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IE WESTERN SOCIETY
OF MALACOLOGISTS
Annual Report
Volume 38
field museum
library
JUL 12 2017
RECEIVED
Abstracts and Papers from the
38th Annual Meeting of the Western Society of Malacologists
Held in Association with the 71st Meeting of the American Malacological Society
Asilomar, California
June 26-30, 2005
Published May 2010
Western Society of Malacologists
Officers 2005-2006
President
First Vice President (2007 President)
Third Vice President (2008 President)
Secretary
Treasurer
Committees
Editorial Board for Volume 38
Peter Roopnarine
Roland Anderson
Charles Powell, II
Steve Lonhart
Steve Lonhart
Hans Bertsch
Nora Foster
Charles Powell, II
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 1
Contents
iL
Abstracts and Papers from the 38 Western Society of Malacologists Meeting
Phytogeny and Biogeography of the Atlantic and Eastern Pacific Hypselodoris
Stimpson, 1855 (Nudibranchia, Chromodorididae), with the Description of a New
Species from the Caribbean Sea
t r
Alvin Alejandrino and Angel Valdes 12
A Unique Deep-Water Molluscan Ecosystem from the Northwestern Slope of the
Great Bahama Bank
William C. Aley, IV 12
Detecting and Interpreting Morphologic Constraint in the Fossil Record
Laurie C. Anderson, Audrey Aronowsky, and Peter D. Roopnarine 13
Results of the Giant Pacific Octopus Census in Puget Sound, 2000-2005
Roland C. Anderson 13
The Packaging Problem: Bivalve Prey Selection and Prey Entry Techniques of
Enteroctopus dofleini (Cephalopoda: Octopodidae)
Roland C. Anderson and Jennifer A. Mather 14
Monospecific Fossil Assemblages: Distinguishing between Accumulation and
Aggregation Using Phylogeny and Paleobiology
Audrey Aronowsky and Laurie C. Anderson 14
Extinction and the Life History of Unionid Bivalves
Chris Barnhart 15
Gametogenesis and Fecundity of Atrina maura in Laguna de San Ignacio,
Baja California Sur, Mexico
Daniela Barrios Ruiz and Carlos Caceres Martinez 16
Reproductive effort of Atrina maura in Laguna San Ignacio, Baja
California Sur, Mexico
Daniela Barrios Ruiz and Carlos Caceres Martinez 16
Morphological and Behavioral Defenses in Three Species of Whelks in the Genus
Nucella
Paul E. Bourdeau 17
Molecular Systematics of Problematic Unionids
David C. Campbell 17
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 2
Mollusean Faunas and Zoogeography of the Georgia Neogene
Lyle D. Campbell and Sarah C. Campbell 18
Systematics and Phylogenetics of the Family Streptacididae (Gastropoda:
Heterobranchia) from Devonian through Triassic Marine Strata
Matthew R. Campbell 19
My sella pedroana , Not Another Host-Specific Bivalve
Shannon M. Carpenter 19
Reevaluating the Facelinidae: Systematics and Phylogeny
Jamie M. Chan and Terrence M. Gosliner 20
A Preliminary Study of the Biology of Veronicella sloanei (euvier, 1817) in Barbados
Nickelia Clarke and H. Angela Fields 20
Partula : the Birth and Death of Species
Bryan Clarke and James Murray 2 1
Molecular Insights into Biogeographic Patterns of Speciation in Marine Molluscs
Rachel Collin 21
Partulids on Tahiti: an Interesting Distribution among Surviving Populations
Trevor Coote and Walter Teamotuaitau 22
Morphological Variation in Allopatric Populations of Acanihina and Nerila Gastropods
in the Northern Gulf of California
Raena Cota, Allison Gilliland, Shannon O’Hara, Urs Riner, Michael Lorentzen,
Ryan Horenziak, Emerald Tataryn and Stephen Shuster 22
Persistence of a Native Brackish- Water Hydrobiid Snail Population in Certain Restored
Marshes of Southern Suisun Bay, San Francisco Estuary
Cheryl L. Davis and Christopher L. Kitting 23
Predation by Euglandina rosea on Local Versus Non-local Gastropods: No Differences in
Mucus Trail Following?
Elizabeth C. Davis 23
A Survey of Aquatic and Terrestrial Gastropods in Kansas: the Nature Conservancy’s
Welda Prairie and the Fitch Natural History Reservation
Elizabeth C. Davis 24
Sex and Darts in Slugs and Snails
Angus Davison 24
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 3
Needs and Predictions for 21st Century Molluscan Alpha-Taxonomy
Benoit Dayrat 25
Empirical Estimates of Reproductive Isolation among the Freshwater Pulmonate
Snails Physa acuta , P. pomilia and P. hendersoni
Robert T. Dillon, Jr., John D. Robinson and Amy R. Wethington 25
Phylogeny and Comparative Phylogeography of West Coast Chitons
Douglas J. Eemisse and Ryan P. Kelly 26
Evolution of Poecilogony from Planktotrophy: Speciation in the Sea Slug Genus Alderia
Ryan A. Ellingson and Patrick J. Krug 27
Phylogeography and Genetic Population Structure of Vermetids in Ilawai’i
Anuschka Faucci 27
Preliminary Report of the Terrestrial Molluscan Fauna of the Eastern Caribbean
Islands, and Trinidad & Tobago
H. Angela Fields and David G. Robinson 28
Endemism, Introduced Species and Conservation in the Austral Islands
(French Polynesia)
Benoit Fontaine and Olivier Gargominy 28
Ametamorphic Direct Development in Dendrodoris behrensi (Nudibranchia:
Dendrodorididae) from the Northeast Pacific Ocean, with a Review of Developmental
Mode in the Family
Jeffrey H. R. Goddard 29
You can Teach Old Clams New Tricks: Reconstructing Patterns and Timing of
Growth - Methods and Applications
David H. Goodwin 30
Systematics and Phylogeny of Babakina (Nudibranchia: Aeolidoidea)
Terrence M. Gosliner, Manuel M. Gonzalez-Duarte and Juan Lucas Cervera 30
Mating Systems and Family Conflicts in a Marine Snail
Rick Grosberg 3 1
*
Explaining Generic Endemism in the Pacific Coast Tertiary Molluscan Faunas
David Haasl, Jann E. Vendetti, and Carole S. Hickman 32
Progress in the Conservation of Hawaiian Achatinelline Snails
Michael G. Hadfield 32
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 4
Larval Settlement in Response to Soluble Cues from the Benthos
Michael G. Hadfield and Mimi A. R. Koehl 33
Preliminary Phylogenetic Assessment of Invasive Apple Snails in Asia and Beyond
Kenneth A. Hayes 33
Hybridization: Lofty Theories, Taxonomic Reality
Joseph Heller 34
Geologic and Evolutionary Context of Land Snail Diversity on Oceanic Islands
Carole S. Hickman 34
Larval Dispersal and Modes of Speciation: Hypothesis Testing in Littorina
Dmil A LI /\L 1 rvL /%
i aui rS l. nuii^nionc
Evolutionary Patterns in Pacific Amber Snails (Succineidae): the Relative Roles
of Vicariance and Dispersal in Diversification and Island Biogeography
Brenden S. Holland and Robert H. Cowie 36
What Can “Stems, Loops and Lollipops” Tell Us About Basommatophora?
Wallace Holznagel 36
Historic Pacific Grove Intertidal Nudibranch Collections are a Baseline with
Which to Test Climate-related Species Range Change Hypotheses
Rebecca F. Johnson 37
Historical Phylogeny of Tahitian Partula
Younghun Jung, Taehwan Lee, John B. Burch and Diarmaid O Foighil 37
Species-level Phylogeny and Phylogeography of Conus', a Progress Report
Alan J. Kohn, Christopher P. Meyer and Thomas F. Duda, Jr. 38
Frustrated Virgins and Reproductive Flexibility in the Sacoglossan Sea Slug
Alderia: How Hypodermic Insemination Affects Selling and Speciation
Patrick J. Krug 39
Mediterranean Land Snails and Wildfires
Esther Lachman 39
Predator-prey Dynamics of Late Paleozoic Ecosystems: a Case-study on the
Role of Molluscs
Lindsey R. Leighton and Jennifer A. Sawyer 40
Sexual Selection and Mating Systems in the Genus Ariolimax
(Stylommatophora: Gastropoda)
Janet L. Leonard, Jane A. Westfall and John S. Pearse 41
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 5
Hemocyanin and Molluscan Phytogeny: Outcomes, Restrictions, and Perspectives
Bernhard Lieb and Jurgen Markl 4 1
A Combined Analysis of the Phylogeny of Cephalopoda
Annie Lindgren and Frank Anderson 42
Extinction and the Evolutionary History of Late Cretaceous and Early Cenozoic
Veneroid Bivalves
Rowan Lockwood 42
Dichostasiidae Yochelson, 1956, Permian to Holocene, Defined on Opercular and
Shell Characters (Vetigastropoda: Trochoidea)
James H. McLean 43
Elemental Fingerprinting to Determine Larval Dispersal: an Example Using
Mytilid Mussels
Pat A. McMillan, L. A. Levin, B. J. Becker, F. J. Fodrie and L. Rasmussen 44
Evolution of Anatomy and Morphology in Miniaturized Marine Snails
(Neogastropoda: Columbellidae)
Marta J. deMaintenon 45
Do More Tissues Automatically Equate to a Heavier Breather?
Claire-Louise Martin 45
Changes in the Mussel Community of Ohio Brush Creek
Stephen F. Matter, Francisco J. Borrero and Chris Bedel 46
Mating and Egg-laying Behavior in Aplysia : Pheromones and Neural Mechanisms
Earl Mayeri 46
Interpreting Life’s History Through the Lens of the Present: Accounting for
Variability in Biogeographic Inference
Christopher P. Meyer 47
Mexican Holospirinae in Review (Gastropoda: Urocoptidae)
Elizabeth L. Mihalcik and F. G. Thompson 47
Two New Northeastern Pacific Nudibranchs
Sandra Millen 48
Pondering the Purpose of Precarious Postures: the Effect of Littorine Snail Shell
Orientation on Body Temperature
Luke P. Miller 48
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 6
Sexual Conflict and the Rise of Alternative Reproductive Tactics in the Banana slug,
Ariolimax dolichophallus
Brooke L.W. Miller 49
Quantitative and Qualitative Variation of the Protein Content of the Embryos of
Crepidula navicula (Caenogastropoda: Calyptraeidae) During Intracapsular
Development
Patricia Miloslavich and Elizabeth Huck 49
Mapping Marine Invertebrate Biodiversity Hotspots in the Indo-Pacific
Ocean Using GIS
Fabio Moretzsohn and Myra K.K. McShane 50
Biodiversity of Marine Molluscs of the Gulf of Mexico
Fabio Moretzsohn and John W. Tunnell, Jr. 5 1
Identification of Host Specific Genes in a Sepiolid Squid I Vibrio Mutualism
Michele K. Nishiguchi 5 1
Using Nested Clade Analyses for Determining Species Boundaries in Three
Indo-west Pacific Euprymna Species and Their Luminescent Symbionts
Michele K. Nishiguchi 52
A New Species of Sinezona from the Canary Islands (Gastropoda: Vetigastropoda:
Scissurellidae)
Jaya Nolt 52
Revised Generic Placement of Transenella humilis to Nutricola
Jaya Nolt 53
Gametogenesis and Size at Reproductive Maturity of Melongena melongena
(Linnaeus, 1758) (Caenogastropoda: Melongenidae) at Golfete de Cuare, Venezuela
Nicida Noriega and Patricia Miloslavich 53
The Relationship Between Body Size, Growth, and Egg Production in the
Hermaphroditic Freshwater Snail, Helisoma trivolvis
Cynthia G. Norton and Jennifer M. Bronson 54
The Diversification of the Family Enidae in Turkey: an Evolutionary Perspective
Aydin Orstan and M. Zeki Yildirim 54
Phenotypic Plasticity in Molluscs
Dianna K. Padilla 55
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 7
Identifying the Pupilloids Gastrocopta peniodon and G. tappaniana on the Delmarva
Peninsula, Eastern USA
Timothy A. Pearce 55
A Summary of the International Partulid Conservation Programme and its
Significance for Other Group-level Managed Species
Paul Pearce-Kelly 56
Phylogeography of Banana Slugs (. Ariolimax spp.) (Gastropoda: Stylommatophora:
Arionidae)
J.S. Pearse, K. Breugelmans, T. Backeljau and J.L. Leonard 56
A Phylogenetic Study of the Invasive Land Snail Species Praticolella griseola
(Gastropoda: Polygyridae)
Kathryn E. Perez 57
Determinate Growth and Variable Size at Maturity in the Marine Gastropod
Amphissa columbiana (Columbellidae)
Bruno Pemet 57
Detection of alternative stable states in extant communities: the need for a historical
perspective
Peter S. Petraitis 58
A Preliminary Review of California Fossi \ Austrotrophon and Forreria (Gastropoda:
Muricidae: Ocenebrinae)
Charles L. Powell, II 58
Temporal Community Structure and Biodiversity of Malacofauna from an
Urban New Jersey Pond
Robert S. Prezant and Eric J. Chapman 59
Mating and Reproduction in Deroceras Slugs
Heike Reise 59
Steps Towards a Revision of Hemphillia Jumping Slugs
Heike Reise and John M.C. Hutchinson 60
Mollusk Survey and Basic Ecological Studies in Hells Canyon, Snake River, USA
David C. Richards, C. Michael Falter, Gary T. Lester and Ralph Myers 60
Discovery of Copulatory Structures in Male Helicinidae (Gastropoda: Neritopsina:
Helicinidae)
IraRichling 61
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 8
Cheklist of Gastropods and Bivalves from the Coasts of Chiapas and Oaxaca, Mexico
Eduardo Rios-Jara, Ceciel Navarro-Caravantes, Martin Perez Pena, Ernesto Lopez
Uriarte and Ildefonso Enciso Padilla 62
Report on the Current Status of Introduced Species of Achatinidae and Other
Economically Snail and Slug Pests in the Eastern Caribbean
David G. Robinson and H. Angela Fields 62
Report on the Spread of the Cuban Slug Veronicella cubensis (Pfeiffer, 1840) in Guam
and Rota in the Northern Mariana Islands, and the Loss of Molluscan Biodiversity
Apparently Resulting from Introduced Invasive Gastropod Species and the Triclad
Flatworm Platydemus manokwari de Beauchamp, 1963
David G. Robinson and Robert G. Hollingsworth 63
Comparative Phylogeography of Chitons and Limpets in Southern California
Albert Rodriguez, Ryan P. Kelly and Douglas J. Eemisse 64
Taxonomic Revision of Endemic Nicaraguan Freshwater Mussels
(Bivalvia: Unionidae)
Kevin J. Roe and Adolfo Lopez de la Fuente 64
Developmental and Phenotypic Integration in Bivalves: Adaptation and Evolution of
the Neogene Venerid Genus Chione
Peter D. Roopnarine, Kenneth Angielczyk, Viviane Callier and
Laurie C. Anderson 65
Evolution of the Palau Diplommatinids and Conservation of the Land Snails of Palau
and the Southwest Islands
Rebecca J. Rundell 66
The Evolution of Exoskeleton Nucleation in Shelled Fossils and Holocene Molluscs
Amelie H. Scheltema 66
Understanding the Evolution and Development of Pallial Eyes in the Pectinidae
Jeanne M. Serb 67
Fiat Oysters Show Evidence for Allopatric Speciation, Ecological Transition and
Introgression Among Developmentally Heterogeneous Taxa
Meghan H. Shilts 67
Diversity of Terrestrial Snails on the Three Largest Islands in the Louisiade
Archipelago, Papua New Guinea
John Slapcinsky 68
A Re-description of Marionia rubra (Ruppell and Leuckart, 1831)
Victor G. Smith and Terrence M. Gosliner 69
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 9
Stable Isotope Growth Profiles of Holocene and Cenozoic Mollusks
Josiah Strauss and Anton Oleinik 69
Differential Expression of Vetigastropod Hemocyanin
Klaus Streit and Bernhard Lieb 70
New Morphological Data for Pleuroceridae (Gastropoda: Cerithioidea): Implications
for Monophyly and Affinity of the Family
Ellen E. Strong 70
Reproductive Behavior of the Dioecious Tidal Snail, Cerithidea rhizophorarum
(Gastropoda: Patamididae)
Maya Takeuchi, Karurm Ohtaki and Kiyonon Tomiyama
n i
/ 1
Detecting Stability and Change in Fossil Communities: the Need for Temporal- and
Scale-dependent Perspectives
Carol M. Tang 72
The Year of the Pond Snail
Andries Ter Maat, Cora Montagne-Wajer and Joris M. Koene 72
Missing Pieces in the Speciation Puzzle: an Example of the Palaeontogical Imperative
in Interpreting Biogeographic Patterns in a Neotropical Marine Gastropod Radiation
Jonathan A. Todd 73
Biomineralization in the Radula of the Aplacophoran Mollusk Helicoradomenia
(Solenogastres)
Christiane Todt 73
Impacts of Urbanization on the Biodiversity of the Imperiled Snail Fauna (Gastropoda:
Prosobranchia: Pleuroceridae) of the Cahaba River, Alabama, USA
Lori Tolley-Jordan 74
Inducible Defense in a Marine Snail: Cue Sensitivity and the Scaling of Trade-offs
Geoffrey C. Trussed 75
Texas Seashells: a New Illustrated Guide
J.W. Tunnell, Jr., N.C. Barrera, R. Davenport, D. Hicks and J. Andrews 75
Crossing the Pond: Dorid Nudibranch Strategies for Transatlantic Dispersal
Angel Valdes and Alvin Alejandrino 76
Unexpected Diversity Recovered with Experimental Wood Deployments in the Deep
North Pacific Ocean
Janet R. Voight 76
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 10
Taxonomic Distribution and Phylogenetic Utility of Gender-associated Mitochondrial
Genomes in the Unionoida (Bivalvia)
Jennifer M. Walker, Jason P. Curole, Arthur E. Bogan, G. Thomas Watters and
Walter R. Hoeh 77
Examination of Lineage Diversity and Isolation of Oreohelix strigosa cooperi ,
Black Hills, South Dakota
Kathleen Weaver, Tamara Anderson and Robert Guralnick 77
Genetic Structure of Biomphalaria glabrata Populations Sampled from a
Schistosomiasis Endemic Region
A.R. Wethington, M.K. Smith, G. Oliveira, F. Lewis and D.J. Minchella 78
Phylogenetics of the Genus Isognomon (Bivalvia: Pterioidea): Initial Findings and
Cross-isthmus Invasions
John A. Wilk 79
Morphology and Function of Invertebrate Hemocytes: Physiological Effects of
Stress in Aplysia calif ornica
Heather R. Wilkinson and Gary G. Martin 79
A PCR-based Method for Identifying Individual Larvae of Molluscs
Demian A. Willette and Patrick J. Krug 80
Genetics of Sex Ratio Variation in the Apple Snail, Pomacea canaliculata
Yoichi Yusa 80
The Genus Thyasira Leach, 1817 (Lucinoidea: Thyasiridae), in the Magellan Region
and Adjacent Antarctic Waters
Diego G. Zelaya 81
The Diversity of Scissurellidae and Anatomidae in Sub-Antarctic and Antarctic
Waters: Preliminary Results
Diego G. Zelaya and Daniel L. Geiger 81
Federal Efforts to Exclude Snails and Slugs Associated with Agricultural Imports
Frederick J. Zimmerman 82
Contributed Paper
XI Reunion de la Asociacion Nacional De Malacologia y Conquiliologia (XI RENAMAC):
a Report on the August 2009 Meeting
Hans Bertsch and Esteban Felix Pico 83
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 1 1
Phylogeny and Biogeography of the Atlantic and Eastern Pacific Hypselodoris
Stimpson, 1855 (Nudibranchia, Chromodorididae), with the
Description of a New Species from the Caribbean Sea
Alvin Alejandrino and Angel Valdes
Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007
sounion75@hotmail.com
A new species, based on two specimens collected from Guana Island, British Virgin
Islands is described. The new species agrees with the genus Hypselodoris in having a high body
profile, a large vestibular gland, and mantle glands. The new species externally differs from
other members of the genus in the Atlantic Ocean by having a reddish background body color.
In addition, dorsal color patterns such as a broad central white line with lateral extensions and
the lack of yellow lines or spots further differentiate this species. Internally, the radular fonnula
of 52 x 41.0.41 and a smaller seminal receptacle offer distinctive features for this species. The
phylogenetic relationships of 34 species and subspecies of Hypselodoris from the eastern Pacific
and Atlantic are examined using morphological characters. With the exception of the new
species, all these species are characterized by having a dark blue background body color. The
phylogenetic analysis of the data matrix resulted in eight most-parsimonious trees. The resulting
consensus tree shows that eastern Pacific and Atlantic species of Hypselodoris constitute a
monophyletic group, which is basally split into two sister clades. One clade contains the eastern
Pacific species and most of the Caribbean species, whereas the other clade contains the eastern
Atlantic species. The new species is sister to the rest of the Caribbean species, which are also a
monophyletic group.
A Unique Deep-Water Molluscan Ecosystem from the Northwestern Slope of
the Great Bahama Bank
William C. Aley, IV
Department of Geosciences, Florida Atlantic University, Boca Raton, Florida, 3343 1 ; walev@fau.edu
Three successive deep water surveys of the northwestern margin of the Great Bahama
Bank, in the vicinity of Victory Cay (Bimini chain) were conducted during years 2001, 2002, and
2003 from fne Florida Institute of Oceanography (FIO) research vessels “Bellows” and
“Suncoaster.” The surveys were conducted using a fixed frame 1.0’ x 3.0’ Cape Town dredge at
depths of 200-600 meters. Eighty- one species of mollusks belonging to 40 families have been
collected and identified, many of which are rare or endemic to the Bimini Islands vicinity.
Dredged material consisted of two main components: (1) dead and eroded remains and complete
shells of shallow water mollusks that resulted from post-mortem transportation down the steep
slope of the Bahama Platform and (2) live deep sea mollusks inhabiting a unique slope
ecosystem. The dominant species of this relatively unknown ecosystem are: Conus (Lindaconus)
lindae (Petuch, 1987), Tugurium caribaeum (Petit, 1856) and a new species of Scaphella cf. S.
gaudiati Bail et Shelton, 2001. A number of factors are found to control the existence of this
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 12
unique assemblage including, but not limited to, the distinctive slope topography of the
northwestern margin of the Bahama Bank, and a Gulf Stream tunneling effect which alters
current structure and velocity at this narrowest portion of the Florida Strait causing an
asymmetrical water temperature profile from west to east across the Strait of Florida.
Detecting and Interpreting Morphologic Constraint in the Fossil Record
1 9 o
Laurie C. Anderson , Audrey Aronowsky and Peter D. Roopnarine
'Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803
laurie@geol.lsu.edu
2Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803
department of Invertebrate Zoology & Geology, California Academy of Sciences,
55 Music Concourse Dr., San Francisco CA 94118
At all taxonomic levels, from Bauplane to morphospecies, morphologic variation is
neither randomly nor evenly distributed. This pattern is the product of adaptation, constraint, and
plasticity acting on populations in ecological time and on lineages in evolutionary time. Because
lineages can maintain their morphologic identity over millions of years and numerous speciation
and extinction events, constraint is critical to macroevolution.
The Corbulidae (Bivalvia) is a morphologically diverse clade containing several
morphologically conservative subclades that provide an opportunity to examine the role of
constraint in evolutionary history. For the Caryocorbula + ( Bothrocorbula + Hexacorbula )
clade, all from Caribbean Neogene deposits, each genus is morphologically distinct both in shape
and size. In addition, Caryocorbula morphospecies exhibit strong interspecific allometry that
persists despite repeated speciation and extinction, as well as the vagaries of geographic and
temporal sample coverage. In spite of the conservative morphology within this basal clade, more
derived corbulid clades subsequently occupied new areas of morphospace.
Paleontologic data allow morphology to be examined in a geographic by temporal matrix
over evolutionary time scales. For extinct taxa, whose diversity far exceeds that of extant
members in many molluscan clades, the fossil record is the only source of information on
evolutionary patterns. Thus, although it is often not possible to identify causes of morphologic
constraint (e.g., pleiotropy vs. stabilizing selection), the fossil record provides the opportunity to
examine morphologic response to changing environmental conditions over evolutionary time
both within and among species.
Results of the Giant Pacific Octopus Census in Puget Sound, 2000-2005
Roland C. Anderson
The Seattle Aquarium, 1483 Alaskan Way, Seattle, WA 98101
A scuba diving survey was organized on 19 February 2000 by the Seattle Aquarium in
Puget Sound (Washington State, USA) to establish a baseline of how many giant Pacific
octopuses (Enteroctopus dofleini) there were in the area and to determine if the population was
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 13
healthy. Information requested from the volunteer divers was location, depth, time, description of
dens, and an estimate of size. There were 18 octopuses spotted that day by 1 14 divers looking at
19 popular dive sites where octopuses had been seen historically. Four octopuses were females
guarding eggs. Since then, the census was increased to the three days over a holiday weekend
with increased participation and increased octopus sightings. In 2005, 210 divers reported seeing
61 octopuses, none in southern Hood Canal. Implications of the results of this census in relation
to behavior, life history, and biology of these octopuses, environmental changes, presence of
marine preserves and possible harvest limits are discussed.
The Packaging Problem: Bivalve Prey Selection and Prey Entry Techniques of
Enteroctopus dofleini (Cephalopoda: Octopodidae)
Roland C. Anderson and Jennifer A. blather
'The Seattle Aquarium, 1483 Alaskan Way, Seattle, WA 98101
2Behavior and Evolution Research Group, University of Lethbridge,
4401 University Dr., Lethbridge, Alberta, Canada T1K 3M4
When an octopus finds a clam its problems with getting at the food inside are not over, as
it still has to get between the hard shells. When Enteroctopus dofleini was offered the mussel
Mytilus trossulus and the clams Venerupis philippinarum and Protothaca staminea, it solved the
penetration problem differently for each prey species. Octopuses usually pulled apart the shells
of Venerupis. Thinner Mytilus shells were equally often broken, chipped at the edges, or pulled
apart. The thicker Protothaca shells were chipped or had a hole drilled in them with the radula
and the salivary papilla. Tests of clam strength showed Protothaca the strongest in holding their
shells together. When Venerupis shells were wired shut, the octopuses resorted to chipping or
drilling instead of pulling. Thus these octopuses have four ways of getting into a clam, and used
the easiest method possible, resorting to drilling only when other methods were unsuccessful.
Monospecific Fossil Assemblages: Distinguishing Between Accumulation
and Aggregation Using Phylogeny and Paleobiology
Audrey Aronowsky and Laurie C. Anderson
Department of Geology and Geophysics, E235 Howe-Russell Geoscience Complex,
Louisiana State University, Baton Rouge, LA 70803
audrev@geol.lsu.edu
Dense monospecific assemblages are common in certain living and fossil molluscan taxa
such as turritellid gastropods, pectinid bivalves, and corbulid bivalves. These occurrences can be
attributed to physical or biological factors. Physical factors leading to monospecific
accumulations are generally post-mortem and include winnowing, dissolution, and transport.
Biological factors leading to monospecific aggregations generally relate to recruitment and
development. Detailed field and laboratory examination of the fossils can refute hypotheses
related to physical factors, but often are equivocal for hypotheses related to biological factors,
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 14
particularly for taxa with features suggestive of indirect development. Biological factors are
better tested with paleobiology and extant phylogenetic bracketing. Bracketing is particularly
useful in clades that vary in their tendency to form monospecific aggregations, such as corbulid
bivalves. Living corbulids such as Varicorbula disparilis form large byssally-attached masses,
and their close fossil relatives (e.g. Varicorbula caloosae) tend to be found in monospecific
aggregations. Other shallow-burrowing corbulids in which the byssus plays a less important
role, such as Corbula contracta, are rarely found as aggregations. Once the biological origin for
an aggregation has been established, we can begin to address related questions including why it
occurs in a particular place and/or time.
Extinction and the Life History of Unionid Bivalves
Chris Barnhart
Department of Biology, Southwest Missouri State University, 901 S. National Ave., Springfield, MO 65804
chrisbamhart@smsu.edu
Freshwater mollusks are disproportionately represented among recent extinctions. In
North America, estimates of historical extinctions of freshwater bivalves (Unionidae) range from
21-37 species, or about 10% of the pre-settlement fauna. Many more extinctions are impending.
Reasons for this decline are complex and mainly involve anthropogenic habitat destruction and
fragmentation. The dependence of unionids on particular species of fish as hosts for parasitic
larva development is an unusual example of “habitat” specialization that may contribute to
vulnerability and that complicates efforts to define diversity and conservation priorities. Recent
studies of host specificity indicate that some morphologically defined unionid species consist of
multiple species or at least host races, which are differentiated by their adaptation to sympatric
host fish species and populations. Such differentiation is expected to be most pronounced in
mussels that utilize geographically fragmented and genetically diverse host populations. In the
unionid morphospecies Cyprogenia aberti, for example, mussel populations in different
drainages are able to utilize local populations of several species of darters ( Etheostoma , Percina)
but generally not populations or species from other drainages. Both host specificity and genetic
evidence indicate that C. aberti consists of 3-4 species. Reliance on particular host species or
populations probably increases extinction risks for unionids because they share vulnerabilities of
the host species as well as their own. However, the hypothesis that host abundance, host
genetics, or particular aspects of the host-parasite relationship are responsible for unionid
declines is generally untested.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Gametogenesis and Fecundity of Atrina maura
in Laguna de San Ignacio, Baja California Sur, Mexico
Daniela Barrios Ruiz and Carlos Caceres Martinez
Universidad Autonoma de Baja California Sur, AP 19-B, La Paz, B.C.S. 23080, Mexico
dbarrios@uabcs.mx. ccaceres@uabcs.mx
Pen Shell, Atrina maura, fisheries in Baja California peninsula increased lately, so it is
important to study fisheries development and the knowledge of its reproductive process for
natural populations management for sustainable exploitation and to establish the seed production
in laboratory. San Ignacio Lagoon, Baja California Sur, is the most important capture zone. From
2000 2003, Monthly, meristic data, volumetric condition (IC), & muscle yield (IRM) indices
were obtained, and oocyte diameters measured of seven individuals. Seston and temperature
were recorded. Seston values were not related to temperature during the study. Values were high
due to the oligotrophic nature of the lagoon. We found a small relationship between IC and IRM,
nevertheless, while IC indicates increase in the body volume in valvar cavity in winter and
spring, gametogenesis never stopped. IC is not a positively linked index to the gonadic maturity.
Inverse relationship between IC and IRM suggests that when size muscle increases, the body
volume decreases. Years 2000, 2002 and 2003 showed continuous spawns and all stages of
oocytes. But 2001 showed no oocytes in reabsortion stage, suggesting the gonad acts like a store
organ. This sets A. maura like an opportunistic species assuring its reproduction and basal
metabolism. Fecundity showed more than 1000 million mature oocytes and 15,000 xlO9
spermatozoids. These values seem very high, however they correspond to the total number of
gametes inside the gonad (weight 1 00-400g), and not the ones that are spawned due to assure the
survival of the species.
Reproductive Effort of Atrina maura
in Laguna de San Ignacio, Baja California Sur, Mexico
Daniela Barrios Ruiz and Carlos Caceres Martinez
Universidad Autonoma de Baja California Sur, AP 19-B, La Paz, B.C.S. 23080, Mexico
dbarrios@uabcs.mx. ccaceres@uabcs.mx
There are many available qualitative studies describing reproductive cycles in bivalves,
but few quantitative data to observe reproductive effort because of the complexity of its gonad;
however, they are important for growth modelization, fishery, biology, and natural populations
management for sustainable exploitation. To solve this problem, we present an original method
associating histology, stereology and image analysis techniques determining in a quantitative
way the gonadic growth in bivalves. From 2002 to 2003 stereology (Cavalieri's principle) was
used, and biochemical analyses were determined for energetical values to give the reproductive
effort in seven organisms of Atrina maura. Gonadal tissue occupational percentage and volume
was predominant, followed by digestive gland. Both springs showed superior values. Gonad
biomass constitutes a quantitative gonadic index showing the development of the annual
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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1
reproductive cycle in this species with developed gonad in spring. The main total energy
contributors in A. maura were gonad and digestive gland, while muscle was always low.
Reproductive effort represents 200% of total energetic content of the animal. Warm temperatures
seem to be the reason. Traditional methods would not confirm gametogenesis through the year
accurately. This tool gives us a different scope to find out with precision the period of the year
when the most important reproductive event takes place. The difficulty of distinguishing the
reproductive periods in species like A. maura that are subject of commercial overexploitation
makes them fragile and moves them away from a sustainable practice. This work seeks to
establish the ban on collecting during the spring season to develop a sustainable fishery.
Morphological and Behavioral Defenses
in Three Species of Whelks in the Genus Nucella
Paul E. Bourdeau
Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 1 1794-5245
bourdeau@iife.bio.sunvsb.edu
In contrast to the numerous studies that have examined gastropod shell defenses and
defensive behaviors in isolation, few studies have examined the relationship between
antipredator behaviors and morphological defenses (size and shell shape) that influence prey
vulnerability. I examined the relationship between antipredator behavior and morphological
defense in three closely related marine gastropods in the genus Nucella. The three species differ
in their degree of morphological defense (shell thickness) and susceptibility to a common crab
predator Cancer productus. In agreement with other studies, results showed that thinner shelled
species were most susceptible to crab predation. In contrast with other studies, the species with
the strongest morphological defense did not exhibit the least behavioral avoidance. Instead, the
most morphologically defended species also exhibited the strongest behavioral response to crab
predator cues. Within a species, small, more vulnerable individuals showed stronger anitpredator
behavior than large individuals. Thick- and thin-shelled individuals did not differ in antipredator
behavior suggesting no relationship between behavior and shell thickness. Differences in the
relationship between defensive traits among and within species suggest that more studies
exploring the relationship between morphology and behavior are needed to understand the
evolutionary and ecological importance of gastropod responses to predators.
Molecular Systematics of Problematic Unionids
David C. Campbell
Biodiversity and Systematics, 425 Scientific Collections, Department of Biological Sciences, University of
Alabama, Box 870345, Tuscaloosa AL 35487-0345
amblema@bama.ua.edu
The combination of high ecophenotypic variation, geographic variation, and rarity in
many unionid species have contributed to uncertainty about their systematics. Use of DNA
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 17
sequencing of the ITS1, coxl , 16S, and nadhl regions reveal that Lasmigona holstonia as
currently recognized is a species complex, with Coosa and Caney Fork system populations both
distinct from the Tennessee and New populations. Recognition of species in Toxolasma and
Elliptio has ranged from extreme splitting to extreme lumping; molecular data support an
intermediate level of species diversity. “ Obovaria ” olivaria appears relatively distinct from
other “Obovaria” species, in agreement with Simpson’s recognition of a distinct genus for it.
Fusconaia species show strong biogeographic patterns in their distribution; relationships within
the flava-cerina-askewi complex remain unclear. Frequent genetic differentiation of populations
from different river systems suggests that geographically isolated populations of supposedly
widespread species deserve close scrutiny.
Molluscan Faunas and Zoogeography of the Georgia Neogene
Lyle D. Campbell and Sarah C. Campbell
Division of Natural Sciences and Engineering, USC Upstate,
800 University Way, Spartanburg, SC 29303-4999
lcampbeil@uscupstate.edu: scampbell@uscupstate.edu
Western Atlantic Neogene marine deposits were notoriously patchy from New Jersey
south to the Florida Keys and around the Gulf to the Florida Panhandle. Major gaps in the
Pliocene record occurred between Charleston, South Carolina and Daytona Beach, Florida, and
again between Tampa and the Panhandle. Middle Miocene outcrops and spoil were found in
Maryland, Aurora, North Carolina, and the Florida Panhandle. Literature documented only three
macro-invertebrate species from the Miocene, and about forty from the Pliocene of eastern
Georgia. Based on our study of the Kirby collection from Brunswick, Georgia, we can now
document more than 90 Charlton molluscan species (middle Miocene); over 30 Goose Creek
Limestone and 100 Raysor Marl species (early Pliocene); over 100 Duplin species (middle
Pliocene); three Waccamaw or equivalent species (late Pliocene), and over 100 Late Pleistocene
species. The Charlton fauna shared numerous species with the Chipola fauna from the
Panhandle. Both were fully tropical, based on an abundance of Vasum, Turbinella, and
Melongena. Only two molluscan species, one coral and a sand dollar were shared with the time
equivalent, but cooler, Maryland Miocene faunas. This argued for faunal interchange between
the Gulf and Atlantic through the Suwannee Strait during middle Miocene time. In contrast, the
Georgia Pliocene faunas more strongly correlated with the subtropical Carolinian province.
Cyclocardia and Astarte were abundant, and the species richness of Conus and other gastropods
reflected patterns of Carolinian diversity, not the rich tropical diversity recorded from southern
Floridian strata.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Systematics and Phylogenetics of the Family Streptacididae (Gastropoda: Heterobranchia)
from Devonian through Triassic Marine Strata
Matthew R. Campbell
Department of Geological Sciences, Indiana University - Bloomington,
1001 E 10th St, Bloomington, IN 47405-1403
ecphora@indiana.edu
Streptacididae is among the earliest families in the subclass Heterobranchia, an abundant
and ubiquitous subclass of fossil and modern Mollusca. In the Paleozoic, the subclass
Heterobranchia contains one informal group with two genera and two species in the Early and
Middle Devonian, one family with one genus and one species in the Permian, and the family
Streptacididae with seven genera and about 85 species from the Middle Devonian to the Triassic
and possibly from the Cretaceous. The family Streptacididae is characterized by a heterostrophic
protoconch, small size (0.4 to 14 mm), and an elongate shape. Streptacididae survived both the
Late Devonian and Permo-Triassic extinctions.
The family Streptacididae is a basal member of the superfamily Pyramidelloidea based on
preliminary cladistic analyses. Splitting the genus Donaldina into additional genera is not
supported by cladistic analyses. Taxonomic assignments are revised based on protoconch
morphology, spiral ornamentation, and other shell characters. Streptacis and Donaldina are
considered to be distinct at the genus rather than family rank, and family Streptacididae is
assigned to the superfamily Pyramidelloidea. Authors have proposed that the genus Jiangxispira
was an evolutionary connection between the family Streptacididae and the Mesozoic superfamily
Cylindrobullinoidea, which likely were basal opisthobranchs.
Mysella pedroana , Not Another Host-specific Bivalve
Shannon M. Carpenter
Santa Barbara Museum of Natural History, Department of Invertebrate Zoology,
2559 Puesta del Sol Road, Santa Barbara, CA 93 1 05-2998
scarpenter@sbnature2 .org
Mysella pedroana (Dali, 1898) lives commensally on Isocheles pilosus (Holmes, 1900)
and Blepharipoda occidentalis Randall, 1839. Specimens attached to Isocheles pilosus were
previously thought to belong to an undescribed species, because of their small size at
reproductive maturity and have been referred to in the literature as Mysella sp. H. However,
once the variability of dentition and internal structure of small Mysella pedroana and Mysella sp.
H were compared, it was determined that the two were in fact the same species. The prevalence
of Mysella pedroana was higher on B. occidentalis than on I. pilosus. Those on B. occidentalis
were also larger in the gill chambers compared to only juveniles found in the gills of I. pilosus.
Variability of characters, including size at reproductive maturity and shell morphology, indicates
that Mysella pedroana is a highly variable species. The identification of this bivalve as Mysella
pedroana is perhaps due to the continuing research on the symbiont and host relationship.
Reported host specificity for commensal bivalves may be due to the lack of study or
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 19
experimental observations. This species was previously thought to be host specific, but this
assumption has been shown to be invalid.
Reevaluating the Facelinidae: Systematics and Phylogeny
Jamie M. Chan and Terrence M. Gosliner
Department of Invertebrate Zoology and Geology, California Academy of Sciences,
55 Music Concourse Dr., Golden Gate Park, San Francisco, CA 94103
The goal of my study (Chan) is to complete a phylogenetic analysis of a major family of
aeolids, the Facelinidae, and more spe cifically the genus Facelina. Many species have been
described but no revision is available for Facelinidae or even the genus Facelina. At least 15
species of Facelina from the Indo-Pacific tropics remain undescribed. The reason why this study
will focus on Facelina is because this is the most diverse genus of the family, which includes
approximately one third of the known species of Facelinidae. Presently, they may not constitute
a monophyletic group. Generic boundaries are poorly circumscribed and have not been tested
phylogenetically. Many of the existing species descriptions are incomplete or vague. We
examine the use of novel anatomical characters such as jaw elements, genital armature,
accessory glands and modified cerata in further resolving the distinction between Facelina
species.
A Preliminary Study of the Biology
of Veronicella sloanei (Cuvier, 1817) in Barbados
Nickelia Clarke and H. Angela Fields1
’Department of Biological & Chemical Sciences,
University of the West Indies, Cave Hill, Barbados
afieids@uwichill.edu.bb
In Barbados, in the first half of the twentieth century, plant damage caused by slugs was
deemed to be “annoying but not economically serious.” However, by 1950 slug populations and
slug damage appear to have increased, as records show that in 1951 a search for parasites
suitable for the biological control of Veronicella was undertaken. None were found and today
slugs, particularly Veronicella sloanei , are still an important pest in gardens and plant nurseries
in Barbados. Research into the biology of Veronicella sloanei was carried out in the 1980s, but
the results were never published and have since been lost. In the present study ad libitum
sampling of animals in the field, and focal animal sampling and scan sampling of slugs held in
aquaria were employed to collect data on the activity budget and mating behaviour of V sloanei.
Slugs were examined for the presence of an inflated bursa copulatrix, a condition that, in this
study, was used as evidence of prior sexual activity. Egg clutches found in the field and those
produced by captive slugs were incubated and the hatchlings were reared in aquaria. Preliminary
data reveal that slugs are active, and will feed, throughout the night until just before dawn. Both
in the field and in the laboratory, Veronicella sloanei was found to mate in pairs, in triplets or in
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 20
groups. An inflated bursa copulatrix was most commonly found in animals with a contracted
length of greater than 40 mm.
Partula: the Birth and Death of Species
i <y
Bryan Clarke and James Murray
'institute of Genetics, Queens Medical Centre, Clifton Boulevard,
Nottingham NG7 2UH, England
department of Biology, University of Virginia, Gilmer Hall, Charlottesville, VA 22904-4328
bnan.ciarke@nottingharn.ac.uk
Partulid land snails have been unusually informative about the mechanisms of speciation,
and recently they have become an exemplar of invertebrate conservation. Here we review the
evolution and extinction of Partula species, with an emphasis on some unanswered, or partially
answered, questions:
1) Where did the Partulids come from?
2) What caused the exceptional flowering of color and pattern polymorphisms in Eastern
Polynesia?
3) What were the modes of speciation, and how did the species diverge?
4) Why were the Partulids of the Society Islands so susceptible to the introduced
carnivore Euglandina rosea ?
5) How can we save at least some of them?
6) If we cannot save them, what else can we do?
We will give some tentative answers.
Molecular Insights into Biogeographic Patterns of Speciationin Marine Molluscs
Rachel Collin
Smithsonian Tropical Research Institute, unit 0948, APO AA 34002
coUinr@naos.si.edu
Speciation is generally thought to occur as a result of geographic separation that causes a
disruption in dispersal and gene flow between populations. It is difficult to imagine effective
geographic barriers to dispersal in the ocean, especially for species with planktonic larvae.
However many studies of marine animals, such as echinoderms and fishes seem to support such
a pattern of allopatric speciation. Published molecular phylogenetic studies of marine molluscs
show that patterns of speciation depend on the taxonomic group and on the region of the world in
which the phylogeographic patterns are studied. Research from the Indo-Pacific show a pattern
of allopatry between sister species and many small areas of regional endemism and cases with
more distantly related species occurring in sympatry. Studies along the Pacific coast of the
Americas support a situation where many sister species occur in sympatry. Comparisons across
datasets show that those species that occur in sympatry are generally separated by smaller
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 2 1
genetic distances than those that are allopatric but that divergences also correlate across
geographic region. This suggests that the tempo and mode of speciation varies geographically.
Partulids on Tahiti:
an Interesting Distribution among Surviving Populations
Trevor Coote and Walter Teamotuaitau
Partulid Fieldwork Programme Consortium, B. P.2407, Papeete, Tahiti, French Polynesia
partula2003@vahoo.co.uk
The extinction of numerous species of endemic land snails in French Polynesia due to the
introduction of the carnivorous Euglandina rosea is a salutary lesson in panic biological control
undertaken without adequate scientific field trials. Less than 20 of the original 70+ species of the
family Partulidae survive on maybe a dozen of the original 17 islands which were previously
host to partulids. Last year surveys were carried out in over 60 of the valleys of Tahiti. All of the
populations found were of the Partula hyalina/clara sister lineage which previously accounted
for only 5-10% of the individuals collected in scientific studies before the introduction of E.
rosea. No individuals of the Partula otaheitana/affinis complex were found (over 90% of
previous collections) in any valleys, yet these species still survive in many montane forest areas
(over 1000 m altitude). Partula nodosa , with a previous distribution of just 7 valleys, is most
likely extinct in the wild but persists well in captive populations. Partula fdosa, Partula
producta, and Partula cytherea (all previously with a single valley distribution) are almost
certainly extinct, as are Samoana jackieburchi and Samoana burchi. Samoana attenuata, also
surviving on Moorea, is very rare but widely distributed.
Morphological Variation in Allopatric Populations of
Acanthina and Nerita Gastropods in the Northern Gulf of California
Raena Cota, Allison Gilliland, Shannon O’Hara, Urs Riner, Michael Lorentzen, Ryan Horenziak,
Emerald Tataryn and Stephen Shuster
Northern Arizona University, 2625 N. King St., Flagstaff, AZ 86004
Geographically separated populations often exhibit distinct phenotypes. These
differences could be attributed to changes in environmental conditions among sites, genetic
effects between populations, or an interaction of the two (GxE). To address this issue we
examined morphological variation in three disjunct populations of two gastropod species, the
unicorn snail, Acanthina sp., and a nerite, Nerita sp., near Puerto Penasco, Sonora, Mexico. The
three populations included, (1) Estero Morua, where comparatively large snails were isolated on
a coquina limestone island near the mouth of the sandy estero habitat; (2) Punta Penasco, where
smaller snails were wide spread on the basalt boulders in the upper intertidal zone; (3) Punta
Pelicano, where small and medium sized snails were clustered on granitic outcrops in the middle
intertidal zone. We measured five morphological shell characteristics for Acanthina (shell
height, shell width, aperture height, aperture width, labial spine length) and eight for Nerita
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 22
(shell height, shell width, aperture height, aperture width, medial tooth length, lateral tooth
length, whorl height, operculum length). Principal components analysis (PC A) showed
significant morphological differences among the three populations of Acanthina (A=.43, P<.Q01)
and Nerita (A=.68, P<.001); snails from Estero Morua were markedly larger than the other two
populations, which were similar in size within each genus. These results suggest that snails in
Estero Morua are geographically isolated from the other two locations.
Persistence of a Native Brackish-water Hydrobiid Snail Population in Certain Restored
Marshes of Southern Suisun Bay, San Francisco Estuary
Cheryl L. Davis and Christopher L. Kitting
Department of Biology, California State University East Bay, Hayward, CA, 94542
ckitting@csuhavward.edu
We monitored aquatic invertebrates approximately monthly for over three years (since
1999) and then semi-annually in restored and reference brackish marshes in southern Suisun Bay
of San Francisco Estuary. Several sites with marsh tidal pools yielded numerous aquatic
invertebrates on modified mesh minnow traps, and thriving hydrobiid snails, related to Tryonia
imitator, the endangered west coast brackish water snail. Possible identifications are Tryonia sp.
or Hydrobia andersoni (described only from fossils up the ancient San Joaquin River). Core
samples taken in mud yielded dead eroded snail shells as deep as 130 cm in the ancient peat soil,
indicating these snails are native (due to slow sedimentation rates at this site). Subsequent
seasonal sampling for approximately a year (2002-2003) at the same site yielded consistently
high densities of snails, an average of approximately 200-300 snails per 25 cm2 in mud and 60-
80 per 25 cm2 on vegetation. Juvenile snails (represented as snails with shell lengths of < 0.50
mm) occurred in most seasons. In the lab, these snails brooded their young and were observed
feeding on filamentous algae, diatoms, and cyanobacteria. They tolerated sudden shifts in
salinity and many snails (>2.0 mm shell length) survived for approximately a year in the
laboratory. Since these hydrobiid snails persisted for at least -five years, demonstrated seasonal
recruitment, high average seasonal densities for over a year, and were abundant with other
aquatic invertebrates, marsh tidal pools seem to be an important feature in restoring common,
persistent, and possibly ancient assemblages of native aquatic invertebrates.
Predation by Euglandina rosea on Local versus Non-local Gastropods:
No Differences in Mucus Trail Following?
Elizabeth C. Davis
Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045
bethd@ku.edu
Carnivorous snails, such as Euglandina rosea, have been used unsuccessfully as
biocontrol agents in Hawai’i and other Pacific islands in an attempt to control the giant African
land snail, Achatina fulica. Euglandina rosea is native to the Southeastern United States, and is
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 23
able to follow the mucus trails of its prey. Although there have been experiments on food
choice, it is not known if the ability of Euglandina rosea to follow mucus trails differs with snail
pray species. This study compared the ability of E. rosea to follow trails of two groups of
gastropods: those found within its local habitat (Southeastern USA) and those not found within
its native range (Kansas). Each predator (n = 10) was tested against eight species of gastropods
(four species from each area) and three individuals of each species. The results of the study
indicate a high level of individual variation of predator behavior, and that gastropods from
Florida and Kansas were followed at almost the same frequency by the ten predators tested.
A Survey of Aquatic and Terrestrial Gastropods in Kansas:
The Nature Conservancy’s Welda Prairie and the Fitch Natural History Reservation
1 70 r TToi n o
JUHZ.UUVU1 A/, iyav 10
Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045
bethd@ku.edu
A preliminary survey of two areas, Welda Prairie and Fitch Natural History Reservation,
were conducted in 2004 - 2005. Each area was sampled at two terrestrial sites, and one aquatic
site using meter sampling grids and a general survey for larger gastropods around the sites. All
sites were identified with GPS coordinates and were of different habitats to better sample the
diversity of mollusks found in the small survey. The Welda site has never been previously
sampled for gastropods and will be used to provide baseline data on the diversity of this Nature
Conservancy site. The Fitch area was last surveyed in the 1950’s and has been allowed to
undergo succession. This survey will examine changes in species composition and results will
be added to databases at the Kansas Biological survey. This study has been supported by two
grants from the University of Kansas Field Station and Ecological Reserves.
Sex and Darts in Slugs and Snails
Angus Davison
Institute of Genetics, School of Biology, University of Nottingham, Nottingham, NG7 2UH, UK
angus.davison@nott.ac.uk: http^/vvuvv moiluscs.ora'
In the final stages of an elaborate courtship, many slugs and snails shoot “love” darts into
' each other. While darts improve the reproductive success of the shooter, it is unclear why some
species have darts and others do not. In fact, dart use has barely been studied except in the
garden snail Cantareus aspersus (Helix aspersa ). We therefore took an evolutionary approach to
attempt to understand the use of darts, by investigating mating behaviour in a range of species.
The prediction was that, because darts could have arisen out of an escalating cycle of sperm
digestion and investment in sperm, then darts should be found in taxa that enforce simultaneous
reciprocity during mating. Mating behaviour in 60 genera of land snails and slugs was recorded,
and compared against dart use and a phylogeny. “Face-to-face” simultaneous reciprocal-mating
behaviour is restricted to three monophyletic groups of snails and slugs, and dart-bearing species
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 24
are a subset within the same clades, which suggests a link, though not necessarily a causal one.
As yet, we are unable to quantify the extent to which darts or mating behaviour are determined
by common ancestry or regimes of natural or sexual selection, because the current phylogeny
lacks resolution. However, the results emphasise that to understand the use of darts, then data are
required from a wide range of species. The realization that several characters are correlated may
stimulate further research, and could eventually lead to some testable models for dart and mating
behaviour evolution.
Needs and Predictions for 21st Century Molluscan Alpha-Taxonomy
Benoit Dayrat
California Academy of Sciences, 55 Music Concourse Dr., San Francisco, CA 94549,
and University of California, Merced, P.O. Box 2039, Merced, CA 95344
bdavrat@calacademv.org
Based on taxonomic revisions of several groups of discodorid sea slugs, such as
Discodoris, Peltodoris, Paradoris and Geitodoris (Mollusca, Gastropoda, Euthyneura,
Nudibranchia, Doridina), I will discuss some urgent needs in nudibranch — and more broadly
molluscan — alpha-taxonomy. Some of those needs are: 1) the ending of several practices, such
as naming new species based on one or very few specimens; 2) the establishment of exhaustive
revisions as the standard form of taxonomic contributions, instead of brief, isolated species
descriptions; 3) the use of an integrative approach to species delineation as often as possible with
different kinds of data and methods, such as morphology and phylogeography (this should be
mandatory in cases where morphology provides dubious results); 4) the identification of species
that are hardly identifiable with morphology through other techniques, such as DNA barcoding.
However, for several reasons, future taxonomic practices may not consider or answer all of those
needs. I will discuss whether or not we can make predictions on what molluscan alpha-taxonomy
will be in the 21st century.
Empirical Estimates of Reproductive Isolation among the Freshwater Pulmonate Snails
Physa acuta , P. pomilia and P. hendersoni
Robert T. Dillon, Jr. , John D. Robinson and Amy R. Wethington
'Department of Biology, College of Charleston, Charleston, SC 29424
dillonr@eofc.edu
department of Biological Sciences, Purdue University, West Lafayette, fN 47907
Physa hendersoni (Clench 1925) collected from its type locality near Yemassee, South
Carolina, and Physa pomilia (Conrad 1834) from its type locality near Claiborne, Alabama, both
display the penial morphology characterized as “type b/c” by George Te. Mate choice tests
returned no evidence of premating reproductive isolation between these two populations, and no-
choice breeding experiments confirmed outcross fecundity, FI viability, and FI fertility
comparable to incross controls. Significant premating reproductive isolation does occur,
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 25
however, between the Yemassee population and Physa acuta from our standard Charleston
population, bearing the “type c” penial morphology. No-choice breeding experiments involving
Yemassee and Charleston snails returned a mixture of hybrid and selfed progeny, the hybrids
proving sterile. Thus the nomen Physa hendersoni is a junior synonym of P. pomilia, while P.
pomilia and P. acuta are distinct biological species.
Phylogeny and Comparative Phylogeography of West Coast Chitons
Douglas J. Eemisse and Ryan P. Kelly
'Department of Biological Science, California State University, Fullerton, CA 92834
deemisse@fullerton.edu
department of Ecology, Evolution, and Environmental Biology, Columbia University,
and Department of Invertebrate Zoology, Molecular Systematics Laboratory,
American Museum of Natural History, Central Park West at 79th St.. New York, NY 10024
In order to understand patterns of historic and ongoing speciation events in West Coast
marine animals, we have sequenced multiple gene regions for multiple individuals of one or
more populations of most shallow- water species of all 16 chiton genera occurring on the West
Coast: Leptochiton, Oldroydia, Stenoplax , Lepidozona, Callistochiton, Chaetopleura,
Acanthochitona, Cyanoplax , Nuttallina, Schizoplax , Placiphorella, Katharina, Tonicella,
Cryptochiton, Dendrochiton and Mopalia. Chitons are well suited as models for understanding
speciation in the northern Pacific. There are many species, they are relatively diverse in
morphology and feeding ecology, and there have been multiple independent radiations of
species. Present and previous sequence results have revealed that most of these radiations are
restricted to the northern Pacific or only more recently spread to other seas such as the northern
Atlantic or Arctic. If available fossil evidence is accepted at face value then the northern Pacific
chiton fauna has arisen remarkably recently. Few of these species are known from even the
Pliocene. The West Coast, where the chiton fauna is especially diverse, has quite homogenous
environmental conditions, so it is curious how so many speciation events could have occurred in
so little time. For example, we have sequenced 20 Mopalia spp. from the vicinity of Monterey
alone. Our comparative phylogeographic analysis could reveal whether particular discontinuities
along the coast correspond to pronounced genetic separation in multiple species of chitons, and
thus could be in part responsible for promoting speciation in chitons as well as other similar
marine animals.
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Evolution of Poecilogony from Planktotrophy: Speciation in the Sea Slug Genus Alderia
Ryan A. Ellingson and Patrick J. Krug
California State University, Los Angeles, CA 90032-8201
n-anellingson@gmail.com
Variable development within a single species (poecilogony) is a rare phenomenon, and
putative examples often comprise cryptic species. The sacoglossan genus Alderia contains a
single recognized species in north Atlantic and Pacific estuaries; it is planktotrophic throughout
its distribution except in California, where both planktotrophy and lecithotrophy are expressed.
We present molecular, morphological and developmental data that populations south of Bodega
Harbor comprise a true poecilogonous species, distinct from the strictly planktotrophic congener
A. modesta. Northern populations (Bodega to Vancouver) consist of large adults with a smooth
dorsum that produce planktotrophic larvae; those from Tomales Bay south consist of smaller
adults with a raised dorsum that seasonally toggle between planktotrophy and lecithotrophy.
Sequences of the mitochondrial cytochrome oxidase I gene were obtained from 204 individuals
from 14 populations. Northern and southern haplotypes formed reciprocally monophyletic
clades differing by 16-20%, including fixed differences at 36 of 480 sites. Molecular clock
calibration indicates the species diverged in the early Pleistocene (1.4 million years ago). The
northern species is absent from the south of Tomales Bay yet common only 4 km away, and was
rare in San Francisco Bay until recruiting in large numbers in Feb. 2005; population dynamics
may reflect differential colonization of, or adult survival on, regionally distinct strains of the host
algae Vaucheria spp. Southern Vaucheria strains may limit slug body size, selecting against
planktotrophy in the southern species by limiting fecundity in the face of high planktonic
mortality. Molecular comparisons with Atlantic and eastern Pacific material will be discussed.
Phylogeography and Genetic Population Structure of Vermetids in Hawai’i
Anuschka Faucci
Kewalo Marine Laboratory, University of Hawai’i, Honolulu HI 96826
anuschka@hawai i .edu
Many marine organisms have a high dispersal potential especially during their larval
stage. Population genetic data can be used as an indirect measure of realized larval dispersal.
Studies correlating genetic differentiation with life history traits like dispersal ability have shown
that, in general, high dispersal potential is associated with lack of genetic differentiation among
populations. However, there are exceptions to this simple rule due to case specific biological and
physical reasons. Vermetids are sessile, suspension-feeding gastropods found in shallow marine
waters. They show a wide range of developmental patterns from obligate, pelagic planktotrophic
larvae, which reside in the plankton for several weeks, to species with direct developing benthic
juveniles, which lack a planktonic phase. The Vermetidae in HawaPi comprise nine species.
Most species are locally abundant and distributed throughout the Hawaiian Archipelago. A 569-
base pair region of the mitochondrial gene cytochrome oxidase I (COI) was sequenced for the
nine species from most Hawaiian Islands, including the Northwestern Hawaiian Islands. Species
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with direct development show highly structured populations throughout the Hawaiian
Archipelago, suggesting very limited to no dispersal among islands. Furthermore, the vermetids
appear to have colonized the Hawaiian Islands via the hypothesized French Frigate Shoals-
Johnston Atoll connection, with a subsequent radiation into the remainder of the Archipelago.
Preliminary Report of the Terrestrial Molluscan Fauna of the Eastern Caribbean islands,
and Trinidad & Tobago
1 9
H. Angela Fields and David G. Robinson
'Department of Biological & Chemical Sciences,
University of the West Indies, Cave Hill, Barbados
afields@uwichiil.edu.bb
“ USDA APHIS PPQ/ Academy of Natural Sciences, Philadelphia, PA 19103
The islands of the Eastern Caribbean, with the exception of Barbados, are part of an
island arc system that stretches from Sombrero in the north to Grenada in the south. There is an
inner volcanic arc of mountainous islands, and an outer arc of limestone islands, representing an
older, submerged volcanic chain. The relative age, relief, geology, rainfall patterns, and forest
cover on the islands have resulted in a wide variety of environments. In contrast, Trinidad and
Tobago were once part of the South American continent, and share the tectonic history of
northern Venezuela. All of these islands have suffered large-scale modification of their original
environments as a result of colonial occupation and more recently increasing population
densities. Between 2002 and 2005, twenty-one islands were visited and their malacofauna
surveyed. The faunas found are quite diverse with surprising levels of endemicity on some
islands, with at least sixteen endemic species on Dominica and at least one endemic on most of
the other islands. Revisions of some snail groups have become necessary with a number of new
species that are now being described, and some “lost” species have been re-discovered. Invasive
taxa are established on many islands and are an increasingly pervasive component of their
malacofauna.
Endemism, Introduced Species and Conservation in the Austral islands (French Polynesia)
Benoit Fontaine and Olivier Gargominy
Museum National d'Histoire Naturelle, Departement Systematique et Evolution - Malacologie
55 Rue Buffon, 75005, Paris, France
fontaine@mnhn.fr
With more than 300 described endemic species, the land snail fauna of French Polynesia
is of high conservation value. However, many species are extinct or threatened: 159 species from
the region are recorded as extinct by the IUCN. A biodiversity inventory was done in the Austral
Islands (French Polynesia), during which molluscs were sampled 70 years after the 1934 Bishop
Museum’s Mangarevan Expedition. Altogether, 248 taxa, 80% of which endemic, are now
known from the Austral Islands, most of them being small to minute species. More than two-
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thirds of the endemic species are now extinct, and alien mollusc species have appeared and are
much more widespread and abundant than indigenous ones. The main reason for endemic species
extinctions seems to be habitat degradation through agriculture and urbanisation, fires,
introduced goats and cattle and invasive plants. Euglandina rosea is present only in Tubuai,
where it has an impact on Partula hyalina, but has not yet reached the other Austral Islands.
Introduced carnivorous Streptaxidae have been found in all islands, but their impact is not
known, neither is the impact of other introduced invertebrates. The extreme fragmentation of
native habitat, together with the very small range of many endemic species poses a further threat
to their survival. Species new to science and already extinct have been discovered. All these facts
makes the IUCN figure a very optimistic one, which will greatly increase when updated. Relict
habitats for molluscs and other taxa have been discovered and proposed for conservation.
Ametamorphic Direct Development in Dendrodoris behrensi (Nudibranchia:
Dendrodorididae) from the Northeast Pacific Ocean,
with a Review of Developmental Mode in the family
Jeffrey H. R. Goddard
Marine Science Institute, University of California, Santa Barbara, California 93106
goddard@lifesci.ucsb.edu
Dendrodoris behrensi Millen and Bertsch, 2005, has ametamorphic direct development.
The embryos passed through a vestigial veliger stage lacking a shell, operculum, larval retractor
muscle and pedal sensory cilia. After an embryonic period of 38 days (16-19 °C) they hatched as
juveniles averaging 512 pm in dorsum length. Newly hatched juveniles possessed eyespots,
rudiments of the rhinophores, and a lattice of spicules on the ventral surface of the dorsum. Only
three other examples of direct development have been noted from nudibranchs from the
northeast Pacific Ocean, all from the Family Dendrodorididae.
Based on a survey of the literature, mode of development was determined for 26 species
and forms of dendrodoridids. Fifty percent of these taxa have planktotrophic development, 8%
lecithotrophic development, and 42% direct development. Direct development is significantly
more prevalent in the Dendrodorididae than reported for opisthobranchs worldwide. Three
hypotheses are presented to explain this: (1) direct development is adaptive in overcoming size
constraints on post-metamorphic, juvenile dendrodoridids stemming from their lack of a radula
and suctorial mode of feeding on sponges. (2) Direct development is prevalent because small
adult size, which is generally correlated with direct development in marine invertebrates, has
been selected for in many dendrodoridids. (3) Direct development is an adaptation against high
larval mortality in regions rich in dendrodoridids. Limited evidence tends to support hypotheses
2 and 3, but with some interesting developmental exceptions, not hypothesis 1.
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You can Teach Old Clams New Tricks: Reconstructing Patterns and Timing of Growth -
Methods and Applications
David H. Goodwin
Department of Geology and Geography, Denison University, Granville, OH 43023
goodwind@denison.edu
Bivalve mollusks are biological chart recorders: their shells contain a record of the
environmental conditions experienced during growth. Data is preserved in several forms,
principally by periodic growth increments and geochemical variations. Combined analysis of
these patterns is a powerful tool for understanding how bivalves grow, how growth reflects
environmental variation, and for reconstructing evolutionary relationships among taxa.
Cross-calibration of these archives from modem specimens with observed environmental
conditions reveals tight correlations with numerous physical and biological signals.
Sclerochronologic archives are, however, incomplete due to the onset of senescence. Growth
cessations and changing growth rates can reduce the range and resolution of the recorded
environmental conditions. Nevertheless, careful analysis reveals that numerous biological and
environmental signals are accurately preserved. Furthermore, shell-based environmental records
are easily modeled, providing baselines against which observed profiles could be compared.
Modeled profiles also elucidate which components of shell-based archives reflect actual
environmental conditions versus biologically mediated growth patterns specific to the individual
in question.
With a detailed understanding of an organism’s growth patterns, one can address a
variety of significant neontologic and paleontologic questions. Examples include, investigation
of both natural and anthropogenic biogeographic shifts, documenting climate change in the past,
predicting the biological responses to global warming, and reconstructing evolutionary
relationships.
Systematics and Phylogeny of Babakina (Nudibranchia: Aeolidoidea)
Terrence M. Gosliner , Manuel M. Gonzalez-Duarte and Juan Lucas Cervera
'Department of Invertebrate Zoology and Geology, California Academy of Sciences,
55 Music Concourse Dr., Golden Gate Park, San Francisco, CA 94118
tgosliner@calacdemv.org;
2Departamento de Biologia, Facuitaa de Ciencias dei Mar y Ambientales, Universidad de Cadiz, Poiigono dei Rio
San Pedro, s/n, Apdo. 40, 11510 Puerto Real (Cadiz), SPAIN
Babakina Roller, 1973 is known from the type species, Bahama festiva Roller, 1972
described from California and temperate Japan. Babakina caprinsulensis was described from a
single specimen collected from northern New Zealand. Ortea (1979) described Rioselleolis
anadoni from a single specimen from the northern coast of Spain. This species was later
considered to be a species of Babakina. Material from the southern Iberian peninsula, the
Canary Islands, the Bahamas, California, the Pacific coast of Mexico, southern Japan,
Philippines, Indonesia and the Hawaiian Islands was examined in this study. The results
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demonstrate that the three described species are differentiated by external and internal
anatomical differences. Additionally an undescribed species was recognized from the Indo-
Pacific tropical localities. Difference in the arrangement of the bursa copulatrix, receptaculum
seminis and shape of the penis are consistent between distinct species. The systematic position
of the Babakina has been the subject of some controversy. Several authors have considered it to
be a member of a distinct family, while others have placed it within the Glaucidae. A
preliminary phylogenetic analysis is presented to help clarify its systematic placement.
Babakina shares plesiomorphic features with members of the Flabellinidae including the
presence of two sperm storage sacs and a pleuroproctic anus, but shares apomorphies with more
derived aeolids, including the presence of a single row of radular teeth.
Mating Systems and Family Conflicts in a Marine Snail
Rick Grosberg
Center for Population Biology, University of California, Davis, CA 95616
rkgrosberg@ucdavis.edu
Few groups of organisms encompass greater diversity in mating systems, parental care,
and sibling interactions than gastropods. Why do females provide post-zygotic parental care in
most species, males in others, and both parents in a few? Why do siblings of some species
cooperate extensively, whereas others try to kill and consume each other? Are there predictable
associations between patterns of parental care and the nature of interactions among siblings?
How are multiway conflicts of interest among family members resolved? The mating system,
because it controls patterns of relationship among family members, is one of the keys to
answering such questions. Solenosteira macrospira is a buccinid whelk whose reproductive
biology embodies multiple forms of family conflict, and, consequently, offers an exceptional
opportunity to explore the constraints and opportunities for resolving such conflicts of interest.
S. macrospira females mate multiply, and package offspring in capsules, each containing 200-
300 siblings. As in other “neogastropods,” there is often extensive predation on sibling eggs,
zygotes, and embryos within egg capsules. Quite remarkably, female S. macrospira (and
perhaps other closely related cantharids) oviposit almost exclusively on males (>98%), and
virtually never on conspeciflc females or other objects. Brood carrying is risky to males,
because it increases their vulnerability to predators; but, it is also essential for brood survival. In
this talk, I will analyze the effects of the mating system on the evolution of male parental care
and the resolution of parent-offspring and sibling conflict in this, and other, polyandrous species.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Explaining Generic Endemism in the Pacific Coast Tertiary Mollusean Faunas
David Haasl1, Jann E. Vendetti1,2 and Carole S. Hickman1,2
Museum of Paleontology1 and Department of Integrative Biology2,
University of California, Berkeley, CA 94720
dhaasl@berkelev.edu
The pattern of origin and radiation of endemic genera is commonly associated with the
terrestrial biotas of oceanic islands. Endemicity is relatively rare among marine genera, as even
marine species tend to achieve broad geographic distribution in the relative absence of barriers to
larval dispersal or migration of benthic adults. During the Eocene, mollusean faunas of the
northeastern Pacific were tropical in aspect and composed of species in cosmopolitan genera. A
dramatic turnover in the mollusean fauna occurred at the Eocene-Oligocene transition. This
turnover is characterized by the appearance of many new genera, a rise in endemism, and the
origin of the modem North Pacific cool-water fauna. What requires explanation is the number of
genera in the turnover fauna that (a) remained endemic to the Northeastern Pacific, (b) became
abundant elements in mid-Tertiary faunas, (c) evolved rapidly as lineages of species that have
been the basis for biostratigraphic zonation and correlation, and (d) disappeared without giving
rise to new taxa. The most striking examples are caenogastropods, such as the buccinoidean
genera Molopophorus Gabb, 1864, and Bruclarkia Trask, 1926. Morphological analyses,
taxonomic revision, and phylogenetic analyses of these and similar genera will provide both a
comparative profile and a modem macroevolutionary perspective of this phenomenon.
Progress in the Conservation of Hawaiian Achatineiline Snails
Michael G. Hadfield
Kewalo Marine Laboratory, University of Hawai’i, 41 Ahui St., Honolulu, HI 96813
hadfieid@hawaii.edu
Hawai’i’s -750 species of endemic terrestrial and arboreal snails have experienced great
extinction, among the most severely impacted being members of the subfamily Achatinellinae.
Efforts over the last 30+ years to understand the causes of extinction, to monitor the survival of
species, and to conserve what remains of this spectacular radiation (-100 spp. in 4 genera)
include field-demographic studies of populations on four islands, monitoring a population of one
species within a predator exclosure, captive propagation, and population-genetic studies. The
O'ahu-endemic genus Achatinella has diminished from 41 species to about 9 at the present, 7 of
them represented among the 1,500 achatineiline snails from three genera in the tree-snail
laboratory. By monitoring climatic conditions in the field, we were able to establish “climates”
in environmental chambers that have encouraged population-growth demographics comparable
to field populations for most species. For others, species that seemingly live in almost identical
field situations, laboratory propagation is far less successful. Sample data for lab populations
include original (field-collected) vs. current numbers as follows: A. fuscobasis, 11/440; A.
decipiens, 12/38; A. lila, 4/296; and A. apexfulva, 14/12. Molecular genetic studies have been
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 32
used to guide conservation efforts, in the field and the laboratory, for A. mustelina, a model that
will be used for other species as well.
Larval Settlement in Response to Soluble Cues from the Benthos
Michael G. Hadfield1 and Mimi A. R. Koehl2
'Kewalo Marine Laboratory, University of Hawai’i, 41 Ahui St., Honolulu, HI 96813
hadfield@hawaii.edu
2Department of Integrative Biology, University of California, Berkeley, CA 94270
In laboratory studies, larvae of many benthic marine animals settle and metamorphose in
response to dissolved chemical cues released by benthic organisms. Veligers of the nudibranch
Phestilla sibogae were used to investigate whether such cues induce sufficiently rapid behavioral
responses to bring about settlement near suitable recruitment sites, in this case their
postmetamorphic prey, Porites compressa, an abundant coral on reefs in shallow, wave-
dominated habitats in Hawai’i. Video analyses of trajectories and speeds of larvae swimming
mid-water in aquaria revealed that larvae tend to cease swimming and sink in water conditioned
by P. compressa. As cue and larvae are mixed in the turbulent flow over a coral reef, the fine-
scale filamentous structure of cue concentrations in the water column translate into rapid
(seconds) on/off temporal patterns of cue encountered by microscopic larvae. Larvae tethered in
a miniflume and exposed to water velocities mimicking flow past freely swimming larvae were
videotaped while exposed to realistic temporal patterns of cue filaments. Larvae quickly
retracted the velum and ceased swimming in filaments of cue and resumed swimming when they
passed out of them, actions sufficient to bring rapid settlement onto the reef. Analyses of the data
derived from these studies provided a model that predicts settlement over fore- and mid-reef
areas. The prediction has been tested and found to be valid.
Preliminary Phylogenetic Assessment of Invasive Apple Snails in Asia and Beyond
Kenneth A. Hayes
Department of Zoology, University of Hawai’i-Manoa, Honolulu, HI 96822
khaves@hawaii .edu
The freshwater apple snail genus Pomacea (family Ampullariidae) has a native range
covering most of South and Central America and the southeastern U.S. Pomacea spp. have been
introduced widely in southern and eastern Asia, Hawai’i and other Pacific islands, and elsewhere
in the mainland U.S. In their introduced ranges they have become major pests of wetland crops,
notably rice and taro. The taxonomy of Pomacea , including the identity and precise geographic
origins of invasive populations, is poorly understood. This lack of understanding has
implications for research on many aspects of ampullariid biology, including development of
effective pest management programs. As part of a systematic study focusing on the genus
Pomacea, I am using DNA sequence data to investigate hypotheses concerning the geographic
origins, molecular systematics and genetic diversity of introduced populations. So far, 300
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Page 33
individuals representing at least 1 1 putative Pomacea species have been analyzed. Preliminary
results suggest possible cryptic species among the apple snails that have been introduced to S.E.
Asia. These data also suggest multiple independent introductions of the most common invasive
apple snail, P. canaliculata, contrary to anecdotal accounts of a single introduction spreading
throughout the region. Pomacea canaliculata collected in Hawai’i and numerous S.E. Asian
locations appears to have originated in Argentina, whereas snails from Thailand and Cambodia
are likely to have come from Brazil or elsewhere and may even be a different species. Overall,
the results indicate that at least four, possibly more, species of Pomacea have been introduced
into southern and eastern Asia.
Hybridization: Lofty Theories, Taxonomic Reality
Joseph Heller
Department of Evolution, Systematics and Ecology,
The Hebrew University of Jerusalem, Jerusalem 91904, Israel
heHer@vTns.huii.ac.ij
Evolutionary theory suggests that many hybrids are less fit than their parental species and
hence that hybrid populations are ephemeral, on a geological timescale. It is further commonly
suggested that most Holocene hybrid zones became established merely fifteen thousand years
ago.
Mollusks form a precise tool for investigating hybridization through time since the shell,
which may be preserved as a fossil, is also the feature upon which species level taxonomy may
be based. I exploit this combination of facts to investigate the taxonomy of Holocene Melanopsis
of the Jordan Valley; and to explore how long ago could hybrids be traced in the fossil record of
the Jordan Valley.
Holocene Melanopsis include two species, and the hybrids between them. Also at a 1.4
Myr old site in the Jordan Valley these same two species were found; and with them
intermediates. Their low frequency and chrono-distribution suggest they are hybrids, rather than
evolutionary transitions between species. These 1.4 Myr old fossils may be the earliest direct
evidence of hybridization among species in nature, that is still going on today in the same region
and aquatic system, among the same species. This is way beyond the “lifetime” commonly
suggested for hybridization and not in agreement with classic evolutionary thought.
Geologic and Evolutionary Context of Land Snail Diversity on Oceanic Islands
Carole S. Hickman
Department of Integrative Biology, University of California, Berkeley, CA 94720
Linear, age progressive chains of basalt islands and seamounts are the geological
hallmark of a long history of active intraplate volcanism as the Pacific plate has passed over
discrete hotspots. Multibeam sonar seafloor mapping, records of seismic and magmatic activity,
subsurface geophysical data, and geochronology reveal a repeated geologic sequence that
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Page 34
constrains the evolutionary life of the biota of any one island to less than 5 Ma. The geologic
model for origin and evolution of island archipelagos provides a unique opportunity to
investigate repeated patterns of infrequent colonization followed by intra-island speciation and
evolutionary radiation. The Hawaiian and Society Island archipelagos are the best examples of
hotspot chains and are also the most intensively studied, both geologically and biologically.
Endemism is a pervasive pattern in land snails. Four entire families (Endodontidae, Partulidae,
Amastridae, Achitenellidae) are endemic to Pacific Islands. Subfamilies and genera commonly
are endemic to individual archipelagos or single islands, while species typically are confined to
single islands. Six additional families (Succineidae, Pupillidae, Diplommatinidae, Helicinidae,
Assimineidae, and Helicarionidae) have undergone significant Pacific island radiations. Accurate
reconstructions of geologic history and phylogenetic relationships are of equal importance in
explaining modem geographic distributions. Hominid-induced extinctions seriously depleted
island land snail diversity before most of it could be documented. Unstudied museum collections
and a largely undocumented fossil record are key to resolving major gaps in our current
understanding.
Larval Dispersal and Modes of Speciation: Hypothesis Testing in Littorina
Paul A. Hohenlohe
Department of Zoology; Oregon State University, Corvallis, OR 97331
hohenlohe@qwest.net
Species in the marine gastropod genus Littorina differ in developmental mode and
therefore differ greatly in dispersal potential. These differences lead to predictions about rates
and modes of speciation. There is evidence for sympatric speciation by tidal height or wave
exposure in some clades within Littorina, while in others geographic distributions support
allopatric speciation. Here I test hypotheses about the mode of speciation that produced L.
scutulata and L. plena, sister species with wide-dispersing, planktotrophic larvae. Simulation
modeling of larval dispersal and ocean currents suggests plausible mechanisms for geographic
isolation and allopatric speciation. Relevant to other models of sympatric speciation in the
genus, data on the species’ relative distributions at both large (among-shore) and small (within-
shore) scales along the Pacific coast of North America provide estimates of the habitat separation
of precursor morphs in the common ancestor, allowing analysis of reproductive isolation and
divergent selection. With the current overlap of distributions at all scales, sympatric speciation
seems likely only if divergent selection at the time of speciation has since relaxed, allowing the
species to re-invade overlapping niches. Given estimates of the time since speciation and
possible mechanisms of isolation, allopatric speciation followed by range expansion better
explains the available data.
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Evolutionary Patterns in Pacific Amber Snails (Suecineidae):
the Relative Roles of Vicariance and Dispersal in Diversification and Island Biogeography
Brenden S. Holland and Robert H. Cowie
Center for Conservation Research & Training, Pacific Biosciences Research Center,
University of Hawai’i, 3050 Maile Way, Gilmore 408, Honolulu, HI 96822
bhoHand@hawaii.edu
Our work applies a molecular approach to investigate origins and patterns of biological
diversity in endemic Pacific land snails. In this study we seek to understand patterns of dispersal
and diversification in Pacific succineid snails, focusing on the diverse Hawaiian assemblage.
Preliminary results inferred from mitochondrial (COI, 16S) and nuclear (H3) markers suggest 1)
a complex colonization history in Hawai’i, including multiple primary colonization events from
non-Hawaiian sources; 2) examples of adherence to as well as violation of the progression rule
pattern of colonization from older to younger Hawaiian Islands; 3) evidence of colonization by
an endemic Hawaiian lineage into the South Pacific; and 4) unexpected patterns of inter-island
relationships. Many Pacific islands, including the Hawaiian archipelago, arose in situ as the
Pacific plate moves over a stationary hot spot. Thus, while local vicariant events within island
chains, such as fragmentation of large “super islands” into smaller ones by emergence and
submergence of land bridges resulting from the dynamic processes of formation, subsidence, and
erosion of islands as they move away from the hot spot, all play important short-term roles in
lineage isolation, dispersal is a key process in diversification of Pacific island succineid land
snails over the long-term. Molecular evidence suggests that long-distance oceanic dispersal and
colonization of the Hawaiian Islands has been rare but important, whereas inter-island dispersal
has been far more common, but has not always resulted in lineage splitting. Our results
demonstrate that oceanic dispersal should not be viewed as a trivial biogeographical
phenomenon and suggest that its importance has been underestimated.
What Can “Stems, Loops and Lollipops” Tell Us about Basommatophora?
Wallace Holznagel
Department of Biological Science, The University of Alabama, Tuscaloosa AL 35487
wholznag@bama.ua.edu
The Basommatophora is comprised of a conchologically, anatomically, and ecologically
heterogeneous assemblage of pulmonate gastropods. The monophyly of Basommatophora has
long been doubted and this view is substantiated indirectly by the markedly different
classification schemes and composition of the group presented by different systematists. The
presumed high degree of phylogenetic differentation among the taxa and the antiquity of the
group makes discovery of unambiguous homologous characters to infer phylogenetic
relationships difficult at best. The objective of this study was to test the monophyly of
Basommatophora and provide a preliminary hypothesis on the phylogenetic relationships of the
group using highly conservative cytoplasmic nuclear LSU ribosomal gene sequence
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Historic Pacific Grove Intertidal Nudibranch Collections are a Baseline with which to Test
Climate-related Species Range Change Hypotheses
Rebecca F. Johnson
Department of Invertebrate Zoology, California Academy of Sciences,
55 Music Concourse Dr., Golden Gate Park, San Francisco, CA 941 18,
and Department of Ecology and Evolutionary Biology,
University of California Santa Cruz, Santa Cruz, CA 95064
riohnson@calacademv.org
Recent studies, using historic surveys as baselines, have found pole-ward shifts in
species’ ranges that correspond to increased air and/or sea temperatures. Most of these studies
use observational data; annual butterfly counts, biological “inventories” and biodiversity
monitoring studies. These data are invaluable, but in most cases specimens were not collected,
therefore exactly what was seen can never be known. Although museum data has been
referenced in some of these studies and has been integral in documenting other recent
community changes, such as the timing of biological invasions, it is often discounted as baseline
data. Museum specimens are not always collected in a comprehensive, repeatable manner and
common organisms are not collected as often as rare organisms. Frank MacFarland studied the
nudibranch fauna of Monterey from 1901-1951. His notes, drawings and specimens are now part
of the California Academy of Sciences archives and collections. I am interested specifically in
the genus Cadlina. There are four species of Cadlina with overlapping ranges in the Monterey
Bay Region and over eighty specimens of Cadlina collected by MacFarland from Pacific Grove
are in our collection. This data set is comprehensive and repeatable and allows unique
comparison with new collections made following MacFarland’s notes. I will examine the
morphology and sequence mitochondrial DNA of MacFarland’s specimens and newly collected
specimens from the same localities. I will examine both collections to explore any changes in
species’ distributions in Monterey Bay. I will use the historic collection and new collections as
populations in a larger phylogeographic study.
Historical Phylogeny of Tahitian Partula
Younghun Jung, Taehwan Lee, John B. Burch and Diarmaid 6 Foighil
Museum of Zoology, The University of Michigan, Ann Arbor, Ml 48109-1079
diarmaid@umich.edu
Oceanic islands hold particular interest for both evolutionary and conservation biologists.
Native plants and animals evolved in isolation on these islands and provide detailed insights into
fundamental evolutionary processes. However, they characteristically lack well-developed
defensive mechanisms and are exceptionally vulnerable to introduced predators. Using DNA
analyses of museum specimens, we aim to reconstruct the evolutionary history of a critically
threatened radiation of land snails from Tahiti (French Polynesia). This Pacific island snail fauna
has recently been driven to the brink of extinction by an introduced predatory land snail. Our
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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museum samples predate the introduction of the predator and, in their DNA, they collectively
contain a genealogical record that we can use to revise the traditional shell-based taxonomy and
to determine how all these snails evolved on such a small, geologically young, island. Our
research will have practical value in helping to prioritize on-going conservation and
rehabilitation efforts. Collaborative agreements have been established with Zoological Society of
London personnel involved in overseeing captive Tahitian snail zoo populations and in saving
the last remnant wild populations. Our shared aim is to place the remnant wild and captive
populations into their proper evolutionary context: that of the previously intact fauna, by
obtaining DNA profiles of extant wild and captive populations that will be referenced with our
historical Tahitian database.
Species-level Phylogeny and Phylogeography of Conus : a Progress Report
Alan J. Kohn1, Christopher P. Meyer2 and Thomas F. Duda, Jr.3,4
'Department of Biology, University of Washington, Seattle, WA 98195
kohn@;u. washington.edu
2Florida Museum of Natural History, University of Florida, Gainesville, FL 3261 1
cmever@flmnh.ufl.edu
Department of Ecology and Evolutionary Biology,
University of Michigan, Ann Arbor, MI 48109
4Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Ancon, Republic of Panama
tfduda@umich.edu
Segments of two mitochondrial genes (16S rRNA and COI) of about 150 species of
Conus, or more than 25% of the recognized species in the genus, have now been sequenced. We
use these data to explore the degree of agreement between species distinguished by
morphological and molecular criteria, and to test prior hypotheses of species-level phylogeny
and phylogeography based on analyses of smaller samples. For Conus of the Indo-West Pacific
region, 16S genetic distances of species recognized on shell morphology generally confirm the
prior taxonomic decisions. Increased molecular sampling continues to support the early
(probably Late Eocene-Early Oligocene) divergence of two major lineages. The smaller of these,
thus far comprising only 16 species, is predominantly distributed in the Eastern Pacific and
Western Atlantic regions. The larger major clade, comprising all remaining species, is
predominantly Indo-West Pacific but includes representatives of all other geographic regions.
Recent analyses emphasizing Western Atlantic species suggest two subsequent radiations,
probably during the Miocene. One of these contains 12 Western Atlantic and 3 Eastern Pacific
species; the other, 2 Western Atlantic, one amphiatlantic, 5 Eastern Pacific, and a single Indo-
West Pacific species. The new results also support our prior hypotheses of monophyly of
molluscivorous Conus species and polyphyly of piscivorous species.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Frustrated Virgins and Reproductive Flexibility in the Sacoglossan Sea Slug Alderia:
How Hypodermic Insemination Affects Selfing and Speciation
Patrick J. Krug
California State University, Los Angeles, CA 90032
pkrug@calstatela.edu
Sacoglossan sea slugs live and feed on species-specific host algae, and their planktonic
larvae metamorphose in response to host-produced cues. Coevolution between slugs in the
genus Alderia and their host algae Vaucheria spp. has produced complex dispersal strategies and
cryptic speciation in Californian populations. I will discuss how hypodermic insemination leads
to self-fertilization and inappropriate sex between species. The southern Alderia sp. displays a
rare reproductive polymorphism, producing long-lived planktotrophic larvae or short-lived
lecithotrophic larvae. Virgin slugs, metamorphosed and reared in isolation, produced
unfertilized egg masses 5 days after reaching reproductive maturity; unfertilized clutches were
significantly larger than fertilized clutches of paired control slugs, suggesting mating costs
normally reduce fecundity. Virgin slugs began self-fertilizing 5 days after initial egg production,
a phenomenon only reported for 2 other opisthobranchs, both sacoglossans. Planktotrophic
virgins lowered their fecundity to control levels after selfing, whereas lecithotrophic virgins
produced more eggs per clutch whether unfertilized or self-fertilized, compared to mated
controls. Development mode and sexual history therefore interactively affect energy allocated to
reproduction. Selfing via accidental auto-injection may be a common consequence of
hypodermic insemination that has gone unnoticed due to sperm storage abilities of sacoglossans.
The sibling species of Alderia overlap without hybridizing, and cross-inseminations in the lab
normally yield no offspring, suggesting post-zygotic isolation has arisen. Hypodermic
insemination precludes most forms of pre-zygotic isolation seen in other organisms; I therefore
propose that in sacoglossans, sister species will occupy different algae in sympatry, achieving
reproductive isolation pleiotropically as a by-product of host choice behavior.
Mediterranean Land Snails and Wildfires
Esther Lachman
Department of Evolution, Systematics and Ecology,
The Alexander Silberman Institute of Life Sciences,
The Hebrew University of Jerusalem, Jerusalem, Israel
cookie@pob.huii.ac.ii
Wildfires in Mediterranean scrub in Israel occur mainly during the hot, dry summer,
when land snails are aestivating. Three common Mediterranean species were investigated
following a wildfire (in the Judean Hills, Israel). Euchondrus septemdentatus (inhabits shallow
soil pockets) was completely eradicated by the fire and has not re-colonized burnt areas to this
day (7 years post-fire). Levantina hierosolyma and Buliminus labrosus (crevice-dwellers)
survived the fire; their population dynamics were studied for five years in post-fire conditions.
Age composition differed between burnt and control plots in L. hierosolyma but not in B.
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labrosus. In the laboratory L. hierosolyma was found to be well adapted to the dry conditions
prevalent following wildfires. Its normothermic water loss rate (only 5% in 21 days) is the lowest
ever recorded for a Mediterranean land snail. When L. hierosolyma was exposed to combinations
of high temperatures (50-100°C) and time periods (5-120 minutes) in the laboratory it survived
exposures of up to 20 minutes at 60°C (14% survival) and 5 minutes at 75°C (100%). Longer
exposures at 75°C or higher temperatures (100°C) resulted in 100% mortality. Of the three
species, B. labrosus seems to be the least affected both by fire and post-fire conditions. L.
hierosolyma populations are affected by the fire, but laboratory results suggest they are at an
advantage in the dry conditions prevailing in the wake of wildfires. E. septemdentatus does not
survive and does not re-colonize burnt areas, even when reintroduced, indicating it is unable to
adapt to post-fire conditions.
Predator-prey Dynamics of Late Paleozoic Ecosystems:
A Case Study on the Role of Molluscs
Lindsey R. Leighton and Jennifer A. Sawyer
Department of Geological Sciences and Allison Center for Marine Research,
San Diego State University, San Diego, CA, 92182
leighton@geologv.sdsu.edu
Predation plays a major role in modem molluscan ecology but knowledge of the origins
of molluscan predator-prey dynamics in deep time remains limited. The majority of Early
Paleozoic gastropods and bivalves were restricted to nearshore habitats but during the
Carboniferous both classes radiated into “normal” marine systems, at which time molluscs were
exposed to a greater risk of predation. Previously, predators primarily attacked brachiopods.
How did the molluscan invasion of these ecosystems affect predator-prey dynamics and did
molluscs respond to this increase in predation? We examine several exceptionally well-
preserved assemblages from the Late Carboniferous of Texas that include diverse gastropods,
bivalves, and brachiopods, especially pleurotomariniid gastropods; mobile, shallow-infaunal,
bivalves; and productide brachiopods. Most taxa are similar in size and shell thickness, so
predators might be expected to prefer fleshier molluscs over brachiopods. Drilling predation was
restricted entirely to sedentary, epifaunal taxa, regardless of taxonomic affinity; these drillers
apparently were not as adept as some Holocene drillers at capturing mobile prey. Crushing
predators, however, left scars on gastropods (18% of specimens) much more frequently than
bivalves or brachiopods (8% each; difference is significant: chi-square test, p < 0.01). This
difference is either due to a greater rate of attacks on gastropods or greater success against other
taxa. Bivalve crushing frequency may be low because most bivalves were infaunal. The higher
frequency of scars on gastropods suggests that an increase in ornament in many gastropods
lineages, including the abundant pleurotomariniids, during the Late Carboniferous, may have
been an adaptive response to predation.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Sexual Selection and Mating Systems in the Genus Ariolimax
(Stylommatophora: Gastropoda)
Janet L. Leonard1, Jane A. Westfall2 and John S. Pearse1
’Joseph M. Long Marine Laboratory,
University of Califomia-Santa Cruz, Santa Cruz, CA 95060
i lleonar@ucsc.edu
department of Anatomy & Physiology, Kansas State University, Manhattan, KS 66506-5802
It has been hypothesized that where genital characters are taxonomically important at the
species level, sexual selection has been important. The taxonomy of the genus Ariolimax, the
banana slugs of North America, has been based on genital characters. Behavioral and
morphological studies of Ariolimax spp. provide substantial evidence for sexual selection.
Morphological studies show a previously undescribed genital polymorphism in Ariolimax
buttoni. Aphallate individuals of this species were previously termed Aphallarion buttoni
whereas euphallate forms had been synonymized with A. columbianus. This phally
polymorphism would reduce the number of individuals capable of mating as males in
populations of A. buttoni, thereby producing a skewed sex ratio. Behavioral data show that all
three species of the Meadarion subgenus (A. californicus, A. brachyphallus and A.
dolichophallus) , share a lengthy courtship behavior. A. brachyphallus may also show penial
stroking. A. stramineus of the subgenus Ariolimax has a very different courtship behavior
involving brief (20 m) mutual exploration with early penis eversion. Apophallation has been
observed in A. californicus and A. dolichophallus. Mating encounters involve a single 2h
simultaneously reciprocal intromission in A. dolichophallus; bouts of brief unilateral
intromissions in A. californicus and A. brachyphallus; a 2h simultaneously reciprocal
intromission preceeded by a brief unilateral intromission in A. stramineus and a > 24 h reciprocal
intromission in A. buttoni. Phally polymorphism, apophallation, lengthy and elaborate courtship
and the patterns of reciprocity observed provide circumstantial evidence for sexual selection in
this genus.
Hemocyanin and Molluscan Phylogeny: Outcomes, Restrictions and Perspectives
Bernhard Lieb and Jurgen Markl
Institute of Zoology, Johannes Gutenberg-University, D-55099 Mainz, Germany
lieb@uni-mainz.de: markl@uni-mainz.de
The phylogeny of the Mollusca is still debated at all systematic levels. It is therefore
justified to include as many useful phylogenetic characters as possible. We found that the blue
respiratory protein hemocyanin has some potential in this regard. Molluscan hemocyanin
subunits possess an evolutionary rate of ca. 10‘9, have a molecular mass of up to 400 kDa and are
encoded by up to 10,000 bp, thereby providing a statistically sound data set to trace molluscan
phylogeny. According to molecular clock calculations, this protein originated ca. 740 million
years ago, in the late Precambriam. After the separation of the molluscan classes, it was
apparently lost in the Caudofoveata, Scaphopoda and most bivalves, but retained in the
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 4 1
Polyplacophora, Gastropoda and Cephalopoda, and also in the protobranch bivalves. We found
that phylogenetic trees reconstructed from hemocyanin sequences are of only limited use to
unravel relationships between these four classes, but most efficient to trace phylogenies within
the latter. Examples for successful analyses range from the supraorder level via the family level
down to the genus level. In addition to sequence alignments, differences in gene architecture and
quaternary structure of this protein provide clues to elucidate key events of molluscan
phylogeny.
A Combined Analysis of the Phylogeny of Cephalopoda
Annie Lindgren and Frank Anderson
'Department of Evolution, Ecology and Organismal Biology,
The Ohio State University, Columbus, OH 43212
lindgren 1 l@osu.edu
Department of Zoology, Southern Illinois University, Carbondale, IL 62901
This study provides a comprehensive phylogenetic analysis of Cephalopoda using
molecular and morphological data. Regions of four molecular loci (nuclear 18S rRNA, 28S
rRNA, histone H3, and mitochondrial cytochrome c oxidase subunit I) were combined with 101
morphological characters to test interfamilial relationships of sixty cephalopod taxa, with
emphasis on the families within Decabrachia (“squids,” cuttles and their allies). Individual
molecular and combined data sets were analyzed using the direct optimization method (with
parsimony as the optimality criterion) and partitioned Bayesian methods. Monophyly of
Cephalopoda, Nautiloidea, Neocoleoidea (all extant cephalopods except nautiluses) and
Decabrachia was supported by most analyses; however, monophyly of Octobrachia (octopuses)
was falsified due to a lack of support for Cirroctopoda + Octopoda in some trees.
Vampyromorpha (vampire squids) was found to be sister to Decabrachia (rather than
Octobrachia) in both combined molecular and total evidence analyses. Within Decabrachia,
support was found for a relationship between the sepioid orders Idiosepiida, Sepiida (true
cuttles), Sepiolida and the teuthid family Loliginidae, rendering the order Teuthida polyphyletic.
We believe that the rooting of the neocoleoid portion of the tree, the phylogenetic position of
Vampyromorpha and the possible paraphyly of Octobrachia merit further investigation.
Extinction and the Evolutionary History of
Late Cretaceous and Early Cenozoic Veneroid bivalves
Rowan Lockwood
Department of Geology, The College of William and Mary,
PO Box 8795, Williamsburg, VA 23 1 87
rxlock@wm.edu
Although the causes of mass extinctions in the fossil record have been studied in detail,
recoveries have received little attention until recently. This study focuses on the effects of two
extinction events, the end-Cretaceous (K/T) and end-Eocene (E/O), on long-term patterns of
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Page 42
morphology and ecology in veneroid bivalves. Systematic and stratigraphic data were collected
for 140 subgenera of veneroids from the Late Cretaceous through Oligocene of North America
and Europe. Morphological data were collected for 1236 specimens representing 101 subgenera.
Extinction selectivity and preferential recovery were assessed with respect to morphology, and
by extension, burrowing ecology in these bivalves. Veneroids underwent a substantial extinction
at the K/T boundary, although diversity recovered to pre-extinction levels by the early Eocene.
Despite the severity of the K/T extinction, I found little evidence of morphological or ecological
selectivity. In contrast, the K/T rebound was significantly biased towards smaller taxa with more
elliptical shells and relatively deeper pallial sinuses (i.e., towards relatively deeper, faster
burro wers). The E/O event was considerably smaller and the recovery interval biased towards
larger veneroids. It is clear that the K/T, although short-lived in geological time, exerts a stronger
influence on diversity, morphology, and ecology in veneroids than the E/O event. The
morphological and ecological effects of the K/T are not tied to the extinction itself, but to the
recovery that follows. The K/T recovery initiates a trend towards deeper burrowing that helps to
establish veneroids as one of the most abundant and successful groups of modem marine
bivalves.
Dichostasiidae Yochelson, 1956, Permian to Holocene, Defined on Opercular and Shell
Characters (Vetigastropoda: Trochoidea)
James H. McLean
Natural History Museum of Los Angeles County, Los Angeles CA 90007
imclean@nhm.org
The family Dichostasiidae (based on the Permian genus Dichostasia Yochelson, 1956;
shell diameter 5 mm) has a circular aperture and fine lamellar sculpture, which led me to place
the genus among the living Liotiidae in 1981. The family Liotiidae is characterized by a circular
aperture and an operculum with a multispiral arrangement of calcareous beads on the outer
surface. Such opercula are not amenable to fossilization, which makes the early record of
Liotiidae open to question. Here I report on the operculum of a new living genus from the Indo-
Pacific sublittoral (no preserved bodies, maximum shell dimension 5 mm) with lamellar
sculpture that had initially suggested affinity to Liotiidae. That assignment is ruled out because
three shell specimens are known that have wedged-in, solid calcareous opercula. This operculum
has the inner surface conical with a fine multispiral pattern, and the outer surface with radial
rugosities and a deep central pit. A similar operculum has been described for the well-known and
broadly distributed Mesozoic genus Metriomphalus Cossmann, 1916. Metriomphalus has
previously been tentatively placed in the basal turbiniform family Colloniidae, but it has coarse
lamellar sculpture (instead of the dominant spiral sculpture of Colloniidae). Colloniidae differ in
having the peristome interrupted and the operculum becoming paucispiral on the inner surface of
the final volution. Details of the morphology of the mature lip of the new living genus closely
resemble those of the Permian genus Dichostasia. My hypothesis is that these three genera (the
new genus, Dichostasia, and Metriomphalus ) and certain other Mesozoic genera, for which the
operculum is yet unknown, can now be tentatively assigned to Dichostasiidae. The true Liotiidae
have details of shell sculpture that support a first appearance in the Late Cretaceous. There are
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Page 43
now three basal turbiniform families (Liotiidae, Colloniidae, Dichostasiidae), defined on
opercular and shell characters. Two of these families, the Liotiidae and Colloniidae, have a
similar rhipidoglossate radula (inner marginal teeth not enlarged), which can now be considered
to be plesiomorphic in the basal turbiniform families. The radula of Dichostasiidae as here
defined is unknown, but is probably of the plesiomorphic type.
Elemental Fingerprinting to Determine Larval Dispersal:
An Example Using Mytilid Mussels
Pat A. McMillan1, L. A. Levin1, B. J. Becker,1’2, F. J. Fodrie1 and L. Rasmussen1
'Scripps Institution of Oceanography, UCSD, La Jolla, CA 92093-0218
2Cabrillo National Monument, 1800 Cabrillo Memorial Drive, San Diego, CA 92106
pmcmiHan@ucsd.edu
Due to the small size of typical planktonic larvae, tracking larval movement has been a
difficult, if not impossible, task. Questions about larval transport focus largely on where larvae
go (dispersal) and where larvae come from (connectivity). To answer these questions, studies
addressing dispersal have included direct observations, mark-recapture experiments with tags
and dyes; while studies addressing connectivity have included physical modeling and elemental
tags. Technological advances have facilitated the use of elemental fingerprinting analysis to
evaluate origins and trajectories of some planktonic larvae. Spatial variability in trace elemental
characteristics of different coastal water masses is recorded in the geochemistry of biogenic
carbonates (e.g., otoliths, statoliths, shells). Since shells are deposited throughout planktonic
larval growth, they effectively record the environmental characteristics of different water
masses or habitats occupied by larvae during development. We are using trace element
fingerprinting methods to evaluate the spatial scale and strength of connectivity among Mytilus
galloprovincialis and M. californianus populations in southern California. Our approach
involves laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to resolve
variation in larval shell chemistry that reflects recruit origins and temporal patterns of larval
transport. We are also testing realized population connectivity determined from trace elemental
analysis of recruit origins against a priori predictions based on circulation and metapopulation
models. The information obtained regarding source populations and connectivity will increase
our understanding of larval transport and retention as well as marine metapopulation dynamics,
ultimately aiding in the conservation of coastal resources and design of marine protected areas.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Evolution of Anatomy and Morphology in Miniaturized
Marine Snails (Neogastropoda: Columbellidae)
Marta J. deMaintenon
Marine Science Department, University of Hawai’i, Hilo, HI 96720
demainte@hawaii.e<iu
The evolution of small body size has important consequences for organismal ecology and
physiology, and may be associated with the episodes of origination and diversification that have
led to many higher taxa. Preliminary research indicates that several investigated species of small
Indo-Pacific columbellid marine snails are miniaturized; they are similar in gross anatomy to
much larger species but have proportionately smaller cell sizes. One question remaining to be
addressed is what anatomical and morphological changes have occurred in addition to
miniaturization that might be associated with the transition to small size. Anatomical reduction is
commonly seen in small-bodied species, and may be an important prerequisite for the origin of
novel body plans. In this ongoing study, anatomical data corroborated with species level
phylogenetic hypotheses indicate that miniaturized columbellids are in some respects
anatomically simplified in addition to being miniaturized; they lack opercula, the osphradium is
monopectinate rather than bipectinate, and certain conchological characteristics are reduced in
size. These characteristics are not restricted to the smallest species however, and may be
associated with factors other than size reduction.
Do More Tissues Automatically Equate to a Heavier Breather?
Claire-Louise Martin
University of New England, National Marine Science Centre,
P.O. Box J321, Coffs Harbour, New South Wales, 2450, Australia
cmartin@nmsc.edu.au
The fissurellids (Mollusca: Vetigastropoda) are bilaterally symmetrical. They are
commonly known as keyhole or slit limpets due to a hole or slit either at the apex or anterior
margin. The mantle cavity of fissurellids contains paired ctenidia, osphradia and hypobranchial
glands. Interestingly, the fissurellids are the only gastropods in which all mantle cavity organs
are paired and symmetrical. Like most vetigastropods, fissurellids also have paired auricles,
gonads, kidneys and the digestive tract and nervous system are crossed. Symmetrically paired
organs are not found in any of the other groups of uncoiled limpet-shaped gastropods. Even the
sister group to the gastropods, patellogastropods (true limpets), have asymmetrical organs with
highly modified mantle cavity arrangements. Not only is the plesiomorphic mantle cavity
arrangement in fissurellids unusual for gastropods, there is also a great size variance within the
group, with the larger species having extended mantle and foot tissue. Despite the increase in
surface area of tissue a deepening of the mantle cavity has not occurred. As a result of this the
paired ctenidia do not appear to have enlarged and the question of how these animals are
reaching their required oxygen quota arises. This research aims to test hypotheses about the
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Page 45
popularly perceived notions regarding the inefficient nature of a symmetrical mantle cavity and
to determine if the foot or mantle are being utilised as secondary respiratory surfaces.
Changes in the Mussel Community of Ohio Brush Creek
i i a i
Stephen F. Matter , Francisco J. Borrero ’ , and Chris Bedel
'Cincinnati Museum Center at Union Terminal, 1301 Western Ave., Cincinnati, OH 45203
Cincinnati Country Day School, 6905 Given Rd., Cincinnati, OH 45243
boirerof@countAdav.net
We evaluated the status of the mussel community of Ohio Brush Creek and its tributaries in
southeastern Ohio over a 17 year period. This stream has harbored one of the most diverse
mussel communities in the region, with 39 of the 76 species recorded for the entire state of Ohio.
Species richness increased to 23 in 2004, from 16 and 20 species found in 1996 and 1987,
respectively. Despite the increase in species number, the abundance of live and freshly dead
shells declined, particularly for abundant species. Community structure has changed from one
dominated by a few abundant species to a more evenly distributed community composed of a
greater number of species with lower abundances. More detailed study of the mussel community
of Ohio Brush Creek is warranted. Ongoing mark-recapture work combined with size class
structure will provide information to assess whether changes in abundance are due to adult
survivorship, recruitment, or are simply a reflection of variability in population size and
sampling. In addition, analysis of the health of fish host populations and mapping of substratum
types available to mussels will allow ascertaining potential factors affecting the mussel
community. At this time, large scale factors, rather than localized disturbance appear to be
responsible for the observed changes in diversity and abundance of mussels.
Mating and Egg-laying Behavior in Aplysia: Pheromones and Neural Mechanisms
Earl Mayeri
Department of Physiology, University of California, San Francisco, San Francisco, CA 94143
inaveri@itsa.ucsf.edu
In the marine mollusk, Aplysia californica , there is a sequence of behaviors that occurs
during mating and egg laying that lasts for up to several hours. Pheromones appear to play a
critical role in initiating and coordinating the behaviors between individuals. Within each
individual, the behavioral sequence is initiated by a chemical stimulus - probably a contact
pheromone - located in an egg mass laid by others. In the central nervous system, this stimulus
triggers release of neuropeptides from a defined group of neuroendocrine cells and other neurons
coupled to them. The actions of the neuropeptides within the central nervous system and on
peripheral organs serve to orchestrate the behavioral sequence, which in these hermaphrodites
consists of mating as a female, laying eggs, and then mating as a male.
The release of neuropeptides corresponds to what ethologists long ago speculated to be
an “innate releasing mechanism.” The innate releasing mechanism is triggered by a sign
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Page 46
stimulus - in this case a contact pheromone in the egg mass. Many features of the reproductive
behavior of Aplysia are also features of instinctive, reproductive behavior in other mollusks and
other animals, including humans. In many of these cases it seems likely that there is an innate
releasing mechanism that also involves the release of neuropeptides from defined neural circuits.
The neuropeptides act on target neurons within the central nervous system to modulate electrical
signaling for minutes or hours, and thus regulate aspects of the behavior.
Interpreting Life’s History Through the Lens of the Present:
Accounting for Variability in Biogeographic Inference
Christopher P. Meyer
Florida Museum of Natural History, University of Florida, Gainesville, FL 3261 1
cmever@flmnh.ufl.edu
Phylogenies and distributions of extant species are often used to test competing historical
biogeographic scenarios and elucidate diversification processes. As such, inferences are only as
good as the robustness of the trees and the accuracy of the ranges. What is more, both datasets
are inherently problematic because of their temporal variability: phylogenies based on sequence
data must account for coalescent processes and thoroughness of sampling, while biogeographic
ranges are dynamic with range expansions via dispersal and contractions leading to relictualism
and ultimately extinction. When interpreting historical events from present perspectives, we must
be certain to check assumptions, accommodate this variation, and have a clear understanding of
null hypotheses. Should we expect sister pairs to behave equally on the same evolutionary stage
if they have equivalent attributes? How much can variability affect resulting patterns? Given a
well-supported phylogeny and good range data, how many alternative biogeographic scenarios
are possible? Are probable? How do we take account of the coalescent process in polarizing
biogeographic events? Are conclusions vulnerable based on incomplete sampling? What
additional information can increase confidence in explanations? I will address each of these
points using data from various molluscan groups including cowries, cones, limpets, and
turbinids.
Mexican Holospirinae in Review (Gastropoda: Urocoptidae)
Elizabeth L. Mihalcik1 and F. G. Thompson2
'Department of Arts and Sciences, Bainbridge College, Bainbridge GA 39819
emihalcik@bainbridee.edu
2Florida Museum of Natural History, University of Florida, Gainesville, FL, 3271 1
The subfamily Holospirinae range from the southwestern states of Arizona, New Mexico
and Texas to southern Mexico. Within the area of Puebla and immediately adjacent states, 28
species are recognized of which 14 are new. Twelve species groups of Holospira are recognized
within the subgenus Holospira within the study area. Within the subgenus Stalactella, five
species are recognized. The genus Holospira is much more widespread then Stalactella which is
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Page 47
confined to Puebla and Oaxaca. They are found in submesic and xeric habitats of limestone or
dolomite substrata. Colonies of snails are limited to proximal outcrops. Prior literature poorly
described morphological features for species identification. This study uses shell morphology
including internal lamellae, radula, and soft anatomy to differentiate between species-groups.
The internal lamellae serve as a predator barrier and characterize each group. They are
represented typically by four lamellae: basal, columellar, palatal and parietal. Some species-
groups like H. melea, H. hogeana, H. fortisculpta, H. scololaema and H. haploplax have a
reduced number of lamellae. The species-groups that have the characteristic four internal
lamellae vary greatly in shape between them. The four lamellae stage is considered to be the
ancestral condition and evolution of some groups occurred through loss of lamellae. This
statement is based on the oldest known fossil of Holospira as well as the general occurrence of
four lamellae throughout the range of the genus.
Two New Northeastern Pacific Nudibranchs
Sandra Millen
Department of Zoology, University of British Columbia, Vancouver, B.C., V6T 1Z4, Canada
millenfg'zoology.ubc.ca
The northern Pacific coast of North America continues to reveal new species of
nudibranchs in the subtidal zone. A deep-water dredge off the coast of Washington state brought
up a new dorid from a depth of 146 m. It was photographed live and obligingly laid an egg mass.
Internal investigation revealed it was a new species of the uncommon genus Baptodoris (Family
Dorididae). The internal anatomy with SEM’s of the reproductive spines is shown.
The cold winter fjord waters of British Columbia revealed to divers a new species of
Janolus (Family Zephyrinidae) crawling on the muddy bottoms. Although this species has been
photographed and collected a number of times, its spawn and food' remain unknown. The
anatomy of this species is shown with special emphasis on their elaborate jaws designed to nip
bryozoans. The systematic relationships of these two new species are discussed.
Pondering the Purpose of Precarious Postures:
The Effect of Littorine Snail Shell Orientation on Body Temperature
Luke P. Miller
Hopkins Marine Station, Stanford University, Ocean View Blvd, Pacific Grove, CA 93950
millerlp@stanford.edu
Littorine snails living high in the intertidal zone must endure some of the longest aerial
exposures and hottest temperatures of any marine organism. During periods of calm sea
conditions a snail may be out of the water for days on end. The high temperatures and prolonged
periods of desiccation experienced by these snails could lead to physiological stress or death. On
the west coast of North America, several of the Littorina species have been observed to carry out
a unique behavior under particularly stressful circumstances. Snails will glue the lip of the shell
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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to the rock substrate and lift the rest of the shell away from the rock. This leaves the entire snail
perched on the lip of shell, which minimizes conduction of heat from the hot rocks and
maximizes convective cooling with the surrounding air. Shells of four species of northeastern
Pacific Littorina were used to create models to measure shell temperatures under hot conditions
in the lab and in the field. When littorine shells are perched on the lip of the shell, the shell
temperature can stay 2 to 5 degrees C cooler than the same shell sitting down on the rock. These
lower shell temperatures may be important for minimizing the intensity and duration of heat
stress, as well as lowering the rate of evaporation. The benefits and potential liabilities of this
behavior will be discussed.
Sexual Conflict and the Rise of Alternative
Reproductive Tactics in the Banana Slug, Ariolimax dolichophallus
Brooke L.W. Miller
Department of Ecology and Evolutionary Biology,
University of California at Santa Cruz, Santa Cruz, CA 95064
milier@biology.ucsc.edu
Banana slugs of the genus Ariolimax are simultaneous hermaphrodites, like all pulmonate
slugs. They are unusual, however, in that sometimes after mating one slug will chew the penis
off of its mating partner. This bizarre behavior, termed apophallation, is often reciprocal, where
both slugs lose a penis at the end of the mating encounter. The penis does not grow back. In the
past, the main explanation for this behavior was that it was a maladaptive consequence of
selection favoring a large penis. Here I report high frequencies of aphallate slugs in the field,
which suggest a potential for strong selective pressure caused by apophallation, making non-
adaptive hypotheses unlikely. I also introduce a game theoretical approach for examining
apophallation and the potential invasion of alternative behavioral strategies, with evidence from
lab reared animals.
Quantitative and Qualitative Variation of the Protein Content of the Embryos of Crepidula
navicula (Caenogastropoda: Calyptraeidae) During Intracapsular Development
Patricia Miloslavich and Elizabeth Huck
Universidad Simon Bolivar, Departamento de Estudios Ambientales,
Laboratorio de Biologia Marina, Caracas, Venezuela
pmilos@usb.ve
Hatching size and mode determine in great measure the chance of survival in young
caenogastropods. These are determined by the energy available during embryonic development,
which is related to the amount and type of proteins in the embryo. Egg capsules of Crepidula
navicula contain 1-6 eggs, all of which develop to the hatching stage as pediveligers, although,
cannibalism among sibling embryos has been observed. To determine how the proteins are being
used by the embryo during development as well as if there is a significant increase of their
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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protein content confirming the importance of cannibalism, we determined the protein content of
the developing embryos of C. navicula at 9 diferent stages of development as well as the
electrophoretic pattern of the proteins at these same stages. We found 4.83±0.54 Mg protein/egg,
a value that decreases significantly to the trochophore stage to 2.63±0.66 Mg, increases to the
veliger I stage to 5.62±0.75 Mg/veliger and then decreases at the hatching stage to 3.71±0.74
Mg/hatchling (Kruskal Wallis followed by Tukey multiple comparisons, p<0.001).
The electrophoretic pattern showed that eggs and embryos are characterized mostly by
high molecular weight proteins (88-150 KDa), two of 16 and 18 KDa respectively and some
minoritarian proteins of 44 and 53 KDa. At hatching, most of these proteins have been consumed
and transformed into lower molecular weight proteins, and many minoritarian bands above 70
KDa were observed in pediveligers and at the prehatching stage.
Mapping Marine Invertebrate Biodiversity Hotspots
in the Indo-Pacific Ocean Using GIS
Fabio Moretzsohn1, 2 and Myra K.K. McShane2
'Center for Coastal Studies, Texas A&M University-Corpus Christi,
6300 Ocean Drive, NRC 3208, Corpus Christi, TX 78412
mollusca@gmaii.com
2Pacific Biological Survey, Bishop Museum, Honolulu, HI
Under the auspices of the MacArthur Foundation, the Pacific Biological Survey, Bishop
Museum studied the distribution of marine invertebrates in the Indo-Pacific as an aid to set
policies and priorities for conservation of marine organisms. The taxonomic coverage included
all 794 hermatypic coral species, 1,166 mollusks, and 289 crustaceans, totaling 2,249 species in
the Indo-Pacific. Distributional data were gathered from museum collections and taxonomic
literature and georeferenced to plot species distributions on maps using ESRI ArcGIS 8.3.
Composite maps of biodiversity for each family revealed patterns of species richness that were
concordant with a few exceptions. The region between the Philippines, the Malay Peninsula and
New Guinea has the highest diversity of corals and is known as the “coral triangle.” From this
center of diversity in the tropics there are latitudinal and longitudinal gradients, decreasing
rapidly with distance from the center. Mollusks and crustaceans studied showed similar patterns
of diversity, although the region of highest diversity was slightly wider than the coral triangle.
Data on threats to coral reefs were used to rank the biodiversity hotspots according to species
richness and threat risk, to preserve the largest number of species concentrated in small areas.
The top biodiversity hotspots are: coral triangle, Vietnam, Thailand, Micronesia, Fiji, Okinawa,
Sri Lanka, Seychelles, Madagascar, Comoro and Mascarene Islands, Tanzania, and Red Sea,
among others. Many of these areas were recently affected by strong earthquakes and tsunamis,
and biodiversity may be under greater danger than previously reported.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Biodiversity of Marine Molluscs of the Gulf of Mexico
Fabio Moretzsohn and John W. Tunnell, Jr.
Center for Coastal Studies/Harte Research Institute, Texas A&M, University-Corpus Christi, 6300 Ocean Drive,
NRC3208, Corpus Christi, TX 78412
moliusca@gmail.com
The Harte Research Institute for Gulf of Mexico Studies at Texas A&M University-
Corpus Christi is sponsoring a 50-year update of “Bulletin 89.” This volume, Gulf of Mexico-Its
Origin, Waters, and Marine Life, on the state-of-the-science in the Gulf of Mexico (GOM),
published in 1954, is still used as a major historical reference for the region. The updated
version will be published in 2006 in five volumes, with one volume dedicated to the Biota of the
GOM. A team of more than 100 expert taxonomists from six countries (including Cuba, Mexico
and the USA) was assembled to compile the biodiversity of the GOM. This endeavor represents
the largest in-depth taxonomic treatment of the whole biota of a large marine ecosystem of this
scale. The current known diversity of molluscs alone is almost the same as the known biota of
the region 50 years ago, with about 2,700 molluscan species documented in the GOM. Although
still preliminary, the diversity of molluscs in the GOM can be broken down as follows:
Aplacophora-13 species (with seven new species being described); Polyplacophora-39 species;
Gastropoda-circa 1,900 species; Cephalopoda-24 species; Bivalvia-circa 670 species; and
Scaphopoda-41 species. New records (range extensions), recent descriptions of new species and
the inclusion of micromolluscs and deep-water species account for the sharp increase in the
known diversity in the region.
Identification of Host Specific Genes in a Sepiolid Squid/ Vibrio Mutualism
Michele K. Nishiguchi
Department of Biology, New Mexico State University,
Box 30001, MSC 3 AF, Las Cruces, NM 88003
nish@nmsu.edu
Bioluminescent bacteria from the genus Vibrio exist in a diverse number of
environmental habitats. They can be found as saprophytes, symbionts of leiognathid fishes and
sepiolid squids, or free-living in natural seawater. The mutualistic associations between V
fischeri and the sepiolid squids Euprymna tasmanica and E. scolopes (squids endemic to
Australia and the Hawaiian archipelago, respectively) are host specific, with V fischeri strains
highly adapted to squids found within their same habitat. While the development and
maintenance of this mutualism has been well studied from the host’s perspective, V. fischeri gene
expression within the light organ has not been characterized. To determine this, I have produced
libraries of V fischeri genes expressed exclusively in the host light organ or in seawater using
Selective Capture of Transcribed Sequences (SCOTS), a procedure that relies on a series of
normalization and enrichment hybridizations to identify differentially expressed genes. Genes
expressed in the light organ include multiple chaperones, fermentation enzymes, amino acid
uptake and biosynthesis proteins, pH homeostasis, and adhesion. Seawater-expressed genes
include those for biosynthesis of a number of compounds, aerobic respiration, and multiple ion
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 5 1
channel pumps. Comparisons of these data support the notion that the light organ is an anoxic
environment in which host-derived nutrients are supplied to V. fischeri. To my knowledge, this
is the first time bacterial gene expression has been examined between two natural environments
in an environmentally transmitted mollusc/bacterial symbiosis.
Using Nested Clade Analyses for Determining Species Boundaries in Three Indo-West
Pacific Euprymna Species and their Luminescent Symbionts
Michele K. Nishiguchi
Department of Biology, New Mexico State University,
Box 30001, MSC3AF, Las Cruces, NM 88003
nish@nirisu.edu
The sepiolid squid- Vibrio mutualism is an excellent system for examining mechanisms of
cospeciation and host tracking patterns among a wide variety of symbiotic squid species.
Currently, I am using genetic diversity and nested clade analyses to examine the variation
between three allopatric Euprymna squid species: Euprymna s colopes (Hawai’i), E. hyllebergi
(Thailand), and E. tasmanica (Australia). Using three mitochondrial loci (cytochrome c oxidase
subunit I, 12S, and 16S rRNA) for host squid species, and the glyceraldehyde phosphate
dehydrogenase {gapA ) locus for Vibrio symbionts, I have determined the genetic relatedness of
these partners in the Indo-west Pacific as well as the phylogeography and fixation indices
between populations of both squids and symbionts. Patterns of host specificity are predominant
among symbiont genotypes and their phylogeography, but there is also some evidence of strain
variation, which might preclude that squid populations are not the only driving force for
selection of symbiont speciation.
A New Species of Sinezona from the Canary Islands
(Gastropoda: Vetigastropoda: Scissurellidae)
Jaya Nolt
Santa Barbara Museum of Natural History, 2559 Puesta del Sol Rd, Santa Barbara, CA 93101
iavanolt@vahoo.com
A new Sinezona species from the Canary Islands is compared to similar species from the
European area [S. cingulata (O.G. Costa, 1861)] and the Caribbean [S. confusa (Rolan, 1996)].
Since internal anatomy is still relatively unknown for described species of Sinezona Finlay,
1926, this paper will focus on shell morphology. Due to their small size, scanning electron
microscope imaging is ideal to show shell characteristics. Images of both species were taken
using a Zeiss EVO 40 XVP. Apertural, apical and umbilical views were imaged. Shell
sculpture, foramen, selenizone and protoconch characteristics were analyzed and will be
discussed. This study is supported by a grant from NSF (MRI 0420726).
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Revised Generic Placement of Transenelia humilis to Nuiricola
Jaya Nolt
Santa Barbara Museum of Natural History, 2559 Puesta del Sol Rd, Santa Barbara, CA 93105
avanolt@vahoo.com
The generic status of Transenelia humilis (Carpenter, 1857) has been in question since
1982. Comparisons are made with Nutricola [type species N. tantilla (Gould, 1853)] from the
Panamic Province and Transennella [type species T. conradina Dali, 1884] from the western
Atlantic. Scanning electron micrographs are presented. Shell morphology including pallial sinus,
anterior lateral teeth, lunule, escutcheon and amphidetic placement of the ligament were
analyzed. Observations of asynchronous brooding in N. humilis are documented.
Gametogenesis and Size at Reproductive Maturity of
Melongena melongena (Linnaeus, 1758) (Caenogastropoda: Melongenidae)
at Golfete de Cuare, Venezuela
Nicida Noriega and Patricia Miloslavich
Universidad Simon Bolivar, Departamento de Estudios Ambientales,
Laboratorio de Biologla Marina, Caracas, Venezuela
nicidanoriega@,gmai i .com
Melongena melongena is subject to an intense fisheries exploitation at Golfete de Cuare
and does not have any regulation controlling its catch. To determine the minimal catchable size
and the reproductive season, we studied the gametogenesis of this species monthly between April
2002-March 2003 and determined size at sexual maturity. Gonads were studied by classic
histological method^ and the following stages were observed: early active, late active, maturity,
gamete release and resorbtion. In the early active stage, previtelogenic oogonia and oocytes were
observed, these were closely connected to the accompanying cells and the epithelium. In the late
active stage, the oocoytes are still growing near the follicle wall, attached to it by a peduncle. At
the maturity stage, the oocytes detach from the follicle wall and migrate to the lumen. During
gamete release and resorbtion, few oocytes can be observed in the gonad and some yellow bodies
or mastrocytes are observed. Size of mature oocytes varied between 180-200 pm in length.
Gamete release of females occured in July, December and March, with three active gametogenic
periods. Gonad recovery was inmediate with no resting periods. No synchrony was observed
between female and male gametogenic cycles. Copulation probably occurs 1-2 months before
egg laying. Minimal size at sexual maturity was 5.1 cm in shell length for females and 5.8 cm for
males, and the size of maturity for 50% of the individuals was 6.8 cm for females and 6.6 for
males. We suggest these as the minimal catchable size at Cuare.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 53
The Relationship Between Body Size, Growth, and Egg Production in the Hermaphroditic
Freshwater Snail, Helisoma trivolvis
Cynthia G. Norton and Jennifer M. Bronson
Department of Biology, College of St. Catherine, St. Paul, MN, 55105
cgnortonfastkate.edu
Among several other factors, body size has been found to influence gender role in several
species of hermaphroditic snail, since when body size and egg production are linked, it is
expected that larger individuals should act as females and smaller individuals as males. We
tested whether such a relationship between body size and egg production exists in Helisoma
trivolvis, a freshwater hermaphroditic pulmonate. We isolated 50 H. trivolvis from a laboratory
population, measured shell diameter, and monitored egg production for seven weeks. We found a
positive relationship between body size and total number of eggs produced, as well as body size
and number of eggs per egg mass. Since body size is linked to fecundity in this species, the
relative size of snails should determine, at least in part, which individual acts as male and which
as female during copulation. However, the relationship between body size and egg production is
not nearly as strong as it is in other snail genera. Other factors such as age, genotype, and
previous experience may be important in determining egg laying capacity and therefore gender
choice, and may explain the occurrence of simultaneous reciprocal copulation in this genus, but
not others. In addition, we found a negative relationship between growth during this period and
egg production. This relationship has been found in other pulmonates, and is evidence of
resource allocation tradeoffs.
The Diversification of the Family Enidae in Turkey: an Evolutionary Perspective
Ay din Orstan1 and M. Zeki Yildirim2
'Section of Mollusks, Carnegie Museum of Natural History,
4400 Forbes Ave., Pittsburgh, PA, 15213
pulmonate@earthlink.net
2Siileyman Demirel Universitesi, Burdur E itim Faktiltesi, 15100, Burdur, Turkey
The range of the pulmonate family Enidae, with about 70 genera, extends from Japan
across Asia, Middle East, Europe and North Africa to the Azores. Twenty-four genera with close
to 90 species have been recorded from Turkey, indicating that a significant diversification of the
family has taken place on the land masses that now comprise Turkey. Our ongoing revisions of
the Turkish taxa are aimed at developing a more accurate phylogeny and a better understanding
of the evolutionary history of these snails. Several conchologically similar genera found in
Turkey differ anatomically (for example, Mastus, Paramastus , Borlumastus, Ena, Merdigera,
Megalena ), while many congeneric species are difficult to distinguish anatomically (for example,
Mastus species, Jaminia species). When anatomical and conchological characteristics are taken
together some generalizations are beginning to emerge. We are also creating high resolution
distribution maps that are expected to offer a better understanding of not only the current ecology
of these snails but also the past speciation events.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Phenotypic Plasticity in Molluscs
Dianna K. Padilla
Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 1 1794
padilia@life.bio.sunysb.edu
Phenotypic plasticity, or the ability of a single genotype to produce multiple phenotypes,
has recently gained the attention of not only evolutionary biologists, but also of ecologists and
behaviorists. Molluscs have proven to be an important system for studies of plasticity, and
molluscs now provide us with some of the best examples of inducible offenses, defenses, flexible
life histories as well as community wide ecological impacts termed trait mediated interactions
and indirect interactions. Studies on molluscs are often justified because, due to the extensive
fossil record of many molluscan groups, current studies can give us insight into both patterns and
processes that were historically important. I examine the types of plasticity that have been
studied in molluscs, believed ecological and evolutionary implications and consequences of these
plasticities, and where we should look for additional plasticities that have yet to be studied. I
consider which of these types of plasticities could be detectable in the fossil record, and if there
are processes that could be inferred from known plasticities that might be preserved in fossil
assemblages.
Identifying the Pupilloids Gastrocopta pentodon and G. tappaniana
on the Delmarva Peninsula, Eastern USA
Timothy A. Pearce
Carnegie Museum of Natural History, 4400 Forbes Ave., Pittsburgh, Pennsylvania 15213
PearceT@CamegieMNH.org
The North American pupilloid land snails Gastrocopta pentodon (Say, 1822) and G.
tappaniana (C.B. Adams, 1842) have similar looking shells, and although G. pentodon tends to
have a smaller, narrower, and less conical shell, in practice separating the two forms is difficult.
While some workers cite habitat differences as evidence that the two forms are valid species (G.
tappaniana occurring in moister habitats), an alternate hypothesis considers the possibility of one
species whose shell morphology is influenced by the moistness of the environment. Vanatta &
Pilsbry (1906, Nautilus 19: 121-128) illustrated 53 shells of the two forms but the differences
between the forms are subtle. Discriminant function analysis of measurements from their
illustrations gave a function that classified their shells 94% correctly. Applying this function to
577 shells from 129 localities throughout the Delmarva Peninsula, Eastern USA, revealed that
both forms occur on Delmarva, with 74% of the specimens classified as G. pentodon. Moisture
associations of plants at the sites address whether the two forms differ in the moistness of their
habitats. Examination of specimens at sites where both forms co-occurred addresses whether
they appear to be separate species or environmentally influenced forms of one species.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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A Summary of the International Partulid Conservation Programme
and its Significance for Other Group-level Managed Species
Paul Pearce-Kelly
Zoological Society of London, Regent's Park, London, NW1 4RY UK
ppk@zsl.org
The remarkable contribution that Partulid snail studies have made to the field of
evolutionary genetics is well-documented. Likewise their tragic extinction crisis has provided a
classic case-study of invasive predator-induced mass species loss. The resultant International
Partulid Conservation Programme has provided the conservation community with a model for
developing population management techniques and tools for species requiring management at
the group (i.e. life-stage based) rather than at the individual level. This paper summarises the key
elements of the Partulid management programme and discusses its wider significance for other
group-level managed species.
Phylogeography of Banana Slugs ( Ariolimax spp.)
(Gastropoda: Stylommatophora: Arionidae)
John S. Pearse , Karin Breugelmans , Thierry Backeljau and Janet L. Leonard
1 University of California, Santa Cruz, 1 1 56 High Street, Santa Cruz, CA 95064
pearse@biology.ucsc.edu
2 Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium
Pilsbry (1948) recognized 5 taxa of banana slugs based on differences in genital
morphology : Ariolimax {Ariolimax) columbianus columbianus, A. (A.) c. stramineus, A.
( Meadarion ) californicus californicus, A. (M) c. br achy phallus, and A. (M) dolichophallus. His
columbianus taxon occurred from central California to SE Alaska, stramineus from central
California to southern California, and the Meadarion taxa were all separate populations on the
San Francisco Peninsula. Our analyses of 3 mitochondrial markers (C01, 16S, and CytB) are
largely congruent with Pilsbry’s taxonomy except: (1) Pilsbry’s columbianus consists of two
clades, one that occurs along the coast from Humboldt Co. to SE Alaska and a second that occurs
farther south to northern Monterey Co.; we propose to resurrect the name buttoni (Pilsbry &
Vanatta, 1896) for this second clade. (2) Clades within Meadarion are only weakly distinguished
despite morphological differences. Moreover, brachyphallus has three distinct populations:
northern San Francisco Peninsula, Monterey Peninsula, and Cambria. (3) There are 2
undescribed clades, one within Meadarion on Fremont Peak, on the Monterey-San Benito county
boundary, and the other within Ariolimax (subgenus) on Mount Palomar, San Diego County. The
distribution of these clades resembles that of other slow-moving terrestrial organisms (e.g.,
salamanders), indicating similar vicariant processes. Moreover, differences in genital
morphology and mating behavior among the Meadarion clades strongly indicate rapid evolution
due to sexual selection.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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A Phylogenetic Study of the Invasive Land Snail Species
Praticolella griseola (Gastropoda: Polygyridae)
Kathryn E. Perez
Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, 35487
perez005@bama.ua.edu
Praticolella griseola was described by Pfeiffer in 1841 from Veracruz, Mexico. This
species is thought to live in Mexico and Central America with a disjunct population in South
Texas, and invasive populations in the Southeastern US. Historical taxonomy in the genus
Praticolella is primarily based on shell morphology. Molecular phylogenetic work on the genus
Praticolella has revealed several distinctive lineages within Praticolella griseola. Molecular and
morphometric data indicates that there are four species currently masquerading under the name
“ Praticolella griseola .” This includes three invasive species, one being true Praticolella
griseola , and two other unnamed lineages which are invasive in the southeastern US, and one
unnamed species native to South Texas.
Determinate Growth and Variable Size at Maturity in
the Marine Gastropod Amphissa Columbiana (Columbellidae)
Bruno Pemet
Department of Biological Sciences,Califomia State University, 1250 Bellflower Blvd., Long Beach, CA 90840
bpeniet@csulb.edu
Amphissa Columbiana from the intertidal zone of San Juan Island, Washington typically
have either shells with thin, delicate apertural lips, or shells with thick, robust lips. In the
laboratory, thin-lipped snails grew rapidly, but were not sexually mature, while thick-lipped
snails grew very slowly or not at all, and were sexually mature. These observations are
consistent with the hypothesis that A. Columbiana displays determinate growth, as has been
inferred for many columbellids solely on the basis of intraspecific variation in shell form. Sizes
of mature snails varied widely, with the largest individuals weighing 4.5 times as much as the
smallest (wet tissue weight). I tested the hypothesis that maturation and associated shell
thickening are phenotypically plastic responses to the presence of shell-crushing predators.
Exposure to effluent from the crab Cancer productus in the laboratory had no effect on shell
form or relative shell weight (an index of shell thickness), suggesting that this is not the case.
Sparse data show that A. columbiana from subtidal habitats may mature at larger sizes than
intertidal conspecifics. Because these snails have long-lived feeding larvae, intertidal and
subtidal populations are likely genetically continuous; it thus seems probable that environmental
factors play a significant role in explaining among-habitat, and perhaps within-habitat, variation
in size at maturation in this species.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Detection of Alternative Stable States in Extant Communities:
the Need for a Historical Perspective
Peter S. Petraitis
Department of Biology, University of Pennsylvania, Philadelphia, PA 19104-6017
ppetrait@sas.upenn.edu
The possibility that different assemblages of species may exist as alternative stable states
remains largely unexplored by experimental ecologists because of a variety of conceptual and
experimental problems. In particular, ecologists often ignore the distinction between the
processes that initiate the switch among alternative states and the positive-feedback processes
that maintain those states. This is analogous to the problem of assessing the causes for the origin
versus maintenance of traits in the fossil record. Appropriate experimental designs for detecting
alternative states in extant systems are discussed. It is clear that good experimental designs must
account for successional (i.e., historical) changes in community structure. Suggestions for
improving experimental tests are proposed and unresolved issues are highlighted.
A Preliminary Review of California Fossil Austrotrophon and Forreria
(Gastropoda: Muricidae: Ocenebrinae)
Charles L. Powell, II
U.S. Geological Survey, MS 975, 345 Middlefield Rd., Menlo Park, CA 94025
cpo\vell@usgs.gov
Twenty-nine names have been used for Tertiary and Quaternary Austrotrophon and
Forreria in California. Many of the described species were attributed to the genus Trophon , but
that genus is restricted to the coasts of South America. Of the 29 names, two are questionably
assigned to the family Buccinidae, another to the Muricid subfamily Rapaninae, seven to the
subfamily Trophoninae, and one questionably to the genus Nucella (subfamily Ocenebrinae).
This leaves 18 names associated with Austrotrophon and Forreria in California, one of
which is a figure caption misprint. Three are attributed to Austrotrophon and are all considered
valid. California Austrotrophon include: A. catalinensis (Oldroyd), A. kernensis (Anderson), and
A. medialis (Addicott). The remaining 14 names are referred to Forreria. A review of Forreria
has not been completed but the following species appear valid: F. belcheri (Hinds), F.
cancellaroides (Arnold), F. carisaensis (Anderson), F. coalingensis (Arnold) [syn. T. perelegans
Nomland], F. emersoni Addicott, F. milicentana (Loel & Corey), and F. wrighti Jordan &
Hertlein. Further review and examination of type specimens will help resolve the following
species: F. magister munda Stewart, T. belcheri avita Nomland, T. magister Nomland, and T.
carinaensis var. mirandaensis Grant & Eaton. Available specimens of F.? bartoni (Arnold) and
F. ? lawsoni (Clark) are poorly preserved and only questionably assigned to the genus Forreria.
In addition, two possible new species are found in the literature: one from the Miocene
Santa Margarita Formation, and a second, from the Miocene Temblor Formation. Unfortunately
specimens of the second new species have not been examined.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Temporal Community Structure and Biodiversity of Malacofauna from an
Urban New Jersey Pond
Robert S. Prezant and Eric J. Chapman
Department of Biology and Molecular Biology,
Montclair State University, Montclair, NJ 07043
prezantr@mai I .montciair.edu ; chapmane@maii.montciair.edu
Barbour’s Pond, a 55,000 m pond on Garrett Mountain, is located in Passaic County,
northern New Jersey, one of the densest urban regions in the United States. Despite its small
size and the surrounding urban sprawl, this pond, in a heavily used public park, holds 18 species
of molluscs, the most abundant being Amnicola limosa, Helisoma anceps, Pisidium casertanum,
Pisidium henslowanum and Physa acuta. Monthly samples from March 2004 through March
2005 found the highest diversity in shallow waters in March and December 2004 and January
2005. Total molluscan abundance was greatest in July and November 2004, possibly reflecting
young adults from late spring and autumn population expansions. May 2004 showed the lowest
diversity and abundance. There is also a strong correlation between frequency of occurrence and
relative abundance. Using Bray-Curtis Similarity Indices, we determined small groupings of
temporal communities. The two species of Pisidium were always found together and usually in
the presence of Amnicola limosa. These three taxa were found with Physa acuta about 90% of
the time and all four with Helisoma anceps and Goniohasis virginica over 80% of the time.
Amnicola limosa was found in every month except May 2004; Helisoma anceps every month
except February 2005. These temporal communities could be correlated with specific
environmental changes currently being examined.
Mating and Reproduction in Deroceras Slugs
Heike Reise
State Museum of Natural History Gorlitz, PF 300 154, D-02806 Gorlitz, Germany
Heike.Reise@smng.smwk.sachsen.de
Deroceras is the largest genus of terrestrial slugs with a high diversity of penis
morphologies and mating behaviors. The function of most of the appending external and internal
penis structures, sometimes truly bizarre, is largely unknown. I review mating behavior and
reproduction based on 18 species from the literature and my own observations. I analyze patterns
common to all Deroceras, and differences between species. The general mating pattern consists
of a long courtship with mutual stroking with a stimulator, a sudden penis eversion and external
sperm exchange (copulation). Sperm exchange is usually very quick, but in a few species is a
considerable proportion of the total mating duration. Mutual sperm exchange is the rule. Species
differences involve the durations of certain mating phases, presence and nature of initial trail
following, nature and intensity of stroking, including the degree of contact with the stimulator,
aggressiveness of courtship behavior, and the timing of flagellum eversion. I hypothesize that the
radiation of mating behaviors and associated structures may have been driven by an arms race
resulting from conflicting interests of mating partners over sperm donation and usage. This could
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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also have increased the rate of speciation in Deroceras. There are indications for the presence of
sperm competition and conflicting interests between mating partners: individuals mate
repeatedly, can store and digest sperm, lay many egg clutches over a long period, simultaneously
use sperm from different mating partners for egg fertilization, and some details of mating
behavior also suggest conflict.
Steps Towards a Revision of Hemphillia Jumping Slugs
Heike Reise1 and John M.C. Hutchinson2
'State Museum of Natural History Gorlitz, PF 300 154, D-02806 Gorlitz, Germany
Heike.Reise@smng-smwk.sachsen.de
2Max Planck Institute of Human Development. Lentzeallee 94, 14195 Berlin, Germany
The terrestrial slug genus Hemphillia is endemic to northwestern North America. Seven
species have been named. The slugs are largely limited to natural habitats, are often hard to find,
and at least some seem to have small ranges and low population densities. Accordingly, little has
been published about their taxonomy and biology, yet they have assumed a relevance for
conservation. The surviving type specimens of five species are useless for anatomy, and the
single type specimen of H. pantherina is immature. The few anatomical descriptions of single
species mostly suffer from a lack of detailed direct comparison with similar species. I describe
the initial results of a review of this genus, based mainly on anatomy, but also including other
aspects such as mating behavior. I examined the types of all species, including the holotypes, as
well as new specimens from the type localities of six species and from other sites (all seven
species). Genital anatomy and mating behavior indicate the existence of a sibling species of H.
malonei.
Mollusk Survey and Basic Ecological Studies
in Hells Canyon, Snake River, USA
David C. Richards1, C. Michael Falter2, Gary T. Lester3 and Ralph Myers4
'EcoAnalysts Inc., Moscow, ID, 83843
mudsnail 1 @hotmail.com
2Northwest Ecological Sciences, Moscow, ID, 83843
3EcoAnaiysts Inc., Moscow, ID 83843
4Idaho Power Company, 1221 W. Idaho St, Boise, ID 83702
We surveyed and conducted basic ecological studies of mollusks in a variety of habitats
in reservoirs, tributaries, and the main stem of the Snake River, Hells Canyon. We focused our
efforts on threatened and endangered species and species of concern by handpicking cobbles,
visual shoreline searches, and SCUBA. Results include; absence of threatened and endangered
species or species of concern in reservoir habitat; range expansion of a recently discovered new
species of the hydrobiid, Taylor concha sp.; dominance of two invasive species, Potamopyrgus
antipodarum and Corbicula fluminea; extreme rarity or absence of native unionids in the main
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 60
stem of the Snake River; and relative abundance of the limpet Fisher ola nuttalli, a species of
concern. We also related mollusk taxa abundance to environmental variables and to each other
using several multivariate statistical methods. For example, Taylorconcha sp. abundance was
directly related to P. antipodarum abundance, which suggests competition for shared habitats
and Taylorconcha sp. was not found in the first 10 river miles downstream of Hells Canyon dam,
which suggests unsuitable habitat in this section of the Snake River.
Discovery of Copulatory Structures in Male Helicinidae
(Gastropoda: Neritopsina: Helicinidae)
Ira Richling
Zoological Institute, Christian-AIbrechts-Universitat zu Kiel,
Olshausenstr. 40, 24098 Kiel, Germany
ira@richling.de
The Helicinidae represent a special family of terrestrial gastropods among only aquatic
relatives having evolved independently from other terrestrial snails. Therefore, morphological
features differ substantially, especially the reproductive system with separate sexes. Contrary to
most related families and other terrestrial gastropods with inner fertilization, male helicinids
were believed to lack special copulatory structures and the mode of sperm transfer remained
doubtful.
Only recent investigations of Papua New Guinean species of the genus Palaeohelicina
Wagner, 1905, revealed such structures. While other Neritopsina possess penes derived from the
base of the right cephalic tentacle, in Helicinidae they are developed as anappendage of the inner
mantle fold. Throughout the gastropods, a similar origin of copulatory structures is only found in
the limnic Ampullariidae.
Morphological details will be given for Palaeohelicina and the presence or absence of
copulatory structures in other genera will be analyzed. Functional aspects within the whole
family will be discussed in the light of these new findings and structural differentiations of the
female reproductive system.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Cheklist of Gastropods and Bivalves
from the Coasts of Chiapas and Oaxaca, Mexico
Eduardo Rios-Jara, Ceciel Navarro-Caravantes, Martin Perez Pena, Ernesto Lopez Uriarte and
Ildefonso Enciso Padilla
Departamento de Ecologia, CUCBA-Universidad de Guadalajara,
Carretera a Nogales Km. 15.5, Las Agujas Nextipac, Zapopan, Jalisco, 45110, Mexico
edurios@cucba.udg.mx
The marine malacofauna of the states of Chiapas and Oaxaca, located in the southern
coast of the Mexican Pacific, has been little studied. From March to June of 2004, we conducted
several collections of mollusks in eight localities of both states with representative coastal
environments: 1) Suchiate Estuary (sandy beach, estuary and mangroves); 2) Cahoacan Estuary
(sandy beach, estuary and mangroves); 3) Puerto Madero (sandy beach, estuary and mangroves);
4) La Encrucijada (estuary); 5) La Jolla-Buenavista (coastal lagoon with mangroves); 6) Boca
del Cielo (sandy beach, estuary and mangroves); 7) Puerto Arista (sandy beach); 8) Paredon
(rock jetty, estuary); 9) Huatulco (sandy and rocky beaches). Additionally, the captures of a
shrimp fishing vessel obtained from 62 sampling stations in the continental shelf (depths = 14.6-
65.0 m) were studied. A total of 2,852 specimens were quantified and classified into 2 classes
(Gatropoda and Bivalvia), 55 families, 94 genera and 170 species. The number of species of
gastropods (88) and bivalves (82) was similar, but the bivalves accounted for 64.2 % of all
individuals. The highest number of species was recorded in the continental shelf samples
(gastropods=57, bivalves=16) and in the sandy beaches (bivalves^ 5, gastropods=17). Several
species of genera Gradiarca, Pleuroploca, Ficus, Fusinus, Chicoreus, Malea, Melongena,
Haustellum and Hexaplex are of commercial interest. Two species are recorded for the first time
in the region.
Report on the Current Status of Introduced Species of Achatinidae and Other
Economically Snail and Slug Pests in the Eastern Caribbean
David G. Robinson and H. Angela Fields
1 USDA APHIS PPQ / Academy of Natural Sciences, Philadelphia, PA 19103
robinson@ansp.org
2 Department of Biological & Chemical Sciences,
University of the West Indies, Cave Hill, Barbados
The introduction of three species of the Achatinidae, Achatina fulica Bowdich, 1822,
Archachatina marginata (Swainson, 1821) and Limicolaria aurora (Jay, 1839) into the Eastern
Caribbean is documented. The giant African snail, Achatina fulica, was deliberately introduced
to Guadeloupe circa 1984. From Guadeloupe the snail was spread to Martinique by 1988, and to
Saint Martin and Marie-Galante in 1995. Populations in both Guadeloupe and Martinique
peaked in the 1990’s and subsequently have fallen to relatively stable levels. Prior to 2000, A.
fulica was introduced into Saint Lucia, and from there to Barbados in early 2000. On both these
islands, populations of the species are increasing exponentially and spreading across the islands,
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 62
despite the efforts of the local ministries of agriculture. Archachatina marginata was introduced
from Benin to the Saint Joseph area in Martinique in 1987, but the species has not been found
since; surveys in early 2005 did not detect its presence. Limicolaria aurora was introduced into
Martinique in 1988, and is slowly extending its distribution through central Martinique, in some
areas replacing populations of A. fulica. The current status and distribution of three pest
veronicellid slugs, Veronicella sloanei (Cuvier, 1817), Veronicella cubensis (Pfeiffer, 1840) and
Saras inula plebeia (Fischer, 1868) are also documented, together with that of three other pest
snails, Zachrysia provisoria (Pfeiffer, 1858), Bradybaena similaris (Rang, 1831) and
Amphibulima patula dominicensis Pilsbry, 1899. Their potential impact on agriculture and the
environment in the Eastern Caribbean is discussed.
Report on the Spread of the Cuban Slug Veronicella cubensis (Pfeiffer, 1840) in Guam and
Rota in the Northern Mariana Islands, and the Loss of Mollusean Biodiversity Apparently
Resulting from Introduced Invasive Gastropod Species and the Triclad Flatworm
Platydemus manokwari de Beauchamp, 1963
David G. Robinson and Robert G. Hollingsworth
1 USDA APHIS PPQ / Academy of Natural Sciences, Philadelphia, PA 19103
robinson@ansp.org
2 USDA ARS PWA, US Pacific Basin Agricultural Research Center, Hilo, HI, 96720
As part of a study of snail and slug pests on subsistence and garden crops on islands in
the American Pacific, the islands of Guam and Rota were surveyed for terrestrial gastropods in
August 2004. Non-native, invasive species are by far the most pervasive elements of the
malacofauna on both islands, with Veronicella cubensis reaching epidemic proportions on Rota.
The Cuban slug is ubiquitous throughout synanthropic to relatively natural environments on both
islands, and most of the agriculture and horticulture are being severely affected. Living
specimens of native species as well as many other introduced snail species are now a rarity
especially on Rota, their occurrence as documented by Bauman (1996) in the recent past
indicated only by dead, eroded shells. Previously introduced snail species appear to have been
decimated or even eradicated by more recent introductions, in particular Platydemus manokwari ,
and hope for the survival of native snail species in these islands appears remote.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 63
Comparative Phylogeography of Chitons and Limpets in Southern California
■•10 1
Albert Rodriguez , Ryan P. Kelly and Douglas J. Eemisse
'Department of Biological Science, California State University, Fullerton, CA 92834
arl 3351 5@student.fiiiierton.edu
Department of Ecology, Evolution, and Environmental Biology, Columbia University,
and Department of Invertebrate Zoology, Molecular Systematics Laboratory,
American Museum of Natural History, Central Park West at 79th St., New York, NY 10024
Chitons and limpets are important ecologically and are mainly dispersed by the
movement of their non-feeding pelagic larvae. It has long been assumed that the biogeographic
break between the Oregonian and Californian provinces occurs at Point Conception in Southern
California. In recent years some researchers have contested this long held assumption and have
found species of fish, copepods and other animals whose ranges span Point Conception. Authors
who have reanalyzed available phylogeographic data have concluded that the vicinity of Palos
Verdes Peninsula in Los Angeles is a more likely phylogeographic break than Point Conception.
In our study we will investigate whether this pattern generally holds for chitons and limpets and
perhaps marine molluscs in general by comparing regions of the mitochondrial genes 16S and
cox- 1 (COI) from up to seven chiton species and up to six limpet species. Comparative
phylogeographic analysis of the gene sequences will reveal whether Palos Verdes has been a
significant barrier to gene flow. If genetic structure is consistently found between populations
north and south of Palos Verdes then we can support the assertion that there has been an
effective barrier to gene flow at or near Palos Verdes. If so, this physical barrier could have
promoted speciation events and thus could have contributed to the impressive diversity of coastal
organisms in southern California.
Taxonomic Revision of Endemic Nicaraguan Freshwater Mussels (Bivalvia: Unionidae)
Kevin J. Roe and Adolfo Lopez de la Fuente
'Delaware Museum of Natural History, Wilmington, DE 19810
kroe@delmnh.ors
=>
University of Central America, Managua, Nicaragua
Lake Managua and Lake Nicaragua are home to a group of endemic species of unionid
mussels. As with many other unionids, these species were described in the middle part of the
19th century. These descriptions were based almost entirely on conchological characters that
make assessment of the systematic relationships of these species and their taxonomic placement
relative to other unionids difficult to assess. These eight species have been placed into several
different genera over the years e.g. Plagiola, Ptychoderma, Micronais, Arotonais , and unlike
unionids from the United States and Canada have been largely ignored for the last century.
Examination of existing museum holdings of these taxa represents the first stage in the
preparation of a monographic revision of the unionoid bivalves of the Central Nicaraguan lakes.
Specimens, including type material were photographed and measured and evaluated with respect
to published descriptions and synonymies. Based on the examination of existing specimens and
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 64
descriptions the 1 1 nominal taxa endemic to the Nicaraguan lakes are placed in 6 species in two
genera. Significant work remains to be done, including examination and description of gravid
female specimens and their glochidia before a more complete picture of the number of species in
the lakes and their affinities to other members of the Unionidae emerges.
Developmental and Phenotypic Integration in Bivalves:
Adaptation and Evolution of the Neogene Venerid Genus Chione
i i ^ -5
Peter D. Roopnarine , Kenneth Angielczyk , Viviane Callier and Laurie C. Anderson
'Department of Invertebrate Zoology & Geology,
California Academy of Sciences, San Francisco CA 94118
proopnarine@calacademv.ore:
“Department of Biological Sciences, Mt. Holyoke College, South Hadley, MA 01075
department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803
Morphological integration is defined as an emergent property of individual ontogenies,
populations, and clades. Integration is a pattern of relationships among morphological characters
at the level of the organism, but the topology and variation of this pattern at different hierarchical
levels may dictate whether integration promotes or constrains evolution. We examine this
problem by describing morphological integration in Chione, a clade of Neogene venerid
bivalves. We archive the shape of individual valves using geometric morphometric landmarks,
and extract from this archive estimates of developmental integration and phenotypic integration.
Patterns of integration are estimated for several species from the western Atlantic and eastern
Pacific, and sampling of each species includes multiple populations spanning geographic and
geologic ranges.
Landmarks or traits within a shell are considered to be integrated if they are
mathematically correlated. The correlations are generally associated with developmental or
genetically homologous (pleiotropic) relationships. Developmental integration can be estimated
as the correlations of characters with a common growth vector. This estimate of integration is an
emergent group property, and may vary between populations and species. Independent of
developmental integration however, are the residual correlations among sets of landmarks within
a population. Both this latter phenotypic integration and developmental integration determine the
responses of populations and species to agents of micro- and macroevolution, and may explain
the phenotypic variability of molluscan shells. We estimate the patterns of integration using two
alternative methods: (1) empirical multivariate estimates of partial correlations among
landmarks, and (2) Bayesian modeling of developmental and phenotypic correlations.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Evolution of the Palau Diplommatinids and Conservation of the Land Snails of
Palau and the Southwest Islands
Rebecca J. Rundell
Committee on Evolutionary Biology, 1025 East 57th Street,
University of Chicago, Chicago, IL 60637,
and Department of Zoology, Field Museum, 1400 S. Lake Shore Drive, Chicago, IL 60605
mndeli@uchicaso.edu
The western Micronesian islands of Palau comprise over 350 islands, many of which are
less than 1 km2. Babeldaob, the largest island, is only 333 km2, and represents 80% of Palau’s
total land area. Despite the small size of the islands, the species richness of Palau’s land snail
fauna is extraordinary. This may be due in part to the varied geology of the islands, which are of
both volcanic and coralline (limestone) origin and encompass high and low limestone island
types, atolls, high volcanic islands, and islands that consist of both limestone and volcanic rock.
The minute, endemic diplommatinid land snails are found throughout the Palau archipelago on
all island types. In my 2003 survey, 39 diplommatinid species were found on 20 islands; many of
these species are undescribed. In a single locality, as many as five diplommatinid species were
found to co-occur. Diplommatinids are found in leaf litter, on limestone rock faces and in
limestone rubble, and shell morphology roughly correlates with substrate type. Preliminary
sequence data from 16S rDNA suggest complex biogeographical patterns among Palau
diplommatinid species and, unsurprisingly, a need for systematic revision of the group. A
thorough census of non-diplommatinid land snails in Palau was also conducted, and comprised
all 16 states, including the relatively unknown and isolated low limestone Southwest Islands.
Notably, live endodontids and partulids were found. Although Palau’s rainforest remains largely
intact, relative to many other Pacific island groups, recent development on the island of
Babeldaob in particular is cause for conservation concern.
The Evolution of Exoskeleton Nucleation
in Shelled Fossils and Holocene Molluscs
Amelie H. Scheltema
Biology Department, Woods Hole Oceanographic Institution MS #34, Woods Hole, MA 02543
ascheltema@whoi.edu
Nucleation sites of CaCC>3 in exoskeletons of Holocene molluscs can be related to
exoskeletons in Paleozoic molluscs and mollusc-like taxa. Nucleation sites have been identified
from the literature. They can be divided into taxa with and without a periostracum that is
secreted in a groove of the mantle edge. In those taxa without a periostracum: (1) Nucleation is
within epidermal cells. The resulting sclerites are retained in cuticle secreted by epidermal cells
over the general body surface (Aplacophora, geologic age unknown; Polyplacophora, Halkieria,
Cambrian). (2) Nucleation and growth is within epidermal cells as sclerites that accreted in rows
held by body cuticle, later mineralized to form a solid shell ( Maikhanella multa, Cambrian). In
taxa with cuticle restricted to periostracum: (3) Nucleation is within individual cells of the
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 66
epidermis. The prisms grow out of the ceils, fuse together, and then fuse to periostracum
{Nautilus, monoplacophorans? Paleozoic). (4) Periostracum is in three layers, outer and middle
formed within the periostracal groove, the inner by mantle epithelium. The vacuolated middle
layer is the site of nucleation and prism growth ( Amblema , Mytilus, Holocene). (5) Nucleation is
on the periostracum from ions in the extrapallial fluid between the epithelial cells of the outer
mantle fold and periostracum/shell (most Holocene Conchifera). The great diversity of extant
molluscs is attributed in part to the evolutionary loss of sclerites and development of
periostracum and a fluid-filled extrapallial space, allowing greater freedom of movement within
the shell and in the outside environment.
Understanding the Evolution and Development of Pallial Eyes in the Pectinidae
Jeanne M. Serb
Ecology, Evolution & Organismal Biology, Iowa State University, Ames, IA, 5001 1
Evolutionary developmental biology, or evo-devo, is a nascent field that aims to
understand the evolution of developmental processes underlying phenotypic change across taxa.
Achieving this aim requires data from diverse disciplines including genetics, embryology,
paleontology, and systematics. Although evo-devo studies have been conducted in many
metazoan phyla, the second largest phylum Mollusca has been so far underrepresented. Scallops,
in the families Pectinidae and Propeamussiidae, offer a rich system to examine major evo-devo
questions as they are: 1) diverse with 400 extant species distributed worldwide, 2) have a well-
studied embryology, and 3) possess variable traits that are easily compared anatomically and
developmentally. I will describe my research on the evolution of pallial eyes and their spatial
arrangement in scallops. This research program will address broad evo-devo questions of the
scallop eye. How is eye organogenesis initiated? What are the major contributors in
determining eye symmetry - developmental constraint, historical constraint, or ecology? Is the
behavior of the adult animal a good predictor of symmetry? First, I will discuss the taxonomic
status of scallops and present a new phylogenetic tree based on mitochondrial and nuclear gene
sequences. Then, I will present the wide phenotypic variation in the number and arrangement of
eyes across species. Finally, I will place these different phenotypes in a historical context and
discuss our expanding knowledge eye of development and evolution in scallops.
Flat Oysters Show Evidence for Allopatric Speciation, Ecological Transition and
Introgression Among Developmentally Heterogeneous Taxa
Meghan H. Shilts
Museum of Zoology, The University of Michigan, Ann Arbor, MI 48109-1079
mshilts@unnich.edu
This study focuses on five nominal species of flat oysters that occur in multiple ocean
basins and tests their phylogenetic relationships using a mitochondrial marker (cytochrome c
oxidase I; COI) and nuclear internal transcribed spacer (ITS-1 and ITS-2) gene fragments. My
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 67
data were consistent with allopatric speciation expectations: all five nominal taxa have sister
lineages in different ocean basins. Although the western South Atlantic Ostrea puelchana and
the western North Atlantic Cryptostrea permollis differ radically in their ecologies and
reproductive modes, these two species shared a common ancestor recently enough that they have
not yet attained reciprocal monophyly in rooted mt gene trees. C. permollis’ commensal
relationship with sponges - the only living oyster that does not cement on hard substrates -
apparently represents an evolutionarily recent ecological transition. My data also revealed that
the Mediterranean Ostreola stentina is a member of the same sibling species complex as the
western North Atlantic Ostreola equestris and the New Zealand Ostrea auporia. Analysis of
COI variation showed that these three taxa are closely related but reciprocally monophyletic for
this mt marker but polytomous for the slower evolving mt 16S and nuclear ITS-1 markers.
Unexpectedly, O. auporia exhibited a nuclear/mitochondrial disjunction with a phylogenetically
and developmentally distinct species, O. chilensis, in the North Island of New Zealand. To my
knowledge, this represents the first instance of apparent hybridization among marine
invertebrates with different developmental modes.
Diversity of Terrestrial Snails on the Three Largest Islands in the
Louisiade Archipelago, Papua New Guinea
John Slapcinsky
University of Florida, Florida Museum of Natural History, Gainesville, FL 3261 1-7800
slapcin@flmnh.ull.edu
The Louisiade Archipelago, a group of volcanic islands and coral islets, with a total area
of approximately 1600 km2, lies about 300 km east of the New Guinea mainland and 400 km
west of the Solomon Islands. The Louisiades are at least 15-20 million years old but more likely
were formed 40-60 million years ago and have apparently never had a land connection with the
New Guinea mainland. The archipelago’s physical isolation and great age combine to provide
considerable opportunity for the evolution of a distinctive fauna. However, this fauna has
remained largely unknown, especially for invertebrates, including terrestrial snails. Only a few
brief surveys and small collections made in the mid to late 19th century led to the description of
the approximately 35 species of land-snails known from the archipelago. Low sampling
intensity and poor geographic coverage combined with high levels of endemism suggest that
land snail diversity in the archipelago is under-sampled, a view supported by ten weeks of field
surveys in January 2003 and April-May 2004 on the three largest islands in the Louisiade
Archipelago: Misima (St. Aignan), Vanatinai (Sudest, Tagula) and Yela (Rossel). These surveys
uncovered many undescribed snails, nearly all of them endemic to a single island.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 68
A Re-description oiMarionia rubra (Riippell and Leuekart, 1831)
Victor G. Smith and Terrence M. Gosliner
Department of Invertebrate Zoology and Geology, California Academy of Sciences,
55 Music Concourse Dr., Golen Gate Park, San Francisco, CA 94118
vsmith@calacademv.org
The morphology and anatomy of 1 5 preserved specimens from Okinawa, the Philippines
and Tanzania are closely examined. Based on general appearance, digestive armature and
reproductive systems, these animals are similar enough to comprise a single species. However,
the photographs of the living animals vary widely in color and to a lesser extent pattern.
Color/pattem variations occur within as well as between localities, and do not appear to be on a
geographic gradient. Other evidence suggests that variability may be even greater than that
observed in the present study.
The taxonomy of the tritoniid nudibranchs of the Indo-Pacific region remains poorly
understood. Early descriptions based only on external features, and inconsistent later
descriptions of important anatomical characters are only the first obstacles for workers to
overcome. Some animals are known only from their original description, and may not have been
collected and examined again. In addition, there remains some controversy over the characters
used to delineate the existing genera, and over which genera and species are valid.
Descriptions of the animals in the present study are compared with published descriptions
of Marionia viridescens (Eliot, 1904), M. albotuberculata (Eliot, 1904), M. dakini (O’Donoghue,
1929) and M. rubra (Riippell and Leuekart, 1831). Of these, M. rubra is believed to be the
earliest valid name for this species, and the rest are proposed as junior synonyms.
Stable Isotope Growth Profiles of Holocene and Cenozoic Mollusks
Josiah Strauss and Anton Oleinik
Department of Geosciences, Florida Atlantic University, Boca Raton, Florida. 3343 1
istraus2@fau.edu. aoleinik@fau.edu
Oxygen and carbon stable isotope concentrations were measured from carbonate samples
taken along the incremental growth of molluscan shells. Isotopic data were used to determine
and compare shell growth histories of six Holocene and fossil genera of mollusks: three genera
of gastropods - Triplofusus, Fasciolaria, and Beringius, and three genera of bivalves - Dosinia,
Anadara, and Codakia. These taxa were selected to check for compatibility of results between
fossil and modem genera from similar environments. Furthermore, the isotopic profiles were
used to determine a latitudinal change in isotopic values from low to high latitude localities.
Comparison between isotopic profiles of modem and fossil congeneric species allows insight
into seasonal shell growth rates, metabolic activity and environmental conditions. Isotopic
profiles of gastropods exhibit more coherent growth profiles and are generally longer lived than
the examined bivalves. Shell growth differs between congeneric fossil and modem species,
probably as a result of different environmental conditions during the Pleistocene. Holocene
specimens were collected from the Gulf of Aniva, Gulf of California, Bahamas, Florida Keys,
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 69
and Gulf of Mexico. Fossil specimens were collected from the Early Middle Miocene of
Kamchatka and the Pleistocene of southern Florida. Data appear to be reliable for most
specimens, showing that accurate proxy data can be obtained from isotopic studies in marginal-
marine environments. Oxygen isotope ratios were also used to infer ambient seawater
temperatures during the deposition of each shell. Calculated temperatures offer significant
insight into the paleoceanography of the Pleistocene southern Florida embayment and early
middle Miocene climatic optimum in the North Pacific.
Differential Expression of Vetigastropod Hemocyanin
Klaus Streit and Bernhard Lieb
Ir» cf l ti it£» rvf 7r\n\ncr\r Tnbonnac TTi if^r»Kot*rr_T Ttnix/ovoi-f-vr IA = ^ oin?
ULrvitUVV VI ) <) VIIUIIUVJ VJUlVlIUVlg ' 1X1 r VI Jl K.J , 1_/ w'w' vy S lVlU1114i,
Gc.
VJVUllUllj'
lieb@unimainz.de
Molluscan hemocyanins are blue copper-containing respiratory proteins that are found in
a number of gastropods in two immunologically distinguishable isoforms. In general, these
isoforms do not occur in equal molar ratios but are differentially expressed. In Haliotis
tuberculata (Haliotidae), for example, the two isoforms are present in an average molar ratio of
9:1, whereas in Megathura crenulata (Fissurellidae) the average molar ratio is 1:3. Analyses of
the complete cDNAs of these four hemocyanin isoforms do not reveal any significant codon bias
or any abnormal amino acid accumulation. Quantification of isoform specific mRNAs within
these species show that different amounts of transcripts exist that, however, do not correspond to
the protein amounts observed. Additionally, we could show that the two hemocyanin isoforms of
Haliotis asinina are expressed in a tissue-specific manner. For that purpose, we are investigating
the hemocyanin genes with special focus on promotor regions. Preliminary results show that the
promotors possess typical TATA-boxes and a number of other theoretically identified cis-acting
elements. Thus it appears that expression of these isoforms is differentially regulated by
transcriptional control mechanisms and in addition by the translational machinery and/or protein
turnover rates.
New Morphological Data for Pleuroceridae (Gastropoda: Cerithioidea):
Implications for Monophyly and Affinity of the Family
Ellen E. Strong
Department of Invertebrate Zoology, Smithsonian Institution,
National Museum of Natural History, Washington DC, 20560
StrongE@si.edu
The family Pleuroceridae comprises one of the most abundant and species rich
assemblages of limnic mollusks occurring in North America and Eastern Asia. In North
America, they are represented by 7 genera and estimates of ~ 160 species are currently considered
valid. Despite their ecological importance, their systematics at all levels remains poorly
understood. A rigorous systematic revision of all species and genera is lacking and uncertainty
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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exists as to the precise limits of the family. Moreover, all taxonomic treatments of the family
have been done in the absence of a broad comparative understanding of morphology.
B.C. Dazo’s classic account of Pleurocera acuta and Goniobasis livescens is the most
thorough work available for pleurocerid anatomy. However, this study was completed long
before our present knowledge of freshwater cerithioidean anatomy was in place. In particular, we
now have a much more thorough understanding of the structure, function and homologies of the
pallial gonoduct as well as other organ systems (e.g. midgut, kidney) and their phylogenetic
utility.
Consequently, especially given the persistent paucity of anatomical data available for the
family, the anatomy of these two species is re-described, with particular emphasis on the re-
interpretation of pallial oviduct homologies; features not covered by Dazo (midgut and kidney)
are newly described. This analysis reveals a number of presumably synapomorphic features
unique to pleurocerids as compared to other limnic lineages in characters of the midgut, albumen
gland and pallial kidney extension. The implications of these findings for clarifying the
monophyly and affinities of the Pleuroceridae are discussed.
Reproductive Behavior of the Dioecious Tidal Snail,
Cerithidea rhizophorarum (Gastropoda: Patamididae)
Maya Takeuchi, Harumi Ohtaki and Kiyonori Tomiyama
Department of Earth and Environmental Sciences, Faculty of Science,
Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan
The dioecious snail Cerithidea rhizophorarum is found throughout the coasts of the
western Pacific up to the Tohoku district northward in Japan. It inhabits reed grassland and
mangrove forest on mud flats. In Kagoshima prefecture, this species are commonly found in a
mangrove forest with Kandelia candel and Hibiscus hamabo trees on a mud flat located at the
mouth of Atagogawa River in Kiire. Interesting mating and tree climbing behavior of this species
were studied on this mud flat, for approximately two years from April 2000 to May 2003.
Mating behavior was observed in July and August 2002. The time of commencement
duration and termination, were recorded for each copulation. The peak of matings during
daytime was seen 1 to 2.5 hours before the lowest tide, and that during nighttime between 1 hour
before and after the lowest tide. However, the mating almost did not occur on cloudy days.
Climbing behavior was observed in an area of 1 00 square meters where only Kandelia
candel trees existed. The number of snails on the tree was counted and daily activity of the snails
on trees was monitored in summer and winter, counting the number of the snails on the tree
every one hour throughout the day. The snails were mainly found on the mud from spring to
summer, frequently climbed up the tree during particular times in the summer, and most
individuals were seen on trees and motionless during winter.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 7 1
Detecting Stability and Change in Fossil Communities:
the Need for Temporal- and Scale-dependent Perspectives
Carol M. Tang
California Academy of Sciences, 55 Music Concourse Dr., Golden Gate Park, San Francisco, CA 941 18
ctang@calacademv.org
The strict application of ecological patterns and processes to the fossil record is severely
limited because of loss of soft-bodied flora and fauna, difficulties of measuring biomass, virtual
inability to reconstruct direct biotic interactions, and most significant of all, time averaging of
individuals which never lived contemporaneously. Documented patterns of paleocommunity
stability should more accurately be compared to the neo-ecological concept of resilience rather
than resistance. While succession and other short-term processes can only be examined under
unique preservational conditions, time-averaged “paleocommunities” possibly spanning
thousands of years do allow for the study of patterns and processes in evolutionary paleoecology.
Molluscs are a good system with which to ask paleoecological questions because they
exhibit a range of trophic strategies, are geographically distributed, have a long fossil record, and
inhabit a number of ecological and environmental niches. In addition, many taxa have good
preservational potential. However, even with molluscs, detailed sedimentological,
paleoenvironmental, and taphonomic studies should be employed to assess the limitations of
paleocommunity analysis.
For example, in the right depositional systems, paleocommunities can preserve local
geographic patchiness and short-term environmental excursions; even with time averaging and
transport of individuals, a great amount of small-scale geographic and temporal resolution can be
obtained using the appropriate proxies given preservational biases. In this talk, many different
proxies including species abundance, individual abundances, species presence/absence,
comparison of left and right valves, morphometric and paleocommunity structure are compared
to reconstruct different paleoecological conditions exhibited by mollusk-dominated Neogene
marine fossils of the Dominican Republic.
The Year of the Pond Snail
Andries Ter Maat, Cora Montagne-Wajer and Joris M. Koene
Faculty of Earth and Life Sciences, Vrije Universiteit, Amsterdam, Netherlands
The hermaphroditic pond snail Lymnaea stagnalis has long been used as a laboratory
model for the study of neurohormonal regulation of reproduction and growth. In parallel, the
allocation of resources towards reproduction, growth and maintenance has been studied as a
means to understand the hermaphrodite’s life-history. To gain insight into the seasonal changes
of resource allocation towards female and male function, as well as towards body growth we
have collected snails in a Dutch ditch for over two years on a monthly basis. The weights of the
prostate gland and albumen gland were determined as well as body size and (dry) weight.
Animals that survive the winter months (December to March) copulate at the start of spring. A
few weeks later, egg masses appear from which the next generation hatches, grows and matures
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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in about two months. As last year’s generation dies off, the new one becomes sexually active.
This means that there is little opportunity for copulation between generations. The last egg
masses, laid by the new generation, are laid around the autumnal equinox. Towards summer,
both generations show a decrease in dry weight density suggesting that the snails apply the
acquired energy to reproductive output instead of storing it. The results obtained in the ditch are
compared with laboratory studies on the physiology of reproduction, as well as on sex allocation.
Missing Pieces in the Speciation Puzzle: an Example of the Palaeontogical Imperative in
Interpreting Biogeographic Patterns in a Neotropical Marine Gastropod Radiation
Jonathan A. Todd
D
rvf D-.
vpui inivm ui i C4.ii
aeontology, The Natural History' N-Iuscum, London, S\V
i.todd@nhm.ac.uk
Inference of speciation mechanisms and sister species relationships are staples of
evolutionary analyses, but are done almost exclusively on extant taxa. Distributions of living
animals are generally taken as representative of the interplay between the biogeography of
ancestral lineages and the (often vicariant) mechanisms that drove divergence. Full sampling of
all members of a clade is correctly encouraged, but commonly excludes all but the denizens of
the thinnest slice of geological time - time zero, the Holocene. The missing players of extinct
taxa and the shifting stage of changing distributions through time are often brushed over or
omitted as being too challenging. Detailed sampling through space and time of a species-rich
molluscan clade allows us to test whether these simplifying assumptions are justified, or whether
they bias our results. I present an example - the Neotropical turrid genus Polystira - that consists
of narrow and widespread, rare and abundant, fossil and Holocene species, to illustrate the
contribution fossils make to understanding present day biogeography. This genus consists of
numerous living and extinct cryptic, undescribed species whose discovery has been expedited by
a combination of molecular genetic analyses with conchological studies of fossil and Holocene
specimens.
Biomineralization in the Radula of the Aplacophoran Mollusk
Helicoradomenia (Solenogastres)
Christiane Todt
Department of Biological Sciences, The University of Maine, Orono, ME 04469
christiane@todt.or.at
As the major feeding organ in mollusks, the radula is frequently exposed to high
mechanic stress. In general, it is composed of a flexible membrane with a set of considerably
harder teeth attached to it. Specialized cells of the radular sheath, the membranoblasts and
odontoblasts, constantly regenerate both the membrane and teeth while worn teeth are shed into
the mouth cavity or occasionally retained within the subradular pocket. The hardness of radular
teeth is due to biomineralization processes that occur within the chitin-rich organic matrix of
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 73
newly produced teeth. These processes are best known for chitons (Polyplacophora) and some
gastropods but biominerals also occur in the radula of caudofoveates (Caudofoveata =
Aplacophora, Chaetodermomorpha).
Here, the first evidence for the presence of biominerals in a solenogaster radula is
presented, and ultrastructural features of the radula-producing cells and young teeth are shown.
The radula of Helicoradomenia “tica” (Solenogastres = Aplacophora, Neomeniomorpha) was
investigated by means of transmission electron microscopy, scanning electron microscopy, and
energy-dispersive X-ray microanalysis. The analyses show that the level of overall
mineralization is low but that a variety of mineral-composing elements do occur including
calcium, phosphorus, iron and zinc. Concentrations of these elements change gradually over each
tooth resulting in considerable differences in the chemical composition between basal radular
plates and distally located denticles. Specific biomineralization of radular teeth thus seems to be
a broader trait of the molluscan radula.
Impacts of Urbanization on the Biodiversity of the Imperiled Snail Fauna (Gastropoda:
Prosobranchia: Pleuroceridae) of the Cahaba River, Alabama, USA
Lori Tolley- Jordan
Department of Biological Sciences, University of Alabama, Tuscaloosa AL 35210
Toile004@bama.ua.edu
The conservation of the Pleuroceridae is of concern in the Mobile River Basin (MRB)
since 31 of 38 extinct gastropod species from this drainage are pleurocerids. The fauna of the
Cahaba River, as a global hot-spot for pleurocerid diversity, is of particular concern. Flows in
the river are not regulated by dams, so gastropod diversity has not been affected by habitat
alteration due to impoundment like other major MRB tributaries. Ongoing urbanization within
its watershed, however, is expected to have consequences for its snail fauna. A 1993 survey
documented 23 pleurocerid species among 1 09 sites in the drainage. Changes in land cover from
1992 to 2004 were quantified using GIS for 10 of these. Five sites showed a 13-36% increase in
urban land cover; five showed no change. Elimia cahawbensis, E. carinifera , E. carinocostata ,
E. clara and Pleurocera vestita occurred among these sites during 1993 (S = 0-4 spp./site) A
comparison of species occurrence in 1992 and 2005 showed no change in S at 6 sites, while three
lost 1 species, and one lost 3 species. However, reductions in S were not correlated with changes
in land cover. Factors not directly correlated with urban land cover may thus be contributing to
losses of snail diversity in the MRB.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Inducible Defense in a Marine Snail: Cue Sensitivity and the Scaling of Trade-offs
Geoffrey C. Trussed
Marine Science Center, Northeastern University, 430 Nahant Road, Nahant, MA 01908
g.trussen@neu.edu
Predator-induced defenses appear to be ubiquitous in marine systems yet little attention
has been paid to how they may shape large-scale patterns of phenotypic variation. Here I
consider how the invasion of the green crab ( Carcinus maenas ) into the Gulf of Maine has led to
the evolution of geographic differences in shell thickness and shell thickness plasticity in the
marine snail Littorina obtusata. Because the historical impact of Carcinus maenas in the Gulf of
Maine changes with latitude, I examined how geographic differences in shell thickness plasticity
may have evolved in response to different risk cues. I also examine how trade-offs in snail body
mass, which influence snail fecundity, correlate with the magnitude of induced defense
employed by the snail. Finally, theory predicts that natural selection should minimize the impact
of trade-offs associated with an inducible defense, thereby making them difficult to detect
experimentally. I explore this issue by explaining (1) why such trade-offs are indeed readily
detected in marine snails, and (2) why the scaling of such trade-offs shows no geographic
differentiation when one would expect otherwise.
Texas Seashells: a New Illustrated Guide
J.W. Tunnell, Jr., N.C. Barrera, R. Davenport, D. Hicks, and J. Andrews
Center for Coastal Studies, Harte Research Institute,
Texas A&M University-Corpus Christi, Corpus Christi, TX 78412
nbarrera@faicon.tamucc.edu
The last comprehensive work on Texas seashells was compiled by Jean Andrews over 30
years ago (1971, 1977). Her book Shells and Shores of Texas describes approximately 350
species of molluscs. In a collaborative effort, we are preparing an updated and expanded book on
Texas seashells. Presently, the list of molluscs in the marine environments of Texas equals over
1400 species from the estuarine shoreline to the deep Gulf of Mexico. Because of the large
number of species and inaccessibility of many of these molluscs, principally from older
collections of offshore deep water habitats, accounts of molluscs with descriptions and
photographs will be confined to habitats not exceeding 1 8 m (60 ft), but will also include Stetson
Bank and the Flower Garden Banks. Approximately 750 species of molluscs are known from
these habitats, and will be individually illustrated and described in the book. A complete
checklist of all species including depth ranges and habitat will be included in the book along with
a research history of conchology/malacology in Texas, biology and ecology of classes and
families of molluscs, and favorite collecting habitats and localities.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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Crossing the Pond: Dorid Nudibranch Strategies for Transatlantic Dispersal
Angel Valdes and Alvin Alejandrino
Natural History Museum of Los Angeles County,
900 Exposition Blvd., Los Angeles, California 90007
aavaides@esupomona.edu
Thirty-four species of dorid nudibranchs have amphiatlantic geographic ranges in the
Northern Hemisphere, with populations on both sides of the Atlantic Ocean. The other 227
species are restricted to either the east or the west coast. Larval transport has been traditionally
considered the main mechanism for nudibranch dispersal and gene flow between amphiatlantic
populations. However, some amphiatlantic species have direct development or short-lived larval
stages, suggesting the possibility of alternative dispersal mechanisms.
There is a statistically significant higher number of bryozoan/tunicate/bamacle-feeding
species with amphiatlantic ranges compared to sponge-feeding species. These differences
suggest that factors other than larval transportation may affect dispersal of dorid nudibranchs
across the north Atlantic. Bryozoans, tunicates and barnacles are some of the most common and
diverse organisms on floating debris and slow moving vessels, while sponges are much more
uncommon and scarce. Nudibranchs have been found actively feeding and reproducing on
bryozoans fouling floating objects. The results obtained suggest that adult transportation on
floating objects may account for the transatlantic ranges of some species. However, with the
available data, the amount of larval dispersal influencing amphiatlantic distribution in the boreal
region cannot be determined.
Unexpected Diversity Recovered with Experimental Wood Deployments
in the Deep North Pacific Ocean
Janet R. Voight
Department of Zoology, The Field Museum, 1400 S. Lake Shore Dr., Chicago, IL 60605
JVoight@FMNH.org
Wood and other vegetation from terrestrial systems is sometimes transported to the open
ocean where it sinks. Such wood-falls are argued to be of great ecological importance in the
deep sea due to the otherwise scarce resources they offer, but the animals that exploit these
resources remain poorly known. To document the wood-fall fauna of the deep North Pacific
Ocean, in 2002 sets of 18” long lengths of fir and oak were deployed at seven sites between 3230
and 1550 m depth from 41° to nearly 48° N, all at least 100 miles off the North American coast.
Deployments were made with Remotely Operated Vehicles (ROV’s) which allowed them to be
precisely located for recovery. Recoveries in 2003 were made with the ROV’s ROPOS and
Jason //; in 2004, recoveries were made with the DSV Alvin.
Dominant among the wood-associated molluscan fauna in both years were wood-boring
clams of Xylophaga Turton. These are among the most abundant and familiar colonists of deep-
sea wood-falls, considered to be the deep-sea ecological equivalent of teredinids (ship-worms).
Although only one species, X. washingtona Bartsch, 1921, had been reported from the Northeast
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 76
Pacific, five new species of Xylophaga were collected from the recoveries, as was a new species
of Xylopholas Turner, 1972, a genus previously known only from above 400 m depths in the
Atlantic Ocean. Newly discovered aspects of the biology of these species, their distribution and
evidence of ecological interactions within the wood-fall are reported.
Taxonomic Distribution and Phylogenetic Utility of Gender-associated
Mitochondrial Genomes in the Unionoida (Bivalvia)
Jennifer M. Walker1, Jason P. Curole2, Arthur E. Bogan3,
G. Thomas Watters4 and Walter R. Hoeh1
'Program in Ecology and Evolutionary Biology, Department of Biological Sciences,
Kent State University, Kent, OH 44242
i wal ker4@kent.edu
2University of Southern California, Los Angeles, CA 90089
3North Carolina State Museum of Natural Sciences, Raleigh, NC 27607
4The Ohio State University, Columbus, OH 43212
Three bivalve orders (Mytiloida, Veneroida, and Unionoida) are known to exhibit a
unique mode of mitochondrial DNA inheritance termed doubly uniparental inheritance (DUI).
In this type of inheritance, there are two distinct genomes present: a female transmitted (F)
mitotype and a male transmitted (M) mitotype. Three of the five families within the Unionoida
have been found to exhibit DUI (Unionoidae, Margaritiferidae, and Hyriidae). All tissues
sampled from individuals in the Iridinidae and Mycetopodidae yielded F sequence. Published
sequences of the junction between the cytochrome c oxidase II ( cox2 ) and cytochrome c oxidase
I ( coxl ) genes of M unionid genomes revealed an approximately 600 bp extension of the 3’ end
of the cox2 gene which is absent from the F genome. We detected F as well as M length
variation in the cox2 gene with a much greater level of variability in the latter. Amino acid
compositional analyses suggest that the M cox2 extensions are relatively hydrophobic and
analyses of M cox2 extension secondary structure revealed the presence of a variable number of
transmembrane helices (Unionoidae 3-5; Margaritiferidae 0; and Hyriidae 4). Previous
phylogenetic analyses of M and F cox2 - coxl sequences reveal separate F and M clades that
exhibit similar topologies. Analyses presented herein were conduced using separate M and F
cox2 - coxl sequence matrices as well as concatenated M and F cox2 - coxl sequences.
Examination of Lineage Diversity and Isolation of
Oreohelix strigosa cooperi , Black Hills, South Dakota
Kathleen Weaver, Tamara Anderson and Robert Guralnick
Invertebrates, El 76 Museum Collections Building,
University of Colorado Museum of Natural History, Boulder, CO 80309
Robert.Curalnick@colorado.edu
The Rocky Mountain Snail, Oreohelix (Oreohelicidae), is one of the most abundant and
characteristic land snail genera in the Western United States. The genus consists of
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 77
approximately 120 species, mostly restricted to moist alpine environments. We have begun to
examine the lineage diversity and biogeography of Oreohelix using primarily molecular
systematic approaches. Our goals are two-fold. We are particularly interested in lineages that
have been listed as conservation concerns. High endemicity within Oreohelix has led federal and
state agencies to list or propose listing (as threatened or endangered) several species and
subspecies (e.g. O. peripherica wasatchensis, O. strigosa cooperi). A complementary goal is to
understand the processes that have led to distributions of Oreohelix lineages in the Western
United States. Here we focus on the Black Hills of South Dakota and Wyoming, a disjunct
portion of the Rockies that appears to isolate mountain snails like Oreohelix due to intervening
unfavorable habitat. We examine lineage diversity within the Black Hills and relationships of
lineages to adjacent populations in Montana and Wyoming. In particular, we examine O.
strigosa cooperi, a subspecies found within the Black Hills that has recently been proposed for
state listing, to determine its uniqueness and extent of isolation.
Genetic Structure of Biomphalaria glabrata Populations
Sampled from a Schistosomiasis Endemic Region
A.R. Wethington1*, M.K. Smith1, G. Oliveira2, F. Lewis3 and D.J. Minchella1
1 Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
aw eth i ng@aol .com
2 Centro de Pesquisas Rene Rachou - FIOCRUZ, Av. Augusto de Limal715,
Belo Horizonte, MG Brazil 30190-002
3 Head, Schistosomiasis Laboratory, Biomedical Research Institute,
12111 Parklawn Drive, Rockville, MD 20852
Seven microsatellite loci were used to genotype 308 Biomphalaria glabrata from 17
populations in Virgem das Gracas (Brazil), a schistosomiasis-endemic area. Snail populations
were sampled from a variety of environments within a 3 kilometer range, and snail genetic
population structure was used to assess gene flow patterns. There was a significant isolation by
distance when comparing In distance with st values. Given the marked genetic structuring of
these populations, gene flow appears to be very low even between geographically close
populations. In general, there was a reduction in the expected number of heterozygotes over all
loci and over most populations, indicating a high level of selfing and/or close inbreeding. This
even occurred in snail populations parasitized by the castrating trematode. Schistosoma mansoni.
Results from this study are important for understanding the potential for local adaptation
between schistosomes and their snail hosts at this epidemiologically relevant scale.
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Phylogenetics of the Genus Isognomon (Bivalvia: Pterioidea):
Initial Findings and Cross-isthmus Invasions
John A. Wilk
Field Museum ofNatural History, 1400 S. Lake Shore Drive, Chicago, IL 60605
i wi lk@fieldmuseum.org
The genus Isognomon is a group of marine, pantropical oysters known for their
multivincular hinge ligaments and extreme plasticity in their shell morphology. This plasticity
often results in continuous grades of shell shapes and has led to much controversy within the
systematics of the group. We have examined soft tissue and stable shell character morphology in
several members of this genus as well as analyzing Cytochrome Oxidase I sequence data for a
smaller subset of this genus. While the analysis of this genus is far from complete, the findings
up to this point shed light on some sub-generic affinities within the genus as well as on the
evolution of the Caribbean species and the Pacific sister taxa from which they arose.
Morphology and Function of Invertebrate Hemocytes:
Physiological Effects of Stress in Aplysia californica
Heather R. Wilkinson and Gary G. Martin
Occidental College, Department of Biology, Los Angeles, CA 90041
HeatherAViikinson@gmail.com
We are interested in how environmental factors affect the physiology and immune
responses of marine invertebrates. Initial work has focused on characterizing the circulating
hemocytes in A. californica. A single type of hemocytes was observed using morphological
techniques (LM, TEM, SEM) and differential centrifugation on metrizoic acid gradients. A
typical hemocyte is ~6 m in diameter with a central nucleus, surrounded by many filopodia.
The cytoplasm contains large amounts of glycogen along with a few granules positive for acid
phosphatase. Hemocytes rapidly adhere to substrates, exposing several large lamellipodia, and
are capable of phagocytosing yeast particles.
Tide pool studies were arranged in order to assess the effect of air exposure on Aplysia.
Hemolymph samples were collected from animals submerged in pools and animals exposed
above the low tide mark. Animals found exposed were placed under water, and submerged
animals were placed out of water for one hour each. Hemolymph samples were withdrawn again
and analyzed for total hemocyte count (THC), blood glucose levels (sigma kit, GAGO-2Q) and
protein concentration (Bradford assay). Preliminary data shows a significant increase in
circulating hemocytes in animals exposed for extended amounts of time, and decreased THC in
submerged animals. Glucose and protein assay results will be described. Further lab studies will
determine if THC, protein and glucose assays are correlated with osmoregulation.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
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A PCR-based Method for Identifying Individual Larvae of Molluscs
Demian A. Willette and Patrick J. Krug
California State University, Los Angeles, CA 90032-8201
defnianwillette@hotmail.com
Taxonomic identification is problematic for mollusc larvae that lack species-specific
morphological characters. We developed a molecular method for identifying gastropod and
bivalve larvae to species or genus. Larvae (130-300 _m) were sampled from southern
Californian estuaries, sorted by gross morphology, photographed and frozen. Genomic DNA
was extracted from individuals or pools of 2-10 morphologically identical larvae. Sequences of
the mitochondrial cytochrome oxidase 1 gene, widely used in genetic studies of invertebrates,
were amplified by polymerase chain reaction (PCR_) and compared to the NCBI database. Larval
species was determined by 99-100% sequence identity over 380-560 base pairs; an 83-92%
match identified the likely genus while indicating that the exact species was missing from the
database. Sequences were obtained from 70% of veligers, half of which were confidently
identified to species. Common veligers included Bulla gouldiana, Haminoea vesicula,
Crepipatella lingulata, and Crepidula onyx. Some veligers with affinity to Echinolittorina or
cephalaspideans could not be identified to genus, highlighting limitations of the public database.
A quarter of pediveliger samples yielded sequences. The most abundant pediveliger in Newport
Bay was the invasive mussel Musculista senhousia which dominated the plankton in September
2004 (1,696 ±614 larvae per m3); other pediveligers had affinity to the invasive clam genus
Corbicula sp. This method should provide information on reproductive seasonality and larval
abundance of invasive bivalves, important for wetland preservation. We are also assembling a
visual key to identified larvae of common species, and developing taxon-specific probes to
improve results for bivalve and polychaete larvae.
Genetics of Sex Ratio Variation in the Apple Snail, Pomacea canaliculata
Yoichi Yusa
Faculty of Science, Nara Women’s University, Nara 630-8506, Japan
vusa@;cc.nara-wu.ac. i p
The population sex ratios in the apple snail Pomacea canaliculata are nearly 1:1, but the
brood sex ratios vary almost continuously from all male to all female. Here I report results of
experiments to study genetics of the sex ratio variation. First, I studied regressions of the
offspring sex ratio on the sex ratios of the parents’ siblings as well as correlations in the brood
sex ratios between sisters or brothers. There were significant positive relationships between the
offspring sex ratio and the sex ratio of the mother’s siblings (slope = 0.28), and between the
offspring sex ratios of two sisters ( r = 0.41). On the other hand, the father-offspring regression
(slope = 0.10) and correlation between two brothers ( r = -0.13) were not significant. These
patterns differed from predictions using typical cytoplasmic sex factors, sex-ratio genes or
polygenic sex determination. Next, I studied the effect of each parent on the brood sex ratio, by
exchanging partners among mating pairs. There were positive correlations between sex ratios of
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 80
half-sib broods of the mother (r = 0.42) and the father (r = 0.47). Moreover, the correlation
between full-sib broods was nearly 1 (r = 0.92). Thus, both parents contributed equally to the sex
ratio variation. The most likely mechanism of the sex ratio variation involves a small number of
nuclear sex-determining genes that act additively.
The Genus Thyasira Leach, 1817 (Lucinoidea: Thyasiridae),
in the Magellan Region and Adjacent Antarctic Waters
Diego G. Zelaya
Museo de La Plata, Division Zoologia Invertebrados, Paseo del Bosque s/n (1900), Buenos Aires, Argentina
dzelava@museo.fenvm.unlp.edu.ar
Thyasira Leach, 1817, is a worldwide genus of infaunal bivalves, occurring from shallow
to abyssal waters, including oxygen-poor and hydrogen sulfide-rich environments. Five species
of the genus were reported from the Magellan Region and adjacent Antarctic waters: Thysira
falklandica Smith, 1885, Thyasira fuegiensis (Dali, 1889), Thyasira magellanica Dali, 1901,
Thyasira bongraini (Lamy, 1910) and Thyasira debilis (Thiele, 1912). At present, there is
confusion on their identity, arising from the unprecise original descriptions, based on few, subtle
and widely variable shell characters. Soft part anatomy of the species is completely unknown. In
this study a revision of the thyasirids occurring in the Magellan Region and adjacent Antarctic
waters is performed by studying shell and gross external anatomy. The study is based on material
collected during several field trips at the Magellan Region and the Scotia Arc Islands. Shell
morphology was studied by SEM and anatomy by dissection under stereoscopic microscopy.
In addition to the five species of Thyasira previously reported for the area, 3 species new
to science were found during this study. Most of the species here examined showed great
intraspecific variability in shell morphology. This fact is in contrast with the soft part anatomy
(e.g. the morphology of the gill and food) that proved to be appropriate to recognize different
species.
The Diversity of Scissurellidae and Anatomidae
in Sub-Antarctic and Antarctic waters: Preliminary Results
Diego G. Zelaya and Daniel L. Geiger
'Museo de La Plata, Division Zoologia Invertebrados,
Paseo del Bosque s/n (1900), Buenos Aires, Argentina
dzelava@museo.fcnvm.unlp.edu.ar
2Santa Barbara Museum of Natural History, 2559 Puesta del Sol Road, Santa Barbara, CA 93105
Scissurella and Anatoma are two genera of worldwide distribution classified in Mollusca,
Vetigastropoda, occurring from the intertidal to abyssal depth. Twelve nominal species of these
genera were described from Sub-Antarctic and Antarctic waters: Scissurella conica d’Orbigny,
1841, S', supraplicata Smith, 1875, S. obliqua Watson, 1886, S. dalli Bartsch, 1903, S. euglypta
Pelseneer, 1903, S. clathrata Strebel, 1908, S. petermannensis Lamy, 1910, S. eucharista Melvill
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 8 1
& Standen, 1912, S. timora Melvill & Standen, 1912, S. amoena Thiele, 1912, Schismope
subantarctica Hedley, 1916 and S. medioplicata Thiele, 1925. The species are of small size
(0.8-2. 5 mm) and have intricate sculpture by which species and genera are distinguished, yet all
species were described before the invention of the scanning electron microscope. Thus, the
proper placement and systematic affinity are unresolved in several instances. The objective of
this study is to provide some preliminary results on the systematic revision of scissurellids and
anatomids from Sub-Antarctic and Antarctic waters.
This study is based on the material collected during several field trips to the Magellan
Region and the Scotia Arc Islands, and museum collections. Shell and radula morphology is
studied by SEM; anatomical studies are based on dissections under stereoscopic microscopy and
histology.
Preliminary results suggest the presence of several synonymies and erroneous application
of generic names, because of the inadequacy of old observational techniques (most species were
described only from stereoscopic microscope observations) or the poor condition of the studied
materials (masking for example the protoconch morphology).
Federal Efforts to Exclude Snails and Slugs
Associated with Agricultural Imports
Frederick J. Zimmerman
United States Department of Agriculture, Animal and Plant Health Inspection Station,
Plant Protection and Quarantine, Miami, Florida 33159
Frederick.Zimmerman@APHlS.USDA.GOV
At ports of entry in the United States some agricultural cargo, carriers, mail, and baggage
are inspected to detect unwanted snails, slugs and other pests. Federal permit and phyto-sanitary
inspection requirements strive to allow entry only to pest-free, non-prohibited agricultural cargo.
Even with the multi-faceted federal inspection activities that are in place, the potential for new
mollusk pest introductions will be ever present, and when combined with the invasive mollusk
pests already present, America’s native malacofaunas as well as the agricultural, hydrological,
economic and other resources, remain at risk.
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 82
CONTRIBUTED PAPER
Editors' Note: Because of timing coincidences, this report on the August 2009 meeting of the
Sociedad Mexicana de Malacologia can be included in this Annual Report of the 38th meeting of
the Western Society of Malacologists. The two societies will hold a joint international meeting
in June 201 1, at La Paz, Baja California Sur, Mexico, under the Presidency of Esteban Felix
Pico. Mark your calendars and plan to attend this significant bilingual scientific interchange.
XI Reunion de la Asociacion Nacional de Malacologia y Conquiliologia (XI REN AM AC):
a Report on the August 2009 Meeting
Hans Bertsch1 and Esteban Felix Pico2
‘Departamento de Ingenieria en Pesqueria,
Universidad Autonoma de Baja California Sur, La Paz, BCS, Mexico
192 Imperial Beach Blvd. #A, Imperial Beach, CA 91932
hansmarvida@sbcglobal.net
2Centro Interdisciplinary de Ciencias Marinas (CICIMAR-IPN),
A.P. 592, La Paz, Baja California Sur, C.P. 23096, Mexico
efelix@jpn.mx
The National Mexican Association of Malacologists and Conchologists held its eleventh
annual meeting in the Centro Intemacional de Vinculacion y Ensenanza on the lakeside campus
of Universidad Juarez Autonoma de Tabasco (UJAT), 24-28 August 2009. Dr. Luis Jose Rangel
Ruiz (Laboratorio de Malacologia, Division Academica de Ciencias Biologicas) was the gracious
host President. Institutional hosts of this meeting were UJAT, Sociedad Mexicana de
Malacologia A.C. (SMMAC), and the Comision Nacional para la Biodiversidad (CONABIO),
with additional support from the Secretaria de Turismo del Estado de Tabasco.
The meeting involved over 65 participants from 4 countries and at least 12 states of
Mexico (Figure 1). There were representatives from 1 1 official institutions, with a huge range of
ages, experience, background and professional expertise. The event had one day of four pre-
conference workshops, 3 days of conferences, and a one-day field trip to view the fauna and flora
of local rivers, ranchlands and jungles, and the Mayan archaeological ruins of La Palenque in the
adjacent state of Chiapas.
Workshops and Presentations
Workshops emphasized the practical, ecological and theoretical: “Biotechnology of
Bivalve Cultivation” (by Esteban Felix Pico of Baja California Sur), “Introduction to the
Geometric Morphology of Molluscs” and “Preparation of Manuscripts for Scientific Publication”
(by Roberto Cipriani of Venezuela), and “Theories of Oyster Cultivation: Basic Principles” (by
Andres Gongora Gomez of Sinaloa).
Themed sessions of papers addressed archaeology and paleontology, biodiversity,
ecology, biology, biogeography, collections, conservation and contamination, taxonomy and
systematics, reproduction and genetics, and cultivation. There were 54 oral conferences and 14
posters, with exhibits of 3 mollusc collections.
Appropriately, conference presentations were held in mollusc-named rooms, Sala “Tote”
(= Pomacea flagellata , Mexico's largest freshwater snail) and Sala “Shutti” (= Pachychilus
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 83
chrysalis, a FW snail of Tabasco and Chiapas, eaten by local residents).
Of particular interest to one of us (HB), were the opisthobranch presentations on Yucatan
biodiversity and biogeography (Jazmin D. Ortigosa Gutierrez, N. Simoes & G. Calado);
biodiversity of Estero de Urias and the Mazatlan coastline (Christian Samuel Castillo Flores, M.-
A. Ortiz Arellano, J. C. Roman Reyes & M. Nieves Soto); provincial level biogeography, from
Point Conception, California, to Punta Aguja, Pern (FIB); holdings in the Coleccion Nacional de
Moluscos (Andrea Zamora & Edna Naranjo Garcia); a new species of tritoniid, the first known to
feed on zoanthids, not alcyonarians (H. Bertsch, A. Valdes & T. M. Gosliner); and the
systematics and phylogeny of Navanax and the Aglajidae (Andrea Zamora).
Student posters were remarkably well done, and the judging committee praised them all
when announcing the prize winners (Figure 2). First place poster award was shared for “Fauna
Malacologica con Enfasis en Micromoluscos de Isla Socorro, Archipielago de Revillagigedo,
Colima, Mexico” (by Isaura Rebeca Zamora Lopez and Brian Urbano Alonso) and
“Malacolofauna Asociada a Substrato Coralino de Majahual, Quintana Roo, Mexico” (by Iris
Dinora Garcia Tello, Jorge Luis Garces Salazar and V. Solis Weiss). Second and third place
awards were presented respectively for “Bivalvos de Mexico en la Coleccion Malacologica 'Dr.
Antonio Garcia Cubas'” (by Orquidea Lozada Flores and Martha Reguero Reza) and “Diversidad
de Opistobranquios del Litoral de Acapulco, Guerrero, Mexico” (by Berenice G. Martinez
Vazquez, Pedro Flores Rodriguez, Rafael Flores Garza and Sergio Garcia Ibanez).
Field Trip to Palenque ( Lakanha = Agua Grande, Big Water)
Reunion participants were offered a selection of field trips to various cultural and
touristic sites in the city of Villahermosa and the surrounding areas. About a dozen of us toured
the incredible (and only partially excavated) Mayan ruins of Palenque, in the adjacent state of
Chiapas. Our guide was bilingual in Mayan and Spanish, and provided us with intriguing
information about the names, uses, and significance of the various temples and administrative
buildings that we scrambled over, under and through!
The stone walls were covered originally with a seashell-based stucco, painted with hues
of red, blue, yellow, green and ochre. We were astounded at the inestimable tons of oyster and
other marine shells that had been collected, crushed and processed for the buildings' outer layers,
Palenque (founded -150 B.C.E, abandoned -900 C.E.) reached it apogee as a regional
center in the Usumacinta river basin from 600-800 C.E., due in large measure to the efforts of
K'inich Janaab' Pakal, who ruled from his 12 birthday for 68 years (remember that the Mayans'
average lifespan was only 37 years). Pakal constructed the hugely grandiose Templo de las
Inscripciones surrounding and enclosing the 6.93 m3, thirteen-ton sarcophagus (carved from a
monolithic stone block) in which he would be buried. Archaeologists named this 21 meter high
pyramidal edifice “The Inscriptions,” because of the 617 interior wall glyphs which describe the
divine rights of kings, their relations with the gods and their inherited privileges, and dated
reports of important events during Lakanha's history.
Still partially overgrown by the rain-fed tropical forest, the plaza and buildings named
Grupo de las Cruces (or Plaza del Sol) form an architectural calendar, built on a world axis, east-
west alignment (Figure 2). We climbed the 21-stepped entranceway of Templo del Sol,
dedicated to the Sun (Lord of War) and the Jaguar (Lord of the Underworld), examining the
painted glyph on the western inner wall of the sanctuary. Only the dawning equinox sunrise
stabs it with light.
Palenque's late discovery by the Spaniards in the mid- 1700s had protected it from the
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 84
zealot-driven cultural destruction wrought by a conquering foreign government and religion in
the early 1500s. Continuing excavations, decipherment of glyphs, and archaeozoologic and
ethnographic studies will provide a better understanding of this culture's interrelationships with
their marine and terrestrial environments, and among themselves. The Classic Mayans' intensive
collection and use of marine molluscs may help develop modem methods of sustainable clam
cultivation and production, a common theme among many of the XI REN AM AC presentations.
Joint Meeting Announcement, 2011
The XII RENAMAC will be held in June 2011, in La Paz, Baja California Sur, jointly
with the 44th Annual Meeting of the Western Society of Malacologists. The coinciding
President for both societies will be Esteban Felix Pico. Already being planned are an all-day
Symposium on the History of Malacology in Baja California and, of course, field trips by land
and sea to research molluscs ecologically in situ or in delicious repasts.
This will be the second meeting of the WSM in this pearl-laden peaceful city on the
shores of the southern Gulf of California. Our Society's 40th meeting was held there, under the
Presidency of Dr. Carlos Caceres Martinez, and detailed in WSM Annual Report (March 2009)
for 2007, vol. 40, and Bertsch, 2007, The Festivus 39: 97-100. Research in the region by WSM
charter members A. Myra Keen and Allyn G. Smith (e.g., their 1961 publication on the bivalve
sacoglossan opisthobranch Berthelinia) may have presaged our Society's recent presence in La
Paz.
Figure 1. Group photograph (courtesy SMMAC).
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 85
Figure 2. Student poster award winners and professors (from left to right). Back Row: Dr.
Esteban Felix Pico, Berenice Grisel Martinez Vazquez, Julio Magana Cubillo, Dra. Martha
Reguero Reza, Dr. Hans Bertsch, Orquidea Lozada Flores, and Jazmin Deneb Ortigosa Gutierrez.
Middle Row: Dr. Luis Jose Rangel Ruiz, Dr. Roberto Cipriani, Ana Maria Rivera, Brian Urbano
Alonso, Isaura Rebeca Lopez, Iris Dinorah Garcia Tello, and Jorge Luis Garces Salazar. Front
Row: Jaquelina Gamboa Aguilar, Dr. Luis Alfonso Rodriguez Gil, Dra. Edna Naranjo Garcia, and
Andrea Zamora. (Photo by Rosa del Carmen Campay. We thank Luis Jose Rangel Ruiz and
Jacquelina Gamboa Aguilar for providing the names of the student poster award winners.)
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 86
Figure 3. Members of XI RENAMAC at the Templo del Sol (an equinox archaeoastronomical site),
Mayan ruins of La Palenque, Chiapas (from left to right). Standing: Esteban Felix Pico, Blanca E.
Buitron Sanchez, Miguelina Morales Garcia, J. Emilio Michel Morfin, Martha Reguero Reza,
Roberto Cipriani, Lilia Y. Rendon Diaz, Edgar Heimer de la Cotera, Luis Alfonso Rodriguez Gil, and
Our Guide. Kneeling: Catalina Gomez Espinosa and Rosa del Carmen Campay. (Photo by Hans
Bertsch)
Western Society of Malacologists Annual Report for 2005, v. 38 (2010)
Page 87
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