, on exposed coasts. Common in super-
ficially bare grazed zone between Mytilus zone above and calcareous
red algal zone of sublittoral fringe, on moderately exposed cliffs,
together with Nacella magellanica, Chiton granosus and Tegula
atra. This is an abundant species in southern Chile, reaching densi-
ties of 17 per m? in areas protected from humans (Jara & Moreno,
1984) and occurring in the mid to low eulittoral on both exposed and
sheltered coasts (Bretos, Gutiérrez & Espinoza, 1988; Godoy &
Moreno, 1989). It is restricted to the intertidal zone (McLean, 1984).

RECORDS. Stations 5, 9, 13, 14, 17. Elsewhere the species occurs
from Valparaiso to Tierra del Fuego, with overlap between the
nominate, southern subspecies and the northern F: p. lata Sowerby
on I. Chiloé (McLean, 1984). Total range: 33-56°S.

REMARKS. This species is the major herbivore of the mid and low
shore on exposed rocky coasts in southern Chile, grazing principally
on Iridaea. It is one of the main species in commercial limpet
catches. In the vicinity of human settlements, where collection
pressure on this species is strong, algae proliferate on the shore.
However, when humans were excluded from a shore near Valdivia
the density of F picta increased to 3 per m* and algal cover was
reduced (Moreno & Jaramillo, 1983; Moreno, Sutherland & Jara,
1984; Duarte, Asencio & Moreno, 1996). On the more remote
shores of the present study area the density of F. picta remains high
in suitable habitats of moderate wave exposure, and grazing pres-
sure by this and other herbivores appears to result in a low eulittoral
zone without large macroalgae.

Family TROCHIDAE

Tegula (Chlorostoma) atra (Lesson, 1831)
(Figure 3J)

Trochus ater Lesson, 1831: 344, pl. 16, fig. 2, 2’.

Chlorostoma atra — Dell, 1971: 195 (synonymy).

Tegula (Chlorostoma) atra — Marincovich, 1973: 24, fig. 42 (syn-
onymy).

Tegula atra—Osorio, Atria & Mann, 1979: 17-18, fig. 14. Castellanos
& Landoni, 1989: 27, pl. 4, fig. 4.

DESCRIPTION. Shell to 39 by 41 mm (to 57 mm, Osorio et al.,
1979); trochoidal with rounded periphery; surface smooth; no um-
bilicus, blunt tooth at base of columella; colour dull purple black
above, apex often eroded, base whitish; interior nacreous.

HABITAT. Abundant on rocky shores of sheltered and moderate
exposure; on and under cobbles, boulders and on cliffs; mid to low
eulittoral, from Mytilus zone to zone of calcareous red algae in
sublittoral fringe, and an important herbivore of the bare, grazed belt
between these two zones on moderately exposed cliffs; rarely
sublittoral (one specimen from 7—9 m, station 22); rare at station 22
where salinity was recorded as 15—21%c. In central and northern
Chile this species is typical of the Lessonia and Lithothamnion zone
of the sublittoral fringe, on sheltered and moderately exposed coasts
(Guiler, 1959a, b; Marincovich, 1973; Ruiz & Giampaoli, 1981).

RECORDS) Stations [enon 7a en LOS 2 AS ale O lee
Elsewhere Pacasmayo (Peru) to Magellan Strait (Marincovich, 1973).
Range: 7—54°S.

D.G. REID AND C. OSORIO

REMARKS. This is an edible species; the national harvest in 1997
was 159 tonnes (SERNAP, 1998).

Diloma nigerrima (Gmelin, 1791)
(Figure 3E)

Turbo nigerrimus Gmelin, 1791: 3597.

Diloma nigerrima — Dell, 1971: 195-197, pl. 1, fig. 8, pl. 2, fig. 2
(synonymy). Marincovich, 1973: 23-24, fig. 45. Powell, 1979:
53. Castellanos & Landoni, 1989: 29, pl. 4, fig. 6.

DESCRIPTION. Shell to 21 by 19 mm; turbinate; sculptured with
indistinct spiral grooves, stronger on spire whorls, strongest groove
just below suture; colour dull purple black, including base, apical
whorls often eroded to reveal nacre; interior nacreous.

HABITAT. Abundant in clusters beneath stones in upper eulittoral,
on moderately sheltered cobble and boulder shores. A similar
habitat was noted by Dell (1971) and Brattstrém (1990) on I. Chiloé,
with additional records from the mid and low eulittoral; in northern
Chile Marincovich (1973) recorded it in clusters in the lower
intertidal zone.

RECORDS. Stations 7, 8. Elsewhere Salaverry (Peru) to Magellan
Strait (Marincovich, 1973). The same (Powell, 1979) or a closely
related species (Dell, 1971) occurs in New Zealand. Range: 8-54°S.

REMARKS. This species was found at only two stations, where it
was abundant and found at levels above those occupied by the
superficially similar Tegula atra.

Margarella violacea (King & Broderip, 1832)
(Figure 3D)

Margarita violacea King & Broderip, 1832: 346. Sowerby, 1838:
24.

Photinula violacea — Strebel, 1905a: 145-152, pl. 5, figs 1-8, 12, 13.

Margarella violacea — Powell, 1951: 96. Deambrosi, 1969: 51-52,
fig. 1 (radula). Dell, 1971: 194 (synonymy). Castellanos &
Landoni, 1989: 16, pl. 3, fig. 4.

Promargarita violacea — Dell, 1990: 77-78.

DESCRIPTION. Shell to 6.0 by 6.7 mm (to 10.3 by 11.5 mm, Dell,
1971); trochoidal with rounded whorls, umbilicus minute or closed;
surface smooth, shining; colour iridescent violet pink, white around
umbilicus; interior nacreous; operculum corneous.

HABITAT. Dredged from 10-15 m depth, on substrates of cobbles
with encrusting calcareous red algae, silt with scattered pebbles and
shells, and shell gravel. Not common. In the original description it
was noted that this species is found on the fronds of Macrocystis in
the Magellan Strait (King & Broderip, 1832), and it has also been
recorded from both fronds (Dell, 1971; Castilla, 1985) and holdfasts
(Ojeda & Santelices, 1984) of kelp in the Beagle Channel; it was not
found on MacrocysStis in our survey. Dell (1971) recorded specimens
from the intertidal and to a depth of 12 m.

RECORDS. Stations 7, 14, 25. Elsewhere Puerto Eden to Tierra del
Fuego, also Falkland Is (Dell, 1971), so that ours are the most
northerly records. Range: 46—-55°S.

REMARKS. Confusion surrounds the specific identification, generic
assignment and relationships of the Magellanic and Antarctic species
variously classified in Margarites, Margarita, Margarella and
Promargarita. The present specimens are smaller and have a slightly
lower rate of whorl expansion than the types of the species (NHM)
from the Magellan Strait, although shape is evidently variable

MOLLUSCA OF SOUTHERN CHILE

(Strebel, 1905a). The bright pink coloration of the shell fades in
museum specimens, and this species is then more difficult to separate
from the similar Margarella expansa (Sowerby, 1838); when fresh,
the latter is usually olive in colour, with a vivid green iridescence on
the spire whorls, and the shape is lower-spired with a more expanded
final whorl (Strebel, 1905a; Powell, 1951). In a revision of the
suprageneric classification of trochoideans, Hickman & McLean
(1990) used acombination of gill and radular characters to distinguish
the Margaritinae (including Margarites, mainly from high latitudes of
the northern hemisphere) and Gibbulini of the Trochinae (including
Margarella from southern high latitudes). However, they pointed out
that both radular types can be found among the southern species, and
that a revision is required. Using a different radular character,
Deambrosi (1969) segregated two groups among the southern species,
for which the names Margarella and Margarites were used, although
the relationship with northern forms was not addressed. Later, Dell
(1990) noted that the type species of Margarella in fact belonged to the
‘Margarites’ group, and therefore used the next available generic
name, Promargarita, for the former. Until these relationships are
resolved, we have retained the familiar generic name Margarella.

Family TURBINIDAE

Homalopoma cunninghami (Smith, 1881)

(Figure 7F)

Collonia cunninghami E.A. Smith, 1881: 33, pl. 4, figs 10, 10a.

Homalopoma cunninghami — Dell, 1971: 193-194 (synonymy).
Castellanos & Landoni, 1989: 31, pl. 2, fig. 2, pl. 4, fig. 7.

DESCRIPTION. Shell to 3.9 by 4.6 mm; globular; surface with fine
spiral grooves, small umbilicus in young shells, becoming closed in
adults; colour dark pink to magenta; interior nacreous; operculum
calcified externally.

HABITAT. Dredged from 10—15 m depth, on substrates of cobbles
with encrusting calcareous red algae, and on pebbles with shell
gravel. Recorded from 66 m depth by Powell (1951).

RECORDS. Stations 7, 14. Elsewhere I. Chiloé to Magellan Strait
(Dell, 1971) and Tierra del Fuego (Powell, 1951). Range: 43-55°S.

REMARKS. Superficially this speciesresembles Margarellaviolacea,
with which it is found, but is distinguished by its pink (not violet)
coloration, spirally striated surface and calcified operculum. The
thickness of calcification on the operculum is apparently variable,
being thick only at the margin and thinner centrally in the present
specimens, although thick over the whole surface in the types (NHM).

Family LITTORINIDAE

Nodilittorina araucana (dq Orbigny, 1840)
(Figure 7C)

Littorina araucana qd Orbigny, 1840: 393, pl. 53, figs 8-10.

Littorina (Austrolittorina) araucana — Marincovich, 1973: 25, figs
48, 49 (synonymy).

Nodilittorina (Nodilittorina) araucana — Reid, 1989: 99.

DESCRIPTION. Shell to 12 by 7 mm; tall conical, solid; smooth or
with fine spiral lines, but spire whorls usually eroded; colour purple
black to purple brown; aperture black with basal white stripe.

HABITAT. Locally abundant, among uppermost barnacles and the
crustose red alga Hildenbrandia in upper eulittoral on moderately

123

exposed shores. Sometimes on algal rocks, shell midden material
and among Mytilus, in upper and mid eulittoral on sheltered shores.
In central and northern Chile this species is also typical of the upper
eulittoral barnacle zone on exposed coasts (Ruiz & Giampaoli,
1981; Santelices, 1991), although Marincovich (1973) observed
that, while generally common, it was absent from strongly exposed
shores at Iquique. Dell (1971) and Brattstr6m (1990) recorded this
species from throughout the littoral zone.

RECORDS. Stations 1, 10, 12, 14. Elsewhere Salaverry (Peru) to I.
Chiloé (D.G. Reid, unpublished), Canal Moraleda (45°S; Brattstrom
& Johanssen, 1983), extended southwards by the present records.
Range: 8-46°S.

REMARKS. Although very abundant on some shores, this species
had an unpredictable occurrence in the Estero Elefantes. The pelagic
egg capsules and planktotrophic reproduction of this species were
described by Jordan & Ramorino (1975).

Family CALYPTRAEIDAE

Crepidula dilatata Lamarck, 1822 [sensu lato]
(Figure 3F, G)

Crepidula dilatata Lamarck, 1822: part 2: 25.

Crepipatella dilatata — Marincovich, 1973: 32, fig. 66 (synonymy).
Castellanos, 1990: 13, pl. 2, fig. 18 a—c.

Crepidula dilatata — Gallardo, 1977: 241-251 (development).
Gallardo, 1979: 215-226, fig. 1 (synonymy).

Crepidula dilatata — Hoagland, 1977: 372 (synonymy).

Crepidula fecunda Gallardo, 1979: 215-226, fig. 2.

DESCRIPTION. Shell to 72mm; irregularly oval to circular; marginal
apex, twisted to right side; smooth; colour often entirely white;
otherwise pinkish and marked externally with numerous fine radiat-
ing lines of purple brown and one central white stripe, interior
variously marked with pinkish purple, septum white; animal greyish
white, sides of foot, neck, head and mantle margin dark grey to black.

HABITAT. Common in pools and under rocks on rocky shores of
moderate exposure; under stones on sand in lower eulittoral of
sheltered bay; dredged on shell fragments to 15 m depth (to 18 m,
Dell, 1971); on pebbles in shallow tidal channels. Found in maxi-
mum abundance densely packed on subtidal rocks at depths of up to
2 m, in entrance of lagoon with strong tidal currents (station 11). At
Isla Chiloé Brattstr6m (1990) recorded it commonly in the lower
eulittoral zone. This species is a common epibiont on Aulacomya
atra and large barnacles (Marincovich, 1973; Gallardo, 1979).

RECORDS. Stations 1, 11, 12, 14, 15, 20. Elsewhere I. Lorenzo
(Peru) to Punta Arenas (Marincovich, 1973), possibly as far north as
Mazatlan (Mexico) (23°N) (Hoagland, 1977). Range: 12—53°S.

REMARKS. Gallardo (1979) has shown that two sibling species can
be recognized within this taxon, C. dilatata s.s. and C. fecunda, on
the basis of their larval development. In C. dilatata s.s. the veliger
larvae develop within the egg capsule, feeding on nurse eggs, and
hatch as juveniles, whereas in C. fecunda planktonic veligers hatch
from the capsule (Gallardo, 1977). Morphologically, the shells and
animals of these two species are too similar for reliable identifica-
tion, although C. dilatata is often white with a grey animal, whereas
C. fecunda has a pink shell of larger size and a more darkly
pigmented animal (Gallardo, 1979). No egg capsules were collected
during the present survey and the available material displays aspects
of both species. The large size attained (72 mm) and the generally

124

black coloration of the animal suggest C. fecunda, although the
shells are frequently white as in C. dilatata. At station 12 it was
found that specimens from beneath rocks had white, circular shells
and lightly-pigmented, predominantly yellow animals, whereas those
from the sides of rock pools had purple, oval shells and black
animals; it is not known whether these forms represent the two
species. Gallardo (1979) noted that the two were often sympatric in
the fjords of southern Chile, but that C. dilatata was the more
common. Large shells were moderately common in the ancient shell
middens on Isla Traiguén.

Trochita trochiformis (Born, 1778)
(Figure 3H, I)

Turbo trochiformis Born, 1778: 355.

Calyptraea (Trochita) trochiformis — Keen, 1971: 456, fig. 804.
Marincovich, 1973: 31-32, fig. 65.

Trochita radians (Lamarck, 1822) — Rehder, 1943: 42-43, fig. 1
(synonymy).

DESCRIPTION. Shell to 54 mm; circular with central apex; sculp-
ture of numerous sharp radial ribs; colour white, internally white
stained with dark brown; animal unpigmented.

HABITAT. Attached to undersides of stones closely appressed to
silty sediment in large tidal pool, in sublittoral fringe, sheltered from
wave action, common (station 14); also under stones on moderately
exposed rocky shores. In the north of Chile this species lives on
wave-exposed coasts (Marincovich, 1973), on both intertidal and
subtidal rock substrates (Canete & Ambler, 1992).

RECORDS. Stations 12, 14. Elsewhere Manta (Ecuador) to
Valparaiso (Rehder, 1943; Keen, 1971) and Canal Chacao (41°50°S;
Brattstrom & Johanssen, 1983). The present records extend the
confirmed range of this species. In addition, it has been mentioned
from Tierra del Fuego and the Magellan Strait (Carcelles &
Williamson, 1951), but confusion with the Magellanic species T.
pileus (Lamarck) is likely. Range: 1-46°S.

REMARKS. The worldwide distribution of the five recognized
living Trochita species shows a strong association with cold upwelling
systems or (in the Magellanic 7. pileus) with cold currents (Taylor &
Smythe, 1985). The present records extend the distribution of 7.
trochiformis considerably beyond the upwelling zones on the Chil-
ean coast, which extend only to 41°S (Brattstrom & Johanssen,
1983). Another peculiarity of these records is the unexpectedly
sheltered microhabitat under stones, and even resting on silt. Else-
where, this and the two most closely related species, T. spirata
(Forbes) and T: dhofarensis Taylor & Smythe, are found in the low
eulittoral and shallow sublittoral on rocky coasts exposed to strong
wave action (Marincovich, 1973; Taylor & Smythe, 1985; D.G.Reid
pers. obs. in Mexico and Cabo Verde). The intracapsular develop-
ment of T. trochiformis has been described by Caftete & Ambler
(1992). This edible species was occasionally found in shell middens
on Isla Traiguén.

Family LAMELLARIIDAE
Lamellaria ampla Strebel, 1906

Lamellaria ampla Strebel, 1906: 145-146, pl. 11, figs 70, 71.
Castellanos, 1990: 27, pl. 1, figs 9, 10.

DESCRIPTION. Animal 12 mm (to 32 mm, Strebel, 1906), shell 9

D.G. REID AND C. OSORIO

mm (to 19 mm, Strebel, 1906); shell fragile, transparent, auriculiform
with small, low spire and enlarged, oval aperture; shell entirely
covered by smooth mantle with oval outline and anterior notch,
broadly overlapping the foot; in life mantle is orange yellow with
indistinct dark markings; penis with conspicuous lateral flange and
small terminal filament.

HABITAT. Single animal dredged from 10-15 m, on bottom of silt
with scattered pebbles. Dredged from 40 m in Beagle Channel
(Linse, 1997).

RECORDS. Station 25. Elsewhere Beagle Channel (Strebel, 1906;
Linse, 1997). Range: 46—-55°S.

REMARKS. The identification of this single specimen is tentative,
and based on the form of the shell. Of the four species illustrated by
Strebel (1906) and one by Smith (1881), L. ampla is the only one
with a low-spired auriculiform shape as in the present example.
However, the form of the penis is somewhat different from that
outlined by Strebel (1906: pl. 11, fig. 70C). Marcus (1959: 85-86)
listed the names of 12 lamellariids reported from Chile and noted
that many were poorly known anatomically; this remains true and a
thorough revision is necessary. Members of the genus Lamellaria
prey upon ascidians.

Family RANELLIDAE

Argobuccinum (Argobuccinum) pustulosum ranelliforme
(King & Broderip, 1832)

(Figure 3M)

Triton ranelliformis King & Broderip, 1832: 347.

Argobuccinum ranelliforme — Smith, 1970: 462-466, pl. 39, figs 2,
4, 6, 9, pl. 40, figs 2, 6, 7, 10-12, textfigs 2b, 5.

Argobuccinum (Argobuccinum) pustulosum ranelliforme — Beu,
1985a: 56.

Argobuccinum (Argobuccinum) argus — Carcelles, 1954: 244-246,
figs 5, 6 (not Gmelin, 1791, which is the nominate subspecies).

DESCRIPTION. Shell to 82 mm: whorls rounded, two indistinct
varices per whorl; sculptured by low spiral ribs intersecting with
weak axial ribs to produce beaded sculpture, most pronounced on
spire whorls, becoming obsolete on last 1-2 whorls; colour cream
with chocolate brown ribs, interior white.

HABITAT. Common on beds of Mytilus in mid to low eulittoral
zone, and in zone of coralline red algae in sublittoral fringe, on
shores of moderate to strong wave exposure.

RECORDS. Stations 5, 14, 17. Elsewhere Caldera to Tierra del
Fuego (Carcelles, 1954; Smith, 1970). Range: 27—55°S.

REMARKS. This is a large, edible species, of which 277 tonnes
were collected nationally in 1997 (SERNAP, 1998). The diet con-
sists of crustaceans and echinoids (Smith, 1970), and the egg
capsules of the nominate subspecies from South Africa have been
described (Kilburn & Rippey, 1982: 75-76).

Family CERITHIOPSIDAE

Eumetula pulla (Philippi, 1845)
(Figure 7D)

Cerithium pullum Philippi, 1845: 66-67. Strebel, 1905b: 652-655,
pl. 23, fig. 40a—d.
Ataxocerithium pullum — Powell, 1951: 111-112, fig. I, no. 34

MOLLUSCA OF SOUTHERN CHILE

(radula), fig. N, no. 102 (protoconch) (synonymy). Castellanos,
1990: 8, pl. 2, figs 18, 21.
Eumetula pulla — Bouchet & Warén, 1993: 601.

DESCRIPTION. Shell to 8.8 by 3.5 mm (to 13 mm, Castellanos,
1990); narrowly elongate, thin-walled; spire whorls encircled by
three spiral rows of square nodules, aligned in axial rows, two spiral
ribs lacking nodules below periphery of last whorl; colour brown,
spiral rows of nodules darker.

HABITAT. Dredged from 10-15 m depth, on substrate of silt with
scattered pebbles and shells; uncommon. The species has been
reported from depths of 8 to 251-313 m (Powell, 1951). Other
members of the genus are known to live and feed on sponges, as do
most cerithiopsids (Houbrick, 1987), and this may be the typical
habitat of E. pulla also; one collection ‘in sponge’ was noted by
Melvill & Standen (1912).

RECORDS. Station 25 (1 dead, 2 live specimens). Elsewhere
Magellan Strait, Falkland Is and Burdwood Bank (Powell, 1951), so
that our records are the northernmost. Range: 46-54°S.

REMARKS. The more familiar genus Ataxocerithium has usually
been classified in the Cerithiidae, but was transferred to the
Cerithiopsidae by Houbrick (1987). Bouchet & Warén (1993) trans-
ferred this species to the cerithiopsid genus Eumetula on the basis of
radular characters.

Family MURICIDAE

Concholepas concholepas (Bruguiére, 1789)
(Figure 30)

Buccinum concholepas Bruguieére, 1789: 252.

Concholepas concholepas — Beu, 1970: 44, pl. 4, figs 10-12. Dell,
1971: 210-211. Marincovich, 1973: 35, fig. 73. Osorio, Atria &
Mann, 1979: 21-22, fig. 23. Kool, 1993: 173-176, fig. 7A-F.
DeVries, 1995: 286, figs 4, 6, 8, 9, 11, 19 (synonymy).

Concholepas concholepas concholepas — Stuardo, 1979: 5—38, pl. 1,
figs 1-8, pl. 3, figs 17, 23 (synonymy).

DESCRIPTION. Shell to 108 mm; body whorl greatly expanded to
produce limpet-like form; sculptured by coarse spiral ribs, imbri-
cated by raised axial growth lines; colour brown, interior white with
brown margin.

HABITAT. In rock crevices at top of calcareous red algal zone,
| lowest eulittoral, on strongly exposed coast. In central Chile and
| further north, adult populations are mainly subtidal, reaching depths
of 40 m (Rabi, Yamashiro & Quiroz, 1996), but the rarity of adults
_ in the littoral zone appears to be a consequence of exploitation by
humans. In reserves where this is prevented, large adults appear in
| the littoral zone and density may increase to as many as 1.6—4.3 per
m? (Castilla & Durén, 1985; Moreno, Lunecke & Lepez, 1986;
| Duran, Castilla & Oliva, 1987). Settlement occurs in the low
| eulittoral, and juveniles move upwards as growth occurs (Moreno,
|) Reyes & Asencio, 1993).

RECORDS. Station 16. Elsewhere I. Lobos de Afuera (Peru) to
| Cape Horn (DeVries, 1995). Range: 7-55°S.

| REMARKS. This large species supports the most important gastro-
| pod fishery in Chile (Castilla, 1982); the catch has declined from
| 21236 tonnes in 1987 to 3154 tonnes in 1997 (SERNAP, 1998) and
collection is now permitted for only a few days in the year. It is a
| common component of the ancient shell middens on Isla Traiguén.

125

Collection by fishermen continues in the study area, but the intensity
of exploitation is not known, nor to what extent this might influence
the absence of this species from the more accessible coasts of
moderate exposure. The egg capsules are cylindrical and stalked, 25
mm long; these have been described by Castilla & Cancino (1976)
and the planktotrophic development of the larvae by DiSalvo (1988).
This carnivorous species has a diet of barnacles, the ascidian Pyura,
Perumytilus and other molluscs (Castilla, Guisado & Cancino,
1979; Castilla & Duran, 1985) and is able to bore into its shelled prey
(Gruber & Carriker, 1990). As a top predator it has an important
influence on community structure, and where human collection is
prevented the cover of barnacles and Perumytilus declines signifi-
cantly (Moreno, Lunecke & Lepez, 1986). There is a large literature
on this species, reviewed by Rabi, Yamashiro & Quiroz (1996). The
taxonomic status of the population on the Juan Fernandez Islands,
described as the subspecies C. concholepas fernandezianus Stuardo,
1979, requires investigation.

Acanthina monodon (Pallas, 1774)
(Figure 3K, L)

Buccinum monodon Pallas, 1774: 33, pl. 3, figs 3, 4.

Acanthina monodon — Dell, 1971: 208-210 (synonymy).
Cernohorsky, 1977: 118 (synonymy). Osorio, Atria & Mann,
ISTO SA hie: 20"

Acanthina monodon monodon — Wu, 1985: 56-58, figs 13, 14, 24,
34, 52-58, 71 (radula, anatomy). Vermeij, 1993: 22.

Acanthina monodon unicornis (Bruguiére, 1789) — Vermeij, 1993:
22,

Acanthina crassilabrum (Lamarck, 1816) — Dell, 1971: 210 (syn-
onymy).

Acanthina monodon crassilabrum — Wu, 1985: 58-61, figs 15-17,
23, 35-37, 50, 51, 59, 71 (radula, anatomy).

DESCRIPTION. Shell to 57 mm; whorls rounded, spire pointed;
usually sculptured by 20-30 raised spiral cords, often imbricated by
raised axial growth lines; sculpture may be obsolete on body whorl,
or eroded; outer apertural lip sharp, or thickened and with internal
denticles, always with labral spine near anterior end of outer lip;
colour polymorphic: purple brown, white, orange or banded with
brown.

HABITAT. Eulittoral rocky shores, in lower barnacle zone and
Mytilus zone, in exposed and moderately sheltered situations. Found
at salinities down to 15 and 22%o.

RECORDS. Stations 1,5,7, 10, 12, 14, 15, 17, 20, 21, 22. Elsewhere
from about 22°S to Magellan Strait (Dell, 1971) and Tierra del
Fuego (Wu, 1985). Range: 22—55°S.

REMARKS. This was one of the most frequent intertidal gastro-
pods in the study area. Members of this species are carnivorous,
and small mussels are a major component of the diet (Moreno,
1995). The related Californian genus Acanthinucella feeds mainly
on barnacles, which are attacked either by using the labral spine to
prise or wedge open the opercular valves before inserting the
proboscis, or alternatively by boring through the valves by means
of the accessory boring organ and radula (Malusa, 1985; Perry,
1985). The egg capsules are small and flask-shaped, 15 mm in
length, and laid in batches in crevices on the shore (Wu, 1985: figs
52, 53). The shell is remarkably variable in shape and sculpture,
showing a much thicker, smoother shell with narrower aperture
and stronger marginal denticles (Fig. 3L) in sheltered habitats, in
contrast to a thinner, scaly shell in exposed situations (Fig. 3K).
Similar variation occurs over a geographical scale, and some

126

authors have distinguished a relatively smooth, northern species or
subspecies A. m. unicornis (Bruguiére, 1789) (= A. crassilabrum)
from the typical southern A. m. monodon with scaly spiral cords,
thinner shell and wider aperture (Dell, 1971; Wu, 1985; Vermeij,
1993). The two forms are said to overlap between 40 and 44°S and
have been recorded sympatrically (Dell,1971; Wu, 1985), although
characters evidently intergrade in this region (Cernohorsky, 1977;
Wu, 1985). The present samples extend the geographical range of
this overlap; both shape and sculpture vary such that no clear
distinction can usefully be made on the basis of these characters,
and the two forms are provisionally regarded as conspecific until
more evidence becomes available. As in the similar ocenebrine
muricid Nucella (e.g. Palmer, 1990), shell form might be a func-
tional phenotypic response to the presence of crab predators, from
which the snails are at greater risk on shores protected from wave
action. Possible correlation of shell form with abundance of preda-
tory crabs on local and geographical scales has not been
investigated in A. monodon. However, it is notable that several
intertidal Littorina species in the northern Atlantic show analogous
variation in shell characters over a geographical scale, with thin-
shelled forms present only at high latitudes where predatory crabs
are rare or absent, producing a stepped cline (Reid, 1996).

Trophon plicatus (Lightfoot, 1786)
(Figure 3N)

Trophon laciniatus (Martyn, 1784) — Strebel, 1904: 199-203, pl. 3,
figs 1-8 (non-binominal and therefore unavailable name).

Trophon (Stramonitrophon) laciniatus (Martyn, 1784) — Powell,
1951: 156.

Murex plicatus Lightfoot, 1786: 104.

Trophon plicatus — Cernohorsky, 1977: 117, fig. 18.

Trophon (Stramonitrophon) plicatus — Castellanos & Landoni, 1993:
5, pl. 1, figs 16-22.

Trophon (Stramonitrophon) lamellosa (Gmelin, 1791) — Dell, 1971:
212 (synonymy).

DESCRIPTION. Shell to 54 mm; fusiform with rounded whorls;
sculptured by prominent, lamellose varices (10-15 on last whorl),
each produced to a point on shoulder; colour white, eroded to
purplish grey, interior purple.

HABITAT. In sheltered tidal pool, just sublittoral, under stones on
silt; in rock pool with Mytilus in low eulittoral on moderately
exposed shore (station 14); dredged from 10-15 m on bottom of silt
with scattered pebbles and shells (station 25). To 88 m depth
(Powell, 1951).

RECORDS. Stations 14, 25. Elsewhere above 49°S to Tierra del
Fuego (Dell, 1971), extended northward by the present records.
Range: 46-54°S.

REMARKS. The brachiopod Magellania venosa was abundant in
the dredge samples from station 25, in which both this species and
Xymenopsis muriciformis occurred. A few of the brachiopods showed
boreholes in their shells, which may have been drilled by one or
other of these two muricids.

Xymenopsis muriciformis (King & Broderip, 1832)

(Figure 4A)

Buccinum muriciforme King & Broderip, 1832: 348.
Xymenopsis muriciformis — Dell, 1972: 38-39, figs 31, 32 (syn-
onymy). Cernohorsky, 1977: 118 (synonymy). Castellanos &

D.G. REID AND C. OSORIO

Landoni, 1993: 16, pl. 3, figs 39, 40. Pastorino & Harasewych,

2000: 43-52, figs 142, 45-49, 83-95, 105-106 (synonymy).
Xymenopsis decolor (Philippi, 1845) — Dell, 1971: 212-213.
Xymenopsis liratus (Gould, 1849) — Powell, 1951: 158-159.

DESCRIPTION. Shell to 26 mm; elongate fusiform, with rounded
whorls; sculptured by 13-15 rounded axial ribs, crossed by regu-
larly spaced incised lines (14-18 on last whorl); apertural lip not
thickened; colour white to purplish grey, interior white to purple.

HABITAT. Dredged from 7—15 m, on bottoms of gravel, or cobbles
on silt with brachiopods. Dell (1971) recorded this species from the
sublittoral to 18 m, and Powell (1951) from 17-170 m off the
Falkland Islands.

RECORDS. Stations 14, 22, 25. According to Dell (1971), from
about 45°S to Tierra del Fuego. Range: 45—54°S.

REMARKS. This genus shows a confusing diversity of shape and
sculpture. Strebel (1904) recognized an improbable 22 species in his
‘Trophon decolor’ group. This genus has recently been revised by
Pastorino & Harasewych (2000).

Xymenopsis subnodosus (Gray, 1839)
(Figure 4B)

Buccinum subnodosa Gray, 1839: 118.

Xymenopsis subnodosus — Pastorino & Harasewych, 2000: 55-56,
figs 96-103, 106.

Fusus cancellinus Philippi, 1845: 67. Philippi, 1846: 117-118,
Fusus pl. 3, fig. 2.

Xymenopsis cancellinus — Powell, 1951: 158.

DESCRIPTION. Shell 23 mm; elongate fusiform with shouldered
whorls; sculptured with rounded axial ribs (10 on last whorl),
crossed by close-set spiral cords, alternately large and small (24 on
last whorl); outer apertural lip thickened and denticulate within;
colour whitish, anterior canal tinged purple.

HABITAT. Single shell dredged from 5—15 m in sheltered bay, on
substrate of cobbles and shells.

RECORDS. Station 1. The type locality of F. cancellinus is the
Magellan Strait (Philippi, 1845). Range: 46-54°S.

REMARKS. Besides the holotype of Philippi’s F. cancellinus, this is
the only specimen known (Pastorino & Harasewych, 2000). The
denticulate lip is unlike other members of the genus.

Family BUCCINIDAE

Pareuthria fuscata (Bruguiére, 1789)
(Figure 4C)

Buccinum fuscatum Bruguiére, 1789: 282.

Pareuthria fuscata — Powell, 1951: 132 (synonymy).

Pareuthria plumbea (Philippi, 1844) — Powell, 1951: 133. Dell,
1971: 207-208 (synonymy). Castellanos, 1992: 13, pl. 3, fig. 37.

Pareuthria magellanica (Philippi, 1848) — Powell, 1951: 133 (syn-
onymy).

DESCRIPTION. Shell to 30 mm; elongate fusiform; spire whorls
sculptured with low, rounded axial ribs, becoming obsolete on last
1-2 whorls, otherwise smooth, but sometimes with indistinct spiral

CL

<_<

MOLLUSCA OF SOUTHERN CHILE

striae; aperture becoming somewhat thickened and lirate within in
largest specimens; colour dark bluish or purplish grey, aperture

purple.

HABITAT. Common inrock pools in Mytilus zone, among holdfasts,
under stones and in shell gravel, on moderately exposed shores; also
under stones on silt, in sheltered tidal pool, just sublittoral. Previous
authors have recorded this species mainly from the lower eulittoral
and shallow subtidal, but occasionally from depths of up to 16 m
(Powell, 1951) or 40 m (Strebel, 1905a). It was found in a survey of
Macrocystis holdfasts in the Beagle Channel (Ojeda & Santelices,
1984).

RECORDS. Stations 5, 12, 14. Elsewhere I. Chiloé to Magellan
Strait and Tierra del Fuego (Strebel, 1905b); Dell (1971) records this
species only as far north as 49°S. Range: 43-55°S.

REMARKS. The development of the axial ribs is variable, some
examples being almost smooth, and both Strebel (1905b) and Powell
(1951) distinguished three species on the basis of shell characters. A
critical revision is required to confirm whether these are but forms of
a single species (Dell, 1971).

Pareuthria powelli Cernohorsky, 1977
(Figure 4D)

Pareuthria rosea (Hombron & Jacquinot, 1854) — Powell, 1951:
133. Dell, 1971: 206-207 (synonymy) (junior primary homonym
of Fusus roseus Anton, 1838).

Pareuthria scalaris (Watson, 1882) — Powell, 1951: 134 (syn-
onymy). Cernohorsky, 1977: 109 (synonymy) (junior primary
homonym of Fusus scalaris Lamarck, 1816).

Pareuthria powelli Cernohorsky, 1977: 109, fig. 5 (synonymy).

DESCRIPTION. Shell to 17 mm; elongate fusiform; sculptured with
rounded axial ribs (9-12 on last whorl), crossed by fine spiral ribs
(about 21 on last whorl) becoming finer and sometimes obsolete
towards suture; apertural lip thin or (in thick-shelled specimens)
slightly thickened and indistinctly denticulate within; colour pinkish
purple or white.

HABITAT. Under stones on silt, in sheltered tidal pool, just
sublittoral; dredged from 7—9 and 10-15 m, on bottom of silt with
pebbles and shells, and on cobbles with encrusting calcareous algae.
Recorded from depths of up to 201 m (Powell, 1951).

RECORDS. Stations 7, 14, 22, 25. Elsewhere from 47°48’S in
northwest Patagonia (Watson, 1886: 203), 49°S to Magellan Strait
(Dell, 1971) and Tierra del Fuego (Strebel, 1905b), so that the
| present records are the most northerly. Range: 46—-55°S.

| REMARKS. The synonymy above follows Cernohorsky (1977). If
| this is correct, this is a variable species in shell thickness, promi-
| nence of sculpture, elongation of spire and colour, but a critical
reappraisal based on more material is necessary. Although some-
| what eroded, the protoconch of the present specimens appears to be
| only about two-thirds of the size of that of shells from the area
between the Falkland Islands and Patagonia.

| Glypteuthria meridionalis (Smith, 1881)
| (Figure 7E)

| Euthria meridionalis E.A. Smith, 1881: 29-30, pl. 4, fig. 6.
Euthria (Glypteuthria) meridionalis — Strebel, 1905b: 627-629, pl.
21, fig 11, 1la—d.

127

Glypteuthria meridionalis — Powell, 1951: 138. Dell, 1972: 36, fig.
10 (synonymy). Castellanos, 1992: 19, pl. 1, fig. 11.

DESCRIPTION. Shell 6.2 mm (to 9 mm, Smith, 1881); narrowly
fusiform; sculptured with rounded axial ribs (14 on last whorl),
crossed by spiral grooves (about 13 on last whorl); apertural lip
slightly thickened and smooth within; colour whitish.

HABITAT. Single specimen dredged from 10 m, on bottom of
cobbles, gravel and shells. To 38 m (Powell, 1951).

RECORDS. Station 14. Elsewhere recorded only to the south from
Portland Bay, St Andrew’s Sound to Magellan Strait (Smith, 1881)
and Tierra del Fuego (Strebel, 1905b). Range: 46-55°S.

Family NASSARIIDAE

Nassarius gayii (Kiener, 1834)
(Figure 4E)

Buccinum gayii Kiener, 1834: 71-72, pl. 21, fig. 79.

Nassarius gayi — Marincovich, 1973: 37, fig. 80. Castellanos, 1992:
23, pl. 2, fig. 18.

Nassarius gayii — Cernohorsky, 1975: 141-143, figs 44-49 (syn-
onymy). Cernohorsky, 1984: 34 (synonymy).

DESCRIPTION. Shell to 14 mm; broadly fusiform; sculptured with
axial ribs, becoming obsolete at end of last whorl, crossed by flat
spiral ribs (10-11 on last whorl), forming low nodules at their
intersections; apertural lip thickened and lirate within; colour pale
brown with dark brown spiral ribs, aperture white with brown
margin.

HABITAT. Among Mytilus holdfasts and on shell gravel, in rock
pools in low eulittoral on moderately exposed shores; more com-
monly dredged from 6—15 m, on bottoms of cobbles encrusted with
calcareous algae, on gravel, and on silt with shell fragments. At
Iquique in northern Chile Marincovich (1973) recorded this species
from the middle and lower intertidal, on the undersides of rocks in
gravel. At Isla Chiloé Brattstro6m (1990) found it commonly in the
lower eulittoral zone.

RECORDS. Stations 1, 5, 7, 11, 12, 14. Elsewhere I. Lobos de
Afuera (Peru) (Marincovich, 1973) to Puerto Rosario and Bahia
Tom (50°S, Smith, 1881) and Magellan Strait (Dall, 1909). The
southern limit is unclear; the species was common around 46°S in
the present study, Smith (1881) recorded seven immature specimens
(as ‘Nassa taeniolata Philippi, 1845’) from 50°S, and Dall (1909)
stated that the species ranged to the Magellan Strait (54°S), yet Dell
(1971) did not record it in extensive collections between 42 and
55°S. Range: 7-54°S.

Family VOLUTIDAE

Adelomelon ancilla (Lightfoot, 1786)
(Figure 4F, M)

Voluta ancilla Lightfoot, 1786: 137.

Adelomelon ancilla — Powell, 1951: 160-163. Castellanos &
Landoni, 1992: 8, pl. 1, fig. 1. Poppe & Goto, 1992: 21, 109-110,
pl. 35 (in part).

Adelomelon (Adelomelon) ancilla — Clench & Turner, 1964: 152-
154, pls 82, 83, 92-94 (synonymy, radula). Weaver & duPont,

128

1970: 102-103, fig. 20a—c, n, pl. 42A—C (synonymy). Osorio,
Atria & Mann, 1979: 19-20, fig. 19.

DESCRIPTION. Shell to 186 mm (Clench & Turner, 1964); large,
fusiform, with long narrow aperture; sculpture usually smooth but
for very fine growth lines, but apical whorls may bear fine spiral
striae and longitudinal ribs; apertural lip smooth, only slightly
thickened, columella with 2—4 sharp folds; colour cream with sparse
longitudinal zigzag brown lines, dark brown when covered by
periostracum, interior pale orange.

HABITAT. O-172 m (Powell, 1951), on sand bottoms to 310 m
(Poppe & Goto, 1992). The single dead shell in the present material
was dredged from 10 m on a gravel bottom.

RECORDS. Station 14. Elsewhere Magellan Strait to Falkland Is-
lands and southern Brasil (Clench & Turner, 1964), I. Chiloé (M.G.
Harasewych, pers. comm.). Range: 42—54°S.

REMARKS. This species is represented in the present collection by
a single dead shell, a small juvenile of 18 mm (Fig. 4F), clearly
assigned to the Volutidae by the large protoconch (with evidence of
a pointed calcarella, see Clench & Turner, 1964: pl. 93) 5.2 mm in
diameter. Identification to species has been based on the relatively
narrow first whorl of the teleoconch (indicating a tall narrow spire)
and on the teleoconch sculpture of spiral striae and slight axial folds.
Many specimens of A. ancilla are smooth at the apex, but this
sculptured form was described by Strebel (1906) as Voluta martensi,
subsequently synonymized by Clench & Turner (1964). An adult
shell of A. ancilla from the Falkland Islands is illustrated in Figure
4M. The taxonomy of this complex of large Magellanic volutes
remains confused. Powell (1951) pointed out the similarity of the
shells of A. ancilla and A. magellanica (Gmelin, 1791) and regarded
them as extremes of a single variable species. However, Clench &
Turner (1964) figured two very different radulae, and on this basis
transferred the latter to the new genus Odontocymbiola, distinct at
subfamilial level. Characters of the shell were not entirely diagnos-
tic, but that of O. magellanica was said to be broader and more solid,
and the protoconch apparently larger. This treatment was followed
by Weaver & duPont (1970). However, in the most recent mono-
graph of the family, Poppe & Goto (1992: 21, 109-110) have
rejected the evidence of the radular differences, and on the basis of
shell characters have synonymized these two, together with A.
paradoxa (Lahille, 1895). Clearly, additional anatomical informa-
tion is required to resolve this problem. The egg capsules are
attached to hard substrates; one illustrated by Strebel (1906: pl. 10,
fig. 52) is domed, 53 mm in diameter and contains seven embryonic
shells up to 14 mm in length; capsule and embryos have also been
figured by Carcelles (1944: pl. 3, figs 35-38).

Family TRITONIIDAE

Tritonia challengeriana Bergh, 1884

Tritonia challengeriana Bergh, 1884: 45-47, pl. 11, figs 16-19, pl.
12, figs 1-8 (anatomy, radula). Schrodl, 1996: 35, pl. 6, fig. 39
(synonymy).

DESCRIPTION. Animal up to 35 mm; oral veil with finger-like

processes; rhinophores with basal sheaths; body approximately

D.G. REID AND C. OSORIO

quadrilateral in cross section, along each lateral angle the mantle
forms a row of 15-21 branched pallial gills; colour white.

HABITAT. Among and beneath stones in pools in lowest eulittoral,
at top of red algal zone, on moderately sheltered shore. Recorded
from depths up to 18 m by Schrédl (1996), and dredged from 315 m
by the Challenger Expedition (Bergh, 1884). Members of this
family mostly feed on alcyonarians (Thompson & Brown, 1984).

RECORDS. Station 14. Elsewhere I. Chiloé to Magellan Strait
(Schroédl, 1996). Range: 42—-54°S.

Family FLABELLINIDAE
Flabellina falklandica (Eliot, 1907)

Coryphella falklandica Eliot, 1907: 354, pl. 28, fig. 7 (radula).
Flabellina falklandica — Schrédl, 1996: 37, pl. 7, fig. 44 (syn-
onymy).

DESCRIPTION. Animal up to 10 mm (to 40 mm, Schrédl, 1996);
rhinophores smooth; rhinophores and oral tentacles of similar size;
propodial tentacles present; dorsally with dense cerata, not arranged
in groups; colour transparent whitish with orange brown cerata.

HABITAT. On Macrocystis (as also noted by Schrédl, 1996) at 5—15
m depth, where the animals presumably graze on epiphytic hydroids.

RECORDS. Stations 1, 14. Elsewhere Seno Reloncavi to Magellan
Strait (Schrédl, 1996, 1997). Range: 42—-54°S.

Family SIPHONARITDAE

Siphonaria (Talisiphon) lessonii Blainville, 1827
(Figure 4G, H)

Siphonaria lessonii Blainville, 1827: 296, pl. 61, fig. 2, 2a.

Siphonaria (Pachysiphonaria) lessoni — Hubendick, 1946: 21-22,
fig. 4, pl. 1, figs 1-3 (anatomy). Olivier & Penchaszadeh, 1968:
469-491, pl. 1, textfigs. 2, 3, 5 (radula, anatomy). Dell, 1971:
214-215 (synonymy).

Pachysiphonaria lessoni — Powell, 1951: 181.

Siphonaria (Talisiphon) lessoni — Morrison, 1963: 7 (synonymy).
Marincovich, 1973: 42, fig. 95.

Siphonaria tristensis Leach, 1824 — Strebel, 1907: 170-172, pl. 3,
figs 31-33.

DESCRIPTION. Shell to 20 mm; high (rarely low) conical to cap-
shaped limpet, apex at about one third shell length from posterior
margin, posterior slope sometimes concave, basal outline asym-
metrically oval, with slight projection on right side (corresponding
to pneumostome opening of animal); sculpture smooth or with slight
radial ribs; colour pale with numerous fine dark brown to black
radial lines, interior dark brown with pale margin where exterior
dark rays show through.

HABITAT. Abundant on rocks on sheltered and exposed shores; in
upper eulittoral together with barnacles and Nodilittorina araucana,
extending into zones of Nacella and Mytilus, and often attached to

Fig.4 A. Xymenopsis muriciformis (20 mm). B. Xymenopsis subnodosus (23 mm). C. Pareuthria fuscata (30 mm). D. Pareuthria powelli (17 mm). E.
Nassarius gayii (12 mm). F. Adelomelon ancilla (juvenile; 18 mm). G, H. Siphonaria (Talisiphon) lessonii (15 mm). I. Chilina patagonica (15 mm). J, K.
Malletia magellanica (19 mm, 14 mm). L. Mulinia edulis (60 mm). M. Adelomelon ancilla (adult; 200 mm; Falkland Islands). N. Felaniella inconspicua
(18 mm). O. Zygochlamys patagonica (juvenile;17 mm). (All specimens from study area except M; all NHM collection).

an

ee

eas

cal
=|
ae
oO
Z
~
aa)
ae
=
—
ie)
Y
ce
e)
<
oO
22)
5)
S|
S|
fe)
=

130

these shells; on sheltered shores it is common even on silty rock
surfaces; found at seawater salinities down to 20%o, but also frequent
at mouths of streams where salinity must fall to very low levels at low
tide or during rain. In northern Chile it is reported to be common in the
barnacle zone and also in tidepools throughout the eulittoral (Guiler,
1959a; Marincovich, 1973), and is also common over a wide tidal
range in the Magellan Strait (Benedetti-Cecchi & Cinelli, 1997).
Together with lottiid limpets of the genus Scurria, Siphonaria lessonii
is one of the most abundant herbivores of the mid-intertidal zone of
southern Chile, reaching densities of 1317 per m* and grazing
principally on Jridaea fronds (Jara & Moreno, 1984). In a marine
reserve this species occured mainly in the mid and upper eulittoral;
outside the reserve, where the competing dominant herbivore
Fissurella picta is removed by human collection, S. lessonii was
larger and extended its zonation to low tide level (Godoy & Moreno,
1989). A detailed study of the ecology of this species has been made
in the Mar del Plata, Argentina (Olivier & Penchaszadeh, 1968).

RECORDS. Stations 1, 6, 8, 10, 11, 12, 14, 20, 21, 25. Elsewhere
Paita (Peru) to Magellan Strait and Tierra del Fuego (Hubendick,
1946; Marincovich, 1973). Range: 5—54°S.

REMARKS. This is one of the most abundant molluscs in the upper
intertidal zone in the study area. It is a pulmonate limpet, recognized
by the pneumostome of the mantle to the right side of the foot. It
should not be confused with Scurria parasitica which is a symmetri-
cally oval limpet, with broader dark rays, and white interior with
brown apex; these two limpets frequently occur together in beds of
Mytilus.

Family CHILINIDAE

Chilina patagonica Sowerby, 1874
(Figure 41)

Chilina patagonica Sowerby, 1874: Chilina sp. 11, pl. 3, fig. 11.
Strebel, 1907: 166-168, pl. 8, figs 98, 102, 105a—c. Haeckel,
1911: 89-136, pls 7-11 (anatomy). Stuardo, 1961: 22 (synonymy).
Castellanos & Gaillard, 1981: 34, pl. 5, figs 15, 16 (synonymy).

DESCRIPTION. Shell to 16 mm; cylindrical with produced spire,
apex usually eroded away; shell thin and covered by thick
periostracum; columella with one prominent fold; colour yellow
brown with more or less distinct axial lines of dark brown which
form four conspicuous spiral bands of chevrons or irregular axial
marks, columella white.

HABITAT. Common among stones, Enteromorpha and on mud, in
sheltered brackish inlet (salinity 5%oc) near freshwater stream, also
among saltmarsh vegetation on sheltered shores of Laguna San
Rafael. Strebel (1907) recorded this species from marine fjords, and
Davenport et al. (1995) found it commonly in streams and saltmarsh
vegetation in the Laguna San Rafael. In Estero Reloncavi Bratt-
str6m (1990) recorded Chilina bulloides Sowerby from similar
low-salinity habitats.

RECORDS. Stations 28, 31. Elsewhere Puerto Montt to I. Picton
(Strebel, 1907). Range: 41—-55°S.

REMARKS. There are about 36 nominal species of Chilina recorded
from Chile (Stuardo, 1961; Ituarte, 1997), mostly from freshwater
habitats. Shells are variable in form and coloration, making identifi-
cation difficult. A review of the Chilean species based on anatomical
and radular characters is in progress (Valdovinos & Stuardo, 1995).
Meanwhile, the identification of the present material has been based

D.G. REID AND C. OSORIO

on comparison with dry syntypes (NHM) and on the interpretations
of Strebel (1907) and Castellanos & Gaillard (1981). There are
several anatomical accounts of Chilina species (Haeckel, 1911;
Brace, 1983; Ituarte, 1997) and they are of evolutionary interest as
primitive basommatophoran pulmonates.

Class Bivalvia
Family NUCULIDAE

Nucula (Nucula) pisum Sowerby, 1833
(Figure 7G)

Nucula pisum Sowerby, 1833a (January): 6, pl. 3, fig. 23. Sowerby,
in Broderip & Sowerby, 1833 (March): 198. Dall, 1909: 250.
Soot-Ryen, 1959: 12, pl. 1, figs 1, 2.

Linucula pisum — Dell, 1964: 144, pl. 2, figs 7, 8 (synonymy).
Ramorino, 1968: 183-185, pl. 1, fig. 4, pl. 4, fig. 2. Osorio &
Bahamonde, 1970: 187. Maxwell, 1988: 89.

Nucula (Linucula) pisum — Bernard, 1983: 10 (synonymy).

Nucula (Nucula) pisum — Villarroel & Stuardo, 1998: 129-131.

DESCRIPTION. Shell to 3.3 mm (to 5.4 mm, NHM); rounded
trigonal; hinge taxodont, 9-14 anterior teeth, 5 posterior (Soot-
Ryen, 1959); sculpture of strong concentric striae towards margin in
larger shells, crossed by apparent radial lines throughout (these are
subsurface prisms within outer shell layer) that crenulate the margin,
radials on escutcheon are finer and divergent from the rest; colour
fawn, stained by ferruginous deposit at umbos, interior nacreous.

HABITAT. Dredged from 10-15 m depth, among cobbles with
encrusting calcareous red algae. Recorded from depths of 5-60 m on
coarse or fine sand by Soot-Ryen (1959). Villarroel & Stuardo
(1998) reported a maximum density of 848 per m? on sandy mud at
51-80 m in the Bahia de Valparaiso, and gave an overall depth range
of 8-200 m; from the same locality Ramorino (1968) recorded
densities of up to 4650 per m?.

RECORDS. Station 7 (2 specimens). Elsewhere, the extent of the
range is uncertain. Soot-Ryen (1959) gave Valparaiso (the type
locality) and recorded specimens from 41—43°S. Dall (1909) gave
‘Valparaiso to San Blas, Chile’ (the latter presumably Estrecho San
Blas, 51°S, but mis-quoted as San Blas, Argentina, a locality at
40°S, by Carcelles & Williamson, 1951, Soot-Ryen, 1959, and
Osorio & Bahamonde, 1970). Carcelles & Williamson (1951) also
included the Magellanic region and Falkland Islands. However, Dell
(1964) noted possible confusion with Nucula falklandica Preston,
1912, in these southern parts of the range. Range: 25—54°S.

REMARKS. Maxwell (1988) and Villarroel & Stuardo (1998) have
discussed the generic allocation of this species.

Family MALLETIIDAE

Malletia magellanica (Smith, 1875)
(Figure 4J, K)

Solenella magellanica Smith, 1875: 118-119.

Malletia magellanica — Smith, 1881: 39, pl. 5, fig. 3, 3a. Carcelles,
1950: 74, pl. 3, fig. 65. Carcelles & Williamson, 1952: 324.
Osorio & Bahamonde, 1970: 188. Villarroel & Stuardo, 1998:
155-156.

MOLLUSCA OF SOUTHERN CHILE

DESCRIPTION. Shell to 31 mm (38 mm, Smith, 1881); ovate, more
or less pointed posteriorly, delicate; surface smooth, with growth
lines; periostracum thick, glossy; external ligament; hinge taxodont,
8-9 anterior teeth, 17—20 posterior teeth (but sometimes distorted
when umbos are eroded); pallial sinus large, but distant from pallial
line, so that meeting of the two is bluntly rounded; colour yellow
brown to dark or olivaceous brown, interior white.

HABITAT. Dredged from 5-15 m depth on silt bottom, abundant in
Laguna San Rafael at salinity of 15%. Smith (1881) recorded this
species from 4-58 m depth on mud in the northwestern Magellan
Strait.

RECORDS. Stations 25, 29, 30. Elsewhere Islas Otter (52°S) and
Caleta Cockle (Smith, 1881). Carcelles & Williamson (1951) give
the Magellanic region and Kerguelen Islands. Range: 46—52°S.

REMARKS. Six nominal species of Malletia are recorded from
southern Chile (Osorio & Bahamonde, 1970), and the chief distin-
guishing features are shell outline, numbers of hinge teeth and the
form of the pallial sinus (Soot-Ryen 1959; Dell, 1964; Ramorino,
1968; Villaroel & Stuardo, 1998). Both the hinge and pallial line of
the present specimens are identical to those of the syntypes in the
NHM, but the largest syntype (and the figures of Smith, 1881, and
Carcelles, 1950) shows a markedly more rostrate posterior. How-
ever, two of the three syntypes are less rostrate, and overlap with the
most elongate examples of the present collections (e.g. Fig. 4K).
Dell (1964) has observed variation in the development of the
rostrum in another Malletia species. The majority of the samples
from the Laguna San Rafael are, nevertheless, more oval in outline,
and additional material is necessary to confirm our identification.

Family MYTILIDAE

Mytilus edulis chilensis Hupé, 1854
(Figure 5D, E)

Mytilus chilensis Hupé, 1854: 309-310, malacologia pl. 5, fig. 4.
Reid, 1974: 179-184. Osorio, Atria & Mann, 1979: 25-26, fig. 27.

Mytilus edulis chilensis —Soot-Ryen, 1959: 24-25. Dell, 1964: 174.
Osorio & Bahamonde, 1970: 191. Dell, 1971: 170-171.

Mytilus edulis Linnaeus, 1758 — Soot-Ryen, 1955: 19-22, pl. 1, figs
1, 2, textfigs 1, 2, 10, 11 (anatomy, synonymy). Olsson, 1961:
113, pl. 12, fig. 6. McDonald, Seed & Koehn, 1991: 323-333.

DESCRIPTION. Shell to 105 mm; beaks terminal, pointed; shell
solid, but thinner and translucent in brackish habitats (Fig. 5D); 3-
4 small tooth-like folds within umbos; chalky resilial ridge adjacent
to ligament pitted by minute pores; posterior adductor and retractor
scars continuous; radial sculpture absent; periostracum thick, glossy,
with hairs in very small specimens; colour blue or sometimes pale
brown, overlaid by black or brown periostracum, eroded at umbos;
interior nacreous, silvery blue.

HABITAT. An abundant species in a wide range of intertidal habi-
tats; on exposed shores it forms dense beds from the middle to lower
eulittoral on rocks and cliffs (size increases towards lower levels and
in more sheltered situations); on sheltered shores it occurs also
among stones and boulders; in estuaries and lagoons it forms clumps
on hard substrates in muddy situations, occurring adjacent to fresh-
water streams; in a brackish inlet (station 28) the species was still
common on the muddy shore at a salinity of 5%c; in the Laguna San
Rafael it occurred intertidally and was also dredged from 5S—10 m, in
clumps on mud and gravel, at salinities of 15%o. Mytilus edulis

131

chilensis is an important component of the ecosystem of the Laguna,
where its occurrence and zonation have been described by Daven-
port et al. (1995). Soot-Ryen (1959) notes that although the species
is mainly intertidal, a few living specimens have been found at 25 m
depth. Ecological studies of this species include those by Miranda &
Acuna (1979) in the Magellan Strait and by Stotz (1981) in an
estuary near Valdivia.

RECORDS. Stations 5, 6, 10, 12, 13, 14, 15, 17, 20, 21, 22, 24, 25,
26, 28, 29, 30, 31. Elsewhere, Soot-Ryen (1959) reports specimens
from Iquique to Magellan Strait. The species is evidently scarce in
central and northern Chile, for it is not reported in ecological or
faunistic studies of this region (Marincovich, 1973; Romo & Alveal,
1977; Ruiz & Giampaoli, 1981). Range: 20-54°S.

REMARKS. Mytilus edulis has a wide, bipolar distribution in the
north Atlantic and southern South America. Traditional morpho-
logical comparison of shells has failed to detect consistent differences
between the northern and southern groups (Soot-Ryen, 1955),
although they have often been recognized as distinct subspecies on
account of their geographical separation (Soot-Ryen, 1959). More
recently, multivariate morphometric analysis has shown that South
American mussels are intermediate in shell shape between the
northern M. edulis and M. trossulus Gould, 1850, but since allozyme
analysis has revealed a closer similarity to northern M. edulis, this
name has been tentatively applied to the southern forms also
(McDonald etal., 1991). Reid (1974) described the digestive system
and claimed that Chilean material differed from a published account
of northern M. edulis, but this requires confirmation. The presence
of this species in South America is apparently not the result of recent
human introduction from the north Atlantic, since there are some
genetic differences and, furthermore, the species is present in pre-
Colombian shell middens in Argentina (McDonald et al., 1991). The
modern information on classification and evolution of Mytilus has
been reviewed by Gosling (1992) and Seed (1992). Until the geo-
graphical relationships of M. edulis are resolved, we retain subspecific
distinction for the Chilean form. Well preserved specimens of M.
edulis chilensis have a smooth surface, but care must be taken to
distinguish eroded specimens from the longitudinally ribbed
Aulacomya atra and Perumytilus purpuratus, with which they may
occur on the same shore. Choromytilus chorus is externally similar
to M. edulis chilensis, but reaches much larger size and is mainly
found subtidally. Another large mytilid, Perna perna (Linnaeus,
1758), has been recorded from Concepcion to the Magellan Strait
(Carcelles & Williamson, 1952, as Chloromya achatinus; see Soot-
Ryen,1955: 30); this is similar in shape to M. edulis chilensis, or
slightly more elongate, externally brown or green, internally purp-
lish or pink, with a wide separation between the posterior adductor
and retractor scars. Mytilus edulis chilensis is an important edible
species, of which the annual harvest was 13358 tonnes in 1997
(SERNAP, 1998) and is also cultivated commercially.

Choromytilus chorus (Molina, 1782)
(Figure 5F)

Mytulus chorus Molina, 1782: 202.

Choromytilus chorus — Soot-Ryen, 1955: 31, pl. 2, figs 7, 8, textfig.
5 (synonymy). Soot-Ryen, 1959: 26. Olsson, 1961: 115, pl. 12,
fig. 10. Osorio & Bahamonde, 1970: 191. Osorio, Atria & Mann,
1979: 24-25, fig. 26. Bernard, 1983: 18 (synonymy).

DESCRIPTION. Shell to 186 mm (to 300 mm, Suchanek, 1985);
beaks terminal, pointed; shell solid; single tooth-like fold within
umbo of right valve, and corresponding groove in left valve; resilial

132

ridge adjacent to ligament not pitted by pores; posterior adductor
and retractor scars continuous; radial sculpture absent; periostracum
very thick, glossy; colour blue to purple, overlaid by black
periostracum, often eroded at umbos; interior nacreous, silvery blue.

HABITAT. No living specimens were found during the present
study. Elsewhere, this mussel has been recorded in a variety of
habitats; on the exposed rocky coasts of southern Chile it occurs in
the sublittoral, and also in the low eulittoral in the absence of
collection by humans (Moreno, 1995); it is also frequent in estuar-
ies, sometimes on sedimentary substrates, and at reduced salinities
(monthly average high tide salinity of 20%c, Navarro, 1988). A
depth range of 4-20 m was given in a study of growth and reproduc-
tion by Lozada, Rolleri & Yanez (1971).

RECORDS. Stations 9 (midden material), 10 (fresh valves). Else-
where Pacasmayo (Peru) to Tierra del Fuego (Soot-Ryen, 1955).
Range: 7—-56°S.

REMARKS. Superficially similar in shape to the smaller Mytilus
edulis chilensis, this species is distinguished by its single hinge tooth
and resilial ridge without pits. It is the largest and most esteemed of
the edible mussels of the Chilean coast, and consequently is exten-
sively collected; in 1997 the catch was 527 tonnes. Despite a
considerable literature on the culture and laboratory behaviour of
this species, there is little information about its natural ecology. At
present, populations are almost entirely sublittoral throughout the
region, although where shores are protected from human activity
large numbers appear in the lower eulittoral (Moreno, 1995). This
mussel is a major component of the large shell middens on Isla
Traiguén; the age of these deposits is not known, but intact shells
occurred at depths of up to 5 m in the eroding face of the midden at
Station 9. In addition, fresh shells were found at Station 10, presum-
ably recently discarded by fishermen. The species was an important
item of food for the indigenous people of the Chonos Archipelago,
who collected it by diving, and it is possible that the present
restricted distribution is a consequence of exploitation over a long
period of time (P.J. Curry, pers. comm.). In the north of Chile the
species is likewise common in middens, but is now locally extinct,
although whether this is a result of human activity is unclear
(Viviani, 1979).

Aulacomya atra (Molina, 1782)
(Figure 5A, B)

Mytulus ater Molina, 1782: 202-203.

Aulacomya ater — Soot-Ryen, 1955: 33-34, pl. 1, fig. 6, textfigs 17,
18 (synonymy). Soot-Ryen, 1959: 26-27. Olsson, 1961: 116, pl.
14, fig. 9 (synonymy). Osorio & Bahamonde, 1970: 192.
Marincovich, 1973: 8, fig. 3. Osorio, Atria & Mann, 1979: 22-24,
fig. 24. Bernard, 1983: 17-18 (synonymy).

Aulacomya ater ater — Dell, 1964: 175-177 (synonymy). Dell,
WOW ie AL.

Aulacomya atra — Cazzaniga, 1994: 110.

DESCRIPTION. Shell to 154 mm (to 200 mm, Suchanek, 1985);
beaks terminal, pointed; shell solid; single broad tooth-like fold
within umbo of left valve, and corresponding groove in right valve;

D.G. REID AND C. OSORIO

resilial ridge adjacent to ligament not pitted by pores; posterior
adductor and retractor scars broadly continuous; strong radial ribs
present; periostracum thick, glossy; shells less than 40 mm white,
overlaid by yellow to brown periostracum; larger shells purple to
dark blue, overlaid by black periostracum, eroded at umbos; interior
nacreous, silvery to purple.

HABITAT. Adults of this species were only found commonly on
the shore at two relatively inaccessible sites on an exposed rocky
shore and a cliff (Stations 13, 17), where they formed dense clumps
at the top of the calcareous red algal zone in the sublittoral fringe.
Elsewhere, juveniles (to 40 mm) were found in small numbers
among the byssus of dense beds of Mytilus edulis chilensis, and
under stones in the mid to lower eulittoral on moderately exposed
and sheltered shores, but these individuals evidently died before
reaching large size. On the sheltered shores of the southernmost
Estero Elefantes and Golfo Elefantes, adults were occasionally
found on the shore; some were freshly dead, with the byssus
detached from the substrate, whereas others were only superficially
attached; empty valves were common on the beaches in this region.
It appears therefore that there may be considerable sublittoral
populations in this area, from which living and dead mussels are
washed up on the shore. The presence of beds of Macrocystis near
the shore made dredging here difficult, but a living adult was
dredged from 7—9 m (station 22), and a few others were brought up
in the holdfasts of the kelp from 5—15 m. Salinities of 15—20%o
were recorded at the southern sites. Elsewhere, occasional living
specimens have been recorded from 40 m at I. Chiloé (Soot-Ryen,
1959) and from 79 m in the Falkland Islands (Dell, 1964). It was
common in the lower intertidal and subtidal at Iquique
(Marincovich, 1973) and found in the mid to lower intertidal at Isla
Chiloé (Brattstrém, 1990). This species does occur also in more
sheltered situations, as in the Estero Castro, where a natural mussel
bank was studied between depths of 4-9 m, but accumulation of
mud caused mortality (Lozada, 1968).

RECORDS. Stations 1, 5, 13, 14, 17, 20, 22, 25. Elsewhere Callao
(Peru) to Magellan Strait (Soot-Ryen, 1955). Range: 12-56°S.

REMARKS. Although almost universally referred to as Aulacomya
ater in the recent literature, the name should be corrected to A. atra
since, as pointed out by Cazzaniga (1994), the adjectival specific
name should agree in gender with the feminine generic name. This
species is easily distinguished from all other large mussels in the
region by its radially ribbed shell; specimens less than 40 mm in
length could be confused with Perumytilus purpuratus, but at this
size the shells are yellow to pale brown, with less than 17 ribs,
whereas those of P. purpuratus are purplish with a brown to black
periostracum and have twice as many ribs and a more rounded
outline. Like the preceding species, A. atra is a large mussel that is
collected commercially in large quantities; the catch in 1997 was
6597 tonnes (SERNAP, 1998). It is unclear to what extent the
present scarcity of intertidal populations is a result of
over-exploitation. This species is the major component of the large
shell middens on Isla Traiguén; these are of unknown age, but some
are up to 5 m in height. Fresh valves at some sites suggests that
collection continues.

Fig.5 A, B. Aulacomya atra (juvenile 26 mm; adult 80°mm). C. Perumytilus purpuratus (39 mm). D. Mytilus edulis chilensis (thin-shelled form from low
salinity habitat, station 29; 45 mm). E. Mytilus edulis chilensis (thick-shelled form from higher salinity habitat, station 22; 71 mm). EF. Choromytilus
chorus (186 mm). G. Cumingia mutica (25 mm). H. Tawera gayi (18 mm; Portland Bay and Port Rosario, Patagonia, ‘Alert’ Expedition, NHM
1879.10.15.60). I. Venus antiqua (67 mm). J. Retrotapes exalbidus (86 mm). K. Tagelus (Tagelus) dombeii (82 mm). L. Hiatella solida (11 mm). M.
Ensis macha (129 mm; Punta Arenas, Magellan Strait, NHM 1868.7.1.22). N—P. Bankia (Bankia) martensi (N, shell 7.2 mm; O, pallet 30 mm; P, whole
animal, length 50 mm approx.). (All specimens from study area except H and M; all NHM collection).

a

MOLLUSCA OF SOUTHERN CHILE

134
Perumytilus purpuratus (Lamarck, 1819)
(Figure SC)

Modiola purpurata Lamarck, 1819: 113.

Brachidontes purpuratus — Soot-Ryen, 1955: 45, pl. 4, fig. 18,
textfig. 30. Soot-Ryen, 1959: 28. Dell, 1971: 172. Bernard, 1983:
18 (synonymy).

Perumytilus purpuratus — Olsson, 1961: 117, pl. 12, fig. 1, pl. 14,
fig. 1, la, 1b (synonymy). Osorio & Bahamonde, 1970: 192.
Marincovich, 1973: 9, fig. 6. Osorio, Atria & Mann, 1979: 24, fig.
DS.

DESCRIPTION. Shell to 50 mm; beaks almost terminal, rounded;
shell solid; several small tooth-like crenulations within umbo; resilial
ridge adjacent to ligament not pitted by pores; posterior adductor
and retractor scars continuous; fine radial ribs present, crenulating
margin; periostracum thick, glossy; shell white, purplish posteriorly,
overlaid by dark brown to black periostracum, eroded at umbos,
interior nacreous, silvery to purplish brown.

HABITAT. Frequent inarange of intertidal habitats: under stones in
mid to upper eulittoral on sheltered boulder shores, forming partly
buried accretions on upper shore of muddy shingle beaches, and
sometimes together with Mytilus edulis chilensis in dense beds of
small shells at top of Mytilus zone in mid-eulittoral on exposed
rocky coasts. The species is especially abundant in sheltered habitats
where there is a moderate freshwater input from streams or runoff,
and was found at salinities down to 15—20%o. This is a strictly
intertidal species (Soot-Ryen, 1959; Dell, 1971), but can be found
throughout the intertidal zone in both southern and northern parts of
its distribution (Marincovich, 1973; Brattstr6m, 1990; Benedetti-
Cecchi & Cinelli, 1997). In central and northern Chile P. purpuratus
is the dominant organism in the mid-eulittoral on both sheltered and
exposed shores, forming dense beds (Guiler, 1959a; Romo & Alveal,
1977; Ruiz & Giampaoli, 1981; Santelices, 1991; Alvarado &
Castilla, 1996). The great abundance of this species may be a
consequence of the removal of its major predator, the edible
Concholepas concholepas, by humans (Castilla & Duran, 1985).

RECORDS. Stations 1, 5, 6, 10, 11, 12, 14, 17, 20, 21, 22, 25, 26.
Elsewhere Yasila near Paita (Peru) (Olsson, 1961) to Magellan Strait
(Soot-Ryen, 1955; Benedetti-Cecchi & Cinelli, 1997). Range: 5—
54°S.

REMARKS. Discrimination from the only other ribbed mussel,
Aulacomya atra, has been described earlier. Perumytilus purpuratus
is seldom found in pure colonies, but almost always together with
Mytilus edulis chilensis. When shells are well preserved, the two are
easily separated by the fine radial ribs of the former. When shells are
severely eroded (as is often the case in habitats of low salinity), the
crenulated margin and purplish shell of P. purpuratus differentiate it
from the blue, smooth-margined shells of M. edulis chilensis. The
proportions of these two species in the mytilid zone appear to vary
with exposure, tidal level and salinity. On exposed shores and at
lower levels P. purpuratus is replaced by M. edulis chilensis.
Perumytilus purpuratus becomes more frequent on sheltered shores,
and wherever there is limited freshwater inflow. However, in estua-
rine areas of the lowest salinity (S—15%c, stations 28, 29, 30, 31) it is
absent and here the presumably more euryhaline M. edulis chilensis
occurs alone.

D.G. REID AND C. OSORIO
Family PECTINIDAE

Zygochlamys patagonica (King & Broderip, 1832)
(Figure 40)

Pecten patagonicus King & Broderip, 1832: 337.

Chlamys patagonica — Soot-Ryen, 1959: 29. Osorio, Atria & Mann,
1979: 28, fig. 30. Waloszek, 1984: 207-276, pls 1-3, pls 5-9
(synonymy).

Chlamys patagonica patagonica — Beu, 1985b:1—11, pl. 1, figs 1-4.

Chlamys (Zygochlamys) patagonica — Dell, 1964: 178-179. Osorio
& Bahamonde, 1970:193.

Zygochlamys patagonica — Waller, 1991: 28-30, pl. 2, figs 13, 14.

Chlamys patriae Doello Jurado, 1918 — Soot-Ryen, 1959: 29-31.
Osorio & Bahamonde, 1970: 193.

Chlamys amandi Hertlein, 1935 — Soot-Ryen, 1959: 29-31, pl. 1,
figs 7, 8. Osorio & Bahamonde, 1970: 193.

DESCRIPTION. Shell 16 mm (to 90 mm, Waloszek, 1984); a round,
almost equivalved scallop; sculptured by 30-32 (22-41, Waloszek,
1984) primary radial ribs (excluding ears), with secondary ribs
between, crossed by fine concentric laminae which may form
minute scales on ribs or in interspaces; right (lower) valve pink,
orange or brown, with darker ribs; left valve white with pink to
orange ribs; interior white, flushed with pink or purple.

HABITAT. Single small specimen dredged from 10-15 m, among
cobbles with encrusting calcareous red algae, in sheltered bay.
Although occasionally taken in the shallow sublittoral, the typical
habitat of this species is in deeper water, 25—100 m in the vicinity of
I. Chiloé (Soot-Ryen, 1959), 15 to over 200 m off eastern Patagonia
and the Falkland Islands (Dell, 1964; Waloszek & Waloszek, 1986).

RECORDS. Station 7. Elsewhere I. Chiloé to Magellan Strait, Tierra
del- Fuego and Cape Horn (Waloszek, 1984). Range: 42—56°S.

REMARKS. A detailed taxonomic study of this and other Magellanic
scallops has revealed that the three species discriminated by Soot-
Ryen (1959) are extremes of the range of a single taxon with variable
microsculpture (Waloszek, 1984). The generic assignment has been
discussed by Beu (1985b) and Waller (1991). This species is fished
commercially in the Magellan Strait (Osorio et al., 1979) and in
1997 the catch was 2598 tonnes (SERNAP, 1998). During the
present study fossil specimens of an additional pectinid species,
Chlamys vitrea (King & Broderip, 1832), were found in a clay cliff
of an eroding raised beach on the southwestern shore of Isla Rojas.
This species has a more delicate shell, transparent when young, with
less distinct, rounded ribs and in life is associated with Macrocystis
(Waloszek, 1984: pl. 4, fig. 5).

Family UNGULINIDAE

Felaniella inconspicua (Philippi, 1845)
(Figure 4N)

Diplodonta inconspicua Philippi, 1845: 53. Hupé, 1854: 357,
malacologia pl. 8, fig. 4. Soot-Ryen, 1959: 43 (synonymy). Herm,
1969: 115, pl. 3, figs 5—7. Osorio & Bahamonde, 1970: 199. Dell,
eile N73.

Fig.6 Scanning electron micrographs of Polyplacophora. A, C. Leptochiton (Leptochiton) medinae (C, detail of girdle spicules). B, D. Ischnochiton
(Ischnochiton) stramineus (D, detail of girdle scales). E. Ischnochiton (Haploplax) pusio, detail of girdle scales. F. Chiton (Amaurochiton) magnificus
bowenii, detail of girdle scales. (All specimens from study area; NHM collection).

MOLLUSCA OF SOUTHERN CHILE

é
¢

cs vi i)
VAG G5 BY Bed { ae :

«

4 45 /
dtd

D>

135

136

? Diplodonta phillippii Hupé, 1854: 357-358, malacologia pl. 8, fig.
5.
Felaniella inconspicua — Bernard, 1983: 30.

DESCRIPTION. Shell 19 mm (to 32 mm, Soot-Ryen, 1959); orbicu-
lar, thin-shelled, only moderately inflated; sculpture of fine concentric
growth lines; the larger of two cardinal teeth in each valve bifid;
pallial line entire, not indented, adductor muscle scars almost equal;
colour white.

HABITAT. Dead valves dredged from 10—15 m depth, on bottoms
of gravel, coarse sand and cobbles; scarce. This species has been
recorded intertidally in sand, and living to depths of 36 m (Soot-
Ryen, 1959) and 65 m (Ramorino, 1968).

RECORDS. Stations 7, 14. Elsewhere Tocopilla to Golfo Corcovado
(Soot-Ryen, 1959). Range: 22—-49°S.

REMARKS. ‘The four valves in the present material are more deli-
cate and less inflated than typical shells of F: inconspicua. In this
they correspond with the description of Diplodonta phillippii from
Isla Chiloé by Hupé (1854); although this was regarded only as a
form of D. inconspicua by Soot-Ryen (1959), the status of the two
taxa deserves further investigation.

Family GALEOMMATIDAE

Lasaea miliaris (Philippi, 1845)
(Figure 7H, I)

Kellia miliaris Philippi, 1845: 51.
Lasaea miliaris — Soot-Ryen, 1959: 51. Dell, 1971: 174-175, pl. 1,
fig. 9, pl. 2, figs 3, 4. Castellanos, 1979: 136.

DESCRIPTION. Shell to 2.8 mm; orbicular, inflated, umbos promi-
nent; sculpture of very fine, regular growth lines; colour pink to
purplish red.

HABITAT. In empty barnacles in barnacle zone of upper eulittoral,
on exposed and moderately exposed shores. At Isla Chiloé a similar
(possibly identical) form, identified as L. petitiana Recluz, was
abundant in the barnacle zone (Brattstrom, 1990).

RECORDS. Stations 12, 14. Elsewhere Magellan Strait, Tierra del
Fuego, Falkland Is (Soot-Ryen, 1959; Dell, 1971). Range: 46—-56°S.

REMARKS. Members of this genus are common components of
the crevice fauna on rocky shores throughout the world. The
taxonomy of this genus of minute bivalves was unsatisfactory
when based only on rather variable shell features (Dell, 1971).
However, it has now been thrown into further confusion by the
discovery that most of the ‘species’ are highly polyploid asexual
lineages, with nonplanktotrophic, brooded development (O Foighil
& Smith, 1995). The present material has been compared with
syntypes in NHM, but the specific name is used only in the sense
of a morphospecies.

Family CARDITIDAE

Carditella tegulata (Reeve, 1843)
(Figure 7J)

Cardita tegulata Reeve, 1843: sp. 48, pl. 9, fig. 48. Reeve, 1844:
194.
Carditella tegulata — Lamy, 1922: 354-355, textfig. Carcelles &

D.G. REID AND C. OSORIO

Williamson, 1951: 334. Dell, 1964: 194, textfig. 3, no. 8 (syn-
onymy). Osorio & Bahamonde, 1970: 197. Bernard, 1983: 34.

DESCRIPTION. Shell to 7.5 mm; subtrigonal, solid; sculptured by
11-13 strong radial ribs, crossed by fine regular concentric ribs,
producing lamellate appearance on radials; margin coarsely
crenulated by radial ribs; small external ligament; colour whitish
with yellow brown periostracum.

HABITAT. Dredged from 10 m on bottom of cobbles, gravel and
coarse sand; uncommon. From 50 m at Valparaiso (Reeve, 1843).

RECORDS. Station 14 (5 specimens). Elsewhere Callao (Peru) to
Magellan Strait (Carcelles & Williamson, 1951). Range: 12-54°S.

REMARKS. This species is closely similar to Carditella pallida
Smith, 1881. Smith (1881) distinguished his species by the 14-15
ribs and almost centrally placed umbos, and these characters are
confirmed by our examination of the two syntypes (NHM, type
locality Valparaiso). In comparison, the three syntypes of C. tegulata
(NHM, type locality Port Rosario, south Patagonia) have 11-12
coarser ribs and slightly more anterior umbones. However, these
differences are slight. The four specimens in the present material
resemble C. tegulata in sculpture, but the ribs are slightly less
pronounced, 11—13 in number, and the shell outline is closer to that
of C. pallida. Our specimens are therefore intermediate in form, as
well as in locality, between these two taxa and suggest possible
clinal variation between them. Dell (1964) emphasized the close
relationship of this pair of species; further investigation is desirable.
Care must be taken to distinguish this species from Carditopsis
flabellum, with which it occurs. Our familial assignment of both
these species follows Chavan (1969). The specimens figured by
Soot-Ryen (1959: pl. 1, fig. 11) and Marincovich (1973: fig. 9) are
not C. tegulata, but belong to the C. naviformis (Reeve, 1843) group,
with more oblong shells (see Dell, 1964).

Family CONDYLOCARDITDAE

Carditopsis flabellum flabellum (Reeve, 1843)
(Figure 7K)

Cardita flabellum Reeve, 1843: sp. 47, pl. 9, fig. 47. Reeve, 1844:
194.

Carditopsis flabellum — Lamy, 1922: 360. Soot-Ryen, 1959: 40.
Ramorino, 1968: 204-206, pl. 2, fig. 2, pl. 6, figs 2, 3. Bernard,
1983: 35.

Carditopsis flabellum flabellum — Dell, 1964: 195, textfig. 3, nos 2,
3 (synonymy). Osorio & Bahamonde, 1970: 197. Linse, 1997: 59,
pl. 2, figs 5-8, textfig. 12f.

DESCRIPTION. Shell to 4.3 mm; subtrigonal, solid; sculptured by
13-14 strong rounded radial ribs, crossed by concentric, slightly
lamellose, growth lines; margin coarsely crenulated by radial ribs;
no external ligament, internal resilium between beaks; colour whit-
ish with yellow brown periostracum and black staining around
umbos.

HABITAT. Dredged from 10 m on bottom of cobbles, gravel and
coarse sand, and from 10—15 m on cobbles encrusted with calcareous
red algae; uncommon. Ramorino (1968) found densities of up to 155
per m? in the Bahia de Valparaiso, on sandy mud at depths of 65-145
m. Reported from 25-135 m in the Magellan Strait (Linse, 1997).

RECORDS. Stations 7, 14 (3 specimens). Elsewhere Callao (Peru)
to Magellan Strait (Soot-Ryen, 1959; Dell, 1964; Linse, 1997).
Range: 12—54°S.

MOLLUSCA OF SOUTHERN CHILE

REMARKS. This species is extremely similar in external appear-
ance to Carditella tegulata, which occurs in the same habitat.
Carditopsis flabellum flabellum is recognized by the absence of an
external ligament which, although small, is clearly visible behind
the beaks of Carditella tegulata. A subspecies, Carditopsis flabel-
lum malvinae (d’Orbigny, 1846), occurs in the Falkland Islands
(Dell, 1964).

Family MACTRIDAE

Mulinia edulis (King & Broderip, 1832)
(Figure 4L)

Mactra edulis King & Broderip, 1832: 335.

Mulinia edulis — Soot-Ryen, 1959: 66. Osorio & Bahamonde, 1970:
205. Bernard, 1983: 40 (synonymy).

Mulinia byronensis (Gray, 1838) — Soot-Ryen, 1959: 65-66.

Mulinia sp. Osorio, Atria & Mann, 1979: 33-34, fig. 40.

DESCRIPTION. Shell to 77 mm; large, solid, rounded-trigonal,
moderately inflated; sculpture smooth with strong concentric growth
lines; hinge with large internal ligament in deep chondrophoral pit,
cardinal teeth fused to form inverted V below beak; colour white,
texture chalky, with yellow brown periostracum (usually eroded
except near margin).

HABITAT. Living specimens partly buried in soft mud near low
water level, on sheltered shores in brackish conditions (salinities
15-20 %o), sometimes near freshwater stream outflows. This species
is found at low tide in the Magellan Strait (Urban & Tesch, 1996) and
on intertidal and subtidal sandbars, in sediments with a high silt and
clay content, in the estuaries of southern Chile (Jaramillo, Mulson &
Navarro, 1985; Gonzalez & Jaramillo, 1991).

RECORDS. Stations 20, 22, 25. Elsewhere Callao (Peru) to Magellan
Strait (Soot-Ryen, 1959). Range: 12-54°S.

REMARKS. The taxonomy of this genus in southern South America
is confused, as a result of variability in shell outline, and a revision
is required (Soot-Ryen, 1959; Herm, 1969; Osorio et al., 1979). The
present specimens are most similar in shape to M. byronensis which
is, however, probably only a form of the widespread M. edulis.
Shells were present in the extensive shell middens of Isla Traiguén.

Family PHARIDAE

Ensis macha (Molina, 1782)
(Figure 5M)

Solen macha Molina, 1782: 203-204.

Ensis macha — Carcelles, 1950: 81, pl. 5, fig. 92. Soot-Ryen, 1959:
67. Osorio & Bahamonde, 1970: 206. Osorio, Atria & Mann,
1979: 34-35, fig. 41. Bernard, 1983: 41 (synonymy). von Cosel,
1990: 301.

DESCRIPTION. Shell estimated 130 mm (to 211 mm, NHM); thin-
shelled, very elongate, slightly concave dorsally, margins parallel,
ends truncated and gaping, beaks at extreme anterior end; sculpture
smooth, with concentric growth lines; ligament external, hinge with
1 cardinal in right valve, 2 in left, 1 posterior lateral in each valve;
colour white with strong yellow brown periostracum, eroded away
at umbos, internally white.

HABITAT. Single broken dead shell dredged from 5-15 m on

137

bottom of cobbles, mud and shell. This is acommon deep-burrowing
species found in fine sediments in shallow water in southern Chile,
and has been reported at 2-10 m depth in sand and silt (Urban, 1994,
1996) and living in coarse sand at 13 m (to Soot-Ryen, 1959).
Ramorino (1968) found juveniles in sand at 26 m in the Bahia de
Valparaiso.

RECORDS. Station 1. Elsewhere Caldera to Magellan Strait (Soot-
Ryen, 1959; Osorio & Bahamonde, 1970). Range: 27-54°S.

REMARKS. This is a commercially important edible species; the
1997 catch was 5361 tonnes (SERNAP, 1998). The family was more
familiar by the name Cultellidae, but Pharidae has priority (von
Cosel, 1990).

Family SEMELIDAE

Cumingia mutica Sowerby, 1833
(Figure 5G)

Cumingia mutica Sowerby, 1833b: 34. Soot-Ryen, 1959: 65. Olsson,
1961: 372, pl. 66, fig. 4. Osorio & Bahamonde, 1970: 205. Keen,
1971: 257, fig. 658. Dell, 1971: 176-177. Bernard, 1983: 46
(synonymy).

DESCRIPTION. Shell to 25 mm (to 30 mm, NHM); outline rounded
anteriorly and produced posteriorly; sculpture of closely-spaced
concentric growth lines with microscopic radial striae between;
hinge with internal part of ligament attached to large cup-shaped
chondrophore, cardinal teeth weak, strong lateral teeth in right valve
only; colour white, with brown periostracum (worn away except
near margin).

HABITAT. Dead valves dredged from 5—15 m on bottoms of cob-
bles, gravel and coarse sand; uncommon. Other authors have recorded
this species intertidally on sandy mud (Sowerby, 1833b; Soot-Ryen,
1959) and to a depth of 18 m (Dell, 1971).

RECORDS. Stations 1, 7, 14. Elsewhere Guayaquil (Ecuador) to I.
Wellington (Soot-Ryen, 1959; Dell, 1971). Range: 2-49°S.

Family PPAMMOBIIDAE

Tagelus (Tagelus) dombeii (Lamarck, 1818)
(Figure 5K)

Solen dombeii Lamarck, 1818: 454.

Tagelus dombeii — Soot-Ryen, 1959: 61-62. Osorio & Bahamonde,
1970: 204. Osorio, Atria & Mann, 1979: 32, fig. 37. Bernard,
1983: 48 (synonymy).

Tagelus (Tagelus) dombeii — Olsson, 1961: 351, pl. 62, figs 1, 1a, 5
(synonymy).

DESCRIPTION. Shell to 82 mm (to 90 mm, Olsson, 1961); narrowly
elongate, dorsal and ventral margins almost parallel, ends rounded,
valves gaping at either end, beaks central; sculpture smooth with
fine concentric growth lines; hinge weak, 2 cardinal teeth in right
valve, 1 in left; colour purple to brown with paler rays radiating from
umbo, chalky white when eroded, covered by strong brown perio-
stracum, often eroded at umbos, interior white to purple.

HABITAT. Dead shells common on sheltered beaches of silty sand.
This is a deep-burrowing bivalve found in sand and silt (Urban,
1994, 1996). Its distribution is mainly intertidal, with records down
to depths of 16 m (Soot-Ryen, 1959) and 37 m (Ramorino, 1968).

D.G. REID AND C. OSORIO

MOLLUSCA OF SOUTHERN CHILE

RECORDS. Stations 1, 6. Elsewhere El Lagartillo (Panama) to
Golfo Corcovado (Olsson, 1961; Soot-Ryen, 1959), extended south-
ward by the present record. Range: 8°N-46°S.

REMARKS. This is a commercial edible species; the 1997 catch
was 4316 tonnes (SERNAP, 1998).

Family VENERIDAE

Venus antiqua King & Broderip, 1832
(Figure 51)

Venus antiqua King & Broderip, 1832: 336. Fischer-Piette, 1975:
24-25 (synonymy).

Protothaca antiqua — Carcelles, 1950: 80, pl. 5, fig. 86.

Ameghinomya antiqua — Soot-Ryen, 1959: 54—S5, pl. 3, figs 22, 23.
Osorio & Bahamonde, 1970: 202. Dell, 1971: 175-176 (syn-
onymy). Osorio, Atria & Mann, 1979: 29-30, fig. 32. Bernard,
1983: 51 (synonymy).

Protothaca antiqua antiqua — Herm, 1969: 123, pl. 10, figs 2-4, pl.
11, figs 1, 2.

Venus antiqua antiqua — Osorio, Frassinetti & Bustos, 1983: 49-56,
figs 1-11 (synonymy).

DESCRIPTION. Shell to 76 mm; rounded, inflated; sculpture of
numerous strong radial ribs, crossed by fine concentric lamellae, the
lamellae more strongly raised on anterior and posterior slopes;
lunule in front of beaks outlined by deeply incised line; hinge strong,
three cardinal teeth in each valve; margin crenulated internally;
pallial sinus small; colour cream to pale brown, sometimes marked
by tessellated or fine radial chevron pattern in small shells, interior
cream.

HABITAT. On silty sand at low water on sheltered beach; common
embedded in gravel under stones in rock pools in low eulittoral on
moderately sheltered rocky shore; abundant in gravel in shallow
channel with strong tidal currents, 1.5 m depth at high tide; dredged
from 7—15 m depth on bottoms of cobbles and silt; found living at
salinities down to 15—20%c. This is a dominant member of intertidal
and shallow subtidal soft-bottom communities in southern Chile,
and is typically found shallowly buried in mixed silty and stony
substrates (Urban, 1994) and in gravelly muddy sand (Clasing,
Brey, Stead, Navarro & Asencio, 1994). It has been recorded down
to depths of 18-25 m (Soot-Ryen, 1959; Dell, 1971) and 65 m
(Ramorino, 1968).

RECORDS. Stations 1, 7, 14, 15, 22, 25, 26. Elsewhere Callao
(Peru) to Tierra del Fuego (Soot-Ryen, 1959; Osorio et al., 1983).
Range: 12—S5°S.

REMARKS. This species shows variability in shell outline and
degree of development of sculpture. It is an important edible species
and is the major component of ‘almejas’ (including other large
venerid bivalves), of which the 1997 harvest was 12475 tonnes,
largely from Isla Chiloé (SERNAP, 1998). It is an abundant compo-
nent of shell middens on Isla Traiguén and freshly dead shells
indicate that collection for food continues on a small scale in the
area. We do not advocate use of the subspecific epithet, since the
description of the only ‘subspecies’ (P. antiqua tongoyensis Herm,
1969) does not conform to the requirements of either geographical

139

or stratigraphic separation from the typical form. We follow
Fischer-Piette (1975) in assigning this species to the genus Venus,
and we confirm that the date of publication of the original descrip-
tion by King & Broderip is 1832.

Retrotapes exalbidus (Dillwyn, 1817)
(Figure 5J)

Venus exalbida Dillwyn, 1817: 179.

Samarangia exalbida — Carcelles, 1944: 287, pl. 12, figs 93, 94.
Carcelles, 1950: 80, pl. 5, fig. 87.

Eurhomalea exalbida — Soot-Ryen, 1959: 59. Dell, 1964: 219
(synonymy). Osorio & Bahamonde, 1970: 203. Fischer-Piette &
Vukadinovic, 1977: 106—107 (synonymy). Osorio, Atria & Mann,
1979: 30-31, fig. 34.

Retrotapes exalbida — del Rio, 1997: 80-82, figs 22, 23, 41.

DESCRIPTION. Shell to 85 mm (to 106 mm, NHM); large, heavy
venerid; sculptured by raised concentric lamellae, regularly-spaced
1—2 mm apart on young shells, becoming crowded on larger shells,
lunule in front of beaks outlined by groove; internal margin smooth;
hinge with 3 strong cardinal teeth in each valve; colour cream to
brownish, interior white.

HABITAT. Two dead valves dredged from 10-15 m on bottoms of
cobbles, gravel and coarse sand. It has been found living in the low
intertidal zone in the Magellan Strait (Urban & Tesch, 1996),
Carcelles (1950) gave a depth range of S—115 m, and Dell (1964)
recorded specimens from 147 m in the Falkland Islands.

RECORDS. Stations 7, 14. Elsewhere I. Chiloé to Cape Horn
(Carcelles & Williamson, 1951; Fischer-Piette & Vukadinovic,
1977). Range: 42—56°S.

REMARKS. The shell outline and regularity of sculpture are both
variable in this species (Carcelles, 1944; Dell, 1964). This species
has recently been assigned to the new genus Retrotapes by del Rio
(1997); we note that since the Latin noun fapes is masculine,
Retrotapes should take the same gender. It is an edible species, a
component of ‘almejas’ (see V. antiqua).

Tawera gayi (Hupé, 1854)
(Figure 5H)

Venus gayi Hupé, 1854: 337, malacologia pl. 6, fig. Sa—c.

Clausinella gayi—Carcelles, 1944: 287, pl. 13, figs 97, 98. Carcelles,
1950: 80, pl. 5, fig. 88. Soot-Ryen, 1959: 58, pl. 3, figs 26, 27
(synonymy). Herm, 1969: 126, pl. 12, figs 7, 8.

Tawera gayi — Osorio & Bahamonde, 1970: 203. Dell, 1971: 175.
Fischer-Piette & Vukadinovic, 1977: 39-40, fig. 8 (synonymy).
Bernard, 1983: 53 (synonymy).

DESCRIPTION. Shell to 12mm (to 39mm, Carcelles, 1944); rounded
outline; sculptured by fine concentric ridges, of which a few become
irregular and anastomose on anterior and posterior slopes, lunule in
front of beaks outlined by groove; inner margin crenulated; hinge
with three strong cardinal teeth in each valve; colour cream to pale
brown, interior white.

HABITAT. Two dead valves dredged from 10-15 m on bottoms of
cobbles, gravel and coarse sand. Recorded from the tidal zone and

| Fig.7 Scanning electron micrographs of Gastropoda and Bivalvia. A. Jothia coppingeri. B. Puncturella (Puncturella) conica. C. Nodilittorina araucana.
D. Eumetula pulla. E. Glypteuthria meridionalis. ¥. Homalopoma cunninghami. G. Nucula (Nucula) pisum. H, 1. Lasaea miliaris. J. Carditella tegulata.
K. Carditopsis flabellum flabellum. (All specimens from study area; NHM collection).

140

down to 40 m by Soot-Ryen (1959), 65 m (Ramorino, 1968), 5—10
m (Urban & Tesch, 1996) and to 219 m (Linse, 1997).

RECORDS. Stations 7, 14. Elsewhere Coquimbo to Tierra del
Fuego (Fischer-Piette & Vukadinovic, 1977). Range: 30-56°S.

Family HIATELLIDAE

Hiatella solida (Sowerby, 1834)
(Figure SL)

Saxicava solida Sowerby, 1834: 88-89.

Hiatella solida—Soot-Ryen, 1959: 67-68. Olsson, 1961: 425, pl. 77,
fig. 6, 6a. Dell, 1964: 224—226 (synonymy). Osorio & Bahamonde,
1970: 206. Dell, 1971: 177-178. Marincovich, 1973: 14—15, fig.
22. Bernard, 1983: 59. Gordillo, 1995: 193-195, fig. 5.

DESCRIPTION. Shell 12 mm (to 46 mm, Dell, 1964); irregularly
elongate rectangular, often distorted by nestling habit, sometimes
with a strong keel running from umbo to postero-ventral margin,
gaping posteriorly; sculpture of irregular growth lines; hinge often
weak, ligament external; colour white with thin periostracum.

HABITAT. Single specimen in Macrocystis holdfast at 3-5 m depth.
This species has been reported from a wide range of habitats. In the
Beagle Channel, it is found attached by byssus on rocky shores,
among Mytilus clusters, nestling in sand and gravel at low water and
subtidally in Macrocystis holdfasts (Gordillo, 1995). On hard rock
substrates it adopts a nestling habit in crevices, but on soft rock and
on calcareous shells (e.g. of Concholepas concholepas) it becomes
a shallow borer (Gallardo & Osorio, 1978). In the Falkland Islands
it has been recorded from the sublittoral fringe to depths of over 350
m (Dell, 1964).

RECORDS. Station 22. Elsewhere the distribution is unclear owing
to taxonomic uncertainty, but Soot-Ryen (1959) gives Ecuador to
Cape Horn, and Olsson (1961) has a record from the Pearl Islands
(Panama). Range: 8°N—56°S.

REMARKS. As discussed by Dell (1964) the taxonomy of this
genus is confused, because of variation in shell outline and hinge
development. Although he concluded that H. antarctica (Philippi,
1845) was a synonym of H. solida, others have maintained the two
as distinct taxa (Osorio & Bahamonde, 1970; Bernard, 1983).
During this study abundant fossil specimens (up to 36 mm), were
found in the eroding clay cliff of a raised beach on the southwestern
side of Isla Rojas.

Family TEREDINIDAE

Bankia (Bankia) martensi (Stempell, 1899)
(Figure SN—P)

Teredo (Xylotrya) martensi Stempell, 1899: 240, pl. 12, figs 24-27.
Bankia martensi — Turner, 1966: 109, pl. 48, fig. D, pl. 61, figs A—
C, pl. 62, figs A, B (synonymy).

D.G. REID AND C. OSORIO

Bankia (Bankia) martensi — Soot-Ryen, 1959: 70. Osorio &
Bahamonde, 1970: 207. Osorio, Atria & Mann, 1979: 36, fig. 44.
Bernard, 1983: 62.

DESCRIPTION. - Animal to approx. 150 mm, shell to 8 mm, pallets to
35 mm; body elongate, worm-like, enclosed in calcareous tube
bored into wood; shell (Fig. SN) at anterior end, reduced, file-like
surface, white with thin brown periostracum; pair of calcareous
pallets protect siphons at posterior end; pallet (Fig. 50) composed of
central stalk with numerous cone-like elements with fringed border,
each cone extending laterally as a point.

HABITAT. A wood-boring species, abundant in logs in the inter-
tidal zone, recorded down to salinity of 20%c. Reported from the
intertidal to a depth of 55 m (Soot-Ryen, 1959).

RECORDS. Stations 1, 7, 20, 25. Elsewhere Seno Reloncavi to
Magellan Strait (Soot-Ryen, 1959). Range 41—54°S.

DISCUSSION

Ecology and distribution of molluscs in the study
area

During our survey we recorded a total of 62 species of molluscs
during shore collecting and dredging from depths of 5 to 15 m. For
a region at this latitude (46°S) this is not a large number. In part, this
paucity may be explained by the pronounced salinity gradient along
the length of the fjord system. Within the Laguna San Rafael, subject
to meltwater from the San Rafael Glacier, we recorded surface
salinities of 14—15%c (to 17%c, Davenport et al., 1995), and found
but three mollusc species. In the higher and more variable salinity
regime of the Golfo Elefantes (surface salinity 15—21%o, at 15 m
almost certainly greater) the records rose to 18 species. Only in the
main Estero Elefantes were fully marine habitats present (27—33%o)
and in such habitats our total was 56 species. The most euryhaline of
the species was Mytilus edulis chilensis, occurring abundantly at
almost all stations, down to a salinity of 5%o (station 28). Other
euryhaline species were those found on the shore (and therefore
subject to the low surface water salinity) in the Golfo Elefantes:
Plaxiphora aurata, Nacella magellanica, Siphonaria lessonii,
Perumytilus purpuratus, Aulacomya atra, Mulinia edulis and Bankia
martensi. The only species restricted to areas of low salinity were
Chilina patagonica (5—15%c) and Malletia magellanica (14-21%c).

A striking aspect of this molluscan fauna was the dominance of
mytilid bivalves in a range of intertidal and shallow sublittoral
habitats. Most abundant was the euryhaline Mytilus edulis chilensis,
forming dense beds in the mid to lower eulittoral on both exposed
and sheltered shores, and on exposed shores providing a microhabitat
for the limpets Scurria parasitica and Siphonaria lessonii. Peru-
mytilus purpuratus generally occurred with Mytilus edulis chilensis
on the upper shore, and was most common in sheltered sites with
freshwater influence. Aulacomya atra also formed dense beds in the
low eulittoral and sublittoral on wave-exposed coasts, and was
probably common in the sublittoral of shelted sites (where

Fig. 8 Compilation of known geographical ranges for the molluscs recorded in our survey of the Laguna San Rafael, Golfo Elefantes and Estero Elefantes
(see text for sources; 46°S latitude of survey area indicated as LSRNP). Superimposed are the biogeographical provincial boundaries of Brattstr6m &
Johanssen (1983). Antarctic species are those extending south of the Antarctic convergence; Magellanic species are those found only between Cape Horn
and the northern limit of the transitional zone (56—30°S); Peruvian species are those found only within the Peruvian Province and transitional zone (2—
46°S); widespread species are those found in both Magellanic and Peruvian Provinces and (in two cases) extending north of the equator. Arrows indicate
ranges extending beyond the limits shown. Species occurring in the littoral zone and sublittoral fringe are indicated by dots. Note that Xymenopsis

cancellinus is a junior synonym of X. subnodosus

MOLLUSCA OF SOUTHERN CHILE 141

Transitional
Magellanic
<é Prov.» <—. Peruvian Province ——_»
50°S 40°S 30°S 20°S 10°S 0°

lothia corpiagert 4
Puncturella conica

e Lasaea miliaris —_—__
Nacella mytilina _—_——
Margarites violacea Se
Lamellaria ampla __

e Pareuthria powelli ——
Glypteuthria meridionalis —esy
Eumetula pulla —_—_—_—_—

e Trophon plicatus ——
Xymenopsis cancellinus ————
Malletia magellanica —cmomeeat

e Xymenopsis muriciformis —eepe

omalopoma cunninghami

e Pareuthria fuscata See
Xygochlamys patagonica
Retrotapes exalbidus
Adelomelon ancilla —_—

e Tritonia challengeriana Sa
Flabellina falklandica ————

Magellanic species

Nacella magellanica
e Chilina patagonica
e Bankia martensi

Leptochiton medinae

ee ae |
'
i
bee See
e Tonicia atrata a
e Fissurella oriens
e Fissurella picta an eanE EERE
e Fissurella nigra a

aie rape eis BD eee a EE
Tawera gayi :
e Argobuccinum pustulosua———_————— ——

Ensis macha —OoeoOY...ne
Nucula pisum
e Acanthina monodon eS a ETS Te
e Mytilus edulis chilensis ——_—_—_----
e Ischnochiton stramineus —_—_—_—_—Olel?.....
e Aulacomya atra
e Venus antiqua oe Ee ee
e Ischnochiton pusio
e Tonicia chilensis

ee
a
e Scurria ceciliana
Carditelia tenulata BL i a aeREee
Carditopsis Rabelhare i a nt
e Mulinia edulis —_—__—__—___—_—
e Chiton magnificus :
e Crepidula dilatata SS ee
e Diloma nigerrima a
Cierarayens chorus —————————————————_—_—_—_—

e Concholepas concholepas
e Tegula atra jp eS a

~n
o
—
3)
vo
ou
~n
a)
3
oO
_
ou
nH
Oo
=

e Nassarius gayii a
e Siphonaria lessonii —_—_——s— a ae = _eeeeeeeeeeeeeeeeeee
e Perumytilus purpuratus
Hiatella solida
Tagelus dombeii :
Felaniella inconspicua eee Se
Cumingia mutica
c e Chiton granosus ee a a ae
.S | e Scurria parasitica a
5 | e Nodilittorina araucana Seannnnl EnEnERNARRREREERnaaieeemieniaeinEEaiEaeEinEEin
5 | ¢ Chaetopleura peruviana [a7 Gana cea
Q4 | e Trochita trochiformis

142

dense Macrocystis beds made sampling difficult). The large mussel
Choromytilus chorus was not found alive, but probably occurred in
the shallow sublittoral.

The giant kelp Macrocystis provides a habitat for a characteristic
association of molluscs in the Magellanic region. During our survey
we found Leptochiton medinae, Plaxiphora aurata, Fissurella oriens,
Aulacomya atra and Hiatella solida in the holdfasts, and a similar
fauna has been recorded from holdfasts further south, in the Beagle
Channel (Ojeda & Santelices, 1984; but also including Pareuthria,
Xymenopsis and a cerithiopsid). However, on the kelp lamina we
found molluscs to be very scarce, and only occasional specimens of
Nacella mytilina, Fissurella oriens and Flabellina falklandica were
encountered. In the Beagle Channel the kelp lamina supports a larger
community of molluscs, of which the most characteristic are Nacella
mytilina, Margarella violacea, Chlamys vitrea (King & Broderip,
1832) and Gaimardia trapesina (Lamarck, 1819) (King & Broderip,
1832; Castilla, 1985; Waloszek, 1984; D.G. Reid, pers. obs.).

During our survey we did not neglect to examine trawled sedi-
ment and washings from intertidal algae for the presence of small
molluscs. Nevertheless, no small rissoiform gastropods were found.
This is surprising in view of the 23 species, many of them intertidal,
belonging to the families Eatoniellidae, Cingulopsidae and Rissoidae
that were recorded from southern Chile and Tierra del Fuego by
Ponder & Worsfold (1994). Possibly the low and fluctuating salinity
of large parts of the Estero Elefantes fjord system might be con-
nected with the apparent scarcity of small gastropod species in the
shallow-water habitats that we examined.

Biogeographical affinities of the molluscs

Many different authors have discussed the marine biogeographical
‘provinces’ of the west coast of South America, basing their classi-
fications on various taxonomic groups, ecological systems and
depth ranges. Those who have referred specifically to molluscs
include Dall (1909), Carcelles & Williamson (1951), Stuardo (1964),
Dell (1971), Marincovich (1973) and Viviani (1979), and their
conclusions have been summarized, and their data enlarged, by
Brattstr6m & Johanssen (1983). In general there is agreement that
two provinces can be recognized to the south of the tropical zone; a
northern warm-temperate Peruvian Province south of about 2—6°S,
and a southern cold-temperate Magellanic Province from the south-
ern tip of the continent northwards. The boundary between these two
provinces has most often been placed at the northern end of Isla
Chiloé (about 42°S), where numerous marine invertebrates show
their distributional end points. Nevertheless, most authors have
recognized that the division is not a sharp one, and that there is a
broad area of overlap between species that are typical of each
province, so that a transitional zone can be defined, lying between 30
and 46°S (Brattstrom & Johanssen, 1983). Regional classifications
of this kind are susceptible to incomplete data and to problems of
sampling. They are also necessarily somewhat artificial, since the
geographical ranges of different taxa can be determined by various
environmental and biological factors, and influenced by their differ-
ent histories and dispersal capabilities. Nevertheless, they can provide
a useful summary of distributional data.

In this context, our study area is of interest since it lies at the
southern end of the transitional zone (46°S), and in a region of the
Chilean coastline for which distributional data for molluscs is poor.
Most previous studies of Chilean molluscs have concentrated upon
the far south, the Magellan Strait and Tierra del Fuego, and on areas
further to the north, including Isla Chiloé (see Introduction). There-
fore, it is not surprising that of the 62 species we have recorded from
the Laguna San Rafael and Estero Elefantes, 17 (27%) are extensions

D.G. REID AND C. OSORIO

to the known ranges. In the Systematic Descriptions we have
reviewed the published information on the geographical ranges of
these 62 species, and these are tabulated in Figure 8, with the
provincial boundaries of Brattstrom & Johanssen (1983) superim-
posed. Clearly, these data cannot be used in isolation to judge the
validity of biogeographic boundaries, since the sampling of species
is restricted to those occurring in one locality, and is not representa-
tive of the entire Chilean coastline. They do, however, add new
information to the previous compilation and demonstrate the
biogeographic affinities of the fauna we have studied.

In Figure 8 we have divided the species into four categories:
Antarctic (extending south of the Antarctic convergence), Magellanic
(from Cape Horn up to and including the transitional zone, 30—
56°S), widespread (occurring both south and north of the transitional
zone, including two species extending north of the equator) and
Peruvian (occurring in the Peruvian Province up to and including the
transitional zone, 146°S). The predominantly southern (Magellanic)
character of the fauna is apparent, since 30 species (48%) are strictly
Antarctic or Magellanic, and a further 26 of the widespread species
(42%) extend also to the south of our study area. Only five of the
species (8%) are strictly Peruvian. Furthermore, our records are the
northernmost for 11 species, and the southernmost for only 6
species. In their compilation of the distributions of marine inverte-
brates along the western coast of South America, Brattstrom &
Johanssen (1983) included 99 molluscan species; their list was
biased towards the better known Peruvian species, supporting their
assertion that the invertebrate fauna of Chile as a whole was pre-
dominantly northern in character and origin. These authors included
only seven Magellanic molluscs with northern limits at or to the
south of Isla Chiloé (42°S). To these our records add a further 15
species with northern limits between 42-46°S, thus emphasizing the
importance of the southern component of the Chilean fauna, and of
this region as a distributional boundary for many molluscs.

As pointed out by Brattstrom & Johanssen (1983) the biogeo-
graphical composition of the Chilean invertebrate fauna varies with
depth, the southern (Magellanic) component becoming more pro-
nounced in deeper water. Since the water is colder at depth, sublittoral
Magellanicspecies penetrate further north into the transitional zone
than strictly intertidal species. This trend is also evident in our data
(Fig. 8). Of the 26 species found only in our samples dredged from
5-15 m, 65% were Magellanic and Antarctic, 35% widespread and
none Peruvian. Of the remaining 36 species occurring in the eulittoral
zone and sublittoral fringe, 39% were Magellanic, 47% widespread
and 14% Peruvian.

Human exploitation of molluscs

Throughout much of the Chilean coastline the larger molluscs of
intertidal and shallow subtidal habitats are heavily exploited for
food by the local inhabitants (Osorio et al., 1979; Moreno et al.,
1984; Duran et al., 1987; SERNAP, 1998). Edible species found in
the present survey were Chiton granosus, Nacella magellanica,
Fissurella nigra, F- oriens, F- picta, Tegula atra, Trochita trochi-
formis, Argobuccinum pustulosum ranelliforme, Concholepas conch-
olepas, Mytilus edulis chilensis, Choromytilus chorus, Aulacomya
atra, Zygochlamys patagonica, Mulinia edulis, Ensis macha, Tagelus
dombeii, Venus antiqua and Retrotapes exalbidus. Of these, only the
bivalves and Concholepas concholepas are collected in commercial
quantities elsewhere in Chile, and only the three large mytilids are
cultivated. The exploitation of marine molluscs has a long history,
for in precolonial times the indigenous people relied heavily upon
them for food. Evidence of this was found on Isla Traiguén, where
three extensive middens were examined (stations 4, 9, 10), the

MOLLUSCA OF SOUTHERN CHILE

largest of which was about 100 m long and 5 m in depth. The age of
these middens is unknown. They correspond to the ‘white middens’
described in the detailed survey of the archaeological sites of Isla
Traiguén by Curry (in press), consisting largely of intact shells and
fragments of Aulacomya atra, Choromytilus chorus, Venus antiqua
and the large barnacle Megabalanus psittacus, together with a few
shells of Concholepas concholepas, Crepidula dilatata, Trochita
trochiformis and Mulinia edulis. Gathering of molluscs by local
fishermen in the Estero Elefantes evidently continues, since we
found collections of fresh shells of Aulacomya atra, Choromytilus
chorus, Concholepas concholepas and Venus antiqua at several sites
on the shore, although this appears to be on a small scale.

The exploitation of intertidal molluscs has implications not only
for conservation, but also for the general ecology of rocky shores. At
sites in central Chile, it has been demonstrated that where human
interference is prevented there are marked changes in zonation and
community structure. For example, Fissurella species become more
common when no longer gathered for food, grazing down the
previously abundant macroalgae such as /ridaea, and competing
with another grazer, Siphonaria lessonii (Moreno et al., 1984;
Godoy & Moreno, 1989; Duarte et al., 1996). The large mussel
Choromytilus chorus is a prized species, so heavily exploited that it
has disappeared from intertidal habitats in much of its range (Viviani,
1979), yet in a marine reserve an intertidal population soon became
established (Moreno, 1995). The most valuable, and perhaps vulner-
able, of the molluscs exploited in wild populations is Concholepas
concholepas. When intertidal collection is prevented populations on
the shore increase and include large adults that are elsewhere
restricted to the sublittoral zone; furthermore, the dense beds of
Perumytilus purpuratus and barnacles, both preyed upon by
Concholepas concholepas, become dramatically depleted (Castilla
& Duran, 1985; Moreno et al., 1986; Duran et al., 1987). Therefore,
in areas of the Chilean coast with significant human impact the
natural pattern of zonation is much altered. This emphasizes the
importance of conservation of relatively untouched coastlines such
as those of the Laguna San Rafael National Park and adjacent parts
of the Chonos Archipelago.

ACKNOWLEDGEMENTS. The biodiversity research programme in the
Laguna San Rafael National Park, of which this project was a part, was
funded by a grant from the British Government’s Darwin Initiative for the
Survival of Species. For logistic and administrative support we would like to
thank Sam Rose (Raleigh International, London), Keith Tuckwell and Graham
Hornsey (Raleigh International, Chile) and Sergio Herrera (Darwin Project,
CONAF). For their assistance and comradeship in the field we thank our
colleagues Maria Eliana Ramirez (MNHNS), Nick Evans (NHM) and David
John (NHM). This work would not have been possible without the enthusias-
tic participation of the team of Raleigh field staff and venturers who took part
in the Marine Survey of Expedition Chile 98A (January—February 1998);
staff members were Lee David, Kyle Lim, Jaime Plaza and Jill Webber;
venturers were Raimondo Benitez, Kate Bevins, Jo Brown, Nicholas
Edmeades, Stephen Fowler, Juliette Green, Joe Hoffman, Lee Joyce, Isla
McCleery, Peter Mackay-Lewis, Caroline Morgan and Clare Timmins. For
their advice on Chilean molluscs and assistance with the literature we are
most grateful to Pat Curry, Jerry Harasewych (Smithsonian Institution,
Washington, D.C.), Cristian Ituarte (Museo de La Plata, Argentina), Guido
Pastorino (Museo Argentino de Ciencias Naturales) and John Taylor (NHM).
For their comments on the manuscript we gratefully acknowledge Jim
McLean (Los Angeles County Museum of Natural History), Philippe Bouchet
(Muséum National d’ Histoire Naturelle, Paris) and David Jablonski (Univer-
sity of Chicago). Sarah Long (NHM) kindly identified the brachiopod.
Photography was by Harry Taylor (NHM). We acknowledge the support of
the Departamento de Investigacion y Desarrollo de la Universidad de Chile.

143

REFERENCES

Alvarado, J. L. & Castilla, J. C. 1996. Tridimensional matrices of mussels Perumytilus
purpuratus on intertidal platforms with varying wave forces in central Chile. Marine
Ecology Progress Series 133: 135-141.

Arnaud, P. M. 1972. Invertébrés marins des XI[éme et X Veme expéditions antarctiques
frangaises en Terre Adélie. 8. — Gastéropodes prosobranches. Téthys Supplément
4:105—134.

Benedetti—Cecchi, L. & Cinelli, F. 1997. Spatial distribution of algae and inverte-
brates in the rocky intertidal zone of the Strait of Magellan: are patterns general?
Polar Biology 18: 337-343.

Bergh, L. S. R. 1884. Report on the Nudibranchiata. Report on the Scientific Results of
the Voyage of H.M.S. Challenger During the Years 1873-76. Zoology 10: 1-151.
Bernard, F. R. 1983. Catalogue of the living Bivalvia of the Eastern Pacific Ocean:
Bering Strait to Cape Horn. Canadian Special Publication of Fisheries and Aquatic

Sciences 61: 1-102.

Beu, A. G. 1970. Taxonomic position of Lippistes pehuensis Marwick, with a review
of the species of Concholepas (Gastropoda, Muricidae). Journal of the Malacological
Society of Australia 2: 39-46.

1985a. A classification and catalogue of living world Ranellidae (=Cymatiidae)

and Bursidae. Conchologists of America Bulletin 13: 55-66.

1985b. Pleistocene Chlamys patagonica delicatula (Bivalvia: Pectinidae) off
southeastern Tasmania, and history of its species group in the Southern Ocean.
Special Publication, South Australian Department of Mines and Energy 5: \-11.

Blainville, H. M. D. de 1827. Siphonaire. Planches deuxiéme partie: Régne Organisé,
Zoologie. pp. 291-296. In: Levrault, F. G. (ed.) Dictionnaire des Sciences Naturelles
49. Strasbourg & Paris.

Born, I. von 1778. Index Rerum Naturalium Musei Caesarei Vindobonensis. Pars
Prima, Testacea. Vienna.

Bouchet, P. & Warén, A. 1993. Revision of the northeast Atlantic bathyal and abyssal
Mesogastropoda. Bollettino Malacologico, Supplemento 3: 579-840.

Brace, R. C. 1983. Observations on the morphology and behaviour of Chilina fluctuosa
Gray (Chilinidae), with a discussion on the early evolution of pulmonate gastropods.
Philosophical Transactions of the Royal Society of London, Series B 300: 463-491.

Brattstrom, H. 1990. Intertidal ecology of the northernmost part of the Chilean
archipelago. Report 50 of the Lund University Chile Expedition 1948-49. Sarsia 75:

107-160.

Brattstrom, B. & Johanssen, A. 1983. Ecological and regional zoogeography of the
marine benthic fauna of Chile. Report no. 49 of the Lund University Chile Expedi-
tion 1948-49. Sarsia 68: 289-339.

Bretos, M., Gutiérrez, J. & Espinoza, Z. 1988. Estudios biol6gicos para el manejo de
Fissurella picta. Medio Ambiente 9: 28-34.

Bretos, M., Quintana, V. & Ibarrola, V. 1988. Bases bioldgicas para el manejo de
Fissurella nigra. Medio Ambiente 9: 55-62.

Broderip, W. J. & Sowerby, G. B. 1832. Characters of new species of Mollusca and
Conchifera, collected by Mr Cuming. Proceedings of the Zoological Society of
London 1832: 104-108.

— 1833. [Collection of shells formed by Mr. Cuming on the western coast of South
America, and among the islands of the southern Pacific Ocean]. Proceedings of the
Zoological Society of London 1832: 194-202.

Bruguieére, J. 1789. Encyclopédie Méthodique. Histoire Naturelle des Vers. 1.

Bullock, R. C. 1988. The genus Chiton in the New World (Polyplacophora: Chitonidae).
Veliger 31: 141-191.

Canete, J. I. & Ambler, R. P. 1992. Desarrollo intracapsular del gastropodo comestible
Calyptraea (Trochita) trochiformis (Born, 1778), en Chile. Revista Chilena de
Historia Natural 65: 255-266.

Carcelles, A. R. 1944. Catalogo de los moluscos marinos de Puerto Quequén. Revista
del Museo de La Plata. Nueva Serie, Zoologia 3: 233-309.

1950. Catalogo de los moluscos marinos de la Patagonia. Anales del Museo

Nahuel Huapi 2: 41-100.

1954. Especies sudamericanas de Argobuccinum Bruguiére 1792. Comunicaciones
del Instituto Nacional de Investigacion de las Ciencias Naturales 2: 243-254.

Carcelles, A. R. & Williamson, S. I. 1951. Catalogo de los moluscos marinos de la
Provincia Magellanica. Revista del Instituto Nacional de Investigacion de las
Ciencias Naturales 2: 225-383.

Castellanos, Z. A. de 1979. Micromoluscos poco conocidos del sur Argentino-
Chileno. Neotropica 25: 133-140.

1990. Catalogo Descriptivo de la Malacofauna Marina Magellanica 5. Comision

de Investigaciones Cientificas, Buenos Aires.

1992. Catalogo Descriptivo de la Malacofauna Marina Magellanica 7 & 8.
Comisién de Investigaciones Cientificas, Buenos Aires.

Castellanos, Z. A. de & Gaillard, M. C. 1981. Mollusca Gasteropoda Chilinidae.
Fauna de Agua Dulce de la Republica Argentina 15: 19-51.

Castellanos, Z. A. de & Landoni, N. 1988. Catalogo Descriptivo de la Malacofauna
Marina Magellanica 2. Comision de Investigaciones Cientificas, Buenos Aires.
1989. Catalogo Descriptivo de la Malacofauna Marina Magellanica 3. Comision

de Investigaciones Cientificas, Buenos Aires.

144

—1992. Catalogo Descriptivo de la Malacofauna Marina Magellanica 10. Comisi6n
de Investigaciones Cientificas, Buenos Aires.

1993. Catalogo Descriptivo de la Malacofauna Marina Magellanica 9.
Neogastropoda. Comisién de Investigaciones Cientificas, Buenos Aires.

Castilla, J. C. 1982. Pesqueria de moluscos gastropodos en Chile: Concholepas
concholepas, un caso de estudio. Monografias Biologicas 2: 199-212.

1985. Food webs and functional aspects of the kelp, Macrocystis pyrifera, com-
munity in the Beagle Channel, Chile. pp. 407-414. In: Siegfried, W. R., Condy, P. R. &
Laws, R. M. (eds) Antarctic Nutrient Cycles and Food Webs. Springer-Verlag, Berlin.

Castilla, J. C. & Cancino, J. 1976. Spawning behaviour and egg capsules of
Concholepas concholepas (Mollusca: Gastropoda: Muricidae). Marine Biology 37:
255-263.

Castilla, J. C. & Duran, L. R. 1985. Human exclusion from the rocky intertidal zone
of central Chile: the effects on Concholepas concholepas (Gastropoda). Oikos 45:
391-399.

Castilla, J. C., Guisado, C. & Cancino, J. 1979. Aspectos ecolégicos y conductuales
relacionados con la alimentacion de Concholepas concholepas (Mollusca: Gastro-
poda: Muricidae). Biologia Pesquera 12: 99-114.

Cazzaniga, N. J. 1994. A concern for grammar: the name of the Magellanic mussel
(Bivalvia: Mytilidae). Malacological Review 27: 110.

Cernohorsky, W. O. 1975. The taxonomy of some West American and Atlantic
Nassariidae based on their type-specimens. Records of the Auckland Institute and
Museum 12: 121-173.

1977. The taxonomy of some Southern Ocean Mollusca (Gastropoda) mainly

Antarctic and Subantarctic. Records of the Auckland Institute and Museum 14: 105—

119.

1984. Systematics of the family Nassartidae (Mollusca: Gastropoda). Bulletin of
the Auckland Institute and Museum 14: 1-356.

Chavan, A. 1969. Superfamily Carditacea Fleming, 1820. pp. 543-561. In: Moore, R.
C. (ed.) Treatise on Invertebrate Paleontology. Part N. Mollusca 6. Geological
Society of America, Lawrence, Kansas.

Clasing, E., Brey, T., Stead, R., Navarro, J. & Asencio, G. 1994. Population
dynamics of Venus antiqua (Bivalvia: Veneracea) in the Bahia de Yaldad, Isla de
Chiloé, southern Chile. Journal of Experimental Marine Biology and Ecology 177:
171-186.

Clench, W. J. & Turner, R. D. 1964. The subfamilies Volutinae, Zidoninae, Odonto-
cymbiolinae and Calliotectinae in the western Atlantic. Johnsonia 4: 129-180.

Cosel, R. von 1990. An introduction to the razor shells (Bivalvia: Solenacea). pp. 283—
311. In: Morton, B. (ed.) The Bivalvia — Proceedings of a Memorial Symposium in
Honour of Sir Charles Maurice Yonge, Edinburgh, 1986. Hong Kong University
Press, Hong Kong.

Curry, P. J. In press. Archaeology. In: Aldridge, D. (ed.) Laguna San Rafael National
Park, Chile. The Natural History of a Patagonian Wilderness.

Dall, W. H. 1909. Report on a collection of shells from Peru, with a summary of the
littoral marine Mollusca of the Peruvian zoological province. Proceedings of the
United States National Museum 37: 147-294.

Davenport, J. & others 1995. The marine ecology of the Laguna San Rafael (southern
Chile): ice scour and opportunism. Estuarine, Coastal and Shelf Science 41: 21-37.

Deambrosi, D. F. de 1969. La radula como caracter diagnostico en los generos
Margarella y Margarita y nueva ubicacion de algunas especies — (Mollusca). Acta
Zoologica Lilloana 24: 50-55.

Dell, R. K. 1964. Antarctic and subantarctic Mollusca: Amphineura, Scaphopoda and
Bivalvia. Discovery Reports 33: 93-250.

1971. The marine Mollusca of the Royal Society Expedition to Southern Chile,

1958-1959. Records of the Dominion Museum 7: 155-233.

1972. Notes on nomenclature of some Mollusca from Antarctica and southern

South America. Records of the Dominion Museum 8: 21-42.

1990. Antarctic Mollusca with special reference to the fauna of the Ross Sea.
Bulletin of the Royal Society of New Zealand 27: 1-311.

DeVries, T. J. 1995. Concholepas Lamarck, 1801 (Neogastropoda: Muricoidea): a
Neogene genus native to South America. Veliger 38: 284-297.

Dillwyn, L. W. 1817. A Descriptive Catalogue of Recent Shells 2. J. & A. Arch,
London.

DiSalvo, L. H. 1988. Observations on the larval and post-metamorphic life of
Concholepas concholepas (Bruguiére, 1789) in laboratory culture. Veliger 30: 358—
368.

Duarte, W. E., Asencio, G. & Moreno, C. A. 1996. Long-term changes in population
density of Fissurella picta and Fissurella limbata (Gastropoda) in the marine reserve
of Mehuin, Chile. Revista Chilena de Historia Natural 69: 45-56.

Duran, L. R., Castilla, J. C. & Oliva, D. 1987. Intensity of human predation on rocky
shores at las Cruces in central Chile. Environmental Conservation 14: 143-149.
Eliot, C. N. E. 1907. Nudibranchs from New Zealand and the Falkland Islands.

Proceedings of the Malacological Society of London 7: 327-361.

Espoz, C., Guzman, G. & Castilla, J. C. 1995. The lichen Thelidium litorale on shells
of intertidal limpets: a case of lichen-mediated cryptic mimicry. Marine Ecology
Progress Series 119: 191-197.

Ferreira, A. J. 1982. Taxonomic notes on Chiton carmichaelis Gray, 1828, type
species of Plaxiphora Gray, 1847. Veliger 25: 43-50.

D.G. REID AND C. OSORIO

1983. 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: 203-224.

Fischer-Piette, E. & Vukadinovic, D. 1977. Suite des révisions des Veneridae (Moll.
Lamellibr.) Chioninae, Samaranginae et complément aux Venus. Mémoires du Muséum
National d’Histoire Naturelle. Nouvelle Serie. Série A, Zoologie 106: 1-186.

Fischer-Piette, F. 1975. Révision des Venerinae s.s. (Mollusques Lamellibranches).
Mémoires du Muséum National d’Histoire Naturelle. Nouvelle Serie. Série A,
Zoologie 93: |-64.

Frembly, J. 1827. A description of several new species of chitones, found on the coast
of Chili, in 1825; with a few remarks on the method of taking and preserving them.
Zoological Journal 3: 193-205.

Gallardo, C. & Osorio, C. 1978. Hiatella solida (Sowerby, 1834) (Mollusca: Hiatel-
lidae) on Concholepas concholepas (Bruguiére, 1789) and other substrates. Veliger
20: 274-278.

Gallardo, C. S. 1977. Two modes of development in the morphospecies Crepidula dilat-
ata (Gastropoda: Calyptraeidae) from southern Chile. Marine Biology 39: 241-251.

1979. Especies gemelas del genero Crepidula (Gastropoda, Calyptraeidae) en la
costa de Chile; una redescription de C. dilatata Lamarck y description de C. fecunda
n. sp. Studies on Neotropical Fauna and Environment 14: 215-226.

Gmelin, J. F. 1791. Caroli a Linné . . . Systema Naturae per Regna Tria Naturae. 1,
part 6. Edition 13. Lugduni.

Godoy, C. & Moreno, C. A. 1989. Indirect effects of human exclusion from rocky inter-
tidal in southern Chile: a case of cross-linkage between herbivores. Oikos 54: 101-106.

Gonzalez, M. & Jaramillo, E. 1991. The association between Mulinia edulis (Mol-
lusca, Bivalvia) and Edotea magellanica (Crustacea, Isopoda) in southern Chile.
Revista Chilena de Historia Natural 64: 37-51.

Gordillo, S. 1995. Subfossil and living Hiatella solida (Sowerby) from the Beagle
Channel, South America. Quaternary of South America and Antarctic Peninsula 9:
183-204.

Gosling, E. 1992. Systematics and geographical distribution of Myrilus. pp. 1-20. In:
Gosling, E. (ed.) The Mussel Mytilus: Ecology, Physiology, Genetics and Culture.
Elsevier, Amsterdam.

Gray, J-E. 1839. Molluscous animals. pp. 101-155. In: Beechey, F.W. (ed.) The
Zoology of Captain Beechey’s Voyage. H.G. Bohn, London.

Gruber, G. L. & Carriker, M. R. 1990. A note on the accessory boring organ and shell
boring by the ‘loco’, Concholepas concholepas (Muricidae, Gastropoda). Bulletin of
Marine Science 47: 739-744.

Guiler, E. R. 1959a. Intertidal belt-forming species on the rocky coasts of northern
Chile. Papers and Proceedings of the Royal Society of Tasmania 93: 33-58.

1959b. The intertidal ecology of the Montemar area, Chile. Papers and Proceed-
ings of the Royal Society of Tasmania 93: 165-183.

Guzman, M. L. 1978. Patron de distribucién espacial y densidad de Nacella magellanica
(Gmelin, 1791) en el intermareal del sector oriental del estrecho de Magallanes
(Mollusca, Gastropoda). Anales del Instituto de la Patagonia 9; 205-219.

Haeckel, W. 1911. Beitrage zur Anatomie der Gattung Chilina. Zoologische Jahrbiicher.
Supplement 13: 89-136.

Helbling, G. S. 1779. Beytrage zur Kenntnis neuer und seltener Konchylien.
Abhandlungen einer Privatgesellschaft in B6hmen 4: 102-131.

Herbert, D. G. & Kilburn, R. N. 1986. Taxonomic studies on the Emarginulinae
(Mollusca: Gastropoda: Fissurellidae) of southern Africa and Mozambique.
Emarginula, Emarginella, Puncturella, Fissurisepta and Rimula. South African
Journal of Zoology 21: 1-27.

Herm, D. 1969. Marines Pliozaén und Pleistozaén in Nord- und Mittel-Chile unter
besonderer Beriicksichtigung der Entwicklung der Mollusken-Faunen. Zitteliana 2:
1-159.

Hickman, C. S. & McLean, J. H. 1990. Systematic Revision and Suprageneric
Classification of Trochacean Gastropods. 169 p. Natural History Museum of Los
Angeles County, Los Angeles.

Hoagland, K. E. 1977. Systematic review of fossil and Recent Crepidula and discus-
sion of evolution of the Calyptraeidae. Malacologia 16: 353-420.

Hockey, P. A., Bosman, A. L. & Ryan, P. G. 1987. The maintenance of polymorphism
and cryptic mimesis in the limpet Scurria variabilis by two species of Cinclodes
(Aves: Furnartinae) in central Chile. Veliger 30: 5-10.

Houbrick, R. S. 1987. Description of a new, giant Ataxocerithium species from
Australia with remarks on the systematic placement of the genus (Prosobranchia:
Cerithiopsidae). Nautilus 101: 155-161.

Hubendick, B. 1946. Systematic monograph of the Patelliformia. Kungliga Svenska
Vetenskapsakademiens Handlingar. Ser. 3 23(5): 1-93.

Hupé, H. 1854. Fauna Chilena. Moluscos. pp. 1-476. In: Gay, C. (ed.) Historia Fisica
y Politica de Chile. Zoologia 8. Paris.

Ituarte, C. F. 1997. Chilina megastoma Hylton Scott, 1958 (Pulmonata: Basommat-
ophora): a study on topotypic specimens. American Malacological Bulletin 14: 9-15.

Jara, H. F. & Moreno, C. A. 1984. Herbivory and structure in a midlittoral rocky
community: a case in southern Chile. Ecology 65: 28-38.

Jaramillo, E., Mulson, S. & Navarro, R. 1985. Intertidal and subtidal macroinfauna
in the Queule River Estuary, south of Chile. Revista Chilena de Historia Natural 58:
127-137.

MOLLUSCA OF SOUTHERN CHILE

Jordan, J. & Ramorino, L. 1975. Reproduccion de Littorina (Austrolittorina) peruvi-
ana (Lamarck, 1822) y Littorina (Austrolittorina) araucana d’Orbigny, 1840.
Revista de Biologia Marina 15: 227-261.

Kaas, P. & Van Belle, R. A. 1985. Monograph of Living Chitons (Mollusca:
Polyplacophora). Volume 1. Order Neoloricata: Lepidopleurina. E. J. Brill & W.
Backhuys, Leiden.

1987. Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 3.

Suborder Ischnochitonina. Ischnochitonidae: Chaetopleurinae, & Ischnochitoninae

(pars). Additions to Vols 1 & 2. E. J. Brill & W. Backhuys, Leiden.

1990. Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 4.

Suborder Ischnochitonina: Ischnochitonidae: Ischnochitoninae (continued). Addi-

tions to Vols 1, 2 and 3. E. J. Brill, Leiden.

1994. Monograph of Living Chitons (Mollusca: Polyplacophora). Volume 5.

Suborder Ischnochitonina: Ischnochitonidae (concluded), Callistoplacinae;

Mopaliidae. Additions to Vols 1-4. E. J. Brill, Leiden.

1998. Catalogue of Living Chitons (Mollusca, Polyplacophora). Backhuys Pub-
lishers, Leiden.

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

Kiener, L.-C. 1834. Genre Buccin. pp. 1-112. In: Kiener, L.-C. (ed.) Spécies Général
et Iconographie des Coquilles Vivantes, Part 10. Rousseau and Bailliére, Paris.
Kilburn, R. N. & Rippey, E. 1982. Sea Shells of Southern Africa. 249 p. Macmillan

South Africa, Johannesburg.

King, P. P. & Broderip, W. J. 1832. Description of the Cirrhipeda, Conchifera and
Mollusca, in a collection formed by the officers of H.M.S. Adventure and Beagle
employed between the years 1826 and 1830 in surveying the southern coasts of South
America, including the Straits of Magalhaens and the coast of Tierra del Fuego.
Zoological Journal 5: 332-349.

Kool, S. P. 1993. Phylogenetic analysis of the Rapaninae (Neogastropoda: Muricidae).
Malacologia 35: 155-259.

Lamarck, J. B. P. A. de M. de 1818, 1819, 1822. Histoire Naturelle des Animaux Sans
Vertébres. 5, 6. Paris.

Lamy, E. 1922. Révision des Carditacea vivants du Muséum National d’ Histoire
Naturelle de Paris (suite). Journal de Conchyliologie 66: 289-368.

Leloup, E. 1956. Reports of the Lund University Chile Expedition 1948-49. 27.
Polyplacophora. Lunds Universitets Arsskrift, N. F. Avd. 2 52(15): 1-94.

Lesson, R. P. 1831. Mollusques. pp. 239-448. In: Duperrey, M. L. I. (ed.) Voyage
Autour du Monde, Exécuté par Ordre du Roi, sur la Corvette de Sa Majesté, La
Coquille, pendant les Anneés 1822, 1823, 1824 et 1825. Zoologie , 2(1). Paris.

Lewis, J. R. 1964. The Ecology of Rocky Shores. English University Press, London.

Lightfoot, J. 1786. A Catalogue of the Portland Museum. London.

Lindberg, D. R. 1988. The Patellogastropoda. Malacological Review. Supplement 4:
35-63.

Linnaeus, C. 1758. Systema Naturae per Regna Tria Naturae, Secundum Classes,
Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis 1.
Edition 10. Laurentii Salvii, Holmiae.

Linse, K. 1997. Die Verbreitung epibenthischer Mollusken im chilenischen Beagle-
Kanal. Berichte zur Polarforschung 228: 1-131.

Linse, K. & Brandt, A. 1998. Distribution of epibenthic Mollusca on a transect
through the Beagle Channel (southern Chile). Journal of the Marine Biological
Association of the United Kingdom 78: 875-889.

Lopez-Gappa, J. & Tablado, A. 1997. Growth and production of an intertidal
population of the chiton Plaxiphora aurata (Spalowski, 1795). Veliger 40: 263-270.

Lozada, E. 1968. Contribucion al estudio de la cholga Aulacomya ater en Putemtn.
Biologia Pesquera 3: 3-39.

Lozada, E., Rolleri, J. & Yanez, R. 1971. Consideraciones biol6gicas de Choromytilus
chorus en dos sustratos diferentes. Biologia Pesquera 5: 61-108.

Mabille, J. & Rochebrune, A. T. 1889. Mollusques. In: Mission Scientifique du Cap
Horn, 1882-3. 6, Zoology 2. Paris.

Malusa, J. A. 1985. Attack mode in a predatory gastropod: labial spine length and the
method of prey capture in Acanthina angelica Oldroyd. Veliger 28: 1-5.

Marcus, E. 1959. Reports of the Lund University Chile Expedition 1948-49. 36. Lamel-
lariacea und Opisthobranchia. Lunds Universitets Arsskrift, N. F. Avd. 2 55(9): 1-133.

Maxwell, P. A. 1988. Comments on ‘A reclassification of the Recent genera of the
subclass Protobranchia (Mollusca: Bivalvia)’ by J. A. Allen and F. J. Hannah (1986).
Journal of Conchology 33: 85-96.

McDonald, J. H., Seed, R. & Koehn, R. K. 1991. Allozymes and morphometric
characters of three species of Mytilus in the Northern and Southern Hemispheres.
Marine Biology 111: 323-333.

McLean, J. H. 1984. Systematics of Fissurella in the Peruvian and Magellanic faunal
provinces (Gastropoda: Prosobranchia). Contributions in Science, Natural History
Museum of Los Angeles County 354: 1-70.

Melvill, J. C. & Standen, R. 1912. The marine Mollusca of the Scottish National
Antarctic Expedition. Part Il. Transactions of the Royal Society of Edinburgh 48:
333-366.

Miranda, O. & Acuna, E. 1979. Mytilus edulis chilensis (Hupé, 1854) en Cabo Negro
(Provincia de Magellanes) (Mollusca, Bivalvia, Mytilidae). Revista de Biologia
Marina 16: 331-353.

145

Molina, G. I. 1782. Saggio sulla Storia Naturale del Chili. T. d’ Aquino, Bologna.

Moreno, C. A. 1995. Macroalgae as a refuge from predation for recruits of the mussel
Choromytilus chorus (Molina, 1782) in southern Chile. Journal of Experimental
Marine Biology and Ecology 191: 181-193.

Moreno, C. A. & Jaramillo, E. 1983. The role of grazers in the zonation of intertidal
macroalgae of the Chilean coast. Oikos 41: 73-76.

Moreno, C. A., Lunecke, K. M. & Lepez, M. I. 1986. The response of an intertidal
Concholepas concholepas (Gastropoda) population to protection from man in
southern Chile and the effects on benthic sessile assemblages. Oikos 46: 359-364.

Moreno, C. A., Reyes, A. & Asencio, G. 1993. Habitat and movements of the recruits
of Concholepas concholepas (Mollusca; Muricidae) in the rocky intertidal of
southern Chile. Journal of Experimental Marine Biology and Ecology 171: 51-61.

Moreno, C. A., Sutherland, J. P. & Jara, H. F. 1984. Manas a predator in the intertidal
zone of southern Chile. Oikos 42: 155-160.

Morrison, J. P. E. 1963. Notes on American Siphonaria. American Malacological
Union Annual Reports 1963: 7-9.

Moskaley, L. I. 1977. A revision of the Lepetidae (Gastropoda, Prosobranchia) of the
worldocean. Trudy Instituta Okeanologii im. P. P. Shirshova 108: 52-78. (In Russian).

Navarro, J. M. 1988. The effects of salinity on the physiological ecology of
Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae). Journal of Experimental
Marine Biology and Ecology 122: 19-33.

(0) Foighil, D. & Smith, M. J. 1995. Evolution of asexuality in the cosmopolitan marine
clam Lasaea. Evolution 49: 140-150.

Ojeda, F. P. & Santelices, B. 1984. Invertebrate communities in holdfasts of the kelp
Macrocystis pyrifera from southern Chile. Marine Ecology — Progress Series 16:
65-73.

Oliva, D. & Castilla, J. C. 1992. Guia para el reconocimiento y morphometria de diez
especies del género Fissurella Bruguiere, 1789 (Mollusca: Gastropoda) comunes en
la pesqueria y conchales indigenas de Chile Central y Sur. Guyana, Zoologia 56: 77—
108.

Olivier, S. R. & Penchaszadeh, P. E. 1968. Observaciones sobre la ecologia y biologia
de Siphonaria (Pachysiphonaria) lessoni (Blainville, 1824) (Gastropoda,
Siphonariidae) en la litoral rocoso de Mar del Plata (Buenos Aires). Cahiers de
Biologie Marine 9: 469-491.

Olsson, A. A. 1961. Mollusks of the Tropical Eastern Pacific. Panamic-Pacific
Pelecypoda. Paleontological Research Institution, Ithaca, New York.

Orbigny, A. d’ 1834-1847. Voyage dans l’Amérique Méridionale 5 (3): Mollusques. P.
Bertrand, Paris.

Osorio, C., Atria, J. & Mann, S. 1979. Moluscos marinos de importancia econédmica
en Chile. Biologia Pesquera 11: 3-47.

Osorio, C. & Bahamonde, N. 1970. Lista preliminar de Lamelibranquios de Chile.
Boletin del Museo Nacional de Historia Natural 31: 185-256.

Osorio, C., Frassinetti, D. & Bustos, E. 1983. Taxonomia y morfometria de Venus
antiqua antiqua King y Broderip, 1835 (Mollusca, Bivalvia, Veneridae). Téthys 11:
49-56.

Otaiza, R. D. & Santelices, B. 1985. Vertical distribution of chitons (Mollusca:
Polyplacophora) in the rocky intertidal zone of central Chile. Journal of Experimen-
tal Marine Biology and Ecology 86: 229-240.

Pallas, P. S. 1774. Spicilegia Zoologica Quibus Novae Imprimis et Obscurae
Animalium Species. Part 10. Berolini, Lange.

Palmer, A. R. 1990. Effect of crab effluent and scent of damaged conspecifics on
feeding, growth, and shell morphology of the Atlantic dogwhelk Nucella lapillus
(L.). Hydrobiologia 193: 155-182.

Pastorino, G. & Harasewych, M.G. 2000. A revision of the Patagonian genus
Xymenopsis Powell, 1951 (Gastropoda: Muricidae). Nautilus 114: 38-58.

Paterson, G. L. J., John, D. M., Spencer-Jones, M., Ramirez, M. E., Evans, N. J.,
Davenport, J., Manly, R., Reid, D. G., Osorio, C., Clark, P. F., Plaza, J., Rose, S.
& Letelier, S. In press. Marine biology of the Laguna San Rafael National Park. In:
Aldridge, D. (ed.) Laguna San Rafael National Park, Chile. The Natural History of
a Patagonian Wilderness.

Perry, D. M. 1985. Function of the shell spine in the predaceous rocky intertidal snail
Acanthina spirata (Prosobranchia: Muricacea). Marine Biology 88: 51-58.

Philippi, R. A. 1845. Diagnosen einiger neuen Conchylien. Archiv fiir Naturgeschichte
11: 50-71.

1845-1847. Abbildungen und Beschreibungen neuer oder wenig gekannter
Conchylien 2. Theodor Fischer, Cassel.

Pickard, G. L. 1971. Some physical oceanographic features of inlets of Chile. Journal
of the Fisheries Research Board of Canada 28: 1077-1106.

Plate, L. H. 1899. Die Anatomie und Phylogenie der Chitonen. Fortsetzung. Zoologische
Jahrbiicher Supplement-band 5: 15-216.

Ponder, W. F. & Worsfold, T. M. 1994. A review of the rissoiform gastropods of south-
western South America (Mollusca, Gastropoda). Contributions in Science 445: 1-63.

Poppe, G. T. & Goto, Y. 1992. Volutes. Mostra Mondiale Malacologia, Cupra
Marittima, Italy.

Powell, A. W. B. 1951. Antarctic and subantarctic Mollusca: Pelecypoda and Gastro-
poda. Discovery Reports 26: 47-196.

1960. Antarctic and subantarctic Mollusca. Records of the Auckland Institute and

Museum 5: 117-193.

146

— 1973. The patellid limpets of the world. Indo-Pacific Mollusca 3: 75-205.

1979. New Zealand Mollusca. 500 p. Collins, Auckland.

Rabi, M., Yamashiro, C. & Quiroz, M. 1996. Revision de la biologia y pesqueria del
recurso chanque Concholepas concholepas (Bruguiére, 1789) (Mollusca: Gastro-
poda: Muricidae). Informe Progresivo. Instituto del Mar del Peri 31: 3-23.

Ramirez, J. 1974. Nuevas especies chilenas de Lucapina, Fissurella y Collisella
(Mollusca, Archaeogastropoda). Boletin del Museo Nacional de Historia Natural
33: 15-34.

Ramorino, L. 1968. Pelecypoda del fondo de la Bahia de Valparaiso. Revista de
Biologia Marina 13: 175-285.

Reeve, L. A. 1843. Monograph of the genus Cardita. Pls 1-9. In: Reeve, L. A. (ed.)
Conchologia Iconica. L. A. Reeve, London.

—— 1844. Description of new species of shells figured in the ‘Conchologia Iconica’.
Proceedings of the Zoological Society of London 1843: 168-197.

1854. Monograph of the genus Patella. Pls 1-16 (1857), 17-18 (1858). In: Reeve,
L. A. (ed.) Conchologia Iconica. L. A. Reeve, London.

Rehder, H. A. 1943. The molluscan genus Trochita Schumacher with a note on
Bicatillus Swainson. Proceedings of the Biological Society of Washington 56: 41—
46.

Reid, D. G. 1989. The comparative morphology, phylogeny and evolution of the
gastropod family Littorinidae. Philosophical Transactions of the Royal Society of
London. Series B 324: 1-110.

— 1996. Systematics and Evolution of Littorina. 463 p. Ray Society, London.

Reid, H. P. 1974. La trayectoria del ducto digestivo de Mytilus chilensis Hupé, 1854 y
su valor sistematico. Boletin de la Sociedad de Biologia de Concepcion 48: 179-184.

Rio, C. J. del 1997. Cenozoic biogeographic history of the eurythermal genus Retro-
tapes, new genus (subfamily Tapetinae) from southern South America and Antarctica.
Nautilus 110: 77-93.

Romo, H. & Alveal, K. 1977. Los comunidades de litoral rocoso de Punta Ventanilla
Bahia de Quintero — Chile. Gayana Miscelanea 6: \-41.

Ruiz, E. & Giampaoli, L. 1981. Estudios distribucionales de la flora y fauna costera de
Caleta Cocholgue, Bahia de Concepcion — Chile. Boletin de la Sociedad de Biologia
de Concepcion 52: 145-166.

Santelices, B. 1991. Littoral and sublittoral communities of continental Chile. pp. 347—
369. In: Mathieson, A. C. & Nienhuis, P. H. (eds) Intertidal and Littoral Ecosystems.
Ecosystems of the World 24. Elsevier, Amsterdam.

Sasaki, T. 1998. Comparative anatomy and phylogeny of the Recent Archaeogastropoda
(Mollusca: Gastropoda). Bulletin. University Museum, University of Tokyo 38: \—
224.

Schrodl, M. 1996. Nudibranchia y Sacoglossa de Chile: morpholgia externa y
distribucion. Gayana Zoologia 60: 17-62.

— 1997. Range extensions of Magellanic nudibranchs (Opisthobranchia) into the
Peruvian faunal province. Veliger 40: 38-42.

Seed, R. 1992. Systematics evolution and distribution of mussels belonging to the
genus Mytilus: an overview. American Malacological Bulletin 9: 123-137.

Servicio Nacional de Pesca. 1998. Anuario Estadistico de Pesca 1997. Departamento
de Sistemas de Informacién y Estadistica, Santiago.

Smith, E. A. 1875. Description of a new species of Solenella from south Patagonia.
Annals and Magazine of Natural History. Series 4 16: 118-119.

— 1881. Account of the zoological collections made during the survey of H. M. S.
‘Alert’ in the Straits of Magellan and on the coast of Patagonia. IV. Mollusca and
Molluscoida. Proceedings of the Zoological Society of London 1881: 22-44.

Smith, J. T. 1970. Taxonomy, distribution, and phylogeny of the cymatiid gastropods
Argobuccinum, Fusitriton, Mediargo, and Priene. Bulletins of American Paleontology
56: 445-574.

Soot-Ryen, T. 1955. A report on the family Mytilidae (Pelecypoda). Allan Hancock
Pacific Expeditions 20: 1-174.

— 1959. Reports of the Lund University Chile Expedition 1948-49. 35. Pelecypoda.
Lunds Universitets Arsskrift. N. F. Avd. 2 55(6): 1-86.

Sowerby, G. B. 1833a. A catalogue of recent species of Nuculae. pp. 3-6. In: Sowerby,
G. B. (ed.) The Conchological Illustrations Part 14. Sowerby, London.

— 1833b. New species of shells collected by Mr. Cuming on the western coast of
South America, and among the islands of the South Pacific Ocean. Proceedings of
the Zoological Society of London 1833: 34-38.

—— 1834. New species of shells contained in the collection formed by Mr. Cuming on
the western coast of South America, and among the islands of the South Pacific
Ocean. Proceedings of the Zoological Society of London 1834: 87-89.

— 1835. Shells collected by Mr. Cuming on the western coast of South America, and
among the islands of the South Pacific Ocean . . . undescribed species of the genus
Fissurella. Proceedings of the Zoological Society of London 1834: 123-128.

—— 1838. A descriptive catalogue of the species of Leach’s genus Margarita.
Malacological and Conchological Magazine 1: 23-27.

1840. Description of some new chitons. Magazine of Natural History (new series)

4: 287-294.

1874. Monograph of the genus Chilina. In: Reeve, L. A. (ed.) Conchologia
Iconica, L. A. Reeve, London.

Spalowsky, J. J. N. A. 1795. Prodromus in Systema Historicum Testaceorum. Wien.

D.G. REID AND C. OSORIO

Stempell, W. 1899. Die Muscheln der Sammlung Plate. Zoologische Jahrbiicher.
Supplementband 5: 217-250.

Stotz, W. B. 1981. Aspectos ecoldgicos de Mytilus edulis chilensis (Hupé, 1854) en el
estuario del rio Lingue (Valdivia, Chile). Revista de Biologia Marina 17: 335-377.

Strebel, H. 1904. Beitrage zur Kenntnis der Molluskenfauna der Magalhaen-Provinz.
I. Zoologische Jahrbiicher. Abteilung fiir Systematik, Geographie und Biologie der
Tiere 21: 171-248.

1905a. Beitraége zur Kenntnis der Molluskenfauna der Magalhaen-Provinz. II. Die
Trochiden. Zoologische Jahrbiicher. Supplement 8: 121-166.

— 1905b. Beitrage zur Kenntnis der Molluskenfauna der Magalhaen-Provinz. No. 3.
Zoologische Jahrbiicher. Abteilung fiir Systematik, Geographie und Biologie der
Tiere 22: 575-666.

1906. Beitrage zur Kenntnis der Molluskenfauna der Magalhaen-Provinz. No. 4.
Zoologische Jahrbiicher. Abteilung fiir Systematik, Geographie und Biologie der
Tiere 24: 91-174.

—— 1907. Beitrage zur Kenntnis der Molluskenfauna der Magalhaen-Provinz. No. 5.
Zoologische Jahrbiicher. Abteilung fiir Systematik, Geographie und Biologie der
Tiere 25: 79-196.

Stuardo, J. 1961. Contribucion a un catélogo de los moluscos gaster6podos Chilenos
de agua dulce. Gayana. Zoologia 1: 1-32.

— 1964. Distribucion de los moluscos marinos litorales en latinoamerica. Boletin del
Instituto de Biologia Marina. Mar del Plata 7: 79-91.

— 1979. Sobre la clasificacion, distribucion y variacion de Concholepas concholepas
(Bruguiére, 1789): un estudio de taxonomia beta. Biologia Pesquera 12: 5-38.

Suchanek, T. H. 1985. Mussels and their rdle in structuring rocky shore communities.
pp. 70-96. In: Moore, P. G. & Seed, R. (eds) The Ecology of Rocky Coasts. Hodder
& Stoughton, London.

Taylor, J. D. & Smythe, K. R. 1985. A new species of Trochita (Gastropoda:
Calyptraeidae) from Oman: a relict distribution and association with upwelling
areas. Journal of Conchology 32: 39-48.

Thompson, T. E. & Brown, G. H. 1984. Biology of Opisthobranch Molluscs 2. 229 p.
Ray Society, London.

Thore, S. 1959. Reports of the Lund University Chile Expedition 1948-49. 33.
Cephalopoda. Lunds Universitets Arsskrift N. F. Avd. 2 55 (1): 1-19.

Turner, R. D. 1966. A Survey and Illustrated Catalogue of the Teredinidae (Mollusca:
Bivalvia). 265 p. Museum of Comparative Zoology, Harvard University, Cambridge,
Mass.

Ubaldi, R. 1985. A contribution to the knowledge of genus Nacella Schumacher, 1817
in the Antarctic and Sub-Antarctic regions. (Part 1). Argonauta 1: 10-22.

Urban, H.-J. 1994. Adaptations of six infaunal bivalve species of Chile: coexistence
resulting from differences in morphology, burrowing depth and substrate preference.
Archive of Fishery and Marine Research 42: 183-193.

—— 1996. Population dynamics of the bivalves Venus antiqua, Tagelus dombeii, and
Ensis macha from Chile at 36°S. Journal of Shellfish Research 15: 719-727.

Urban, H.-J. & Tesch, C. 1996. Aspects of the population dynamics of six bivalve
species from southern Chile. Results of the “Victor Hensen’ cruise to the Magellan
Strait and the Beagle Channel in October/November 1994. Archive of Fishery and
Marine Research 44: 243-256.

Valdovinos, C. & Stuardo, J. 1995. Morfologia funcional de Chilina angusta (Philippi,
1860), y evolucién de Chilinidae. Resumos, II Congresso Latino-Americano de
Malacologia, Porto Alegre, Brasil: 43.

Vermeij, G. J. 1993. Spinucella, a new genus of Miocene to Pleistocene muricid
gastropods from the eastern Atlantic. Contributions to Tertiary and Quaternary
Geology 30: 19-27.

Villarroel, M. & Stuardo, J. 1998. Protobranchia (Mollusca: Bivalvia) chilenos
recientes y algunos fosiles. Malacologia 40: 113-229.

Viviani, C. A. 1979. Ecogeographia del litoral chileno. Studies on Neotropical Fauna
and Environment 14: 65-123.

Waller, T. R. 1991. Evolutionary relationships among commercial scallops (Mollusca:
Bivalvia: Pectinidae). pp. 1-73. In: Shumway, S. E. (ed.) Scallops: Biology, Ecology
and Aquaculture. Elsevier, Amsterdam.

Waloszek, D. 1984. Variabilitat, Taxonomie und Verbreitung von Chlamys patagonica
(King & Broderip, 1832) und Anmerkungen zu weiteren Chlamys-Arten von der
Siidspitze Siid-Amerikas (Mollusca, Bivalvia, Pectinidae). Verhandlungen des
Naturwissenschaftlichen Vereins in Hamburg 27: 207-276.

Waloszek, D. & Waloszek, G. 1986. Ergebnisse der Forschungsreisen des FFS
“Walther Herwig’ nach Siidamerika. LXV. Vorkommen, Reproduktion, Wachstum
und mégliche Nutzbarkeit von Chlamys patagonica (King & Broderip, 1832)
(Bivalvia, Pectinidae) auf dem Schelf vor Argentinien. Archiv fiir
Fischereiwissenschaft 37: 69-99.

Watson, R. B. 1886. Report on the Scaphopoda and Gasteropoda collected by H.M.S.
Challenger during the years 1873-76. Report on the Scientific Results of the Voyage
of H.M.S. Challenger During the Years 1873-76. Zoology 15: 1-756.

Weaver, C. S. & duPont, J. E. 1970. Living Volutes. 375 p. Delaware Museum of
Natural History, Greenville, Delaware.

Wu, S.-K. 1985. The genus Acanthina (Gastropoda: Muricacea) in west America.
Special Publication of the Mukaishima Marine Biological Station 1985: 45-66.

Bull. nat. Hist. Mus. Lond. (Zool.) 66(2): 147-166

Issued 30 November 2000

Remarks on the genera Schizocuma Bacescu,
1972 and Styloptocuma Bacescu & Muradian,

1974 (Crustacea, Cumacea)

SEE tal 3G

Ne

I, PETRESCU

Department of Invertebrates, ‘Grigore Antipa’ National Museum of Natural History, Kiseleff l, Bucharest

79744, Romania.

SYNOPSIS. Morphological data are presented to support the view that Schizocuma Bacescu, 1972 and Styloptocuma Bacescu &
Muradian, 1974 are good genera. Both genera exhibited a mixture of characters found in Cumella and Nannastacus, but share
more common with Cumella. Schizocuma and Styloptocuma appeared to have evolved in deeper waters, earlier than the rest of
Cumella group, having separated from a common stem with the Nannastacus group.

INTRODUCTION

Schizocuma Bacescu and Styloptocuma Bacescu & Muradian are
two deep-sea genera belonging to the family Nannastacidae. Cur-
rently available descriptions of the species in these genera are
incomplete, lacking data on the mouthparts or one of the sexes. In
the case of Schizocuma vemae, (known only from the holotype), the
type material has been lost. Both Schizocuma and Styloptocuma
have been subjects of systematic revisions by authors who have
either totally or partially invalidated them (Jones 1984, Watling
1991), or considered them to be good genera (Bacescu 1992, Holt-
huis 1990).

This study is based entirely on material loaned to the author by the
Department of Zoology of the Natural History Museum, London.

MATERIALS AND METHODS

The material examined consists of non type specimens of 8 species,
7 of which were described by Jones (1984); all were previously
identified by him and included in the genus Cumella. These speci-
mens were collected by different research vessels of Woods Hole
Oceanographic Institute.

Cumella acuminatum Jones, 1984 1992:700:30
86 specimens (females and immature males); collecting data —
Atlantis II 31, sta.156, 0° 46' S 29° 28' W, 3459 m, 14.2.1967.

Cumella antipai (Bacescu & Muradian, 1974) 1992:678:10
13 females, 3 males (2 adults and 1 immature); collecting data —
Knorr 25, sta.293, 8° 58' N 50° 04.3' W, 1518 m, 27.2.1972.

Cumella bishopi Jones, 1984 1992:677:30
44 females, 38 males (22 adults and 16 immatures); collecting data
— Knorr 25, sta.293, 8° 58' N 50° 04.3' W, 1518 m, 27.2.1972.

Cumella dayae Jones, 1984 1992:684:36
22 females, 17 males (5 adults and 12 immatures); collecting data —
Atlantis II 60, sta. 245, 36° 35.7’ S 53° O1' W, 2707 m, 14.3.1971.

Cumella echinata Jones, 1984 1992:685:20
18 females, 4 males; collecting data — Chain 106, sta. 313, 51° 32.2'
N 12° 35.9' W, 1500 m, 17.8.1972.

© The Natural History Museum, 2000

Cumella formosa Jones, 1984 1992:676:4
3 females, 1 immature male, 1 manca; collecting data — Atlantis II
60, sta. 245, 36° 55.7' S 53° 61.4' W, 2707 m, 14.3.1971.

Cumella spinoculata Jones, 1984 1992:783:7
3 females, 2 males and 2 juv.; collecting data — Chain 106, sta. 313,
ple 32-2) N22 35.9 W500 im, 172821972:

Cumella vemae (Bacescu & Muradian, 1974) 1992:777:4
1 female, 2 immature males; collecting data— Atlantis II 31, sta.167,
7°58 S945 07 W: 1007 mi; 20.2.1967.

13 specimens in glycerine-alcohol on slides were dissected for
this study. Measurements were taken with an ocular micrometer, and
all the slides are deposited in the collections of the Natural History
Museum, London.

SYSTEMATIC REMARKS

Genus SCHIZOCUMA Biacescu, 1972

Schizocuma Bacescu, 1972: 246.
Cumella Jones, 1984: 210-211.
Schizocuma Watling, 1991: 755.
Schizocuma Bacescu, 1992: 258-259.

TYPE SPECIES. Schizocuma vemae Bacescu, 1972.

DIAGNOSIS. Carapace short (one-fifth the length of pleon with
uropods), without carinae, with long hairs in males and dorsal spines
in females (also on the ocular lobe); antero-ventral corner rounded
or subacute, antero- inferior edge slightly serrated. Median ocular
lobe incompletely subdivided. Branchial siphons separated, located
medially to dorsolaterally; pseudorostral lobes widely separated.
Pleonites long and thin, their length increasing distally up to the
fifth, which is 5.5 times longer than broad. Pleotelson short. An-
tenna | without tubercle on 2™ article of peduncle, subequal in
length or longer than 3", accessory flagellum 2-articulated. Antenna
2 with short flagellum. Pars incisiva of mandible with 4 teeth, lacinia
mobilis, thin, with 3 teeth, not exceeding pars incisiva, five long
plumose lifting setae between lacinia mobilis and truncated, robust,
pars molaris. Maxilla 1 with simple robust acuminate setae on

148

I. PETRESCU

Fig. 1 Schizocuma spinoculatum (Jones, 1984) immature male A. antenna 1; B. antenna 2; C. mandible; D. maxilla 1; E. maxilla 2; F. maxilliped 1; G.

maxillipd 2. Scale bars (in mm): A 0.1; B 0.2; C-F 0.1; G 0.1.

nea on

SCHIZOCUMA AND STYLOPTOCUMA

149

Fig. 2 Schizocuma spinoculatum (Jones, 1984) A-E. immature male; F, G. female A. maxilliped 3; B. pereopod 1; C. pereopod 2; D. pereopod 3; E.
uropod; F. maxilliped 3; G. pereopod 1. Scale bars (in mm): A, E 0.1; B, C, F, G 0.2; D 0.2.

150

protopod, palp with 2 filaments. Maxilla 2 with two endites, fine
simple setae on endites and outer margins of protopod. Basis of
maxilliped 1 with an outer endite not exceeding merus, carpus with
flattened hand-like setae on outer margin of carpus, rounded, en-
larged dactylus. Basis of maxilliped 2, longest article, merus bulky,
carpus longer than all articles excepting basis, with short plumose
setae on outer margin, dactylus with an apical claw. Maxilliped 3
with short inner process. Exopods on maxilliped 3 and pereopods 1—
2 in females and on maxilliped 3 and pereopods 1-4 in males.
Uropod peduncle much longer than pleonite 6 and its rami, uropod
exopod basal article normal, endopod as long as, or slightly longer
than exopod.

GENDER. Neuter.

ADDITIONAL SPECIES. Schizocuma calmani (Stebbing, 1912), S.
molossa (Zimmer, 1907), S. spinoculatum (Jones, 1984), S. spinosum
(Jones, 1984).

REMARKS. Bacescu (1972) considered Schizocuma to be distin-
guishable from Cumella only by the separated siphons and
slenderness and elongation of the body and appendages. Jones
(1984) argued that there is a gradation in body and appendage form
and there are not sufficient criteria to recognise Schizocuma as a
separate genus. Watling (1991) added to the characters presented by
Bacescu, including dorso-lateral pseudorostral lobes and unique
ocular lobe, and considered Schizocuma as a valid genus. The study
of the mandible and maxilliped 1 revealed that there are also
distinctive characters that clearly separate Schizocuma from Cumella:
pars incisiva of mandible with 4 teeth (versus 3 in Cumella),
dactylus of maxilliped 1 rounded and enlarged versus acuminate and
small in Cumella. These last characters and the separated
pseudorostral lobes and siphons are more similar to the Nannastacus
group (Nannastacus, Scherocumella, Schizotrema), but the others
(unique eye lobe, peduncle of antenna | without tubercle, maxilliped
2 with slender plumose setae on propodus, uropods with long
peduncles) are more like Cumella. Watling (1991) mentioned in the
list of the additional species of this genus the species Schizocuma
divisa (Jones, 1984). In my opinion this species belongs to the genus
Cumella (as described by Jones) because of its non-separated si-
phons, fairly short pleon and a uropodal peduncle 1.5 longer than its
rami (shorter than in Schizocuma).

Schizocuma spinoculatum (Jones, 1984)
Figs 1, 2

Cumella spinoculata Jones, 1984: 219-220.
Schizocuma spinoculata Watling, 1991: 755.
Schizocuma spinoculatum Bacescu, 1992: 258-259.

DESCRIPTION. To the original description I am adding add the
following morphological data on the immature male (not mentioned
by Jones). Antenna | (Fig. 1 A) with spine on 1“ article of peduncle,
2™ article a little longer than 3", accessory flagellum 2-articulate.
Antenna 2 (Fig. | B) characteristic for an older stage, with short
flagellum, but most articles well developed. Mandible (Fig. 1 C),
pars incisiva with 4 teeth, lacinia mobilis with 3 teeth, robust pars
molaris with a tooth-like process on its distal outer corner. Maxilla
1 (Fig. 1 D), protopod with 9 acuminate setae, palp with 2 unequal
filaments, the longest backwardly setulated in its- proximal half.
Maxilla 2 (Fig. 1 E) with simple setae on endites that exceed
protopod and margins of protopod. Maxilliped 1 (Fig. 1 F), with
endite of basis not exceeding extremity of merus, with strong
plumose setae, acuminate setae and retinacula; flattened hand-like
setae on outer margin of carpus, with rounded extremity; propodus

I. PETRESCU

a little longer than dactylus (propodus/dactylus= 1.4), rounded and
enlarged dactylus with few apical setae. Maxilliped 2 (Fig. 1 G),
basis a third of the entire maxilliped, bulky merus, carpus, the
longest article excepting basis, propodus with plumose setae on
outer distal corner, dactylus as long as his strong claw. Maxilliped 3
(Fig. 2 A), basis, stronger than in female, with a very short inner
process. Pereopod 1 (Fig. 2 B), basis without spines as in female,
carpus as long as propodus. Pereopod 2 (Fig. 2 C), with stronger
basis, a stiff acuminate seta on outer distal corner of carpus (fine,
simple setae in female), dactylus a little longer than in female
(dactylus/propodus= 2.5). Pereopod 3 (Fig. 2 D), basis longer than
half of pereopod, dactylus with long terminal seta. Uropod (Fig. 2 E),
peduncle much longer than last pleonite (1.85) and its rami (1.80),
exopod a little shorter than endopod, with a terminal seta, endopod
with 4 short setae on inner margin and a terminal robust short one.

Jones (1984) description of the female is amended to include the
following details: Maxilliped 3 (Fig. 2 F), basis with short inner
process, merus also without any process, a little longer than dacty-
lus, dactylus with an apical, strong, claw, longer than the article.
Pereopod | (Fig. 2 G), basis shorter than half of the entire pereopod,
2 acuminate setae on distal outer corner, carpus shorter than propodus,
dactylus with a claw longer than it. Pereopod 2 (Fig. 2 G), basis
shorter than half of the entire pereopod, dactylus 2.4 times longer
than propodus, with short simple terminal setae.

Schizocuma vemae Bacescu, 1972
Figs 3, 4

Schizocuma vemae, Bacescu, 1972: 246.
Cumella vemae, Jones, 1984: 214
Schizocuma vemae, Watling, 1991: 755
Schizocuma vemae, Bacescu, 1992: 258-259.

DESCRIPTION. To the description of the female in Jones (1984) the
following additional observations: Carapace (Fig. 3 A) with one
dorsal spine (up to 4 in Jones). Pereopod | (Fig. 3 B), basis shorter
than half of entire pereopod, carpus a little shorter than propodus,
dactylus shorter than its claw. Pereopod 2 (Fig. 3 C), basis shorter
than half of entire pereopod, a stiff acuminate seta on outer distal
corner of carpus as long as propodus, dactylus 4.3 times longer than
propodus, with simple setae. Pereopod 3 (Fig. 3 D), with thin and
long articles, basis as long as half of entire pereopod, carpus 3.2
times longer than propodus, dactylus with a long terminal seta.
Uropod (Fig. 3 E), peduncle very long (4 times longer than last
pleonite), peduncle/rami = 2.5; exopod as long as endopod, with a
terminal seta, endopod with simple setae and subterminal acuminate
seta on inner margin and a terminal, thin acuminate seta.

The description of an immature male by Bacescu (1972) was also
incomplete. The following details are added: Antenna 1 (Fig. 3 F),
peduncle articles long and thin, 2™ article longer than 3", accessory
flagellum, 2-articulate, shorter than basal article of main flagellum.
Antenna 2 (Fig. 3 G), characteristic of an immature male. Mandible
(Fig. 3 H), pars incisiva with 4 teeth, lacinia mobilis with 3 teeth,
robust, truncated pars molaris with a tooth-like process. Maxilla 1
(Fig. 4 A), protopod with 9 acuminate setae, palp with 2 unequal
filaments, the longest one is backwardly setulated. Maxilla 2 (Fig. 4
B), as usual for the genus. Maxilliped 1 (Fig. 4 C), carpus with
flattened hand-like setae with acute extremity, propodus 3.3 times
longer than dactylus, dactylus with apical fine, small setae. Maxilliped
2 (Fig. 4 D), with robust articles, as is usual for the genus. Pereopod
3 (Fig. 4 E), carpus 2.5 times longer than propodus, dactylus with a
long, curved acuminate seta. Pereopod 4 (Fig. 4 F), basis thinner,
carpus longer than in the previous pair (3 times longer), dactylus

SCHIZOCUMA AND STYLOPTOCUMA

Se ws
oe

Fig. 3 Schizocuma vemae Bacescu, 1972 A-E. female; F—H. immature male A. body, lateral view; B. pereopod 1; C. pereopod 2; D. pereopod 3; E.

uropod; F. antenna 1; G. antenna 2; H. mandible. Scale bars (in mm): A 1; B 0.25; C, D 0.3: E 0.3: F, G0.2:H0.1.

151

152 I. PETRESCU

Fig. 4 Schizocuma vemae Bacescu, 1972 immature male A. maxilla 1; B. maxilla 2; C. maxilliped 1; D. maxilliped 2; E. pereopod 3; F. pereopod 4; G.
pereopod 5; H. uropod. Scale bars (in mm): A—D 0.1; E—G 0.2; H 0.3.

SCHIZOCUMA AND STYLOPTOCUMA

also with a terminal, long, curved acuminate seta. Pereopod 5 (Fig.
4 G), basis as long as half of entire pereopod, carpus about 2 times
longer than propodus. Uropod (Fig. 4 H), peduncle shorter than in
female (2:1), 2 times longer than its rami, exopod as long as
endopod, with a long terminal seta, endopod with a subterminal long
simple seta and a terminal acuminate seta.

REMARKS. It does not seem possible to establish a neotype for the
species because the specimens from the British collection, although
from the same deep western Atlantic, are far (7° 58' S 34° 17' W)
from the type locality (27° 7' N 77° 08' W).

Key for the identification of Schizocuma species

iS pines Omicarapace and CYEe 1ODE....,....--..c.cc.-ssescercsncsesenceeseacenseereenvases 2
MESON CalapAace OF OM CVE LODE: ...<....c.cnncears<0-ceeadeccevsnsestonevaceonoweses 4
2 Dorsal spines on the whole carapace ...........:::sccssssesseescssescenseaeeseeeeees 3

— Dorsal spines only on the posterior part of carapace ............::.cceeeeeee
OUR cris ante ascohsensaus asszsevedsedeusesesnceswovsete S. molossa (Zimmer, 1913)

3 Double rows of spines on carapace ............ S. spinosum (Jones, 1984)
— Single row of spines on carapace ............ S. calmani (Stebbing, 1912)
4 __ Spines only on eye lobe ..............:::ee S. spinoculatum (Jones, 1984)
=P SPINES ONLY OM CaraPaCe ...........00-seeceeeeceesencees S. vemae Bacescu, 1972

Genus STYLOPTOCUMA Bacescu & Muradian, 1974

Styloptocuma Bacescu & Muradian, 1974: 74-75.
Cumella Ledoyer, 1983: 77.

Cumella Jones, 1984: 210-211.

Cumella (Styloptocuma) Watling, 1991: 752
Styloptocuma Bacescu, 1992: 262-265.
Styloptocuma Holthuis, 1992: 264.

Cumella Ledoyer, 1997: 869 — 876.

TYPE SPECIES. S. antipai Bacescu & Muradian, 1974.

DIAGNOSIS. Very elongate cumacean, with numerous spines on
entire body or only on carapace, long upturned pseudorostrum, long,
styliform eye lobe that could reach or even exceed the extremity of
pseudorostrum, without any traces of visual elements. Antenna |
with a very long basal peduncle article (longer than half of pedun-
cle), second article with a tubercle, main flagellum with two long
articles, accessory flagellum with two articles, shorter than the first
article of main flagellum. Pars incisiva of mandible with 4 teeth,
lacinia mobilis with 4 (rarely 3) teeth, long stiff setae between
lacinia mobilis and robust pars molaris (without any tubercles).
Maxilla 1 with robust acuminate setae on protopod, palp with 2
filaments. Maxilla 2 with endites, possibly with a row of fine, small
setae between the outer margin of protopod and endites. Maxilliped
1 with basis never exceeding extremity of merus, carpus with hand-
like setae on outer margin, long propodus and rounded dactylus.
Maxilliped 2 with long and slender basis, propodus with two plumose
setae on distal outer corner, dactylus with terminal setae. Maxilliped
3 without inner process of basis, propodus longest article excepting
basis, dactylus with terminal claws or setae. Pereopods and uropods
very slender. Number of exopods — 3 in female, 5 in male.

GENDER. Neuter.

ADDITIONAL SPECIES. S. aculeatum (Jones, 1984), S$. acuminatum
(Jones, 1984), S. angustatum (Jones, 1984), S. concinnum (Jones,
1984), S. bishopi (Jones, 1984), S. cristatum (Jones, 1984), S. dayae

153

(Jones, 1984), S. echinatum (Jones, 1984), S. egregium (Hansen,
1920), S. erectum (Jones, 1984), S. extans (Jones, 1984), S. formosum
(Jones, 1984), S. gracillimum (Calman, 1905), S. inermis (Ledoyer,
1997), S. longisipho (Jones, 1984), S. subductum (Jones, 1984).

REMARKS. Jones (1984) considered Styloptocuma to be a syno-
nym of Cumella because there did not seem to be any characters that
could be used to separate the genus (pseudorostrum, eye lobe, form
of body, antennule, pereopods and uropods). The absence of
mouthparts, especially maxilliped 1, from the descriptions, and no
importance accorded to the tubercle on the antennule, also caused
Ledoyer (1983, 1997) to adopt Jones’ view. In his revision of some
genera of nannastacids based on earlier descriptions, Watling 1991
concluded that Styloptocuma could be considered a subgenus of
Cumella. Holthuis (1992) discussed only the designation of the type
species of this genus and accepted the concept of Styloptocuma in
Bacescu & Muradian (1974) without any further comment.
Styloptocuma possesses a mixture of characters that unite it with
most of the Cumella group — non-separated pseudorostral lobes, a
unique eye lobe, form of carapace, lacinia mobilis of mandible with
3 teeth, propodus of maxilliped 2 with setae, thin pereopods, long
uropods; and to the Nannastacus group — antenna | with tubercle,
mandible with 4 teeth on pars incisiva and lacinia mobilis, long,
rounded dactylus of maxilliped 1. Maxilla 2 has features of both
groups (the transeverse row of setules on the protopod is character-
istic for the Nannastacus group; absent in Cumella). This genus
seems to link these groups and therefore has a unique set of characters.

Styloptocuma acuminatum (Jones, 1984)
Figs 5,6

Cumella acuminata Jones, 1984: 220-221.
Cumella (Styloptocuma) acuminata Watling, 1991: 752.
Styloptocuma acuminatum Bacescu, 1992: 262.

DESCRIPTION. A brief description of the distinctive characters of
the immature male not mentioned by Jones is given. Antenna 2 as in
Fig. 5 B. Maxilliped 3 (Fig. 5 C) has a longer basis and dactylar claw
than in the female. Pereopod | (Fig. 5 D) with an acuminate seta on
outer distal corner of basis. Pereopod 2 (Fig. 5 E) with teeth on outer
margin of basis and a shorter dactylus (shorter than carpus). Pereopods
3 and 4 (Fig. 5 F, G) with exopods, carpus longest article of pereopod
excepting basis, dactylus with a long curved terminal seta. Pereopod
5 (Fig. 5 H) with the shortest basis of all pereopods, carpus shorter
than in pairs 3 and 4. Uropod (Fig. 5 I) with peduncle 1.2 longer than
the last pleonite and 1.8 times longer than its rami; subequal rami,
exopod with a terminal short acuminate seta, endopod with 5 slender
acuminate setae on inner margin and a short terminal robust acumi-
nate seta.

To the description of female in Jones (1984) the following details
are added: Antenna | (Fig. 5 J, K) with a tubercle on the 2™ article
of the peduncle. Mandible (Fig. 5 L), pars incisiva with 4 teeth,
lacinia mobilis with 4 teeth (one of them very small), truncated pars
molaris. Maxilla 1 (Fig. 6 A) with robust acuminate setae on
protopod and palp with 2 filaments, the longest being backwardly
setulated in its proximal half. Maxilla 2 (Fig. 6 B) without a row of
fine, small setae between endites and outer margin of protopod.
Maxilliped 1 (Fig. 6 C) with a bifid robust acuminate seta on endite
of basis, carpus with hand-like flattened setae with 6 denticles,
dactylus smaller than propodus, enlarged, with excavated distal
margin. Maxilliped 2 (Fig. 6 D), slender basis, carpus longest article
excepting basis, propodus with plumose setae, dactylus with a
curved claw. Maxilliped 3 (Fig. 6 E), basis without inner process,
dactylus with terminal setae. Pereopod 3 (Fig. 6 H), with slender

154 I. PETRESCU

Fig.5 — Styloptocuma acuminatum (Jones, 1984) A-I. immature male; J — L. female A. body, lateral view; B. antenna 2; C. maxilliped 3; D. pereopod 1; E.
pereopod 2; F. pereopod 3; G. pereopod 4; H. pereopod 5; I. uropod; J. antenna 1; K. antenna 1, detail; L. mandible. Scale bars (in mm): A 0.5; B, D-J
O2ZAC OW AKON OL05:

SCHIZOCUMA AND STYLOPTOCUMA

155

Fig. 6 Styloptocuma acuminatum (Jones, 1984) female A. maxilla 1; B. maxilla 2; C. maxilliped 1; D. maxilliped 2; E. maxilliped 3; F. pereopod 1; G.
pereopod 2; H. pereopod 3; I. pereopod 4; J. pereopod 5. Scale bars (in mm): A 0.1; B—D 0.05; E—J 0.2.

156

articles, basis shorter than half of pereopod, carpus longest article
of pereopod excepting basis, dactylus with a long curved apical seta.
Pereopod 4 (Fig. 6 I), similar to the previous pair. Pereopod 5 (Fig.
6 J) with the smallest basis of all pereopods and with carpus longer
than in the pairs 3 and 5.

REMARKS. Pereopod | (Fig. 6 F) has a basis with two teeth on
outer margin (absent in description given in Jones 1984). Pereopod
2 (Fig. 6 G) has a shorter dactylus than is suggested in the original
description.

Styloptocuma antipai Bacescu & Muradian, 1974
Fig. 7

Styloptocuma antipai Bacescu & Muradian, 1974: 74-75.
Cumella antipai Jones, 1984: 214.

Cumella (Styloptocuma) antipai Watling, 1991: 752
Styloptocuma antipai Bacescu, 1992: 262.

DESCRIPTION. The description of an immature male including the
mouth appendages is given. Mandible (Fig. 7 A) as in S. acuminatum.
Maxilla 1 (Fig. 7 B) with glabrous filaments. Maxilla 2 (Fig. 7 C) as
in S. acuminatum. Maxilliped 1 (Fig. 7 D) with hand-like flattened
setae on carpus (different form than in S. acuminatum), rounded and
enlarged dactylus. Maxilliped 3 (Fig. 7 E) as in female described by
Bacescu & Muradian (1974). Pereopod 1 (Fig. 7 F), with carpus as
long as propodus instead of carpus shorter than propodus of female
(as given in Bacescu & Muradian 1974 and Jones 1984). Pereopod
2 (Fig. 7 G), as in female, but with glabrous margins of basis and
dactylus with a shorter terminal seta. Pereopod 3 (Fig. 7 H), basis
half of pereopod, dactylus with a terminal strong curved claw.
Pereopods 1-4 with exopods. Uropod (Fig. 7 I), peduncle 2 times
longer than the last pleonite, 1.5 times longer than its rami, inner
margin serrated; subequal rami, exopod with simple setae on both
margins and a long terminal one, endopod with three acuminate
setae on inner margin and a terminal robust acuminate seta a little
shorter than on exopod.

Styloptocuma bishopi (Jones, 1984)
Figs 8, 9

Cumella bishopi Jones, 1984: 233.
Cumella (Styloptocuma) bishopi Watling, 1991: 752
Styloptocuma bishopi Bacescu, 1992: 263.

DESCRIPTION. A description of immature male is given. Antenna
1 (Fig. 8 A), 1“ article of peduncle shorter than remaining articles,
2™ article with a tubercle with pedunculate setae. Mandible (Fig. 8
B), pars incisiva with 4 teeth, robust lacinia mobilis with 3 teeth,
truncated pars molaris. Maxilla 1 (Fig. 8 C), as in S. antipai, with
glabrous filaments. Maxilla 2 (Fig. 8 D), with a row of fine, small
setae between endites and outer margin of protopod. Maxilliped 1
(Fig. 8 E), endite of basis with 2 spatulate setae, carpus with hand-
like flattened setae with 6 denticles, rounded dactylus. Maxilliped 2
(Fig. 8 F), as usual for the genus. Maxilliped 3 (Fig. 8 G), basis and
merus without teeth. Pereopod 1 (Fig. 8 H), as in female. Pereopod
2 (Fig. 8 I), as in female, with larger basis. Pereopod 3 (Fig. 9 A),
basis half of pereopod, carpus 2 times longer than propodus. Pereopod
4 (Fig. 9 B), basis shorter than half of pereopod, carpus 3 times
longer than propodus. Pereopod 5 (Fig. 9 C), slender articles, carpus
3.8 times longer than propodus.

The description in Jones (1984) is augmented with the following
details: Pereopod 3 (Fig. 9 G), basis half of pereopod, with serrated
outer margin, carpus/propodus = 1.6, dactylus with a short curved

I. PETRESCU

claw. Pereopod 4 (Fig. 9 H), basis shorter than half of pereopod, with
a serrated outer margin, longer carpus (carpus/propodus = 2.5).
Pereopod 5 (Fig. 9 I), basis shorter than half of pereopod, with
serrated outer margin, carpus longer than in the pairs 3 and 4 (carpus
/propodus= 2.8).

REMARKS. Differences noted in specimens examined for this study
include: maxilliped 3 (Fig. 9 D) with a tooth on inner margin of
merus, pereopod 1 (Fig. 9 E) with teeth also on the outer margin,
carpus longer than propodus (versus carpus shorter than propodus),
pereopod 2 (Fig. 9 F), with 2 stiff acuminate setae on outer distal
corner of carpus (instead of simple setae).

Styloptocuma dayae (Jones, 1984)
Figs 10, 11

Cumella dayae Jones, 1984: 226-227.
Cumella (Styloptocuma) dayae Watling, 1991: 752.
Styloptocuma dayae Bacescu, 1992: 263

DESCRIPTION. The description of the female is supplemented with
additional data on antenna 1, mouthpieces and maxillipeds 1, 2 and
pereopods 3-5. Antenna | (Fig. 10 A), 2™ article of peduncle with a
short tubercle. Mandible (Fig. 10 B), pars incisiva with 4 teeth (one
of them is very short), strong lacinia mobilis with 3 teeth. Maxilla 1
(Fig. 10 C), protopod with robust acuminate setae and palp with 2
glabrous filaments. Maxilla 2 (Fig. 10 D), no row of fine, small setae
between endites and outer margin of protopod. Maxilliped 1 (Fig. 10
E), carpus with hand-like flattened setae with 4 denticles, rounded
and enlarged dactylus. Maxilliped 2 (Fig. 10 F), as usual for the
genus. Pereopod 3 (Fig. 10 G), basis longer than half of pereopod,
tiny dactylus with a long terminal seta. Pereopod 4 (Fig. 10 H), basis
shorter than half of pereopod, carpus shorter than in the previous
pair. Pereopod 5 (Fig. 10 I), basis shorter than half of pereopod,
carpus longer than in pairs 3 and 4.

Some details on the structure of the immature male are also
provided. Maxilliped 3 (Fig. 11 A), basis without the short process
mentioned by Jones for the female. Pereopods | and 2 (Fig. 11 B, C),
as in female. Pereopod 3 (Fig. 11 D), basis half of pereopod, carpus/
propodus: 1.8, tiny dactylus with long terminal seta. Pereopod 4
(Fig. 11 E), basis shorter than half of pereopod, carpus/propodus:
1.7. Pereopod 5 (Fig. 11 F), basis shorter than carpus, carpus/
propodus: 3.1.

Styloptocuma echinatum (Jones, 1984)
Figs 12, 13

Cumella echinata Jones, 1984; 223-224.
Cumella (Styloptocuma) echinata Watling, 1991: 752.
Styloptocuma echinatum Bacescu, 1992: 263.

DESCRIPTION. This species was incompletely described in Jones
(1984), his description being based only the female. Additional
details for immature males and females are included here. Jmmature
male — Antenna | (Fig. 12 A), 1“ article of peduncle twice longer
than the rest of antenna, 2" article with a tubercle. Mandible (Fig. 13
B), pars incisiva with 4 teeth, lacinia mobilis also with 4 teeth (one
of them very short). Maxilla 1 (Fig. 13 C), palp with 2 glabrous
filaments. Maxilla 2 (Fig. 13 D), long fine setae on outer margin of
protopod, but not between its outer margin and endites. Maxilliped
1 (Fig. 13 E), carpus with hand-like flattened setae with 4 denticles,
rounded and enlarged dactylus. Maxilliped 2 (Fig. 13 F), as usual for
the genus. Maxilliped 3 (Fig. 13 G), basis without inner process,
dactylus with 2 claws. Pereopod 1 (Fig. 13 H), basis with rows of

SCHIZOCUMA AND STYLOPTOCUMA 157

Fig. 7 Styloptocuma antipai Bacescu & Muradian, 1974 immature male A. mandible; B. maxilla 1; C. maxilla 2; D. tip of maxilliped 1; E. maxilliped 3; F.
pereopod 1; G. pereopod 2; H. pereopod 3; I. uropod. Scale bars (in mm): A — D 0.05; E—H 0.1; 10.2.

158

I. PETRESCU

i

ZS

SE.

ae

Fig. 8 Styloptocuma bishopi (Jones, 1984) immature male A. antenna 1; B. mandible; C. maxilla 1; D. maxilla 2; E. maxilliped 1; F. maxilliped 2; G.
maxilliped 3; H. pereopod 1; I. pereopod 2. Scale bars (in mm): A 0.1; B—E 0.05; F 0.1; G—10.2.

SCHIZOCUMA AND STYLOPTOCUMA

Fig.9 Styloptocuma bishopi (Jones, 1984) A — C. immature male; D —I. female A. pereopod 3; B. pereopod 4; C. pereopod 5; D. maxilliped 3; E.
pereopod 1; F. pereopod 2; G. pereopod 3. H. pereopod 4; I. pereopod 5. Scale bars (in mm): A —C, E, F—1 0.2; D 0.2.

59

160

I. PETRESCU

Fig. 10 Styloptocuma dayae (Jones, 1984) female A. antenna 1; B. mandible; C. maxilla 1; D. maxilla 2; E. maxilliped 1; F. maxilliped 2; G. pereopod 3;
H. pereopod 4: I. pereopod 5. Scale bars (in mm): A 0.2; B, E 0.05; C, D 0.05; F 0.1.

teeth on both margins, very long and slender carpus and propodus,
carpus a little longer than propodus. Pereopod 2 (Fig. 14 A), carpus
with teeth on inner margin and with 2 stiff acuminate setae on outer
distal corner, dactylus 3 times longer than propodus, with simple
setae. Pereopod 3 (Fig. 14 B), basis longer than half of pereopod,
carpus/propodus: 1.9, tiny dactylus with a long curved terminal seta.
Pereopod 4 (Fig. 14 C), basis shorter than half of pereopod, carpus/

propodus: 2.9, dactylus as in previous pair. Pereopod 5 (Fig. 14 D),
basis shorter than half of pereopod, carpus/propodus: 1.6, same type
of dactylus.

Female —Maxilliped 3 (Fig. 14 E), as in male. Pereopod 1 (Fg. 14 F),
teeth only on outer margin of basis, carpus shorter than propodus.
Pereopod 2 (Fig. 14 G), as in male. Pereopods 3-5 (Fig. 14 H—J),

SCHIZOCUMA AND STYLOPTOCUMA 161

Fig. 11 Styloptocuma dayae (Jones, 1984) immature male A. maxilliped 3; B. pereopod 1; C. pereopod 2; D. pereopod 3; E. pereopod 4; F. pereopod 5.
Scale bar (in mm): A —F 0.3.

very elongated and slender, with the same ratio between articles as Cumella formosa Jones, 1984: 231-233.
in male. Cumella (Styloptocuma) formosa Watling, 1991: 752.
Styloptocuma formosum Bacescu, 1992: 264.

2 OUTSET) OSES EDO ESIEAE) DESCRIPTION. To the description of the adult female in Jones

Figs 14, 15 (1984) the following details are added: Antenna 2 (Fig. 14 B), with

162 I. PETRESCU

Fig. 12 Styloptocuma echinatum (Jones, 1984) immature male A. antenna 1; B. mandible; C. maxilla 1; D. maxilla 2; E. maxilliped 1; F. maxilliped 2; G.
maxilliped 3; H. pereopod 1. Scale bars (in mm): A 0.1; B—E 0.05; F 0.1; G 0.1; H 0.2.

SCHIZOCUMA AND STYLOPTOCUMA 163

Fig. 13 Styloptocuma echinatum (Jones, 1984) A — D. immature male; E-J. female A. pereopod 2; B. pereopod 3; C. pereopod 4; D. pereopod 5; E.
maxilliped 3; F. pereopod 1; G. pereopod 2; H. pereopod 3; I. pereopod 4; J. pereopod 5. Scale bars (in mm): A —D 0.3; E 0.5; F—J 0.5.

164 I. PETRESCU

Fig. 14 Styloptocuma formosum (Jones, 1984) female A. antenna 1; B. antenna 2; C. mandible; D. maxilla 1; E. maxilla 2; F. maxilliped 1; G. maxilliped
2. Scale bars (in mm): A, B 0.1; C-G0.1.

SCHIZOCUMA AND STYLOPTOCUMA 165

Fig. 15 Styloptocuma formosum (Jones, 1984) female A. maxilliped 3; B. pereopod 1; C. pereopod 2; D. pereopod 3; E. pereopod 4; F. pereopod 5. Scale
bars (in mm): A 0.25; B—F 0.3.

166

2 articles and 2 plumose and one simple setae. Mandible (Fig. 14 C
), pars incisiva and lacinia mobilis with 4 teeth . Maxilla | (Fig. 14
D), palp with 2 glabrous filaments. Maxilla 2 (Fig. 14 E), a row of
fine, small setae between outer margin of protopod and endites.
Maxilliped 1 (Fig. 14 F), carpus with hand-like flattened setae with
6 denticles, more fully developed and rounded dactylus. Maxilliped
2 (Fig. 14 G), with robust articles, propodus with plumose setae.
Maxilliped 3 (Fig. 15 A), basis with a very short inner process,
setules on outer margins of basis and carpus. Pereopods 3—5 (Fig. 15
D-F), basis with teeth on inner margin, 3™ pair with longer basis, 5"
one with longer carpus, short dactylus with long curved terminal
seta.

REMARKS. Antenna | (Fig. 14 A) as described in Jones (1984).
Pereopod | (Fig. 15 B) has teeth on outer margin and 2™ pair (Fig. 15
C) has teeth on inner margin (versus glabrous in Jones).

Key for the identification of Styloptocuma species

1 Eye lobe not exceeding pseudorostrum .............:0:csceseesessereesereees 2
- ByevlobeexceedingspsendOnOs tiie recseeee eee ee ener ees 14
2 Pseudorostrum passes beyond the level of the anterior corner.... 3

- Pseudorostrum not or scarcely passing beyond the level of the
ANCESTOR COMMER: 2 sciscwzisves Gacceuceut vacsei Rance ssctbesSeenceredecencre eons 3)

3 Rows of spines on lateral sides of pleom ..............:.::eccsseseeseeeeeee 4

- Without spines on lateral sides of Pl€OM ..........-..:ceceeseeesteeeteeeeeeees
Be 2. tn er TN OE OR ae: screed S. aculeatum (Jones, 1984)

4 Spines on pseudorostrum, pereopods and uropods ...............-202-
1 5 SER ORT on aceaao i echicwrdacceos ee DOA S. echinatum (Jones, 1984)

= No spines on pseudorostrum, pereopods and uropod ...................-
Ask a AO Cn cs ee Site des Ae S. erectum (Jones, 1984)

3) Rows of spines on lateral sides of pleon .............::::csceseeeeeeeees 6
- Without spines on lateral sides of pleOn .............ccecceseeseseeeeeeeeeee 2)
6 Carapace wathidorsallispinesie-ss seas ete tees retere ees ecee I
- Carapace without dorsal spines ................ S. extans (Jones, 1984)
di Eye lobe reaching end of pseudorostrum ...........:..ccesecseeseeeeeeeeeees 8

- Eye lobe not reaching end of pseudorostrum ..............::e:ceseeeeeeeee
aa de eaaun Samah tous Desc cas sade eae tote S. concinnum (Jones, 1984)

8 Eye lobe with an apical spine ............... S. cristatum (Jones, 1984)
- Eye lobe without apical spine .............. S. formosum (Jones, 1984)

s) Carapacenwathid onsalts pine Sereseeaseaeseeeetet sce eeeeeese reese ree eee 10
- Carapacerwithoutspineswees crores eee eee ee 13
10 Carapace with double rows of dorsal spines .............:cccccecseeeeeeeees

Sacer eco Ceca LS IS aR oe S. subductum (Jones, 1984)
- Carapace with a single row Of SPINES ............:cececeeceeseeeneeeneeeneees 11
11 Uropodal peduncle 2 x longer than 6th pleonite ....................... 12

- Uropodal peduncle less than 2 x longer than 6th pleonite ............
Wee havea tat cs cucu siotcn tueut cava Sitters: oouencrsaerxae? S. acuminatum (Jones, 1984)

12 Carapace and uropods with many Spine ...........c:ccccceeseeeseenteeneeeee

= Carapace and uropods with fewer Spine .............s:sscceccescereereeeeeeee
Fide este oie iste eu ct sven scented eectareeestences S. gracillimum (Calman, 1905)

I. PETRESCU

13 Uropodal peduncle 2 x longer than 6th pleomit .............cceseseeeeees
PF ay Re rE a? pe ae iat S. angustatum (Jones, 1984)

Uropodal peduncle less than 2 x longer than 6th pleonite ............
Cece ee ERO EE ECE rere S. inermis (Ledoyer, 1997)

14 Pseudoros tiruirin |] Om Gos. case ioc cscn-sasveesttnaete- cn aczecs -esoe ss eee eens 15
- Pseudorostrum Short ...........:esceeeeeeees S. longisipho (Jones, 1984)
15 Two dorsal rows of spines On Carapace ............seeeseeeeeeteneeeeeeees 16

~ One dorsal row of of spines ON Carapace ...........-:.ssscesceeecesceceeceees
SededusbDauees chs deed oieseaws Pete isan eat S. egregium (Hansen, 1920)

16 Body and uropods densely spinose, pereopods less serrated ........
De a eras een been, Spe ails Aen S. antipai Bacescu & Muradian, 1974

- Body and uropods with fewer, shorter spines, pereopods more
S@irated ce cscccse Mes cece. cc Re ease S. bishopi (Jones, 1984)

PHYLOGENETIC REMARKS

Both Schizocuma and Styloptocuma with mixed characters seem to
be earlier separated from the branch of Cumella group than the other
genera (Almyracuma Jones & Burbanck, 1959, Atlantocuma Bacescu
& Muradian, 1974, Claudicuma Roccatagliata, 1981, Cumella Sars,
1865, Cumellopsis Calman, 1905, Elasocumella Watling, 1991,
Platycuma Calman, 1905) and evolved in specific ways in the deep
sea preserving more characters common with Nannastacus group
(Nannastacus Bate, 1865, Scherocumella Watling, 1991, Schizotrema
Calman, 1911), characters absent to the other deep sea mentioned
genera of the Cumella group. Styloptocuma seems to be closer to
Nannastacus within the group of Cumella than Schizocuma.

ACKNOWLEDGEMENTS. [am grateful to Miranda Lowe from the Depart-
ment of Zoology, The Natural History Museum, London, for the loan of the
studied material; to the late Acad. Mihai Bacescu for the valuable references
and discussions; to the late Norman Jones for suggestions regarding this
study and for suggesting a suitable institution for depositing the materials
studied by him; and to Aurora Dinu who inked the drawings.

REFERENCES

Bacescu, M. 1972. Archaeocuma and Schizocuma, new genera of Cumacea from the
American tropical waters. Revue Roumaine Biologie.Série Zoologie, 17 (4), 241—
250.

— 1992. Cumacea II (Fam. Nannastacidae, Diastylidae, Pseudocumatidae,
Gynodiastylidae et Ceratocumatidae), 8, 175 — 468. In: Gruner, H. E. & Holthuis L.
B. (eds) Crustaceorum Catalogus. SPB Academic Publishing, The Hague.

& Muradian, Z. 1974. Campylaspenis, Styloptocuma, Atlantocuma, new genera
of Cumacea from the deep waters of the Atlantic. Revue Roumaine Biologie. Biologie
Animale, 19 (2), 71-78.

Holthuis, L.B. 1990. Styloptocuma Bacescu & Muradian, 1974 (Crustacea, Cumacea):
proposed conservation with designation of S. antipai Bacescu & Muradian, 1974 as
the type species Bulletin Zoological Nomenclature, 49 (4), 264.

Jones, N.S. 1984. The family Nannastacidae (Crustacea, Cumacea) from the deep
Atlantic Bulletin British Museum (Natural History.) Zoology 46 (3), 207-289.

Ledoyer, M. 1983. Contribution 4 I’ étude de |’ écologie de la faune vagile profonde de
la Méditerranée nord-occidentale 2. Les Cumacés (Crustacea) Tethys, 11 (1), 77.

1997. Les Cumacés (Crustacea) des campagnes Eumeli 2., 3 et 4 au large du Cap
Blanc (est Atlantique tropical) Journal Natural History, 31, 841-886.

Watling, L. 1991. Rediagnosis and revision of some Nannastacidae (Crustacea:
Cumacea) Proceedings Biological Society Washington, 104 (4), 751-757.

Bull. nat. Hist. Mus. Lond. (Zool.) 66(2):167—170

Issued 30 November 2000

A new species of Sigambra (Polychaeta,
Pilargidae) from the abyssal plains of the

NE Atlantic

q - ‘

xy (230048. 1)

GORDON L J PATERSON AND ADRIAN G. GLOVER
Polychaete Research Group, Department of Zoology, The Natural History Museum, London SW7 5BD, UK.

INTRODUCTION

During an intensive study of the benthic communities of the
NE Atlantic abyssal plains (Rice et al. 1994), a new species of
Sigambra was identified. It was conspicuous in being one of the
more abundant species and certainly the dominant predator. The
species was widespread, being recorded from study sites from the
Cap Verde Abyssal Plain in the south to the Porcupine Abyssal Plain
in the north.

MATERIAL AND METHODS

All specimens were collected using a modified United States Naval
Electronics Laboratory. spade box corer (SBC). Samples from the
Porcupine, Madeira and Cape Verde Abyssal Plains were sectioned
horizontally into 0-1 cm, 1-3 cm and 3-5 cm layers and processed
through a number of sieves — 1, 0.5 and 0.3 mm. Samples from the
Tagus Abyssal Plain were taken with a vegematically modified box
corer and only the inner nine subcores were processed through a 0.3
mm sieve.

MATERIAL STUDIED

Specimens have been deposited in a number of taxonomic institu-
tions and corresponding registration numbers are given below.
Abbreviations: AM — The Australian Museum, Sydney; LA — Los
Angeles County Museum of Natural History; MNHN — Museum
National d’ Histoire Naturelle, Paris; BMNH — The Natural History
Museum, London; NMNH — National Museum of Natural History,
Smithsonian Institution; NMS — The National Museums of Scot-
land; NMW - The National Museum of Wales; ZH Zoologisches
Institut und. Museum, Hamburg; ZMUC — Zoological Museum,
Copenhagen.

Holotype: Porcupine Abyssal Plain Challenger II Criuse 111:
53201#29 48°51.5' N 16°29.6' W, 4844 m, sediment layer 1-3 cm
0.5mm sieve, 14/4/1994 (BMNH 2000. 1852).

Paratypes: Porcupine Abyssal Plain the following samples cen-
tred on 48°50' N 16°30' W in 4850 m:

Discovery Cruise 185: 11908#18: 1—3cm 0.3 mm sieve 1| ind. 28/8/
1989.

Challenger IT Cruise 79: 52701#5: 1-3 cm, 0.3mm sieve 4 ind.; 1—

3cm 0.5mm sieve 2 ind (NMSz: 2000.214).16/5/1991.

52701#9: 1-3 cm 0.5mm | ind (ZMH). 17/5/1991.

52701#25: 1-3 cm 0.3mm sieve | ind.(MNHN-POLY 53); 0-1 cm
0.5 mm sieve | ind (NMW.Z: 2000.070).; 3-5 cm 0.5mm sieve 2
ind (NMNH 186794). 20/5/1991;

52701#29: 1-3 cm 0.3 mm sieve | ind. (AM); 1 ind. (ZMUC-POL-
1013 21/5/1991.

© The Natural History Museum, 2000

52701#47 1-3 cm 0.3 mm sieve | ind. (LA) 21/5/1991.

Challenger Cruise 111: 53201#23 1-3 cm 0.3 mm 1 ind. 13/4/1994;
53201#26 1-3 cm 0.3 mm sieve | ind., 1-3 cm 0.5 mm sieve 2
ind., 3-5 cm 0.3 mm | ind. 14/4/1994;

53201 # 29 1-3 cm 0.25 mm sieve | ind., 1-3 cm 0.5 mm sieve |
ind., 3-5 cm 1 mm sieve ind. 14/4/1994;

53205#2 0.3 mm 0-1 cm sieve | ind., 3—5 cm 0.5 mm sieve | ind.,
18/4/94.

Tagus Abyssal Plain centred on 38°N 11°W 5035 m: Discovery
Cruise 186: SBC365 3 ind. 26/9/1989; SBC366 1 ind. 26/9/1989;
SBC367 5 ind. 26/9/1989; SBC368 5 ind., SBC369 2 ind. 27/9/
1989; SBC371 2 ind. 28/9/1989.

Madeira Abyssal Plain centred on 31°10' N 21°10' W 4985m:

Discovery Cruise 194: 12174#35: 1-3 cm 0.3 mm sieve 2 ind.: 1-3

cm (0.5 mm sieve | ind.; 3—5 cm 0.5 mm sieve 3 ind. 21/8/1990.

12174#43: 1-3 cm 0.3 mm | ind. 22/8/1990.

12174#53: 1-3 cm 0.3 mm sieve 2 ind. 23/8/1990

12174 #60: 1-3 cm 0.3 mm sieve | ind. 24/8/1990.

12174#80 0-1 cm 0.3 mm sieve | ind.; 5—10 cm 0.5 mm sieve | ind.
28/8/90.

Cape Verde Abyssal Plain centred on 20°N 30°W 4500-4600 m: Dis-
covery Cruise 204: 12600#32 0-1 cm 0.3 mm sieve | ind. 6/10/1994.

In addition the following material was examined: Sigambra bidentata
Britaev & Saphronova, 1981 Natural History Museum Polychaete
Collection Z1986:178-183 (5 paratypes), Vityaz Stn 7488 38°
41°N:133° 45’E 1550 m Sea of Japan. Sigambra gracilis Britaev &
Saphronova, 1981 ZR1986.184—185 (2 paratypes), Vostok Bay, Sea
of Japan. Sigambra phuketensis Licher and Westheide, 1997 Z1993.
15—16 (2 Paratypes), Bang Tao, W. Phuket Island, Thailand.

TAXONOMIC ACCOUNT

Family PILARGIDAE
Genus SIGAMBRA O.F.Miiller, 1858

Species S. magnuncus sp. nov.
(Figs 1-5)

DESCRIPTION
Holotype: Length 3.7 mm for 33 chaetigers, greatest width of
body 0.3 mm.
Paratypes: Range from length 0.5 mm for 13 chaetigers to 10.5
mm for 50 chaetigers, number of segments depends on size of
individual. (Fig. 5).

Body unpigmented; slightly flattened anteriorly, but becoming
more rounded posteriorly; anterior chaetigers widest.

168

939134 15K¥

om:

59128 i5Ky¥ &5

Fig.1 SEMs of Sigambra magnuncus (MAP Discovery Investigations
12174#60 0.5 mm sieve, 1—3 cm) A. General view of individual. B. View
of notopodia, note the small capillary chaeta in each notopodium

Prostomium rounded, slightly indented laterally at insertion of
palps and prostomium. Palps biarticulate with relatively long
palpostyles; palpophores fused distally over half their length. Three
antennae, median antenna longest, situated slightly posterior to

G.L.J. PATERSON AND A.G. GLOVER

959133 15K¥ 250 “120um

Fig. 2 SEMs of Sigambra magnuncus (MAP Discovery Investigations
12174#80 0.5mm sieve, 1-3 cm) Dorsal view of anterior region.

laterals in smaller specimens, but more level with them in larger
individuals. A pair of cushion like nuchal organs, situated on either
side of the median antennae. Eyes absent. Pharynx without jaws,
armed with eight equal size, slightly pointed papillae.
Peristomium approximately twice as long as first chaetiger. Two
pairs of long tapering tentacular cirri, dorsal cirri longer than ventral,
and slightly shorter than median antennae. A row of low cushion-
like papillae (sense organs) extending across dorsal surface of
peristomium (may only be visible under high magnification).

d
Cc

Fig. 3 a Parapodium from mid region, anterior view. b notopodial
hook, ¢ & d neurocapillaries. Scale bars = 0.1 mm.

A NEW N.E. ATLANTIC POLYCHAETE

A
P +
(3)
2
3 L
<=
) L
ro} + PAP/53201 L
3 © PAP
am TAP i
m €£0S li
| ° MAP
| © PAP/S3205 r
T T T T T =" > 1 ay T T T 1 To
(0) 2 4 6 8 10 12

Total Length (mm)

Fig. 4 Graph showing the relationship between size and number of
chaetigers. Individuals from different sample sites are identified. PAP—
Porcupine Abyssal Plain, MAP — Madeira Abyssal Plain, TAP — Tagus
Abyssal Plain, EOS — Cap Verde Abyssal Plain.

Parapodia biramous; anterior parapodia laterally orientated, be-

coming more dorsal in median and posterior chaetigers. A row of

cushion-like papillae extending across dorsal surface between
notopodia on each chaetiger.

Notopodia pointed, with straight, blunt-tipped internal aciculae.
Dorsal cirri of chaetiger 1 long, thin and tapering; nearly equal in
length to median antenna; subsequent dorsal cirri initially shorter
with wider bases, but in posterior chaetigers becoming more slender
longer and projecting dorsally. Large hooks emergent on chaetiger 3
(Fig. 1b, 2, 3b) until one or two chaetigers from pygidium; in
posterior chaetigers hooks meeting in midline. Short, delicate capil-
laries projecting from most notopodia, just one in anterior chaetigers
(Fig. 1b, 3a), usually becoming two in posterior segments.

Neuropodial lobes pointed, with blunt-tipped, straight aciculae
(Fig 3a); initially orientated laterally but become more vertical and
dorsal in posterior chaetigers. Ventral cirri absent on chaetiger 2; on

Se ER ES ee es ee ieee eee oe
|

2 L
oO
=!

3S L
2
ne)
£&
ro)

fe} Ke
Zz

=

ot Ime eal

0 2 4 6 8 10 12

Total Length (mm)

Fig.5 Histogram showing the range of sizes of S.magnuncus collected in
the NE Atlantic.

169

other chaetigers thin and tapering, equal to or shorter than neuro-
podia, equal to or slightly longer than dorsal cirri. Neurochaetae
simple capillaries, slightly expanded at the base just free of the
podia, tips quickly taper into a prolonged point (Fig. 3 c,d).
Pygidium with two tapering cirri. Anus dorsal.

DISTRIBUTION. S. magnuncus has been recorded from the abyssal
plains of the NE Atlantic at depths from 4000 m to 5085 m.

ETYMOLOGY. The name of this species derives from the large
conspicuous hooks on the notopodia (Latin magnus — large uncus —
hook).

DISCUSSION

Taxonomic Affinities

Licher & Westheide (1994) suggested that the Pilargidae was not a
separate family and that species in the family belonged in the
Hesionidae. This hypothesis has been rejected by Pleijel (1998) and
Pleijel and Dahlgren (1998) on the basis that Licher & Westheide’s
(1994) original study was not rooted in an appropriate outgroup.
Subsequent analysis by Pleijel and Dahlgren (1998) indicated that
the Pilargidae and Hesionidae were different and non-overlapping
groups. We, therefore, retain the family Pilargidae.

Including S. magnuncus, there are 17 described species of
Sigambra (Licher and Westheide, 1997). Based on examination of
Sigambra material in the NHM and the revision of Licher &
Westheide (1997), S$. magnuncus shares certain features with S.
ocellata (Hartmann-Schréder, 1959), S. bidentata Britaev &
Saphronova, 1981 and S. gingdaoensis Licher & Westheide, 1997,
namely the ventral cirrus is missing on chaetiger 2 and there are
eight papillae in the pharynx (Licher & Westheide, 1997). The
relative proportions of the dorsal and ventral cirri suggest similari-
ties with S. ocellata, however, in S. magnuncus the notopodial hooks
start on chaetiger 3 rather than chaetiger 6 as in S. ocellata. In
S. bidentata and S. gingdaoensis the notopodial hooks can start from
chaetigers 3, similar to S$. magnuncus, but in addition to differences
in cirral length, S. magnuncus differs from S. bidentata in not having
bidentate neurochaetae. S. magnuncus differs from S. gingdaoensis
in having one capillary notochaeta in anterior chaetigers, becoming
two in posterior chaetigers, whereas in S. gingdaoensis there are
always two notopodial capillaries. Finally, the notopodial hooks in
S. magnuncus are much larger than in comparable sized individuals
of the other species.

Growth and abundance

S. magnuncus Was most common in samples from the Porcupine and
Tagus abyssal plains with densities of 4 to 32 individuals per m?,
while lower numbers were found in the Madeira and Cap Verde
samples. This was partly due to lower overall densities of polychaetes
at these latter sites (Paterson et al. 1998), but their distribution
suggests that this species is more common in northern abyssal areas.
Also analysis of the distribution within the sediment suggests that
this species is found within the sediment rather than on the surface.

There is a good range of sizes within the collection, allowing
allometric changes to be noted. Notopodial hooks in smaller speci-
mens appear to be extremely large, but in larger specimens these
hooks are proportionately smaller. This suggests that hooks are
produced at a set size, not affected by growth. The hooks always
occur first on chaetiger 3.

Size of specimens ranges from 0.5 to 10.5 mm, although most

170

individuals were between 0.75 to 4.5 mm long (Fig. 5). The relation-
ship between length of specimen and number of chaetigers is given
in Fig. 4. The graph indicates that initially as individuals increase in
length so the numbers of chaetigers increases linearly, however, at
the upper size there is wide variation in numbers of chaetigers,
suggesting that there may be an upper limit to chaetiger number.

Growth in Sigambra grubii Muller, 1858 also appears to show a
linear relationship between length and number of chaetigers over a
similar size range as S. magnuncus (Salazar-Vallejo, 1990). How-
ever, there was more variation in the relationship between size and
the chaetiger on which the first hook appeared.

ACKNOWLEDGEMENTS. We would like to thank Dr Andrew Mackie (Nat-
ional Museum of Wales) and Alex Muir (NHM) for reviewing the manuscript.
The assistance of the Electron Microscope and Mineral Analysis Division in
the preparation of specimens for the SEM is gratefully acknowledged. The
specimens were collected during a number of oceanographic expeditions and
the authors would like to thank the officers, crew and scientific parties of
Discovery 185, 186, 194, 206 and Challenger 79, 111.We would also like to
thank Dr John Gage, Peter Lamont (Scottish Association for Marine Science),
Dr Brian Bett (Southampton Oceanographic Centre) and Joel Galleron
(CENTOB) for making material available to us. This work was partly
supported by acontract from EU Marine Science and Technology programme
Contract No MAS2-CT920033, which is gratefully acknowledged.

G.L.J. PATERSON AND A.G. GLOVER

REFERENCES

Britaev, T.A. & Saphronova, M.A. 1981. New species of the family Pilargidae
(Polychaeta) from the Sea of Japan and revision of the genus Cabira. Zoologichesky
Zhurnal 60: 1314-1324.

Hartmann-Schroder, G. 1959. Zur Okologie der Polychaeten des Mangrove-Estero-
Gebietes von El Salvador. Beitrdge zur Neotropischen Fauna 1: 69-183.

Licher, F. & Westheide, W. 1994. The Phylogenetic position of the Pilargidae with a
cladistic analysis of the taxon — facts and ideas. In Dauvin, J.C., Laubier L. & Reish
D. J. (Eds) Actes de la 4¢me Conférence internationale dea Polychétes. Mémoires de
la Muséum national d’ Histoire Naturelle 162: 223-235.

Licher, F. & Westheide, W. 1997. Review of the genus Sigambra (Polychaeta:
Hesionidae), redescription of S. bassi (Hartman, 1947), and descriptions of two new
species from Thailand and China. Steenstrupia 23: 1-20.

Paterson, G.L.J., Wilson, G.D., Lamont, P. and Cosson, N. 1998. Hessler and Jumars
revisited. Polychaete assemblages from the abyssal plains of the North Atlantic and
Pacific Oceans. Deep-sea Research I. 48: 225-252.

Pleijel, F. 1998. Phylogeny and classification of Hesionidae (Polychaeta). Zoologica
Scripta 27: 89-163.

Pleijel, F. and Dahlgen, 1998. Position and delineation of Chrysopetalidae and
Hesionidae (Annelida, Polychaeta, Phyllodocida). Cladistics 14: 129-150.

Rice, A.L. , Thurston, M.H. and Bett, B.J. 1994. The IOSDL DEEPSEAS pro-
gramme: introduction and photographic evidence for the presence and absence of a
seasonal input of phytodetritus at contrasting abyssal sites in the northeastern
Atlantic. Deep-Sea Research I 41: 1305-1320.

Salazar-Vallejo, S.I. 1990. Redescription of Sigambra grubii Muller, 1858 and
Hermundura tricuspis Muller, 1858 from Brazil and designation of neotypes
(Polychaeta: Pilargidae). Journal of Natural History 24 507-517.

Bulletin of The Natural History Museum
Zoology Series

Earlier Zoology Bulletins are still in print. The following can be ordered from Intercept (address on inside front cover). Where the complete backlist is not shown,
this may also be obtained from the same address.

Volume 56
No. 1

No. 2

Volume 57
No. 1

No. 2

Volume 58
No. 1

Osteology of the Soay sheep. J. Clutton-Brock, K. Dennis-
Bryan, P. L. Armitage & P. A. Jewell.

A new marine species of Euplotes (Ciliophora, Hypotrichida)
from Antarctica. A. Valbonesi & P. Luporini.

Revision of the genus Eizalia Gerlach, 1957 (Nematoda:
Xyalidae) including three new species from an oil producing
zone in the Gulf of Mexico, with a discussion of the sibling
species problem. D. Castillo-Fernandez & P. J. D.
Lambshead.

Records of Neba/ia (Crustacea: Lepostraca) from the
Southern Hemisphere a critical review. Erik Dahl.

1990. £31.00

Tinogullmia riemanni sp. nov. (Allogromiina: Foraminiferida),
a new species associated with organic detritus in the deep-sea.
A. J. Gooday.

Larval and post-larval development of Anapagurus
chiroacanthus (Lilljeborg, 1855) Anomura: Paguroidea:
Paguridae. R. W. Ingle.

Redescription of Martialia hyadesi Rochebrune and Mabille,
1889 (Mollusca: Cephalopoda) from the Southern Ocean. P.
G. Rodhouse & J. Yeatman.

The phylogenetic relationships of salmonoid fishes. C. P. J.
Sanford.

A review of the Bathygadidae (Teleostei: Gadiformes). G. J.
Howes & O. A. Crimmen. 1990. £36.00

Morphology and biometry of twelve soil testate amoebae
(Protozoa, Rhizopoda) from Australia, Africa and Austria. G.
Liiftenegger & W. Foissner

A revision of Cothurnia (Ciliophora: Peritrichida) and its
morphological relatives. A. Warren & J. Paynter

Indian Ocean echinoderms collected during the Sinbad Voyage
(1980-81): 2. Asteroidea. L. M. Marsh & A. R. G. Price

The identity and taxonomic status of Tilapia arnoldi Bilchrist
and Thompson, 1917 (Teleostei, Cichlidae). P. H. Greenwood
Anatomy, phylogeny and txonomy of the gadoid fish genus
Macruronus Giinther, 1873, with a revised hypothesis of
gadoid phylogeny. G. J. Howes £38.50

The pharyngobranchial organ of mugilid fishes; its structure,
variability, ontogeny, possible function and taxonomic utility.
I. J. Harrison & G. J. Howes

Cranial anatomy and phylogeny of the South-East Asian
catfish genus Belodontichthys. G. J. Howes & A. Fumihito

A collection of seasnakes from Thailand with new records of
Hydrophis belcheri (Gray). C. J. McCarthy & D. A. Warrell
The copepod inhabitants of sponges and algae from Hong
Kong. S. Malt

The freshwater cyclopoid of Nigeria, with an illustrated key to
all species. G. A. Boxshall & E. I. Braide

A new species of Ferdina (Echinodermata: Asteroidea) from
the Sultanate of Oman with discussion of the relationships of
the genus within the family Ophidiasteridae. L. M. Marsh & A.
C. Campbell £38.50

The morphology and phylogeny of the Cerastinae (Pulmonata:
Pupilloidea). P. B. Mordan

No. 2

Volume 59

No. 1

No.

tO

Volume 60

No. |

No. 2

A redescription of the uniquely polychromatic African cichlid
fish Tilapia guinasana Trewavas, 1936. P. H. Greenwood

A revision and redescription of the monotypic cichlid genus
Pharyngochromis (Teleostei, Labroidei). P. H. Greenwood
Description of a new species of Microgale (Insectivora:
Tenrecidae) from eastern Madagascar. P. D. Jenkins

Studies on the deep-sea Protobranchia (Bivalvia): the family
Nuculidae. P. M. Rhind and J. A. Allen £40.30

Notes on the anatomy and classification of ophidiiform fishes
with particular reference to the abyssal genus Acanthonus
Giinther, 1878. G. J. Howes

Morphology and morphogenesis of the soil ciliate Bakuella
edaphoni nov. spec. and revision of the genus Bakuella
Agamaliev & Alekperov, 1976 (Ciliophora, Hypotrichida). W.
Song, N. Wilbert and H. Berger

A new genus and species of freshwater crab from Cameroon,
West Africa (Crustacea, Brachyura, Potamoidea,
Potamonautidae). N. Cumberlidge and P. F. Clark

On the discovery of the male of Mormonilla Giesbrecht, 1891
(Copepoda: Mormonilloida) R. Huys, G. A. Boxshall and R.
Bottger-Schnack £40.30

A new snake from St Lucia, West Indies. G. Underwood
Anatomy of the Melanonidae (Teleostei: Gadiformes), with
comments on its phylogenetic relationships. G. J. Howes

A review of the serranochromine cichlid fish genera
Pharyngochromis, Sargochromis, Serranochromis and Chetia
(Teleostei: Labroidei). P. H. Greenwood

A revision of Danielssenia Boeck and Psammis Sars with the
establishment of two new genera Archisenia and Bathypsammis
(Harpacticoida: Paranannopidae). R. Huys and J. M. Gee.

A new species of Syrticola Willems & Claeys, 1982 (Cope-
poda: Harpacticoida) from Japan with notes on the type
species. R. Huys and S. Ohtsuka

Erratum £40.30

The status of the Persian Gulf sea snake Hydrophis lapemoides
(Gray, 1849) (Serpentes, Hydrophiidae). A. Redsted
Rasmussen.

Taxonomic revision of some Recent agglutinated foraminifera
from the Malay Archipelago, in the Millett Collection, The
Natural History Museum, London. P. Bro6nnimann and J. E.
Whittaker.

Foregut anatomy, feeding mechanisms, relationships and
classification of the Conoidea (=Toxoglossa)(Gastropoda). J. D.
Taylor, Y. I. Kantor and A.V. Sysoey. 1993. Pp. 97-170. £40.30

A new subfamily and genus in Achatinidae (Pulmonata:
Sigmurethra). A. R. Mead.

On Recent species of Spiraserpula Regenhardt, 1961, a
serpulid polychaete genus hitherto known only from Creta-
ceous and Tertiary fossils. T. Gottfried Pillai and H.A. Ten
Hove. 1994. Pp. 1-104. £40.30

Phylogenetic relationships between arietellid genera (Cope-
poda: Calanoida), with the establishment of three new genera.
S. Ohtsuka, G. A. Boxshall and H. S. J. Roe. 1994. Pp. 105—
WW, £40.30

Volume 61
No. 1

No. 2

Volume 62
No. 1

No. 2

Volume 63

No. 1

No. 2

A revised familial classification for certain cirrhitoid genera
(Teleostei, Percoidei Cirrhitoidea), with comments on the
group’s monophyly and taxonomic ranking. P.H. Greenwood.
Studies on the deep-sea Protobranchia (Bivalvia); the Sub-
family Yoldiellinae. J.A. Allen, H.L. Sanders and F. Hannah.
1995. Pp. 1-90. £40.30

Primary studies on a mandibulohyoid ‘ligament’ and other
intrabucal connective tissue linkages in cirrhitid, latrid and
cheilodactylid fishes (Perciformes: Cirrhitoidei). P.H.
Greenwood.

A new species of Crocidura (Insectivora: Soricidae) recovered
from owl pellets in Thailand. P.D. Jenkins and A.L. Smith.
Redescription of Sudanonautes Floweri (De Man, 1901)
(Brachyura: Potamoidea: Potamonautidae) from Nigeria and
Central Africa. N. Cumberlidge.

Association of epaxial musculature with dorsal-fin
pterygiophores in acanthomorph fishes, and its phylogenetic
significance. R.D. Mooi and A.C. Gill. 1995. Pp. 91-138.
£40.30

Deep-sea conolidean gastropods collected by the John Murray
Expedfition, 1933-34. A.V. Sysoev.

Reassessment of ‘Calcinus’ astathes Stebbing 1924 (Crustacea:
Anomura: Paguridea: Diogenidae). P.A. McLaughlin.

On a new species of Ophidiaster (Echinodermata: Asterpodea)
from southern China. Y. Liao and A.M. Clark.

The life cycle of Paracyclops fimbriatus (Fischer, 1853)
(Copepoda, Cyclopoida). S. Karaytug and G.A. Boxshall. 1996.
Pp 1-70. £40.30

Indian Ocean echinoderms collected during the Sindbad Voyage
(1980-81): 3. Ophiuroidea and Echinoidea. A.R.G. Price and
F.W.E. Rowe.

Rare cyclopoid copepods (Crustacea) from Mediterranean
littoral caves. D. Jaume and G.A. Boxshall.

Studies on the deep-sea Protobranchia (Bivalvia): the family
Neilonellidae and the family Nuculanidae. J.A. Allen and

H.L. Sanders. 1996. Pp 71-132. £40.30

A new species of Microgale (Insectivora: Tenrecidae), with
comments on the status of four other taxa of shrew tenrecs.
P.D. Jenkins, C.J. Raxworthy and R.A. Nussbaum.

Notes on the anatomy and relationships of Sundasalanx
Roberts (Teleostei, Clupeidae), with descriptions of four new
species from Borneo. D.J. Siebert.

Redescription of and lectotype designation for Balistes
macropepsis Boulenger, 1887, a senior synonym of
Canthidermis longirostris Tortonese, 1954 and C. villosus
Fedoryako, 1979 (Teleostei, Tetraodontiformes, Balistidae).
A.C. Gill and J.E. Randall.

A new species of crassispirine gastropod from the Houtman
Abrolhos islands, Western Australia (Gastropoda, Conoidea,
Crassispirinae). A.V. Sysoev and J.D. Taylor.

Foregut anatomy and relationships of the Crassispirinae
(Gastropoda, Conoidea). Y.I. Kantor, A. Medinskaya and
J.D. Taylor. 1997. Pp 1-92. £40.30

The lucinid bivalve genus Cardiolucina (Mollusc: Bivalvia:
Lucinidae); systematics, anatomy and relationships. J.D. Taylor
and E.A. Glover.

A new species of water mouse, of the genus Chibchanomys
(Rodentia: Muridae: Sigmondontinae) from Ecuador. P.D.
Jenkins and A.A. Barnett.

Volume 64

No. |

No. 2

Volume 65

No. 1

No. 2

Volume 66

No. 1

A new species in the asterinid genus Patiriella (Echinodermata:
Asteroidea) from Dhofar, southern Oman: a temperate taxon in
a tropical locality. A.C. Campbell and F.W.E. Rowe.
Morphological observations on Oncaea mediterranea (Claus,
1863) (Copepoda: Poecilostomatoida) with a comparison of
Red Sea and eastern Mediterranean populations. R. B6ttger-
Schnack and R. Huys. 1997. Pp. 93-147. £40.30

A revision of the cladoceran genus Simocephalus (Crustacea,
Daphniidae). Marina J. Orlova-Bienkowskaja.

Structural niche, limb morphology and locomotion in lacertid
lizards (Squamata, Lacertidae); a preliminary survey.

E.N. Armold.

Hetereleotris georgegilli, a new species of gobiid fish, with
notes on other Mauritian Hetereleotris species. Anthony C. Gill
Revision of Schismatorhynchos Bleeker, 1855 (Teleostei,
Cyprinidae), with the description of two new species from
Borneo. Darrell J. Siebert and Agus H. Tjakrawidjaja. 1998.
Pp. 1-109. £40.30

Partial revision of Paracyclops Claus, 1893 (Copepoda,
Cyclopoida, Cyclopidae) with descriptions of four new species.
S. Karaytug and G.A. Boxhall.

First records and a new subspecies of Rhinolophus stheno
(Chiroptera, Rhinolophidae) from Vietnam. G. Csorba and P.
Jenkins. 1998. Pp. 111-211. £40.30

Phylogenetic relationships of Toad-headed lizards
(Phrynocephalus, Agamidae) based on morphology.

E.N. Arnold.

Rita sacerdotum, a valid species of catfish from Myanmar
(Pisces, Bagridae). C.J. Ferraris, Jr.

Indian Ocean echinoderms collected during the Sinbad Voyage
(1980-81): 4. Crinoidea. J.I.M. Crossland and A.R.G. Price.
On the hybrid status of Rothschild’s Parakeet Psittacula
intermedia (Aves, Psittacidae). P.-C. Rasmussen and N.J. Collar.
A review of the genus Bargamannia Totton, 1954
(Siphonophorae, Physonecta, Pyrostephidae). P.R. Pugh. 1999.
Pp. 1-72. £40.30

Systematics and phylogeny of Zausodes C.B. Wilson, 1932
(Copepoda, Harpacticoida, Harpacticidae), including three new
species from the northern Gulf of Mexico. L. Bouck, D. Thistle
and R. Huys.
Nybelinia southwelli sp. nov. (Cestoda, Trypanorhyncha) with
the re-description of N. perideraeus (Shipley & Hornell, 1906)
and the synonymy of N. herdmani (Shipley & Hornell, 1906)
with Kotorella pronosoma (Stossich, 1901). H.W. Palm and T.
Walter.
Nybelinia Poche, 1926, Heteronybelinia gen. noy. and
Mixonybelinia gen. nov. (Cestoda, Trypanorhyncha) The
Natural History Museum, London. H.W. Palm.
A new species of Microgale (Lipotyphla, Tenrecidae) from
isolated forest in southwestern Madagascar. P.D. Jenkins and
S.M. Goodman.
Modes of ear reduction in iguanian lizards (Reptilia, [guania);
different paths to similar ends. E.N. Arnold. 1999. Pp. 73-171.
£40.30

Generic concepts in the Clymnestridae (Copepoda,
Harpacticoida): revision and revival. R. Huys and S. Conroy-
Dalton.

Basal resolution of laophontid phylogeny and the paraphyly of
Esola Edwards. R. Huys and W. Lee. 2000. Pp. 1-107. £40.30

GUIDE POR AUTHORS

Aims and scope. The Bulletin of the British Museum (Natural
History) Zoology, was established specifically to accommodate
manuscripts relevant to the Collections in the Department of Zool-
ogy. It provides an outlet for the publication of taxonomic papers
which, because of their length, prove difficult to publish elsewhere.
Preference is given to original contributions in English whose
contents are based on the Collections, or the description of speci-
mens which are being donated to enhance them. Acceptance of
manuscripts is at the discretion of the Editor, on the understanding
that they have not been submitted or published elsewhere and
become the copyright of the Trustees of the Natural History Mu-
seum. All submissions will be reviewed by at least two referees.

Submission of manuscripts. Initially three clear, complete cop-
ies should be submitted in the style and format of the Bulletin. The
text must be typed double-spaced throughout, including references,
tables and legends to figures, on one side of A4 paper with 2.5 cm
margins. All pages should be numbered consecutively, beginning
with the title page as p. 1. Sl units should be used where appropriate.

Whenever possible a copy of the text, once the paper has been
accepted, should also be provided on floppy disc (see below). Discs
should only be sent after final acceptance, as papers generally need
revision after refereeing. If it is impossible to provide an appropriate
disc please ensure that the final typescript is clearly printed.

Authors are requested to ensure that their manuscripts are in final
format, because corrections at proof stage may be charged to the
author. Additions at proof stage will not normally be allowed. Page
proofs only will be sent.

Word-processor discs. _ Please follow these instructions.

1. Ensure that the disc you send contains only the final version of
the paper and is identical to the typescript.

2. Label the disc with the author’s name, title of the paper and
the word-processor programme used. Indicate whether IBM or
Apple Mac (IBM preferred).

3. Supply the file in the word-processor format; if there is a
facility to save in ASCII please submit the file in ASCII as well.

4. Specify any unusual non-keyboard characters on the front
page of the hard copy.

5. Do not right-justify the text.

6. Do not set a left-hand margin.

7. Make sure you distinguish numerals from letters, e.g. zero (0)
from O; one (1) from | (el) and I.

8. Distinguish hyphen, en rule (longer than a hyphen, used
without a space at each end to signify ‘and’ or ‘to’, e.g. the Harrison—
Nelson technique, 91-95%, and increasingly used with a space at
each end parenthetically), and em rule (longer than an en rule, used
with a space at each end parenthetically) by: hyphen, two hyphens
and three hyphens, respectively. Be consistent with rule used paren-
thetically.

9. Use two carriage returns to indicate beginnings of paragraphs.

10. Be consistent with the presentation of each grade of heading
(see Text below).

Title. The title page should be arranged with the full title; name(s)
of author(s) without academic titles; institutional address(es); sug-
gested running title; address for correspondence.

Synopsis. Each paper should have an abstract not exceeding 200
words. This should summarise the main results and conclusions of
the study, together with such other information to make it suitable
for publication in abstracting journals without change. References
must not be included in the abstract.

Text. All papers should have an Introduction, Acknowledge-
ments (where applicable) and References; Materials and Methods
should be included unless inappropriate. Other major headings are
left to the author’s discretion and the requirements of the paper,
subject to the Editors’ approval. Three levels of text headings and

sub-headings should be followed. All should be ranged left and be in
upper and lower case. Supra-generic systematic headings only
should be in capitals; generic and specific names are to be in italics,
underlined. Authorities for species names should be cited only in the
first instance. Footnotes should be avoided if at all possible.

References. References should be listed alphabetically. Authori-
ties for species names should not be included under References,
unless clarification is relevant. The author’s name, in bold and lower
case except for the initial letter, should immediately be followed by
the date after a single space. Where an author is listed more than
once, the second and subsequent entries should be denoted by a long
dash. These entries should be in date order. Joint authorship papers
follow the entries for the first author and an ‘&’ should be used
instead of ‘and’ to connect joint authors. Journal titles should be
entered in full. Examples: (i) Journals: England, K.W. 1987. Certain
Actinaria (Cnidaria, Anthozoa) from the Red Sea and tropical Indo-
Pacific Ocean. Bulletin of the British Museum (Natural History),
Zoology 53: 206-292. (ii) Books: Jeon, K.W. 1973. The Biology of
Amoeba. 628 p. Academic Press, New York & London. (iii) Articles
from books: Hartman, W.D. 1981. Form and distribution of silica in
sponges. pp. 453-493. In: Simpson, T.L. & Volcani, B.E. (eds)
Silicon and Siliceous Structures in Biological Systems. Springer-
Verlag, New York.

Tables. Each table should be typed on a separate sheet designed to
extend across a single or double column width of a Journal page. It
should have a brief specific title, be self-explanatory and be supple-
mentary to the text. Limited space in the Journal means that only
modest listing of primary data may be accepted. Lengthy material,
such as non-essential locality lists, tables of measurements or details
of mathematical derivations should be deposited in the Biological
Data Collection of the Department of Library Services, The Natural
History Museum, and reference should be made to them in the text.

Illustrations

DRAWINGS — Figures should be designed to go across single (84 mm
wide) or double (174 mm wide) column width-of the Journal page,
type area 235 x 174 mm. Drawings should be in black on white stiff
card with a line weight and lettering suitable for the same reduction
throughout, ideally not more than 40%. After reduction the smallest
lettering should be not less than 10 pt (3 mm). Tracing paper should
ideally be avoided because of the possibility of shadows when
scanned. All artwork must have bulletin, author and figure number
included, outside of the image area, and must be free of pencil, glue
or tape marks.

PHOTOGRAPHS — All photographs should be prepared to the final size
of reproduction, mounted upon stiff card and labelled with press-on
lettering (eg Letraset). They can be mounted on white or black
background; a black background must be evenly black all over; any
background must be free of all pencil and glue marks within the
image area. All figures should be numbered consecutively as a
single series. Legends, brief and precise, must indicate scale and
explain symbols and letters. Photos, when components of figure-
plates should be abutted, trimmed as regular rectangles or close
trimmed up to edge of specimen. Joins etc. can be removed at the
scanning stage but at extra cost. Cropping instructions, if any, should
be indicated on an overlay or marked on a photocopy of the figure.
SIZE — Maximum size of artwork for use of flatbed scanners is A3.
Larger artwork has to be reduced photographically prior to scan-
ning, therefore adding to expense.

Symbols in text. Male and female symbols within the text should
be flagged within curly brackets to enable setter to do a swift global
search.

Reprints. 25 reprints will be provided free of charge per paper.
Orders for additional reprints can be submitted to the publisher on
the form provided with the proofs. Later orders cannot be accepted.

CONTENTS

109 The shallow-water marine Mollusca of the Estero Elefantes and Laguna San Rafael,
southern Chile
D.G. Reid and C. Osorio

147 Remarks on the genera Schizocuma Bacescu, 1972 and Styloptocuma Bacescu & Muradian,
1974 (Crustacea, Cumacea)
|. Petrescu

167 Anew species of Sigambra (Polychaeta, Pilargidae) from the abyssal plains of the NE
Atlantic
G.L.J. Paterson and A.G. Glover

Bulletin of The Natural History Museum

ZOOLOGY SERIES
Vol. 66, No. 2, November 2000