QL401 . W47 V. 36/37 2003/2004 THE WESTERN SOCIETY OF MALACOLOGISTS ANNUAL REPORT FOR 2003/2004 VOLUMES 36/37 IN MEMORIAM David K. Mulliner 15 April 1921--24 January 2007 Founding Member and First President, WSM, 1968 25th President, WSM, 1992 THE WESTERN SOCIETY OF MALACOLOGISTS ANNUAL REPORT FOR 2003/2004 VOLUMES 36/37 THE WESTERN SOCIETY OF MAEACOLOGISTS ANNUAL REPORT For 2003 Volume 36 Abstracts and Papers from the 36th Annual Meeting of the Western Society of Malacologists held in Los Angeles, California, June 6-10, 2003 June 2007 Officers of the Western Society of Malacologists for 2003 President Vice President Second Vice President Secretary Treasurer Members at large Angel Valdez George Caceres Peter Roopnarine Cynthia Trobridge Terry Arnold George L. Kennedy Edna Naranjo Garcia Webmaster Douglas J. Eemisse Committees and Appointments Editorial Board for Volumes 36/37 Nora R. Foster (Editor) Hans Bertsch Student Grant Committee Lindsey Groves Douglas J. Eemisse Daniel Geiger Sandra Millen Peter Roopnarine Western Society of Malacologists Annual Report, Vol. 36, p 2 TABLE OF CONTENTS Volume 36 I. ECOLOGY SYMPOSIUM Organized by Jeff Goddard 6 Using trace element concentrations in mytilid mussel shells to determine larval sources B. J. Becker, L. Levin, P. Mcmillan, and F. J. Fodrie 6 Diet-specificity in sponge-feeding nudibranchs from Cape Arago, Oregon Jeff Goddard 6 Restored marshes with tidal pools in San Francisco Estuary yield common, ancient gastropods, other aquatic invertebrates, and their predatory fishes Christopher L. Kitting and C. L. Davis 7 Cryptic impacts of invasive species: Parasites of sympatric native and introduced snails Mark E. Torchin, James E. Byers, and Todd C. Huspeni 8 Japanese sacoglossan opisthobranchs associated with Codium spp. (Chlorophyta) Cynthia D. Trowbridge, Yoshiaki J. Hirano, and Yayoi M. Hirano 9 Rock and coral boring Bivalvia (Mollusca) of the Middle Florida Keys, USA Paul Valentich-Scott and Grete Elisabeth Dinesen 9 Where does the escargot? Molluscan statoliths and protoconchs as natural tags of natal origin Danielle C. Zacherl 10 II. PALEONTOLOGY SYMPOSIUM Organized by Lindsey Groves 10 New species of Late Cretaceous cypraeids (Mollusca: Gastropoda) from Califomina and British Columbia Lindsey T. Groves 1 0 A new species of Miocene Zonaria (Mollusca: Gastropoda: Cypraeidae) from central Chile and its biogeographic significance Lindsey T. Groves and Sven N. Nielsen 13 Paleontology and geochronology of the middle and upper Pleistocene marine record in the downtown San Diego area, San Diego County, southern California George L. Kennedy and Ian D. Browne 1 3 Paleontology of new middle Eocene faunas and floras from northern San Diego County, southern California George L. Kennedy, Jeffrey A. Myers, Stephen L. Walsh, and Ian D. Browne 35 Volutoderminae (Gastropoda, Volutidae) from the Late Cretaceous of the Pacific slope of North America LouElla R. Saul and Richard L. Squires 35 Paleontologic record of the pseudomelaniid gastropod Trajanella from the marine Cretaceous of the Pacific slope of North America Richard L. Squires and LouElla R. Saul 36 Western Society of Malacologists Annual Report, Vol. 36, p 3 Overview of Late Cretaceous marine gastropods from the Chatsworth Formation, Simi Hills, Southern California Mary Stecheson 37 III. PHYLOGENETICS SYMPOSIUM Organized by Doug Eemisse 40 Genetic signatures of patellogastropod dispersal Emina Begovic 40 Octopod molecular phylogeny Cendrine Hudelot and F. G. Hochberg 42 Host choice and genetic divergence in sacoglossan populations Patrick J. Krug 42 Comparative phylogeography of two eastern Pacific eelgrass mollusks - Taylor’s seahare (Phyllaplysia taylori) and the painted limpet (Tectura depictd) Kristina D. Louie and David K. Jacobs 42 The role of molecules in understanding molluscan evolution Monica Medina 43 So what is a species anyway? - A phylogenetic approach using cowries Christopher P. Meyer 43 IV. OPISTHOBRANCH SESSION Reports from the field: Bridging the gap between recreational scuba divers and scientists Mary Jane Adams 44 The genus Armina (Gastropoda: Nudibranchia: Arminidae) in the western Atlantic: New species and a phylogenetic analysis Nestor E. Ardila and Angel Valdes 44 Biogeographic patterns of opisthobranch mollusks in the Gulf of California: Dispersion or vicariance? Orso Angulo Campillo 45 Temporal and spatial variations of the Opisthobranch Fauna near La Paz, Baja California Sur, Mexico Orso Angulo Campillo, Juan Elorduy Garay, and Hans Bertsch 46 Preliminary phylogeny of the genus Thordisa Bergh, 1877 (Discodorididae, Doridacea, Nudibranchia) with descriptions of six new species Jamie M. Chan 46 Phylogeny of Halgerda (Mollusca: Gastropoda) contrasting mitochondrial DNA (COI) and morphology Shireen Fahey 47 Systematics and phylogeny of the nudibranch genera Okenia and Hopkinsia Terrence M. Gosliner 47 Toward a phylogeny of chromodorid nudibranchs: Which questions can COI help answer? Rebecca F. Johnson 48 The nudibranch family Eubranchidae from the eastern Pacific Sandra Millen, Michael Schrddl, and Alicia Hermosillo-Gonzales 49 The systematics of Roboastra Bergh, 1877 (Nudibranchia, Polyceridae, Nembrothinae) Marta Pola, Juan Lucas Cervera, and Terrence M. Gosliner 49 Western Society of Malacologists Annual Report, Vol. 36, p 4 V. GENERAL SESSION 50 Biodiversity and biogeography of upper slope and continental shelf epifaunal molluscan assemblages from the Caribbean Sea Nestor E. Ardila 50 Comments on malacological research in the Gulf of California, Mexico Hans Bertsch 51 Recent cultured Chinese fresh water pearls of various shapes please pearl buyers and sellers in America Beatrice Burch 5 1 Withering syndrome in abalone from Baja California, Mexico Jorge Caceres-Martmez 58 Reproductive cycle of the Japanese Oyster Crassostrea gigas cultured in Bahia Falsa, Baja California, Mexico Jorge Caceres-Martinez, Rebeca Vasquez- Yeomans, Sergio Curiel-Ramirez Gutierrez, and Patricia Macias Montes de Oca 59 Phenotypes of the California Mussel, Mytilus californianus Conrad (1837) Miguel A. del Rio-Portilla, Jorge Caceres-Martinez, Sergio Curiel-Ramirez Gutierrez, and Ignacio Mendez Gomez Humaran 59 Life history traits and reproductive behavior in Ariolimax spp. (Arionidae: Stylommatophora) Janet L. Leonard, Erica Mendieta, and John S. Pearse 60 Status report on: “Shell-bearing Gastropoda of the Northeastern Pacific” James H. McLean 61 To chew or eschex — apophallation in Ariolimax as a result of sexual conflict? Brooke Miller 62 Some families of “prosobranch” Mollusca from Mexico Edna Naranjo-Garcia 63 Presence of giant polymorphic cells in Crassostrea gigas cultured in Bahia Falsa, Baja California, NW Mexico Rebeca Vasquez- Yeomans and Jorge Caceres-Martinez 63 VI. POSTER SESSION 64 Beginnings of a new book on the marine bivalve mollusks of Tropical West America Eugene V. Coan and Paul Valentich-Scott 64 The History of the Western Society of Malacologists Jody Woosley and Barbara Chaney 64 Shell-bearing Gastropoda of the Northeastern Pacific James H. McLean 65 VII. REPORTS OF SOCIETY BUSINESS 68 Executive Board Meetings, 6-10 June 2003 68 Annual Business Meeting 70 Group Photograph, WSM Annual Meeting 72 Paleontology Group Photograph 73 Individual Mambership, 2003 74 Institutional Mamberships, 2003 77 Western Society of Malacologists Annual Report, Vol. 36, p 5 1. ECOLOGY SYMPOSIUM Organized by Jeff Goddard University of California, Santa Barbara Using trace element concentrations in mytilid mussel shells to determine larval sources B. J. Becker', L. Levin^, P. Mcmillan^, and F. J. Fodrie^ ‘ Cabrillo National Monument (NPS), Scripps Institution of Oceanography, Mail Code 0208 La Jolla, CA 92093-0208, USA. ^ Scripps Institution of Oceanography, Mail Code 0218, La Jolla, CA 92093-0218, USA. Elemental fingerprinting utilizes a tag naturally found in the environment, such as trace elements or temperature and salinity signals, to track movements of animals. The chemical composition of newly formed calcium carbonate structures strongly reflects many aspects of the seawater environment in which it is precipitated. If the conditions are sufficiently different at nearby locations and hard parts are retained after settlement, it is possible to determine from where new mollusk settlers came by analyzing the chemical composition of the larval shells they formed earlier in their lives. We are developing a technique to analyze the chemical composition of mussel (Mytilus galloprovincialis and M californianus) shells collected in San Diego County, California (USA) for larval tracking purposes. We are able to analyze the solid shell directly using laser ablation and a high-resolution ICP-MS, in order to determine composition on a small scale (20-40 microns). We are therefore able to study multiple elemental fingerprints on the same shell, representing various periods in the development of the individual. In order to verify the validity of the method, we first must determine if signals are significantly different on an appropriate spatial scale to differentiate between larvae from different sites. In addition, the temporal variability of this signal must be defined. We analyzed samples from multiple sites (at the same time) and from multiple times (at the same site) in order to determine the spatial variability and temporal stability of the signal. The next step is to use this method to determine larval sources. Long-term goals include determination of degree of self-seeding in a local marine reserve and the amount of exchange between bays and the open coast populations. Diet-specificity in sponge-feeding nudibranchs from Cape Arago, Oregon Jeff Goddard Marine Science Institute, University of California, Santa Barbara, CA 93106, E-mail: goddard@lifesci.ucsb.edu Eudoridacean nudibranchs are specialized predators of sponges in marine benthic communities. Few studies have examined prey use in local assemblages of dorids, and little is known about how their diets and host-use vary geographically and by habitat. I studied diet specialization and overlap in eudoridaceans (excluding Rostanga pulchra, a small dorid which Western Society of Malacologists Annual Report, Vol. 36, p 6 preys exclusively on encrusting red-orange sponges) in intertidal cobble fields on the protected outer coast at Cape Arago, Oregon. I determined diets by direct observation of feeding in the field and by microscopic examination of sponge spicules in the fecal strands or gut contents of specimens isolated at collection. To determine dietary overlap I calculated coefficients of similarity using the Bray-Curtis Index and the frequency of each dorid species feeding on each sponge. To compare the observed diets with prey preferences, I conducted pair-wise chemosensory experiments using a chamber with directional, turbulent mixing in the main test arena of the two source flows. I obtained 515 prey records for nine species of dorids. Hallaxa chani, Aldisa sanguinea and Geitodoris heathi were the most specialized and consumed only one species each {Halisarca sp., Hymedesmia sp. and Mycale macginitei, respectively), while Cadlina luteomarginata and Diaulula nobilis were the most generalized and consumed 12 and 17 species, respectively. The results of the chemosensory experiments generally matched the observed diets, with the conspicuous exception of the significant preference of Archidoris odhneri for Halichondria panicea over Hymeniacidon ungodon, the sponge on which it was usually found feeding in the field. Diet overlap between species ranged from 0 to 49%, with a mean of 6%. It was greatest between Cadlina modesta and C. luteomarginata (49%) and C. luteomarginata and Diaulula nobilis (28%). Bloom (1981) reported a mean dietary overlap of 46% for six species of eudoridaceans in the San Juan Archipelago. Mean diet overlap for the same six species at Cape Arago was 7%. With the exception of Geitodoris heathi, which preyed on a single species at Cape Arago and was reported by Bloom (1981) to consume eight species in the San Juans, dietary specialization (measured as both species richness and diversity of prey) was similar for each of these species at both sites. Reduced dietary overlap at Cape Arago likely reflects the higher species richness of sponges on the outer coast at Cape Arago, compared to the inland waterways of the San Juan Archipelago. References Bloom, S. A. 1981. Specialization and noncompetitive resource partitioning among sponge- eating dorid nudibranchs. Oecologia 49:305-315. Restored marshes with tidal pools in San Francisco Estuary yield common, ancient gastropods, other aquatic invertebrates, and their predatory fishes Christopher L. Kitting and C. L. Davis Department of Biological Sciences, and Shore Laboratory, California State University Hayward, CA 94542, USA E-mail; chris.kitting@csueastbay.edu; cldavisl08@yahoo.com We have extensively compared populations of aquatic animals in seven restored and historical brackish marshes around southern Suisun Bay of San Francisco Estuary. Kayaks provided access to narrow tidal creeks and shallow-water marshes largely isolated from previous research. Non-destructive seasonal sampling included -four replicate refugia traps (modified mesh minnow traps,) each representing a total area of 1 m^, near vegetation. Common aquatic animals Western Society of Malacologists Annual Report, Vol. 36, p 7 including amphipods, isopods, and gastropods, and fishes as predators, were abundant in several restored marshes compared with reference marshes. Only sites with marsh tidal ponds yielded numerous aquatic animals. Those restored brackish marshes yielded the most abundant fish populations, and unusual, thriving hydrobiid snails 5 mm long, a close relative of California’s endangered brackish water snail. The unusual snail apparently is Hydrobia andersoni, previously known only from fossils on this ancient San Joaquin River. Sediment cores in the marsh repeatedly yielded these shells over 130 cm deep. Slow sedimentation rates in these isolated marshes suggest a probable age of >~200 years for shells at this depth, indicating that these snails are natives. Subsequent mini-quadrat sampling at the older restoration site yielded high densities of snails, -200 per 25 cm in the mud’s surface and -60 per 25 cm on Ruppia widgeongrass and Enteromorpha green algae. Marsh tidal pools connected to tidal creeks seem very important in restoring ancient populations of estuarine predators and prey animals, possibly overlooked previously in these isolated marsh habitats, previously too difficult to reach and difficult to sample properly. Cryptic impacts of invasive species: Parasites of sympatric native and introduced snails Mark E. Torchin', James E. Byers^, and Todd C. Huspeni' ' Marine Science Institute and Department of Ecology, Evolution and Marine Biology University of California, Santa Barbara, CA 93106 E-mail: torchin@lifesci.ucsb.edu; huspeni@Iifesci.ucsb.edu ^ Department of Zoology, University of New Hampshire, 46 College Road, Durham, NH 03824 E-mail: jeb.byers@unh.edu Species introduced to new environments without the parasites that infect them in their native range may experience a performance advantage relative to both conspecifics in the native range, and to more heavily parasitized native competitors. Additionally, introduced species that bring parasites with them may exert unforeseen, broader impacts on native ecosystems. We assessed the role of parasites in a marine invasion by first examining regional patterns of trematode parasitism in the introduced Japanese mud snail, Batillaria attramentaria (= B. cumingii), throughout nearly all of its introduced range in North America. We recovered only one parasite species, which was itself a non-native species, Cercaria batillariae. The prevalence of this introduced trematode in its snail host was highly variable, ranging from 3 to 86%. To determine if parasites were potentially important in mediating the invasive snail’s competitive displacement of a native sympatric mud snail, Cerithidea californica, in Bolinas Lagoon, California we quantified diversity and prevalence of parasites in both snail hosts. Prevalence of larval trematodes infecting snails as first intermediate hosts was not significantly different (14% in B. attramentaria versus 15% in C. californica). However, while the exotic snails were parasitized only by one introduced trematode species, the native snails were parasitized by ten native trematode species. Furthermore, only the native C. californica was infected as a second intermediate host, by Acanthoparyphium spinulosum (78% prevalence). Given the high host specificity of trematodes for first intermediate hosts, in marshes where B. attramentaria is competitively excluding C. californica, 10 or more native trematodes will also become locally Western Society of Malacologists Annual Report, Vol. 36, p 8 extinct. Because of the obligate multi-host life cycle of these trematode species, their loss will likely affect life histories, population dynamics, and fitness of several native estuarine species. Japanese sacoglossan opisthobranchs associated with Codium spp. (Chlorophyta) Cynthia D. Trowbridge,'’^’ Yoshiaki J. Hirano,^’^’ and Yayoi M. Hirano^’^ ’ Hatfield Marine Science Center, Oregon State University, Newport, OR 97365 E-mail: trowbric@onid.orst.edu ^ Misaki Marine Biological Station, University of Tokyo, Japan 3 Kominato Marine Laboratory, Chiba University, Japan Diverse and abundant populations of sacoglossan opisthobranchs inhabit Japanese rocky shores. The species of sacoglossans that feed on the green macroalgae Codium spp. were investigated in Sagami Bay on the Pacific coast of Honshu, Japan. On the Miura Peninsula (eastern side of Sagami Bay), three sacoglossan species were particularly abundant: Elysia trisinuata Baba, 1949, E. setoensis Hamatani, 1968, and Placida sp. Baba, 1986. Phenology, population dynamics, and algal host use of these species are described based on numerous short- term visits to Misaki Maine Biological Station (MMBS) between 2000 and 2003 and the literature. Elysia trisinuata grows substantially larger than sympatric sacoglossans on Codium with maximum weight ca. 750 mg. This sacoglossan spawned in spring, and small juveniles appear on algal hosts in summer. Juvenile slugs fed on at least three Codium spp., whereas adult conspecifics are presumed to rely largely on functional kleptoplasty. The congener E. setoensis was quite abundant on C. fragile in summer but did not form feeding aggregations or cause extensive grazing damage. Finally, Placida sp. was small, seasonally abundant on algal hosts, and often caused visible grazing damage. These sacoglossan species frequently coexisted on algal hosts, particularly C. fragile. Interspecific interactions appeared to be minor with no discernible interference or exploitation competition. There was no evidence that these Japanese sacoglossans controlled the population abundance and distribution of their Codium hosts. Rock and coral boring Bivalvia (Mollusca) of the Middle Florida Keys, USA Paul Valentich-Scott and Crete Elisabeth Dinesen ' Department of Invertebrate Zoology, Santa Barbara Museum of Natural History 2559 Puesta del Sol Road, Santa Barbara, California 93105 E-mail: pvscott@sbnature2.org University of Aarhus, Institute of Biological Sciences, Department of Marine Ecology, Finlandsgade 14, DK-8200 Aarhus N, Denmark E-mail: Grete.Dinesen@biology.au.dk Eight species from three bivalve families were collected and/or observed in the Middle Florida Keys. Diagnoses based on shell characters are given for Botula fusca, Lithophaga antillarum, L. aristata, and L. bisulcata in the Mytilidae, and Gastrochaena hians in the Gastrochaenidae. Shell and anatomical comparisons are made for three members of the Western Society of Malacologists Annual Report, Vol. 36, p 9 Petricolidae, Petricola lapicida, Choristodon robustum, and Choristodon sp. A, which is not attributable to a described Recent Choristodon species. These bivalves bore into limestone and dead coral, and in one case into living coral. Observations substantiated previous hypotheses of primary chemical boring processes in Botula and Petricola. Where does the escargot? Molluscan statoliths and protoconchs as natural tags of natal origin Danielle C. Zacherl University of California, Los Angeles, Los Angeles, CA 90095 E-mail: zacherl@ucla.edu The management of commercially important marine invertebrates requires knowledge about larval dispersal pathways, yet no effective means exist to track invertebrate larvae in the plankton from source to settlement location. Mineralized hard parts (e.g., statoliths, protoconchs, carapaces, and larval skeletons) formed at the source of larval production potentially record a natural tag of a larva’s origin in their elemental composition; they represent a new tool for tracking larval movements. I examine the utility of protoconchs and statoliths as markers of natal origin in the marine neogastropods Kelletia kelletii and Concholepas concholepas, and in the estuarine opisthobranch Alderia modesta. Data generated from controlled laboratory culturing experiments suggest larval statoliths and protoconchs meaningfully record variation in seawater physical and chemical properties. Survey data demonstrate that larval hard parts formed at geographically separated oceanic coastal sites show distinct chemical signals. Together, these data suggest larval statoliths and protoconchs can be powerful new tools for tracking dispersal pathways and identifying source populations. 11. PALEONTOLOGY SYMPOSIUM Organized by Lindsey Groves Natural History Museum of Los Angeles County New species of Late Cretaceous cypraeids (Mollusca: Gastropoda) from Californina and British Columbia Lindsey T. Groves Natural History Museum of Los Angeles County, Malacology Section, 900 Exposition Boulevard, Los Angeles, CA 90007 E-mail: lgroves@nhm.org Cretaceous cypraeids are rare in North American strata and comprise 15 recognized species (Groves, 1990). Four new species will be described from localities in southern and northern Western Society of Malacologists Annual Report, Vol. 36, p 10 California and British Columbia. These new species include two species of Bernaya s.s., a single species of Bernaya (Protocypraea), and a single species of Palaeocypraea s.s. The new species are as follows: Bernaya n.sp. 1 from the Upper Cretaceous (lower Campanian), Chico Formation, Butte County, California; Bernaya n.sp. 2 from the Upper Cretaceous (upper Santonian/lower Campanian), Haslam Formation, Vancouver Island, British Columbia; Bernaya {Protocypraea ) n.sp. from the Upper Cretaceous (lower Campanian), Chico Formation, Butte County, California; and Palaeocypraea s.s n.sp. from the Upper Creatceous (lower Santonian/lower Campanian), Chico Formation, Butte County, California. The Campanian/Maastrichtian is the Mesozoic peak in terms of both numbers of species and geographic distribution both in North America and worldwide (Groves, 1994). CRETACEOUS CYPRAEOIDEANS OF NORTH AMERICA EARLY CRETACEOUS (1 species) Albian [I species] Cypraeidae Palaeocypraea (Palaeocypraea) fontana (Anderson, 1958): Shasta Co., California LATE CRETACEOUS (18 species) Turonian [3 species] Cypraeidae Bernaya (Protocypraea) berryessae (Anderson, 1958): Yolo Co., California B. (P.) argonautica (Anderson, 1958): Jackson Co., Oregon Ovulidae Eocypraea (Eocypraea) louellae Groves, 1990: Yolo Co., California & Jackson Co., Oregon Campanian [8 species] Cypraeidae Palaeocypraea (Palaeocypraea) suciensis (Whiteaves, 1895): San Juan Co., Washington Palaeocypraea (P.) n.sp.: Chico Fm., Butte Co., California B. (B.) burlingtonensis (Schilder, 1932): Burlington Co., New Jersey B. (B.) n.sp. 1: Chico Fm., Butte Co. & Placer Co., California B. (B.) n.sp. 2: Haslam Fm., Vancouver Id., British Columbia Bernaya (Protocypraea) mississippiensis Groves, 1990: Lee Co., Mississippi B. (P.) n.sp.: Ladd Fm., Orange Co., California Western Society of Malacologists Annual Report, Vol. 36, p 1 1 Ovulidae Eocypraea (Eocypraea) morloni (Gabb, 1860): Wilcox Co., Alabama Maastrichtian [7 species] Cypraeidae Palaeocypraea (Palaeocypraea) corsicanana (Stephenson, 1948): Navarro Co., Texas P. (P.) grooti (Richards & Shapiro, 1963): New Castle Co., Delaware P. (P.) nuciformis (Stephenson, 1941): Kaufman Co., Texas P. (P.) squyeri (Campbell, 1893): Wibaux Co., Montana B. (Bernaya) crawfordcatei Groves, 1990: San Diego Co. & Orange Co., California Bernaya (Protocypraea) gualalaensis (Anderson, 1958): Mendocino Co. & San Diego Co., California B. (P.) rineyi Groves, 1990: San Diego Co., California References Anderson, F.M. 1958. Upper Cretaceous of the Pacific coast. Geological Society of America, Memoir 71 : 1-378, figs. 1-3, pis. 1-75. Campbell, J.H. 1893. Description of a new fossil Cypraea. The Nautilus 7(5):52, pi. 2, figs. 1-2. Gabb, W.M. 1860. Descriptions of new species of American Tertiary and Cretaceous Fossils. Journal of the Academy of Natural Sciences of Philadelphia, 2nd ser., 4:375-406, pis. 67-69. Groves, L.T. 1990. New species of Late Cretaceous Cypraeacea (Mollusca: Gastropoda) from California and Mississippi, and a review of Cretaceous cypraeaceans of North America. The Veliger 33(3):272-285, figs. 1-34. Groves, L.T. 1994. Jurassic and Cretaceous cypraeacean biogeography and paleontology with an annotated list of the species. The Cowry n.s. 1(2):25-41, figs. 1-20. Richards, H.G. & Shapiro, E. 1963. An invertebrate macrofauna from the Upper Cretaceous of Delaware. Delaware Geological Survey, Report of Investigation 7:1-37, figs. 1-3, pis. 1-4. Schilder, F.A. 1932. Cypraeacea. In: Quenstedt, W. (ed.), Fossilium Catalogus I: Animalia, W. Junk, Berlin. 55:1-276. Stephenson, L.W. 1941. The larger invertebrate fossils of the Navarro Group of Texas. University of Texas Publication 4101:1-641, pis. 1-95. Stephenson, L.W. 1948. Cypraea corsicanana, new name for Cypraea gracilis Stephenson, preoccupied. Journal of Paleontology 22(5):642. Western Society of Malacologists Annual Report, Vol. 36, p 12 Whiteaves, J.F. 1895. On some fossils from the Nanaimo Group of the Vancouver Cretaceous. Transactions of the Royal Society of Canada, 2nd ser., 1(4);1 19-133, pis. 1-3. A new species of Miocene Zonaria (Mollusca: Gastropoda: Cypraeidae) from central Chile and its biogeographic significance Lindsey T. Groves’ and Sven N. Nielsen^ ' Natural History Museum of Los Angeles County, Malacology Section, 900 Exposition Boulevard, Los Angeles, California 90007 E-mail: lgroves@nhm.org ^ Universitat Hamburg,Geologisch-Palaontogisches Institut und Museum, Bundesstrasse 55, 20146 Hamburg, Germany E-mail: nielsen@geowiss.uni-hamburg.de Miocene cypraeids are rare in strata of western South America and were previously represented by only three species, Muracypraea henekeni (Sowerby, 1850) and Zonaria (Pseudozonaria) telembiensis (Olsson, 1964) both from the late Miocene Angostura Formation of Ecuador, and Muracypraea angustirima (Spieker, 1 922) from the middle Miocene, Zoroitos Formation of northwest Peru. A new species of Zonaria s.s. is described from the lower upper Miocene (Tortonian) Navidad Formation, north of Matanzas, Cardenal Caro Province, central Chile. This new species represents the southernmost record for a cypraeid species in the Western Hemisphere. The presence of this new cypraeid species and the associated warm-water gastropod genera Ficus, Distorsio, Xenophora, Echinophoria, and Olivancillaria in the Navidad Formation indicate that subtropical to tropical climatic conditions existed during the Miocene in what is now central Chile. Paleontology and geochronology of the middle and upper Pleistocene marine record in the downtown San Diego area, San Diego County, southern California 1 2 George L. Kennedy and Ian D. Browne 'Brian F. Smith and Associates, 14010 Poway Road, Suite A, Poway, CA 92064. E-mail: gkennedy@bfsa-ca.com ^Natural History Museum, P. O. Box 121390, San Diego, CA 92112 E-mail: ibrowne@sdnhm.org Introduction Paleontological monitoring and mitigation activities promulgated by environmental concerns for preserving archaeological and paleontological resources, as required by the California Environmental Quality Act (CEQA) and to be implemented by local governmental agencies, has resulted in a greatly enhanced understanding of local stratigraphic and paleontological relationships of subsurface estuarine sedimentary units in the downtown area of the City of San Diego, San Diego County, California. The lead agency responsible for implementing Western Society of Malacologists Annual Report, Vol. 36, p 13 environmental mitigation measures in downtown San Diego is the Centre City Development Corporation (CCDC). The CCDC has subdivided the Centre City area into eight districts or sub areas, of which six (Cortez Hill, Little Italy, Columbia, Marina, Gaslamp Quarter, and East Village) have yielded Pleistocene marine faunas in recent building excavations that are discussed herein. Due to limitations of this study, older museum collections from the Core and Horton Plaza areas are not discussed herein. The latest phase of building construction activity in the downtown area of San Diego began in the late 1990s and continues unabated in the early 2000s. Much of this redevelopment activity is associated with the recent construction of a new major league ballpark (Petco Park) for the San Diego Padres baseball team in the East Village area. Although paleontological monitoring activities continue throughout western San Diego County, in both the City of San Diego and in outlying cities, the focus of this discussion is limited to the results of monitoring activities in new building excavations in the downtown areas of San Diego [prior to mid-2003]. Geographically, the investigation encompassed the flat lying areas of the city southwest of Balboa Park and the Interstate 5 freeway to the margin of San Diego Bay and southeast of Laurel Street and Lindberg International Airport and northwest of the Coronado Bridge and freeway approaches. Background and History The first mention of Pleistocene fossils from along the waterfront of San Diego Bay, in an area that is now somewhat south of downtown San Diego, was that of Dali (1878a, b), who listed 24 species of bivalves and gastropods and described Anomia limatula n. sp. [=A. peruviana d’Orbigny, 1846] from sediments that can only be those at the foot of 26th Street at Indian Point. The Indian Point locality was also discussed by Ralph Arnold (1903: 59 ff, pi. 35, fig. a), who listed a fauna of 54 species, by Frank Stephens (1929), who listed 12 abundant species from SDSNH loc. 54, by Valentine (1961), who reported a fauna of 65 molluscan species, and by Thompson (1967). This locality is assigned to the Bay Point Formation, a name proposed by Hertlein and Grant (1939) based on exposures on the west side of Crown Point (“Bay Point”) in Mission Bay, as well as additional exposures around Mission Bay, San Diego Bay, and on North Island and Coronado (z.e., at Spanish Bight). In the 1950’s, 1960’s, and early 1970’s, numerous late Pleistocene faunas were described from the San Diego coastal areas by Warren Addicott, Emery Chace, William Emerson, Phil Kem (and students), Don Thompson, and James Valentine, although none of the newly described faunas was from the downtown part of San Diego. The only older Pleistocene fauna described from the greater San Diego area was that from the Lindavista Formation (Kennedy, 1973), far inland from the downtown area. The first modem geologic maps of the Del Mar, La Jolla, and Point Loma 7.5-minute (1:24,000 scale) quadrangles were published in 1975. In these, Kennedy (1975) assigned most of the low, flat lying coastal areas to the Bay Point Formation. Subsequently, Kem (1977) separated out and described two low marine terraces, the Nestor Terrace (of Ellis, in Ellis and Lee, 1919) and the Bird Rock Terrace, in the coastal areas previously mapped as the Bay Point Formation by Kennedy (1975). Paleontologists now generally assign the coastal terrace deposits to either the Nestor or Bird Rock Terrace, and assign the protected estuarine sedimentary exposures to the Bay Point Formation, although some of these assignments in the north county areas may be overextended. Western Society of Malacologists Annual Report, Vol. 36, p 14 Demere (1981) and Demere and Streiff (1982) were the first to recognize that marine faunas older than those of the Bay Point Formation existed in subsurface sediments in the downtown San Diego area, as well as in surface exposures in the northern Point Loma area (Loma Portal) and in southeast San Diego. They proposed the name “Broadway fauna” for their newly recognized assemblages, based in main part on collections recovered from a sewer line trench down Broadway near its intersection with Second Avenue (Demere, 1981, table 1; Elder, 1982, table 2). Among the species considered diagnostic of the new “Broadway fauna” were the bivalves Argopecten abietis abbotti, Pecten vogdesi, and the gastropod Turritella gonostoma. In addition to the downtown assemblages, Demere (1981) assigned the fauna from one of the supposed Nestor Terrace localities of Kern (1977, SDSU loc. 2530) from northern Point Loma to the “Broadway fauna.” Demere (1981) also pointed out that the purported Pliocene records of Hertlein and Grant (1972) for both Argopecten abietis abbotti and Pecten vogdesi should also be assigned to the “Broadway fauna.” A similar interpretation is made herein for the “Pliocene” records of the bivalve Megapitaria squalida. On the basis of amino acid racemization data on Chione, an age of 560,000 years was assigned to the “Broadway fauna,” and an age of 220,000 years was assigned to a younger downtown fauna named the “E Street fauna” (Demere, 1981) The only subsequent literature records of elements of the “Broadway fauna” were citations of Euvola vogdesi, Megapitaria sp., and Turritella gonostoma recovered from subbottom geotechnical borings in San Diego Bay prior to an earthquake retrofit of the Coronado Bridge (Kennedy, 1999a; Kennedy and Clarke, 2001). Fragments of large pectens were also observed, but not further identified. They may well be assignable to Argopecten abietis abbotti upon further examination. Geochronology and Correlation The Pleistocene marine terraces and correlative deposits in the San Diego area are well dated and have been utilized in a number of developmental studies of Quaternary dating techniques, such as amino acid racemization (aminostratigraphy) {e.g., Wehmiller et al., 1977), zoogeographic correlation (Kennedy et al., 1982), and uranium-series disequilibrium. On the basis of these studies, the Bird Rock Terrace dates to about 80,000 years BP, and is correlative with substage 5a of the marine oxygen isotope (8 O) record (Kern, 1977; Kennedy et al., 1982; Muhs et al., 1992, 1994). The older and higher Nestor Terrace dates to about 120,000 years BP, and is correlative with substage 5e of the oxygen isotope record (Ku and Kern, 1974; Kem, 1977; Kennedy et al., 1982; Muhs et al., 1992, 1994). The Bay Point Formation at its type locality and elsewhere generally represents depositional events, often in protected estuarine environments, that occurred contemporaneously with erosional cutting of, and deposition on, the Nestor Terrace as exposed on the outer coasts of Point Loma and La Jolla. The “E Street fauna” of downtown San Diego (Demere and Streiff, 1982) is also here assigned to the ~ 120,000 year BP, substage 5e Bay Point Formation. Based on the results of new excavations and resulting faunal collections (Table 2) from eight of 22 building excavation sites (Figure 1) in the greater downtown San Diego area (this study, see below), it is evident that two temporally distinct, stratigraphically separate, and taxonomically recognizable faunal assemblages are present in subsurface sediments below the upper Pleistocene Bay Point Formation. In the broad sense, these correlate with the “Broadway Western Society of Malacologists Annual Report, Vol. 36, p 15 fauna” of Demere (1981) and Demere and Streiff (1982). However, the type “Broadway fauna” (Demere, 1981, table 1) was based on a composite collection from two stratigraphic units that are here distinguished and informally referred to as the “upper Broadway” and “lower Broadway” faunas, or faunal horizons. The “upper Broadway” is characterized locally by the abundance of Turritella gonostoma Valenciennes, 1832, a depauperate gastropod fauna, and a reasonably diverse bivalve fauna. The “lower Broadway” fauna locally is characterized by the pectens Euvola vogdesi (Arnold, 1906) and the extinct Argopecten abietis abbotti (Hertlein and Grant, 1972), and by the lack of the distinctive Turritella gonostoma. Another common bivalve, found in both the “upper” and “lower Broadway” horizons, is the venerid Megapitaria squalida (Sowerby, 1835). Although other Surian and Panamic species may be common in Bay Point Formation sediments, it is unclear why these species are typically absent locally, except as reworked elements {cf. Table 1). Euvola, Megapitaria, and Turritella are all present farther north in the temporally equivalent substage 5e, -120,000 year BP, Palos Verdes Sand of the Upper Newport Bay area in Orange County (Kanakoff and Emerson, 1959; Grant et al., 1999). The separation of the composite “Broadway fauna” into two discrete, taxonomically distinguishable assemblages is based on careful collecting procedures, detailed geologic observations, and recognition of the uniqueness of the association, or lack thereof, of certain locally biostratigraphically characteristic species {e.g., Turritella gonostoma in the “upper Broadway” faunas, and lack of Turritella and dual presence of the scallops Euvola vogdesi and the extinct Argopecten abietis abbotti in the “lower Broadway” faunas, although all are also known as reworked elements in stratigraphically younger deposits {cf. Tables 1 and 2). Unequivocal evidence of biostratigraphic separation of the upper and lower faunal horizons is in the formational sediments themselves. Excavation for the PI Parking structure [now Padres’ Parkade] in the East Village area between Tenth and Eleventh Avenues and between Island Avenue and J Street exposed about 20 feet of vertical section. A well preserved “upper Broadway” fauna dominated by Turritella gonostoma was present at the 30 foot elevation level. This unit unconformably overlay a paleosol (buried soil horizon) developed upon a second marine unit carrying a “lower Broadway” fauna (at 23 feet elevation) with specimens, some paired, of both Euvola vogdesi and Argopecten abietis abbotti. The significance of the paleosol between the two marine units is that it is indicative of an appreciable period of subaerial exposure (and soil development) prior to a subsequent marine inundation associated with the “upper Broadway” fauna. A similar stratigraphic juxtaposition was noted during excavations accompanying the Horton Plaza redevelopment project in the early 1980s (SDSNH Iocs. 3171-A, 3171-B). Pleistocene marine terrace faunas and coeval estuarine faunas can be assigned ages based on our knowledge of paleoclimatic conditions that existed during previous interglacial sea level highstands of the last half million years, as interpreted from the marine oxygen isotope (8 O) record. The oxygen isotope record can be interpreted several ways, including as proxy curves for both sea level (or glacial-ice volume) and paleoclimate (temperature). Whereas the local late Pleistocene faunas have been directly dated by a variety of methods, we must use the marine oxygen isotope curve as a proxy both for the height of sea level and for the degree of paleoclimatic warming of the oceans for earlier, middle Pleistocene faunas. During substage 5a (-80,000 years BP), sea level was probably 5 to 7 meters below that of modem levels, and paleoclimatic conditions were somewhat cooler. Outer-coast marine terrace Western Society of Malacologists Annual Report, Vol. 36, p 16 faunas {e.g., those from the Bird Rock Terrace) typically contain a distinct cool-water element, and between 10% and 20% extralimital northern species in their faunas (Kennedy et aL, 1982, 1993; Kennedy, 1999b). Protected bay and estuarine faunas, however, typically lack cool-water species, perhaps due to greater summer insolation and seasonality during substage 5a time (c/ Kennedy, 1988; Berger and Loutre, 1991). Conversely, during substage 5e (-120,000 years BP), sea level was probably about 6 meters higher than modern levels, and paleoclimatic conditions were much warmer, particularly in protected bodies of water. Substage 5e estuarine faunas {e.g., those from the Bay Point Formation) typically have a strong component of warm- water, extralimital southern species, but only a minor warm-water element in unprotected outer- coast exposures {e.g., those on the Nestor Terrace). The limited number of warm-water interglacial periods prior to substage 5e, as reflected in the marine oxygen isotope record, restricts the range of possibilities for assigning ages to geologically recent sea level incursions into the San Diego embayment. Based on the tropical to subtropical nature of both the “upper” and “lower Broadway” faunas, the most plausible age assignments, correlative with the warmest periods of the last half million years, would be to oxygen isotope stage 9 (~ 330,000 ± years BP) for the “upper Broadway” fauna, and oxygen isotope stage 1 1 (~ 405,000 ± years BP) for the “lower Broadway” fauna. Assignments to isotope stages 9 and 13 or 1 1 and 13 are less likely, but not entirely undefensible. If we accept isotope stages 9 and 1 1 as correlative with the “upper” and “lower Broadway” faunas, respectively, then formation of the intervening paleosol would correlate with subaerial exposure during isotope stage 10 (~ 350,000 ± years BP). Although a depositional scenario for the upper and middle Pleistocene marine record in the San Diego embayment now seems well grounded, based on a variety of criteria, this level of understanding has not been extended beyond the downtown area. For example, it now appears likely that several of the Pleistocene estuarine faunas in northern San Diego County, in San Dieguito Valley (Stephens, 1929; Demere, 1980), San Elijo Lagoon (SDSNH loc. 3241), Batiquitos Lagoon (Pasek, 1979; SDSU loc. 3220), and in Oceanside (Demere and Riney, 2000), may have been contemporaneous with all or part of the composite “Broadway fauna” of downtown San Diego. Further investigations in these areas seem warranted. Project Summaries This summary of downtown San Diego construction projects is based on paleontological monitoring activities, as well as cursory geologic examinations, at more than 20 building excavation sites in the downtown area, and representing construction sites in the Cortez Hill, Little Italy, Columbia, Marina, Gaslamp Quarter, and East Village sub areas of the Centre City Redevelopment Area of downtown San Diego. San Diego Natural History Museum staff have also monitored additional building excavations, the results of which are not included in this summary. All fossils have been deposited in the Invertebrate Paleontology Section of the Natural History Museum of Los Angeles County (LACMIP) and the Paleontology Department of the San Diego Natural History Museum (SDSNH). Of the more than 20 jobsites monitored or visited [prior to mid 2003], several resulted in little to no paleontological recovery, and are not included in the following site by site summary. It should be noted also, that residential and commercial building names will change with future ownerships, but their locations as given Western Society of Malacologists Annual Report, Vol. 36, p 17 below should adequately identify the project sites under discussion here. The projects are discussed geographically from northwest (Little Italy neighborhood) to southeast (East Village area). The number in parentheses following the project name identifies its location on Figure 1. Front and Beech Apartments (1). Little Italy neighborhood [CCDC Cortez Fiill sub area]. Excavation for the Front and Beech Apartments project encompassed the entire city block bounded on the north and south by Cedar and Beech Streets, and on the west and east by Front Street and First Avenue. An “upper Broadway” fauna was collected from an utility vault excavation on the northwest comer of First Avenue and Beech Street at a depth of about 11 to 12 feet below the ground surface (elevation ~ 57 to 58 feet) (LACMIP loc. 17264). The fauna consisted of 42 species, represented by 27 or more species of bivalve mollusks, perhaps seven species of gastropods, clionid sponge and spionid worm borings, two barnacles, decapod cmstacean remains, a sand dollar, and sting ray and indeterminate mammal(?) remains. The fauna is assigned to the “upper Broadway” horizon on the basis of the abundance of Tiirritella gonostoma. Acqua Vista Apartments (2). Little Italy neighborhood. Excavation for the Acqua Vista Apartments project encompassed the entire city block bounded on the north and south by Beech and Ash Streets, and on the west and east by Columbia and State Streets. A limited late(?) Pleistocene fauna, possibly representing the Bay Point Formation, was recovered from the basal sandy pebble-gravel layer overlying the marine abrasion surface cut across a prominent middle Pleistocene paleosol unit near the southwest comer of the excavation (LACMIP loc. 17263). The limited fauna consisted of at least 16 species, represented by seven species of bivalves, five or more species of gastropods, clionid sponge borings, and one acorn barnacle. The fauna is tentatively assigned to the Bay Point Formation on the basis of a single specimen of the tropical gastropod Eupleura muriciformis, abundant elsewhere in the Bay Point Formation {e.g., Kennedy, 1997) but not previously identified in either the “upper” or “lower Broadway” faunas {cf. Table 2). Allegro Tower (3). Little Italy neighborhood. Excavation for the Allegro Tower project encompassed the western half of the city block between Ash and Beech Streets, and fronting on the east side of Kettner Boulevard. Several fossiliferous horizons (Table 1) were encountered in this excavation. The uppermost (LACMIP loc. 17276) was associated with a basal pebbly sandy gravel unit that appears to represent a basal transgressive lag containing shells and shell fragments reworked from underlying units. The gravel might represent either a period of strong marine erosion, or possibly to the marine transgression that occurred during marine oxygen isotope (6 O) substage 5a, although evidence for this conclusion is lacking. Unconformably below the gravel unit, the main fossiliferous unit consisted of lenses of broken up shells and shell hash (LACMIP Iocs. 17277, 17278) and a basal transgressive shell lag (LACMIP loc. 17279) that, to date, have produced more than 100 species. This is the most diverse late Pleistocene marine assemblage known from the downtown San Diego area and is assigned to the Bay Point Formation. The composite fauna is represented by 50 or more species of bivalve mollusks, 35 species of gastropods, one scaphopod, clionid sponge and polychaete worm borings, decapod cmstacean Western Society of Malacologists Annual Report, Vol. 36, p 18 remains, five or more species of bamcles, shark and sting ray teeth, an unidentified small bone, and trace fossil remains. Four additional species (three bivalves and one gastropod) are reworked from older, “Broadway” sediments. The basal shell lag at LACMIP loc. 17279 is correlative with a similar, but much smaller, fauna previously recovered from the west side of Kettner Boulevard in the San Diego National Bank building excavation (SDSNH loc. 3412). Reworked, water-worn specimens of Turritella gonostoma, and the scallops Euvola vogdesi and the extinct Argopecten abietis abbotti, representative of the “upper” and “lower Broadway” faunas, respectively, are also present in the Allegro Tower collections (Table 1). A single Argopecten impression was recovered from an underlying middle Pleistocene silt unit in the northeast comer of the excavation (LACMIP loc. 17354). Broadway 655 (4). Central downtown area [CCDC Columbia sub area]. Excavation for the Broadway 655 office tower project encompassed most of the city block located on the southeast comer of Broadway and Kettner Boulevard. The only marine fossils recovered from here were from auger-boring spoils derived from sixty-foot deep borings (LACMIP loc. 17398) for a crane-support platform that was used during constmction of the high-rise building. The fossils, from a seven to 10 foot stratigraphic interval (50 to 60 foot depth, and elevation of 35 to 45 feet below sea level), consisted of broken up shells that are assigned to the “lower Broadway” fauna on the basis of the scallops Euvola vogdesi and Argopecten abietis abbotti. The fauna consisted of perhaps 20 species, represented by 13 or more species of bivalve mollusks, two gastropods, clionid sponge borings, encmsting bryozoans, one acorn barnacle, a tooth from a bony fish, and a small bone. The composite “Broadway fauna” was originally described on the basis of collections made seven blocks to the east, near the intersection of Second Avenue and Broadway (Demere, 1981; Demere and Streiff, 1982; Elder, 1982). Pinnacle Museum Tower (5). Marina district. Excavation for the Pinnacle Museum Tower project encompassed the entire city block bounded on the north and south by Market Street and Island Avenue, and on the west and east by Union and Front Streets. Fossils recovered from this excavation represent both the upper and middle Pleistocene. The upper Pleistocene unit (LACMIP loc. 17285) may possibly represent the early stage 5, substage 5e, sea level highstand (correlative with the Nestor Terrace on Point Loma around La Jolla) on the basis of stratigraphic superposition and geomorphic position, although none of the few recovered species can be considered diagnostic of this sea level event. The most abundant fossils from the excavation are from the “upper Broadway” faunal horizon, based on the abundance of Turritella gonostoma. The composite faunas from LACMIP Iocs. 17286, 17287, 17288, and 17290 consisted of at least 25 species, represented by 1 8 species of bivalve mollusks, two gastropods, clionid sponge borings, encmsting bryozoans, one acorn barnacle, a sting ray tooth and a bony-fish otolith. Eight species, or approximately 32 percent of the “upper Broadway” fauna, have not previously been reported in the limited published literature on the fauna {cf. Demere, 1981). In addition, spoils from anchor borings in the southern half of the excavation (LACMIP loc. 17289) yielded fragmented specimens of two scallops, Euvola vogdesi and Argopecten abietis abbotti, that are considered characteristic of the “lower Broadway” fauna, and are here assigned to that faunal horizon. Western Society of Malacologists Annual Report, Vol. 36, p 19 Trellis Fifth Avenue (6). Gaslamp Quarter. The excavation for the Trellis Fifth Avenue apartments building encompassed the southern half of the city block bounded on the west and east by Fifth and Sixth Avenues, and fronting on the north side of K Street. Miscellaneous shells were recovered from remnant spoils from a 50 foot deep dewatering well near the northwest comer of Sixth Avenue and K Street, but from an unknown depth interval (LACMIP loc. 17399). These may represent the “lower Broadway” fauna, based on the possible presence of Eiivola vogdesi. In the main building excavation (LACMIP loc. 1 7400), however, an “upper Broadway” fauna, characterized by numerous Turritella gonostoma, was recovered from an elevation of 19 to 23 feet below sea level, and about 9 to 14 feet below the top of the well developed middle Pleistocene paleosol that forms a distinctive stratigraphic marker unit in the East Village area. The fauna from this excavation has not yet been processed. Parkloft Apartments (7). East Village (Ballpark) district. The Parkloft Apartments project encompassed the northern part of the city block bounded on the west and east by Eighth and Ninth Avenues, and fronting on the south side of Island Avenue. The collections yielded a rich “upper Broadway” fauna with abundant Turritella gonostoma. The composite fauna (SDSNH Iocs. 4556 through 4559; LACMIP unprocessed) consisted of 33 species, represented by 24 species of bivalve mollusks, five species of gastropods, clionid sponge borings, a turtle barnacle, sting ray teeth and caudal spines, and an indeterminate mammal(?) bone. Nearly 40 percent of the fauna had not previously been recorded from the limited published literature on the fauna {cf. Demere, 1981, table 1). The presence of Euvola vogdesi is here regarded as a result of reworking following scouring by the marine transgression that cut across the older middle Pleistocene sediments containing a “lower Broadway” fauna, as recovered in the building excavations for the PI Parking stmcture, the Entrada Apartments and other building sites to the north and east. Geologically, the most interesting aspect of the Parkloft excavation was the discovery of a east-southeastwardly trending paleoshoreline running across the site, extending from the northwest corner of the excavation and subsequently identified in the Diamond Terrace excavation to the southeast. The shoreline angle was at an elevation of about 15 feet, and cut into the prominent paleosol developed on sediments containing the “upper Broadway” fauna. Rounded clasts of the paleosol material were present on the abrasion platform near the old shoreline. Marine sediments associated with the sea level event responsible for cutting of the shoreline were barren of fossils, although a limited molluscan fauna identified in a geotechnical trench to the south may be related to this shoreline. The shoreline probably represents the extent of the marine incursion that occurred during marine oxygen isotope substage 5e, and is thus correlative with the -120,000 year BP Bay Point Formation, and with the Nestor Terrace on the outer coast. Diamond Terrace (8). East Village (Ballpark) district. The Diamond Terrace apartments project site encompassed the northeast comer of Ninth Avenue and J Street, across Ninth Avenue directly southeast of the Parkloft project site. Only a limited “upper Broadway” fauna was recovered from the west side Western Society of Malacologists Annual Report, Vol. 36, p 20 of the excavation along Ninth Avenue (LACMIP loc. 17384). The fauna consisted of 18 or more species, represented by 14 or 15 species of bivalve mollusks, two gastropods, and clionid sponge and spionid worm borings. The paleoshoreline with a shoreline angle elevation of about 15 feet, first identified in the Parkloft excavaton, is also present in the Diamond Terrace excavation. The associated marine sediments, however, were barren of fossils. PI Parking structure (9). East Village (Ballpark) district. The excavation for the PI Parking structure [now Padres’ Parkade] encompassed most of the city block bounded on the west and east by Tenth and Eleventh Avenues, and on the north and south by Island Avenue and J Street. The project was not originally slated for paleontological monitoring by the CCDC, but nevertheless has yielded the most important paleontological data of any of the excavations in the East Village area [prior to mid 2003]. This excavation yielded both an “upper Broadway” fauna (LACMIP loc. 17392) characterized by the abundance of Turritella gonostoma, as well as “lower Broadway” faunas (LACMIP Iocs. 17393 through 17395) characterized by the scallops Euvola vogdesi and the extinct Argopecten abietis abbotti. The two faunas are separated by a paleosol developed upon the lower marine silt unit with the “lower Broadway” faunas. The significance of the intervening paleosol is that it indicates an appreciable period of subaerial exposure (and soil development) before the marine inundation and sedimentation associated with the “upper Broadway” fauna. Materials from these localities have yet to be processed. A similar stratigraphic relationship exists between the “upper” and “lower Broadway” faunas recovered from earlier excavations for the downtown Horton Plaza redevelopment project in the early 1980s (SDSNH Iocs. 3 171 -A, 3171-B), as well as in several more recent excavations in the Gaslamp Quarter and East Village areas [Kennedy and Stewart, in preparation]. Island Village (10). East Village district. The Island Village Apartments excavation encompassed most of the city block bounded on the west and east by Twelfth Avenue [now Park Boulevard] and Thirteenth Street, and on the north and south by Market Street and Island Avenue. The northern part of the excavation was not very deep, and yielded poorly preserved, but occasionally paired, specimens of Chione in a red sandstone unit overlying a basal Anomia-Ostrea lag. Although regarded as middle Pleistocene in age on the basis of its preservation, the limited fauna lacks any of the typical species that characterize either the “upper” or “lower Broadway” faunas. Fault investigation trench on Market Street (11). East Village district. A shallow fault investigation trench around the southwest comer of Market and Fourteenth Streets has yielded spoils that were derived from one of the middle Pleistocene Anomia-Ostrea shell lags, and from underlying sandstones with a “lower Broadway” fauna characterized by the scallop Euvola vogdesi and the large cockle Laevicardium elatum. On the east side of Fourteenth Street, between Market Street and Island Avenue, the Natural History Museum recovered a diverse “lower Broadway” fauna from their Market Square Manor project (SDSNH loc. 4729), including a number of species not represented in Table 2. Western Society of Malacologists Annual Report, Vol. 36, p 21 Entrada Apartments ( 1 2). East Village district. Excavation for the Entrada Apartments project encompassed the northern part of the city block bounded on the west and east by Thirteenth and Fourteenth Streets, and fronting on the south side of Island Avenue. Fossils recovered from the Entrada excavation include a prominent Anomia-Ostrea shell lag (LACMIP loc. 17274) and an underlying sandstone with abundant scallops, Euvola vogdesi and Argopecten abietis abbotti, characteristic of the “lower Broadway” faunal horizon. The lower unit (LACMIP loc. 17269) yielded a fauna of 26 species, consisting of 18 species of bivalve mollusks, five or more gastropods, clionid sponge and spionid worm borings, and sting ray remains. Of the 24 identifiable taxa, nine species, or 37.5 percent of the fauna, had not previously been recorded in the limited published literature on the fauna {cf. Demere, 1981, table 1). A single Argopecten impression was recovered from the underlying silt unit (LACMIP loc. 17275). Summary Pleistocene marine invertebrate faunas from the downtown areas of the City of San Diego, California, document at three marine incursions into the San Diego embayment during the last half million years. The presence of any marine faunas correlative with the latest sea level highstand of marine oxygen isotope (6180) substage 5a and with the -80,000 year BP Bird Rock Terrace is equivocal. Faunas correlative with the +6 meter sea level highstand of oxygen isotope substage 5e, responsible for cutting of the Nestor Terrace about 120,000 years BP, are assigned to the Bay Point Formation. A paleoshoreline attributable to this sea-level event has been recognized in the East Village area at an elevation of about 15 feet, but the associated marine sediments were barren of fossils. The most diverse Bay Point Formation fauna from the downtown area, in the Allegro Tower excavation on Kettner Boulevard, yielded more than 100 species of marine invertebrates (Table 1). Estuarine faunas from the Bay Point Formation are characterized by the presence of extralimital southern species that today range no farther north than the outer coast of central peninsular Baja California. Middle Pleistocene marine faunas were first recognized in the downtown area by Demere (1981) and Demere and Streiff (1982), who applied the name “Broadway fauna” to them. The “Broadway fauna,” however, was based on a composite collection from two stratigraphic units that are here informally referred to as the “upper” and “lower Broadway” faunas (Table 2). The upper fauna, characterized by the abundance of the gastropod Turritella gonostoma, dates to the sea-level highstand of marine oxygen isotope stage 9 and is assigned an age of about 330,000 years BP. The “lower Broadway” fauna, characterized by two scallops, Euvola vogdesi and the extinct Argopecten abietis abbotti, dates to the sea-level highstand of marine oxygen isotope stage 1 1 and is assigned an age of about 400,000 years BP Only 18 species were originally identified in the composite “Broadway fauna” from the downtown area. We recognize at least 28 species of marine invertebrates, mainly bivalve mollusks, and two vertebrates from the “lower Broadway” fauna, and at least 48 species of marine invertebrates, also mainly bivalve mollusks, and two species of vertebrates from the “upper Broadway” fauna. It should be noted, however, that many of the downtown building excavations are continuing to encounter faunas from both the “upper” and “lower Broadway” faunal horizons, and the known diversity from each continues to increase with each new project. Western Society of Malacologists Annual Report, Vol. 36, p 22 In that respect, the data summarized herein [to mid 2003] must be considered only as “state of the art,” but not the final word on the downtown Pleistocene faunas of the San Diego area. Given the continuing development of this part of the City, our knowledge of the subsurface estuarine sediments and their faunas should continue to increase in the coming years. Literature cited Arnold, Ralph. 1903. The paleontology and stratigraphy of the marine Pliocene and Pleistocene of San Pedro, California. Memoirs of the California Academy of Sciences, vol. 3; 1-420, pis. 1-37. Berger, A. and Loutre, M. F. 1991. Insolation values for the climate of the last 10 million years. Quaternary Science Reviews, 10; 297-317. Dali, W. H. 1878a. Fossil mollusks from later Tertiaries of California. Proceedings of the United States National Museum, 1: 10-16. Dali, W. H. 1878b. Distribution of California Tertiary fossils. Proceedings of the United States National Museum, 1 : 26-30. Demere, T. A. 1980. A late Pleistocene molluscan fauna from San Dieguito Valley, San Diego County, California. Transactions of the San Diego Society of Natural History, 19(15): 217- 226, figs. 1-4, tables 1-2. Demere, T. A. 1981. A newly recognized late [^middle] Pleistocene marine fauna from the City of San Diego, San Diego County, California. In Abbott, P. L., and O’Durm, S. A., eds.. Geologic investigations of the San Diego coastal plain. Field trip guidebook prepared for San Diego Association of Geologists, Field Trip, April, 1981, pp. 1-10, fig. 1, pi. 1, table 1. Demere, T. A. and Riney, B. O. 2000. Paleoenvironments, paleoecology, and molluscan paleontology of a late Pleistocene bay, Oceanside, San Diego County, California [abstract]. Western Society of Malacologists, Annual Report, 32: 13-14. Demere, T. A. and Streiff, D. W. 1982. Recognition of middle and upper Pleistocene marine deposits in downtown San Diego, California [abstract]. American Association of Petroleum Geologists Bulletin, 66(10): 1687. Elder, D. L. 1982. A critical examination and evaluation of the structure and stratigraphy in the downtown San Diego area, California. Unpublished M.S. thesis. Department of Geological Sciences, San Diego State University. Pp. i-x + 1-151, figs. 1-10, pis. 1-7, tables. Ellis, A. J. and Lee, C. H. 1919. Geology and ground waters of the western part of San Diego County, California. United States Geological Survey, Water-Supply Paper 446: 1-321, figs. 1-18, pis. 1-47, tables 1-64. Western Society of Malacologists Annual Report, Vol. 36, p 23 Grant, L. B. Mueller, K. J. Gath, E. M. Cheng, H. Edwards, R. L. Munro, R. and Kennedy, G. L. 1999. Late Quaternary uplift and earthquake potential of the San Joaquin Elills, southern Los Angeles basin, California. Geology, 27(1 1): 1031-1034, figs. 1-4, table 1. Hertlein, L. G. and Grant, U. S. IV. 1939. Geology and oil possibilities of southwestern San Diego County. In Report XXXV, of the [California] State Mineralogist. California Journal of Mines and Geology, 35(1): 57-78, figs. 1-8. Hertlein, L. G. and Grant, U. S. IV. 1972. The geology and paleontology of the marine Pliocene of San Diego, California (Paleontology: Pelecypoda). Memoirs of the San Diego Society of Natural History, 2(2B): 135-409, figs. 7-13, pis. 27-57. Kanakoff, G. P. and Emerson, W. K. 1959. Late Pleistocene invertebrates of the Newport Bay area, California. Los Angeles County Museum, Contributions in Science, 31: 1-47, figs. 1-5, tables 1-3. Kennedy, G. L. 1973. A marine invertebrate faunule from the Lindavista Formation, San Diego, California. Transactions of the San Diego Society of Natural History, 14(19): 1 19-127, figs. 1-3. Kennedy, G. L. 1988. Zoogeographic discordancy in late Pleistocene northeastern Pacific marine invertebrate distributions explained by astronomical theory of climate change [abstract]. Geological Society of America, Abstracts with Programs, 20(7): A207-A208. Kennedy, G. L. 1997. Late Pleistocene invertebrate record of San Diego Bay, southern California [abstract]. Western Society of Malacologists, Annual Report, 29: 5-6. Kennedy, G. L. 1999a. Paleontological analysis of Coronado Bridge borings, San Diego Bay, California. In Kennedy, M. P., and Clarke, S. H., Jr., Age of faulting in San Diego Bay in the vicinity of the Coronado Bridge — An addendum to — Analysis of late Quaternary faulting in San Diego Bay and hazard to the Coronado Bridge. California Division of Mines and Geology, DMG Open File Report 97-1 OB: Appendix 1, pp. 1-1-1-69, tables 1-3. Kennedy, G. L. 1999b [“2000”]. Zoogeographic correlation of marine invertebrate faunas. In Noller, J. S., Sowers, J. M., and Lettis, W. R., eds.. Quaternary geochronology - Methods and applications. American Geophysical Union, AGU Reference Shelf 4: 413-424, figs. 1-3. Kennedy, G. L. Lajoie, K. R. and Wehmiller, J. F. 1982. Aminostratigraphy and faunal correlations of late Quaternary marine terraces. Pacific Coast, USA. Nature, 299(5883): 545- 547, figs. 1-2. Kennedy, G. L. Wehmiller, J. F. and Rockwell, T. K. 1993 [“1992”]. Paleoecology and paleozoogeography of late Pleistocene marine-terrace faunas of southwestern Santa Barbara Western Society of Malacologists Annual Report, Vol. 36, p 24 County, California. In Fletcher, C. H., Ill, and Wehmiller, J. F., eds.. Quaternary coasts of the United States: Marine and lacustrine systems. SEPM (Society for Sedimentary Geology), Special Publication 48: 343-361, figs. 1-2, tables 1-3. Kennedy, M. P. 1975. Geology of the western San Diego metropolitan area, California. Del Mar, La Jolla, and Point Loma quadrangles. Section A, o/Geology of the San Diego metropolitan area, California. California Division of Mines and Geology, Bulletin 200: 7-39, figs. 1-9, photos 1-8, pis. 1A-3A (map sheets, scale 1:24,000). Kennedy, M. P. and Clarke, S. H., Jr. 2001. Late Quaternary faulting in San Diego Bay and hazard to the Coronado Bridge. California Geology, 55(4): 4-17, figs. 1-6. Kern, J. P. 1977. Origin and history of upper Pleistocene marine terraces, San Diego, California. Geological Society of America Bulletin, 88(1 1): 1553-1566, figs. 1-9, tables 1-2. Ku, T.-L. and Kern, J. P. 1974. Uranium-series age of the upper Pleistocene Nestor terrace, San Diego, California. Geological Society of America Bulletin, 85(1 1): 1713-1716, fig. 1, tables 1-2. Muhs, D. R. Kennedy, G. L. and Rockwell, T. K. 1994. Uranium-series ages of marine terrace corals from the Pacific coast of North America and implications for last-interglacial sea level history. Quaternary Research, 42(1): 72-87, figs. 1-16. Muhs, D. R. Rockwell, T. K. and Kennedy, G. L. 1992. Late Quaternary uplift rates of marine terraces on the Pacific Coast of North America, southern Oregon to Baja California Sur. Quaternary International, 15/16: 121-133, figs. 1-5, table 1. Pasek, J. E. 1979. The paleoenvironment of a late Pleistocene estuary in coastal southern California. Unpublished Geology 498B student report. Department of Geological Sciences, San Diego State University. Pp. i + 1-26, fig. 1, pis. 1-5, tables 1-3. Stephens, Frank. 1929. Notes on the marine Pleistocene deposits of San Diego County, California. Transactions of the San Diego Society of Natural History, 5(16): 245-255, fig. 1. Thompson, D. E. 1967. Paleoecology of the San Diego marine Pleistocene. Unpublished M.S. thesis. Department of Biology, San Diego State College. Pp. i-vi + 1-100, figs. 1-3, tables 1-10. Valentine, J. W. 1961. Paleoecologic molluscan geography of the Californian Pleistocene. University of California Publications in Geological Sciences, 34(7): i-iv + 309-442, figs. 1-16, tables 1-33. Wehmiller, J. F. Lajoie, K. P. Kvenvolden, K. A. Peterson, Etta, Belknap, D. F. Kennedy, G. L. Addicott, W. O. Vedder, J. G. and Wright, R. W. 1977. Correlation and chronology of Western Society of Malacologists Annual Report, Vol. 36, p 25 Pacific Coast marine terrace deposits of continental United States by fossil amino acid stereochemistry - Technique evaluation, relative ages, kinetic model ages, and geologic implications. U. S. Geological Survey, Open-File Report 77-680: i-iv + 1-196, figs. 1-18, tables 1-13. Western Society of Malacologists Annual Report, Vol. 36, p 26 TABLE 1 Preliminary list of late Pleistocene marine fossils from the Allegro Tower excavation site on Kettner Boulevard between Ash and Beech Streets, Little Italy neighborhood, downtown San Diego, San Diego County, California (LACMIP Iocs. 17276, 17277, 17278 and 17279). Abbreviations: x, present; (R), reworked from older, middle Pleistocene units (“Broadway fauna”); c/, compare with; f(f), fragment(s) only; indet., indeterminate; j(j), juvenile(s); s.L, sensu lato; sp., species (unidentified); ?, identification questionable; *, recorded from a stratigraphically equivalent horizon nearby. Species Locality Mollusca: Bivalvia 17276 17277 17278 17279 Amiantis callosa (Conrad, 1837) X ?lf _ _ Anomia peruviana d’Orbigny, 1846 X X X X Argopecten abietis abbotti (Hertlein & Grant, 1972) (R2f) (R?) (R) - Argopecten sp., indet. ff x,ff x,ff X Barnea subtnmcata (Sowerby, 1834) - ff - - Cardiidae, indet. ff 2f 2f - Chama arcana Bernard, 1976 - X X - Chione californiensis (Broderip, 1835) ? X X - Chione sp., aff. C. californiensis (Broderip, 1835) (*R) (R) (R) - Chione fluctifraga {Sovjerhy , 1853) - - X ?lf Chione gnidia (Broderip & Sowerby, 1 829) (R?2f) X X - Chione picta'^'xWed, 1944 - 1 - - Chione undatella {SiOv^erhy, 1835) X X X jj Chione sp. /spp. ff,(R) jj,(R) jj,(R) jj Corbula sp. - 1 - - Crassinella nuculiformis Berry, 1 940 - X X X Crassinella sp. - - 1 - Cryptomya californica {Corvrad, 1837) - X X - Cumingia califomica Conrad, 1837 - - 2f - Diplodonta sericata (Reeve, 1 850) X X X X Donax californicus {Comad, 1837) - X X - Donax gouldii Dali, 1 92 1 If X X X Dosinia ponderosa (Gray, 1838) If ff X - Ensis sp., ? E. myrae Berry, 1953 - - If - Euvola vogdesi (Arnold, 1 906) (R,ff) (R,ff) (R,ff) - Florimetis obesa (Deshayes, 1855) - - 3f - Glycymeris sp. - * X - Western Society of Malacologists Annual Report, Vol. 36, p 27 17276 Mill 17278 17279 Here excavata (Carpenter, 1 857) - X - - Juliacorbula luteola (Carpenter, 1 864) - X X X Laevicardiim elatum (Sowerby, 1833) * 2f 2f - Laevicardiiim substriatiim (Conrad, 1837) - X - - Leptopecten latiauratus (Conrad, 1837) 3f X X X- Liicinisca nuttalli (Conrad, 1 837) X X X X Lyonsia sp. ?lf - - Macoma nasuta {Comad, 1837) If X X cf. Mactridae, indet. - X X - Megapitaria squalida (Sowerby, 1835) (Rff) (?1R) (R) - Nucula exigua Sowerby, 1833 - X X X Nuttallia nuttallii (Conrad, 1 837) - * - - Nutricola tantilla (Gould, 1 853) - X X X Ostrea conchaphila Carpenter, 1857 X X X X Ostrea sp. (?R) - Ij - Parvilucina approximata (Dali, 1901) - X X - Pectinidae, indet. fragments ff ff ff X Petricola californiensis Pilsbry & Lowe, 1932 - If ?lf - Petricola carditoides (Conrad, 1837) - - 2f - Petricolaria cognata (Adams, 1852) Pitar helenae Olsson, 1 961 , or 3f X X X P. newcombianus {Gahh, 1865) - X ?1 - Protothaca laciniata (Carpenter, 1 864) - - If - Protothaca staminea (Conrad, 1837) ?lf - X - Protothaca tenerrima (Carpenter, 1857) - ?lf 2f - Psammotreta viridotincta (Carpenter, 1856) - 2f ?lf - Raeta undidata (Gould, 1851) - 2f 4f - ScLxidomus sp. ?lf - If - Semele decisa {Comad, 1837) If 2f 3f - Semele pulchra {Sowerby, 1832) - X X X Tagelus californianus (Conrad, 1837) - ff ff - Tagelus sp., indet. (fragments) - ff ff - Tellina meropsis Dali, 1 900 - X X - Trachycardium procerum (Sowerby, 1833) ?lf X X - Veneridae, indet. - - - 2f Zirfaea pilsbryi Lowe, 1 93 1 - - 3f - Bivalvia, indet. fragments (several species) ff ff ff - Western Society of Malacologists Annual Report, Vol. 36, p 28 Mollusca: Gastropoda Acanthinucella spirata (Blainville, 1 832) - - If Acteocina sp./spp. - ff 1 Astraea undosa (Wood, 1828) - - If Bulla gouldiana Pilsbry, 1 893 17276 2f 17277 17278 Calliostoma gemmulatum Carpenter, 1 864 - 2f 2f Calliostoma sp. - If - Cerithidea californica (Haldeman, 1 840) - X X Conus californicus Reeve, 1 844 - If 2f Crepidula onyx Sowerby, 1 824 ?2f X X Crepidula perforans (Valenciennes, 1846) - X X Crepidula sp./spp., indet X x,jj X Crucibulum spinosum (Sowerby, 1824) If X X Diodora arnoldi McLean, 1 966 If X X Lirularia sp. - X X Lottia or Collisella sp. - - 1 Lucapinella callomarginata (Dali, 1871) - 1 - Macron aethiops (Reeve, 1847) (s.l.) - - 2f Megathura crenulata (Sowerby, 1 825) - - If Mitrella carinata (Hinds, 1 844) - X - Muricidae, unidentified fragments - X ff Nassarius mendicus (Gould, 1 849) - 1 If Nassarhds mendicus indisputabilis (Oldroyd, 1927^ - 2 X Nassarius tegula (Reeve, 1853) - X X Nassarius sp./spp. (fragments) - ff If Naticidae, indet. (borings in shell) X X X Neverita reclusiana (Deshayes, 1839) X X X Ocenebra foveolata (Hinds, 1 844) - - ff Odostomia sp. - 1 - Olivella baetica Carpenter, 1 864 - X - Olivella biplicata (Sowerby, 1825) - X - Olivella sp. - If - Pteropurpura festiva (Hinds, 1 844) - - X Roperia poulsoni (Carpenter, 1 864) - - If Tegula aureotincta (Forbes, 1 852) - - 2f Tegula eiseni Jordan, 1936 - ?lf ?2f Tegula gallina (Forbes, 1 852) - * - Tegula sp. - f - Terebra sp. X - - Tricolia compta {Gon\A, 1855) - X X Turritella gonostoma Valenciennes, 1832 (R) - (R) Microgastropods, unidentified - X X Gastropoda, indet. f X ff 17279 X If X Western Society of Malacologists Annual Report, Vol. 36, p 29 Moliusca: Scaphopoda Dentalium neohexagonum Sharp & Pilsbry, 1897 XXX Porifera: Demospongae Clionidae, indet. (borings in shell) Bryozoa: Gymnolaemata Discoporella umbellata (Defrance, 1823) Encrusting bryozoans, unidentified Annelida: Polychaeta Spionidae, indet. Arthropoda: Crustacea (Cirripedia) Balanus pacificus Pilsbry, 1916 '^'Balanus" (s.l.) sp. or spp. (unidentified) Chelonibia testudinaria (Linnaeus, 1767) Cryptolepas murata ZxiWo, 1961 Tetraclita rubescem Darwin, 1854 Arthropoda: Crustacea (Malacostraca) Decapoda, indet. (crab parts, etc.) Chordata: Chondrichthyes Myliobatis californica G'\W, \?>65 (stingray) (teeth) Unidentified small shark (tooth) Unidentified shark or ray Chordata: class uncertain Small bone, class undetermined Ichnofossils: incertae sedis Minute herring-bone pattern of tiny holes in shell 17276 Mill 17278 17279 X X X X X X X ? X X X X X If - If * - X XXX If 3f ff 1 ?1 * 1 1 X X Western Society of Malacologists Annual Report, Vol. 36, p 30 TABLE 2 Preliminary list of middle Pleistocene species from the “lower” and “upper Broadway” faunal horizons in the downtown San Diego area, based on collections made from building excavations in the Cortez Hill, Little Italy, Columbia, Marina, Gaslamp Quarter, and East Village parts of the Centre City Redevelopment Area of downtown San Diego, San Diego County, California (LACMIP and SDSNH collections). Abbreviations: (R), reworked from older unit; X, present; ff, fragment(s) only. Species Mollusca: Bivalvia Anadara sp. nov.? Anomia peruviana d’Orbigny, 1846 Argopecten abietis abbotti (Hertlein & Grant, 1972) Argopecten sp., aff. A. ventricosus (Sowerby, 1842) Caryocorbula porcella (Dali, 1916) Chione californiensis (Broderip, 1835) Chione sp. aff. C. californiensis (Broderip, 1835) Chione fluctifraga , 1853) Chione gnidia (Broderip & Sowerby, 1 829) Chione undatella (Sowerby, 1835) Crassinella pacifica (Adams, 1 852) Cryptomya californica (Conrad, 1837) Cumingia californica Conrad, 1837 Diplodonta sericata (Reeve, 1 850) Diplodonta subquadrata (Carpenter, 1856) Euvola vogdesi (Arnold, 1 906) Juliacorbula luteola (Carpenter, 1 864) Laevicardium datum (Sowerby, 1833) Laevicardium substriatum (Conrad, 1837) Lucinisca nuttalli (Comad, 1837) Macoma indentata Carpenter, 1 864 Macoma nasuta (Comad, 1837) Mactrotoma californica (Comad, 1 837) Megapitaria squalida (Sowerby, 1835) Mytilidae, indet. (fragment) Nucula exigua Sowerby, 1833 Ostrea angelica Rochebrune, 1 895 Ostrea conchaphila CarpQniQT, 1857 Ostrea sp. Parvilucina sp. lower upper X X X X (R) X X ? X X X X X X X X X X X X X X X X (R) X X X X X X X X X X X X X X X X X X X X X Western Society of Malacologists Annual Report, Vol. 36, p 31 Pinnidae, indet. (fragments, P/wwa sp. or zi/r/wa sp.) ff Pitar newcombianus (Gabb, 1 865) or P. helenae Olsson, 1961 x x lower upper Psammotreta viridotincta {Carpenter, \S56) - x Tagelus californiamis (Comad, \S37) sp. x Tagelus (Mesopleura) sp., indet. - ff Tellina meropsis DaW, \900 x x Tellina sirmdans Adams, 1 852 - x Trachycardium procerum (Sov^trhy, \^?)?)) - x Mollusca: Gastropoda Bulla gouldiana Pilsbry, 1 895 - x Cerithidea californica (Haldoman, IS40) - x Crepidula sp., cf. C. onyx Sowerby, 1 824 - x Crucibulum spinosum (Sowerby, 1 824) - ? Epitonium (Nitidiscala) sp. - x Lucapinella callomarginata (DaW, \^1\) x Melampus olivaceous Carpenter, \S57 - x Nassarius tegula (Reeve, \S53) ? x Neverita reclusiana (Deshayes, \S39) x Turritella gonostoma Yalenciennes, \S32 - x Porifera: Demospongea Clionidae, indet. (borings in shell) x x Bryozoa: Gymnolaemata Encrusting bryozoans, unidentified x x Arthropoda: Crustacea (Cirripedia) ‘‘'Balanus" (sd.) spp. x x Chelonibia testudinaria (Lirmaeus, \7 67) - x Arthropoda: Crustacea (Malacostraca) Decapoda, indet. pieces - x Annelida: Polychaeta Spionidae, indet. (borings in shell) x x Western Society of Malacologists Annual Report, Vol. 36, p 32 Echinodermata: Echinoidea ? Dendraster sp. (fragments) Chordata: Chondrichthyes Myliohatis californica GiW, 1865 (sting ray: s, caudal spines; t, teeth) Chordata: Osteichthyes Teleostei, unidentified (bony fish: o, otolith; t, tooth?) ff lower upper s, t s, t t? o Western Society of Malacologists Annual Report, Vol. 36, p 33 lino w 117“09- i2’ »3' 'J 32' 12 Figure 1. Index map of downtown San Diego, San Diego County, California, showing locations of numbered building project sites discussed in text. Western Society of Malacologists Annual Report, Vol. 36, p 34 Paleontology of new middle Eocene faunas and floras from northern San Diego County, southern California George L. Kennedy, Jeffrey A. Myers, Stephen L. Walsh, and Ian D. Browne Brian F. Smith and Associates, 12528 Kirkham Ct., Suite 3, Poway, CA 92064 E-mail:gkennedy@brianfsmithandassociates.com Paleontological mitigation and monitoring activities at three mass grading projects in northern San Diego County, California, have yielded new collections and data on middle Eocene invertebrate (mainly molluscan), vertebrate faunas, and associated paratropical floras. Based on more than 300 collecting localities dispersed across three projects, the 4-S Ranch housing development west of Rancho Bernardo, the Westview High School site in Rancho Penasquitos, and the Cathedral High School site in Carmel Valley, we are able to reconstruct the environmental and paleoclimatic conditions that existed in this region approximately 45 million years ago. Volutoderminae (Gastropoda, Volutidae) from the Late Cretaceous of the Pacific slope of North America 1 2 LouElla R. Saul and Richard L. Squires ' Invertebrate Paleontology Section, Natural History Museum of Los Angeles County 900 Exposition Blvd., Los Angeles, CA 90007 E-mail: lousaul@earthlink.net ^ Department of Geological Sciences, California State University, Northridge, CA 91330 E-mail: richard.squires@csun.edu Large volutid gastropods of Late Cretaceous (Coniacian through Maastrichtian) age from southern British Columbia, Canada, to Baja California, Mexico, have commonly been identified as Volutoderma averillii (Gabb, 1864). Review of available specimens results in assignment to three genera.- Volutoderma Gabb, 1877, with eleven (possibly twelve) species, eight (or nine) of them new; Longoconcha Stephenson, 1941, with one new species; and Retipirula Dali, 1907, with one new species. The species of Volutoderma appear to form three lineages. 1) The earliest in occurrence and longest in time range is the lineage which includes the type species of Volutoderma, Fusus averillii Gabb, 1864. The V. averilli lineage comprises Volutoderma n. sp. q (Coniacian- Santonian age), V. averillii (early Campanian-early middle Campanian age), Volutoderma n. sp. b (middle Campanian to early late Campanian age), Volutoderma n. sp. j (late Campanian age), and Volutoderma n. sp. p (latest Campanian-early Maastrichtian age). If Volutoderma? n. sp. of late Maastrichtian age belongs to this lineage, the V. averillii lineage ranges in age from Coniacian to late Maastrichtian. 2) The second lineage ranges in age through middle and late Campanian and contains three new species of Volutoderma, Volutoderma n. sp. a, Volutoderma n. sp. e, and Volutoderma n. sp. y each of which had a duration of over 2 Ma. 3) The third lineage ranges in age from early to late Campanian and comprises V. santana Packard, 1922, V. Western Society of Malacologists Annual Report, Vol. 36, p 35 magna Packard, 1922, and Volutoderma n. sp. aa. The genus Volutoderma has been widely used for Cretaceous volutes, but the genus appears to be endemic to the Pacific Slope of North America. The similar Gulf Coast genus Volutomorpha Gabb, 1877, is fully glazed by a callus coat. Longoconcha n. sp. e, of latest Campanian to early Maastrichtian age, is the first species of Longoconcha to be recognized from Pacific Slope deposits. This genus has otherwise been reported from the Late Cretaceous of the Gulf Coast and Europe. Retipirula n. sp. c, of late Maastrichtian age, is the first species of this otherwise early late Paleocene genus to be reported from the Cretaceous. Only the Volutoderma averillii lineage has been found north of San Francisco. Because species of the three lineages and Longoconcha n. sp. e co-occur at southern California localities, species diversity of volutodermines in southern localities is two or three times greater than at northern localities. The presence of the Tethyan bivalve rudistid Coralliochama in the same formations as three-fourths of these southern Volutoderminae occurrences suggests that the diversity is linked to warm temperate to subtropical conditions. Paleontologic record of the pseudomelaniid gastropod Trajanella from the marine Cretaceous of the Pacific slope of North America I 2 Richard L. Squires and LouElla R. Saul ' Department of Geological Sciences, California State University, Northridge, CA 91330 E-mail: richard.squires@csun.edu ^ Invertebrate Paleontolog>' Section, Natural History Museum of Los Angeles County 900 Exposition Boulevard, Los Angeles, CA 90007 E-mail: lousaul@earthlink.net Trajanella is a tropical to marginally tropical, nearshore-marine pseudomelaniid gastropod primarily associated with the Old World Cretaceous Tethyan realm. The genus originated in western Europe and the Black Sea area during the latest Jurassic (Tithonian). It arrived onto the Pacific Slope of North America (northern California), possibly in the Aptian, but certainly by the late early Albian and, most likely, by way of Japan and the north Pacific gyre. Worldwide, the genus had its peak diversity during the Albian and Cenomanian. The only other Western Hemisphere records of Trajanella are a species from the Campanian of Jamaica and a possible species from the Coniacian of Texas. Six species are recognized by us. Four are previously named species but were misallocated to genus Acteonina. Only Trajanella acuminata Anderson, 1958, was originally correctly identified. It is from upper lower Albian strata in Shasta County, California. The other species are: Trajanella calafia (Stewart, 1927) from possible Aptian or Albian strata in Shasta County, California; Trajanella colusaensis (Anderson, 1958) from upper Albian to Cenomanian strata in Shasta and Colusa counties, California; Trajanella californica (Gabb, 1864), from upper Cenomanian to Turonian strata in the Vancouver Island area of British Columbia, southwestern Oregon, northern California, southern California, and possibly Cedros Island of Baja California, Mexico; Trajanella Ursula (Anderson, 1958) from Coniacian strata in Shasta County, California; Western Society of Malacologists Annual Report, Vol. 36, p 36 and a new species from upper Santonian to lower and possibly middle Campanian strata in the Vancouver Island area, northern California, and southern California. Most of the Pacific Slope of North America species are represented by a few specimens, but when plentiful, there is variation in overall shape between juvenile and adults, with the last whorl of the adults becoming more cylindrical with growth. Overview of Late Cretaceous marine gastropods from the Chatsworth Formation, Simi Hills, Southern California Mary Stecheson Department of Geological Sciences, California State University, Northridge, 18111 Nordhoff St, Los Angeles, CA 91330 E-mail: stecheson@earthlink.net The marine Chatsworth Formation (middle Campanian to lower Maastrichtian) crops out in the Simi Hills of Los Angeles and Ventura counties, southern California. Most of the exposed formation consists of non-fossiliferous deep-sea fan deposits, but some exposures consist of fossiliferous slope facies. Molluscan fossils have been known and collected from these slope deposits for almost 100 years, but have not been studied in detail until now. This study of the gastropods is based on specimens from the Los Angeles County Natural History Museum’s Invertebrate Paleontology Collection and is currently ongoing. Fossil localities are most numerous in Bell and Dayton canyons, near the stratigraphic bottom of the exposed section in the southeastern Simi Hills. Fossils are not found in living positions, but were transported by slope failures or turbidity flows and concentrated in beds at bathyal depths (Almgren, 1981). The fauna is diverse, consisting of mollusks, crinoids, brachiopods, crabs, shark teeth and possible worm tubes. Preservation is typically moderate to poor, and many specimens are broken. About 20 gastropod families, 30 genera and 35 species are represented in the collections. In addition, there are several undescribed new species. The most common genera are: the ringiculid Biplica; the trochid Atira; naticids Gyrodes and Euspira; aporrhaids Anchura and Lispodesthes; three species of Turritella; and the perrissityid Perissitys. Possible new taxa may include representatives of three fasciolariid genera: Graphidula, Anomalofusus and Fusinus. Although the gastropod fauna of the Chatsworth Formation is indicative of a warm-water, shallow-shelf environment, taxa characteristic of tropical Tethyan waters have not been recovered. Water temperatures were probably warm-temperate in the area and may reflect cooling during the middle Campanian. Compared to other west coast Upper Cretaceous formations which have yielded one or more of the Chatsworth Formation gastropods, the Chatsworth gastropod fauna is most similar to that of the Campanian strata in the Santa Ana Mountains, Orange County, California. About two- thirds of the Chatsworth Formation gastropods are also found in the lower upper Campanian Pleasants Sandstone of the Williams Formation and the middle Campanian Holz Shale of the Ladd Formation in the Santa Anas. This is attributable to the geographic proximity of the Simi Hills and Santa Ana Mountains during the Late Cretaceous (Link, Squires and Colburn, 1984). Western Society of Malacologists Annual Report, Vol. 36, p 37 References Almgren, A. A. 1981. Foraminifera of the Chatsworth Formation, in Link, M. H., Squires, R. L. and Colburn, I. P., eds, Simi Hills Cretaceous turbidites: Los Angeles, California, Pacific Section, Society of Economic Paleontologists and Mineralogists, Fall Field Trip Guidebook, p. 43-50. Link, M. H. Squires, R. L. and Colburn, I. P. 1984. Slope and deep-sea fan facies and paleogeography of Upper Cretaceous Chatsworth Formation, Simi Hills, California: American Association of Petroleum Geologists Bulletin, v. 68, p. 850-873. Western Society of Malacologists Annual Report, Vol. 36, p 38 FOSSIL GASTROPODS FROM THE CHATSWORTH FORMATION Trochidae Rafinesque, 1815 Subfamily Margaritinae Alira ornatissima (Gabb, 1864) Zygopleuridae Wenz, 1938 Zehalia suciaensis (Packard, 1922) Turritellidae Loven, 1847 Turritella chicoensis Gabb, 1 864 Turritella chicoensis pescaderoensis Arnold, 1 908 Turritella ossa Popenoe, 1937 Aporrhaidae Gray, 1 850 Anchura phaba Elder and Saul, 1996 Lispodesthes rotundas (Waring, 1917) Teneposita laeva Loch, 1 989 Perissityidae Popenoe and Saul, 1987 Forsia popenoei Saul, 1988 Murphitys corona (?) Popenoe and Saul, 1987 Perissitys brevirostris (Gabb, 1864) Perissitys pacifica Popenoe & Saul, 1987 Zinsitys kingii Sau\, 1988 Calyptraeidae Lamarck, 1 809 Lysis suciensis ( Whiteaves, 1 879) Ampullinidae Cossman, 1918 Ampullina packardi Popenoe, 1937 Epitoniidae Berry, 1910 Acirsa nexilia 1889) Belliscala suciense (Whiteaves, 1879) Opalia? mathewsonii (Gabb, 1864) Buccinidae Rafinesque, 1815 Eripachya ponderosa (Gabb, 1864) Pentzia hilgardi (W\/h'\te, 1889) Fasciolariidae Gray, 1853 Anomalofusus sp. "Fusus ” tumidus Gabb, 1 864 Graphidula sp. Volutidae Rafinesque, 1815 Volutoderma averillii (Gabb, 1864) Volutoderma sp. a Volutoderma sp. b Mathildidae Dali 1889 Mathilda? Semper, 1 865 Acteonidae d’Orbigny, 1842 Neoacteonina obesa Dailey & Popenoe, 1966 Ringiculidae Philippi, 1853 Biplica obliqua (Gabb, 1 864) Scaphandridae Sars, 1878 (=Cylichnidae A. Adams, 1850) Ellipsoscapha nortonensis (Anderson, 1958) Naticidae Forbes, 1 838 Siphonariidae Gray, 1 840 Euspira compressa (Waring, Vasculum obliquim White, 1 889 1917) Gyrodes (Sohlella) canadensis (Whiteaves, 1903) Gyrodes {Sohlella) pacificus Popenoe, Saul & Susuki, 1987 Cassididae Latreille, 1 825 Haydenia impressa (Gabb, 1 864) Western Society of Malacologists Annual Report, Vol. 36, p 39 III. PHYLOGENETICS SYMPOSIUM Organized by Doug Eemisse California State University, Fullerton Genetic signatures of patellogastropod dispersal Emina Begovic Department of Integrative Biology, 1101 Valley Life Sciences Building, University of California Berkeley, CA 94720 E-mail: emina@socrates.berkeley.edu The ecological effects of larval dispersal capabilities in marine invertebrate life histories have long been recognized, but their implications for evolutionary events such as speciation, extinction, and genetic population structuring, have only recently been experimentally studied using molecular data. We sampled the cytochrome oxidase I gene (COI) from three North Pacific patellogastropod species co-occurring on coralline substrates in the nearshore subtidal throughout the Aleutian Islands, Alaska. Tectura testudinalis, Erginus sybaritica and Erginus apicina all feed on coralline algae, however T. testudinalis is a broadcast spawner while E. sybaritica and E. apicina are brooders. We hypothesized that these differences in reproductive strategy would be reflected in each species’ genetic population structure. Taxa were chosen based upon their similar biogeographic range, presumed ecological similarities and phylogenetic position. COI data indicate that population structure is directly affected by reproductive life history strategies when the ecological context of the study organisms is held constant and phylogenetic effects are accounted for, giving us a better measure of dispersal’s contribution to population structure. Octopod molecular phylogeny Cendrine Hudelot* and F. G. Hochberg^ ' University of Manchester, Stopford Building, Oxford Road, Manchester M 1 3 9PT, UK E-mail: cendrine.hudelot@man.ac.uk ^ Department of Invertebrate Zoology, Santa Barbara museum of Natural History 2559 Puesta del Sol Road, CA 93105 E-mail: fghochberg@sbnature2.org Octopod systematics is difficult and at present still unstable. The most recent classification published (Sweeney and Roper, 1998) is largely based on the presence or absence of a very few morphological characters. Morphologists argue about the diagnostic importance and reliability of most of the morphological and anatomical characters. They are scarce in octopods and many other characters are under discussion or need to be critically redefined. Western Society of Malacologists Annual Report, Vol. 36, p 40 Molecular techniques have proved to be powerful tools to resolve phylogenetic relationships. They also provide an independent approach to test hypotheses based on morphological analyses. We are currently reviewing the octopod systematics using both approaches in order to draw stable and reliable phylogenetic relationships and taxa diagnoses. We present here the results of the molecular investigations using the 3 ’end of the LSU rRNA gene (16S, around 500bp) for the Cirroctopoda and the catch-all genus Octopus (3 of the 4 species-groups recognised). The molecular marker used is able to resolve well the Cirroctopoda relationships. Revisions in the systematic classification of cirrates have been proposed (Piertney et. al., 2003). - Cirrothauma, Cirroteuthis and Staiiroteuthis : to be united in the Cirroteuthidae - Opisthoteuthis ; to be in the Opisthoteuthidae - Cirroctopus : to be placed in a new family The resolution power of the gene used is not giving as well supported results in the case of the genus Octopus. However, based on both morphological and molecular investigations we were able to propose some important clarifications of the octopod classification (Hudelot et al., in prep). - Eledone palari ; to be placed in new genus A. - Aphrodoctopus : to be reassigned to the genus Eledone - "aegina species-group" species : to be placed in the genus Amphioctopus - "macropus species-group" species : to be placed in the genus Callistoctopus - genus Octopus sensu stricto : to be redefined These are only the preliminary results and octopod systematics is likely to undergo major changes in the future years. References Sweeney, M. J. and Roper, C. F. E. 1998. Classification, type localities, and type repositories of recent Cephalopoda. In N. A. Voss, M. Vecchione, R. B. Toll and M. J. Sweeney (Eds.), Systematic and biogeography of cephalopods (pp. 561-599). Smithsonian Contributions to Zoology, No 586. Piertney, S. B. Hudelot, C. Hochberg, F. G. and Collins, M. A. 2003. Phylogenetic relationships among cirrate octopods (Mollusca : Cephalopoda) resolved using mitochondrial 16S ribosomal DNA sequences. Molecular Phylogenetic and Evolution, 27, 348-353. Hudelot, C. Boucher-Rodoni. R. and Hochberg, F. G. A preliminary review of octopod (Mollusca, Cephalopoda) systematics using the 3’ end of the LSU rRNA gene, in prep. Western Society of Malacologists Annual Report, Vol. 36, p 41 Host choice and genetic divergence in sacoglossan populations Patrick J. Krug Department of Biological Sciences, California State University Los Angeles Los Angeles, CA 90032 E-mail: pkrug@calstatela.edu The oceans pose special challenges for understanding speciation. Planktonic larval stages achieve considerable dispersal for many marine organisms, facilitating gene flow between populations. However, despite potential widespread mixing of propagules, molecular studies often reveal cryptic species in the sea. Theory holds that habitat preference can promote reproductive isolation, even in sympatry, but examples are lacking. The opisthobranch Alderia modesta is a cosmopolitan species found on its obligate adult host, yellow-green algae in the genus Vaucheria. Larvae settle in response to carbohydrates produced solely by the host alga. Recent studies have revealed a cryptic break between populations of A. modesta in the Pacific northwest. Populations south of Morro Bay have small adults that express a reproductive polymorphism, producing either planktotrophic or lecithotrophic larvae; populations from northern California and Oregon have large adults that produce exclusively planktotrophic larvae. Allozyme surveys showed that different alleles were nearly fixed in northern and southern populations, indicating a lack of gene flow despite the potential for larval transport via along- shore currents. Populations from Oregon and southern California were 18-20% divergent at the DNA sequence level, indicating prolonged isolation and probable cryptic speciation. Preliminary bioassays indicate that larvae from Californian parents do not settle on Vaucheria from Oregon, suggesting that appropriate settlement cues may only be locally available for larvae of these co-evolved habitat specialists. Being non-reproductive, larvae can move between habitats without causing gene flow if metamorphosis does not occur; any block to larval settlement will therefore generate pre-mating isolation. Behavior promoting habitat fidelity may thus result in differentiated populations despite the potential for migration in marine ecosystems. Comparative phylogeography of two eastern Pacific eelgrass mollusks - Taylor’s seahare {Phyllaplysia taylori) and the painted limpet (Tectura depicta) Kristina D. Louie and David K. Jacobs Department of Organismic Biology, Ecology and Evolution, University of California Los Angeles, CA 90095 E-mail: kdlouie@ucla.edu Eelgrass habitats along the Eastern Pacific are threatened ecosystems. Both direct habitat loss and anthropogenically induced modification through eutrophication, dredging, filling and pollution have resulted in declines of many of the organisms that depend on these habitats. We investigated the effect of reproductive strategy on genetic structure in two eelgrass specific mollusks, Taylor’s seahare {Phyllaplysia taylori) and the painted limpet {Tectura depicta). The Western Society of Malacologists Annual Report, Vol. 36, p 42 seahare utilizes direct development, while the limpet presumably employs planktonic larval dispersal. We obtained mitochondrial DNA cytochrome b sequence data from northern Vancouver Island to Southern California for the seahare, and from central and southern California for the limpet. Our data for the seahare suggest geographic structure that corresponds to zoogeographic breaks of other marine and estuarine taxa of the eastern Pacific. Our data for the limpet indicate significant genetic structure that corresponds to morphology. The role of molecules in understanding moliuscan evolution Monica Medina Genomic Diversity, Joint Genome Institute, 2800 Mitchell Drive, B400, Walnut Creek, CA 94598 E-mail; m_medina@lbl.gov The phylum Mollusca is one of the largest animal phyla, with diverse body plans and an extensive fossil record. Some of the moliuscan classes are so modified that phylogenetic reconstruction within the phylum, based on morphological characters has been controversial. With the advent of molecular techniques, sequence data has become an alternative source of phylogenetic characters. Initially, nuclear ribosomal small subunit (18S) data was widely used, mainly to understand the relationship of molluscs with other protostome groups. Recently, 18S data have been used to investigate relationships between the different classes. A few other gene fragments have been used to address relationships within certain classes. In addition to the sequence data, developmental genes and mitochondrial gene order data have become available for several groups. I intend to provide an overview of the current status for the different types of molecular data and what direction research is taking in the study of moliuscan evolution. So what is a species anyway? - A phylogenetic approach using cowries Christopher P. Meyer Florida Museum of Natural History, University of Florida, Gainesville, FL 3261 1 E-mail: cmeyer@flmnh.ufl.edu The question, “What is a species?” has plagued evolutionary biologists for centuries. In the study of cowries, this question has often been reworded and asked, “So is XX a valid species or not?” or “So how many species are there?” By far, because of the group’s familiarity, these questions dominate; and molecular approaches are perceived to provide the answers. Using a large comparative molecular database, I will establish objective criteria based on monophyly, coalescence, divergence and geography for recognizing evolutionary significant units that may, or may not, be eonsidered species. Evidence will be presented that demonstrate how the same data can be interpreted differently by both lumpers and splitters. Moreover, I will show how additional data can overturn initial assumptions, how comprehensive sampling matters, and why we are hung up on the issue. In the end, I conclude that, depending on one’s question, the “species” really may not matter if it is the process one wishes to explain. Western Society of Malacologists Annual Report, Vol. 36, p 43 IV. OPISTHOBRANCH SESSION Reports from the field: Bridging the gap between recreational scuba divers and scientists Mary Jane Adams Natural History Museum of Los Angeles County, 900 Exposition Boulevard Los Angeles, CA 90007 E-mail; divepng@yahoo.com Thousands of recreational scuba divers and dive guides observe marine life all over the world every day. A lot of these divers have a keen interest in marine biology. Opisthobranchs are easy to observe and photograph and many divers find them especially attractive. Reports and photographs from sport divers can document the distribution, size and color variations of opisthobranchs. Anyone with an interest in marine wildlife can record sightings and behaviors such as crawling, swimming, hunting, feeding, courting, mating and spawning. Reports of rarely seen species are particularly valuable. Scuba divers have been the first to document many species new to science. Most dive guides have extensive knowledge of the fauna in their area and can be important sources of information. Since the cost of field trips to remote locations is very high, reports from recreational divers and dive guides can be a valuable asset to science. Until recently, the information and images recorded by sport divers have not been available to the scientific community. The Internet has become an important way for marine naturalists to share their findings with the marine scientists. The author will present recent opisthobranch findings from the Solomon Islands, Indonesia, the Phoenix Islands, Thailand and Myanmar. The gtnus Annina (Gastropoda: Nudibranchia: Arminidae) in the western Atlantic: New species and a phylogenetic analysis If 2 Nestor E. Ardila and Angel Valdes ' Museo de Historia Natural Marina de Colombia, Instituto de Investigaciones Marinas INVEMAR, Santa Marta, A. A. 1016, Colombia E-mail; nardila@invemar.org.co ^ Natural History Museum of Los Angeles County, 900 Exposition Boulevard Los Angeles, CA 90007 E-mail; avaldes@nhm.org With more than 50 nominal species, Armina is the species-richest genus of the family Arminidae, and includes the most derived forms of the group. Features shared by members of this genus are the continuous anterior mantle margin, the presence of branchial and hyponotal lamellae, and the close distance between the rhinophores. Although Armina exhibits a world- wide distribution, only five species have been recorded in the western Atlantic. However, the western Atlantic record of Armina tigrina Rafinesque, 1814, needs confirmation (Ardila & Western Society of Malacologists Annual Report, Vol. 36, p 44 Valdes, 2004). Southern Caribbean members of the nudibranch genus Armina Rafinesque, 1814 are reviewed. Annina Juliana Ardila and Diaz 2002 and Armina muelleri (Ihering, 1886), two previously described species, are redescribed and the reproductive systems illustrated. A new species, Armina n. sp., is described based on a single specimen collected from Colombia. The number of notal ridges, the size and the shape of the radular teeth, the features of the masticatory processes, and the morphology of reproductive system are the main distinguishing characteristics between the new species and other Atlantic members of this genus. Armina n. sp. is the second species of the family Arminidae described from the Caribbean of Colombia. A phylogenetic analysis provides support for the hypothesis that Armina is a monophyletic group and that A. Juliana, A. muelleri, and the new species belong in this group. References Ardila, N. E. and Diaz, J. M. 2002. Armina Juliana (Nudibranchia: Arminoidea: Arminidae), a new species from the southern Caribbean. Boletin de Investigaciones Marinas Costeras, 31 : 25-31. Ardila, N.E. & Valdes, 2004. The gQwus Armina (Gastropoda: Nudibranchia: Arminidae) in the Southern Caribbean, with the description of a new species. Nautilus 1 18: 131-138. Biogeographic patterns of opisthobranch mollusks in the Gulf of California: Dispersion or vicariance? Orso Angulo Campillo Departamento de Biologia Marina, Centro Interdisciplinario de Ciencias Marinas Institute Politecnico Nacional, Avenida I.P.N. s/n, Colonia Playa Palo de Santa Rita, C.P. 23096, A.P. 592, La Paz, B.C.S. Mexico E-mail: oangulo@uabcs.mx The disjunct distribution of opisthobranch mollusks in the Gulf of California may be explained by two hypothesis: vicariant events that took place in the past, forming the Gulf of California, and the last glacial period, or a dispersal process involving “gaps” that function as biographical boundaries between known distributional centers (Californian and Panamic). Unfortunately, no solid evidence is available (fossil record), just “abnormal” records of species that have been found at long distances from their expected geographic ranges. These records may be evidence of the capability of opisthobranchs to be transported to other areas. Western Society of Malacologists Annual Report, Vol. 36, p 45 Temporal and spatial variations of the Opisthobranch Fauna near La Paz, Baja California Sur, Mexico Orso Angulo Campillo , Juan Elorduy Garay , and Hans Bertsch ' Departamento de Biologia Marina, Centro Interdisciplinario de Ciencias Marinas Institute Politecnico Nacional, Avenida I.P.N. s/n, Colonia Playa Palo de Santa Rita, C.P. 23096, A.P. 592, La Paz, B.C.S., Mexico, E-mail: mol@cromwell.com. mx ^ Mailing address: 192 Imperial Beach Blvd. # A, Imperial Beach, CA 91932, USA E-mail: hansmarvida@sbcglobal.net The ecological study of opisthobranch communities is fairly recent, often due to their small size, low abundance, lack of knowledge of preferred habitats, and nontraditional (that is not transect and quadrat) research methodology. In the past, these reasons have excluded them from more common quantitative studies of marine fauna. The majority of studies done on this group are taxonomic, although some have briefly mentioned aspects like type of substrate, depth, food and type of eggs. Our three study sites were near La Paz (Calerita, Punta Pericos and Isla Cerralvo), with intertidal and subtidal habitats. We made monthly samplings from October 2000 to October 2001. We counted 1575 total organisms distributed among 74 species, of which nine are present in the four habitats, three exclusive to Calerita (intertidal), five to Punta Pericos (intertidal), ten to Isla Cerralvo (subtidal) and thirteen to Punta Pericos (subtidal). Six new range extensions were found. The Shannon diversity index does not show any temporal tendency, the cluster analysis shows a slight similarity between the subtidal regions (49%), and for the intertidal the similarity is greater (53%). The results indicate that the dispersion of data (diversity values), as well as the fluctuations between orders in each locality, are determined by the temperature and the substrate in each of them. Preliminary phylogeny of the genus Thordisa Bergh, 1877 (Discodorididae, Doridacea, Nudibranchia) with descriptions of six new species Jamie M. Chan Department of Invertebrate Zoology and Geology, California Academy of Sciences Golden Gate Park, San Francisco, CA 94118 E-mail: jchan@calacademy.org The dorid genus Thordisa Bergh, 1877, shares digitiform oral tentacles and a notched and bilabiate anterior foot with all members of the clade Discodorididae. The characters traditionally used in taxonomy to assign species to the genus Thordisa are: 1) pectinate marginal teeth, and 2) conical papillae on the dorsal notum. So far, thirty-three nominal species have been described. Western Society of Malacologists Annual Report, Vol. 36, p 46 but no general taxonomic revision is available. Here, 1 provide the re-description of several species and the description of six new species. External morphology and complete internal anatomy (including radula and reproductive system) were investigated with dissection and SEM. A preliminary cladistic analysis confirms the monophyly of Thordisa. Phylogenetic relationships between species included in this analysis are proposed. Biogeographical distributions are discussed in a historical perspective. Phylogeny of Halgerda (Mollusca: Gastropoda) contrasting mitochondrial DNA (COl) and morphology Shireen Fahey California Academy of Sciences, Golden Gate Park, San Francisco, CA 94118, USA E-mail: shireen896@hotmail.com School of Molecular and Microbial Sciences, Unversity of Queensland Brisbane, Queensland 4072, Australia A phylogeny of the nudibranch Halgerda is presented based on mitochondrial COl and compared to a morphology-based phylogeny. Both separate and combined analyses resulted in trees that were very similar in topology, both to each other and to the previously published morphology-based tree albeit with lower consistency and retention indices. Some differences are noted in the topology based on the optimality criteria used: parsimony and maximum likelihood. Results of this study indicate that the COl gene contains sufficient phylogenetic signal for inferring species-level phylogeny in the Nudibranchia and also supports many of the clades in the morphological phylogeny. Specifically, the more basal clades of the morphology-based phylogeny are supported with differences noted at the most terminal taxa. Systematics and phylogeny of the nudibranch genera Okenia and Hopkinsia Terrence M. Gosliner Department of Invertebrate Zoology and Geology, California Academy of Sciences Golden Gate Park, San Francisco, CA 94118 E-mail; tgosliner@calacademy.org Representative species of Okenia, Hopkinsia and Sakishimaia were studied anatomically, including six undescribed species of Okenia from the tropical Indo-Pacific and four from the eastern Pacific. The addition of these undescribed taxa greatly expands our understanding of the anatomical variation present within Okenia. These studies demonstrate consistent differences in external body form, presence of oral glands, radular morphology and reproductive anatomy. These features were then subjected to phylogenetic analysis. The results of this study indicate that Okenia mediterranea (von Ihering, 1886) is the sister species to all other taxa studied. It retains several symplesiomorphies with the out group taxa of Goniodoris and Diaphorodoris. This species needs to be placed in a new genus to preserve the monophyly of the remaining genera. Okenia and Hopkinsia are sister taxa to each other. Sakishimaia is nested within Western Society of Malacologists Annual Report, Vol. 36, p 47 Hopkinsia and must be considered as a synonym of Hopkinsia in order to maintain the monophyly of all higher taxa. The suggested unique characteristics of the Sakishimaia are not evident in the present examination of material and the description of Sakasimaia kondoi is expanded here. It shares radular similarities with Hopkinsia hiroi and other features with other species of Hopkinsia. The evolution of ecological specialization of this clade on bryozoans and colonial tunicates is discussed within this phylogenetic context. Toward a phylogeny of chromodorid nudibranchs: Which questions can COI help answer? Rebecca F. Johnson Department of Invertebrate Zoology, California Academy of Sciences Golden Gate Park, San Francisco, CA, 94118 E-mail; rjohnson@calacademy.org Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064, The chromodorid nudibranchs are an amazingly diverse group, encompassing 1000 species. Most recent systematic studies of this group have either been simple descriptions of new species or have focused on similarly colored species from different genera (color groups). Gosliner and Johnson (1999) tested the monophyly of the genus Hypselodoris and identified morphological synapomorphies that separated hypselodorids from the rest of the chromodorids. We also presented a preliminary phylogeny of all of the chromodorids based on morphological data from the literature. We were not able to find consistent synapomorphies for every genus and we found a continuum of character variation across many different genera. Molecular markers may be helpful in separating some of these problematic groups. I have sequenced the mitochondrial cytochrome oxidase I gene for 30 chromodorid nudibranchs. I will present the preliminary phylogenetic results from this gene and discuss its usefulness in understanding relationships in this group. References Gosliner, T. M.and Johnson, R. F. 1999. Phylogeny of the monophyletic genus Hypselodoris (Molllusca: Nudibranchia; Chromodorididae) from the Indo-Pacific, with the description of twelve new species. Zoological Journal of the Linnean Society 125: 1-114. Western Society of Malacologists Annual Report, Vol. 36, p 48 The nudibranch family Eubranchidae from the eastern Pacific 12 3 Sandra Millen , Michael Schrodl , and Alicia Hermosillo-Gonzales ' Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, B.C., V6T 1Z4, Canada E-mail: millen@zoology.ubc.ca ^ Zoologisches Staatssammlung Miinchen, Miinchhausenstr. 21, 81247 Miinchen, Germany E-mail: schroedl@zi.biologie.uni-muenchen.de ^ Universidad de Guadalajara,Centro Universitario de Ciencias Biologicas y Agropecuarias Camino a la Tijera, Jalisco,Mexico E-mail: gueri25@hotmail.com Aeolid nudibranchs in the family Eubranchidae are small hydroid feeders with swollen cerata, a triserrate radula and an acleioproct anus. A number of genera have been proposed for the 38 described species. Most of these genera were subsequently synonymised into one genus, Eubranchus, prior to 1998 when Alexander Martynov revised the family into seven genera. This talk presents a phylogenetic analysis of the family with a suggested re-assignment of genera. The eastern Pacific species are briefly reviewed and several undescribed species are presented. The systematics of Roboastra Bergh, 1877 (Nudibranchia, Polyceridae, Nembrothinae) Marta Pola', Juan Lucas Cervera', and Terrence M. Gosliner^ ' Departamento de Biologia, Facultad de Ciencias del Mar y Ambientales, Universidad de Cadiz, Apdo. 40, 11510 Puerto Real, Cadiz, Spain E-mail: marta.pola@uca.es ^ Department of Invertebrate Zoology and Geology, California Academy of Sciences Golden Gate Park, San Francisco, CA 941 18, USA The genus Roboastra was described by Bergh (1877), with Roboastra gracilis as type species. A few species have been described since then, but some of them are currently regarded as synonyms. A review of the literature shows that there are five nominal species of Roboastra, but their original descriptions as well as a few additional published studies offer limited information. This lack of information has produced a great deal of confusion in the literature, including field guides and web sites, which often contain misidentified photographs. The genus Roboastra is characterized by having large oral tentacles developed as dorso- laterally grooved cylindrical projections equal in length to the rhinophores, radular rachidian teeth reduced, with three well-defined denticles, and a small prostatic gland confined to a coiled glandular section of the vas deferens (Bum 1967). Roboastra is distributed throughout tropical and temperate areas in the Atlantic, Eastern Pacific and Indo-Pacific. Western Society of Malacologists Annual Report, Vol. 36, p 49 The phylogenetic relationships within Roboastra are unknown, as well as the position of this group in the phylogeny of the phanerobranch dorids. In the present paper we conducted a preliminary review of the species included in this genus and a study of their phylogenetic relationships based on morphological characters. References Bergh, L. S. R. 1877. Malacologische Untersuchungen, Theil 2, Heft 1 1. Pp. 429-494, pis. 54-57 in Reisen im Archipel der Philippinen, C. Semper, ed. Kreidel, Wiesbaden. Bum, R. 1967. Notes on an overlooked nudibranch genus, Roboastra Bergh, 1877, and two allied genera (Mollusca: Gastropoda). Australian Zoologist 14: 212-221. V. GENERAL SESSION Biodiversity and biogeography of upper slope and continental shelf epifaunal molluscan assemblages from the Caribbean Sea Nestor E. Ardila Museo de Historia Natural Marina de Colombia, Instituto de Investigaciones Marinas INVEMAR Santa Marta, A. A. 1016, Colombia, E-mail: nardila@invemar.org. co Epifaunal mollusk data from the southern Caribbean (Colombian upper slope and continental shelf; 9 to 12° N, 71 to IT W) covering 69 sites in a range of water depths (20-500 m) were used to study assemblage patterns and spatial variability, and to evaluate different measures of diversity. A total of 13617 specimens were identified to species level and quantified. A total of 253 species was found, of which 126 (50%) of them are first records for the Colombian Caribbean and six species are new to science. Of these recorded species, 61% were restricted to one or two sites, and 43% were represented by one or two individuals. No species spanned the entire sampling area. Gastropods includes the greatest species number, followed by bivalve class. In terms of abundance, bivalves were the best represented. Multivariate analysis showed assemblages whose structure and composition seem to be mainly determined by depth and geographic gradient. Alpha diversity (sample species richness) was highly variable (2-29 species) and showed evidence of a relationship to a bathymetric gradient. Whittaker’s beta diversity measure (B, extent of change in species composition among stations), and multivariate measurements of beta diversity (number of shared species, complementarity and Bray Curtis dissimilarity) were strongly influenced by depth. Shallow assemblages (20-70 m) showed the highest beta diversity, while those deep assemblages (300 and 500m) showed the lowest beta diversity, but the highest alpha diversity. Finally, upper slope Colombian Caribbean malacofauna (300-500 m) have a broad distribution in the Tropical Western Atlantic, with only a small percentage exclusive to the southern Caribbean. This distributional pattern results from a reduced Western Society of Malacologists Annual Report, Vol. 36, p 50 rate of faunal change, because of broad dispersion of larvae, the greater antiquity of fauna in deep environments, and lower susceptibility to regional changes in the abiotic conditions. Comments on malacological research in the Gulf of California, Mexico Hans Bertsch Department of Invertebrate Zoology and Geology, California Academy of Sciences Golden Gate Park, San Francisco, CA 94118 192 Imperial Beach Blvd., # A, Imperial Beach, CA 91932 E-mail: hansmarvida@sbcglobal.net There is a rich tradition of malacological research within the Gulf of California. Most of the research done by Mexican institutions has focused on molluscs of commercial value, whereas U.S. researchers have tended to engage in more basic scientific research (taxonomy, natural history, biogeography, etc.). This presentation will discuss some of the expeditions and research projects by major United States institutions and individuals in the Gulf of California. It will also include anecdotal remarks about the individuals and their experiences. As John Steinbeck wrote, “This is a very holy place, and to question it is to question a fact as established as the tide” (Log from the Sea of Cortez, chapter 1 7). Particular emphasis will be placed on the central Gulf of California, especially from Bahia de los Angeles to the Loreto region (approximately 29°30’ N to 25®30’ N). Recent cultured Chinese fresh water pearls of various shapes please pearl buyers and sellers in America Beatrice Burch 3599 Sylvan Pines Circle, Bremerton, WA 98310 E-mail: taburch@attbi.com Geologically speaking, pearly Unionidae mussels only date back to the Tertiary time (Moore, 1969) falling just prior to the geologically Recent in Asia. The Tertiary period began about 25,000 years ago and the Recent period began about 15,000 years ago. In Asia today there are many freshwater bivalve Unionidae species of Mollusca, both small and some large enough to be of commercial importance Pearly shells are not restricted to fresh water bivalves (Burch 1995b). Indeed many marine mollusks are used commercially, especially the enormous Australian Pinctata maxima Jameson, 1901, in the marine family Pteriidae (Hedley, 1916). This has been used since the middle of the 1 880s for salad plates, butter spreaders, and pearl handled table knives. Other marine bivalves with mother of pearl include members of the families Mytilidae and Pinnidae (Burch, 1995a,b). Marine pearly gastropods include Trochidae and Haliotidae (Burch, 1995c). Other pearly marine mollusks include Cephalopoda, such as the Tertiary to Recent Spirula which is not used commercially and the larger Nautilus (Burch, 1995c) which are protected in Hawaii but are still used for ornaments elsewhere. Western Society of Malacologists Annual Report, Vol. 36, p 51 The enormous river system of China permits several freshwater species of the bivalve family Unionidae to be utilized commercially, although Cristaria plicata (Leach, 1814) is less common now due to long over-exploitation over the centuries. The Unionidae species used in China now is Hydriopsis bilata (Simpson, 1902) (Ward, 2002 p. 52). I first became fascinated by pearly objects in San Francisco’s Chinatown back in the 1920s. The Chinese have made pearly Buddhas since about 500 BC (Ward, 2002) by inserting images in freshwater mussels which were removed when they were covered with pearly nacre. These were sold individually as religious objects (but to me merely as pearly objects). They were five cents each, or six for twenty-five cents. Upon moving to Oahu, Hawaii in 1970, my husband (Thomas) and I began to gather nacreous objects such as mother-of-pearl salad plates, an umbrella handle, opera glasses, button hooks, etc., in antique stores in Honolulu, and in various cities when on visits to the mainland, and even on the internet’s eBay. We started attending the Douglas Merchandise and Jewelry wholesale shows in Blaisdell Center in Honolulu in 1979 and purchased a delightful Chinese freshwater pearl necklace. It is 34 inches long and consists of joined pairs of 4 mm white pearls (Plate 1, figure A). We enjoyed attending these Trade Shows and admired the conventional round pearls from Japan, Tahiti and other places in the Pacific. We even bought some from Tahiti but I preferred the Chinese and Japanese freshwater pearls. Also there were amazing Chinese freshwater mother-of-pearl gaming counters, (Burch, 1995d), probably modem, although mentioned in Desolation Island, one of Patrick O’Brian’s delightful sea stories of the Napoleon Bonaparte war in the late 1700’s and early 1800s. Another source for information on gaming counters is Seymour (1985). In 1994, Honolulu was chosen as the site for the First International Pearl Conference for professional pearl workers in freshwater and marine pearl industries. The conference was attended by 645 people from all around the world. It was an impressive combination of lectures and exhibits. I also met two pearl editors: Richard Torrey of Pearl World, an international journal, and Neil Sims of the Pearl Oyster Bulletin put out by a consortium from France and New Caledonia. The conference was managed by Crest International with local chairman Mr. C. Richard Fassler of the Hawaii Department of Land and Natural Resources, Aquaculture Development Program. As program chairman, Mr. Fassler asked me to prepare an exhibit on pearls. So, with the help of my husband, my daughter (R. Janthina DuSavage) who sent us labels and graphics from her home in Washington, Regina Kawamoto of the Mollusca department and Arnold Suzumoto of the Fish department of the Bernice P. Bishop Museum of Cultural and Natural History (where I was a staff member), the contractor (Patrick Myers) working on our house, and zoological and Malacological friends from museums and universities around the world we prepared an exhibit using 16 glass and mahogany cases from the Hawaiian Malacological Society (Burch, 1994). Sadly only professionals in the pearling world were able to attend the conference but anyone could come and see the displays. Although the “Pearls 94” Conference brochure had photographs of unusually shaped pearls, it wasn’t until 1997 that the vendors at the Douglas Trade Shows began to include such pearls for sale. Omar’s Wholesale Black Tahitian Pearl Company had four small exquisite deeply lustrous and gorgeously oriented small white pearl sticks, overlying two or more fancy shaped sticks. Also at the LuCcoral Museum in Honolulu was a pearly dragon fly (plate 1, fig. B) and I realized people were working on a new form of pearl. In 1999 while at the Pacific Pearls booths, I saw Western Society of Malacologists Annual Report, Vol. 36, p 52 strikingly different Chinese freshwater pearls shaped like coins. Three of these are shown in plate 1, figure C. One is peach, one white, and one faintly pink. Thus along with booth after booth of gorgeous spherical pearls a new art form was beginning to appear. However it took until 2002 before the first printed notice of coin pearls were shown in Pearl World. Both the 2002 and 2003 April-May-June issues of Pearl World had dealer listings and summaries showing the number of dealers selling the following types of pearls at the Jewelry Show at Tucson, Arizona. 2002: 6 dealers had coin pearls. No dealers had other non spherical pearls. 2003: 13 dealers had coin pearls, 12 had baroque pearls and 12 dealers with other shapes. Lois Berger in the 2002 and 2003 Pearl World presented lists which, among other things, indicated that many dealers thought that the pearls were harvested too soon and had insufficient nacre. Only coin pearls had a very high luster and the flat rectangular pearls had strong orient. (Luster is the sharpness and intensity of images reflected from the pearl surface. Orient is the underlying deep iridescent play of color.) Pacific Pearls was one of the 13 dealers listed in Pearl World in 2002 and 2003 and in April 2003 Marcia Fentress of that organization agreed to send me an assortment of pearl necklaces and strands of fancy shaped pearls. I soon received a magnificent assortment. (All the pearls shown on plate 2 are from this shipment.) Included were many strands of non spherical shapes including picket fences, squares, rectangles, ovals, and double paired rounds. Some were dyed and some were natural color. A strand is 16 inches and a necklace may be either 16 or 32 inches. All have a mother-of-pearl nucleus cut to the desired shape which is implanted in the mussel and on which an additional nacreous layer is deposited. Also included in the shipment were paired stubs for earrings of two overlapping coin pearls. Other non spherical pearls included were a strand of white rhomboid 9x15 mm drilled point to point along the long axis, one 34" necklace of white rectangular 9x15 mm pearls drilled along the long axis, a beautiful 16 mm coin necklace with a modified top, two beautiful single unblemished 16 and 18 mm peach coins, two slightly overlapping pairs of 12 mm white coins. Also there were two squares which were highly lustrous and both sides with great orient. Last of all there was one Kasumi ga-ura, a Japanese freshwater pearl solitary, almost a spherical 14 mm pearl. This last was an indication of what Japanese freshwater pearls can be. A later shipment in July 2003 from Marcia Fentress and Fuji Voll, co-owners of Pacific Pearls, shows that in addition to the Chinese pearls discussed above there also will be an increased supply of Japanese freshwater pearls and shells that will furnish enjoyable new jewelry involving man and his imaginative jewelry for American buyers. References Burch, Beatrice L. 1994. Pearls ‘94: The First International Pearl Conference. Hawaiian Shell News vol. 42:1 1 p.l 1, 3 figs.* Burch, Beatrice L. 1995a. Pearly Shells Part 1. Living Bivalves: Origins and Relatives. Hawaiian Shell News vol. 43:2 p.6, 9 figs.* Western Society of Malacologists Annual Report, Vol. 36, p 53 Burch, Beatrice L. 1995b. Pearly Shells Part 2. Distribution of Nacreous and Subnacreous Bivalve Genera and Species. Hawaiian Shell News vol. 43:3 p. 4, 13 figs., 2 tables.* Burch, Beatrice L. 1995c. Pearly Shells Part 4. Monoplacophoa, Gastropoda, and Cephalopoda. Hawaiian Shell News vol. 43:5, 15 figs.* Burch, Beatrice L. 1995d. Pearly Shells Part 1 1. Mother-of-Pearl Yesterday and Today. Hawaiian Shell News vol. 43:12 p. 5, 17 figs.* Hedley, Charles, 1916. A preliminary Index of the Mollusca of Western Australia, (Pinctata maxima Jameson 1901 p. 6). Extract from Journal Royal Society Western Australia vol. 1. 1914-1915, pp 3-77. Moore, Raymond C. (editor), 1964. Treatise on Invertebrate Paleontology Part K, Mollusca 3 Cephalopoda. (Family Nautilidae p. K448, figs. 329-330) The Geological Society of America and the University of Kansas Press.519 pp. Moore, Raymond C. (editor), 1969. Treatise on Invertebrate Paleontology Part N, Mollusca 6 Bivalvia. (Pitariidae pp N302-N306, figs. C38-C39; Unionidae pp. N415-N463, figs. D17- D53) The Geological Society of America and the University of Kansas Press.489 pp. OBrian, Patrick, 1991. Desolation Island. (Gaming Counters p. 30) W. W. Norton & Co, New Y ork and London. Seymour, D. 1985. Antique Gambling Chips with price guide and chip codes. Past Pleasures, Los Altos, California. Ward, F. 2002. Pearls. Gem Book Publishers, 7106 Saunders Court, Bethesda, Maryland 20817. * These may be available from Mr. William Ernst, Corresponding Secretary, Hawaiian Malacological Society, 94-641 Hikianalia PI., Miliani, HI 96789. Western Society of Malacologists Annual Report, Vol. 36, p 54 Plate Explanations Plate lA. Necklace of joined pairs of 4 mm white pearls 34 inches long purchased in Honolulu in 1979. Plate IB. Pearl Dragonfly with 38 mm wings and a 40 mm body purchased from Lucoral Museum in Honolulu in 1997. Plate 1C. White, peach, and pink 14 mm coin pearls purchased from Pacific Pearls of Mill Valley, California in 1999. Plate 2A. A 16 inch strand of 13 mm salmon coin pearls purchased from Pacific Pearls of Mill Valley, California in 2003 Plate 2B. A 16 inch strand of grey dyed 12 mm square pearls strung tip to tip purchased from Pacific Pearls of Mill Valley, California in 2003. Plate 2C. A 16 inch necklace of 8 x 16 mm salmon picket-fence pearls purchased from Pacific Pearls of Mill Valley , California in 2003. Western Society of Malacologists Annual Report, Vol. 36, p 55 Western Society of Malacologists Annual Report, Vol. 36, p 56 Figure 2 Western Society of Malacologists Annual Report, Vol. 36, p 57 Withering syndrome in abalone from Baja California, Mexico Jorge Caceres-Martinez Laboratorio de Biologi'a y Patologia de Organismos Acuaticos del Departamento de Acuicultura Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Apdo. Postal 2732, Ensenada, Baja California, C.P. 22800 Mexico E-mail: jcaceres@cicese.mx Instituto de Sanidad Acuicola, Calle 9a y Gastelum No. 468 Local 14 Zona Centro Ensenada, Baja California, C.P. 22800 Mexico In 1992 the first data on the mass mortality of black abalone Haliotis cracherodii from the Channel Islands of southern California in the middle 1980s were published. Abalone populations were devastated along the islands; between the 95 and 100% of abalones were lost with mortalities spreading along the California coast. The epizootic spread of mortalities throughout the Channel Islands and to the coast of California suggested the role of an infectious etiological agent. Clinical analysis of abalone showed weakness, lethargy, shrunken appearance of foot muscle, mantle retraction, poor gonadal development, the inability to tightly adhere to the substrate and death. All these symptoms were collectively named Withering Syndrome (WS). In 1995 a strong pathogen-disease association was suggested. The pathogen was described as an intracellular rickettsia-like prokaryote (RLP). Several authors have admitted the association of RLP and WS indirectly by the injection of antibiotics in diseased abalone, and their subsequent recovery. The RLP was identified as a unique taxon and given the provisional status of "Candidatus Xenohaliotis californiensis Several years after detection of WS in California, USA, the question on the presence of this disease in Baja California, Mexico, began to appear. Some authors have recorded that some abalone exemplars from Mexico showed clinical signs of WS, and the presence of "Candidatus Xenohaliotis californiensis" has been confirmed. However, no records on mass mortality of black abalone or other abalone species in Mexico were documented in the mid-eighties or today. This work describes the studies on WS carried out in Mexico comparing their findings with those observed in California. Western Society of Malacologists Annual Report, Vol. 36, p 58 Reproductive cycle of the Japanese oyster Crassostrea gigas cultured in Bahia Falsa, Baja California, Mexico Jorge Caceres-Martinez, Rebeca Vasquez- Yeomans, Sergio Curiel-Ramirez Gutierrez, and Patricia Macias Montes de Oca Laboratorio de Biologi'a y Patologia de Organismos Acuaticos del Departamento de Acuicultura Centro de Investigacion CientiTica y de Educacion Superior de Ensenada Apdo. Postal 2732, Ensenada, Baja California, C.P. 22860 Mexico E-mail: jcaceres@cicese.mx The gonadal development of cultured oyster {Crassostrea gigas) was studied in Bahia Falsa, B.C., Mexico, from May 1996 to April 1997. Two localities were considered, and oysters were grouped in accordance with their positions in the upper, middle and lower levels of the cultivants. A general reproductive pattern exists, with some variations according to position. Ripe gametes reach maximum proportion in March and June, and empty follicles are present in maximum percentage during the reproductive season of May to August. From September to January, reserves accumulate and gametogenesis starts again in February. Thus gametogenesis starts in mid-winter, showing an increase in the proportion of developmental gametes. Reproductive season is from spring to summer, and reserve accumulation takes place in late summer to early winter. This pattern was more pronounced in the lower level of the cultivants in both localities, whereas the middle level of one location had ripe gametes almost all year round. The upper level showed an intermediate pattern. These patterns presumably match micro- environmental differences within the various levels. Phenotypes of the California mussel, Mytilus californianus Conrad (1837) Miguel A. del Rio-Portilla', Jorge Caceres-Martinez'’^’, Sergio Curiel-Ramirez Gutierrez', and Ignacio Mendez G6mez Humaran^ 'Departamento de Acuicultura del Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, A.P. 2732 C.P. 22860, Ensenada, Baja California, Mexico. ^Instituto Nacional de la Pesca, Pitagoras 1320 60 Piso, Col. Sta. Cruz Atoyac, C.P. 03310, Mexico D.F. ^Instituto de Sanidad Acuicola, A. C., Calle 9a y Gastelum #468-14 Zona Centro, Ensenada, Baja California, C.P. 22800 Mexico. The morphological variability of Mytilus edulis complex species has been the subject of a great variety of studies. However, the morphological variability of Mytilus californianus has not been studied. We found that there are some M. californianus without some of the shell characteristics mentioned in the original description of this species. The most remarkable difference was the absence of radial ribs on the exterior of the shell; thus, we tested the presence of at least two phenotypes in M. californianus. Six hundred ninety five M. californianus of different sizes were collected from the locations La Mina del Fraile, La Bufadora and La Salina in Baja California. For comparison, 58 M. galloprovincialis were collected from an aquaculture Western Society of Malacologists Annual Report, Vol. 36, p 59 facility at Rincon de Ballenas in Bahia de Todos Santos, Baja California. Fourteen morphometric measures and the weight of the shell were measured and a principal component analysis (PCA) and a logistic regression (LR) were carried out to find differences between mussels studied and for obtaining a prediction to assign the phenotypes. The presence of ribs, small ligament margin, a narrow posterior byssal retractor muscle scar and shell weight were the discriminating characters between two groups in M. californianus confirming the presence of at least two phenotypes in this species, which were present in all mussel sizes and the studied locations. The LR correctly assigned 99.28% of the shells to each phenotype, and it considered only eight out of the fifteen morphometric measures. The PCA showed a clear morphological difference between both phenotypes of M californianus and M. galloprovincialis. The original description of this species by Conrad in 1837 was done taking into account only the phenotype with ribs. Life history traits and reproductive behavior in Ariolimax spp. (Arionidae: Stylommatophora) Janet L. Leonard, Erica Mendieta, and John S. Pearse Joseph M. Long Marine Laboratory, University of Califomia-Santa Cruz Santa Cruz, California 95060 E-mail: Jlleonar@cats.ucsc.edu The genus Ariolimax includes five described taxa. In addition to the genital characters on which the original descriptions were based, the taxa have been found to differ in life history characteristics and sexual behavior. Egg size does not correlate with growth rate across species, and our data from Ariolimax columbianus columbianus are inconsistent with Shibata and Rollo’s (1988) finding that within a clutch, growth rate is inversely proportional to egg size. The mean growth rate A. c. columbianus (over 16 weeks) is greater than that of either columbianus stramineus or. A. dolichophallus, which have similar growth rates. They also differ in their sexual behavior. In ^4. californicus californicus and A. dolichophallus copulation is proceeded by a period of courtship involving reciprocal biting and headswinging which lasts approximately 2 hrs. and may last more than 5 hr. In c. stramineus, copulation is proceeded by a very brief courtship phase (<20 min) which may involve biting and a few low amplitude head movements. Copulation in^. c. stramineus is usually simultaneously reciprocal (3/4) and lasts 1-2 hr. Four instances of heterospecific copulation between A.c. californicus and^. c. stramineus have been observed so far whereas copulation between A.c. californicus and A. dolichophallus has only been observed once in several years of observation. Whether fertile offspring are produced in either case is as yet unknown. Western Society of Malacologists Annual Report, Vol. 36, p 60 Status report on: “Shell-bearing Gastropoda of the Northeastern Pacific” James H. McLean Natural History Museum of Los Angeles County 900 Exposition Boulevard, Los Angeles, CA 90007 E-mail: jmclean@nhm.org The poster with the title “Progress toward completion of taxonomic reference manual: Shell- bearing Gastropoda of the Northeastern Pacific,” which accompanies this talk, was prepared a year ago and was shown at WSM and AMS meetings for the year 2002. Text used in the poster provides a broad outline of the project; this same text appears in my current poster abstract. Here I confine myself to an actual report on the progress, now that the funding period from the Packard Foundation is well into its second year. In addition to the poster, the are five binders displayed on tables, showing the text for the two prospective books (northern and southern), and numerous binders containing captions and prints made by Michelle Schwengel, who is my thoroughly talented imaging collaborator supported by the Packard Foundation. The prints have been made by the scanning of my negatives, with adjustments in PhotoShop. The prints are attached to the contact proof print along with a draft copy of the text for the caption and a copy of the museum label for each specimen intended for illustration. So far (May 2003) there are approximately 3,000 images stored on hard disk, including those for all the new species (of which there are at least 400), plus the images for use in the forthcoming revised edition (J. Carlton, ed.) of “Intertidal Invertebrates of the Central California Coast,” and images for the most speciose and taxonomically challenging families, including Fissurellidae, Turbinidae, Trochidae, Muricidae, Buccinidae, and Turridae. Photos have been selected for the Columbellidae and the Fasciolariidae. I had originally assumed that selection of specimens for illustration would be a rapid process, but instead have found that it is time-consuming because many new photos have to be done in order to show specimens that document the possibilities of variation. There is now a separate voucher collection for the LACM specimens to be figured. What I did not expect (although perhaps I should have) was that this process would continuously bring further new species to my attention, all of which are intended to be described in the book. In my student days I could not have imagined that so many new species would come to light. In those days I had the impression that the whole fauna had been ovemamed and that it was my duty to reduce the number of names. Now I am resurrecting some of the names I had previously thought to be superfluous, but many more of my new species are based on material not available in the older collections, instead based on material resulting from more recent collecting expeditions, including expeditions to the outer coast of Baja California, abyssal material from Oregon, and material recovered during exploratory fishery monitoring in Alaska, including the Aleutian Islands. I have attempted to update the text for each family during the process of selecting specimens, but have found it difficult to maintain the pace for image selection and updating the text at the same time, so in some cases I have had to settle for improving the state of the outline before Western Society of Malacologists Annual Report, Vol. 36, p 61 moving to the next family. It is clear, however, that once all the illustrations are on hand, it will be a rapid process to flesh in the outline to turn it into finished text. The amount awarded by the Packard Foundation was half of what I had asked, so it has been half-time work for Michelle during the two year period for the award. Unfortunately, it has now become apparent that more funding (to bring it to the amount originally requested) will be needed to finish the task of bringing the southern book and subsequently the northern book to a stage ready for publication. All specimens needed for illustration in the southern book have been photographed or are already at hand, which makes it possible for me to move unimpeded; however, I will have to request specimens or images or travel to distant museums to get access to material from the northwestern Pacific required for the second book. Finally, I have to comment on the dearth of funding for works of this kind. Although there is certainly a market for my efforts and its importance to collectors, resource managers, and those who conduct the many phases of research on marine gastropods, need hardly be mentioned - specific federal funding programs for those with the expertise and museum resources to produce taxonomic manuals remain non-existent. When I was a student, those with an interest in classifications received a modicum of the funding. At this point there is funding only for those purposes for which the thrust is phylogeny, while the working classifications and the production of shell books is considered best left to the advanced amateurs to conduct as commercial ventures. NSF provides funding for collecting in endangered habitats (through its Surveys and Inventories program), and there is money for biodiversity monitoring and for the participants in the endless meetings among those who envision vast databases of the world’s biota. Having devoted much of my career, as well as the first two years of my “retirement” toward the successful completion of my objectives, I hardly relish the prospect of again having to worry about funding. However, one way or another, this job will be finished. To chew or eschew— apophallation in Ariolimax as a result of sexual conflict? Brooke Miller Department of Ecology and Evolutionary Biology, D450 Earth and Marine Sciences University of California, Santa Cruz, CA 95064 E-mail; miller@biology.ucsc.edu Sexual conflict between mating partners can lead to behavioral strategies where individuals act to manipulate the behavior of their mating partner. The majority of work in this field has focused on gonochoristic animals, those with separate male and female sexes. However, simultaneous hermaphrodites, animals capable of producing both eggs and sperm at the same time, have recently been suggested as being more likely to evolve partner manipulation strategies. Since hermaphrodites are driven to remate through both male and female function, they may be selected to be more promiscuious than gonochroistic females. Greater promiscuity leads to greater sperm competition, as subsequent matings introduce rival sperm. It is therefore thought that partner manipulation tactics that reduce future sperm competition frequently evolve in hermaphrodites. This study focuses on the unusual mating behavior of penis chewing, termed apophallation, that is observed in some species of Banana slugs. I propose that apophallation serves as an adaptive partner manipulating strategy to reduce sperm competition, and am currently using the Western Society of Malacologists Annual Report, Vol. 36, p 62 species Ariolimax doIichophaUus Mead as a study organism to test my predictions. I will be discussing current progress on my work, as well as future directions. Some families of “prosobranch” Mollusca from Mexico Edna Naranjo-Garcia Departamento de Zoologi'a, Institute de Biologia, U.N.A.M. Apartado Postal 70-153, Mexico, D.F. 04510 Mexico E-mail: naranjo@servidor.unam.mx Preparation of the catalogue of the non-marine mollusks of Mexico (based on bibliographic sources) has been undertaken. As part of that project three prosobranch families are presented here. Nomenclatural problems were solved; the number of species in the country recorded to date was obtained, followed by the analysis of species distribution. The families treated are: Diplommatinidae (one species), Helicinidae (50 species) and Ceresidae (8 species). The three families are distributed in areas with high humidity (tropical rain forests). Members of Helicinidae also inhabit non-highly seasonal areas (temperature wise) while rainfall is strongly seasonal; vegetation types in that area are tropical deciduous and semideciduous forests. Those families are not distributed in temperate nor dry hot areas with Sonoran or Chihuahuan desert vegetation. Presence of giant polymorphic cells in Crassostrea gigas cultured in Bahia Falsa, Baja California, NW Mexico Rebeca Vasquez- Yeomans and Jorge Caceres-Martinez Laboratorio de Biologia y Patologia de Organismos Acuaticos del Departamento de Acuicultura Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Apdo. Postal 2732, Ensenada, Baja California, C.P. 22800 Mexico E-mail: jcaceres@cicese.mx Instituto de Sanidad Acuicola, Calle 9a y Gastelum No. 468, Local 14 Zona Centro, Ensenada, Baja California, C.P. 22800 Mexico The culture of the Japanese oyster Crassostrea gigas is a successful commercial activity in Northwest Mexico. Since 1997 high mortality outbreaks have occurred in the area without apparent reasons. In this study we found gill erosions observed in clinical analysis, inflammation of the tissues at histopathological levels, and in some cases we detected the presence of giant polymorphic cells. In general, conditions mentioned above, including the presence of Trichodina sp. and specially the presence of giant polymorphic cells, match with the symptoms of the gill disease caused by an icosahedral DNA virus (GNV infection) first recorded in the Portuguese oyster Crassostrea angulata and in the Japanese oyster C. gigas in Europe. However, the Transmission Electron Microscopy (TEM) analysis of damaged tissues did not reveal the presence of viral particles. Western Society of Malacologists Annual Report, Vol. 36, p 63 VI. POSTER SESSION Beginnings of a new book on the marine bivalve mollusks of Tropical West America Eugene V. Coan and Paul Valentich-Scott Department of Invertebrate Zoology, Santa Barbara Museum of Natural History 2559 Puesta del Sol Road, Santa Barbara, CA 93105 USA E-mails: gene.coan@sfsierra.sierraclub.org and: pvscott@sbnature2.org Research has begun on a monograph covering the marine bivalve mollusks of tropical West America. The manuscript will document and describe all bivalves from the central Pacific coast of Baja California, Mexico, to northern Peru, as well as the offshore islands. It will encompass all habitats from the intertidal zone down to abyssal depths of more than 4,500 meters. The new monograph will detail approximately 800 species and include color photographs and/or line drawings of each, along with a description of its shell, habitat, and ecology, and references to relevant literature. A particular effort has been made to ensure the book’s utility to those outside this geographic area. In this regard, the monograph will contain copiously illustrated keys and character tables at the superfamily level and below. This volume will be a companion to Coan et al., 2000, which covers the bivalve fauna from arctic Alaska to northern Baja California. References Coan, E. V., Valentich Scott, P., and Bernard, F. R. 2000. Bivalve Seashells of Western North America. Santa Barbara Museum of Natural History Monographs 2, viii + 764 pp. The History of the Western Society of Malacologists Jody Woolsey and Barbara Chaney Conchological Club of Southern Califomia/San Diego Shell Club 3717 Bagley St., Los Angeles, CA 90034 USA E-mail: mjwoolsey@earthlink.net Past Historians, Barbara Chaney and Jody Woolsey, present a selection of WSM history scrapbooks from the WSM archives at the Santa Barbara Museum of Natural History. The condition of the early books reflects the lack of knowledge and availability of archival materials that are plentiful today. A conservation project aimed at preserving these for the future is in the planning stages. Of more immediate concern is a wish to fill in the missing years when there was no historian (or none, at least, that we are aware of). Please make a point to pick up the flyer that will be available at the display, which lists the years in question. Contact information for Jody Woolsey will also be on the flyer if you have photos and/or other memorabilia for any of the years that you can donate or loan for copying. Western Society of Malacologists Annual Report, Vol. 36, p 64 Shell-bearing Gastropoda of the Northeastern Pacific James H. McLean Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007 E-mail: jmclean@nhm.org [The poster for which this is the abstract was prepared in July 2002 for WSM and AMS meetings. This is a more detailed abstract than that previously published in program abstracts for those meetings. This is the text used in the poster] Introduction - Two volumes on shelled gastropods comparable to the highly acclaimed Bivalve Seashells of Western North America, by Coan, Scott and Bernard, published in 2000, are in advanced stages of preparation, to be published by the Natural History Museum of Los Angeles County. Southern volume - The first volume to be finished treats the species of British Columbia to central Baja California, the area of overlap with the tropical Panamic Province. Species of two faunal provinces are included, those of the subtropical Californian Province and those of the cool-water Oregonian Province. Endemic species from the outer coast of Baja California are included, but the more southern species ranging to Baja California, which were treated by Keen (1971), are excluded. Northern volume - The second volume treats the more northern species of Arctic Alaska, south to British Columbia and west to the Kurile Islands and Okhotsk Sea, Russia. This provides reasonable geographic limits and emphasizes the faunal distinctions and provincial radiations that distinguish the temperate and cold-water faunas of the northeastern Pacific. Many species occurring in Alaska range west to Russia and northern Japan. Species occurring in the Aleutian Islands tend to have more affinity to the fauna of the Kurile Islands than to the fauna of the Gulf of Alaska. Previous compilations - Carpenter (1857, 1864) first reviewed the molluscan fauna of the northeastern Pacific. Mollusks of the northeastern Pacific were last fiilly summarized in checklist form by Dali (1921), followed by Oldroyd (1927), who republished original descriptions and illustrations for the species listed by Dali. Abbott (1974) included all species, but many were only listed. Treatment of higher categories - All higher category taxa are fully diagnosed. A fully ranked classification is used; problems that arise in comparison with phylogenetic classifications are noted. Type species and manner of designation are given for the genera. References are provided (following the generic synonymy) for recent authors whose generic concepts are similar to my usages. Species treatment format - Synonymies provide reference to the original description and illustrations for the nominal taxa and synonyms. Type localities and type specimen repositories for nominal taxa and all synonyms, as well as citations of subsequent illustrations of type specimens are included within brackets in the synonymies, providing the essential information for the data-basing purposes of future workers. The text for each species includes a brief Western Society of Malacologists Annual Report, Vol. 36, p 65 description, comparison to related species, geographic distribution and number of lots in the LACM collection, which provides a measure of relative abundance. Incorporation of taxonomic advances - Most groups are subjected to major revision, bringing them into conformity with recent taxonomic advances. Some subgenera are raised to full genera to avoid the implication of ancestry implied by traditional usage. However, most monotypic genera are accepted. Treatment of new species - The format is sufficiently detailed to allow the descriptions and comparisons of approximately 350 new species to be included in the text of the books. Illustrations of radulae and details about paratypes will be provided in an appendix. Illustrations for the books — Shells are to be illustrated in black and white on a white background, close to the text and with full captions (see sample plate below). Most small specimens are illustrated by macrophotography, which often better conveys surface texture and color patterns than does the use of SEM for shell illustration. Sources of funding - Although there has long been a demand for the Eastern Pacific gastropod book, and its importance to resource managers and modem systematists is evident, there are no calls for proposals from NSF or other federal agencies for the preparation of taxonomic manuals. This lack of funding is counterproductive, given that an understanding of marine biodiversity is a national goal. Packard Foundation support - I am pleased to report that the David and Lucile Packard Foundation has provided me with funding for a part-time digital imaging and page-making technician. Michelle Schwengel is now preparing the images from my negatives taken over many years. Acknowledgments I am grateful to Daniel Geiger for encouragement and assistance in the early phases of preparation. Angel Valdes of the LACM is the technical support person, who will assist in editing and will prod me into finishing the books; Lindsey Groves of the LACM keeps up with cataloging and proofing. Michelle Schwengel is skillful with digital imaging; I thank her for the production of this poster. [Poster prepared July 2002] References Abbott, R. T. 1974. American Seashells, Second edition. The Marine Mollusca of the Atlantic and Pacific coasts of North America. New York: Van Nostrand Reinhold, 663 pp, 24 pis. Carpenter, P. P. 1857. Report on the present state of our knowledge with regard to the Mollusca of the west coast of North America. Report for the 26th meeting, British Association for the Advancement of Science, for 1856, pp. 159-368, pis. 6-9. Carpenter, P. P. 1 864. Supplementary report on the present state of our knowledge with regard to the Mollusca of the west coast of North America. Report British Association for the Advancement of Sciences, 1863, pp. 517-686. Western Society of Malacologists Annual Report, Vol. 36, p 66 Coan, E. V., Valentich-Scott, P., & Bernard, F. R. 2000. Bivalve seashells of western North America. Santa Barbara Museum of Natural History, Monographs, Number 2. Viii + 764 pp, 124 pis. Dali, W. H. 1921. Summary of the marine shellbearing mollusks of the northwest coast of America, from San Diego, California, to the Polar Sea, mostly contained in the collection of the United States National Museum, with illustrations of hitherto unfigured species. United States National Museum, Bulletin 1 12, 217 pp., 22 pis. Keen, A. M. 1971. Sea Shells of Tropical West America. 2nd Ed. Stanford, California, Stanford University Press. Xiv + 1,064 pp. Oldroyd, I. S. 1927. The marine shells of the west coast of North America. Stanford University Publications, University Series, Geological Sciences, vol. 2, part 1, pp. 1-298, pis. 1-29; part II, pp. 299-604, pis. 30-72; part III, pp. 605-941, pis. 73-108. Western Society of Malacologists Annual Report, Vol. 36, p 67 VII. REPORTS OF SOCIETY BUSINESS Executive Board Meetings, 6-10 June 2003 For a variety of logistical and other reasons, and extended discussions regarding finances and membership dues, the Executive Board Meeting was held over the course of several days, in various locations at the Natural History Museum of Los Angeles County. What follows is a summary of these meetings. Participating were: Hans Bertsch, Jorge Caceres, Douglas J. Eemisse, George L. Kennedy, Christopher Kitting, Edna Naranjo Garcia, Roger R. Seapy, Cynthia Trowbridge, and Angel Valdes. Old Business 1. Member payments. Lengthy discussions and multiple proposals regarding on-time or late payments, different categories or levels of membership, etc. The real problem is in members not paying their dues promptly, annually, or even less frequently. 2. Annual Report. In addition to the annual meeting, this is the major benefit of membership in the Society. It also provides a forum for the publication of Extended Abstracts — even encouraging submissions by student members. 3. Resignations and defining of position tasks. a. Importance of job role clarification. Of particular concern was overlapping and overwhelming tasks on individuals of roles that were appropriate to another position, for instance the Secretary, Treasurer, and Webmaster positions. Dr. Cynthia Trowbridge has served the society exceedingly well as appointed Treasurer, but as she explained, many of her tasks also involved Secretarial tasks. The Society congratulates her for service beyond what she had committed. b. Cynthia Trowbridge and Terry Arnold resigned their positions (respectively) as Treasurer and Secretary. New Business 1. Nominating Committee Report President: Jorge Caceres First Vice President: Peter Roopnarine (2005 meeting in San Francisco, CA) Second Vice President: Roland Anderson (2006 meeting in Seattle, WA, jointly with the American Malacological Society) Members-at-Large: George Kennedy and Edna Naranjo Garcia (chosen to repeat because of assistance they can provide for the 2004 meeting in Ensenada, Baja California, Mexico) Treasurer: Steve Lonhart Secretary: Hans Bertsch Webmasters: Doug Eemisse and Angel Valdes Editor of Annual Report: Doug Eemisse (with valuable assistance by Roger Seapy and other members of the board) Western Society of Malacologists Annual Report, Vol. 36, p 68 2. Treasurer’s Report. Emphasized the need for prompt payment of dues. Reserving conference sites often requires early monetary deposits to guarantee a discounted rate. The report was approved as presented. 3. President’s Report. Angel Valdes thanked Lindsey Groves for helping with the meeting, Kirstie Kaiser for her donation of $200 (U.S.) for the student grant fund, and Christopher Kitting for supplying $400 (U.S.) in funds from the Shore Institute of San Francisco. 4. Vice President’s Report. Jorge Caceres presented and discussed various aspects of the 24-28 June 2004 meeting, including logistics and symposia. He also suggested field/laboratory workshops prior to the meeting as a possible way to increase Society funds. Topics might include: Mollusc Diseases, and Molecular Tools in Malacology. Respectfully submitted, Hans Bertsch, Secretary Western Society of Malacologists Annual Report, Vol. 36, p 69 Annual Business Meeting The Annual Business Meeting of the Western Society of Malacologists was held in the Education Classroom of the Natural History Museum of Los Angeles County on 10 June 2003, beginning at 16:01 hours. 1. The President, Angel Valdes, again thanked Lindsey Groves, Kirstie Kaiser, and Christopher Kitting for their assistance and financial contributions. 2. The Treasurer’s Report emphasized the problem of collecting dues, and that members should pay in January/February, because conference costs are often due in March. 3. Memberships. Moved and seconded to raise annual dues: Regular: $20 (U.S.) Student: $8 (U.S.) If paid before [15 March] the fees would be reduced: Regular: $15 (U.S.) Student: $6 (U.S.) 4. The auction and reprint sale brought in about $720 (U.S.). 5. Nominating Committee. The slate of candidates presented in the minutes of the Executive Board Meeting was unanimously approved. 6. Student Grant Committee consisted of the following members: Lindsey Groves (Chair), Doug Eemisse, Daniel Geiger, Sandra Millen and Peter Roopnarine. Awards were presented to the following students: a. Diego Zelaya, Museo de la Plata, Departmento Zoologla Invertebrados, Buenos Aires, Argentina: “Species of Thyasira, Cyamiocardium, Cuspidaria, and Benthocardiella (Bivalvia) in the Magellanic and adjacent sub- Arctic waters.” ($800 U.S.) b. Matthew Clapham, Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA: “The ecological role of modem fauna mollusks in the late Paleozoic.” ($600 U.S.) c. Brooke Miller, Department of Ecology and Evolutionary Biology, University of California, Santa Cmz, CA, USA: “To chew or not to chew: a test of penis gnawing as an adaptive partner manipulating strategy in banana slugs (Ariolimax dolichophallus Mead).” ($450 U.S.) d. Alicia Hermosillo Gonzalez, Universidad de Guadalajara, Zapopan, Jalisco, Mexico: “Community ecology of the opisthobranch mollusks of Bahia de Banderas, Pacific coast of Mexico.” ($350 U.S.) 7. Best Paper Award: Marta Pola, Departamento de Biologia, Facultad de Ciencias del Mar y Ambientales, Universidad de Cadiz, Spain: “The systematics of Roboastra Bergh, 1877 (Nudibranchia, Polyceratidae, Nembrothinae).” Honorable Mention given to Shireen Fahey, California Academy of Sciences, San Francisco, CA, USA: “Phylogeny of Halgerda (Mollusca: Gastropoda) contrasting mitochondrial DNA (COI) and morphology.” 8. Incoming President Jorge Caceres gave a spectacular power point presentation on aspects, logistics, field trips, pre-conference workshops, etc., on the 24-28 June 2004 meeting of the Western Society of Malacologists in Ensenada, Baja California, Mexico. He emphasized not Western Society of Malacologists Annual Report, Vol. 36, p 70 only the scenic grandeur of the city and its locale, but the high caliber of molluscan research being conducted by various institutions. 9. At 17:10 the Transfer of Gavel from 2003 President Angel Valdes to 2004 President Jorge Caceres occurred, and with a welcome to Ensenada in June 2004, the 2003 meeting was adjourned. Respectfully submitted, Hans Bertsch, Secretary A Treasurer’s Report is not available- The Editor Western Society of Malacologists Annual Report, Vol. 36, p 71 Western Society of Malacologists Annual Report, Vol. 36, p 72 Western Society of Malacologists Annual Report, Vol. 36, p 73 Individual Memberships 2003 ADAMS, Mary Jane, 2116 Canyon Rd., Arcadia, CA 91006-1505 ALEJANDRINO, Alvin, 1905 E. 1st St. Apt. P, Long Beach, CA 90802 ALLEN, Mr. Jerry, 3750 Riviera Dr., Apt. 8, San Diego, CA 92109 ALLMON, Dr. Warren D., Paleontological Research Institute, 1259 Trumansburg Road, Ithaca , NY 14850 ANDERSON, Dr. Roland C., Seattle Aquarium, 1483 Alaska Way, Seattle, WA 98101 ANDERSON, Tamara, 1075 S. 2nd St., Lander, WY 82520 ANGEL OLIVAS, Jose, Institute de Sanidad Acuicola, A.C., Calle 9 y Gastelum 468 Local 14, Zona Cento, Ensenada, Baja California 22800, Mexico ARONOWSKY, Audrey, Dept. Integrative Biology, Univ. California, Berkeley, CA 94720 BALL, Ms. Minnie A., 5896 Ave. Juan Bautista, Riverside, CA 92509 BARTON, Bax R., P.O. Box 278, Seahurst, WA 98062 BERTSCH, Dr. Hans, 192 Imperial Beach Blvd, #A, Imperial Beach CA 91932 BOYER, Diana L., Dept. Earth Sciences - 036, Univ. California, Riverside, CA 92521 BRARY, Caren E., Hopkins Marine Station, Oceanview Boulevard, Pacific Grove, CA 93950 BURCH, Dr. Thomas A. and Beatrice L., 3599 Sylvan Pines Circle, Bremerton, WA 98310 CACERES MARTINEZ, Dr. Jorge. Institute de Sanidad Acuicola, A.C., Calle 9 y Gastelum 468 Local 14, Zona Cento, Ensenada, Baja California 22800, Mexico CAMACHO-GARCIA, Yolanda E., California Academy of Sciences, San Francisco, CA 94118 CAMPILLO, ORSO ANGULO, Departmento de Biologia Marina, Centro Interdisciplinario de Ciencias Marinas, Institute Politecnico Nacional, Av. I.P.N. s/n. Col. Playa Palo de Sta. Rita, C.P. 23096, A.P. 592, La Paz, Baja California Sur, Mexico CARLTON, Dr. James T., Maritime Studies Program, Mystic Seaport, Mystic, CT 06355 CARR, Dr. Walter E., 2043 Mohawk Dr., Pleasant Hill, CA 94523 CATE, Jean M. address unknown CHAN, Jamie M., 1201 44th Ave., Apt. 5, San Francisco, CA 94122 CHANEY, Barbara K., 1633 Posilipo Lane, Santa Barbara, CA 93108 CHANEY, Dr. Henry W., Museum of Natural History, 2559 Puesta del Sol Road, Santa Barbara, CA 93105 CLAPHAM, Matthew, Dept. Earth Sciences, , Univ. Southern Calif., Los Angeles, CA 90089-0740 CLARKE, Jordan Z., P.O. Box 6850, Fullerton, CA 92834-6850 CLAYTON, Julie, 2582 28th Ave. West, Seattle, WA 98199 COAN, Dr. Eugene V., 891 San Jude Ave., Palo Alto, CA 94306-2640 COCKBURN, Tom, 7683 Colin Place, Saanichton, BC, Canada V8M 1N6 CORDEIRO, Dr. James R, Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 USA COX, Erin, Dept. Biological Science, California State University, 800 N. State College Blvd., Fullerton, CA 92647 COWIE, Dr. Robert, Center for Conservation Research and Training, University of Hawaii, 3050 Maile Way, Gilmore 409, Honolulu, Hawaii 96822 CURIEL, Sergio, Instituto de Sanidad Acuicola, A.C., Calle 9 y Gastelum 468 Local 14, Zona Cento, Ensenada, Baja California 22800, Mexico D'ASARO, Dr. Charles N., Dept, of Biology, College of Science and Technology, 1 1000 University Parkway, Pensacola, FL 32514-5751 DAVIS, Cheryl L., 3306 Euclid Ave., Concord, CA 94519 DAYRAT, Dr. Benoit, Invertebrate Zoology and Geology, California Academy of Sciences, Golden Gate Park, San Francisco, CA 94118 DEMARTINI, Dr. John D., 1 1 1 1 Birch Ave., McKinleyville, CA 95519-7915 DOBRAN, Dr. John, P.O. Box 99923, Pacific Beach, CA. 92109-9998, USA DORNBO, Dr. Steve, Dept. Earth Sciences, Univ. So. Calif, Los Angeles, CA 90089-0740 EERNISSE, Dr. Douglas J., Dept, of Biological Science, California State Univ., Fullerton, CA 92834-6850 EMERSON, Dr. William K., 10 East End Ave., Apt. 18E, New York, NY 10021 FAHEY, Shireen, 170 Taringa Parade, Indooroopilly, Queensland 4068, Australia FAHY, Neil E., 1425 South Mayfair Ave., Daly City, CA 94015-3867 FENBERG, Phillip, Section Ecology, Behavior, & Evolution, UC San Diego, 9500 Gilman Dr., La Jolla, CA 92093- 0116 Western Society of Malacologists Annual Report, Vol. 36, p 74 FERGUSON, Ralph E., 617 North Fries Ave., Wilmington, CA 90744-5401 FLENTZ, John and Mary, 4541 Lambeth Court, Carlsbad, CA 92008-6407 FOWLER, Bruce H., 1074 Dempsey Rd., Milpitas, CA 95035 FRAISER, Margaret L., Dept. Earth Sciences, Univ. Southern Calif., Los Angeles, CA 90089-0740 FREST, Dr. Terrence J., 25 1 7 NE 65th St., Seattle WA 98 1 1 5-7 1 25 FRICK, Kinsey, Dept. Zoology, 46 College Road, Univ. New Hampshire, Durham, NH 03824 FUKUYAMA, Allan, 7019 157th SW, Edmonds, WA 98026 GELLER, Dr. Jonathan B., Moss Landing Marine Laboratories, Moss Landing, CA 95039 GHISELIN, Dr. Michael T., Dept. Invertebrate Zoology & Geology, California Academy of Sciences, San Francisco, CA 94118 GILBERTSON, Lance, Orange Coast College, P.O. Box 5005, Costa Mesa, CA 92628 GODDARD, Dr. Jeffery, Marine Science Institute, University of California, Santa Barbara, CA 93106 GOODWIN, Daniel R., Research Dept., Things Marine, P.O. Box 6432, Honolulu, HI 96818 GOODWIN, David, Dept. Geosciences, University of Arizona, Tucson, Arizona 85721 GOSLINER, Dr. Terry, California Academy of Sciences, San Francisco, CA 94118 GROVES, Lindsey T., Natural History Museum of L.A. County, 900 Exposition Blvd., Los Angeles, CA 90007 HARBO, Dr. Rick, Resource Management, Fisheries and Oceans Canada, South Coast, 3225 Stephenson Point Road, Nanaimo, B.C. V9T 1K3, Canada HAWKES, Elizabeth A., Dept, of Biological Sciences, California State Univ., Hayward, CA 94542-3083 HELLBERG, Dr. Michael E., Dept. Biological Sciences, 202 Life Sciences Bldg. Louisiana St. Univ., Baton Rouge, LA 70803 HERMOSILLO-GONZALES, Alicia, 4619 San Dario Ave., Box 138, Laredo, TX 78041 HERTZ, Carole and Jules, 3883 Mt. Blackburn Ave, San Diego, CA 92111 HICKMAN, Dr. Carole S., Dept, of Integrative Biology, University of California, Berkeley, CA 94720-3140 HOCHBERG, Dr. F.G., Museum of Natural History, 2559 Puesta del Sol Road, Santa Barbara, CA 93105 HOFFMAN, Juliet, 1680 Terrace Rd., Walnut Creek, CA 94596 HUTSELL, Linda & Kim, 5804 Lauretta St. # 2, San Diego, CA 92110 JACKSON, John D., Odyssey Publishing, 1 1558 Rolling Hills Dr., El Cajon, CA 92020 JOFFE, Anne, 1 163 Kittiwake Circle, Sanibel Island, FL 33957 JOHANNES, Mr. Edward J., 13717 Linden Ave. N, Apt. 108, Seattle, WA 98133-6952 JOHNSON, Rebecca, 1763 Chestnut Street, San Francisco, CA 94123 KAISER, Kirstie L., Paseo de las Conchas Chinas #115, Puerto Vallarta, Jalisco 48300, MEXICO KENNEDY, Dr. George L., Pacific Paleontological Consultants [or simply. Pacific Paleo], 8997 Moisan Way, La Mesa, California 91941,(619)667-1030 (with answering machine), (619) 462-8072 (fax) KITTING, Dr. Christopher L., Dept, of Biological Sciences, California State Univ., Hayward, CA 94542-3083 KNOWLTON, Dr. Ann L., Department of Biology, MS 9160, Western Washington University, 516 High Street, Bellingham, WA 98225-9160 KOCH, Wendy, 1215 West Seldon Lane, Phoenix, AZ 85021 KOOL, Dr. Silvard P., 14 Vale Lane, New Seabury, MA 02649 LANCE, James R., 746 Agate Street, San Diego, CA 92109 LANDYE, J. Jerry, 1433 Rockwood Dr., Alamogordo, NM 88310-3920 LEE, Jacquie, 1 175 Chapman St., Victoria, British Columbia, V8V 2T5, Canada LEONARD, Dr. Janet L., Joseph M. Long Marine Laboratory, University of Califomia-Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060 LINDBERG, Dr. David R., Dept. Integrative Biology & Museum of Paleontology, Univ. California, Berkeley, CA 94720 LONG, Steve, 914 Reese St., Oceanside, CA 92054-5231 LONHART, Dr. Steve, Monterey Bay National Marine Sanctuary, 299 Foam St., Monterey, CA 93940 LOUIE, Kristina D., Univ. California, Dept, of OBEE (Biology), 621 Charles E. Young Drive South, Los Angeles, CA 90095-1606 MARELLl, Dr. Dan C., Florida Dept, of Natural Resources, 100 8th Ave. SE, St. Petersburg, FL 33701-5095 McLEAN, Dr. James H., Natural History Musuem of Los Angeles County 900 Exposition Blvd, Los Angeles, CA 90007 METCALF, Dr. Artie L., Dept, of Biological Sciences, University of Texas, El Paso, TX 79968-0519 METZ, Dr. George and Roma, 121 Wild Horse Valley Dr., Novato, CA 94947 MEYER, Dr. Christopher P., Florida Museum of Natural History, Univ. Florida, Gainesville, FL 3261 1 Western Society of Malacologists Annual Report, Vol. 36, p 75 MIKKELSEN, Dr. Paula M., Department of Invertebrates, American Museum of Natural History, Central Park West at 79th St., New York NY 10024-5192 MILLEN, Dr. Sandra, Department of Zoology, The University of British Columbia, 6270 University Blvd., Vancouver, B.C., Canada V6T 1Z4 MILLER, Brooke, 395 Ano Nuevo Ave. #714, Sunnyvale, CA 94085 MILLER, Michael D., 4777 Ladner St., San Diego, CA 92113-3544 MONROE, Alice, 2468 Timbercrest Circle West, Clearwater, FL 33763-1626 MONTFORD, Nancy, Cove Corporation, 10200 Breeden, Road, Lusby, MD 20657 MOORE, Dr. Ellen J., 3324 SW Chintimini Ave., Corvallis, OR 97333-1529 MULLINER, David K. and Margaret, 5283 Vickie Dr., San Diego, CA 92109-1334 MURRAY, Dr. Harold D., 247 Pinewood Lane, San Antonio, TX 78216 NARANJO-GARCIA, Dr. Edna, Calle Estio No. 2, Mexico, D.F. 01600, Mexico NESBITT, Elizabeth A., Burke Museum of Natural History and Culture, Univ. Washington, Seattle, WA 98195- 3010 NOBUHARA, Takami, Science Education (Geology), Faculty of Education, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan NORRID, Charlotte C., 233 East Cairo Dr., Tempe, AZ 85282-3607 NYBAKKEN, Dr. James, Moss Landing Marine Laboratories, Moss Landing, CA 95039-0223 OSBORNE, Michael A., P.O. Box 929, Cannon Beach, OR 97110 PADIILA, Dr. Dianna, Dept. Ecology & Evolution, SUNY - Stony Brook, Stony Brook, NY 1 1794-5245 PEARCE, Dr. Timothy, Carnegie Museum of Natural History, 4400 Forbes Ave., Pittsburgh, PA 15213 PENNEY, Dr. Brian K., Dept. Biological Sciences, Univ. Alberta, Edmonton, Alberta T6G 2E9, Canada PERRONE, Antonio, via Palermo 7, 73014 Gallipoli, Italy PETIT, Richard E., 806 St. Charles Rd, North Myrtle Beach, SC 29582-2846 PITT, William D. and Lois, 2444 38th Ave., Sacramento, CA 95822 POWELL, Mr. Charles L. II, U.S. Geological Survey, MS 975, 345 Middlefield Rd., Menlo Park, CA 94025 RAINES, Bret K., P.O. Box 612, Victorville, CA 92393 RICE, Thomas C., P.O. Box 219, Port Gamble, WA 98364 ROOPNARINE, Peter D., Dept. Invertebrate Zoology & Geology, California Academy of Sciences, San Francisco, CA 94118-4599 ROTH, Dr. Barry, 745 Cole St., San Francisco, CA 94117 ROY, Dr. Kaustuv. Section of Ecology, Behavior & Evolution, Division of Biology, Univ. California, San Diego, La Jolla, CA 92093-0016 RUGH, Scott, Paleontology Dept., San Diego Natural History Museum, P.O. Box 121390, San Diego, CA 92112- 1390 RUNDELL, Rebecca J., University of Hawaii at Manoa, Dept, of Zoology, 2538 The Mall, HI 96822 RUSSELL, Dr. Michael, Biology Dept., 800 Lancaster Ave., Villanova University, Villanova PA 19085-1699 SAUL, Dr. Lou Ella, 14713 Cumpston St., Van Nuys, CA 9141 1 SCHROEDER, Walter D., 8101 La Palma Circle, Huntington Beach, CA 92646 SCOTT, Paul H. Valentich, Museum of Natural History, 2559 Puesta del Sol Road, Santa Barbara, CA 93105 SEAPY, Roger R., Dept, of Biological Science, California State University, Fullerton, CA 92834-6850 SHARPE, Saxon E., 6164 Chaise Ct., Reno NV 89509-7329 SKOGLUND, Carol, 3846 East Highland Ave., Phoenix AZ 85018-3620 SMITH, Dr. Judith Terry, 2330 14th St. North, #401, Arlington, VA 22201-5867 SMITH, Vic, California Academy of Sciences, San Francisco, CA 94118 SQUIRES, Dr. Richard L., Dept of Geological Sciences, California State University, 18111 Nordhoff St., Northridge, CA 91330-8266 STADUM, Carol J. 7563 Gibraltar St. #22, Carlsbad, CA 92009-7426 STANSBERY, Dr. David H., Museum of Zoology, Ohio State University , Columbus, OH 43210-1394 STEWART, Katherine, 19 La Rancheria, Carmel Valley, CA 93924 STURM, Dr. Charles F. Jr., 5024 Beech Road., Murrysville, PA 15668-9613 TANG, Carol, California Academy of Sciences, Golden Gate Park, San Francisco, CA 94118 TERRY, Matt, 1465 Popenoe Rd., La Habra Hts, CA TOMANEK, Dr. Lars, Hopkins Marine Station, Oceanview Boulevard, Pacific Grove, CA 93950 TROWBRIDGE, Dr. Cynthia D., Hatfield Marine Science Center, Newport, OR 97365 VALDES, Dr Angel, County Museum of Natural History, 900 Exposition Blvd, Los Angeles, CA 9007 Western Society of Malacologists Annual Report, Vol. 36, p 76 VALLES, Yvonne, California Academy of Sciences, Golden Gate Park, San Francisco, CA 94118 VAN ALSTYNE, Dr. Kathy, Shannon Point Marine Center, 1900 Shannon Point Road, Anacortes, WA 98221 VASQUEZ, Rebeca, Instituto de Sanidad Acuicola, A.C., Calle 9 y Gastelum 468 Local 14, Zona Cento, Ensenada, Baja California 22800, Mexico VELARDE, Ronald G., Marine Biology Lab, 4918 North Harbor Dr., Suite 101, San Diego, CA 92106 VENDRASCO, Michael, Dept, of Earth and Space Sciences, 595 Charles Young Drive, University of California, Los Angeles, CA 90095-1567 VERMEIJ, Dr. Geerat J., Dept. Geology, Univ. California, Davis, CA 95616 VOIGHT, Dr Janet, Dept, of Zoology, The Field Museum, 1400 S. Lake Shore Dr., Chicago, IL 60605-2496 WEBSTER, Sara, Dept, of Biological Sciences, California State Univ., Hayward, CA 94542-3083 WOOLSEY, Jody, 3717 Bagley Ave. #206, Los Angeles, CA 90034 WU, Dr. Shi-Kuei, 4175 Amber St., Boulder, CO 80304 YANCEY, Dr. Thomas E., Dept, of Geology, Texas A & M University, College Station, TX 77843-31 15 YOUNG, H. D. and Wilma G., 14550 Stone Avenue North, Seattle, WA 98133 ZACHERL, Dr. Danielle, Dept. OBEE, 621 Charles E. Young Drive South, Univ. California - Los Angeles, Los Angeles, CA 90095-1606 Institutional Memberships 2003 ABT. SCHRIFTENTAUSCH, Senckenberfische Naturforschende, Senckenberg-Anlage 25, D-6 Frankfurt A.M..1, Germany ACADEMY OF NATURAL SCIENCES, Serials Librarian, Nineteenth and Parkway, Philadelphia, PA 19103 ACQUISITION SECTION, Department of Library Services, The Natural History Museum, Cromwell Road, London SW7 5BD, England, UK AMERICAN CONCHOLOGIST, Treasurer: Phil Dietz, P.O. Box 151, Cape May, NJ 08204-0151 AMERICAN GEOLOGICAL INSTITUTE, The Library, 4220 King St., Alexandria , VA 22302 AMERICAN MALACOLOGICAL SOCIETY, do Susan B. Cook, 4201 Wilson Blvd., Suite 1 10-455, Arlington, VA 22203 BIBIOTECA, Inst, de Ciencias del Mar y Limnol, AP Postal 70-305 Cuidad Universit Ciudad Universitaria, Mexico, D.F. D-4150, Mexico BISHOP MUSEUM LIBRARY, 1525 Bernice St., FMLY PO Box 19000A, Honolulu, HI 96817-2704 BOEKHANDEL JUSTUS LIPSIUS BVBA, Belgicalaan 35, B-1080 Brussel, Belgium MOLLUSK LIBRARY, DELAWARE MUSEUM OF NATURAL HISTORY, P.O. Box 3937, Wilmington, DE 19807 DEPARTMENT OF MOLLUSKS, Museum of Comparative Zoology, 26 Oxford St., Cambridge, MA 02138 DR. H. K. MIENIS, PUBL. EDITOR, Israel Malacological Society, Kibbutz Netzer Sereni 70395, Israel EARTH SCIENCES INFORMATION CENTRE, 350-601 Booth St., Ottawa, Ontario KIA 0E8, Canada EXCHANGE AND GIFT DIVISION, Library of Congress, Washington, DC 20540 FIELD MUSEUM OF NATURAL HISTORY, Library-Subscriptions, Roosevelt Rd. at Lake Shore Dr., Chicago, IL 60605-2496 FISHERIES AND OCEANS LIBRARY, Pacific Biological Station, 3190 Hammond Bay Rd., Nanaimo, British Columbia, V9R 5K6, Canada FORSCHUNGSTELLE, Staatlishces Museum fiir Tierkunde, Augustusstrasse 2, 8010 Dresden, Germany FUNDACAO UNIV RIO GRANDE, Biblioteca, Av. Italia, Km 08, 96201-900 Rio Grande RS, Brazil HANCOCK LIBRARY OF BIOLOGY AND OCEANOLOGY, University of Southern California, Los Angeles, CA 90089-0371 HATFIELD MARINE SCIENCE CENTER, GUIN LIBRARY, OREGON STATE UNIVERSITY, 2030 Marine Science Drive, Newport, OR 97365 HOPKINS MARINE STATION, Miller Library, Oceanview Blvd., Pacific Grove CA 93950 HUMBOLDT-UNIVERSITAT ZU BERLIN, Universitatsbibliothek, ZB Museum fUr Naturkunde, TB Systematische Zoologie, InvalidenstralJe 43, D- 101 15 Berlin, GERMANY INSTITUT ROYAL DES NATURELLES DE BELGIQUE, Rue Vautier 31, 1040 Bruxelles, Belgium INSTITUTE OF GEOLOGICAL & NUCLEAR SCIENCES, Librarian, P.O. Box 30-368, Lower Hutt, New Zealand INSTITUTE OF GEOLOGY & PALEONTOLOGY, The Library, Faculty of Science, Tohoku University, Sendai, Japan INSTITUTO DI ZOOLOGIA DE UNIVERSITA, Societa Siciliana di Scienze Natur, Via Archirafi, 18, 90123 Western Society of Malacologists Annual Report, Vol. 36, p 77 Palermo, Italy LIBRARY FM-25, SERIALS DIVISION, UNIVERSITY OF WASHINGTON, Seattle, WA, 98195 LIBRARY SERIALS, UNIVERSITY OF HAWAII, 2550 The Mall, Honolulu, HI 96822 LIBRARY, CANADIAN MUSEUM OF NATURE, P. O. Box 3443, Station D, Ottawa, Ontario, KIP 6P4, Canada LIBRARY, MS-955, U.S. GEOLOGICAL SURVEY, 345 Middlefield Rd., Menlo Park, CA 94025 LIBRARY, SAN DIEGO MUSEUM OF NATURAL HISTORY, P.O. Box 1390, San Diego, CA 921 12 LITERATURE RESOURCES DEPARTMENT, BIOSCIENCE INFORMATION SERVICE, 2100 Arch St., Philadelphia, PA 19103 MAIN LIBRARY (SERIALS), UNIVERSITY OF CALIFORNIA, Berkeley, CA 94720 MALACOLOGICAL COMMITTEE, RUSSIAN ACADEMY OF SCIENCES, Universitetskaya Naberezhnaja 1, St. Petersburg B- 1 64 Russia MALACOLOGICAL SOCIETY OF CHINA, P.O. Box 34-35, Taipei, Taiwan MATRA MUSEUM, P.O. Box 103, H-3201 Gyongyos, Hungary MILLIKAN LIBRARY, ACQUISITIONS 1-32, CALIFORNIA INSTITUTE OF TECHNOLOGY, 1201 E. California Blvd., Pasadena CA 91109 MOLLUSK DIVISION, MUSEUM OF ZOOLOGY, UNIVERSITY OF MICHIGAN, Ann Arbor Ml, 48104 MUSEUM D’HISTOIRE NATURELLE, Bibliotheque, Case Postale #434, CH -121 1 Geneve 6, Switzerland MUSEUM NATIONAL D’HISTOIRE NATURELLE, Biologic Marins et Malacologie, 55 Rue de Buffon, 75005 Paris, France MUSEUM OF NEW ZEALAND, Te Papa Library, Library Manager, P.O. Box 467, Wellington, New Zealand NATIONAL MUSEUM OF SCOTLAND, The Library (Serials) , Chambers Street, Edinburgh, EHl IJF Scotland NATIONAL MUSEUM OF VICTORIA, 285-321 Russell Street, Melbourne, VIC 3000 Australia NETHERLANDS MALACOLOGICAL SOCIETY, do Zoological Museum, P.O. 94766, 090 GT Amsterdam, Netherlands NORTHERN CALIFORNIA MALACOLOZOOLOGICAL CLUB, c/o 121 Wild Horse Valley Dr., Novato CA 94947-3615 PACIFIC NORTHWEST SHELL CLUB, c/o Ann Smiley, 2405 NE 279th St., Richfield, WA 98642 RESEARCH LIBRARY, NATURAL HISTORY MUSEUM, 900 Exposition Blvd, Los Angeles, CA 90007 RUSSIAN ACADEMY OF SCIENCES, Paleontological Institute Library, Profsayuznaya uL, 1 13, Moscow 1 17321, Russia SANTA BARBARA MUSEUM OF NATURAL HISTORY, Library, 2559 Puesta del Sol Road, Santa Barbara, CA 93105 SERIALS UNIT, LIBRARY, AMERICAN MUSEUM OF NATURAL HISTORY, Central Park West at 79th St. , New York, NY 10024 SIO LIBRARY/SERIALS 0219, University of California San Diego, 9500 Gilman Drive, La Jolla CA 92093-0219 SOCIEDADE BRASILEIRA DE MALACOLOGIA, Instituto de Biosciencias-USP, CX.P. 1 1.461, Sao Paulo SP, Brazil SOUTH AUSTRALIAN MUSEUM , The Library , North Terrace, Adelaide 5000, SA, Australia THE LIBRARY, CALIFORNIA ACADEMY OF SCIENCES, Golden Gate Part, San Francisco CA 941 18 THE LIBRARY, DEPARTMENT OF ZOOLOGY, ARIZONA STATE UNIVERSITY, Tempe, AZ 85281 THE LIBRARY, FRIDAY HARBOR LABORATORY, Friday Harbor, WA 98250 THE LIBRARY, MARINE BIOLOGICAL LABORATORY, WOODS HOLE OCEANOGRAPHIC INSTITUTE, Woods Hole MA 02543 THE LIBRARY, MOSS LANDING MARINE LABORATORIES, Moss Landing CA 95039 THE LIBRARY, OHIO STATE MUSEUM, 1813 North High Street, Columbus OH 43210 THE LIBRARY, PALEONTOLOGICAL RESEARCH INSTITUTE, 1259 Trumansburg Road, Ithaca NY 14850 UCLA SCIENCE & ENGINEERING LIBRARY, 8251 Boelter HL/GEO, P.O. Box 951598, Los Angeles CA 90095-1598 UNIVERSITY OF WEST FLORIDA, Library Serials, 1 1000 University Parkway, Pensacola FL 32514 Western Society of Malacologists Annual Report, Vol. 36, p 78 THE WESTERN SOCIETY OF MALACOLOGISTS ANNUAL REPORT For 2004 Volume 37 Abstracts and Papers from the 37th Annual Meeting of the Western Society of Malacologists held in Ensenada, Mexico June 2007 JDAm cicese. Officers of the Western Society of Malacologists for 2004 President First Vice President Second Vice President Secretary Treasurer Members at Large Webmasters Jorge Caceres Peter Roopnarine Roland Anderson Hans Bertsch Steve Lonhart George Kennedy Edna Naranjo Garcia Doug Eemisse Angel Valdes Committees and Appointments Editorial Board Nora Foster (Editor) Hans Bertsch Rosa del Carmen Campay Western Society of Malacologists Annual Report Vol. 36, p. 2 TABLE OF CONTENTS Volume 37 I. ECOLOGY SESSION/ SESION ECOLOGI A Organized by/ Organizado por Todd Huspeni 1 0 What larval stages of digeneans can tell us about natural disturbances? (The cercariae of Cerithidea piculosa in Celestun, Yucatan before and after the Hurricane Isidore) ^Que nos pueden decir los estadios larvales de digeneos sobre las alteraciones naturales? (la cercaria de Cerithidea piculosa en Celestun, Yucatan antes y despues del Huracan Isidora) Ma. Leopoldina Aguirre Macedo, Ma. Trinidad Sosa Medina and Reyna Rodriguez Olay 10 Shifting baselines in the bivalve assemblage of Mission Bay, San Diego Cambios de los puntos de referenda moviles (shifting baseline) del agrupamiento de bivalvos de la Bahia Mision, San Diego Jeffrey Crooks 12 Reproductive cycle of sympatric mussels in Baja California, Mexico Ciclo reproductivo de especies de mejillon que coexisten en Baja California, Mexico Sergio Curiel Ramirez Gutierrez and Jorge Caceres Martinez 13 A comparison of the trematode parasites of Batillaria cumingi in native (Japan) versus introduced (California) populations Una comparacion del parasito trematodo de Batillaria cumingi en poblaciones nativas (Japon) versus introducidas (California) Eleca Dunham, Mark Torchin, Armand Kuris and Ryan F. Hechinger 14 Mass stranding of Argonauta spp. (Cephalopoda: Argonautidae) in Bahia de la Paz, Golfo de California, Mexico Varamientos masivos dQ Argonauta spp. (Cephalopoda: Argonautidae) en Bahia de la Paz, Golfo de California, Mexico Andres Gonzalez Peralta 1 5 Comparisons of mollusks and predatory fishes among restored and historical marshes, as evidence of environmental health versus predation pressure by fishes Comparaciones de moluscos y peces depredadores en los pantanos historicos y restaurados, como una evidencia del medioambiente saludable contra la presion de depredacion por peces Christopher L. Kitting and Cheryl L. Davis 16 Trematodes associated with mangrove habitat in Puerto Rican salt marshes Trematodos asociados con el habitat de manglares en marismas saladas de Puerto Rico Kevin D. Lafferty, Ryan F. Hechinger, Julio Lorda, and Luis Soler 17 Annual Report Vol.^^, p. 3 Western Society of Malacologists Using monitoring to study unpredictable, high impact events: effects of human collection of the intertidal limpet Lottia gigantea Uso de monitoreos para estudiar eventos impredecibles de alto impacto: Efectos de la recolecta de la lapa intermareal Lottia gigantea por el ser humano Raphael Sagarin, Richard Ambrose, Bonnie Becker, Jack Engle, Steve Murray, Peter Raimondi and Dan Richards 1 8 Preliminary morphometric-biogeographic analysis of the genus Quoyula (Gastropoda: Coralliophilidae) Analisis morfometrico-biogeografico preeliminar del genero Quoyula (Gastropoda: Coralliophilidae) Juan Carlos Solis Bautista, Eugenio Carpizo Ituarte and Antonio Trujillo Ortiz 20 Ecology of the introduced ribbed mussel (Geukensia demissa) in Estero de Punta Banda, Mexico: Interactions with the native cord grass, Spartina foliosa Ecologi'a del mejillon veteado {Geukensia demissa) introducido en el Estero de Punta Banda, Mexico: Interacciones con el pasto marino, Spartina foliosa Mark Torchin, Kevin D. Lafferty, Ryan F. Hechinger, Kathleen Whitney and Todd Huspeni 21 II. OPISTOBRANCH SESSION/ SESION OPISTOBRANQUIOS Organized by/ Organizado por Hans Bertsch 22 Taxonomic, ecological and zoogeographic revisions to Pacific Coast Nudibranchs (Behrens, 1991) Revisiones taxonomicas, ecologicas y zoogeograficas a Pacific Coast Nudibranchs (Behrens, 1991) David Behrens and Hans Bertsch 22 Opisthobranch fauna of Bahia de Banderas, Mexico (tropical eastern Pacific) Fauna de Opistobranquios de Bahia de Banderas, Mexico (Pacifico este tropical) Alicia Hermosillo 27 A new species of Marionia from the Indo-Pacific region (Mollusca: Nudibranchia) Una nueva especie de Marionia de la region del Indopaclfico (Mollusca: Nudibranchia) Victor G. Smith and Terrence M. Gosliner 28 Two new species of dorid nudibranchs (Mollusca, Opisthobranchia) from the Mar de Cortes, Baja California, Mexico Dos especies nuevas de nudibranquios doridos (Mollusca, Opisthobranchia) del Mar de Cortes, Baja California, Mexico Hans Bertsch and Angel Valdes 30 III. PHYLOGENETICS SESSION/ SESION FILOGENETICA Organized by/ Organizado por Douglas J. Eemisse 3 1 Revival of the genus Cyanoplax Pilsbry, 1892 for a clade of west coast chitons Reestablecimiento del genero Cyanoplax Pilsbry, 1 892 para un dado de quitones de la costa oeste Douglas J. Eemisse 3 1 Western Society of Malacologists Annual Report Vol. 36, p. 4 A new method for genome size estimation in Haliotis rufescens (Archaeogastropoda: Haliotidae) using dapi-fluorescence fading Un nuevo metodo para la estimacion del tamano genomico en Haliotis rufescens (Archaeogastropoda: Haliotidae) mediante desvanecimiento dapi-fluorescente Cristian Gallardo Escarate, Josue Alvarez Borrego and Miguel Angel del Rio Portilla 33 Phylogeography and diversity of the eastern Pacific coast Filogeografia y diversidad de la costa Pacifico del este David Jacobs, Todd Haney and Kristina Louie 35 Morphometric analysis of Chione cortezi and C. fluctifraga (Bivalvia: Veneridae) of Gulf of California, Mexico Analisis morfometrico de Chione cortezi y C. fluctifraga (Bivalvia: Veneridae) del Golfo de California, Mexico Ana Livia Licona Chavez, Francisco Correa Sandoval and Faustino Camarena 35 Genetic characterization of some populations of Chione californiensis and C subimbricata (Bivalvia: Veneridae) in the Gulf of California and Pacific coast of Mexico Caracterizacion genetica de algunas poblaciones de Chione californiensis y C. subimbricata (Bivalvia:Veneridae) en el Golfo de California y el Pacifico Mexicano Ana Livia LiconaChavez, Francisco Correa Sandoval 1 y Jorge de la Rosa 37 DNA sequence test of the lined chiton (Tonicella) species complex Prueba de secuenciacion de ADN para el complejo de especies de Quiton Rayado Tonicella) Reuben L. Paul and Douglas J. Eemisse 39 IV. AQUACULTURE SESSION /SESION ACUACULTURA Organized by/ Organizado por Carmen Guadalupe Paniagua Chavez 40 The rainbow lip pearl oyster Pteria sterna cultured in Bahia de La Paz: Tradition and modernity Cultivo de concha nacar Pteria sterna en la Bahia de la Paz: Tradicion y modemidad Carlos Caceres Martinez and Jorge Chavez Villalba 40 Evaluation of growth rate of Lyropecten {Nodipecten) subnodosus cultured in three different temperatures and fed with three bi-algal diets Evaluacion del crecimiento de Lyropecten {Nodipecten) subnodosus cultivada en tres diferentes temperaturas y alimentada con tres dietas bialgales Nallely A. Ceron Ortiz, Beatriz Cordero Esquivel, Cecilia Flores Vergara, Patricia Asencio Padilla and Miguel Robles Mungaray 42 Daily growth of early stages of sympatric mussels as criteria to differentiate colonization strategy Crecimiento diario de estadios tempranos de mejillones coexistentes para diferenciar su estrategia de colonizacion Sergio Curiel Ramirez Gutierrez and Jorge Caceres Martinez 43 Western Society of Malacologists Annual Report Vol. 36, p. 5 Settlement of mytilids and its importance to mussel culture in Baja California, Mexico Fijacion de mitilidos y su importancia para el cultivo de mejillon en Baja California, Mexico Sergio Curiel Ramirez Gutierrez and Jorge Caceres Martinez 44 Genetic advancements on cultured abalone in Baja California Avances en la genetica del abulon cultivado en Baja California Miguel Angel del Rio Portilla, Marisela Aguilar Juarez, Cristian Gallardo Escarate, Miroslava Vivanco Aranda and Ana Livia Licona Chavez 46 Growth and gametogenic cycle of the palmate oyster, Saccostrea palmula (Bivalvia: Ostreidae), in El Conchalito Estuary Desarrollo y ciclo gametogenico del ostion palmeado, Saccostrea palmula (Bivalvia: Ostreidae), en el Estero El Conchalito Esteban F. Felix Pico, Oscar E. Holguin Quinonez and Federico A. Garcia Domingue 46 Aquaculture of abalone Haliotis spp. in Isla de Cedros, Baja California, Mexico Acuicultura del abul6n Haliotis spp. en Isla de Cedros, Baja California, Mexico Jose Guadalupe Gonzalez Aviles 50 Preliminary studies on the cryopreservation of red abalone {Haliotis rufescens) larvae Estudios preeliminares sobre la criopreservacion de larvas de abulon rojo {Haliotis rufescens) Jessica Guadalupe Roman Espinoza and Carmen Guadalupe Paniagua Chavez 51 Culture of juvenile red abalones, Haliotis rufescens, in a recirculating water system Cultivo de juveniles de abulon rojo, Haliotis rufescens, en un sistema de recirculacidn Miroslava Vivanco Aranda and Miguel Angel del Rio Portilla 53 V. GENERAL SESSION/ SESION GENERAL Organized by/ Organizado por Miguel Angel del Rio Portilla 54 Macrobenthonic molluscan thanatocoenoses in the Colorado River Delta area as a reflection of ecological changes Tanatocenosis de moluscos macrobentonicos en el area del Delta del Rio Colorado como un reflejo de cambios ecol6gicos Guillermo E. Avila Serrano, Karl W. Flessa and Miguel Agustin Tellez Duarte 54 What happened to the bearded horse mussel at Bahia de los Angeles? (some after thoughts and possible microorganism identification) ^Que ocurrid al mejilldn caballo barbado en Bahia de los Angeles? (algunas reflexiones posteriores y posible identificacion de microorganismos) Wesley M. Farmer 55 Notes on the knowledge of the freshwater mollusks of Mexico Notas sobre el conocimiento de los moluscos de agua dulce de Mexico Edna Naranjo Garcia 56 Western Society of Malacologists Annual Report Vol. 36, p. 6 Paleontology and geochronology of Pleistocene marine terrace faunas, Punta Banda, northwestern Baja California Paleontologia y geocronologia de la fauna de terrazas marinas del Pleistoceno en Punta Banda, noroeste de Baja California George L. Kennedy, Thomas K. Rockwell, Francisco Suarez Vidal, Daniel R. Muhs and John F. Wehmiller 58 Lipid composition and fatty acid profile related to spawning cycle of the queen conch Strombus gigas (Linnaeus) from the National Park of Arrecife de Alacranes, Yucatan Determinacion de la composicion de lipidos y obtencion del perfil de acidos grasos con relacion al ciclo de desove en el caracol marino Strombus gigas (Linnaeus) en el Parque Nacional de Arrecife de Alacranes, Yucatan Luis Alfonso Rodriguez Gil and Ake Canul S. Santos 59 Molluscan taphonomy and paleoecology at Mesa San Carlos, Baja California, Mexico Tafonomia y paleoecologia de Moluscos en la Mesa, San Carlos, Baja California, Mexico Miguel Agustin Tellez Duarte and Javier Helenes Escamilla 61 Genetic structure of the red octopus Octopus maya in the coasts of Yucatan Estructura genetica del pulpo Octopus maya en las costas de Yucatan Jorge A. Tello Cetina, Jose B. Escamilla Sanchez and Andres M. G6ngora Gomez 62 On the diet of two octopod species found at California cold seep ecosystems Dieta de dos especies de pulpo encontradas en ecosistemas de surgencia de agua fria en California Kent D. Trego 63 Abyssal mollusk notes Kent D. Trego 64 Herpes-like virus associated with eroded gills of the Japanese oyster Crassostrea gigas adults in Mexico Virus tipo Herpes asociado con la erosion branquial en adultos del osti6n Japones Crassostrea gigas en Mexico Rebeca Vasquez Yeomans, Jorge Caceres Martinez and Antonio Figueras Huerta 65 Identification isolated bacteria from gills of the Japanese oyster Crassostrea gigas cultured in Bahia Falsa, B. C., Mexico during a mortality episode Identificacion de bacterias aisladas de las branquias del ostion Japones Crassostrea gigas cultivado en Bahia Falsa, Baja California, Mexico durante un episodio de mortalidad Rebeca Vasquez Yeomans, Adrian Mauricio Garcia Ortega and Jorge Caceres Martinez 66 VI. POSTER SESSION SESION CARTELES Organized by/ Organizado por Beatriz Cordero Esquivel 67 Western Society of Malacologists Annual Report Vol. 36, p. 7 Parasitic diagnosis of the eastern oyster Crassostrea virginica of Gulf of Mexico Diagnostico parasitologico del ostion Crassostrea virginica del Golfo de Mexico Ma. Leopoldina Aguirre Macedo, Raul Sima Alvarez, Karla Roman Magana y Jorge Giiemez Ricalde 67 Genetic analysis of populations of the abalone (Haliotis spp.) using RAPD’s Analisis genetico de poblaciones de abulon {Haliotis spp.) mediante el uso de RAPD’s Marisela Aguilar Juarez and Miguel Angel del Rio Portilla 68 Preliminary results in reproductive effort of Atrina maura in Laguna de San Ignacio BCS, Mexico Resultados preeliminares sobre el esfuerzo reproductivo de Atrina maura en Laguna de San Ignacio Baja California Sur, Mexico Daniela Barrios Ruiz and Carlos Caceres Martinez 69 Histopathological analysis of the native oyster Ostrea conchaphila (= O. lurida) in relation to mortality episodes of Japanese oyster Crassostrea gigas from Bahia Falsa, Baja California, Mexico Analisis histopatologico del ostion nativo Ostrea conchaphila {=0. lurida) en relacion con los episodios de mortalidad del ostion Japones Crassostrea gigas de Bahia Falsa, Baja California, Mexico Jorge Caceres Martinez, Yanet Guerrero Renteria, Rebeca Vasquez Yeomans, Sergio Curiel Ramirez Gutierrez and Patricia Macias Montes de Oca 70 Parasitological and histopathological analysis of the ribbed mussel Geukensia {=lschadium) demissa, from Estero de Punta Banda, Baja California, Mexico Analisis parasitologico e histopatologico del mejillon Geukensia (= Ischadium) demissa, del Estero de Punta Banda, Baja California, Mexico Jorge Caceres Martinez, Jose Soledad Ibarra Rivera and Yanet Guerrero Renteria 71 Terrestrial gastropods of south Nuevo Leon, Mexico Gastropodos terrestres del sur de Nuevo Leon, Mexico Alfonso Correa Sandoval and Maria del Carmen Salazar Rodriguez 73 Distribution of “G” bands in the karyotype of Pomacea patula catemacensis Distribucion de bandas “G” en el cariotipo de Pomacea patula catemacensis Maria Esther Diupotex Chong, B. L. Montejo Quintero and M. Uribe Alcocer 73 Molecular characterization of Vibrio harveyi and its pathogenicity to postlarval Mytilus californianus Caracterizacion molecular de Vibrio harveyi y su patogenicidad hacia larvas de Mytilus californianus Galdy Hernandez Zarate, Jorge Zamora Castro and Jorge Olmos Soto 74 Western Society of Malacologists Annual Report Vol. 36, p. 8 Allometric analysis of juveniles of the red abalone, Haliotis rufescens, in a recirculating aquaculture system Analisis alometrico de juveniles de abulon, Haliotis rufescens, en un sistema de recirculacion Marcela Enid Niinez Martinez, Jacob Alberto Valdivieso Ojeda and Miguel Angel del Rio Portilla 76 Molluscs in coastal lagoons of Sonora and Sinaloa, Mexico: Habitat and habits Moluscos de las lagunas costeras de Sonora y Sinaloa, Mexico: Habitat y habitos Martha Reguero Meza 77 Prevalence of the parasite Sabinella shaskyi (Gastropod: Eulimidae), and sublethal damage in Eucidaris galapagensis (Echinoidea) in the Galapagos Islands, Ecuador Prevalencia del parasito, Sabinella sharskyi (Gasteropodo: Eulimidae) y dano subletal en Eucidaris galapagensis (Echinoidea) en las Islas Galapagos, Ecuador J. I. Sonnenholzner, L. B. Ladah and K. D. Lafferty 78 Thermoregulatory study in pink abalone Haliotis corrugata Estudio de termoregulacion en abul6n rosa Haliotis corrugata Ana Denisse Re Araujo, Carlos Gerardo Re Araujo, Fernando Diaz Herrera and E. Zarina Medina Romo 8 1 Community variations and growth of mollusks in modem carbonate environments along a latitudinal transect in the Gulf of California, Mexico Variaciones de la comunidad y desarrollo de moluscos en ambientes modemos de carbonato a lo largo de un transecto latitudinal en el Golfo de California, Mexico Arturo Tripp Quezada 82 Mollusk community associated with the coral Pocillopora in Tenacatita, Jalisco, Mexico Comunidad de moluscos asociados al coral Pocillopora en Tenacatita, Jalisco, Mexico Cinthya Velarde Nuno, Luis Eduardo Calderon Aguilera, Dora Wauman and Ernesto Lopez Uriarte 83 Use of microsatellite loci to evaluate the genetic variability in cultured juveniles of the Japanese oyster Crassostrea gigas Uso de microsatelites para evaluar la variablidad genetica de juveniles de ostion Japones Crassostrea gigas de cultivo Jacob Alberto Valdivieso Ojeda, Zaul Garda Esquivel and Miguel Angel del Rio Portilla 85 Taxonomic key for the identification of benthic opistobranchs in Mexican reefs Claves taxonomicas para la identificacion de opistobranquios en arrecifes Mexicano Andrea Zamora Silva and Martha Reguero Meza 86 VII. REPORTS OF SOCIETY BUSINESS 87 Western Society of Malacologists Annual Report Vol. 36, p. 9 I. ECOLOGY SESSION SESION ECOLOGI A Organized by/ Organizado por Todd Huspeni University of California, Santa Barbara, USA. What larval stages of digeneans can tell us about natural disturbances? (The cercariae of Cerithidea piculosa in Celestun, Yucatan before and after the Hurricane Isidore) Ma. Leopoldina Aguirre Macedo, Ma. Trinidad Sosa Medina and Reyna Rodriguez Olay Centro de Investigacion y de Estudios Avanzados del IPN Unidad Merida. Km. 6 Antigua Carretera a Progreso. A.P. 73, Cordemex, Merida, Yucatan, C.P. 97310 Mexico E-mail: leo@mda.cinvestav.mx In February 2001, we started a long-term program to study the larval digenean parasites of the horn snail Cerithidea piculosa around a water spring in Celestun, Yucatan. In September 2002, Hurricane Isidore hit the Yucatan Peninsula with devastating effects. There are few studies in the literature determining the effect of density-independent factors such as hurricanes upon communities, especially those of parasites or their hosts. Therefore, the aim of this paper was to describe the changes in the snail population density, prevalence, species composition and community structure of the larval stages of digeneans of the horn snail before and after this natural disturbance. Snail population density (snails/m ), temperature and salinity were recorded monthly from February 2001 to April 2004. Collected snails were transported to the laboratory, measured and dissected to find larval stages of digeneans. The taxonomic identity and prevalence was determined for each digenean species. The maximum number of snails/m before the hurricane was 23 ± 4 in November 2001; the lowest value was 3 ± 1 in September 2002. Five species of digeneans in the cercarial stage were found infecting the snail population: Renicola sp. A (prevalence range 1-35), Heterophydae gen. sp. (1-26), Mesostephanus appendiculatoides (2- 6), Renicola sp. B (4-34) and Euhaplorchis californiensis (3). The number of species per month was between 1 and 4 before the hurricane. In all cases where snails were infected no double or triple infections were found suggesting that interspecific interactions and predation were processes structuring this parasite community. Immediately after the hurricane, the snail population disappeared until February 2003 with 0.8 ± 1 snails/m^. Since then, densities have been increasing slowly to reach 14 ± 7 snails/m^. However, infected snails did not show up until December 2003. In this month, up to 144 snails (1.3%) were infected with the heterophyd cercariae and in April 2004 at least 4 of the 5 digenean species mentioned above have been recorded with prevalences between 1 and 5%. In any case, a double or triple infection has been found, suggesting that interspecific interactions and predation were influencing the parasite community structure. In summary, after the hurricane, the snail population disappeared for 5 months and the digeneans for 1 year and 4 months. However, once they appeared, the same structuring forces seem to be acting upon these parasite communities. Western Society of Malacologists Annual Report Vol. 36, p. 10 ^Que nos pueden decir los estadios larvales de digeneos sobre las alteraciones naturales? (la cercaria de Cerithidea piculosa en Celestun, Yucatan antes y despues del Huracan Isidora) A partir de febrero del 2001, iniciamos un programa de largo plazo para estudiar los estadios larvales de parasitos digeneos del caracol cuemo Cerithidea piculosa alrededor de un cuerpo de agua en Celestun, Yucatan. En septiembre del 2002 el huracan Isidora azoto la Peninsula de Yucatan con efectos devastadores. Hay pocos estudios en la literatura que determinan el efecto de factores denso-independientes como los huracanes, sobre las comunidades, especialmente de parasitos o de sus hospederos. Por consiguiente, el objetivo de este trabajo fue describir tanto los cambios en la densidad de la poblacion de caracol cuemo, como la prevalencia, composicion de especies y estmctura de la comunidad de los estadios larvales de sus parasitos digeneos antes y despues del impacto del huracan Isidora. Entre febrero del 2001 y abril del 2004 se registro mensualmente la densidad poblacional del caracol (caracoles/m ), asi como la temperatura y la salinidad. Los caracoles recolectados fueron transportados al laboratorio, donde se midieron y se disectaron para buscar fases larvales de digeneos. Se calculo la identidad taxonomica y 'y prevalencia para cada especie de digeneo. El niimero maximo de caracoles/m antes del huracan fue de 23 ± 4 en noviembre del 2001, el valor mas bajo fue de 3 ± 1 en septiembre del 2002. Se encontraron 5 especies de digeneos en la fase de cercaria infectando a la poblacion del caracol: Renicola sp. A (con un rango de prevalencia de 1-35), Heterophydae gen. sp. (1-26), Mesostephanus appendiculatoides (2-6), Renicola sp. B (4-34) y Euhaplorchis californiensis (3). Antes del huracan el numero de especies por mes estaba entre 1 y 4. En todos los casos de caracoles infectados no hubo infecciones dobles o triples, sugiriendo que las interacciones interespecificas y de depredacion fueron procesos que estructuraron a la comunidad de este parasito. Inmediatamente despues del huracan, la poblacion del caracol desaparecio hasta febrero del 2003 cuando se encontrd 0.8 ± 1 caracoEm^. Desde entonces, las densidades comenzaron a incrementarse paulatinamente hasta alcanzar 14 ± 7 caracoles/m . Sin embargo, los caracoles infectados no se observaron hasta dicembre del 2003. En este mes, hasta 144 caracoles (1.3%) se infectaron con cercarias de heterophydos y durante abril del 2004 por lo menos 4 de las 5 especies de digeneos mencionados anteriormente se han registrado con una prevalencia entre 1 y 5%. En todo caso, se han encontrado infecciones dobles o triples, sugiriendo que las interacciones interespecificas y la depredacidn influenciaron en la estmctura de la comunidad del parasito. En resumen, despues del huracan, la poblacion del caracol desaparecid por 5 meses y la de digeneos por 1 ano y 4 meses. Sin embargo, una vez que ellos aparecieron, las mismas flierzas estmcturales parecen estar actuando sobre las comunidades del parasito. Western Society of Malacologists Annual Report Vol. 36, p. 1 1 Shifting baselines in the bivalve assemblage of Mission Bay, San Diego Jeffrey Crooks Tijuana River National Estuarine Research Reserve, 301 Caspian Way, Imperial Beach, CA 91932 USA E-mail: jacrooks@yahoo.com Although humans have been impacting local ecosystems for millennia, it is only recently that the most dramatic changes have occurred. While this in itself is not particularly unexpected, what is surprising is the degree to which we fail to account for these past changes. This forgetfulness leads to reduced expectations of what to expect from our natural systems - a phenomenon which has been called the shifting baseline syndrome. This issue of shifting baselines was addressed in San Diego’s Mission Bay, which represents one of the most highly modified marine ecosystems on the entire coastline. Starting in the mid- 1800’s, the bay has seen river diversions, dredging, filling, sand amendments, wetlands destruction, over-harvesting, and pollution. This has resulted in substantial shifts in the system’s resident plant and animal communities. This is made evident by examining mollusk populations, for which there is a relatively good source of historical information. Over the last 125 years, the bivalves in the bay have been characterized by a loss of large organisms, changing species assemblages that reflect altered habitat characteristics, and invasion by exotics. Overall, the bivalve community now present in the bay is markedly different from that which existed just 100 years ago, and this will tend to bias our view of “natural” conditions. Such patterns emphasize the need to consider historical conditions and shifting baselines in our efforts to understand, conserve, and restore these valuable last slices of nature in the urban sea. Cambios de los puntos de referenda moviles (shifting baseline) del agrupamiento de bivalves de la Bahia Mision, San Diego Aunque los humanos han impactado los ecosistemas locales durante milenios, los cambios mas dramaticos han ocurrido recientemente. Aunque esto es muy comiin, lo sorprendente es el grado en que nosotros no consideramos estos cambios. Este olvido tiende a reducir las expectativas de lo que esperamos de nuestros sistemas naturales - un fenomeno que se ha llamado el sindrome del cambio de los puntos de referenda moviles (shifting baseline syndrome). Este problema del cambio de los puntos de referenda fue percibido en la Bahia Mision de San Diego, la cual representa uno de los ecosistemas marines altamente modificados en todo el litoral. A partir de 1 800, la bahia comenzo a ser testigo de los cambios ocurridos en el rio, tales como, cambios de direccion, dragados, rellenos, cambios en el tipo de arena, destruccion de los pantanos, sobre explotacion de especies y contaminacion. Esto ha producido cambios sustanciales en las comunidades de plantas y animales que residen en el sistema. Esto es evidente cuando se revisan las poblaciones de moluscos para las cuales hay una fuente relativamente buena de informacion historica. Durante los ultimos 125 anos, los bivalves en la bahia se han caracterizado por presentar una perdida de organismos de mayor tamano, cambios en las agrupaciones de las especies que reflejan caracteristicas de habitats alterados e invasion por especies exoticas. En conjunto, la comunidad de bivalvos ahora presente en la bahia es notablemente diferente a la que existio hace 100 anos, y esto tendera a desviar nuestra vision de lo que son las condiciones Western Society of Malacologists Annual Report Vol. 36, p. 12 "naturales". Tales patrones enfatizan la necesidad de considerar las condiciones historicas y los cambios de los puntos de referenda en un esfuerzo por entender, conservar y restaurar estos ultimos y valiosos recursos de la naturaleza inmersos ahora en un oceano urbano. Reproductive cycle of sympatric mussels in Baja California, Mexico Sergio Curiel Ramirez Gutierrez and Jorge Caceres Martinez Laboratorio de Biologia y Patologia de Organismos Acuaticos Departamento de AcuiculturanCentro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada. A.P. 2732. Ensenada, Baja California, C.P. 22860 Mexico E- mail: scuriel@cicese.mx The bay mussel Mytilus galloprovincialis and the California mussel Mytilus californianus are sympatric species in the Pacific coast of Baja California, northwest Mexico. To determine the reproductive cycle of both species in a coexistence area, a study of quantitative stereology was performed from January to December 1995. Adults of M. californianus and M. galloprovincialis were collected from Mina del Fraile (exposed rocky shore) and adults of M. galloprovincialis were collected in a culture area (protected area). In both species, spawning organisms were found all year round. The population of M galloprovincialis had one major reproductive season from autumn to early spring in both sites. In late autumn, gonad follicles were full of ripe gametes and developing gametes and some spawning may have occurred. However, the peak of the spawning occurred in early winter. Minor spawning was more frequent in M galloprovincialis from the culture area than from the Mina del Fraile. These differences may be associated with the more stable environmental conditions in the culture area, which also could influence differences in percentage of storage cells from spring to summer. The reproductive season for M californianus lasts from winter to summer. From winter to early summer, gonad follicles were full of ripe gametes and developing gametes and some spawning may have occurred. The reproductive strategy of M. californianus is based on an extended reproductive season from winter to summer, while the reproductive season of M. galloprovincialis goes from autumn to early spring. Ciclo reproductive de especies de mejillon que coexisten en Baja California, Mexico El mejillon azul Mytilus galloprovincialis y el mejillon de California Mytilus californianus coexisten en la costa del PaciTico de Baja California, Mexico. Para determiner el ciclo reproductivo de ambas especies en una zona de coexistencia, se realize un estudio de esterologia cuantitativa, entre enero y diciembre de 1995. Mensualmente se recolectaron 30 ejemplares adultos de M. californianus y M. galloprovincialis en la Mina del Fraile (costa rocosa expuesta) y 30 adultos de M. galloprovincialis en una zona de cultivo (area protegida). En ambas especies se encontraron ejemplares en condicion reproductiva a lo largo de todo el ano. Sin embargo, a nivel poblacional, M. galloprovincialis mostro un periodo reproductivo de inviemo a inicios de primavera tanto en la costa rocosa como en la zona de cultivo. A finales de otono los foliculos gonadicos estuvieron llenos de gametos maduros y de gametos en desarrollo y se detectarona algunos desoves. Sin embargo, el desove masivo ocurrio a inicios del inviemo. La condicion reproductiva fue mas frecuente en M. galloprovincialis del area de cultivo que en M. Western Society of Malacologists Annual Report Vol. 36, p. 13 gal/oprovincialis de la zona rocosa. Esas diferencias pueden estar asociadas con las condiciones ambientales, que parecen ser mas estables en la zona de cultivo, mismas que tambien ayudan a explicar las diferencias en el porcentaje de celulas de almacenamiento durante la primavera y verano. For el otro lado, los desoves masivos de M. califomianus ocurrieron en diciembre y de junio a septiembre. A comparison of the trematode parasites of Batillaria cumingi in native (Japan) versus introduced (California) populations 12] I Eleca Dunham , Mark Torchin , Armand Kuris and Ryan F. Hechinger 'University of California, Santa Barbara. Santa Barbara, CA 93106. USA E-mail: e_dunham@lifesci.ucsb.edu ^National Center for Ecological Analysis and Synthesis, UCSB 735 State Street, Suite 300, Santa Barbara, CA 93101-3351 USA Invasive species can often alter community structure and stability. Japanese oyster mariculture introduced Batillaria cumingi to California. In California salt marshes where B. cumingi has successfully invaded, the native horn snail {Cerithidea californica) has become less abundant and it has been extirpated in one estuary. The replacement of C. californica by B. cumingi has also altered the trematode communities in the salt marsh ecosystem. C. californica harbors up to 18 different trematode species and is becoming displaced by B. cumingi which hosts only 1 nonnative trematode species (Cercaria batillariae). These changes led us to investigate the trematode fauna that uses B. cumingi as a 1st intermediate host in its native habitat in Japan. Examination of B. cumingi populations revealed a positive correlation between prevalence (proportion of infected snails) and latitude (p<0.05). Trematode species richness also increases with latitude. These data will be further analyzed and discussed in the context of habitat quality, snail abundance, and the presence of other Batillaria and Cerithidea species in Japan. Una comparacion del parasito trematodo de Batillaria cumingi en poblaciones nativas (Japon) versus introducidas (California) Las especies invasivas pueden alterar frecuentemente la estructura y estabilidad de la comunidad. Con la maricultura del ostion japones se introdujo a Batillaria cumingi en California. En las marismas saladas de California donde B. cumingi se ha establecido satisfactoriamente, especies nativas como el caracol cuemo {Cerithidea californica) ha disminuido en abundancia y ha sido erradicado de un solo estero. El reemplazamiento de C. californica por B. cumingi tambien ha alterado las comunidades de trematodos en los ecosistemas de marismas saladas. C. californica hospeda a mas de 1 8 diferentes especies de trematodos y estan siendo desplazados por B. cumingi, el cual hospeda solo 1 especie de trematodo no nativo (Cercaria batillariae). Estos cambios permitieron investigar la fauna de trematodos que utiliza B. cumingi como un ler hospedero intermediario en su habitat nativo en Japon. La revision de poblaciones de B. cumingi revelaron una correlacion positiva entre la prevalencia (proporcion de caracoles infectados) y la latitud (p>0.05). La riqueza de especies de trematodos tambien se incrementa con la latitud. Western Society of Malacologists Annual Report Vol. 36, p. 14 Estos datos podrian ademas ser analizados y discutidos en el contexto de calidad del habitat, abundancia de caracoles y la presencia de otras especies de Batillaria y Cerithidea en Japon. Mass stranding oi Argonauta spp. (Cephalopoda: Argonautidae) in Bahia de la Paz, Golfo de California, Mexico Andres Gonzalez Peralta Universidad Autonoma de Baja California Sur Carretera al Sur Km. 5.5, A.P. 19-B, La Paz, Baja California Sur, C.P. 23080 Mexico E-mail: aperalta98@prodigy.net.mx Species of the genus Argonauta Linnaeus, 1758 are widespread in tropical areas of the world oceans, but most of the available biological information about them consists of isolated records of their presence in specific localities. This paper describes the mass stranding of 3 species of Argonauta (A. cornuta, A. nouryi and A. pacifica) that takes place every year in winter and early spring at Bahia de La Paz, Gulf of California, Mexico (24° N). Data are presented on measurements of 1 136 shells of the 3 species that were collected in 1998, 1999, 2000 and 2001. That year, Argonauta shells were found at 14 localities in the bay, and at a variety of sites from 23° to 25° N on the east and west shores of the gulf Shells of A. cornuta were the most abundant, whereas the shells of A. pacifica were the largest. Annual stranding in the southern Gulf of California are assumed to occur when individuals ascend to the surface to reproduce, are transported to the coast by the wind and water movement, and finally are washed up on beaches at low tide. Varamientos masivos At Argonauta spp. (Cephalopoda: Argonautidae) en Bahia de la Paz, Golfo de California, Mexico Aunque las especies del genero Argonauta Linnaeus, 1758 estan ampliamente distribuidas en las areas tropicales de los oceanos del mundo, la mayoria de la informacibn biolbgica disponible sobre ellos consiste de registros aislados de su presencia en localidades especificas. Este trabajo describe varamientos masivos de 3 especies de Argonauta (A. cornuta, A. nouryi. y A. pacifica.), que tienen lugar todos los anos en inviemo y a principios de la primavera en Bahia de La Paz, Golfo de California, Mexico (24° N). Los datos estan presentados sobre las mediciones de 1136 conchas de las 3 especies que fueron recolectadas en 1998, 1999, 2000 y 2001. En esos anos, se encontraron las conchas de Argonauta en 14 localidades en la bahia y en una variedad de sitios, desde 23° a 25° N en las costas del este y oeste del Golfo. Las conchas de A. cornuta fueron las mas abundantes, mientras que las conchas de A. pacifica fueron las mas grandes. Se asume que los varamientos anuales en el sur del Golfo de California ocurren cuando los individuos ascienden a la superficie para reproducirse, estos son transportados a la costa por los vientos y el movimiento del agua y finalmente son depositadas en las playas durante la marea baja. Western Society of Malacologists Annual Report Vol. 36, p. 15 Comparisons of mollusks and predatory fishes among restored and historical marshes, as evidence of environmental health versus predation pressure by fishes Christopher L. Kitting and Cheryl L. Davis Department of Biological Sciences and Shore Laboratory California State University, Hayward, CA 94542 USA E-mail: chris.kitting@csueastbay.edu Our long-term comparisons of aquatic animals in replicate restored and historical brackish marshes in northern San Francisco Estuary uncovered large, persistent differences among populations found at different marsh sites. Comparisons of abundances of hypothetically major predators (fishes) and the most common benthic prey (often mollusks) among sites may indicate a negative association (as possible prey depletion) or a positive association, as possible indicators of suitable environments for diverse kinds of animals. Maximum gastropod mollusk densities were 100-100,000 hydrobiid snails per m , and maximum bivalve densities were -30 Macoma balthica and Corbicula fluminea per m . These high gastropod densities corresponded to moderate densities of fish mostly mosquitofish, Gambusia affmis and voracious gobies, Tridentiger spp. Minimum mollusk densities corresponded to minimum fish densities. Maximum fish densities, including native stickleback and sculpins, corresponded to moderate mollusk densities. Among sites, mollusk and fish abundances were positively correlated overall. Additional common animals, including major crustaceans, also were positively correlated with mollusks. Thus, we see no evidence that major fishes are detectably cropping mollusks or other major invertebrates in these marshes, but instead each group of animals is positively correlated among different marshes, each dense assemblage associated with marsh tidal pools on tidal channels and apparently, benthic algae. Transplantings in field bioassays can test for mechanisms accounting for the paucity of virtually all aquatic organisms from marshes without marsh tidal pools along channels. Comparaciones de moluscos y peces depredadores en los pantanos historicos y restaurados, como una evidencia del medioambiente saludable contra la presion de depredacion por peces Repetidas comparaciones a largo plazo de animales acuaticos en pantanos restaurados e historicos al norte del Estero de San Francisco mostraron diferencias importantes, entre las poblaciones encontradas en los diferentes sitios del pantano. Las comparaciones entre las abundancias de depredadores hipoteticos importantes (peces) con las presas bentonicas mas comunes (frecuentemente moluscos) entre diferentes sitios, pueden indicar una asociacion negativa (como posiblemente un agotamiento de la presa) o una asociacion positiva, como un posible indicador de ambientes adecuados para diversos tipos de animales. Las densidades maximas de moluscos gasteropodos fiieron de 100-100,000 caracoles hidrobiidos por m^, y las densidades maximas de bivalvos fueron -30 de Macoma balthica y de Corbicula fluminea por m^. Estas altas densidades de gasteropodos correspondieron a densidades moderadas de peces, principalmente el pez mosquito, Gambusia affmis y los voraces gobidos, Tridentiger spp. Las Western Society of Malacologists Annual Report Vol. 36, p. 16 densidades mi'nimas de moluscos correspondieron a densidades minimas de peces Las maximas densidades de peces, incluidos los natives “pez espinoso” y el “cavilat”, correspondieron a densidades moderadas de moluscos. Entre sitios, las abundancias de moluscos y peces fueron correlacionadas positivamente. Otros animales comunes, incluidos los crustaceos, tambien estuvieron positivamente correlacionados con los moluscos. For lo tanto, no obtuvimos evidencia de que los peces mas importantes consumieran moluscos u otros invertebrados en estos pantanos; sin embargo, cada grupo de animales esta positivamente correlacionado entre los diferentes pantanos, cada agrupacion esta asociada con pozas de marea sobre los canales y al parecer, con algas bentonicas. Los bioensayos de trasplante en el campo, pueden evaluar los mecanismos que contribuyen a dar como resultado la escasez de practicamente todos los organismos acuaticos en marismas sin posas de mareas a lo largo de los canales. Trematodes associated with mangrove habitat in Puerto Rican salt marshes Kevin D. Lafferty ’ , Ryan F. Hechinger Julio Lorda ’ and Luis Soler 'Western Ecological Research Center, United States Geological Survey 7801 Folsom Blvd., Suite 101, Sacramento, CA 95826 USA E-mail: lafferty@lifesci.ucsb.edu ^Marine Science Institute, University of California, Santa Barbara Santa Barbara, C A 93 1 06 USA Snails are commonly infected by trematode parasites. Trematodes can strongly impact the ecological and evolutionary dynamics of snail populations, since they castrate and increase mortality in snail hosts. The distribution of infection by parasites can greatly vary from place to place due to environmental and biological factors. Previous studies have suggested that prevalence of trematode infections on snails should be the highest in habitats that support many final hosts, which are the sources of parasite stages that infect snails. However, some studies have not found this relationship to be very strong. In this paper, we present data that suggest the prevalence of trematodes that parasitize Batillaria minima (Prosobranchia: Batillariidae), a common snail in Puerto Rico’s shallow coastal lagoons, is related to the distribution of mangroves, which serve as roosting areas for birds. We compared the prevalence of trematode infections on B. minima in two different habitats (mudflats vs. mangroves) in two lagoons of Puerto Rico and found a positive relation between the number of infections and mangrove coverage. Trematodos asociados con el habitat de manglares en marismas saladas de Puerto Rico Los caracoles son comiinmente infectados por parasitos trematodos. Los trematodos pueden impactar fiiertemente a la dinamica ecologica y evolutiva de las poblaciones de caracoles, ya que ellos limitan las poblaciones e incrementan la mortalidad de los caracoles hospederos. La distribucion de la infeccion por parasitos puede variar grandemente de un sitio a otro debido a factores biologicos y ambientales. Estudios previos han sugerido que la prevalencia de infecciones por trematodos sobre los caracoles pudiera ser mas alta en habitats donde se presentan muchos hospederos finales, los cuales son la fuente de estadios de parasitos que infectan caracoles. Sin embargo, algunos estudios no han encontrado que estar relacion sea tan estrecha. En este trabajo presentamos datos que sugieren que la prevalencia de trematodos que Western Society of Malacologists Annual Report Vol. 36, p. 17 parasitan a Batillaria minima (Prosobranchia: Batillariidae), un caracol comun en las lagunas costeras de Puerto Rico, se relaciona con la distribucion de manglares, los cuales sirven como areas de descanso para aves. Comparamos la prevalencia de infecciones de trematodos sobre B. minima en dos diferentes habitats, marismas contra manglares en dos lagunas de Puerto Rico y encontramos una relacion positiva entre el numero de infecciones y la cobertura del manglar. Using monitoring to study unpredictable, high impact events: effects of human collection of the intertidal limpet Lottia gigantea Raphael Sagarin', Richard Ambrose', Bonnie Becker^, Jack Engle^, Steve Murray'', Peter Raimondi^ and Dan Richards^ 'University of California, Los Angeles 405 Hilgard Avenue. P.O. Box 951361. Los Angeles, CA 90095- 1361 USA, E-mail: sagarin@ucla.edu 2 Cabrillo National Monument Foundation 1 800 Cabrillo Memorial Drive, San Diego, CA 92106 USA ^University of California, Santa Barbara, Santa Barbara, CA 93106 USA "California State University, Fullerton P.O. Box 34080, Fullerton, CA 92834-9480 USA ^University of California, Santa Cmz, 1 156 High Street, Santa Cruz, CA 95064 USA ^Channel Islands National Park, 1901 Spinnaker Drive, Ventura, CA 93001 USA Several regionally based multi-investigator coastal research programs have been developed in the last two decades to address large-scale issues such as fisheries management strategies and responses of communities to climate change, and to establish baseline data in case of a large scale perturbation such as an oil spill. These observational schemes may also be useful, when used in a comparative manner, to address localized issues such as the effects of human foraging activities on coastal populations. The Multi-Agency Rocky Intertidal Network (MARINe) is a consortium of 23 state, federal, university and private organizations that conducts intertidal community monitoring biannually at 34 mainland sites and 23 island sites in 6 different counties in Southern California. These sites include legally protected and enforced areas as well as sites with unlimited public access. We use data from 28 MARINe sites to compare the size structure of populations of the intertidal owl limpet Lottia gigantea. We find a clear and significant relationship between the median limpet size and the degree of protection from poachers afforded by the sites, with unprotected sites near population centers showing the lowest median size with few large individuals, and protected sites on the Channel Islands showing the largest median size with individuals from all size classes well represented (Fig. 1). Other hypotheses to explain the differences in size structure were rejected. No latitudinal pattern was found in size structure, nor was size structure related to the presence of predatory black oystercatchers {Haemotopus bachmanii). Examination of well-protected sites that allow visitation by large school and tourist groups revealed that these sites are rich with large limpets, providing further evidence that surreptitious poaching, rather than visitation to tide pools per se, is driving the trend toward smaller size structures. Elimination of large individuals from the population leads to a cascade of events that reduces reproductive output and would possibly depress population densities if not for the contribution of larvae from well protected reserve sites. Western Society of Malacologists Annual Report Vol. 36, p. 18 1 2 W . 1 Figure 1 Size frequency histograms for all observations of Lottia gigantea between Fall 1996 and Fall 2001 in four accessibility Categories. Category 1; sites where extensive collection is likely because access is not restricted by physical (e.g., gates), geological (e.g., steep cliffs) or enforced legal barriers (e.g., law enforcement patrols, gated communities), and the site is close to densely populated areas. Category 2; sites without enforced collection or visitation restrictions that are nonetheless expected to have lower levels of collection due to difficulty of access or distance from population centers. Category 3: sites with little to no expected collection due to well enforced access and/or collection restrictions and/or extreme difficulty of access. Category 4: sites on the Channel Islands which feature low resident human populations, and in many cases, enforced restrictions against collection and/or extreme difficulty of access. Uso de monitoreos para estudiar eventos impredecibles de alto impacto: Efectos de la recolecta de la lapa intermareal Lottia gigantea por el ser humano En las ultimas dos decadas se han realizado programas interdisciplinarios de investigacion costera para atender temas de impacto a gran escala tales como las respuestas de las comunidades al cambio climatico, estrategias en el manejo de las pesquerias y para establecer bases de datos como referenda en casos de alteraciones de gran escala como derrames petroleros. Tales esquemas de observacion tambien pueden ser utiles, cuando se usan en terminos comparativos, para atender a temas locales tales como los efectos de la recolecta de poblaciones costeras. La Agenda Multiple Rocky Intertidal Network (MARINe) es un consorcio de 23 organizaciones estatales, federates, universitarias y privadas que realizan monitoreos bianuales de la comunidad intermareal en 34 localidades costeras y 23 islas, en 6 condados del Western Society of Malacologists Annual Report Vol. 36, p. 19 sur de California. Estas localidades incluyen zonas legalmente protegidas asi como puntos de acceso publico ilimitado. Utilizamos los datos de 28 sitios registrados en el MARlNe y comparamos el tamano y la estructura de las poblaciones de la lapa intermareal Lottia gigantea. Encontramos correlaciones significativas entre la talla promedio de las lapas con los sitios monitoreados. Las lapas de menor tamano promedio se encuentran en sitios no protegidos y cercanos a centros poblacionales. En estos sitios se encontraron pocos ejemplares de tallas grandes. For otro lado, en los sitios protegidos como las Islas Channel, se encontro que el tamano promedio de las lapas es mayor y estan bien representadas todas las clases de talla. Preliminary morphometric-biogeographic analysis of the genus Quoyula (Gastropoda: Coralliophilidae) Juan Carlos Solis Bautista , Eugenio Carpizo Ituarte and Antonio Trujillo Ortiz*" ’ Institute de Investigaciones Oceanologicas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada, A.P. 453, Ensenada, B. C., C.P. 22860 Mexico E-mail: solisjcb@hotmail.com ■Facultad de Ciencias Marinas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada, A.P. 453, Ensenada, B. C., C.P. 22860 Mexico With the purpose of looking for possible biogeogaphic and morphometric variation, we investigated the morphology of two species of Quoyula: Q. monodonta and Q. madreporarum. We sampled these two species on coral populations in Punta Arena de la Ventana, Baja California Sur (Gulf) and Bahia de Huatulco, Oaxaca (Oaxaca), Mexico. We measured four features of each snail: total length, length of the first spiral, and length and width of the operculum. Specimens were taken by diving, and were removed from corals of the family Pocilloporidae. The proportion of Quoyula species in each coral community sampled was highly significant within the locality, being greater for Q. monodonta. In reference to the proportion between localities, Q. monodonta was significantly greater in the Gulf. In both the Gulf and Oaxaca, there is a clear morphometric separation between the two species. Quoyula madreporarum was significant bigger (P < 0.05) and more variable (P < 0.05) in the Gulf. The results may be considered as initial evidence of the possibility of two distinct species. Morphometric studies, with a greater number of variables, and molecular studies are needed to elucidate if the morphometric variation has a genetic base. Analisis morfometrico-biogeografico preeliminar del genero Quoyula (Gastropoda: Coralliophilidae) Con el proposito de buscar posibles variaciones biogeograficas y morfometricas, investigamos la morfologia de dos especies de Quoyula: Q. monodonta y Q. madreporarum. Muestreamos a estas dos especies sobre poblaciones de coral en Punta Arena de la Ventana, Baja California Sur (Golfo) y Bahia de Huatulco, Oaxaca, Mexico. Medimos cuatro caracteristicas de cada caracol: longitud total, longitud del primer espiral y longitud y ancho del operculo. Los especimenes fueron recolectados por buceo y fueron removidos de los corales de la familia Pocilloporidae. La proporcion de especies de Quoyula en cada comunidad de coral muestreado fue altamente significativa dentro de la localidad, siendo mas grande para Q. monodonta. En referenda a la Western Society of Malacologists Annual Report Vol. 36, p. 20 proporcion entre localidades, Q. monodonta fue significativamente mas grande en el Golfo. En ambas zonas estudiadas, el Golfo y Oaxaca, hay una clara separacion morfometrica entre las dos especies. Quoloya madreporarum se presento significativamente (P<0.05) mas grande y mas variable en el Golfo. Los resultados pueden ser considerados como evidencia inicial de la posibilidad de que se trata de dos especies distintas. Son necesarios mas estudios morfometricos con un mayor numero de variables y estudios moleculares, para elucidar si la variacion morfometrica inicialmente detectada tiene una base genetica. Ecology of the introduced ribbed mussel {Geukensia demissa) in Estero de Punta Banda, Mexico: Interactions with the native cord grass, Spartina foliosa Mark Torchin', Kevin D. Lafferty^, Ryan F. Hechinger’, Kathleen Whitney’ and Todd Huspeni’ 'Marine Science Institute, University of California, Santa Barbara Santa Barbara, CA 93106 USA, E-mail: torchin@lifesci.ucsb.edu ^Western Ecological Research Center, United States Geological Survey, 7801 Folsom Blvd., Suite 101, Sacramento, CA 95826 USA Introduced populations of Guekensia demissa occur on the West Coast of North America. They have been reported in San Francisco Bay, four Southern California wetlands, and in Estero de Punta Banda (EPB), Baja California, Mexico. We randomly sampled benthic invertebrates in four habitat types within EPB: marsh, channel, mudflat and pan. Geukensia demissa was the most abundant bivalve in the wetland at EPB. It was significantly associated with the native cordgrass, Spartina foliosa, and occurred at higher average densities in vegetated marsh sites (24/ m ) and 5par/ma-dominated tidal channels (35/ m ), compared to mudflat (0/ m ), and pan (0/ m ) sites. We estimated that the total biomass of this invader was over four times that of the next most abundant bivalve, Tagelus sp. in EPB. We examined G. demissa for parasites and found that only a few native parasites colonized this introduced host at very low prevalences and intensities. We performed bird surveys to determine the habitat overlap and potential impact of this mussel on the EPB population of light-footed clapper rails {Rallus longirostriis levipes), an endangered species in the United States. The high abundance of G. demissa in EPB, its presence in clapper rail habitat, and its known effects on salt marsh habitat in its native range, warrant further investigations of the impact of this invader in EPB and elsewhere. Ecologi'a del mejillon veteado {Geukensia demissa) introducido en el Estero de Punta Banda, Mexico: Interacciones con el pasto marino, Spartina foliosa En la Costa oeste de America del Norte, se han establecido poblaciones del mejillon exotico veteado Geukensia demissa. Estas se han encontrado en la Bahia de San Francisco, en cuatro zonas pantanosas del sur de California, EUA y en el Estero de Punta Banda (EPB), Baja California, Mexico. Como resultado de un estudio de invertebrados bentonicos realizado en cuatro habitats dentro del EPB (pantano, canales, marisma y pozas), encontramos que el bivalvo mas abundante file Geukensia demissa. Su presencia fue asociada (p > 0.05) con el pasto marino nativo, Spartina foliosa. Las densidades promedio mas altas se registraron en los canales donde domina S. foliosa (35/m ) y en sitios pantanosos con vegetacion (24/m ). No se encontraron en Western Society of Malacologists Annual Report Vol. 36, p. 21 2 • 2 marisma (0/m ) ni en pozas (0/m ). Estimamos que la biomasa total de este invasor fue cuatro voces mayor que Tagelus sp., el segundo bivalvo mas abundante en el EPB. Analizamos a G. demissa para detectar la presencia de parasitos y encontramos que solo algunos parasitos nativos, con muy baja prevalencia e intensidad, colonizaron a este hospedero. Realizamos un registro de aves para determinar la sobreposicion de habitat y el impacto potencial de este mejillon sobre la poblacion del ave de marisma, Rallus longirostrus levipes, una especie en peligro de extincion en los Estados Unidos. La alta abundancia de G. demissa en el EPB y sus efectos conocidos en las marismas, garantizan futuras investigaciones del impacto de este invasor en el EPB y en otras localidades donde se ha establecido. II. OPISTOBRANCH SESSION SESION OPISTOBRANQUIOS Organized by/ Organizado por Hans Bertsch California Academy of Sciences, San Francisco Taxonomic, ecological and zoogeographic revisions to Pacific Coast Nudibranchs (Behrens, 1991) I 2 David Behrens and Hans Bertsch California Academy of Sciences, San Francisco' 5091 Debbie Court, Gig Harbor, WA 98335 USA, E- mail: dwbehrens@comcast.net ^192 Imperial Beach Blvd., #A, Imperial Beach, CA 91932 USA, E-mail: hansmarvida@sbcglobal.net The second edition of Pacific Coast Nudibranchs (Behrens, 1991) summarized the taxonomic and biological information on 217 species of opisthobranch molluscs found within the geographic range of the book, from Alaska to Baja California. Since its printing almost 15 years ago, many new species have been discovered and named, the ranges of known species have been expanded, additional ecological and morphological data have been published, and numerous taxonomic changes at the generic level have occurred. This is a short summary of Behrens, 2004, which updates these data and information. The complete text can be accessed at the following web sites: http://www.seaslugforum.net/display. and: http://slugsite.us/behrens/dave2004.pdf The opisthobranch fauna of the Pacific coast of the Americas, from the Alaskan Bering Strait to Baja California’s tip at Cabo San Lucas (hence including records from three countries: United States, Canada, and Mexico), now totals 252 species. Some of the species that were not in the 1991 book include the shelled cephalaspideans Cylichna diegensis, Acteocina eximia, Retusa zystrum, Volvulella californica, Volvulella panamica, Philine aperta, Bathydoris aioca, Diaulula greeleyi and others. Bathydoris aioca was originally described from northeast of Isla Guadalupe, Baja California, based on a single specimen collected in 1960. James Lance published a short manuscript in 1967 reporting the finding of this holotype specimen. Valdes and Bertsch (2000) reported on a series of specimens collected off the Oregon coast, from 1963-1965, providing further Western Society of Malacologists Annual Report Vol. 36, p. 22 anatomical descriptions of this deep water species (it is known from about 2700-2850 meters depth), as well as a significant range extension. The Nayarit, Mexico, species Peltocioris nayarita Ortea & Llera, 1981, is a synonym of Diau/u/a greeleyi (MacFarland, 1905), originally named from Brazil. The second half of Behrens, 2004, is titled “New Information and Nomenclatural Changes.” It includes range extensions, ecological data, and generic changes. For instance, the southern California species Navanax inermis has now been reported from Bolinas Lagoon in Marin County, northern California. The southernmost range of Berthella californica had previously been from the Islas Coronados, right next to the U.S./Mexican border. Its range is now extended to the Islas Galapagos. The range of Aegires albopunctatus is extended north from British Columbia to Ketchikan, Alaska. Polycera tricolor is reported from Ketchikan, Alaska; previously its northernmost occurrence had been in British Columbia. Tritonia myrakeenae, originally known from Santa Barbara, California, to Isla Cedros, Baja California, has since been reported from Costa Rica. Babakina festiva had been known from Marin County, California, to Nayarit, Mexico, along our coastline. It was also originally reported from Japan, and has since been reported as possibly occurring in Spain and New Zealand. Another range extension reported is its collection from the Bahamas, in the western Atlantic. The so-called “yellow-gilled porostome” Doriopsilla gemela has a distinctive, nearly flattened egg mass with large lecithotrophic eggs, rather than the typical upright circular ribbon with small eggs laid by other members of its genus and most other dorids. The life history and ecology of Doriopsilla gemela in Bahia de los Angeles were reported by Bertsch (2002), based on over 10 years of study in that Sea of Cortez location. The species almost always occurs on the pink sponge Pseudosuberites pseudos and the yellow sponge Cliona celata. It has a definite annual cycle, with the new generation appearing in the early fall. Some of the many generic changes that Behrens, 2004, reports include the following: Hopkinsia rosacea is now in the genus Okenia. Laila cockerelli has been transferred to the genus Limacia which holds priority by date of publication. Tambja fusca is the junior synonym of Tambja abdere, by reason of page priority. Anisodoris nobilis has been transferred to the genus Peltodoris based on anatomical data examined and described by Valdes (2002). There are a number of Panamic (tropical west America) province species that have now been reported from southern California. The outer coast of Baja California between Bahia Magdalena and Punta Eugenia is a provincial-level ecotonal transition region (Bertsch, 1993). Southern tropical species are well expected to occur within this region, as are northern temperate species. But for the tropical species to extend farther north is a definite exception (as the reverse also holds). Behrens (2004) reports that the following truly tropical Panamic species have been reported to occur in southern California waters: Tritonia pickensi, Flabellina bertschi, Polycera alabe, Chromodoris galexornm and Aplysia parvula. It is probably important to contrast the frequency and timing of their occurrences in the tropical Panamic province waters with those occurrences in the temperate southern California provincial waters. Seasonality and timing associated with El Nino events will then be quite obvious. So these may not really be “range extensions,” but most likely climatically influenced Western Society of Malacologists Annual Report Vol. 36, p. 23 periodic northerly distributions. These data are important to our understanding of marine biodiversity. A concluding comment which is very important to our understanding of the distribution and life histories of marine invertebrates: When we talk about the range or distribution of an organism, we should not just say it occurs from south point X to north point Y. We need to explain clearly where the majority of the specimens have been found. We need to discuss why species from one zoogeographic province are found in another. Currents move many larvae, but given water temperature variations, these may not survive. But at certain times, they do, and we have a range extension of a tropical species into the cooler temperate waters. Precise data are needed to really understand the biodiversity and biogeography of marine animals. For example, nearly every specimen of bird is reported to an international data base, so their seasonality, rareness, or “exceptions” (you know, the bird everyone flies thousands of miles to see or photograph, because it has never before been seen in Texas), are well noted. Every year, the Audubon Society sponsors a “bird count.” We need a similar effort for marine invertebrates. Definitely there are enough scuba divers who love nudibranchs that this could be a real possibility. Maybe even twice-a-year surveys — to try to understand some of the seasonal variation. [Note added during Annual Report publication preparation (2007): Three recent books (Behrens & Hermosillo, 2005, Camacho-Garci'a, Gosliner & Valdes, 2005, and Hermosillo, Behrens & Rios Jara, 2006; see review and discussion by Bertsch, 2007) incorporate and update these changes.] Literature Cited Behrens, David W. 1991. Pacific Coast Nudibranchs (second edition): A Guide to the Opisthobranchs, Alaska to Baja California. Sea Challengers, Monterey, CA. vi + 107 pp. Behrens, David W. 2004. Pacific coast nudibranchs, supplement II. New species to the Pacific coast and new information on the oldies. Proceedings California Academy of Sciences 55 (2): 11-54. Behrens, David W., and Alicia Hermosillo. 2005. Eastern Pacific Nudibranchs: A Guide to the Opisthobranchs from Alaska to Central America. Sea Challengers, Monterey, CA. vi + 137 pp. Bertsch, Hans. 1993. Opistobranquios (Mollusca) de la costa occidental de Mexico. In: S.I. Salazar-Vallejo & N.E. Gonzalez (eds.), Biodiversidad Marina y Costera de Mexico. Comission Nacional de Biodiversidad y CIQRO, Mexico, pp. 253-270. Bertsch, Hans. 2002. The natural history of Doriopsilla gemela Gosliner, Schafer, and Millen, 1999 (Opisthobranchia: Nudibranchia), at Bahia de los Angeles, Baja California, Mexico. Annual Report, Western Society of Malacologists 33: 7-8. Bertsch, Hans. 2007. Book news: review of two guides to western Mexican and Central American opisthobranchs, with biogeographic and supra-familial taxonomic comments. The Festivus 39 (1): 7-10. Western Society of Malacologists Annual Report Vol. 36, p. 24 Camacho-Garcia, Yolanda, Terrence M. Gosliner, and Angel Valdes. 2005. Guia de Campo de las Babosas Marinas del PaciTico Este Tropical / Field Guide to the Sea Slugs of the Tropical Eastern Pacific. California Academy of Sciences, SF. 129 pp. Hermosillo, Alicia, David W. Behrens & Eduardo Rios Jara. 2006. Opistobranquios de Mexico: Guia de Babosas Marinas del Pacifico, Golfo de California y las Islas Oceanicas. CONABIO and Universidad de Guadalajara, Mexico. 143 pp. Valdes, Angel. 2002. A phylogenetic analysis and systematic revision of the cryptobranch dorids (Mollusca, Nudibranchia, Anthobrancia). Zoological Journal of the Linnean Society 136: 535-636. Valdes, Angel, and Hans Bertsch. 2000. Redescription and range extension of Bathydohs aioca Marcus & Marcus, 1962 (Nudibranchia: Gnathodoridoidea). The Veliger 43 (2): 172-178. Revisiones taxonomicas, ecologicas y zoogeograficas a Pacific Coast Nudibranchs (Behrens, 1991) La segunda edicion de Pacific Coast Nudibranchs (Behrens, 1991) reunia informacion taxonomica y biologica de 217 especies de moluscos opistobranquios dentro del rango geografico del libro, desde Alaska hasta Baja California. Desde su impresion hace 1 5 anos, se han descubierto y nombrado muchas especies nuevas, se han ampliado los rangos de especies conocidas, se han publicado datos morfoldgicos y ecologicos adicionales y ha habido numerosos cambios taxonomicos a nivel genero. Este es un breve sumario de Behrens, 2004, que actualiza dicha informacion y datos. El texto completo se puede encontrar en los siguientes sitios web: http://www.seaslugforum.net/display.cfm?base=brbehrel&id= 12698 http://slugsite.us/behrens/dave2004.pdf Ahora son 252 especies en la fauna opistobranquia de la costa Pacifico Americano, desde el estrecho de Bering en Alaska, hasta la punta de Baja California en Cabo San Lucas (que incluye registros de tres paises: Estados Unidos, Canada y Mexico). Algunas de las especies que no incluia el libro de 1991 son los cefalaspideos con concha Cylichna diegensis, Acteocina eximia, Retusa zystrum, Volvulella californica, Volvulella panamica, Philine aperta, Bathydoris aioca, Diaulula greeleyi y otros. Bathydoris aioca fue descrita originalmente del noreste de Isla Guadalupe, Baja California, con base en un solo especimen colectado en 1960. James Lance publico un breve manuscrito en 1967 en que reporta el hallazgo de este especimen holotipico. Valdes y Bertsch (2000) reportaron sobre una serie de especimenes colectados en la costa de Oregon entre 1963 y 1965, y proporcionan descripciones anatdmicas adicionales sobre esta especie de aguas profiindas (de 2,700 a 2,850 metros), asi como una significativa extension de rango. La especie de Nayarit, Mexico, Peltodoris nayarita, Ortea & Llera, 1981, es sinonima de la Diaulula greeleyi (MacFarland, 1905), originalmente nombrada del Brasil. La segunda parte de Behrens, 2004, se titula “Nueva Informacidn y Cambios en Nomenclatura.” Incluye extensiones de rango, datos ecologicos y cambios genericos. Por ejemplo, la especie Navanax inermis del sur de California, ahora ha sido reportada desde Western Society of Malacologists Annual Report Vol. 36, p. 25 Bolinas Lagoon en Marin County, en el norte de California. Previamente, el rango mas austral para Berthella californica era desde las Islas Coronados, junto a la frontera Mexico/E. U. Ahora su rango se extiende hasta las Islas Galapagos. El rango para Aegires aJhopimctatus se extiende al norte de la Columbia Britanica hasta Ketchikan, Alaska. Po/ycera tricolor se reporta en Ketchikan, Alaska; previamente, su ocurrencia mas septentrional era la Columbia Britanica. Tritonia myrakeenae, que originalmente se conocia desde Santa Barbara, California, hasta Isla Cedros, Baja California, ha sido reportada en Costa Rica. Babakina festiva se conocia desde Marin County, California, hasta Nayarit, Mexico, por toda nuestra costa. Tambien fue reportada originalmente desde Japon, y desde entonces se ha reportado que ocurre posiblemente en Espana y en Nueva Zelanda. Otra extension de rango reportado es que se ha colectado en las Bahamas, en el Atlantico oeste. La llamada “porostoma de branquia amarilla”, Doriopsilla gemela, tiene una masa de huevos casi aplanada, con grandes huevos lecitotroficos, en vez del tipico listen vertical enrollado con huevos pequehos, como los de otros miembros de su genero y la mayoria de los doridos. Bertsch (2002) report© la vida natural y ecologia de la Doriopsilla gemela en Bahia de los Angeles, basandose en mas de 10 anos de estudio en ese sitio del Mar de Cortes. La especie casi siempre ocurre sobre la esponja rosa Pseudosuberites pseudos y la esponja amarilla Cliona celata. Tiene un ciclo anual defmido, cuya nueva generacion aparece a principios del otono. Los siguientes son algunos de los muchos cambios genericos que reporta Behrens, 2004: Hopkins ia rosacea ahora esta en el genero Okenia. Laila cockerel I i se transfiere al genero Limacia, que tiene prioridad por fecha de publicacion. Tambja fusca es sinonima menor de Tambja abdere, en razon de prioridad de pagina. Anisodoris nobilis ha sido transferida al genero Peltodoris, con base en dates anatomicos que examino y describio Valdes (2002). Hay varias especies provinciales Panamicas (oeste tropical Americano) que ahora se han reportado en el sur de California. La costa exterior de Baja California, entre Bahia Magdalena y Punta Eugenia, es una region de transicion ecotonal a nivel provincial (Bertsch, 1993). Dentro de esta zona, bien puede esperarse que ocurran especies tropicales del sur, asi como especies del norte templado. Pero seria una clara excepcion que especies tropicales se extendiesen mas al norte (lo mismo aplica a la inversa). Behrens (2004) reporta que las especies realmente Panamicas tropicales cuya ocurrencia se ha reportado en aguas sudealifomianas, son las siguientes: Tritonia pickensi, Flabellina bertschi, Polycera alabe, Chromodoris galexomm y Aplysia parvula. Seria importante poder contrastar frecuencia y temporalidad de ocurrencia en aguas provinciales Panamicas tropicales, con la ocurrencia en aguas provinciales templadas del sur de California. La estacionalidad y temporalidad asociada a eventos de El Nino seria entonces bastante obvia. Asi que no serian realmente “extensiones de rango”, sino mas bien distribuciones periodicas hacia el norte influenciadas climaticamente. Estos dates son importantes para nuestro conocimiento de la biodiversidad marina. Para concluir, un comentario muy importante para nuestra comprension de la distribucion y vida natural de los invertebrados marines: Cuando hablamos del rango o distribucion de un organism©, no basta con solo decir que ocurre desde el punto X del sur, al punto Y del norte. Necesitamos explicar claramente el sitio donde se ha encontrado la mayoria de los especimenes. Necesitamos discutir porque las especies de una provincia zoogeografica se encuentran en otra. Las corrientes mueven muchas larvas, pero podrian no sobrevivir dadas las variaciones de Western Society of Malacologists Annual Report Vol. 36, p. 26 temperatura del agua. Pero ciertas veces si sobreviven y asi tenemos una extension del rango de especies tropicales hacia aguas templadas mas frias. Se requieren datos precisos para entender realmente la biodiversidad y biogeografia de los animales marinos. Por ejemplo, casi todos los especimenes de aves se reportan a una base de datos intemacional para llevar un buen registro de su estacionalidad, rareza o “excepciones” (ustedes saben, ese cierto pajaro por el que todos viajan miles de kilometros para verlo o fotografiarlo porque nunca antes se habia visto en Texas). Cada ano la Audubon Society patrocina un “conteo de aves”. Necesitamos hacer un esfuerzo similar para los invertebrados marinos. Defmitivamente hay suficientes buzos amantes de los nudibranquios como para hacer de esto una realidad. Quizas hasta llevar a cabo levantamientos dos veces por ano para tratar de entender las variaciones estacionales. [Nota agregada durante la preparacion del Reporte Anual (2007): Hay tres libros recientes que incorporan y actualizan estos datos: Behrens & Hermosillo, 2005, Camacho-Garcia, Gosliner & Valdes, 2005, y Hermosillo, Behrens & Rios Jara, 2006; veanse comentarios en Bertsch, 2007).] Agradecemos a Rosa del Carmen Campay por la traduccion al espanol. Opisthobranch fauna of Bahia de Banderas, Mexico (tropical eastern Pacific) Alicia Hermosillo Universidad de Guadalajara Guadalajara, Jalisco, C.P. 44600 Mexico E-mail: gueri25@hotmail.com Bahia de Banderas is located on the west coast of Mexico, in the states of Jalisco and Nayarit. This bay is the largest on Mexico's mainland. It is over 1,000 km and has 115 km of coastline, two major islands and numerous islets, rocks and sea mounts. Bahia de Banderas is characterized by complex hydrography and oceanography since it is the convergence point of three major current systems. The mean surface temperature is 26.4°C, varying from 20°C in April to 30°C in September. Its varied temperatures, hydrography and great size contribute to Bahia de Banderas' unique composition of opisthobranch fauna. Few reports have been published on the opisthobranch fauna of the northern coast of the Bay, in Nayarit. However, no reports have been published on the opisthobranch fauna of the central and southern sections of the Bay, along the coast of Jalisco. The goal of this work was to learn more about the opisthobranch fauna of Bahia de Banderas using SCUBA and intertidal collecting methods. The first 12 months, 30 sites that represent the habitats within the bay were visited randomly during various occasions. A species list was compiled. I selected the 10 sites with highest species richness. Shannon diversity index, abundance and representation of habitat. Since March 2003, surveys have been performed once a month to determine species presence and seasonality. Preliminary analyses of distribution and seasonality are presented in this work for some of the most abundant species in Bahia de Banderas: Tambja abdere Farmer, 1978, Lomanotus vermiformis Eliot, 1908, Hypselodoris agassizii (Bergh, 1894) and an undescribed Flabellina sp. Natural history and biogeography of these four species are reviewed. Western Society of Malacologists Annual Report Vol. 36, p. 27 Fauna de Opistobranquios de Bahia de Banderas, Mexico (Pacifico este tropical) Bahia de Banderas esta localizada en la costa oeste de Mexico, en los estados de Jalisco y Nayarit. Esta bahia es una de las mas grandes de Mexico con mas de 1,000 km^ y con 1 15 Km. de linea de costa. Cuenta con dos islas principales, numerosos islotes, rocas y montanas marinas. Bahia de Banderas se caracteriza por una hidrografia y oceanografia complejas, ya que es el punto de convergencia de tres sistemas de corrientes marinas. La temperatura superficial media es de 26.4 °C y varia de 20 °C en abril a 30 °C en septiembre. Su variedad de temperaturas, hidrografia y gran tamano contribuyen a que su composicion faunistica de opistobranquios sea unica. Se han publicado algunas referencias sobre la fauna de opistobranquios de la costa norte de la Bahia en Nayarit. Sin embargo, no se han publicado registros sobre la fauna de opistobranquios de las zonas centro y sur de Bahia de Banderas, a lo largo de la costa de Jalisco. El objetivo de este trabajo fue el de aprender mas acerca de la fauna de opistobranquios de la Bahia, utilizando inmersiones con equipo de buceo y metodos de recolecta en la zona intermareal. Durante los primeros 12 meses se visitaron aleatoriamente 30 sitios de muestreo que representaban los habitats propios de la Bahia. Se compile una lista de especies y se seleccionaron los 10 sitios con base en la mayor riqueza de especies, por el indice de diversidad Shannon, la abundancia y representatividad del habitat. Desde marzo de 2003 se han llevado a cabo valoraciones mensuales, para determinar la presencia de especies y su estacionalidad. Los analisis preeliminares de distribucion y estacionalidad se presentan en este trabajo, para algunas de las especies mas abundantes en Bahia de Banderas: Tambja abdere Farmer, 1978, Lomanotus vermifonnis Eliot, 1908, Hypselodoris agassizii (Bergh, 1894) y una especie no descrita del genero Flabellina. Se hace una revision de la historia natural y biogeografia de esas cuatro especies. A new species of Marionia from the Indo-Pacific region (Mollusca: Nudibranchia) Victor G. Smith'’^ and Terrence M. Gosliner’ 'Department of Invertebrate Zoology and Geology. California Academy of Sciences. Golden Gate Park. San Francisco, C A 941 18 USA ^San Francisco State University 1600 Holloway Avenue, San Francisco, CA 94132 USA E- mail: vsmith@calacademy.org Collections in the Philippines during 1992, 1994, and 1995, along with specimens from Indonesia collected during 1998, provide the basis for the description of a new species of tritoniid nudibranch. When the photographs of the animals were first examined, it was thought they represented two distinct species due to differences in color and pattern. However, careful examination did not reveal discemable differences in the external morphology or anatomy and characteristics of the reproductive and digestive organs. Marionia species "a" does not match any published descriptions of Indo-Pacific tritoniids, and is described herein. These animals have been recorded at depths of 6.1 to 22.9 m, with a maximum-recorded size of 60 mm alive. The animals have a pale green or yellow background color, with a pattern of dark red-brown lines or reticulations on the notum, a medial dorsal strip which is lighter in color and less distinctly Western Society of Malacologists Annual Report Vol. 36, p. 28 patterned, and transverse strips between the paired branchial plumes which are similarly lighter in color and pattern. The notal margin extends out over the sides of the body, and from it are produced 10 pairs of branchial plumes, and the unornamented sheaths of the rhinophores. The branchial plumes and the pinnate processes of the rhinophores are a darker red or green color, and the tips of the rhinophores are white. The oral veil contains 4 pairs of papillae, the innermost shortest and simple, the outermost being grooved oral tentacles, and the ones between usually with bifid apices. Most of the velar papillae are tipped with white. External genitalia are on the right side, between the second and third branchial plume. The anus and nephroproct are also on the right side, below the fourth branchial plume. Buccal armature includes a jaw with a single row of denticles giving a serrate appearance, and a radula with a tricuspid rachidian exhibiting distinctive folding, differentiated first lateral teeth, and hammate outer laterals. Cuticular plates are present in the stomach. Stomach contents reveal that one of the Philippine animals is feeding on octocorals of the family Ellisellidae (Gray, 1859). This is the second record of a nudibranch feeding on this family of octocoral. A new character of the reproductive system (a bilobed bursa copulatrix) is recorded for the first time. Una nueva especie At Marionia de la region del Indopacifico (Mollusca: Nudibranchia) Ejemplares recolectados en las Pilipinas en los anos 1992, 1994, y 1995, junto con especimenes de Indonesia recolectados en 1998, sustentan la base para la descripcion de una nueva especie de un nudibranquio tritonido. Cuando se hicieron los primeros analisis de las fotografias tomadas a estos animales, se penso que se trataban de dos especies distintas por sus diferencias en coloracion y patron caracteristico. Sin embargo, el examen detallado no mostro diferencias aparentes en la morfologia externa o anatomia y en las caracteristicas de los organos reproductivos y digestivos. La especie Marionia ‘a’ no concuerda con ninguna descripcion publicada de tritonidos del Indopacifico y se describe en este trabajo. Estos animales se han encontrado a profundidades de 6.1 a 22.9 m, con una talla maxima de 60 mm en ejemplares vivos. Los animales son verde palido o amarillos, con un patron de lineas de un cafe rojizo oscuro o reticulaciones sobre el notum, una banda media dorsal de un color claro y con un patron menos distintivo, y bandas transversales entre las plumas branquiales pareadas, las cuales son ligeramente similares en color y patron. El margen notal se extiende hacia afuera sobre los lados del cuerpo y de ahi surgen 10 pares de plumas branquiales y las hojas no omamentadas de los rinoforos. Las plumas branquiales y los procesos pinados de los rinoforos son rojo obscuro o verdes, y las puntas de los rinoforos son blancas. El velo oral contiene 4 pares de papilas, la mas interna corta y simple, la externa con tentaculos orales acanalados y la de en medio usualmente con apices bifidos. La mayor parte de la papila velar esta moteada de bianco. Los genitales extemos estan en el lado derecho, entre la segunda y tercer pluma branquial. El ano y el nefroprocto estan tambien en el lado derecho, por debajo de la cuarta pluma branquial. La armadura bucal incluye una mandibula con una linea simple de denticulos dando una apariencia aserrada, y una radula con forma triciispide mostrando pliegues distintivos, diferenciando el primer diente lateral y laterales externos armados. Se presentan placas cuticulares en el estdmago. El contenido estomacal de un animal de las Pilipinas revelo que se alimenta de octocorales de la familia Ellisellidae (Gray, 1859). Este es el segundo registro de un nudibranquio que se alimenta de esta familia de octocorales. Se observd por primera vez un nuevo caracter del sistema reproductivo (una bursa copulatrix bilobulada). Western Society of Malacologists Annual Report Vol. 36, p. 29 Two new species of dorid nudibranchs (Mollusca, Opisthobranchia) from the Mar de Cortes, Baja California, Mexico Hans Bertsch and Angel Valdes Natural History Museum of Los Angeles County ' 192 Imperial Beach Blvd. #A, Imperial Beach, CA 91932 USA E-mail: hansmarvida@sbcglobal.net ^900 Exposition Blvd., Los Angeles, CA 90007 USA E-mail: avaldes@nhm.org Bahia de Los Angeles (BLA) has an intriguing and eontrasting biota. Because of the rain shadow effect that blocks most rainfall from the Pacific Ocean, the terrestrial habitat is excruciatingly barren and depauperate. However, because of upwelling caused by currents and tidal flow between Isla Angel de la Guarda and the peninsula, the marine environment is faunistically rich: the spring benthic algal bloom carpets the bottom and extends into the water column; numerous marine birds nest and breed on the islands; over 10 species of cetaceans are known from the region; and the magnificent filter-feeding whale shark, Rhincodon typus, seasonally appears in the bay and its environs. The bay is located about 600 km south of the U.S.-Mexican border (29° N; 113° 32' W). Inside the bay are a number of islands that provide distinct habitats for marine organisms and roosting sites for marine birds. The nudibranch fauna is remarkably rich. The type localities of ten species are in the BLA area. Okenia angelensis Lance, 1966, was named from the “lowest intertidal zone, BLA.” Cerberilla pugnoarena Collier & Farmer, 1964, and Eubranchus cucullus Behrens, 1985, were named from Puerto Refugio, Isla Angel de la Guarda. Cuthona longi Behrens, 1985, was named from Isla Raza, and Dendrodoris stohleri Millen & Bertsch, 2005, from Punta la Herradura. Five species cite Punta la Gringa (about 10 km north of town) as their type locality: Bajaeolis bertschi Gosliner & Behrens, 1986; Polycerella glandulosa Behrens & Gosliner, 1988; Trapania goslineri Millen & Bertsch, 2000; Peltodoris lancei Millen, in Millen & Bertsch, 2000; and Okenia angelica Gosliner & Bertsch, 2005. During the last 20 + years, HB has been performing regular research on the opisthobranchs at Punta la Gringa. In addition to new species, these studies have yielded information about the biogeography and distribution, community structure, ecology and natural history of these gastropod mollusks. In this presentation, we will give a preliminary description of two new species (one each from the genera Diaulula and Peltodoris) that were collected by HB at Punta la Gringa. Of special note, is that these new species are so different from known species within these genera, that even though only one specimen of each has been seen, they are obviously distinct, and warrant designation as new species. Dos especies nuevas de nudibranquios doridos (Mollusca, Opisthobranchia) del Mar de Cortes, Baja California, Mexico Bahia de Los Angeles (BLA) posee una biota intrigante y contrastante. Debido al efecto de sombra que impide la mayoria de las Iluvias del Oceano Pacifico, el habitat terrestre es extremadamente arido y pauperrimo. Sin embargo, debido a las surgencias causadas por las corrientes y el regimen mareal entre Isla Angel de la Guarda y la peninsula, el ambiente marino es faunisticamente rico: las afloraciones de algas bentonicas en primavera cubren el fondo y se Western Society of Malacologists Annual Report Vol. 36, p. 30 extienden hacia la columna de agua; numerosas aves marinas anidan y se aparean en las islas; mas de 10 especies de cetaceos se conocen en la region y el majestuoso tiburon ballena, Rhincodon typus, aparece estacionalmente en la bahia y sus alrededores. La bahia esta localizada a unos 600 Km. al sur de la frontera de Mexico con los Estados Unidos (29°E N; 113° 32' O). Dentro de la bahia hay varias islas que proveen habitats distintos para los organismos marinos y lugar de descanso para las aves marinas. La fauna de nudibranquios es particularmente rica. Las localidades tipo para diez especies estan en el area de BLA. Okenia angelensis Lance, 1966, fue nombrada como “de la zona intermareal baja, de BLA”. Cerberilla pugnoarena Collier & Farmer, 1964 y Eubranchus cucidliis Behrens, 1985, fueron nombradas para Puerto Refugio, Isla Angel de la Guarda. Cuthona longi Behrens, 1985, fue nombrada desde Isla Raza, y Dendrodoris stohleri Millen & Bertsch, 2005, desde Punta la Herradura. Cinco especies se refieren a Punta la Gringa (aproximadamente a 10 Km. al norte de la ciudad) como su localidad tipo: Bajaeolis bertschi Gosliner & Behrens, 1986; Polycerella glandidosa Behrens & Gosliner, 1988; Trapania goslineri Millen & Bertsch, 2000; Peltodoris lancei Millen en Millen & Bertsch, 2000; y Okenia angelica Gosliner & Bertsch, 2004. Durante mas de 20 anos, el co-autor HB ha llevado a cabo investigaciones sobre opistobranquios en Punta la Gringa. Ademas de dos nuevas especies, esos estudios han brindado informacion acerca de la biogeografia y distribucion, la estructura de la comunidad, la ecologia y la historia natural de esos moluscos gasteropodos. En esta presentacion, daremos una descripcibn preeliminar de las dos nuevas especies (una de ellas del genero Diauhda y otra del genero Peltodoris) que fueron recolectadas por HB en Punta la Gringa. Cabe destacar, que esas especies nuevas son muy diferentes de las conocidas dentro de esos generos y que aun y cuando s61o un especimen de cada una de ellas ha sido encontrado, evidentemente se tratan de especies distintas, lo que garantiza esta designacion. III. PHYLOGENETICS SESSION SESION FILOGENETICA Organized by/ Organizado por Douglas J. Eemisse California State University, Fullerton USA Revival of the genus Cyanoplax Pilsbry, 1892, for a clade of west coast chitons Douglas J. Eemisse Department of Biological Science California State University, Fullerton, CA 92834-6850 USA E-mail deemisse@fullerton.edu Before Kaas and Van Belle (1981: Zool. Verb. 185: 1-43) and Ferreira (1982: Veliger 25: 93-138) concluded that Cyanoplax Pilsbry, 1892 (type species: Chiton hartwegii Carpenter, 1855) was a junior synonym of Lepidochitona Gray, 1821 (type species: Chiton cinereus Linnaeus, 1767), most treatments of West Coast chitons had used Cyanoplax for an assemblage of small chitons with rather unremarkable shell and girdle features. West coast members of this genus do show considerable interesting variation in their parental care (free spawning vs. Western Society of Malacologists Annual Report Vol. 36, p. 31 brooding) and sexual reproduction (separate sexes vs. simultaneous hermaphrodites with self- fertilization). My own studies contrasting reproductive patterns between these species (Eemisse, 1988: Biol. Bull. 174: 287-302) were somewhat limited because the phylogenetic relationships among the seven studied Lepidochitona spp. were only partly resolved and because the other worldwide members of Lepidochitona were not included. In order to address these limitations, I have sequenced two mitochondrial gene regions for representatives of all of the available West Coast members of Lepidochitona, selected Atlantic/Mediterranean/Caribbean members of this genus, and a diversity of outgroup species. The results clearly indicate that the West Coast species that have been included in this genus are not at all closely related to a monophyletic grouping of Lepidochitona species sampled from the northern Atlantic and Mediterranean Sea. The latter should retain the genus name because it includes the type species for the genus, L. cinerea. The West Coast species are a completely separate monophyletic lineage, here provisionally referred to once again as Cyanoplax Pilsbry, 1892. Preliminary evidence indicates that the sister taxon of Cyanoplax is comprised of Nuttallina spp. (itself monophyletic) plus L. beanii from the Gulf of California, L. Hozonis from the Caribbean, and L. turtoni from South Africa. Dendrochiton Berry, 1911, which Kaas and Van Belle have considered to be a subgenus of Lepidochitona, has instead been resolved as sister taxon of Mopalia Gray, 1847, and this makes some sense because the members of Dendrochiton and Mopalia resemble each other in bearing setiose hairs on their girdle. Tonicella Carpenter, 1873, which Kaas and Van Belle have considered to be in the same subfamily as Lepidochitona, instead appears to have closer affinities to other members of a mostly northern Pacific clade that includes Mopalia, Dendrochiton, and Cryptochiton Middendorff, 1847. This improved resolution for Cyanoplax spp. has made it possible to study the evolution of reproductive traits such as brooding and hermaphroditism within the genus. Reestablecimiento del genero Cyanoplax Pilsbry, 1892, para un dado de quitones de la costa oeste Antes de Kaas y Van Belle (1981: Zool. Verb. 185: 1-43) y Ferreira (1982: Veliger 25: 93- 138) se concluyo que Cyanoplax Pilsbry, 1892 (especie tipo: Chiton hartwegii Carpenter, 1855) era un sinonimo de Lepidochitona Gray, 1821 (especie tipo Chiton cinereus Linnaeus, 1767). En la mayoria de los compendios sobre quitones de la costa Oeste han utilizado el genero Cyanoplax para agrupar a pequenos quitones con una concha no remarcada y con rasgos acintados. Los miembros de la costa Oeste de este genero muestran una considerable variacion respecto al cuidado parental (desoves fibres vs. crianza) y a su reproduccidn sexual (sexos separados vs. hermafroditas simultaneos con auto fertilizacion). Mis propios estudios contrastando los patrones reproductivos entre esas especies (Eemisse, 1988: Biol. Bull. 174: 287-302) han sido algo limitados debido a que las relaciones filogeneticas entre las siete especies de Lepidochitona estudiadas solo fueron resueltas parcialmente y porque los otros miembros de Lepidochitona de otras partes del mundo no se incluyeron. Para resolver estas limitantes, he secuenciado dos regiones del gen mitocondrial con representantes de todos los miembros disponibles de Lepidochitona en la Costa Oeste, representantes seleccionados de este genero del Atlantico - Mediterraneo - Caribe y una diversidad de especies fuera del gmpo. Los resultados indican claramente que las especies de la Costa Oeste que han sido incluidas en este genero, no estan del todo cercanamente relacionadas con una agrupacion monofiletica de las especies de Lepidochitona muestreadas en el norte del Atlantico y mar Mediterraneo. El ultimo debiera Western Society of Malacologists Annual Report Vol. 36, p. 32 conservar el nombre generico debido a que incluye a la especie tipo del genero, L. cinerea. Las especies de la Costa Oeste constituyen un linaje monofiletico completamente separado, que aqui referiremos provisionalmente como Cyanoplax Pilsbry, 1892. Evidencias preeliminares indican que el taxon hermano de Cyanoplax esta compuesto por Nuttallina spp. (Monofiletico en si mismo) mas L. heanii del Golfo de California, L. liozonis del Caribe, y L. turtoni de Sud Africa. Dendrochiton Berry, 1911, el cual Kaas y Van Belle ban considerado ser un sub genero de Lepidochitona, tiene por lo tanto que ser considerado como un taxon hermano de Mopalia Gray, 1847; lo cual tiene sentido porque los miembros de Dendrochiton y Mopalia se parecen uno al otro. Tonicella Carpenter, 1873, el cual Kaas y Van Belle han considerado que estan en la misma subfamilia como Lepidochitona, tambien parecen tener mayor afmidad con otros miembros del dado del norte del Pacifico que incluye Mopalia, Dendrochiton y Cryptochiton Middendorff, 1847. Esta nueva conclusion para Cyanoplax spp. ha hecho posible estudiar la evolucion de los rasgos reproductivos como la crianza y el hermafroditismo dentro del genero. A new method for genome size estimation in Haliotis rufescens (Archaeogastropoda: Haliotidae) using dapi-fluorescence fading Cristian Gallardo Escarate , Josue Alvarez Borrego and Miguel Angel del Rio Portilla 'Division de Ocenaologia Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107, Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail; gallardo@cicese.mx ^Division de Fisica Aplicada CICESE, Km 107, Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico Nuclear genome size is an important characteristic of a species which determines the capacity of that species to undergo evolutionary change. This type of analysis may be especially useful in biodiversity studies and determination of ploidy levels in genetically manipulated species. Several methods have been used to quantify genome size. DNA extraction has been reported as imprecise, because it is necessary to determine the number of nuclei from which the DNA is extracted. An alternative technique, using the quantification of fluorescence intensity in nuclei stained with DNA-specific fluorochromes. This technique has been widely applied in flow cytometry and with great success in determinating genome size. However, this method requires both for the sample to be in suspension and for a large number of nuclei to analyze. Recently, densitometric techniques using Feulgen reaction combined with image analysis has been demonstrated to be useful and a simple method for genome size estimation. The disadvantage of this technique is the Feulgen stain protocol. Basically, the Feulgen stain requires a strong hydrolysis with hydrochloric acid 1 N at 60°C or 5 N at 20-30°C, which will affect the efficacy of the stain. In this work, we present a new method for genome size estimation using DAPI- fading fluorescence (DFF) combined with image analysis processing. Fluorescence fading is a phenomenon which occurs when a fluorochrome is excited by a specific wavelength light and its fluorescence intensity deereases with time. The hypothesis considered in this work is that fluorescence fading is proportional to genome size. Red abalone spermatozoa were stained with DAPI. Digital images were taken every 1.6 sec. during 800 sec. and computer analyzed. Western Society of Malacologists Annual Report Vol. 36, p. 33 Fluorescence fading was plotted against time and the area under the curve was considered to be related with the cell DNA content. Tilapia (Oreochromis mossambicus) sperm and red blood cells were used for comparison of genome size. Our results show that the measurement of DFF in Haliotis rufescens spermatozoa is a mathematic function of the DDF value in O. mossambicus (C=0.81 pg). The genome size in H. rufescens was estimated in C=1 .76 pg. Un nuevo metodo para la estimacion del tamafio genomico en Haliotis rufescens (Archaeogastropoda: Haliotidae) mediante desvanecimiento dapi-fluorescente Una importante caracteristica en las especies es el tamano gen6mico nuclear, el cual determina la capacidad de la especie de experimentar cambios evolutivos. Este tipo de analisis puede ser especialmente util en estudios de biodiversidad y determinacion de niveles de ploidia en especies geneticamente manipuladas. Diversos metodos han sido utilizados para cuantificar el tamano gendmico. El metodo de extraccion de ADN ha sido descrito como impreciso, debido a que es necesario determinar el numero de nucleos de los cuales se extrajo el ADN. Una tecnica altemativa, utiliza la cuantificacion de la intensidad de fluorescencia en nucleos tenidos con fluorocromos especificos para ADN. Esta tecnica ha sido ampliamente aplicada en procedimientos de citometria de flujo y con gran exito en la determinacidn de tamano gendmico. Sin embargo, este metodo requiere que la muestra se encuentre en suspension, ademas de gran numero de nucleos por analisis. Recientemente, tecnicas densitometricas utilizando la reaccion de Feulgen combinada con analisis de imagenes han demostrado ser utiles y son un metodo sencillo para estimar tamano gendmico. La desventaja de este metodo involucra el protocolo para la tincidn de Feulgen. Basicamente, la tincidn de Feulgen requiere una.fuerte hidrdlisis con Acido hidroclorhidrico 1 N a 60°C d 5 N a 20°C, el cual puede afectar la eficiencia de la tincidn. En este trabajo, presentamos un nuevo metodo para estimar el tamano gendmico usando desvanecimiento DAPI-fluorescente (DDF), combinado con procesamiento de analisis de imagenes. El desvanecimiento de la fluorescencia es un fendmeno que ocurre cuando un fluorocromo es excitado por una longitud de onda especifica y su intensidad de fluorescencia disminuye con el tiempo. La hipdtesis considerada en este trabajo, es que el desvanecimiento de la fluorescencia es proporcional al tamano gendmico. Espermatozoides de abuldn rojo fueron tenidos con DAPI. Imagenes digitales fueron capturadas cada 1.6 s durante 800 s y analizadas por computadora. El desvanecimiento de la fluorescencia fue graficado a traves del tiempo y el area bajo la curva fue considerada como relativo al contenido de ADN celular. Espermatozoides y gldbulos rojos de tilapia {Oreochromis mossambicus) fueron utilizados para comparar el tamano gendmico. Nuestros resultados muestran que las mediciones de DDF en espermatozoides de Haliotis rufescens son una funcidn matematica del valor de DDF en O. mossambicus (C=0.81 pg). El tamano gendmico en H. rufescens fue estimado en C=L76 pg. Western Society of Malacologists Annual Report Vol. 36, p. 34 Phylogeography and diversity of the eastern Pacific coast David Jacobs, Todd Haney and Kristina Louie Department of Organismic Biology, Ecology, and Evolution University of California, Los Angeles 621 Charles E. Young Drive South, Los Angeles, CA 90095-1606 USA E-mail djacobs@ucla.edu The global climate and geologic record document a transition to upwelling in the middle Miocene (@15-mya). Paleontologic and molecular clocks indicate that a significant component of the uniquely diverse temperate marine fauna of the coastal North Pacific radiated at this time. This diversity appears to have been sustained in the North Pacific through hiatuses in upwelling in the Pliocene and Pleistocene that eliminated diversity in other upwelling regions around the world. An additional historical factor is the presence of significant embayments along the California coast in the Miocene and Pliocene that supported warm water faunas. Upwelling and embayments are the likely sources of much of the faunal diversity now found in the Gulf of California. Filogeografia y diversidad de la costa Pacifico del este El clima global y el registro geolbgico documentan una transicibn hacia un afloramiento en el Mioceno medio (@15-mya). Los relojes paleontolbgicos y moleculares indican que un componente significative, de la particularmente diversa fauna marina templada de la costa norte del Pacifico, irradib en este tiempo. Esta diversidad parece haber sido sostenida en el Pacifico Norte mediante interrupciones en afloramientos en el Pliocene y Pleistocene que eliminaron la diversidad en otras regiones de afloramientos alrededor del mundo. Un factor historico adicional es la presencia de bahias a lo largo de la costa de California en el Mioceno y Pliocene que favorecieron el desarrollo de fauna de aguas calidas. Afloramientos y bahias parecen ser las fuentes de gran parte de la diversidad faunistica que actualmente encontramos en el Golfo de California. Morphometric analysis of Chione cortezi and C. fluctifraga (Bivalvia: Veneridae) of Gulf of California, Mexico Ana Livia Licona Chavez , Francisco Correa Sandoval and Faustino Camarena 'institute de Investigaciones Oceanolbgicas, Universidad Autbnoma de Baja California Km. 107 Carretera Tijuana-Ensenada. A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico E-mail licona_99@yahoo.com ^Facultad de Cencias, Universidad Autbnoma de Baja California Km. 107 Carretera Tijuana-Ensenada, Ensenada, Baja California, C.P. 22860 Mexico The species Chione cortezi and C. fluctifraga have been assigned to the subgenus Chionista (Keen, 1958) based on their conehological characteristics. However, in some reports, the two species have been considered the same. Chione cortezi can grow to 88 mm, which makes it an important commercial species. In the 1980’s, the geographic distribution of C. cortezi extended from Bahia Magdalena Baja California (Pacific coast of Mexico) to Guaymas Sonora (Gulf of Western Society of Malacologists Annual Report Vol. 36, p. 35 California). Nevertheless, in the last years, C. cortezi has been found only in the Alto Gulf of California, and it was considered endemic for this area. Chione fluctifraga (the "black clam") can grow to 51 mm. The objective of this work was to analyze the grade of morphological differentiation between C. cortezi and C. fluctifraga found in five localities of the Gulf of California. Twelve morphometric variables (characters of hinge, adductor muscle, escutcheon and lunule) were considered. The proportions of each one of the variables in relation to maximum valve length were analyzed according to the Discriminating Function Analysis (DFA) in order to determine which morphological features have the greatest important in differentiating between each locality and species. In addition, the Square Distance of Mahalanobis (D^) was calculated to know the distributions of morphological distances between samples from each location of C. cortezi ("A"), C. fluctifraga ("B"), and unclassified specimens (species "C"). The DFA demonstrated that the morphological variables analyzed were able to differentiate between localities of the same species, and even between species, with an 88% rate of correct classification. The distance between the two localities of C. cortezi was less (D = 5) than that between C. fluctifraga — C. cortezi (D =14 to 21). The distance between C. fluctifraga — species "C" was less (D = 8) than the range between C. cortezi — species "C" (D = 9 to 18). This analysis determined that species "C" possesses morphometric characteristics of C. fluctifraga, as many authors have classified it. Nevertheless, genetic population studies (allozyme electrophoresis) of these same groups determined that species "C" is genetically similar to C. cortezi. For those species in a similar situation, we suggest studies using our methodology, which integrates methods of morphometric analysis and population genetics. Analisis morfometrico de Chione cortezi y C. fluctifraga (Bivalvia: Veneridae) del Golfo de California, Mexico Las especies Chione cortezi y C. fluctifraga fueron asignadas al Subgenero Chionista (Keen, 1958) debido a sus caracteristicas conquiologicas. Sin embargo, existen reportes en los que se cita a una u otra especie de manera indistinta como si se tratara de una sola. C. cortezi es una especie que alcanza tallas de hasta 88 mm por lo que es capturada con fines comerciales. En la decada de los 80, el area de distribucion geografica abarcaba desde Bahia Magdalena, en el Pacifico mexicano, hasta Guaymas (Sonora). Sin embargo, recientemente solo se encontro en el Alto Golfo de California, por lo que fue considerada especie endemica de esta zona. C. fluctifraga es llamada comunmente almeja negra y es consumida regionalmente como almeja coctelera, alcanzando tallas de hasta 5 1 mm. Debido a esta situacion, en esta investigacion se analizo el grado de diferenciacion morfometrica entre C. cortezi y C. fluctifraga procedentes de cinco localidades del Golfo de California. Se consideraron 12 variables morfologicas que representan caracteristicas de la bisagra, musculo abductor, estuche y lunula. Las proporciones de cada una de las variables en relacion a la longitud maxima de la valva se analizaron mediante el Analisis de Funeiones Discriminantes (AFD) para determinar cuales caracteristicas morfometricas tienen mayor importancia en la diferenciacion de cada una de las localidades y especies. Ademas, se calcularon las Distancias Cuadradas de Mahalanobis (D^) para conocer las distribuciones de las distancias morfometricas entre las muestras de las diferentes localidades: C. cortezi (especie A), C. fluctifraga (especie B) y entre organismos no clasificados de dos localidades (especie C). El AFD mostro que las variables morfometricas analizadas fueron utiles para diferenciar entre dos localidades de una misma especie e incluso entre especies con un porcentaje total de clasificacion correcta de las muestras del 88%. La distancia entre dos Western Society of Malacologists Annual Report Vol. 36, p. 36 2 2 localidades de C. cortezi fue menor (D =5), que entre las especies C. fluctifraga-C. cortezi (D = 14 a 21). La distancia entre C. fluctifraga-Gspecie C fue menor (D = 8) comparado al rango de C. cortezi -QspQcie “C” (D^= 9 a 18). Con este analisis se logro determinar que la especie “C” posee caracteristicas morfometricas propias de C. fluctifraga, por lo que muchos autores la han clasificado de esta manera. Sin embargo, estudios de genetica de poblaciones (electroforesis de alozimas) de estas mismas poblaciones revelaron que la especie catalogada como “C” es geneticamente similar a C. cortezi. Para aquellas especies que presentan esta misma situacion, se sugiere aplicar un enfoque similar al del presente estudio, en el cual se integren los metodos de analisis de la morfometria y de la genetica de poblaciones. Genetic characterization of some populations of Chione californiensis and C. subimbricata (Bivalvia: Veneridae) in the Gulf of California and Pacific coast of Mexico Ana Livia LiconaChavez , Francisco Correa Sandoval y Jorge de la Rosa 'institute de Investigaciones Oceanologicas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada, A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico E-mail licona_99@yahoo.com ^Facultad de Ciencias Marinas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada. A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico Of the 25 species of Chione distributed in North Pacific waters, 15 species are found in the peninsula of Baja California. The species C. californiensis and C. subimbricata belong to the subgenus Chione. The commercial species C. californiensis, distributed from California, USA, to Peru is harvested commercially. However, C. subimbricata, found from the Gulf of California to Peru, is considered to have ecological importance. This is the first report about the determination of the population genetics of this species. The enzymes were extracted from homogenized tissues of the digestive gland and adductor muscle. Between 24 and 36 clams were obtained for experimentation. Chione californiensis was obtained from three different localities from the coasts of the Gulf of California (states of Baja California Sur and Sonora) and C. subimbricata was obtained from one locality of the Pacific coast of Mexico (state of Jalisco). The enzymes were analyzed by electrophoresis (PAGE) for 22 enzymatic systems. Between 18 and 21 loci were obtained from C. californiensis and 9 loci from C. subimbricata. For C. californiensis, 15 loci were not in Hardy- Weinberg (HW) equilibrium, 10 had heterozygote deficiency and 5 had heterozygote excess (p^O.OOl). For C. subimbricata, 1 locus was not in HW equilibrium, and another has heterozygote deficiency (p^O.OOl). The expected heterozygosity (He) varied from 0.456±0.032 to 0.466±0.025 for C. californiensis. The He for C. subimbricata was 0.457±0.050. The genetic identity of Nei was higher between the two subpopulations of Baja California Sur (1=0.936) than among them and the population of Sonora. The genetic identity between C. californiensis and C. subimbricata was the highest (1=0.897), when other species such as C. cortezi, C. fluctifraga and C. gnidia were included in the analysis. These results agree with the report of the inclusion of C. subimbricata in the subgenus Chionopsis. The inbreeding coefficient of C. californiensis (FIS=0.120) showed intrapopulation homogeneity. The fixation index (FST=0.046) showed a reduced population structure and the Global Inbreeding Coefficient (FIT=0.162) showed that there is no reproductive isolation among the organisms from the Western Society of Malacologists Annual Report Vol. 36, p. 37 different localities. Although few localities were studied in this work, we found a strong association between the patters of oceanic circulation and the F statistics, which indicated an effect over the population structure of C. californiensis. Further work is recommended by increasing the number of loci and the geographic populations of each species to understand the intra- and interspecific relationships as well as the effect of the oceanographic factors on the population structure. Caracterizacion genetica de algunas poblaciones de Chione californiensis y C. subimbricata (BivalviaiVeneridae) en el Golfo de California y el Pacifico Mexicano En la Peninsula de Baja California, Mexico se registran 25 especies de Chione de las cuales 15 se distribuyen en el Pacifico Americano. De acuerdo con Keen (1971) las especies C. californiensis y C. subimbricata pertenecen al Subgenero Chione. C. californiensis habita desde California, EE.UU. a lo largo del Golfo de California hasta Peru, es una especie explotada comercialmente a nivel regional. C. subimbricata tiene una distribucion geografica mas restringida desde el Golfo de California hasta Peru y su importancia es fundamentalmente ecologica. El objetivo de la presente investigacion fue determinar el grado de diferenciacion genetica, la estructura poblacional y la identidad genetica Nei (I) por medio del analisis de alozimas. Este estudio es el primero en su tipo ya que no existen antecedentes de estudios publicados sobre genetica de poblaciones de esta especie. Las enzimas se extrajeron de homogeneizados de glandula digestiva y musculo abductor de entre 24 y 36 almejas procedentes de tres localidades de las costas del Golfo de California, Mexico (Sonora y Baja California Sur) de C. californiensis y de una localidad del Pacifico mexicano (Jalisco) de C. subimbricata. Se analizaron en electroforesis en geles de poliacrilamida para 22 sistemas enzimaticos de los cuales se obtuvieron entre 1 8 y 2 1 loci para C. californiensis y 9 loci para C. subimbricata. De los loci ensayados para C. californiensis 15 se desviaron del Equilibrio de Hardy-Weinberg (EHW), 10 tuvieron deficiencia de heterocigotos significativa y 5 exceso de heterocigotos significativa (p<0.001). En C. subimbricata de los 9 loci obtenidos, uno se desvio del EHW y otro presento deficiencia de heterocigotos significativa (p<0.001). La heterocigosidad esperada (He) vario de 0.456±0.032 a 0.466±0.025 para C. californiensis y de 0.457±0.050 para C. subimbricata. La similitud genetica de Nei fue mayor entre las dos subpoblaciones de Baja California Sur (1=0.936) que entre estas y la poblacion de Sonora. Entre las dos especies C. californiensis y C. subimbricata la similitud genetica (1=0.897) file la mas elevada cuando en el analisis se incluyen a otras especies como C. cortezi, C. fluctifraga ambas del Subgenero Chionista y C. gnidia del Subgenero Chionopsis. Estos resultados concuerdan con la inclusion de C. subimbricata dentro del subgenero Chionopsis como lo propuso Keen. El coeficiente de endogamia C. californiensis (FIS=0.120) demostro la existencia de homogeneidad intrapoblacional. El indice de fijacion (FST=0.046) indico una reducida estructuracion poblacional y el Coeficiente de Endogamia Global (FIT=0.162) revel6 que no existe aislamiento reproductivo de los organismos de las distintas localidades. A pesar del reducido niimero de localidades incluidas en el presente estudio, es evidente la asociacidn entre los patrones de circulacion oceanica y los estadisticos F que indicaron un efecto sobre la estructura poblacional de C. californiensis. Se recomienda ampliar los estudios sobre la caracterizacidn genetica de las especies de este genero, incrementando el niimero de loci y de poblaciones geograficas de cada especie con el fin de dilucidar mas claramente las relaciones dentro y entre las especies asi como el efecto de los factores oceanograficos sobre la estructura poblacional. Western Society of Malacologists Annual Report Vol. 36, p. 38 DNA sequence test of the lined chiton (Tonicella) species complex Reuben L. Paul and Douglas J. Eemisse Department of Biological Science California State University, Fullerton, CA 92834-6850 USA E-mail: primevalsound@hotmail.com West Coast chitons commonly known as lined chitons have long been identified as Tonicella lineata (Wood, 1815) but, in 1999, R. N. Clark proposed that these were actually a species complex comprised of four distinct species, two of which Clark described as new. However, the criteria Clark used to make these distinctions were primarily related to the shell coloration patterns, which had been previously interpreted as mere intraspecific variations. In his favor, the color and line-pattern variants appeared to have different, albeit somewhat overlapping, geographical and bathymetric distributions. DNA sequence comparisons were thus employed to test the validity of Clark’s hypothesized species distinctions. Of the four Tonicella species considered by Clark, our study emphasized the two that most commonly live in intertidal habitats: T. lineata (ranging from Alaska to central California) and T. lokii (ranging from northern to central California). According to Clark, these putative species differ most obviously in the pattern of lines on the head shell plate, with either a “gothic arch” {T. lineata) or a zigzag {T. lokii) pattern of arching lines. Portions of the mitochondrial genes, cox I and 16S ribosomal DNA, were compared in this study in order to analyze genetic variation among sampled individuals. Our results strongly support Clark’s distinctions between T lineata and T. lokii, as well as the monophyly of each. For example, T. lineata from central California (where it is rare) grouped unambiguously with T. lineata from Washington and Alaska, not with central California T. lokii. An unanticipated result was our preliminary discovery of phylogeographic separation among populations of T. lokii from Monterey and San Luis Obispo counties in central California, whereas T lineata showed no such structure throughout its much greater range (Alaska to California). In comparison to the included outgroups, we also supported the monophyly of a group comprised of T. lineata, T lokii, and the other of Clark’s new species, T. venusta, however it will likely require further sampling of T. venusta to resolve relationships among these three species. Likewise, we expect to extend these sequence comparisons to additional populations, other Tonicella spp., and additional outgroups in order to better resolve relationships within this genus. Prueba de secuenciacion de ADN para el complejo de especies de Quiton Ray ado Tonicella) Los quitones de la Costa Oeste comunmente conocidos como quitones rayados han sido ampliamente identificados como Tonicella lineata (Wood, 1815) pero, en 1999, R. N. Clark propuso que estos forman un grupo de cuatro especies distintas, dos de las cuales Clark ha descrito como nuevas. Sin embargo, el criterio que utilize Clark para hacer esas distinciones primeramente esta relacionado con los patrones de coloracion de la concha, los cuales previamente han sido interpretados como resultado de variaciones intraespedficas. A favor de las deducciones de Clark, las variaciones en el color y los patrones lineales parecen estar relacionados con una distribucidn geografica y batimetrica diferente, aiin cuando hay ciertas sobreposiciones. Para probar la validez de las observaciones de Clark se emplearon comparaciones de secuenciacidn de ADN. De las cuatro especies de Tonicella consideradas por Western Society of Malacologists Annual Report Vol. 36, p. 39 Clark, nuestro estudio destaco a dos de ellas que habitan en el intermareal: T. lineata (que se distribuye desde Alaska hasta California central) y T. lokii (que habita del norte al centro de California). De acuerdo con Clark, estas especies putativas difieren marcadamente en su patron de lineas sobre la concha, T. lineatta presenta una especie de “arco gotico” mientras que T. lokii presenta un patron en zigzag de lineas arqueadas. Se compararon los fragmentos de los genes mitocondriales, cox 1 y el 16S ribosomal ADN, fueron comparados en este estudio para analizar la variacion genetica entre los individuos muestreados. Los resultados apoyan fuertemente las diferenciaciones de Clark entre T. lineata y T. lokii, asi como la monofilia de cada uno. For ejemplo, T. lineata de California central (donde es raro) se agrupo inequivocamente con T. lineata de Washington y Alaska, y no con T. lokii de California central. Un resultado anticipado fue nuestro descubrimiento preeliminar de la separacion filogenetica de T. lokii de los condados de Monterey y San Luis Obispo en California central, mientras que T. lineata no mostro tal estructura en todo su amplio rango de distribucion geografica (Alaska a California). En comparacion a los grupos extemos, apoyamos la monofilia del grupo comprendido por T. lineata, T. lokii, y la otra nueva especie de Clark, T. venusta', sin embargo, se requieren de muestreos adicionales de T. venusta para resolver las relaciones entre estas tres especies. Igualmente, esperamos extender estas comparaciones de las secuencias en poblaciones adicionales, otras Tonicella spp., y otros grupos adicionales para dilucidar las relaciones dentro de este genero IV. AQUACULTURE SESSION SESION ACUACULTURA Organized by/ Organizado por Carmen Guadalupe Paniagua Chavez Departamento de Acuicultura, CICESE, Mexico The rainbow lip pearl oyster Pteria sterna cultured in Bahia de La Paz: Tradition and modernity I *2 Carlos Caceres Martinez and Jorge Chavez Villalba 'Universidad Autonoma de Baja California Sur, A.P. 19-B La Paz, Baja California Sur, C.P. 23080 Mexico E-mail: ccaceres@uabcs.mx ^Centro de Investigaciones Biologicas del Noroeste (CIBNOR) Unidad Guaymas, A.P. 349, Guaymas, Sonora, C.P. 85465 Mexico Pearl oyster culture in Bahia de La Paz (BLP) was very famous at the end of the XIX century because of the technical advances employed at that time. The main products were mother of shell (used for buttons) and natural pearls. Nevertheless, oyster culture ended with social conflicts and the Mexican revolution of 1910. Many efforts were invested in the second half of the past century to bring back the activity but the results of different research groups were not rewarded until 1980, when natural beds had recovered and the feasibility of pearl culture was realized. The commercial culture of pearl oysters in BLP restarted in 1999, using the natural spat fall of the rainbow lip pearl oyster (Pteria sterna). The growth and survival results allowed, after 18 months of culture, the seeding of the animals to obtain two products: the “mabe” (half pearls) Western Society of Malacologists Annual Report Vol. 36, p. 40 and free pearls. The first product is the basis for the actual development of pearl oyster aquaculture in the bay. The second is of greater imporance because it advances implantation techniques and the skills needed for large-scale production techniques. The animals with the implants are cultured for at least two years to permit enough deposit of nacre over the artificial nucleus. The culture technique is still the original and it is particular to the Gulf of California. The technique consists on four stages: collection of juveniles, intermediate culture, grafting or nucleation, and culture. The most sensitive stage is the intermediate culture (60% survival). Nucleation activities show different results, 90% survival for “mabe” pearls and 31-35% of retention rate for free pearls (60% survival). The last stage of culture is a stable period with survival from 80 to 90%. The average time for the production takes 3 years for the “mabe” pearls and 4 years for the free pearls. The “mabe” are cut directly from the shells and prepared for their use in jewelry. The rest of the shells are used to manufacture mother of pearl buttons (for clothing). The powder from the shell is used to prepare lotions for therapeutic and cosmetic uses. The free pearls are classified and used directly for jewelry. Cultivo de concha nacar Pteria sterna en la Bahia de la Paz: Tradicion y modernidad El cultivo de la concha nacar Pteria sterna en la Bahia de La Paz fue muy reconocido a finales del siglo XIX debido, entre otros aspectos, a los avances tecnoldgicos empleados en esa epoca. Los productos principals eran la concha madre (para fabricacion de botones) y la perla natural. Sin embargo, conflictos sociales y la revolucion Mexicana de 1910 terminaron con esta actividad. Durante la segunda mitad del siglo XX, diferentes grupos de investigacion realizaron valiosos esfuerzos para iniciar nuevamente el cultivo de ostras perleras. Estos esfuerzos fueron recompensados en 1980, cuando se recuperaron los bancos naturales y se evaluo la factibilidad tecnica y economica del cultivo. El cultivo comercial en la Bahia de La Paz, se reinicio en 1999, a partir de la captacidn de semilla del medio natural. El desarrollo y la supervivencia obtenidos permitieron la obtencion de dos productos: el “mabe” (media perla) y la perla completa. El primer producto es la base del cultivo actual de ostras perleras en la Bahia. El segundo va cobrando mayor importancia, conforme se avanza en el dominio de la tecnica de implantacion y la capacitacion del personal para llegar a niveles de produccion a gran escala. Los animales con los implantes se cultivan por al menos dos anos para permitir suficiente deposito de nacar sobre los nucleos artificiales. La tecnologia de cultivo se divide en cuatro fases: recolecta de semilla, cultivo intermedio, implantacion de nucleos y cultivo. La fase mas delicada es la segunda, donde se obtiene una supervivencia del 60%. En la implantacion de nucleos se obtienen diferentes resultados, 90% de supervivencia de ostras con perlas mabe y 60% para ostras con perlas completas y un porcentaje de retencidn del 31 a 35%. La ultima fase de cultivo es la mas estable, con valores de supervivencia del 80 al 90%. El tiempo promedio para produccion de mabes es de 3 anos y de 4 anos para perlas completas. Las mabes se cortan directamente de las conchas y se preparan para su uso en joyeria. El resto de las conchas es usado para la fabricacidn de botones. La concha molida en polvo se utiliza para fabricacion de lociones terapeuticas y cosmeticas. Las perlas completas se clasifican y usan directamente para joyeria. Western Society of Malacologists Annual Report Vol. 36, p. 41 Evaluation of growth rate of Lyropecten (Nodipecten) subnodosus cultured in three different temperatures and fed with three bi-algal diets Nallely A. Ceron Ortiz', Beatriz Cordero Esquivel', Cecilia Flores Vergara', Patricia Asencio Padilla' and Miguel Robles Mungaray^ 'Departamento de Acuicultura Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE) Km. 107 Carretera Tijuana-Ensenada. A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail; aceron@cicese.mx ^Centro de Investigaciones Biologicas del Noroeste (CIBNOR) A.P. 128, La Paz, Baja California Sur, C.P. 23000 Mexico The culture of bivalves on a commercial scale has been developed for few species due to the lack of biological and ecological information on other bivalves with aquacultural potential. The commercial value of and aquacultural interest in the lion claw clam, Lyropecten {Nodipecten) subnodosus, has increased in the last years. However, there are some problems associated with its culture such as larval production and high seed mortality. The objective of this work was to evaluate the effect of temperature and type of diet on the growth of seeds of L. {N.) subnodosus. The culture of seeds was performed in a closed system for 10 weeks. Three temperatures (23, 26 and 29 ®C) and three bi-algal diets (Ml: Pavlova lutheri-Chaetoceros calcitrans; M2: Pavlova lutheri-Isochrysis sp. and M3: Isochrysis sp.- Chaetoceros calcitrans) were evaluated. Shell length and height were recorded weekly and organic dry weight was recorded every 2 weeks. The results of this work showed the effect of the diet on the growth of the organisms. The highest growth rate was found in organisms fed with the diet M3 independent of temperature. The shell length increase of the organisms was between 272 and 273% and the shell height increase was between 278 and 280%. The highest organic dry weight was found in organisms cultured at 26°C independent of the diet. Weight increase was between 2447 and 2955%. A mortality rate of over 50% was found after the second week of experimentation in organisms cultured at 29°C. Thus, survival of organisms cultured at this temperature was recorded up to the beginning of the third week. Evaluacion del crecimiento de Lyropecten {Nodipecten) subnodosus cultivada en tres diferentes temperaturas y alimentada con tres dietas bialgales El cultivo de moluscos bivalvos a nivel comercial se ha dirigido solamente a un numero pequeno de especies pertenecientes a este grupo, debido principalmente a la escasa informacion acerca de la biologia y ecologia de otras especies de bivalvos. La almeja mano de leon Lyropecten {Nodipecten) subnodosus es un bivalvo que en los ultimos anos ha incrementado su valor comercial y el interes de productores acuicolas para su cultivo, teniendo los principales problemas en la obtencion de larva y la alta mortalidad en la etapa de semilla. El objetivo del presente trabajo fue el de evaluar el efecto de la temperatura y la dieta en el crecimiento de L. {N.) subnodosus en etapa de semilla. Los cultivos de semillas se realizaron en un sistema cerrado durante 10 semanas, se evaluaron tres temperaturas (23, 26 y 29 °C) y tres dietas bialgales (Ml: Pavlova lutheri-Chaetoceros calcitrans’, M2: Pavlova lutheri-Isochrysis sp. y M3: Isochrysis sp.- Chaetoceros calcitrans), semanalmente se obtuvieron la longitud y ancho de la concha, y Western Society of Malacologists Annual Report Vol. 36, p. 42 quincenalmente el peso seco organico de los organismos. Los resultados obtenidos mostraron un efecto de la dieta en la longitud y ancho de las semillas, registrandose los valores mayores en los organismos alimentados con la dieta M3 independientemente de la temperatura, alcanzando un incremento entre el 272 y 273 % en longitud y de 278 a 280 % en el ancho de la concha. Con relacion al peso seco organico, se obtuvieron los mayores resultados en los organismos cultivados a 26 “C independientemente de la dieta, con incrementos entre el 2447 a 2955 % de su peso. Mortalidades de mas del 50 % de los organismos se registraron despues de la segunda semana en los cultivos mantenidos a 29 °C, por lo cual los resultados a esta temperatura se reportaron hasta el inicio de la tercera semana. Daily growth of early stages of sympatric mussels as criteria to differentiate colonization strategy Sergio Curiel Ramirez Gutierrez and Jorge Caceres Martinez Laboratorio de Biologia y Patologia de Organismos Acuaticos, Departamento de Acuicultura, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E- mail: scuriel@cicese.mx Substrate colonization by mussels may occur when larvae are competent to settle (250-470 mp) and reach optimal conditions for growth, or by post larvae when they are drifting in water column (500- 4000 pm) after settlement on a suboptimal substrate. Differentiation of the two strategies for colonization has ecological and practical significance, either for the same species or among different mussel species. To determine if a substrate is colonized by competent larvae or post larvae, it is necessary to know the maximum size of competent larvae after a determinate period of growth on the substrate. Larger mussels than expected after this period of time correspond to post larvae colonizing stages. In order to know the growth rate of early stages of coexisting Mytilus galloprovincialis and Mytilus californianus and take these values as reference to estimate the maximum growth on a substrate after a determinate period of time, early stages of both species were cultured in 1 L vessels at 18°C ± 1 and salinity of 35 ppt. Mussels were feed with 10ml of Isochrysis galbana (16 millions mf’) during a period of 20 days. Daily growth of M. californianus was 18.20 ± 0.80 pm and daily growth of M galloprovincialis was 33.70 ± 0.80 pm. Analysis of these different growth rates of both species showed that M galloprovincialis have a slower growth than M californianus, allowing their competitive exclusion from new substrates. This information also allows us to place collectors to obtain competent larvae or post-larvae for culture. Crecimiento diario de estadios tempranos de mejillones coexistentes para diferenciar su estrategia de colonizacion La colonizacion del substrato por parte de Mytilus spp. ocurre cuando la larva es competente (250-470 m_p) y alcanza condiciones optimas para establecerse y desarrollarse. Tambien puede ocurrir por post-larvas que se encuentran a la deriva en la columna de agua (500- 4000 _pm) despues de haberse fijado en un substrato suboptimo. La diferenciacion de ambas estrategias para Western Society of Malacologists Annual Report Vol. 36, p. 43 la colonizacion del substrate, tiene importancia ecologica y practica inter e intraespecificamente. Para determinar si un substrate en particular es celenizade per larvas cempetentes e pest-larvas, es necesarie cenecer la talla maxima que pedria alcanzar una larva cempetente sebre un sustrate despues de un periede de tiempe determinade. Les mejillenes que alcancen una talla mayer a la esperada, se habran asentade sebre el misme ceme pest-larvas. Para determinar el desarrelle diarie de estadies tempranes de Mytilus galloprovincialis y Mytilus californianus que habitan ceme especies simpatricas en la cesta del Pacifice de Baja Califernia y asi, tener las estimacienes de crecimiente necesarias para diferenciar la estrategia de asentamiente sebre un sustrate determinade, se celecaren estadies tempranes de ambas especies en recipientes de 1 L a 18®C ± 1 y salinidad de 35 ppm. Les mejillenes se alimentaren cen 10ml de Isochrysis galbana (16 millenes ml ') per un periede de 20 di'as. El crecimiente diarie de M californianus fue de 18.20 ± 0.80 _j:im mientras que el desarrelle diarie de M galloprovincialis fue de 33.70 ± 0.80 pm. El analisis de estas tasas de desarrelle para ambas especies nes die les valeres de referenda para diferenciar el asentamiente inter- e intraespecifice de larvas cempetentes y pest- larvas sebre un sustrate determinade. Per etre lade, se ebservo que Mytilus galloprovincialis muestra un crecimiente mas lente, le que puede centribuir a su desplazamiente per parte de Mytilus californianus durante la celenizacion de nueves sustrates. Las diferentes tasas de desarrelle tambien nes permiten utilizar sustrates para captar tante larvas cempetentes, ceme pest-larvas para ser usadas en cultive. Settlement of mytilids and its importance to mussel culture in Baja California, Mexico Sergio Curiel Ramirez Gutierrez and Jorge Caceres Martinez Laboratorio de Biologia y Patologia de Organismos Acuaticos. Departamento de Acuicultura, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada. A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E- mail: scuriel@cicese.mx Knowing the settlement season for mussels in a particular locality is important to determine when to place seed collectors for culture. Seed collection from nature is the most practical and economic method for mussel culture. This method is empirically used in Bahia de Todos Santos, Baja California; however, there is a lack of scientific information to support criteria to validate or improve this practice. Thus, the goal of this study was to use artificial collectors to determine the season and abundance of mytilid settlement in the culture area of the Bahia de Todos Santos and in a natural exposed mussel bed in Ejido Erendira. Collectors were nylon ropes (CN), polypropylene ropes (CP), cotton and polypropylene ropes (CAP) and synthetic commercial fiber (FS). Collectors were sampled monthly during 2 years, from December 1994 to November 1996. In the culture area collectors were placed at 2 and 5 meters depth. In Ejido Erendira they were placed in the middle intertidal zone. Collectors were transported individually to the lab, where mussels were detached, sized and counted. The season of settlement in Bahia de Todos Santos was autumn and winter in both years. However, abundance was different between years and collector type (10,164 in 1995 and 232,270 mussels in 1996). In Ejido Erendira the settlement season was winter and summer. Abundance was similar in 1995 and 1996, 44,141 and 53,166 mussels, respectively. The best collector determined by the density of spat was FS for both years and both localities. Differences in settlement season between localities could be related to the Western Society of Malacologists Annual Report Vol. 36, p. 44 species. Mytilus californianus is dominant in natural exposed mussel beds such as Ejido Erendira, and Mytilus galloprovincialis is dominant in protected localities such as Bahia de Todos Santos. These results suggest that artificial seed collectors could be placed during late autumn and early winter in Bahia de Todos Santos. In Ejido Erendira collectors could be placed from late autumn and early winter, and during summer. Fijacion de mitilidos y su importancia para el cultivo de mejillon en Baja California, Mexico El conocer la epoca de fijacion de una especie de mejillon en una localidad es importante para establecer cuando y en que zonas colocar los colectores de semillas para cultivo. La obtencion de semilla del medio natural es el metodo mas practico y economico para abastecer al cultivo. Este metodo se usa empiricamente en la Bahia de Todos Santos en Baja California; sin embargo, se carece de informacion cientifica que sustente o mejore la obtencion de semilla en colectores artificiales en la zona. For tal motivo, el objetivo del presente estudio fue determinar la estacion y abundancia de la fijacion de mejillones en la zona de cultivo de la Bahia de Todos Santos y en un banco natural de mejillon del Ejido Erendira usando diferentes colectores artificiales. Se utilizaron como colectores artificiales cuerdas de nailon (CN), de polipropileno (CP), algodon con polipropileno (CAP) y trozos de fibra sintetica comercial (FS), los cuales fueron reemplazados cada mes durante un periodo de dos anos, de diciembre de 1 994 a noviembre de 1996. Los colectores se colocaron en el area de cultivo a 2 y 5 m de profundidad y en el Ejido Erendira en la zona media del intermareal. Los colectores se transportaron individualmente en bolsas de polietileno al laboratorio, donde todos los mitilidos fijados fueron separados, medidos y contados. La fijacion de mitilidos en la Bahia de Todos Santos ocurrio a finales de otono y principios de inviemo en los dos anos estudiados; sin embargo, su abundancia fue diferente, en 1995 con 10 164 y 232 270 mejillones en 1996. Tambien se observaron diferencias en la abundancia de la fijacion por tipo de colector. En el Ejido Erendira la fijacion ocurrio en inviemo y verano en los dos anos estudiados. La abundancia de la fijacidn fiie similar, en 1995 con 44 141 y en 1996 con 53 166 mejillones. El colector que mostro mayor captacidn de semilla de mejillon fue FS en ambos anos de muestreo y en ambas localidades. Las diferencias en la temporalidad de la fijacidn entre localidades puede estar relacionada con la especie de mitilido; Mytilus californianus es dominante en las zonas naturales expuestas, como el caso del Ejido Erendira, mientras que Mytilus galloprovincialis es dominante en las bahias protegidas como en Bahia de Todos Santos. De acuerdo a los resultados obtenidos se recomienda colocar los colectores a finales del otono en la Bahia de Todos Santos y a principios de la primavera, mientras que en el Ejido Erendira es recomendable colocarlos a finales del otono y durante el verano. Western Society of Malacologists Annual Report Vol. 36, p. 45 Genetic advancements on cultured abalone in Baja Caliornia Miguel Angel del Rio Portilla’, Marisela Aguilar Juarez', Cristian Gallardo Escarate', Miroslava 1 2 Vivanco Aranda and Ana Li via Licona Chavez 'Departamento de Acuicultura, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Km. 107 Carretera Tijuana-Ensenada. A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail: midelrio@cicese.mx ‘Instituto de Investigaciones Oceanologicas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada. A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico Abalones, Haliotis spp., are an economic resource in Baja California. The fishery started at the beginning of the 20th century, but research on abalone genetics only started seven years ago. In this paper we present the genetic work done on cultured abalone in comparison with wild populations. Allozyme analysis has shown an adjustment to Hardy-Weinberg equilibrium in several abalone batches and there is an apparent relationship between heterozygosity and shell length. Furthermore, we will present a RAPD analysis of a recirculation-cultured abalone, along with karyotypic analysis and genome size of the abalone. Avances en la genetica del abulon cultivado en Baja California Los abulones, Haliotis, spp. tienen una gran importancia economica en Baja California, su pesqueria comenzo al inicio del siglo 20, pero los estudios geneticos apenas iniciaron hace siete anos. En este trabajo presentamos los estudios realizados en el abulon cultivado en comparacion con las poblaciones silvestres. Se ha encontrado, por medio del analisis alozimico, que existe un ajuste al modelo del Hardy-Weinberg en varios lotes y que existe una aparente correlacion entre el crecimiento de organismos y el grado de heterocigosidad. Asimismo se presentara el analisis genetico obtenido con RAPD en un sistema de recirculacion, el cariotipo y el tamano genomico del abulon cultivado. Growth and gametogenic cycle of the palmate oyster, Saccostrea palmula (Bivalvia: Ostreidae), in El Conchalito Estuary Esteban F. Felix Pico, Oscar E. Holguin Quinonez and Federico A. Garcia Dominguez Centro Interdisciplinario de Ciencias Marinas (CICIMAR-IPN). Avenida Instituto Politecnico Nacional S/N. Colonia Playa Palo de Santa Rita. A.P. 592. La Paz, Baja California Sur, C.P. 23096. Mexico. E-mail: efelix@ipn.mx Introduction The palmate oyster Saccostrea palmula (Carpenter, 1857) is an important commercial and subsistence resource in many estuaries along the Pacific coast from San Ignacio Lagoon, Mexico, and the Gulf of California, to Ecuador and the Galapagos islands, including Isla del Coco, Costa Rica (Skoglund, 2001). In Mexico, S. palmula occuring in mangrove swamps are Western Society of Malacologists Annual Report Vol. 36, p. 46 attached to roots of Rhizophora mangle and Laguncularia racemosa. This species also attaches to rocks, especially on reefs exposed to surf, in depths to 7 m. The genus Saccostrea is considered as a synonym of Crassostrea by Lawrence (1995). There have been several reports published on the reproductive cycle of this species, and it is recognized as a good candidate for culture because of its high fecundity and good growth rate, reaching commercial size (50- mm shell length in natural conditions) in one year. The present study was done to evaluate and standardize data and to describe the growth and the reproductive cycle of the S. palmula in the coastal waters of Bahia de La Paz. CICIMAR-IPN has been working with the park management plan's regulations of local fisheries and new activities. Materials and Methods Study area The lagoon of El Conchalito is a small mangrove forest (area 20 hectares) inside of the Ensenada de La Paz. It is on the Gulf of California coast of Baja California Sur in the southern part of Bahia de La Paz, between 24°07'-24°08' N and 1 10°20'-1 10°2T W. This narrow lagoon is separated from the sea by a straight sand bar about 0.5 km long. Tides in the lagoon are semidiurnal, with a maximum tidal range of 2.36 m, with strong tidal currents (31 cm. s''). The lagoon environment is hypersaline (36-42%o). Sampling, Measurements and Statistical Analysis The reproductive cycle was studied over a 17-month period. To determine the gametogenic cycle and growth, 30 oysters were collected monthly, measured for shell length and whole weight, and a gonadal sample was taken for histological analysis. Using standard histological techniques for analysis, each section of gonadal slide was sexed, and assigned to a development stage. A staging criteria of 1 to 5 was employed for undifferentiated (1), developing (2), ripe (3), spawning (4), and spent (5). For the a regression analysis was performed with the weight and the size. We tested sex ratios against a 1:1 ratio with Chi-square statistics. Results and Discussion Growth The oysters grow attached to prop roots of Rhizophora mangle 25 to 40 cm above sea level, in 2 the low intertidal zone. Within this habitat, S. palmula had an average density of 1.5 live ind/m , with maximum of 3 ind/m . In Magdalena Bay, Garda-Pamanes (1978) found densities between 0.5 to 947 live ind/m . Oysters grew from a mean size of 26.2 mm in October 1998 to 37.5 mm by October 1999-a rate of 0.9 mm per month (Fig. 1). Gametogenic cycle Of 287 oysters sectioned for histological examination, males dominated the population (43.9%) with only 13.2% females and 42.8% indeterminates. Gametogenic development was synchronous between males and females. Indeterminate oysters occurred in most months of the year. Gametogenesis, spawning and spent oysters occurred in the summer months (Fig. 2). In males, spawning and spent stages ranged from 37.6% of the oysters in September to 67% in October, with females in these stages ranged from 17% in August to 72% in October. The study population was dominated by large adults (20-45 mm shell length). The sex ratio of males and females were 3:1, and there was no evidence of hermaphroditism. The reproductive cycle Western Society of Malacologists Annual Report Vol. 36, p. 47 described here is similar to other palmate oyster populations occurring in northern Mexico (Cuevas y Martinez, 1978). Conclusions This species appeared to be slow-growing, averaging about 0.9 mm/month in length and of 0.16 g/month in wet weight. Population density is low. The estimated growth parameter K had a low value of 0.3 and 88.2 mm, with 4 years age. Indeterminate oysters occurried in most months, and reproductively active (with gametogenesis, and spawning and spent) oysters occurring at El Conchalito in summer months. Acknowledgements This work was funded by the Instituto Politecnico Nacional (Project CGPI-20031573), and the author received grants from SIDE (COFAA) and EDI. We also thank Viviana Aviles Ruelas (UniPaz) and Anel Ramirez Torres (UABCS) for technical assistance throughout the study. References Cuevas-Guevara, C.A. y A. Martinez-Guerrero. 1978. Estudio gonadico de Crassostrea corteziensis Hertlein, C. palmula Carpenter y C. iridescens Hanley, de San Bias, Nayarit, Mexico (Bivalvia; Ostreidae). An. Centro Cienc. del Mar y Limnol. Univ. Nal. Auton. Mexico 6(2); 81-98. Garcia Pamanes, L. E. 1978. Consideraciones sobre la biologia y ecologia del ostion de mangle (Crassostrea palmula y C. columbiensis) en el sistema lagunar de Bahia Magdalena, B.C.S., con referenda al rendimiento anual sostenible. Tesis Profesional, U.A.B.C., Ensenada, B.C., Mexico, 109 pp. Lawrence, D.R. 1995. Diagnosis of the genus Crassostrea (Bivalvia, Ostreidae). Malacologia 36(1-2): 185-202. Skoglund, C. 2001. Panamic province molluscan literature— Additions and changes from 1971 through 2000. I Bivalvia and II Polyplacophora. The Festivus 22: 129 y 20 pp. Western Society of Malacologists Annual Report Vol. 36, p. 48 Frequency (%) Fig. 1. Mean monthly shell length, +/- s.d. and isometric growth forS. palmula 1998 1999 2000 Fig. 2. Monthly percent frequencies of the reproductive phases for male and female palmate oysters in El Conchalito 100% 80% 60% 40% 20% □ Indeterminates aGametogenesis ^Mature ^ Spawn ■Spent Western Society of Malacologists Annual Report Vol. 36, p. 49 Desarrollo y cicio gametogenico del ostion palmeado, Saccostrea palmula (Bivalvia: Ostreidae), en el Estero El Conchalito El ostion palmeado Saccostrea palmula (Carpenter, 1857) es un recurso comercial y de subsistencia de gran importancia para las poblaciones de pequenos poblados que habitan a lo largo de la costa del Pacifico, desde la Laguna San Ignacio y el Golfo de California en Mexico hasta Ecuador y las islas Galapagos. El ostion se fija a las raices de los mangles y/o rocas, especialmente sobre arrecifes expuestos al oleaje y hasta profundidades de 7 m. Se han publicado varios registros sobre el cicio reproductivo de esta especie y se le reconoce como un buen candidate para cultivo debido a su gran fecundidad y tasa de crecimiento. En condiciones naturales alcanza la talla comercial en un ano, que es de unos 50 mm. El presente trabajo describe el desarrollo y cicio reproductivo de S. palmula en las aguas costeras de la Bahia de la Paz. El cicio reproductivo fue estudiado por un periodo de 17 meses. Para determinar el desarrollo y el cicio gametogenico de los ostiones, se recolectaron mensualmente 30 ejemplares. Se midio la longitud de la concha y se tomaron muestras de la gonada para analisis histologico. Los resultados mostraron que los ostiones se desarrollaron de una talla media de 26.2 mm en octubre de 1998 a 37.5 mm en octubre de 1999 (0.9 mm por mes). De 287 ostiones examinados, 43.9% fiieron machos, 42.8% se encontraron en estado indiferenciado y 13.2% fueron hembras. El desarrollo gametogenico entre hembras y machos fue sincronico. Se encontraron ejemplares en estadio indiferenciado durante todo el ano. En los meses de verano se observb la gametogenesis, desoves y estadios de reposo. El porcentaje de machos en estadio de desove y de reposo vario de 37.6% de ejemplares en septiembre, a 67% en octubre. En las hembras, estos estadios variaron de 17% en agosto a 72% en octubre. En la poblacion estudiada, hubo un predominio de adultos grandes (20-45 mm longitud de la concha). La proporcion de sexos entre machos y hembras file de 3:1 y no se encontraron hermafroditas. El cicio reproductivo descrito en este estudio, es similar al registrado en ostiones de otras localidades del Norte de Mexico. Aquaculture of abalone Haliotis spp. in Isla de Cedros, Baja California, Mexico Jose Guadalupe Gonzalez Aviles Sociedad Cooperativa de Produccion Pesquera “Pescadores Nacionales de Abulon”, S. C. de R. L. Ave. Ryerson 117, Zona Centro, Ensenada, Baja California, C.P. 22800 Mexico E- mail: jgonzale@cicese.mx Abalone aquaculture in Isla de Cedros started with purpose of recovering the natural abalone population, which had been exposed to an indiscriminate exploitation in the 1960’s. In that time, the production, fertilization and release of fertilized ova to the sea was named “seed tide,” a technique developed by Biol. Martin Ortiz Quintanilla. In the 1980’s abalones were transported to other areas with better conditions for growth, such as food availability, currents and protection. Moreover, the fishery in certain areas was closed to allow the recovery of abalone there. These areas remained closed for about 3 years, and then were opened to the fishery. In the early 1990's a small laboratory was built to produce abalone larvae and seed in order to restore the natural population and to respond to the authority’s request for this pupose. During that time. Western Society of Malacologists Annual Report Vol. 36, p. 50 an experimental abalone culture using 200 liter barrels in the sea was attempted. Results were favorable, allowing a promising technology for abalone aquaculture. In 2003 a project to develop this technology to commercial production is in evaluation. Acuicultura del abulon Haliotis spp. en Isla de Cedros, Baja California, Mexico La acuicultura del abulon en Isla de Cedros, se inicia con la fmalidad de restablecer los bancos abuloneros sometidos a una intensa pesca en la decada de los sesentas. A la produccion, fertilizacion y liberacion de huevos fertilizados en esa epoca se le denomino “mareas de cria”, tecnica atribuida al Biol Martin Ortiz Quintanilla. En la decada de los ochentas se realizaron trasplantes de organismos de una zona a otra con la fmalidad de colocarlos en mejores condiciones de alimentacion, refugio y corrientes marinas. Tambien se efectuo el cierre de bancos abuloneros a la captura comercial para restablecerlos. Estos bancos se abrieron nuevamente a la captura comercial, despues de mas de 3 anos. A principio de los noventa se construyo un pequeno laboratorio de produccion de larvas y semillas de abulon con la fmalidad de repoblar los bancos y dar cumplimento a las condiciones de la concesion de captura que preven el repoblamiento de los bancos abuloneros, mediante la siembra de larva competente y semilla producida en estas instalaciones. Tambien se realize un experimento de engorda de semilla de abulon producida en laboratorio en barriles de 200 litres con buenos resultados. Estos resultados han dado las bases para el desarrollo del maricultivo del abulon en la zona. En 2003 se presento un proyecto para ampliar el laboratorio con el fm de iniciar el cultivo comercial de abulon que se encuentra actualmente en evaluacion. Preliminary studies on the cryopreservation of red abalone {Haliotis rufescens) larvae Jessica Guadalupe Roman Espinoza and Carmen Guadalupe Paniagua Chavez 'pacultad de Medicina y Veterinaria Zootecnia Universidad Nacional Autonoma de Mexico Ciudad Universitaria, Del. Coyoacan, Mexico, D.F. 04510 Mexico E-mail: jessiquilla22@hotmail.com ^Departamento de Acuicultura Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada. A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico The culture of abalone in Baja California, Mexico, is a growing industry that requires supporting technologies. Cryopreservation of gametes or larvae offers several benefits. For example, sperm and larvae can be easily transported among hatcheries, selective breeding can be improved, stocks can be maintained and a resource of genes can be kept for advanced studies. The objectives of this work were to: 1) determine the acute toxic effect of three cryoprotectants and 2) assess the optimum freezing and thawing rates for trochophore larvae of red abalone. To determine the acute toxic effect, larvae were incubated in dimethylsulfoxide (DMSO), propilenglycol or glycerol, in three different concentrations (1%, 3% or 5%) for 5 or 10 min. Significant differences were found among the larvae maintained in the different cryoprotectants (P = 0.0002). No significant differences were found for larvae incubated in the concentrations of 3% and 5% (P=0.4630). Dimethylsulphoxide showed to be the less toxic in all the concentrations Western Society of Malacologists Annual Report Vol. 36, p. 51 and incubation times. The highest survival was found for larvae incubated in 3% DMSO at 10 min. Two experiments were performed to assess the optimum freezing and thawing rate. In the first experiment, larvae were incubated in 3% DMSO and 3% propilenglycol for 10 min. One thousand larvae per milliliter were placed in 0.5-mL straws, 5-mL macrotubes or 1.5-mL cryovials. After incubation, the samples were placed on a plastic screen in a Styrofoam box containing liquid nitrogen and were frozen at 1.5°C/min. from a temperature of 15°C to -35°C. The samples were held for 5 min and then plunged in liquid nitrogen. In the second experiment, the larvae were incubated in 5% DMSO or 5% propilenglycol for 10 min. One thousand larvae per milliliter were placed in 0.5-mL straws. After incubation, samples were frozen as experiment 1 to a freezing rate of 2.5°C/min. Two thawing temperatures were used; 45°C for 7 s, for 0.5-mL straws and 70°C for 5-mL macrotubes and 1.5-mL cryovials until ice crystals were not visible. No larvae survival was found after samples were thawed in either of the treatments. These results are the first attempt to freeze red abalone larvae in Mexico. Although we found the best cryoprotectant, we need more studies to determine the optimal freezing and thawing rates. However, these experiments are the beginning of new research on the cryopreservation of larvae of aquatic species of commercial and biological importance from Mexico. Estudios preeliminares sobre la criopreservacion de larvas de abulon rojo (Haliotis riifescens) El cultivo de abulon en Baja California, Mexico es una industria en desarrollo que requiere de apoyo tecnologico. La criopreservacion de gametos o larvas ofrece varios beneficios. For ejemplo, el esperma y las larvas pueden transportarse facilmente entre laboratorios, se puede mejorar la reproduccion selectiva, se pueden mantener reproductores y se puede mantener una fuente de genes para estudios avanzados. Los objetivos de este trabajo fueron: 1) determinar el efecto toxico agudo de 3 crioprotectantes y 2) valorar las tasas de congelacion y descongelacion para larvas trocoforas de abulon rojo. Para determinar el efecto toxico agudo, las larvas se incubaron en dimetilsulfoxido (DMSO), propilenglicol o glicerol, a 3 concentraciones (1%, 3% y 5%) por 5 o 10 min. Se encontraron diferencias significativas entre las larvas mantenidas en diferentes crioprotectantes (P = 0.0002). No se encontraron diferencias significativas entre las larvas incubadas a 3% y 5% (P=0.4630). El DMSO fue menos toxico a las concentraciones y tiempos de incubacion estudiados. La mejor supervivencia se encontro en las larvas incubadas a 3% DMSO por 10 min. Para determinar las tasas de congelacion y descongelacion se llevaron a cabo dos experimentos. En el primer experimento las larvas se incubaron a 3% DMSO y 3% propilenglicol por 10 min. Mil larvas por mililitro se colocaron en pajillas de 0.5-mL, 5-mL macrotubos o 1.5-mL crioviales. Despues de la incubacion, las muestras se colocaron en una malla en una caja de estireno con nitrogeno liquido y se congelaron a 1.5°C/min. de una temperatura de 15°C a -35°C. Las muestras se mantuvieron por 5 min. y se sumergieron en nitrogeno liquido. En el segundo experimento, las larvas se incubaron en 5% DMSO 6 5% propilenglicol por 10 min. Como en el caso anterior, se colocaron 1000 larvas por mL en pajillas de 0.5-mL. Despues de la incubacion las larvas se congelaron tal como se describio para el experimento 1, a una tasa de congelacion de 2.5°C/min. Se usaron dos temperaturas de descongelacion: 45°C for 7 s, para las pajillas de 0.5-mL y 70°C para macrotubos de 5-mL y crioviales de 1.5-mL hasta que no se observaron cristales de hielo. En ninguno de los tratamientos hubo supervivencia de larvas despues de que las muestras se descongelaron. Aun cuando encontramos el mejor crioprotectante, necesitamos mas estudios para determinar las tasas Western Society of Malacologists Annual Report Vol. 36, p. 52 de congelacion y descongelacion adecuadas. Estos experimentos constituyen el comienzo de la investigacion sobre criopreservacion de larvas de especies acuaticas de importancia biologica y comercial en Mexico. Culture of juvenile red abalones, Haliotis rufescens, in a recirculating water system Miroslava Vivanco Aranda and Miguel Angel del Rio Portilla Departamento de Acuicultura Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada. A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail: mvivanco@cicese.mx In Mexico, Baja California is the only state where abalone is cultured commercially. The most common culture system is a flow through system. Although some attempts to culture abalone using recirculation systems have been recently performed, no reports had been produced. The objective of this work was to evaluate the growth rate and survival of red abalone cultured in recirculation and flow through systems. The recirculation system consisted of a 250-liter fiberglass tank, biofiltration was provided by a 1 ft^ bubble washed bead filter. The flow through system consisted of a 250-liter tank with a daily water exchange rate of 800%. Constant aeration was provided throughout the experiment. Dissolved oxygen, temperature, pH and salinity were monitored daily. Total ammonia nitrogen (TAN), nitrate-nitrogen, nitrite-nitrogen and alkalinity were monitored three times weekly. Shell length was measured every two weeks for 18 weeks. All experiments were performed in triplicate. No significant differences in the temperature, dissolved oxygen, salinity, TAN, nitrate-nitrogen and nitrite-nitrogen and salinity were found. Alkalinity and pH were significantly different due to the addition of sodium bicarbonate. Abalone growth rates were 26.9±15.96 pm/day in the recirculation system and 23.28±18.69 pm/day in flow through system. Survival of juveniles was 78.7% for organisms in the recirculation system and 71.8% for organisms in the flow though system. Significant differences in final abalone size were found between systems (p<0.01). Therefore, recirculating systems are a feasible alternative for the culture of juvenile red abalone. Cultivo de juveniles de abulon rojo, Haliotis rufescens, en un sistema de recirculacion En Mexico, Baja California es el linico estado donde se cultiva el abulon bajo un sistema de cultivo abierto. A pesar de que se han hecho intentos para cultivar abulon en sistemas de recirculacion en la zona, no existen publicaciones sobre los resultados obtenidos. El objetivo de este trabajo fue evaluar la tasa de desarrollo y supervivencia de abulon rojo cultivado en un sistema de recirculacion y en un sistema abierto. El sistema de recirculacion estuvo compuesto por un estanque de fibra de vidrio de 250-1, la biofiltracion se realize por un filtro de cama de burbuja de 1 ft^. El flujo a traves del sistema file de una tasa de recambio de 800%. Durante todo el estudio se mantuvo aireacion constante. Diariamente se registraron los valores de oxigeno disuelto, temperatura, pH y salinidad. El amonio total (TAN), nitrato-nitrogeno, nitrito-nitrogeno Western Society of Malacologists Annual Report Vol. 36, p. 53 y alcalinidad se registraron dos veces por semana durante 18 semanas. Los experimentos se realizaron por triplicado. No hubo diferencias significativas en temperatura, oxigeno disuelto, salinidad, TAN, nitrato-nitrogeno y nitrito nitrogeno. La alcalinidad y el pH fueron diferentes debido a la adicion de bicarbonato de sodio. La tasa de desarrollo del abulon fue de 26.9±15.96 pm/dia en el sistema de recirculacion y de 23.28± 18.69 pm/dia en el sistema abierto. La supervivencia de los juveniles fue de 78.7% en el sistema de recirculacion y de 71.8% en los organismos mantenidos en sistema abierto. Las diferencias en crecimiento de los abulones en ambos sistemas fue significativa (p<0.01). Los sistemas de recirculacidn para cultivo de abulon representan una altemativa factible. V. GENERAL SESSION SESION GENERAL Organized by/ Organizado por Miguel Angel del Rio Portilla Departamento de Acuicultura, CICESE, Mexico Macrobenthonic molluscan thanatocoenoses in the Colorado River Delta area as a reflection of ecological changes Guillermo E. Avila Serrano , Karl W. Flessa and Miguel Agustin Tellez Duarte 'pacultad de Ciencias Marinas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada. A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico E-mail; gavial@uabc.mx ^Department of Geosciences, University of Arizona, Tucson, Arizona, USA The aim of this study was to evaluate the thanatocoenosis composition of shallow molluscan shelly fauna in the tidal flats of the Colorado delta. Ten transects and 1 12 stations were sampled in 1999 and 2000 (winter-summer) in five localities: 1) Campo Don Abel (north of San Felipe), in winter and summer; 2) Isla Vega, in winter; 3) Isla Sacatosa, in winter and summer; 4) Estero Chayo (Isla Montague), in winter; and 5) front of La Reserva de la Biosfera del Rio Colorado (north of Golfo de Santa Clara, Sonora), in winter. The localities 1 and 2 were named south zone, and localities 3 to 5 north zone. The fauna identified for all localities is composed of 122 species. Bivalves were the most abundant with densities from few to thousands of individuals per m^. The fauna was more abundant in the upper mesolitoral, and the taxonomic composition and abundance differs between the north and south zones. In general, the most abundant species were the bivalves Mulinia coloradoensis and Tellina meropsis. In the living fauna, M. coloradoensis is extremely scarce, which suggests that thanatocoenoses are paleoecological windows to understand ecological changes of the Colorado River delta attributed to the river’s water deflection. Western Society of Malacologists Annual Report Vol. 36, p. 54 Tanatocenosis de moluscos macrobentonicos en el area del Delta del Ri'o Colorado como un reflejo de cambios ecologicos El objetivo de este estudio fue evaluar la composicion de la tanatocenosis de la fauna de moluscos de aguas someras en las planicies mareales del delta del Rio Colorado. Se realizaron 10 transectos y se establecieron 112 estaciones que se muestrearon en 1999 y 2000 (invierno- verano) en cinco localidades; 1) Campo Don Abel (norte de San Felipe), en inviemo y verano; 2) Isla Vega, en inviemo; 3) Isla Sacatosa, en inviemo y verano; 4) Estero Chayo (Isla Montague), en inviemo; y 5) Reserva de la Biosfera del Rio Colorado (norte del Golfo de Santa Clara, Sonora), en inviemo. Las localidades 1 y 2 se denominaron zona sur, y las localidades 3 a 5 zona norte. La fauna identificada para todas las localidades esta compuesta por 122 especies. Los bivalvos fueron los mas abundantes con densidades de algunos cientos de individuos por m^. La fauna fue mas abundante en la zona alta del mesolitoral, y la composicion taxonomica y abundancia es diferente entre la zona norte y sur. En general, las especies mas abundantes fueron los bivalvos Mulinia coloradoensis y Tellina meropsis. En la fauna viviente, M coloradoensis es extremadamente escasa, lo cual sugiere que la tanatocenosis puede considerarse como ventana paleoecologica para entender los cambios ecologicos del delta del Rio Colorado atribuidos a la deflexion del agua del no. What happened to the bearded horse mussel at Bahia de los Angeles? (some after thoughts and possible microorganism identification) Wesley M. Farmer E-mail: wmfarmer@adnc.com While a guest of the Maricopa Community College Field Station at Bahia de los Angeles, and snorkeling along the rocky tidal area, the author noticed a die off of the bearded horse mussel {Modiolus capax) in its early stages. This was reported in The Festivus, 1990, and at WSM Asilomar, 1992. While employed at UCSD Medical Center, the author had an opportunity to make thin sections of tissues of Modiolus capax stained with Hematoxylin and Eosin, and with a special stain of PAS for carbohydrates. My search for a microbiologist to identify the causative organism of the die off was unsuccessful. The identification of the microorganism would confirm the reason for the die-off. A few mussels and interstitial bivalves were dying each day. The population of the mussel was devastated and the beaches deep in shells. Three well and three sick bivalves were secured for microscopic studies at the time. Some years ago these wet specimens were all transferred to Dr. Terrence M. Gosliner at the California Academy of Sciences, along with all my wet specimens of opisthobranchs. Chances are that the rocky habitat at Bahia de los Angeles might have another marine life die off. Knowing the name of the microorganism would help close this chapter for now. The samples will be sent to a pathology laboratory of aquatic organisms to identify the microorganism causing such mortalities. Western Society of Malacologists Annual Report Vol. 36, p. 55 ^Que ocurrio al mejillon caballo barbado en Bahia de los Angeles? (algunas reflexiones posteriores y posible identificacion de microorganismos) Mientras fui invitado de la estacion de campo del Maricopa Community College en Bahia de Los Angeles, buceaba a lo largo de la zona rocosa intermareal y observe gran numero de ejemplares muertos del mejillon caballo barbado Modiolus capax. Estas mortalidades ocurrian diariamente y afectaban a otros moluscos de la zona. La poblacion de mejillon fue devastada y las playas se llenaron de conchas vacias. Recolecte tres mejillones de apariencia saludable y tres aparentemente enfermos y los conserve. Estas observaciones las reporte en Festivus en 1990 y en la reunion de la WSM en Asilomar. Cuando trabaje en el UCSD Medical Center tuve la oportunidad de realizar algunos cortes histologicos de M. capax los cuales teni con hematoxilina- eosina, asi mismo utilice la tincion PAS para carbohidratos. Busque a un microbiologo para identificar al presunto organismo causal de aquellas mortalidades visto en los tejidos del molusco pero no obtuve ningun resultado. Hace algunos anos, envie mis especimenes junto con algunos opistobranquios al Dr. Terrence M. Gosliner de la Academia de California, quien me dio nuevas pistas sobre la posible identidad del microorganismo encontrado en los tejidos del mejillon. Es probable que en Bahia de Los Angeles ocurran otras mortalidades de fauna marina que pudiesen relacionarse con ese microorganismo. Por lo anterior es importante conocer su identidad y determinar si esta relacionado o no con dichas mortalidades. Hace unas semanas envie mis laminillas histologicas al Laboratorio de Biologia y Patologia de Organismos Marinos del CICESE para obtener mayor informacion al respecto. Notes on the knowledge of the freshwater mollusks of Mexico Edna Naranjo Garcia Departamento de Zoologia, Institute de Biologia Universidad Nacional Autonoma de Mexico, A.P. 70-153, Mexico, D. F. 04510 E-Mail; naranjo@servidor.unam.mx Advances in the ongoing project named “Catalogue of the non-marine mollusks of Mexico” are presented with emphasis on the freshwater pulmonates. The catalogue is based mainly in records gathered from the literature and observations from a collection owned by the author, which contains specimens from different regions of the country. The families recognized are: Lymnaeidae, Physidae, Planorbidae and Ancylidae. Three lymnaeid genera are recorded: Fossaria, Pseudosuccinea and Stagnicola. For the Physidae, Taylor’s new monograph recognizes seven genera for Mexico: Austrinauta, Amecanauta, Mexicanauta, Mayabina, Haitia, Chiapaphysa and Ultraphysella and has reduced several previously recognized species into only 15. For the Planorbidae, six genera are recorded: Gyraulus, Drepanotrema, Biomphalaria, Helisoma, Planorbella and Planorbula and for the Ancylidae, three genera: Ferrissia, Gundlachia and Hebetancylus. Many species of freshwater mollusks are distributed widely over the country but, in contrast, some species of Physidae and Planorbidae have narrow distribution patterns. These may be due to inadequate collecting. Thus, this study invites further surveys to confirm their endemism. For example, Planorbula has only been collected in the north (state of Tamaulipas) and south of the Gulf of Mexico (state of Quintana Roo). More studies are needed in these states to investigate its presence or absence over the extensive area in between. This may provide an explanation for its apparently discontinuous distribution. In addition, it seems that the Western Society of Malacologists Annual Report Vol. 36, p. 56 integrity of the native freshwater mollusk of Mexico is being threatened by the now invasive species Corhicula fliiminea and Melanoides tuberculata. These species have been recorded in numerous freshwater bodies across the entire country. Personal observations revealed that in some cases, native species are now restricted to certain parts of invaded areas, particularly when many Melanoides tuberculata dominate the habitat. Notas sobre el conocimiento de los moluscos de agua dulce de Mexico Se presentan avances del proyecto denominado “Catalogo de los moluscos no marinos de Mexico” con enfasis en los pulmonados de agua dulce. El catalogo se basa en registros obtenidos de la literatura y de observaciones de la coleccion propiedad del autor. Esta contiene especimenes de diferentes regiones del pais. Las familias reconocidas son: Lymnaeidae, Physidae, Planorbidae y Ancylidae. Se registran tres generos de lymnaeidos: Fossaria, Pseudosuccinea y Stagnicola. Para Physidae, la nueva monografia de Taylor reconoce 7 generos para Mexico: Austrinauta, Amecanauta, Mexicanauta, Mayabina, Haitia, Chiapaphysa y Ultraphysella y ha reducido a solo 15 las especies previamente reconocidas. Para Planorbidae, se han registrado 6 generos: Gyraulus, Drepanotrema, Biomphalaria, Helisoma, Planorbella y Planorbula y para Ancylidae, 3 generos: Ferrissia, Gundlachia y Hebetancylus. Muchas especies de moluscos de agua dulce se distribuyen ampliamente a lo largo del Pais pero, en contraste, algunas especies de Physidae y Planorbidae tienen estrechos patrones de distribucion. Esto puede deberse a recolectas inadecuadas. Asi, este estudio invita a realizar investigaciones para confirmar este endemismo. Por ejemplo, Planorbula se ha recolectado solamente en el norte (estado de Tamaulipas) y al sur del Golfo de Mexico (estado de Quintana Roo). Se necesitan mas estudios en esos estados para investigar sobre su presencia o ausencia sobre areas extensas y en zonas intermedias. Esto podria proveer de una explicacion a esta aparente distribucion discontinua. Ademas, parece que la integridad de moluscos nativos de agua dulce de Mexico esta siendo amenazada ahora por especies invasoras como Corbicula fluminea y Melanoides tuberculata. Estas especies se han registrado en numerosos cuerpos de agua dulce a lo largo de todo el Pais. Observaciones personales revelan que en algunos casos, las especies nativas estan ahora restringidas a ciertas partes de zonas invadidas, particularmente cuando muchas Melanoides tuberculata dominan el habitat. Western Society of Malacologists Annual Report Vol. 36, p. 57 Paleontology and geochronology of Pleistocene marine terrace faunas, Punta Banda, northwestern Baja California George L. Kennedy , Thomas K. Rockwell , Francisco Suarez Vidal , Daniel R. Muhs and John F. Wchmiller"* 'Department of Geological Sciences, San Diego State University San Diego, C A 92182 USA E-mail: gkennedy@bfsa-ca.com “Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada. A.P. 2732 Ensenada, Baja California, C.P. 22860. Mexico ^U. S. Geological Survey, MS 980, Federal Center, Denver, Colorado 80225 USA “^Department of Geology, University of Delaware, Newark, Delaware 19716 USA Twelve well-preserved, and additional less well-preserved, Pleistocene marine terraces are present on peninsular Punta Banda, a structural block bounded by two major faults, the Agua Blanca on the north and the Maximinos on the south. Fossil marine invertebrate faunas, however, are known only from the first, third, and fifth terraces. Based on amino acid racemization studies on bivalve mollusks, and uranium-series disequilibrium analyses of hydrocorals (Stylaster californicus) and solitary corals (Balanophyllia elegans), the lowest, “Lighthouse Terrace,” dates to about 80,000 years BP, correlative with marine oxygen isotope (6**0) substage 5a. The third, “Sea Cave Terrace,” dates to about 120,000 years BP, correlative with isotope substage 5e. The fifth terrace, based on altitudinal spacing of the lower terraces, is assigned an age of about 330,000 years BP, correlative with the sea-level highstand of isotope stage 9. Fossil marine invertebrate faunas, mainly mollusks, on the first, substage 5a, terrace contain several cool-water, extralimital northern species, whereas faunas from the third, substage 5e, terrace contain several warm-water, extralimital southern species on the protected northern side of the peninsula, but lack any extralimital species, southern or northern, on the southern side. Lfpwelling on the southern side of the peninsula may reduce surface water temperatures by as much as 8 °C compared to those on the protected northern side. Due to variable uplift rates and neotectonic activity, marine terrace faunas from the lowest emergent terrace at Alisitos-La Fonda, to the north, and from the second emergent terrace at Maximinos, to the south, correlate with those of the third, substage 5e terrace on Punta Banda. Paleontologia y geocronologia de la fauna de terrazas marinas del Pleistoceno en Punta Banda, noroeste de Baja California En Punta Banda, una placa estructural limitada por dos grandes fallas, la de Agua Blanca al norte y la de Maximinos al sur, se encuentran doce terrazas marinas del Pleistoceno bien preservadas y una pocas terrazas adicionales no bien preservadas. Sin embargo, la fauna fosil de invertebrados marinos se conoce unicamente en la primera, tercera y quinta terraza. Basandonos en estudios de racemizacion de aminoacidos en moluscos bivalvos y en analisis discontinuos en Western Society of Malacologists Annual Report Vol. 36, p. 58 series de mediciones de uranio de hidrocorales {Stylaster californicus) y corales solitarios (Balanophyllia elegans), la terraza mas baja “Lighthouse Terrace,” data de 80,000 anos BP, correlativo con el isotopo de oxigeno marino (6'^0) subetapa 5a. La tercera terraza “Sea Cave Terrace,” data de 120,000 ahos BP, correlativo con el isotopo subetapa 5e. La quinta terraza, de acuerdo con el espaciado altitudinal de las terrazas mas bajas, se le asigna una edad cercana a los 330,000 anos, correlacionado con el nivel del mar del isotopo de la etapa 9. Los fosiles de la fauna de invertebrados marines, principalmente moluscos, de la primera terraza subetapa 5a, contienen especies nortenas de aguas frias, mientras que la fauna de la tercera terraza subetapa 5e, contiene especies surenas de aguas calidas sobre el lado norteno protegido de la peninsula, pero carece de especies al norte y sur del lado sureno. Las surgencias sobre el lado sur de la peninsula pueden reducir la temperatura del agua superficial por mas de 8°C en comparacion con el lado norte. Debido a las tasas variables de levantamiento y a la actividad neotectonica, la fauna de las terrazas marinas mas bajas emergen en Alisitos-La Fonda, al norte y la segunda terraza emerge en Maximinos, al sur, que esta correlacionada con la tercera terraza, subetapa 5e de Punta Banda. Lipid composition and fatty acid profile related to spawning cycle of the queen conch Strombus gigas (Linnaeus) from the National Park of Arrecife de Alacranes, Yucatan Luis Alfonso Rodriguez Gil and Ake Canul S. Santos Institute Tecnologico de Merida, Av. Tecnologico Km. 4.5, Merida, Yucatan. Mexico E-mail: luisrdzgil@aol.com Tourism and high human consumption have contributed to the over-exploitation of natural populations of snails in the genus Strombus. These populations have fallen dramatically in Caribbean and Mexican waters since 1982. Due to overfishing and the increasing danger of extinction for these snails, the Mexican Government closed the Strombus fishery in 1987. Although fishing regulations is one method for population recovery, mariculture is an alternative to be evaluted. To be able to culture any of these species, it is necessary to know the relationship of the types and classes of lipids with the reproductive cycle of each species. This work determines the lipid composition and fatty acid profile during the reproductive cycle of the queen conch Strombus gigas (Linnaeus). The experiment was carried out for two years (2002- 2003) in the protected area of Arrecife de Alacranes. Extraction and separation of lipids was that used by Privett et al., and fatty acids were determined by gas mass chromatography. Different organs were sampled before, during and after spawning. Total lipid composition was determined during all three stages of the spawning cycle. The determination and quantification of the fatty acid profile measured the abundance of saturated, monosaturated and polyunsaturated fatty acids in relation with the numbers of eggs produced during spawning months. It was observed that the number of eggs decreased the saturated fatty acids and increased the unsaturated. It was determined that phospholipids represented the highest percentage of quantified lipids; this held true for all body organs studied. Before and during ovulation there is a greater quantity of saturated fatty acids, and less during ovulation. The monosaturated and polyunsaturated fatty acid levels are just the opposite during the beginning and final stages of spawning. These important data contribute an actual and definite way for CONAPESCA to legislate a closed season, based on scientific results. Likewise, this agency can give incentives for the fishery Western Society of Malacologists Annual Report Vol. 36, p. 59 sector to develop the mariculture of this species, corresponding to the exact timing of the spawning cycle, hence supporting the closed season. This project was carried out with teams of thesis, resident and Social Service students. Determinacion de la composicion de h'pidos y obtencion del perfil de acidos grasos con relacion al cicio de desove en el caracol marino Strombus gigas (Linnaeus) en el Parque Nacional de Arrecife de Alacranes, Yucatan El desarrollo del turismo y la alta demanda han contribuido a la sobreexplotacion de poblaciones naturales de las especies de caracoles del Genero Strombus, cuyas poblaciones han disminuido drasticamente en el Caribe y en Mexico desde 1982. Debido a la sobrepesca y ante el peligro creciente de la extincion del caracol, el Gobiemo Mexicano prohibio la pesca del caracol en 1987. A pesar de que la regulacion pesquera es uno de los medios para recuperar las poblaciones explotadas, la maricultura es una altemativa que debe evaluarse. Para lograr el cultivo de alguna de estas especies, es necesario conocer los tipos y clases de lipidos y la relacion que tienen con el cicio reproductivo de la especie. Por lo anterior, el proposito de este trabajo fue determinar la composicion de lipidos y obtener el perfil de los acidos grasos presentes en el caracol marino adulto Strombus gigas (Linnaeus) relacionado con su cicio de desove. La metodologia que se utilize para la extraccion y separacion en clases de lipidos fue la de Privett et al. y para determinar el perfil de los acidos grasos se uso la cromatografia de gases acoplado a un detector de masas. Los resultados comprenden muestras obtenidas durante 2002 y 2003. Se considero tomar muestras desde el inicio y hasta el final del periodo de desove. Se determino la composicion de lipidos totales en tres etapas del cicio del desove por organos. Se determino y cuantifico el perfil de acidos grasos en cuanto a la abundancia de acidos grasos saturados, monosaturados y poliinsaturados y se relaciono con el numero de puestas en los meses de desove observandose que al aumentar el numero de puestas disminuyen los acidos grasos saturados y aumentan los insaturados. Se determino y cuantifico la composicion de los lipidos presentes y se obtuvo el mayor porcentaje para los fosfolipidos. Se compararon las clases de lipidos por organos observando que el mayor porcentaje fue tambien para los fosfolipidos no importando el organo analizado. Se llego a la conclusion que antes y despues del desove hay una mayor cantidad de acidos grasos saturados y durante el desove disminuyen y sucede lo contrario con los monosaturados y poliinsaturados que durante el desove aumenta y al final disminuyen. Esta informacion obtenida es valiosa pues contribuye de una manera aplicada y defmitiva a las autoridades de la CONAPESCA para la implantacion del periodo de veda apoyado con estos resultados cientificos, mismos que daran incentivo al sector pesquero para el desarrollo de la maricultura de estas especies en relacion con el periodo exacto del cicio de desove que apoya al periodo de veda. Para la realizacion de este proyecto se formaron recursos humanos con tesistas y alumnos de residencia y servicio social. Western Society of Malacologists Annual Report Vol. 36, p. 60 Molluscan taphonomy and paleoecology at Mesa San Carlos, Baja California, Mexico 1 2 Miguel Agustin Tellez Duarte and Javier Helenes Escamilla 'pacultad de Ciencias Marinas, Universidad Autonoma de Baja California Km. 103 Carretera Tijuana-Ensenada, A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico E-mail; mtellez@uabc.mx “Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada. A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico The Paleocene molluscan fauna at Mesa San Carlos, Baja California, is diverse and characterized by an excepcional preservation state, which made it possible to evaluate thaphonomic processes involved during and before final burial and to diminish paleoecological bias. From 56 species identified only two were very abundant: Volutocorbis crassitesta (26.5%) ?ind Amauropsis martinezemis (16.8%). Less abundant but common were: Polinices pynionensis, Turritella penimularis qualyei, Cucullaea mathewsonii and Turritella reversa. Most species were rare and account for less than 2%. Taphonomic features such as fragmentation, abrasion and bioerosion were evaluated by ternary thaphograms. Results suggest that the shells remained a short time on the surface. A fast burial is also indicated by sedimentological characteristics which correspond to storm deposits or tempestites. From the later, the fossil assemblage could be classified as parautochthonous because it is composed of environmentally compatible organisms, disarticulated, transported, and concentrated within or very close to the original habitat. The dominance of V. crassitesta and Amauropsis martinezensis, species restricted to cold waters today, and the fact that 52 species of 28 overlap on distribution, suggest a warm climate, very similar to the adjacent ocean today. This indicates that there has not been considerable latitudinal displacement since the Paleocene, as has also been supported by micropaleontological evidence. Tafonomia y paleoecologia de Moluscos en la Mesa, San Carlos, Baja California, Mexico La fauna de moluscos del Paleoceno en la Mesa San Carlos, Baja California, es diversa y se caracteriza por un excepcional estado de conservacion, el cual hace posible evaluar el proceso tafonomico ocurrido durante y despues del enterramiento final y tambien hace posible disminuir el sesgo paleoecolbgico. De las 56 especies identificadas s61o 2 fueron muy abundantes: Volutocorbis crassitesta (26.5%) y Amauropsis martinezensis (16.8%). Menos abundantes pero communes fueron: Polinices pynionensis, Turritella peninsularis qualyei, Cucullaea mathewsonii y Turritella reversa. La mayoria de las otras especies fueron raras y representaron menos del 2%. Los caracteres tafonbmicos mas distintivos de las conchas como la fragmentacion, abrasibn y bioerosion se evaluaron por tafogramas temarios, sugiriendo que permanecieron un corto tiempo sobre la superficie y que el enterramiento fue rapido, tal como lo indicaron las caracteristicas de la sedimentacion, las cuales se corresponden con depbsitos de tormentas o tempestades. A partir de esta informacibn, el agrupamiento fbsil podria ser clasificado como para autbctono porque esta compuesto de organismos ambientalmente compatibles, desarticulados, transportados y concentrados dentro o muy cerca de su habitat original. La dominancia de V. crassitesta y Amauropsis martinezensis, restringidas a aguas fh'as actualmente y el hecho de que 28 especies de 52 se sobreponen en distribucibn, sugiere un clima calido, muy similar al del oceano adyacente hoy en dia. Esto indica que no ha ocurrido un Western Society of Malacologists Annual Report Vol. 36, p. 61 desplazamiento latitudinal considerable desde el Pleistoceno, tal y como ha sido concluido por la evidencia micropaleontologica. Genetic structure of the red octopus Octopus maya in the coasts of Yucatan 11 2 Jorge A. Tello Cetina , Jose B. Escamilla Sanchez and Andres M. Gongora Gomez 'institute Tecnologico de Merida, Av. Tecnologico Km. 4.5, Merida, Yucatan. Mexico E-mail 74080625@uxmal.itmerida.mx ^CIIDIR-Guasave. Carretera a Las Glorias Km. 1 .0, Guasave, Sinaloa, Mexico The genetic population structure of the red octopus Octopus maya from the Peninsula of Yucatan, Mexico was determined by expression of isoenzymes previously analyzed by polyacrilamide gel electrophoresis. Samples of mantle of 25 organisms from 3 different localities were used to characterize the genotypic expression from 24 loci in 30 enzymatic systems. The program Tools for Population Genetic Analyses (TFPGA) version 1 .3 was used to process data of genetic frequency of allozymes. We determine the parameters: descriptive statistics, F statistics. Genetic distances. Hardy- Weinberg equilibrium, UPGMA and number of migrants as indicator of gene flow. The heterozygosity range was 0.1010 for ME2 and 0.4978 for ESTl. The average heterozygosity was 0.0925. The average heterozygosity for Fis (0.2253) and for Fst (0.174) indicated a heterozygote deficiency. However, this heterozygosity is between the ranges reported for species of marine invertebrates. The number of migrants calculated from the equation of Slatkin was 2.4 per generation, which indicated certain grade of variability among the populations and is consistent with the low values found for Nei’s genetic distance, mainly, the lump that suggest the separation of the population of Rio Lagartos from the other populations (0.0066). We concluded that the population of Octopus maya has a certain grade of interpopulation genetic variability, which did not show the fragility of the subsistence of these populations. Estructura genetica del pulpo Octopus maya en las costas de Yucatan Se determino la estructura genetica poblacional del pulpo rojo Octopus maya en la Peninsula de Yucatan, Mexico, mediante la expresidn de isoenzimas en geles de poliacrilamida. Se utilizaron muestras del manto de 25 organismos, capturados en tres sitios de la Peninsula de Yucatan, para caracterizar la expresion genotipica revelada por la expresion de 24 loci en treinta sistemas enzimaticos. Se utilizo el programa Tools for Population Genetic Analyses versidn 1.3 (TFPGA) para procesar los datos de frecuencias genicas de aloenzimas de las poblaciones en estudio. Los parametros determinados ftieron: estadistica descriptiva, estadistica F, distancias geneticas, equilibrio de Hardy-Weinberg, UPGMA y el mimero de migrantes como indicador del flujo de genes. Los valores de heterocigosis, en un rango de 0.1010 para la ME 2 y de 0.4978 para la EST 1, con un valor de heterocigosis promedio de 0.0925, los de Fis un valor promedio de 0.2253 y los de Fst de 0.174 indican una deficiencia de heterocigotos pero que se encuentran dentro de los rangos registrados para especies de invertebrados marines. El mimero de migrantes derivado de la ecuacion de Slatkin resultd de 2.4 por generacion, lo que en forma global indica un cierto grade de variabilidad entre las poblaciones y es consistente con los bajos valores de Western Society of Malacologists Annual Report Vol. 36, p. 62 distancia genetica de Nei encontrados, particularmente el nodo que sugiere la separacion de la poblacion de Ri'o Lagartos de las otras poblaciones estudiadas, con un valor obtenido de 0.0066. Por los resultados de este estudio, se concluye que las poblaciones de Octopus maya presentan un cierto grado de variabilidad genetica interpoblacional que no refleja fragilidad en la subsistencia de estas poblaciones. On the diet of two octopod species found at California cold seep ecosystems Kent D. Trego Nautilus Oceanic Institute, La Jolla, CA 92037 USA E- mail; nautiIusoceanic@yahoo.com The octopod species Octopus califomicus (Berry, 1911) and Enteroctopus dofleini (Wulker, 1910) have recently been found in cold seep ecosystems off the California coast. This research addresses the possibility that these octopod species feed on cold seep bivalves. Octopus califomicus has been collected by trawl in cold seeps at 500 meters in the Santa Barbara Channel. The author examined trawl samples collected in 1997 and 1998 for evidence of octopus predation on cold seep bivalves. Specimens of the bivalve species Lucinoma aquizonatum (Steams, 1890) and Vesicomya elongata (Dali, 1916) were examined for the presence of octopus beak holes. There were no specimens found with evidence of predation by O. califomicus. Enteroctopus dofleini has recently been seen at cold seeps in Monterey Bay and off the Eel River in northern California. Specimens of the cold seep bivalve Vesicomya pacifica (Dali, 1891) collected at the Eel River cold seeps were examined for the presence of octopus beak holes. There were no specimens found with evidence of predation by E. dofleini. The diet of O. califomicus is not well understood. In captivity, O. califomicus responds positively to crabs, shrimp and small fish. However, O. califomicus shows no interest in clams, mussels and snails. The diet of E. dofleini has been well researched. The diet is very diverse and includes a variety of invertebrates and fish. Invertebrates in the diet of E. dofleini include bivalves, gastropods, brachiopods and echinoderms. The varied diet of E. dofleini implies that this octopus species will feed on a wide variety of obligatory and nonobligatory invertebrates and fish species at cold seeps. Dieta de dos especies de pulpo encontradas en ecosistemas de surgencia de agua fria en California Los pulpos Octopus califomicus (Berry, 191 1) y Enteroctopus dofleini (Wulker, 1910) se han encontrado recientemente en ecosistemas de surgencias de aguas frlas fuera de la Costa de California. Este resumen, senala la posibilidad de que esas especies de pulpos se alimenten de bivalvos de las zonas de surgencia de agua frla. Octopus califomicus ha sido recolectado con dragas a 500 metros en el canal de Santa Barbara. El autor examino las muestras de la draga recolectadas en 1997 y 1998 buscando evidencias de la depredacion de bivalvos de esas zonas por parte de los pulpos mencionados. Se examinaron las conchas de los bivalvos Lucinoma aquizonatum (Steams, 1890) y Vesicomya elongata (Dali, 1916) buscando perforaciones que indicaran la accion depredadora de los pulpos. No se encontraron espedmenes con tales evidencias de depredacion por parte de O. califomicus. Enteroctopus dofleini se ha visto Western Society of Malacologists Annual Report Vol. 36, p. 63 recientemente en los ecosistemas de surgencia de agua fria en la Bahia de Monterey y hacia fuera de Eel River al norte de California. Se revisaron especimenes del bivalvo de zonas de surgencia de agua fria, Vesicomya pacifica (Dali, 1891) recolectados en Eel River, en busqueda de evidencias de depredacion. Tampoco se encontraron especimenes con huellas de depredacion por E. dofleini. No se ha conocido con precision la dieta de O. californicus. En cautiverio, O. californicus se alimenta de cangrejos, camarones y pequenos pescados. Sin embargo, O. californicus no muestra interes cuando se le ofrecen como alimento almejas, mejillones y caracoles. La dieta de E. dofleini ha sido bien investigada. Esta es diversa e incluye una variedad de invertebrados y peces. Entre los invertebrados tenemos bivalvos, gasteropodos, braquiopodos y equinodermos. La diversa dieta de E. dofleini implica que esta especie de pulpo se podria alimentar con un amplia variedad de invertebrados y especies de peces de zonas de surgencia de agua fria. Abyssal mollusk notes Kent D. Trego Nautilus Oceanic Institute, La Jolla, CA 92037 USA E-mail nautilusoceanic@gmail.com Abyssal Station M Megafauna Mollusks The PULSE program under the direction of Dr. Ken Smith of the Marine Biology Research Division of the Scripps Institution of Oceanography has been involved with the long term monitoring of an abyssal ecosystem in the northeast Pacific off the coast of California since 1989. Abyssal Station M is located off the coast of Santa Barbara County 200 miles west of Point Conception (34°N 123° W). Otter trawl samples have been collected at depths of approximately 4100 meters. The following is a list of the mollusks collected at Station M: Bivalves: Bathyarca corpidenta, Bathyneara disa, Ciclopecten neoceanus, Ciispidaria glacialis, Cyclopecten squamiformis, Ennucula cardara, Kelliela galathae, Ledella ultima, Lima sp., Limopsis tenella, Malletia truncata, Nucula profundum, Propeamussium meridionale, Setigloma japonica, Solemya sp., Tindaria compressa, Xylophaga sp. Gastropods: Neverita lamonae, Streiraxis aulaca, Tenebrincola cukri. Scaphopods: Fissidentalium actiniophorum, Rhabdus rectius. Opistobranchs: Scaphander sp. Cephalopods: Opisthoteuthis sp. A Variation of the Hydrothermal Vent Bivalve Bathymodiolus thermophilus Kenk and Wilson, 1985 (Bivalvia: Mytilidae) In December of 1999, Dr. Horst Felbeck of the Marine Biology Research Division of the Scripps Institution of Oceanography collected an unusual specimen of Bathymodiolus while on an Alvin dive at the 9 North hydrothermal vents on the East Pacific Rise. The specimen was collected at 9°49.45750’N 104° 16.561 15’W at a depth of 2549 meters. The specimen is 1 1.4 cm in length and was deposited in the Scripps Institution of Oceanography Benthic Invertebrate Collection. The specimen was collected in an area inhabited by Bathymodiolus thermophilus and is the same general shape as B. thermophilus. The differences are the specimen collected is more elongated in shape, not being as inflated as B. thermophilus, and the periostracum is black. The periostracum for B. thermophilus is normally yellow to brown in color. Only one specimen of the unusual Bathymodiolus was found at the hydrothermal vents where it was collected. There is no Western Society of Malacologists Annual Report Vol. 36, p. 64 reason to believe the Bathymodiolus specimen is nothing more than an individual variation of B. thermophilus. The Solitary Abyssal Record for the Gastropod Bathybemhix bairJii (Dali, 1889) (Gastropoda; Trochidae) The gastropod Bathybembix bairdii (Dali, 1 889) is an eastern Pacific species occurring at a depth of 300-1500 meters from the Bering Sea, Alaska to Punta San Jose, Baja California. The only abyssal record of the species is a trawl sample from the Panama Basin (5° 9.8’N 81° 41.2’W) at a depth of 3900-4000 meters. The sample was collected by the research team of Dr. Ken Smith of the Marine Biology Research Division of the Scripps Institution of Oceanography on October 8, 1981. A total of nine specimens were collected and are in the Scripps Institution of Oceanography Benthic Invertebrate Collection and the Malacology Collection of the Los Angeles County Museum. This is a new depth record and a new southern range extension for the species. Herpes-like virus associated with eroded gills of the Japanese oyster Crassostrea gigas adults in Mexico Rebeca Vasquez Yeomans , Jorge Caceres Martinez and Antonio Figueras Huerta 'Laboratorio de Biologia y Patologia de Organismos Acuaticos, Departamento de Acuicultura, Centro de Investigacion Cienti'fica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail; rvasquez@cicese.mx ^Laboratorio Nacional de Referencia de Enfermedades de Moluscos del Instituto de Investigaciones Marinas de Vigo, Eduardo Cabello 6 - 36208, Vigo, Espana Since 1997, high mortality episodes among cultured oysters have occurred in Bahia Falsa, Baja California, Mexico. In the late 60’s, studies on the possible association of these mortalities with pathogens showed characteristics similar to those found in the Portuguese oyster Crassostrea angulata and the Japanese oyster Crassostrea gigas infected by an iridoviridae-like virus. This infection was named gill necroses virus infection (GNV). In a recent study using a transmission electron microscope (TEM) we could not find any virus in adult oysters with clinical and histological symptoms similar to those described for GNV. However, new TEM images showed the presence of viral particles in eroded gills of oysters. Morphological characteristics, such as thin-walled, icosahedric shape, the presence of capsids in an extension of the nucleus or in a vacuole and size varying from 80 to 90 nm suggest that the viruses belong to the Herpesviridae. This virus could be involved in the mortality episodes in the bay and it is different from those described as the causal agent of GNV. Virus tipo Herpes asociado con la erosion branquial en adultos del ostion Japones Crassostrea gigas en Mexico Western Society of Malacologists Annual Report Vol. 36, p. 65 Durante 1997, se presentaron mortalidades inusuales en el cultivo de ostion en Bahia Falsa, Baja California, Mexico. Estudios sobre la posible asocacion de estas mortalidades con patogenos mostro caracteristicas similares a las encontradas en el ostion Portugues Crassostrea angulata y el ostion Japones Crassostrea gigas infectado por un iridovirus hacia finales de los anos 60’s. A esta infeccion se le nombro Virus de la Necrosis Branquial (GNV, por sus siglas en ingles). En estudios recientes en ostiones adultos con sintomas clinicos e histologicos similares a los descritos a la GNV, y utilizando microscopia electronica de transmision (MET) no encontramos la presencia del iridovirus. Sin embargo, nuevas imagenes del MET mostraron la presencia de particulas virales en las branquias erosionadas del ostion. Las caracteristicas morfologicas que incluyen una pared delgada, la forma icosahedrica de la capside, la presencia de capsides en una extension del nucleo o en una vacuola y el tamano que varia entre 80 a 90 nm sugiere que estos virus estan relacionados con la familia Hesperviridae. Estos virus pueden estar asociados a los episodios de mortalidad presentes en la bahia y son diferentes de la descripcion del agente causal de la GNV. Identification isolated bacteria from gills of the Japanese oyster Crassostrea gigas cultured in Bahia Falsa, B. C., Mexico during a mortality episode Rebeca Vasquez Yeomans , Adrian Mauricio Garcia Ortega and Jorge Caceres Martinez 'Laboratorio de Biologia y Patologia de Organismos Acuaticos, Departamento de Acuicultura, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail; vasquezr@isa-ac.org.mx ^Laboratorio de Biologia Molecular, Comite Estatal de Sanidad Vegetal Km. 15 Carretera a San Felipe, Mexicali, Baja California, C.P. 21380 Mexico Since the late 1970’s, the Japanese oyster, Crassostrea gigas, has been cultured in Bahia Falsa, Baja California, Mexico. Nowadays, there are 21 companies involved in this activity. In 1997, unusual mortality episodes of oysters began to occur, reaching up to 80% of the production. These mortality episodes have been recurring up to the present, and the hypothesis that a pathogen such as a virus, bacteria or both is involved remains open. This work shows the results of a study on the physiological and biochemical characterization of isolated bacteria from gill tissue of oysters collected during a mortality episode in 2001. Three colonies were isolated. Two of them grew in TCBS selective medium, forming yellow colonies, which were identified as belonging to the genus Aeromonas. The third colony could not be cultured or identified. There are no records of the pathogenicity of Aeromonas spp. in mollusks; however, they have been reported as pathogenic for fishes and reptiles. Identification of the non-cultivable bacteria must be carried out by molecular methods. Identificacion de bacterias aisladas de las branquias del ostion Japones Crassostrea gigas cultivado en Bahia Falsa, Baja California, Mexico durante un episodio de mortalidad Desde finales de los anos 70’s, el ostion Japones, Crassostrea gigas, se ha cultivado en Bahia Falsa, Baja California, Mexico. Actualmente, existen 21 empresas dedicadas a esta actividad. Western Society of Malacologists Annual Report Vol. 36, p. 66 Durante 1997, se presentaron mortalidades inusuales en los cultivos de ostion, que alcanzaron mas del 80% de perdida en la produccion. Estos episodios de mortalidad siguen siendo recurrentes hasta la fecha y la hipotesis de que algun posible patogeno este involucrado, ya sea un virus, una bacteria o ambos, permanece vigente. En el presente trabajo se muestran los resultados de un estudio de caracterizacion fisiologica y bioquimica de bacterias aisladas de tejido branquial de ostiones recolectados durante un episodic de mortalidad en 2001. Se aislaron tres colonias. Dos de ellas crecieron en TCBS, formando colonias amarillas y que fueron identificadas como bacterias del genero Aeromonas. La tercera colonia no pudo ser identificada. Las bacterias identificadas del genero Aeromonas no se describen como patogenos en ostion, aunque si son patogenos de peces y reptiles. La identificacion de esta bacteria no cultivable por metodos convencionales debe llevarse a cabo por metodos moleculares. VI. POSTER SESSION SESION CARTELES Organized by/ Organizado por Beatriz Cordero Esquivel Departamento de Acuicultura, CICESE, Mexico Parasitic diagnosis of the eastern oyster Crassostrea virginica of Gulf of Mexico Ma. Leopoldina Aguirre Macedo, Raul Sima Alvarez, Karla Roman Magana y Jorge Giiemez Ricalde Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida Km. 6 Antigua Carretera a Progreso, A.P. 73 Cordemex, Merida, Yucatan, C.P. 97310 Mexico E-mail: leo@mda.cinvestav.mx The oyster Crassostrea virginica is an important resource in the Gulf of Mexico. This resource generates between 80 — 90 % of the national production of oysters. The purpose of this work was to determine the pathogenic agents that affect natural banks of oyster in the Gulf of Mexico, which have been overharvested in the last years. Sampling was performed in 10 coastal lagoons of the states of Veracruz, Tabasco and Campeche in dry and rainy seasons. Between 60 and 100 oysters were collected in each locality and were transported alive to the laboratory. Thirty oysters were examined for parasites while fresh (including the thioglycollate medium diagnosis of Perkinsus marinus), another 30 oysters were fixed and prepared for histological analysis, and between 10 and 15 oysters were used for microbiological diagnosis. With the exception of bacteria, the prevalence, mean intensity and abundance were calculated for each parasitic species per sample. Thirty-five species of bacteria were found, the most frequent belonging to the genera Pseudomona, Aeromona and Vibrio. Two protozoa {Perkinsus marinus and Nematopsis sp.) and three helminthes {Urastoma cyprinae, Proctoeces maculatus and Tylocephalum sp.) were also found. Prevalence and abundance values were highly variable among localities and among seasons, but usually low in most species. However, the highest prevalence was found in lagoons of the state of Tabasco. All the identified helminthes and protozoa were widely distributed in the Gulf of Mexico, and all of them are usually found in Western Society of Malacologists Annual Report Vol. 36, p. 67 oysters. Only Perkinsus marinus and Bucephalus sp. were associated with tissue damage to the hosts. Perkinsus marinus was considered the parasite with highest risk for the oyster banks due to their grade of pathogenicity and high prevalence (> 50% in most localities). Diagnostico parasitologico del ostion Crassostrea virginica del Golfo de Mexico El ostion Crassostrea virginica es un recurso pesquero muy importante en el Golfo de Mexico y genera entre el 80 al 90% de la produccion ostricola nacional. Con el fm de determinar la importancia de los agentes patogenos que afectan los bancos naturales y explotados de ostion en el Golfo de Mexico, se realizaron muestreos en 10 lagunas costeras en epoca de secas y Iluvias abarcando los estados de Veracruz, Tabasco y Campeche. Entre 60 y 100 ostiones fueron colectados en cada localidad y transportados vivos al laboratorio, donde 30 ostiones se procesaron para el diagnostico de parasitos en fresco, incluyendo el diagnbstico de Perkinsus marinus en medio de tioglicolato; 30 se fijaron y procesaron para realizar cortes histologicos y, entre 10 y 15 se utilizaron para el diagnostico microbiologico. Con excepcion de las bacterias, se calculo la prevalencia, intensidad media y abundancia media para cada especie de parasito por muestreo. El estudio revelo la presencia de un total de 35 especies de bacterias entre las que se encontraron mas frecuentemente especies de los generos Pseudomona, Aeromona y Vibrio', 2 protozoarios {Perkinsus marinus y Nematopsis sp.) y 3 helmintos (Urastoma cyprinae, Proctoeces maculatus y Tylocephalum sp.). Los valores de prevalencia y abundancia fueron muy variables de localidad en localidad y entre epocas, pero generalmente bajos en la mayoria de las especies. Sin embargo, los parasitos mostraron prevalencias mas altas en las lagunas de Tabasco. Todos los helmintos y protozoarios identificados estan ampliamente distribuidos en el Golfo de Mexico y son parasitos comunes del ostion. Solo dos especies, Perkinsus marinus y Bucephalus sp. estuvieron asociadas a danos en los tejidos de sus hospederos. Por su grado de patogenicidad y los altos valores de prevalencia (mas del 50% en la mayoria de las localidades) Perkinsus marinus se considera el parasito de mayor riesgo para los bancos estudiados. Genetic analysis of populations of the abalone (Haliotis spp.) using RAPD’s Marisela Aguilar Juarez and Miguel Angel del Rio Portilla Departamento de Acuicultura Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail: maguilar@cicese.mx The analysis of randomly amplified polymorphic DNA was applied to four Mexican species of abalone: Haliotis corrugata, Haliotis cracherodii, Haliotis fulgens and Haliotis rufescens and two Australian species Haliotis laevigata and Haliotis rubra using five commercial primers. We present the genetic relationships among Mexican and Australian abalone species in relation to allele frequencies, polymorphism, heterozygosity and genetic distances. Ninety-two polymorphic loci were found. The degree of polymorphism (95% criterion) was from 17% to 45%, and the heterozygosity was from 0.06 to 0.14. Genetic distances were between 0.03 and 0.97, but there was not a correspondence between the genetic and the geographical distance. Western Society of Malacologists Annual Report Vol. 36, p. 68 Analisis genetico de poblaclones de abulon (Haliotis spp.) mediante el uso de RAPD’s Se realize un analisis de ADN polimorfico amplificado al azar a cuatro especies de abulones mexicanos: Haliotis corrugata, Haliotis cracherodii, Haliotis fulgens y Haliotis nifescens y dos especies australianas Haliotis laevigata y Haliotis rubra utilizando 5 iniciadores comerciales. En este trabajo presentamos las relaciones geneticas entre especies de abulones mexicanos y australianos con relacion a las frecuencias alelicas, polimorflsmo, heterocigocidad y distancia genetica. Se encontraron 92 loci polimorficos. El grade de polimorfismo (criterio al 95%) fue de 17% a 45%, y la heterocigocidad fue de 0.06 a 0.14. La distancia genetica fue de entre 0.03 y 0.97, pero no hubo correspondencia entre la distancia genetica y geografica. En este trabajo se discute al respecto. Preliminary results in reproductive effort of Atrina maura in Laguna de San Ignacio BCS, Mexico Daniela Barrios Ruiz and Carlos Caceres Martinez Universidad Autonoma de Baja California Sur A.P. 19-B, La Paz, Baja California Sur, C.P. 23080 Mexico E-mail: dbarrios@uabcs.mx The fishery for the pen shell ("Callo de Hacha"), Atrina maura, along the peninsula of Baja California has increased in recent years. Studies on the development of this fishery are important to build future management plans. Pen shells are harvested in five zones of the peninsula, of which Laguna de San Ignacio (LSI), Baja California Sur, is one of the most important. Although there are many available qualitative studies describing the reproductive cycle in bivalve mollusks, there are few quantitative studies. This work addresses that issue. Starting in March 2002, seven individuals were sampled monthly in LSI. Height and length, total weight, shell weight, adductor muscle weight, and body weight were recorded. The total body volume and the volume of the valve cavity were also determined. The volumetric condition (IC) and muscle yield (IRM) indices were calculated. Transverse gonadal sections were made for standard histological analysis. The tissue slides were stained with hematoxilin — eosine, and photographed for analysis with Sigma Scan® software. Measurements and content analysis were used to determine ovocyte maturity. The lipids, carbohydrates and proteins in the gonad, digestive gland and muscle were analyzed to determine their relation with the gonadal cycle, which results are presented in this work Resultados preeliminares sobre el esfuerzo reproductive At Atrina maura en Laguna de San Ignacio Baja California Sur, Mexico La pesqueria del Callo de Hacha, Atrina maura en la Peninsula de Baja California ha aumentado en los liltimos anos. Por este motivo, los estudios sobre el desarrollo de dicha pesqueria son importantes para establecer futuros planes de manejo. La captura de Callo de Hacha se realiza en 5 zonas de Baja California, entre ellas, la Laguna de San Ignacio, Baja California Sur es una de las mas importantes. Existen diversos estudios que describen Western Society of Malacologists Annual Report Vol. 36, p. 69 cualitativamente el ciclo reproductivo de moluscos bivalvos; sin embargo, hay pocos trabajos cuantitativos sobre el esfuerzo reproductivo. En este trabajo se presentan algunos resultados sobre la biologia reproductiva de A. maura que brindan mayor informacion cuantitativa y cualitativa al respecto. Durante el afio 2002, se recolectaron mensualmente 7 ejemplares en la laguna de San Ignacio. Se registraron los siguientes datos morfometricos: altura y longitud total, peso total, peso de la concha, peso del musculo abductor y peso del cuerpo. Tambien se determino el volumen total del cuerpo y el volumen de la cavidad intervalvar. Se calcularon tanto el indice de condicion (IC) como el rendimiento del musculo (IRM). Se realizaron cortes transversales de la gonada para su analisis histologico convencional. La tincion usada fue hematoxilina-eosina y el tejido fue fotografiado para su analisis con el software de Sigma Scan®. Se realizaron las mediciones y conteos pertinentes de ovocitos para determinar su madurez. Se realizaron analisis de lipidos, carbohidratos y proteinas de la gonada, glandula digestiva y musculo para determinar su relacion con el ciclo gonadal. Los resultados de dichos analisis se presentan en este trabajo. Histopathological analysis of the native oyster Ostrea conchaphila (= O. lurida) in relation to mortality episodes of Japanese oyster Crassostrea gigas from Bahia Falsa, Baja California, Mexico Jorge Caceres Martinez, Yanet Guerrero Renteria, Rebeca Vasquez Yeomans, Sergio Curiel Ramirez Gutierrez and Patricia Macias Montes de Oca Laboratorio de Biologia y Patologia de Organismos Acuaticos, Departamento de Acuicultura, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E- mail: jcaceres@cicese.mx The native oyster Ostrea conchaphila is found naturally in Bahia Falsa, Baja California, where the Japanese oyster Crassostrea gigas was introduced in the middle seventies for culture. Since 1996, unusual mortalities of Japanese oysters have been occurring. One of the hypotheses to explain these mortalities is the presence of eroded gills and a pathogen, particularly a herpes- like virus recorded in the branchial tissue of some Japanese oysters. The question whether these erosions or virus are present in the native oyster is relevant to explain a possible transmission from one species to the other. A retrospective histopathological analysis of paraffin embebed samples of O. conchaphila taken between May 1996 and April 1997, when unusual mortalities of the Japanese oyster occurred, was carried out using routine histological procedures. Tissues were stained with hematoxilin and eosin-floxin and were observed using a transmitted light microscope. The results showed the presence of a Ancistrocoma-WkQ ciliated protozoan in a prevalence of 42.8% and mean intensity of 5.9 protozoa per infested oyster. In one organism a cyst of a metazoan was found in mantle and in two organisms, we detected hemocyte infiltration in tissue surrounding the digestive diverticuli, the epithelia of which were damaged. No evidences of gill erosion or viral inclusions in gills were found. The Ancistrocoma-\\\nQ protozoan was also found in the Japanese oyster sampled in 1996-1997, but it has not been related to mortality episodes anywhere. The absence of eroded gills and viral particles suggests that, if the hypothesis of a viral infection as cause of mortalities of C. gigas in Bahia Falsa is corroborated, the virus does not affect the native oyster. Western Society of Malacologists Annual Report Vol. 36, p. 70 Analisis histopatologico del ostion native Ostrea conchaphila (=0. lurida) en relacion con los episodios de mortalidad del ostion Japones Crassostrea gigas de Bahia Falsa, Baja California, Mexico El ostion nativo Ostrea conchaphila se encuentra naturalmente en Bahia Falsa, Baja California en donde se introdujo el ostion Japones Crassostrea gigas para cultivo a mediados de los anos 70. Desde 1996, se han presentado recurrentemente episodios inusuales de mortalidad del ostion Japones en la Bahia. Una de las hipotesis para explicar dichas mortalidades es la presencia de branquias erosionadas asociadas a un herpesvirus encontrado en el tejido branquial de algunos ostiones de la zona. La pregunta de si o no esas erosiones y/o virus se presentan en el ostion nativo, es importante para explicar un posible efecto de la transfaunacidn de especies. Para responder a dicha pregunta, se realizo un analisis histopatologico retrospectivo de muestras embebidas en parafma de O. conchaphila obtenidas entre mayo de 1996 y abril de 1997, cuando ocurrieron las primeras mortalidades masivas del ostion Japones en la Bahia. Para tal efecto se realizaron los procedimientos histologicos de rutina. Los tejidos se tineron con hematoxilina y eosina-floxina y se observaron usando un microscopio de luz transmitida. Los resultados mostraron la presencia del protozoo ciliado \\\)0-Ancistrocoma con una prevalencia del 42.8% y una intensidad media de 5.9 ciliados por ostidn. En un organismo se encontro un quiste de un metazoo en tejido del manto y en dos organismos se observaron hemocitos infiltrando los tejidos que rodean a los diverticulos digestivos, cuyos epitelios se observaron deformados. No se encontraron evidencias de erosion branquial o inclusiones virales en las branquias del ostidn nativo. El protozoo tipo Ancistrocoma, tambien se encontrd en el ostion Japones muestreado entre 1996 y 1997, pero, este organismo no se ha asociado con episodios de mortalidades masivas de ostion en ninguna localidad. La ausencia de branquias erosionadas y particulas virales sugiere que si se confirma la hipotesis de que una infeccion viral es la causa de las mortalidades masivas del ostion Japones, este virus no se encuentra en el ostion nativo. Parasitological and histopathological analysis of the ribbed mussel Geukensia {-Ischadium) demissa, from Estero de Punta Banda, Baja California, Mexico Jorge Caceres Martinez’’^, Jose Soledad Ibarra Rivera’ and Yanet Guerrero Renteria’ 'Laboratorio de Biologia y Patologia de Organismos Acuaticos, Departamento de Acuicultura. Centro de Investigacion Cientifica y de Educacidn Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail: jcaceres@cicese.mx ^Instituto de Sanidad Aculcola, A. C. Calle Novena y Gastelum 468 Local 14 Zona Centro, Ensenada, Baja California, C.P. 22800 Mexico The ribbed horse mussel Geukensia demissa was accidentally introduced into San Francisco Bay before 1890 and has spread along the California shore. A population of this species is now well established in the Estero de Punta Banda Baja California, Mexico. The origin of this species in the study area is unknown; presumably, it was introduced from California. Currently this Western Society of Malacologists Annual Report Vol. 36, p. 71 species is locally harvested for human consumption. There is not any information on the sanitary condition of this exotic mussel. The aim of this study was to carry out a survey of the parasitological load and histopathological condition of the species in the inner, middle and outer areas of the Estero. Mussels were analyzed fresh to determine presence of symbionts and the condition of the shell. Histopathological analysis of paraffin embedded samples was carried out using routine histological procedures. Tissues were stained with hematoxilin and eosin-floxin and observed using a transmitted light microscope. The parasitic copepod Pseudomyicola spinosus and an unidentified calanoid copepod were recorded crawling on the mantle, gills and labial palps of the host. Epibionts like Balanus sp. on the shell and some nematodes in the pallial fluid were recorded. At the histological level, different grades of hemocityc infiltration were found in the connective tissue of the mantle, gonads and digestive diverticuli, stomach and intestine. One cyst of an unidentified metazoan was found inside a reproductive follicle. Pseudomyicola spinosus was found occluding the lumina of the intestine. Differences in symbionts, parasites and tissue alterations are discussed in relation to the different ecological conditions in the sampled localities of the Estero de Punta Banda and parasites of bivalve mollusks previously recorded in the area. Analisis parasitologico e histopatologico del mejillon Geukensia (= Ischadium) demissa, del Estero de Punta Banda, Baja California, Mexico El mejillon Geukensia demissa fue introducido accidentalmente en la Bahia de San Francisco hacia 1890 y de ahi, se distribuyo a lo largo de la costa de California. Una poblacion de esta especie se ha establecido en el Estero de Punta Banda Baja California, Mexico. Se desconoce el origen de esta especie en dicho estero; probablemente, fue introducida desde California. Actualmente esta especie se recolecta localmente para consumo humano. No existe informacion sobre el estado sanitario de este mejillon exotico. El objetivo de este estudio fue llevar a cabo un analisis de la carga parasitaria y la condicion histopatologica de la especie en tres puntos del Estero de Punta Banda: zona externa, media e interior. Los mejillones se analizaron en fresco para determinar la condicion de la concha y simbiontes. El analisis histopatologico de los tejidos embebidos en parafina se realize siguiendo la rutina histologica. Los tejidos se tineron con hematoxilina y eosina-floxina y se observaron bajo el microscopio de luz transmitida. En el manto, branquias y palpos labiales se encontraron reptando, al copepodo parasite Pseudomyicola spinosus y a un copepodo calanoide. Sobre la concha se encontraron algunos balanos y nematodes en el fluido intervalvar. A nivel histopatologico se encontraron diferentes grades de infiltracion hemocitaria en tejido conectivo de los diverticulos digestives, intestine, estomago y gonada. Se encontro un quiste de un metazoo dentro de un foliculo reproductive. El copepodo Pseudomyicola spinosus se encontro obstruyendo el lumen del intestine y estomago, causando erosion de los epitelios de dichos organos. Se discute sobre los simbiontes, parasites y alteraciones histologicas encontradas en relacion con las condiciones ambientales de los puntos estudiados dentro del Estero. Tambien se analiza su relacion con los registros de carga parasitaria de los moluscos de la zona. Western Society of Malacologists Annual Report Vol. 36, p. 72 Terrestrial gastropods of south Nuevo Leon, Mexico Alfonso Correa Sandoval and Maria del Carmen Salazar Rodriguez Institute Tecnologico de Ciudad Victoria Blvd. Emilio Fortes Gil s/n. A.P. 175,Ciudad Victoria, Tamaulipas, C.P. 87010 Mexico E-mail: agutierr@uat.edu.mx Forty-three genera, 81 species and 14 subspecies of terrestrial gastropods belonging to 23 families are recorded for the southern area of the state of Nuevo Leon. Eighteen species and one subspecies are new records for the state. The families with with the highest number of species are; Spiraxidae (16), Urocoptidae (9), Pupillidae (8), Helicinidae (7) and Zonitidae (6). The species with the highest distribution per locality are: Gastrocopta pellucida (16), Pupisoma dioscoricola insigne (13), Punctum vitreum, Mesomphix montereyensis victoriana and Thysanophora hornii (11) and Guppya gundlachi (9). Seventy-four species (91.3%) of the terrestrial malacofauna are pulmonata and only 8.7% (7 species) are prosobranchia. From the area of study, only 34 (42%) are micro mollusks. This is the highest number found for any region in northeast Mexico. Gastrocopta ashmuni was recorded for the first time for this region. Considering the records from the north of the state of Nuevo Leon, 86 species are known for the state. Gastropodos terrestres del sur de Nuevo Leon, Mexico Cuarenta y tres generos, 81 especies y 14 subespecies de gasteropodos terrestres pertenecientes a 23 familias se registran para la region sur del estado de Nuevo Leon. Dieciocho especies y una subespecie son nuevos registros. Las familias con mas especies son Spiraxidae (16), Urocoptidae (9), Pupillidae (8), Helicinidae (7) y Zonitidae (6). Las especies con mayor distribucibn por localidades son Gastrocopta pellucida (16), Pupisoma dioscoricola insigne (13), Punctum vitreum, Mesomphix montereyensis victoriana y Thysanophora hornii (1 1) y Guppya gundlachi (9). El 91. 3% (74 especies) de la malacofauna terrestre es pulmonada y solo el 8.7% (7 especies) son prosobranquias. Del total de especies en el area de estudio 34 (42%) son micro moluscos. Este es el valor mas alto hallado para alguna regibn en el noreste de Mexico. Se indica a Gastrocopta ashmuni por primera vez para esta zona de la Repiiblica Mexicana. Tomando en cuenta los registros del norte del estado se conocen en total 86 especies para Nuevo Lebn. Distribution of “G” bands in the karyotype of Pomacea patula catemacensis Maria Esther Diupotex Chong, B. L. Montejo Quintero and M. Uribe Alcocer Universidad Nacional Autonoma de Mexico, Instituto de Ciencias del Mar y Limnologia A.P. 70-305, Mexico, D.F., C.P. 04510 Mexico E-mail; medc@icmyl.unam.mx The G bands in the karyotype of Pomacea patula catemacensis were studied and routine techniques were used to obtain trypsin-giemsa banding patterns in mitotic chromosomes of gonadal tissue cell. The results of this study may be useful in future research related to the Western Society of Malacologists Annual Report Vol. 36, p. 73 cytogenetics and cytotaxonomy of these freshwater snails, due to the agreement of the diploid number and gross morphology in the cytogenetics of the genus Pomacea. Distribudon de bandas “G” en el cariotipo de Pomacea patula catemacensis Se estudiaron las Bandas “G” en el cariotipo de Pomacea patula catemacensis. Se utilizaron tecnicas de rutina para obtener patrones de bandeo (tripsina-giemsa) en cromosomas mitoticos de celulas del tejido gonadal. Los resultados de este estudio pueden ser utilizados para futuras investigaciones relacionadas con la cito- taxonomia y/o sistematica debido al arreglo del numero cromosomico diploide y morfologia en la citogendica del genero Pomacea. Molecular characterization of Vibrio harveyi and its pathogenicity to postlarval Mytilus californianus Galdy Hernandez Zarate, Jorge Zamora Castro and Jorge Olmos Soto Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail: gaheman@cicese.mx A limiting factor for sustainable development of aquaculture is the presence of bacterial diseases in farmed organisms worldwide. Many members of the genus Vibrio have been implicated in these diseases, principally because these microorganisms are not only ubiquitous in the marine environment but they are also considered the principal bacterial group that form part of the normal flora of healthy marine organisms. Over the past decade, strains of Vibrio harveyi, have been recognized as significant pathogenic agents and a cause of high rates of mortality in many commercially cultured invertebrate species, such as oysters, shrimps and clams, principally in larval stages. Among the technologies used for diagnosis of V. harveyi in farms are biochemical tests and ELISA. While these methodologies are very useful, the techniques are time-consuming and can generate false-positive results. The development and sustainability of aquaculture urgently requires the rapid species-specific identification of V . harveyi for its effective control. Likewise, it is necessary to rely on technologies that would allow us to distinguish between virulent and avirulent strains of the bacterium. This study evaluated susceptibility of Mytilus californianus postlarvae to V. harveyi. Static bioassays in plastic container were carried out using concentration of 3.6 X 105 cfu ml-1. Postlarval survival was evaluated after 48 h. Also, we designed oligonucleotides targeting the genes txR, vhh-1, vhhB, luxL, luxM, luxN and developed a PCR methodology for the species-specific identification of V. harveyi. We also used the random amplified polymorphic DNA (RAPD) technique to characterize genetic differences between strains of V. harveyi and Vibrio spp. Preliminary results showed that postlarval Mytilus californianus were susceptible to V. harveyi. Mortalities of 80% were observed. Higher sizes of postlarvae seem to have less susceptibility to this bacterium. Primers for txR, vhhl, vhhB, LuxL and luxM were not specific for V. harveyi identification due to the amplification of genes of other Vibrio species. With regard to luxN primers, one product of the expected size (2048 bp) was amplified in the control strain, but not by the other Vibrio species and non-Vibrio spp. assessed. In addition, fifteen environmental isolates of Vibrio spp. Western Society of Malacologists Annual Report Vol. 36, p. 74 were tested and eight isolates had an amplified product of the same size. The RAPD analysis using OPS 11 primer, gave similar patterns between environmental isolates identified as V. harveyi and the control strain. This primer also discriminated between pathogenic and nonpathogenic strains of V. harveyi and allowed us to differentiate various Vibrio species. Our results indicated that V. harveyi is pathogenic for postlarval mussels. The PCR and RAPD-based methodologies allowed a rapid and accurate diagnostic assay for this bacterium, and thus it may be a helpful tool in the identification and differentiation of V. harveyi strains. Caracterizacion molecular de Vibrio harveyi y su patogenicidad hacia larvas de Mytilus californianus A nivel mundial, uno de los principales factores que limitan el desarrollo de la acuacultura, es la presencia de enfermedades bacterianas en organismos marinos cultivados. Diferentes especies del genero Vibrio han sido implicadas en estas enfermedades, principalmente debido a que estos microorganismos no son ubicuos solamente en el ambiente marino, sino que tambien son considerados como el principal grupo bacteriano que forma parte de la flora normal de organismos marinos saludables. Diferentes cepas de Vibrio harveyi, han sido reconocidas como patogenas y como causa de tasas altas de mortalidad en muchas especies de invertebrados cultivados, tales como ostiones, camarones y almejas, principalmente en sus estadios larvales. Entre las tecnologias utilizadas para la identificacion de V. harveyi en granjas de produccion acuicola, se encuentran las pruebas bioquimicas y el ELISA. Sin embargo, aiin y cuando estas metodologias son muy utiles, requieren tiempos prolongados para su realizacion, ademas de que pueden generar resultados falsos-positivos. El desarrollo y la sustentabilidad de la acuacultura requiere de una identificacion rapida de V. harveyi, para su control efectivo. Asimismo, es necesario utilizar tecnologias que nos permitan distinguir entre cepas virulentas y no virulentas de esta bacteria. Este estudio evaluo la susceptibilidad de postlarvas de Mytilus californianus ( 1 -4 mm) hacia V. harveyi. Se realizaron bioensayos en contenedores plasticos, utilizando una concentracion de 3.6 X 10^ ufc ml '. Se evaluo la sobrevivencia de las postlarvas a las 48 h. For otra parte, disenamos oligonucledtidos dirigidos a los genes txR, vhh-1, vhhB, luxL, luxM, luxN y desarrollamos una metodologia de PCR para la identificacion especie-especifica de V. harveyi. Tambien, se utiliz6 la tecnica del ADN Polimbrfico Amplificado al Azar (RAPD) para caracterizar las diferencias geneticas entre las cepas de V. harveyi y Vibrio spp. Resultados preliminares mostraron que postlarvas de M californianus fueron susceptibles a V. harveyi, observandose mortalidades del 80%. Las postlarvas de mayor tamano (3-4 mm) mostraron una menor susceptibilidad hacia esta bacteria. Los primers para txR, vhh-1, vhhB, LuxL y luxM no fueron especificos para la identificacidn de V. harveyi, debido a la amplificacion de genes de otras especies de Vibrio. Con respecto a los primers luxN, un producto del tamano esperado (2,048 pb) fue amplificado por la cepa control, no asi en otras especies de Vibrio, ni en los otros generos bacterianos evaluados. Ademas, 15 aislados ambientales de Vibrio spp. fiieron evaluados y ocho de estos mostraron un producto amplificado del mismo tamano. El analisis RAPD, utilizando el oligonucledtido OPS-1 1 mostrd patrones similares entre los aislados ambientales identificados Western Society of Malacologists Annual Report Vol. 36, p. 75 como V. harveyi y la cepa control. Este oligonucleotido tambien discrimino entre cepas patogenas y no patogenas de V. harveyi, permitiendo diferenciar varias especies de Vibrio. Los resultados indican que V. harveyi es patogeno para postlarvas de M californiamis. Las metodologias basadas en el PCR y RAPD, permitieron un diagnostico rapido y preciso de esta bacteria, por lo que estas tecnicas constituyen una herramienta util para la identificacion y diferenciacion de cepas de V. harveyi. Allometric analysis of juveniles of the red abalone, Haliotis rufescens., in a recirculating aquaculture system Marcela Enid Nunez Martinez', Jacob Alberto Valdivieso Ojeda' and Miguel Angel del Rio Portilla^ 'pacultad de Ciencias Marinas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada, A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico E-mail: marcelaenid@hotmail.com ^Departamento de Acuicultura Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico Recirculating aquaculture systems have started to be used in abalone culture. Alkalinity is one of the most important environmental variables to be considered. Nitrifying bacteria need bicarbonate and carbonate ions as a carbon source. Thus, nitrification reduces the amount of alkalinity in the recirculating system and reduces the buffering capacity of the seawater. Reduction in alkalinity can cause a drop in pH, and abalone shell may be dissolved to compensate carbonate consumption. In this work, we present an allometric analysis to compare the sizes of juvenile red abalone between a recirculating and a flow through culture systems as an evaluation of shell dilution due to pH reduction. Analisis alometrico de juveniles de abulon, Haliotis rufescens, en un sistema de recirculacion Los sistemas de recirculacion en acuacultura se han empezado a utilizar para el cultivo de abulon. La alcalinidad es una de las variables ambientales mas importantes ha considerar. Las bacterias nitrificantes requieren de iones carbonato y bicarbonato como fuente de carbono. De esta manera, la nitrificacion reduce la alcalinidad en los sistemas de recirculacion, asi como reduce la capacidad de amortiguamiento del sistema. La reduccion de alcalininidad puede causar la caida en el pH, y las conchas de abulon pueden comenzar a disolverse para compensar el consumo de carbonatos. En este trabajo presentamos un analisis alometrico para comparar las tallas de juveniles de abulon rojo entre un sistema de recirculacion y uno de flujo abierto como una evaluacion de la disolucion de la concha debido a la reduccion del pH. Western Society of Malacologists Annual Report Vol. 36, p. 76 Molluscs in coastal lagoons of Sonora and Sinaloa, Mexico: Habitat and habits Martha Reguero Meza Universidad Nacional Autonoma de Mexico, Instituto de Ciencias del Mar y Limnologia A.P. 70-305, Mexico, D.F., 04510 Mexico E-mail: reguero@icmyl.unam.mx Studies carried out in lagoon systems of the Mexican Pacific have provided data on species richness, feeding types and the sedimentary environment of benthic mollusks. These lagoons are Guaymas and Yavaros in the state of Sonora; Topolobampo and Caimanero-Huizache in the state of Sinaloa; and Agiabampo on the border between these two states. Sampling took place during the winter (February-March) and summer (August-September) of 1984 in areas that included different environments within each lagoon. Biological samples were collected with an otter trawl, and with a Van Veen grab sampler that obtained constant volumes of 1 liter of damp surface sediment, to insure collection of the highest possible number of species. We identified 265 mollusk species, of which 129 were Bivalvia, 130, Gastropoda and 6 Scaphopoda. Most of the bivalves were shallow infaunal detritivores and filter feeders, the scaphopods were infaunal detritivores, and the gastropods included numerous epifaunal carnivores. In the lagoons of Sonora, where communication with the sea is permanent, salinity is close to seawater and the substrate is predominantly sandy, whereas salinity fluctuates widely and the sediment is mainly silty clay in the lagoons of Sinaloa where seasonal inputs of freshwater are common. Moluscos de las lagunas costeras de Sonora y Sinaloa, Mexico: Habitat y habitos Los estudios que hemos realizado sobre moluscos bentonicos de sistemas lagunares del Pacifico Mexicano, nos han brindado datos sobre la riqueza de especies, tipos de alimentacion y el ambiente sedimentario. Esas lagunas son Guaymas y Yavaros en el Estado de Sonora; Topolobampo y Caimanero-Huizache en el estado de Sinaloa; y Agiabampo en la frontera entre esos dos estados. Los muestreos se realizaron durante el inviemo (febrero y marzo) y verano (agosto y septiembre) de 1984 en areas que incluyeron diferentes ambientes dentro de cada laguna. Las muestras biol6gicas se recolectaron con una “otter trawl”, y con un muestreador Van Veen que obtuvieron voliimenes constantes de 1 litro de sedimento, para asegurar la recolecta del mayor niimero posible de especies. Se reconocieron 265 especies de moluscos, de los cuales 129 corresponden a la clase Bivalvia, 130 a la clase Gasteropoda y 6 a la clase Escaphopoda. La mayoria de los bivalvos fueron detritivoros y filtroalimentadores, los escaphopodos fueron detritivoros y los gasteropodos incluyeron gran numero de especies cami'voras. En las lagunas de Sonora, la comunicacion con el mar es permanente, la salinidad es cercana a la marina y el sustrato es predominantemente arenoso, mientras que la salinidad fluctua ampliamente y el sedimento es principalmente limoso en las lagunas de Sinaloa, donde son comunes los aportes estacionales de agua dulce. Western Society of Malacologists Annual Report Vol. 36, p. 77 Prevalence of the parasite shaskyi (Gastropod: Eulimidae), and sublethal damage in Eucidaris galapagensis (Echinoidea) in the Galapagos Islands, Ecuador. J. 1. Sonnenholzner', L. B. Ladah^ and K. D. Lafferty^ ' Departamento de Ecologia Centro de Investigacion CientiTica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail: jorgeson@cicese.mx 2 Western Ecological Research Center, United States Geological Survey University of California, Santa Barbara, Santa Barbara, CA 93106 USA Introduction In the Galapagos Marine Reserve, Ecuador, the magnitude and severity of fishing pressure on lobsters and fish, and the lag time for these effects is unknown. If lightly-fished sites are compared to heavily fished sites (where urchin and crab predators, such as lobster and fish, are removed), we expect that the heavily fished sites to be more stressed with higher urchin abundance and higher infections by parasites. This hypothesis is strongly supported by the most fundamental principle of epidemiology, which says: parasite transmission strongly interacts with fisheries (Lafferty et al. 1999). Anderson and May (1981), reported that the prevalence of infections tends to increase with host population density. The aim of this study is to determine the patterns of prevalence of infection by the eulimid ectoparasitic gastropod Sabinella shaskyi, and to quantify the sublethal damage on the most conspicuous sea urchin, Eucidaris galapagensis (as host), around the center of the Galapagos archipelago. Material and Methods Twenty shallow sheltered rocky reefs sites, 10 lightly fished sites (LFs) and 10 heavy fished sites (HFs) were selected in the central region of the Galapagos Islands. Urchins and snails were measured with a sliding caliper, and urchin density was measured within a 10 m x 2 m belt transects (n = 30 per transect). Prevalence of infection was calculated by the number of urchins infected per number of urchins examined, and the sublethal damage was evaluated considering lesions on their spines. Standard deviations are shown in the graphs. Results Urchins and parasites were widely distributed around the center of the Galapagos archipelago. A total of 24,818 urchins were counted and 3,915 parasites, were collected. The highest densities of urchins were found in HFs. In spite of that, there was no significant difference in urchin density between HF vs. LF sites (ANOVA, p = 0.143). The maximum number of parasites on the same host was 63 (including both adult and juvenile parasites), and the maximum occurrence on a single spine was seven. The greater concentration of parasites (75%) was in LFs, but no significant difference was found in parasite concentration between HF vs. LF sites (ANOVA, p = 0.071). The prevalence of infection varied between 0% and 86%. The LFs showed significantly greater average values of prevalence of infection compared to the HFs (ANOVA, p < 0.001) (Fig. 1). Eighty-three percent of the urchins collected showed sublethal Western Society of Malacologists Annual Report Vol. 36, p. 78 lesions in their spines (galls and scars, associated to processes of erosion and inflammation of epidermis) (Fig. 1). Figure 1. Prevalence of infection and sublethal damage (galls) in the urchin spines from Eiicidaris galapagensis by the gastropod Sabinella shaskyi. The LF sites showed significantly greater average values of prevalence of infection compared to the HF sites in the Galapagos archipelago. As a regular pattern, parasites preferred to drill new spines. From all sea urchins collected, 42.6% had crabs on their spines. Crab prevalence was significantly greater in HFs (71.67%) versus LFs (15.78%) (ANOVA,/? < 0.00 J) (Fig. 2). Western Society of Malacologists Annual Report Vol. 36, p. 79 Figure 2. Brachyuran crab prevalence on the urchin spines {E. galapagensis). The HF sites showed significantly greater average values of prevalence of infection compared to the LF sites in the Galapagos archipelago. Discussion The high occurrence of parasites (Sabinella) in LFs was probably associated with a low density of parasite predators (e.g., brachyuran crabs associated to urchins) in LF sites. The results suggest three points; (1) A mediated effect due the high specificity of fisheries around the center of the Galapagos archipelago which causes fishing down marine food webs, that is, the predators of the sea urchins (e.g., lobsters and fish) are fished out, affecting sea urchin densities in HFs (Christensen & Pauly 1998, Pauly et al. 1999), (2) there exists a clear pattern in the distribution and abundance of the parasites and their predator, crabs and (3) in HFs, extraction of lobsters and fish (predators of the sea urchins and crabs, respectively), increase the densities of the sea urchins, but indirectly the occurrence of parasites decreases after the removal of the predators of the crab (e.g., fish). Therefore, the densities of the crabs increase and generate control in the number of parasites. Then, in contrast to the original hypothesis mentioned, a new conceptual model must be proposed to explain the biological interactions between fishing, urchin densities, parasites and snail predators (brachyuran crabs). Prevalencia del parasite Sabinella sharskyi (Gasteropodo: Eulimidae), y dano subletal en Eucidaris galapagensis (Echinoidea) en las Islas Galapagos, Ecuador El erizo marino mas conspicuo de las Islas Galapagos, Eucidaris galapagensis es parasitado por el gasteropodo Sabinella sharskyi (Eulimidae). Es la unica especie de equinodermo en el Western Society of Malacologists Annual Report Vol. 36, p. 80 Archipielago con el cual se asocia S. sharskyi. Este estudio fue llevado a cabo seleccionando 20 ambientes rocosos/arenosos de baja energi'a alrededor de las islas centrales del Archipielago Galapagos (Ecuador) en noviembre y diciembre de 2003, considerando 10 localidades de pesca intensa (Hf) y 10 de pesca escasa (Lf). Se conto un total de 3,914 caracoles y 24,818 erizos. Ambos se distribuyen ampliamente alrededor de todo el Archipielago Central. El 85% de los erizos de las localidades Lf estuvieron altamente infestados, mostrando un dano severo (perforados, erosionados y con galerias y cavemas) y espinas inflamadas. Dado que el caracol es un ectoparasito, se alimenta del mucus sobre el epitelio de las espinas del hospedero. La infestacion vario entre 0% y 90%, y el numero maximo de parasitos encontrados en un hospedero fue de 51 (adultos y nuevos reclutas) y 7 caracoles en la misma espina. Entre el 25% y 42% de las espinas del hospedero pueden estar danadas por los parasitos. Depredadores y parasitos interactuan como parte de los componentes del ecosistema, entonces definen el patron de ocurrencia de Sabinella. Las altas densidades de predadores de los parasitos (i.e., cangrejos) encontrados en las localidades Hf, y la densidad de E. galapagensis en las localidades Hf y Lf, podrian indicar que la pesca local artesanal en las Islas Galapagos (i.e., langostas y peces como predadores de erizos marinos) indirectamente favorecen las condiciones para los caracoles parasitos. Thermoregulatory study in pink abalone Haliotis corrugata Ana Denisse Re Araujo, Carlos Gerardo Re Araujo, Fernando Diaz Herrera and E. Zarina Medina Romo Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico E-mail: denisre@cicese.mx A physiological study of juvenile pink abalone Haliotis corrugata was done. The organisms used for experimentation were 25.7 ± 1.3 mm length and 18.5 ± 0.9 mm wide, and weighted 2.0 ± 0.35 g. Preferred temperature was obtained by putting the organisms in two different salinities (25%o and 35%o) using the gravitational method. The experiment was carried out in a horizontal thermal gradient divided in 15 segments with temperatures between 10.05 ± 0.5 8°C and 32.53 ± 1.04°C, constant aeration, and water flow rate between 130 and 150 ml/min. The preferred temperature was 25.0 ± 0.71 “C. No significant differences were found among the preferred temperatures by the juveniles acclimated in the salinities of 25%o and 35%o. The equation of Jobling (1981) was used to calculate the optimum temperature for growth, which was 24.5 °C. During the first hour of experimentation, the displacement velocity of the organisms acclimated in the two salinities had an interval from 48.89 to 50.9 cm/h. They displaced at 13 cm/hr during the day light phase. The velocity diminished (18.3 - 20 cm/hr) once the organisms were located around the preferred temperature. During the night phase, the displacement velocity was 10.1 cm/hr. These velocities were not significantly different (P>0.05). The maximum critical temperature (TCMax) was calculated according the methodology described by Diaz et al. (2000), which was 32°C at 50%. Western Society of Malacologists Annual Report Vol. 36, p. 81 Estudio de termoregulacion en abulon rosa Haliotis corrugata Se realize un estudio sobre termoregulacion en juveniles de abulon rosa. Los organismos utilizados en el estudio midieron 25.7 ± 1.3 mm de longitud y 18.5 ± 0.9 mm de ancho, y pesaron 2.0 ± 0.35 g. La temperatura preferencial se obtuvo colocando a los organismos a dos salinidades (25%o y 35%o) utilizando el metodo gravimetrico. El experimento se realizo en un gradiente termico horizontal dividido en 15 segmentos con temperaturas entre 10.05 ± 0.58"C y 32.53 ± 1.04°C, aereacion constante, y flujo de agua entre 130 y 150 ml/min. La temperatura preferida fue de 25.0 ± 0.71 °C. No se encontraron diferencias significativas de las temperaturas preferidas entre los juveniles mantenidos a las salinidades de 25%o y 35%o. Se utilize la ecuacion de Jobling (1981) para calcular la temperatura optima de desarrollo, la cual fue de 24.5 “C. Durante la primera bora de experimentacion, la velocidad de desplazamiento de los abulones aclimatados a las dos salinidades tuvo un intervalo de 48.89 a 50.9 cm/h. Durante la fase diurna, los organismos se desplazaron a una velocidad de 13 cm/h. La velocidad disminuyo (18.3 - 20 cm/h) una vez que los abulones llegaron alrededor de la temperatura preferida. Durante la fase nocturna, la velocidad de desplazamiento fue de 10.1 cm/h. Esas velocidades no fueron significativamente diferentes (P>0.05). La temperatura critica maxima (TCMax) fue calculada de acuerdo con la metodologia descrita por Diaz el al. (2000), la cual fue de 32°C al 50%. Community variations and growth of mollusks in modern carbonate environments along a latitudinal transect in the Gulf of California, Mexico Arturo Tripp Quezada Centro Interdisciplinario de Ciencias Marinas Departamento de Pesquerias y Biologia Marina Av. IPN s/n. Col. Palo de Santa Rita, Playa El Conchalito. A.P. 592 La Paz, Baja California Sur, C.P. 23060 Mexico E-mail: atripp@ipn.mx The Gulf of California displays a variety of transitional non-tropical carbonate environments in which mollusks are dominant producers. To gain a better understanding of the factors governing the formation and accumulation of these types of carbonates we are: 1) undertaking an analysis of the composition and structure of the benthic mollusks community, 2) determining the annual growth rates of dominant species, and 3) measuring time-series of environmental parameters in situ. Four localities were selected along a north-south transect from temperate to subtropical area, specifically, Bahia de los Angeles, Punta Chivato, Isla San Jose, and Cabo Pulmo. Preliminary results indicate that in the southern Gulf of California, Cabo Pulmo, macro mollusks are poorly represented. In San Jose, highest diversity of bivalve mollusks was found and contained the most important species: Megapitaria squalida, Glicymeris gigantea, Megapitaria aurantiaca and Dosinia ponderosa. In Punta Chivato, the species Chione californiensis was the most abundant and in Bahia de los Angeles, the scallop Euvola vogdesi dominated the community. Individual E. vogdsei 19.8 mm in size were collected in Bahia Juncalito Baja California Sur and transported to a culture area (extensive system). The organisms were cultured for 12 months and measurements were taken to determine the growth rate. We found a fast growth (mean shell height of 46.9 mm) through the summer and autumn. In Western Society of Malacologists Annual Report Vol. 36, p. 82 winter, the mean shell height reached 52.4 mm and shell weight was 41.4 g with a steady growth to summer. Variaciones de la comunidad y desarrollo de moluscos en ambientes modernos de carbonate a lo largo de un transecto latitudinal en el Golfo de California, Mexico El Golfo de California muestra una variedad de ambientes transicionales de carbonato no tropical en los cuales los moluscos son productores dominantes. Para entender mejor a los factores que gobieman la formacion y acumulacion de esos tipos de carbonato tenemos: 1) garantizar un analisis de la composicion y estructura de la comunidad de moluscos bentonicos, 2) determinar las tasas de desarrollo anual de las especies dominantes y 3) medir las series de tiempo de parametros ambientales in situ. Se seleccionaron 4 localidades a lo largo de un transecto norte-sur desde una zona templada hacia una subtropical, especiTicamente, Bahia de Los Angeles, Punta Chivato, Isla San Jose y Cabo Pulmo. Los resultados preeliminares indican que en el sur del Golfo de California, Cabo Pulmo, los macromoluscos estan pobremente representados. En Isla San Jose, se encontro la mayor diversidad de moluscos y las especies mas importantes: Megapitaria squalida, Glicymeris gigantea, Megapitaria aurantiaca y Dosinia ponderosa. En Punta Chivato, Chione californiensis fue la especie mas abundante y en Bahia de Los Angeles, la escalopa Euvola vogdesi fue la especie dominante en la comunidad. En Bahia Juncalito, Baja California Sur se recolectaron ejemplares de E. vogdesi de 19.8 mm y se transportaron a una area de cultivo (cultivo extensivo). Los organismos se cultivaron por 12 meses y se determino su tasa de desarrollo. Encontramos el maximo desarrollo (altura media de la concha de 46.9 mm) durante el verano y otono. En inviemo la altura media de la concha alcanzo 52.4 mm y el peso de la concha fue de 41.4 g. Durante el verano su desarrollo fue estable Mollusk community associated with the coral Pocillopora in Tenacatita, Jalisco, Mexico Cmthya Velarde Nuho , Luis Eduardo Calderon Aguilera , Dora Wauman and Ernesto Lopez Uriarte' ’CUCBA, Universidad de Guadalajara Carretera a Nogales Km. 15.5, Las Agujas, Nextipac, Jalisco E-mail: cvelarde@cicese.mx ^Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico ^Facultad de Ciencias Marinas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada, A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico To characterize the community of mollusks associated with the coral Pocillopora, four sampling surveys were conducted in November 2002, March, July and December 2003 at the shallow seashore of Tenacatita, Jalisco (19° 16’ 45” N - 104° 52’ 20” W). Pocillopora coral heads (20-30 cm diameter) were sampled using SCUBA and fixed in 10% formalin. Material Western Society of Malacologists Annual Report Vol. 36, p. 83 was fragmented and cryptic mollusks were sorted and preserved in 70% propanol. From 27 coral heads 331 specimens representing 36 species (24 gastropods and 12 bivalves) were collected. Lithophaga aristata and Quoyula monodonta were the most abundant species (90 specimens each). Thirty-eight specimens of Lithophaga plumula were found. Two bivalve species had 12 specimens each, and 1 1 species were represented by a single individual. On average, the mollusks were more abundant in March (18.9 individuals per coral head) and less abundant in December (5.1 individuals per coral head). Quoyula monodonta was found in 74% of the coral heads. Ovigerous females of this species were found in November 2002 and in July 2003. Lithophaga aristata was found in 55% and Lithophaga plumula in 44% of the 27 coral heads. Only one species was found in each of 1 8 samples. Thus, we could not estimate diversity indices or equitability and dominance indices. The graph of species richness shows that this sampling is reliable since the number of species found, so far, is very close to the maximum number of expected species. A Chi-square test showed that 18 species had an aggregated distribution. In addition, 18 species had a random distribution, but at a very different probability level. A cluster analysis (Bray-Curtis simple link) showed no significant groups among samples from the same survey nnor among samples from different surveys. Many empty shells, remarkably those from the gastropod Hipponix, were found in the samples, but it is not possible to know if they died in situ or if they were transported from somewhere else. Hermit crabs were also abundant. Identification of some species is still pending but the mollusk community can be considered fairly well described. Comunidad de moluscos asociados al coral Pocillopora en Tenacatita, Jalisco, Mexico Para caracterizar a la comunidad de las principales especies de moluscos asociados al coral Pocillopora, se realizaron 4 muestreos en noviembre de 2002, marzo, julio y diciembre de 2003 en la costa de Tenacatita, Jalisco (19° 16’ 45” N - 104° 52’ 20” O). Los corales Pocillopora (20- 30 cm. diametro) se muestrearon usando equipo de buceo autonomo y se fijaron en formalina al 10%. Se fragmento el material para obtener la criptofauna malacol6gica, misma que se preservb en alcohol al 70%. De los 27 corales recolectados se obtuvieron 331 especimenes de 36 especies diferentes (24 de gasteropodos y 12 especies de bivalvos). Lithophaga aristata y Quoyula monodonta fueron las especies mas abundantes (90 ejemplares de cada una). Se encontraron 38 almejas perforadoras, Lithophaga plumula. Se encontraron 12 ejemplares de cada una de 2 especies de bivalvos. Once especies estuvieron representadas por un solo ejemplar. En promedio, los moluscos fueron mas abundantes en marzo (18.9 ejemplares por coral) y menos abundantes en diciembre (5.1 ejemplares por coral). En el 74% de los corales se encontro a Quoyula monodonta. En noviembre de 2002 y julio de 2003, se encontraron hembras ovlgeras de esta especie. Las almejas perforadoras Lithophaga aristata y Lithophaga plumula se encontraron en un 55% y 44%, respectivamente de los corales estudiados. Los valores obtenidos no permitieron calcular los indices de diversidad y por lo tanto, tampoco la estimacion de la equitabilidad e indices de dominancia. En la grafica de riqueza de especies se confirme que el muestreo fue confiable dado que el mimero de especies encontradas fue muy cercano al numero de especies esperadas. La prueba de Chi-cuadrada demostro que 18 especies tuvieron una distribucibn de agregacion. Ademas, 18 especies tuvieron una distribucion aleatoria a un diferente nivel probabilistico. Un analisis de agrupacion (Bray-Curtis de enlace simple) mostro que no hubo diferencias significativas de grupos entre muestras del mismo muestreo y tampoco entre Western Society of Malacologists Annual Report Vol. 36, p. 84 muestras de muestreos diferentes. Tambien se encontraron muchas conchas vaci'as, en especial del gasteropodo Hipponix\ sin embargo, no es posible determinar si murieron in situ o si arribaron de algun otro lugar. Tambien se encontraron cangrejos ermitanos. Aunque la identificacion de algunas especies aun esta pendiente podemos decir que la comunidad de moluscos ha sido bien descrita. Use of microsatellite loci to evaluate the genetic variability in cultured juveniles of the Japanese oyster Crassostrea gigas Jacob Alberto Valdivieso Ojeda , Zaiil Garcia Esquivel and Miguel Angel del Rio Portilla 'pacultad de Ciencias Marinas, Universidad Autonoma de Baja California Km. 107 Carretera Tijuana-Ensenada, A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico E-mail: al307224@uabc.mx ^Instituto de Investigaciones Oceanologicas, Universidad Autonoma de Baja California Km. 106 Carretera Tijuana-Ensenada, A.P. 453 Ensenada, Baja California, C.P. 22860 Mexico ^Departamento de Acuicultura Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Km. 107 Carretera Tijuana-Ensenada, A.P. 2732 Ensenada, Baja California, C.P. 22860 Mexico The Pacific oyster, Crassostrea gigas, is one of the most widely cultivated mollusks in the world. The species is native to Japan, selected for its fast growth and its great adaptability to culture. In recent years, summer mortalities have been reported among oysters in San Quinti'n Bay, Baja California and one of the possible factors involved is a low heterozygosity level (indicated by allozyme loci). The objective of the current study is to use microsattelites to determine if there is a change in the heterozygosity and polymorphism. Uso de microsatelites para evaluar la variablidad genetica de juveniles de ostion Japones Crassostrea gigas de cultivo El ostion Japones, Crassostrea gigas, es uno de los moluscos mas ampliamente cultivados alrededor del mundo. Esta especie es originaria de Japon y se ha seleccionado para cultivo debido a su rapido desarrollo y adaptabilidad. En anos recientes, se han reportado episodios de mortalidad durante el verano en la Bahia de San Quintin, Baja California y uno de los posibles factores relacionados con estas mortalidades, es el bajo nivel de heterocigosidad (usando loci de alozimas). El presente estudio tiene como objetivo evaluar si hay algun cambio en la heterocigosidad y polimorfismo, usando microsatelites. Los avances obtenidos en este estudio seran presentados en este evento. Western Society of Malacologists Annual Report Vol. 36, p. 85 Taxonomic key for the identification of benthic opistobranchs in Mexican reefs 1 2 Andrea Zamora Silva and Martha Reguero Meza 'pacultad de Estudios Superiores Iztacala, UN AM Av. de los Barrios #1, Col. Los Reyes Iztacala Tlalnepantla, Estado de Mexico, C.P. 54090 Mexico E-mail; bazs0201@correo.unam.mx " Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico A.P. 70-305, Mexico, D.F., C.P. 04510 Mexico Only few studies have been published about the bubble shells and snails of the subclass Opistobranchia for Mexico. Isolated studies indicate that these species are found in coral reefs located at the Pacific Ocean, Gulf of Mexico, Yucatan Peninsula and Caribbean. Nevertheless, bibliographical sources that provide information about systematic, species richness and distribution, as well as taxonomic keys for the identification of these mollusks, are needed. From this perspective and as a contribution to the knowledge of the benthic opistobranchs of coral reefs in Mexico, a useful taxonomic key to identify and to make revisions the classification of these species has been produced. The taxonomic key includes the families and generic taxa, a glossary of malacological terms and some data about the biology of these organisms. Claves taxonomicas para la identificacion de opistobranquios en arrecifes Mexicano Pocos trabajos se han publicado sobre los caracoles burbuja y los moluscos de la subclase Opistobranchia de Mexico. Estudios aislados indican que esas especies se encuentran en los arrecifes de coral del Oceano Pacifico, Golfo de Mexico, Peninsula de Yucatan y mar Caribe. Sin embargo, se requieren estudios que brinden informacion sobre sistematica, riqueza de especies, distribucion y tambien de claves taxonomicas para su identificacion. Desde esta perspectiva y como una contribucion al conocimiento de los opistobranquios bentonicos de los arrecifes de coral de Mexico, se elaboro una clave taxonomica y un ajuste en la clasificacion de dichas especies. La clave taxonomica incluye las familias y taxones genericos, un glosario de terminos malacologicos y algunos datos sobre la biologia de dichos organismos. Western Society of Malacologists Annual Report Vol. 36, p. 86 VII. REPORTS OF SOCIETY BUSINESS 1. Student Grant Committee, 2004 Doug Eemisee, Daniel Geiger, Lindsey Groves (Chair), Sandra Millen, and Peter Roopnarine Recipients of the 2004 WSM Student Grant Awards: Claire-Louise Martin, National Marine Science Centre, Coffs Harbour, Australia. "Testing the assumed constraints of a symmetrical mantle cavity on increasing body size in fissurellid gastropods" ($800). Jann Vendetti, University of California, Museum of Paleontology, Berkeley, CA. "Shell character evolution in the extinct Cenozoic gastropod genus Bruclarkia" ($500). Kenneth Hayes, University of Hawai‘i, Manoa, Honolulu, HI. "Systematics, phylogeography, and evolution of South American apple snails (Pomacea)" ($300). Executive Board Meeting, Minutes Annual Business Meeting Minutes, and Treasurer’s Report are not available.- The Editor Annual Report Vol.^,^C p. 87 Western Society of Malacologists • u»»r •,T' •’ AficIrtR Slips’ M _ . - V ^,*1 ,0-»mM tnbtinz .^’iwfma »noa ^ ' a*Iivti.i*»fU, fe»tr*dto de M6.*co ftnnatiqoo^. 'ff , ai «.i« vbo.1 sni«=n»i» Mmwj bnmvm> »* a‘n»»r -; ,(»'02) "«bo(10TJar4 birtfiw A (^i»4Bco'ii'>ia(Oiai;*>'!*«<><*>«4'Voi«iinfeii»i*i»viw^ *w«»an«w, ■. "it.l'*i» fo ffi»k« fC' tlK. »i. (f r»Wi;.v:olojpO<4 ICITTVA iHnnS r* : ..^V' ^ ( lives f<>auftAmld» iV M>. sljruaicf^ ii^ l^vxir»r»o I'TK'o** »r j»»'» • 'iii bm f n. hi ’ nbcliw imuirt^vxwlym.dn W.:Arx^ tlwtiart fit r ^ mcvlfc" -bc^ir.^ A:! Ckf ino J>asJt/Jc4i, uOlXo MfeOw*. ‘it' Yut-i.'W y uM.QiBtm. m ar.binjo. - I'k mi^mnifuki ttahfc^i.a Uic^i 4:^41^ 4' li: 4**-; s.UVl^V - '’'2? ’ ' Vi ,vx.iuo u ■ '■T4^ ■ 'W V •'*1 • , ^ I «l -^4 «• Jt M ■ V e 'i»' ■ ■y;-.VY ■: . ■■ * , :t ■■ .■‘■^ ■ • & >« [0 «&L« Ilf