ABSTRACTS IN ALPHABETICAL ORDER OF AUTHOR

Endocrine disruption in vertebrates such as fresh water fish has been widely reported in the UK and across the world in rivers impacted by industrial and domestic sewage effluents. A range of substances from natural steroid oestrogens to chemicals found in surfactants and plastics have been shown in laboratory experiments to disrupt reproduction and in some cases completely feminise male fish. Molluscs are known to be sensitive to endocrine disruption by the organotins used in antifouling boat paint; changes to the female gonad and sexual morphology have been recorded.

The aim of this work is to establish whether native gastropods are affected by the Endocrine Disrupting Chemicals (EDCs) found in UK effluents and Rivers.

Adult snails were dosed during their reproductive period (i.e. spring/summer) and first generation (F1) juvenile snails were dosed developmentally in a river water mesocosm. Morphological, histological and reproductive endpoints were all measured.

Project funded by DEFRA and the Environment Agency

Cytogenetic comparison of the freshwater snails Viviparus ater and Viviparus contectus (Gastropoda: Prosobranchia)

BARBARA BECK-WOERNER

Zoological Museum, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.

b.beck-woerner@bluewin.ch

Chromosomal rearrangements play a role in the majority of speciation events. Certainly they contribute to reproductive isolation. Reproductive isolation may be due to different chromosomal numbers because matings between species with different chromosomal numbers are almost always sterile. The two species V. ater and V. contectus are amazing in so far as they have different chromosome numbers but can hybridize and produce fertile offspring in nature. The aim of my project is to find out whether some chromosomal rearrangements took place during the evolution of V. ater and V. contectus. I will do a cytogenetic comparison by building a karyogram (systemised array of the chromosomes) and an idiogram (diagrammatic representation of a karyotype) by means of banding techniques. [Poster]

Limicolaria martensiana revisited: an ecological study in the Ssesse Islands, Uganda

WILLIAM BENSON

20 Holyrood Avenue, Southampton, Hampshire, SO17 1SH, UK.

wdb105@soton.ac.uk

We report on a 2007 expedition to study the ecological genetics of the polymorphic achatinid land snail Limicolaria artensiana, some 40 years after the subject was last investigated by the late D.F. Owen. Our method was to sample 22 populations on the islands of the Ssesse archipelago in the Ugandan waters of Lake Victoria, East Africa, and for each population we estimated morph frequency together with several other shell and ecological variables. We will present our preliminary findings on the basic ecology of L. martensiana and the factors that may be affecting the frequencies of its different morphs. Morphs of L. martensiana: dark and light streaked and some pallid forms.

Genetic variation in the mud snail, Hydrobia ulvæ

ROBERT J. BROWNLOW & J. D. FISH

University of Wales, Aberystwyth.

rjb00@aber.ac.uk

The mud snail, Hydrobia ulvæ, is one of the most abundant inhabitants of estuaries in Western Europe. The presence of a pelagic larval stage in the life-cycle suggests that closely linked populations should be well mixed and thus approaching a panmictic state. However, populations of Hydrobia in the Dyfi estuary show significant levels of morphological variation, and sampling of successive cohorts of larvae suggest self recruitment and possible genetic variation. Isolation of microsatellite sequences and development of novel primers has enabled comparison of snails from an ecological series in the Dyfi estuary, with snails from sand habitat, mud-flats and salt-pans being examined. While analysis of population differentiation has displayed a high degree of similarity between all three populations, suggesting high levels of genetic mixing, it raises interesting questions regarding the establishment and maintenance of the morphological variations previously observed in the estuary. This, together with the potential for genetic differentiation between geographically distinct populations around the British Isles is currently under investigation. [Poster]

Rapacious Rapanines in a Taxonomic Tangle: A morphological mystery solved with molecular techniques (Mollusca: Neogastropoda: Muricidæ)

MARTINE CLAREMONT

Department of Zoology, Natural History Museum, London, UK.

m.claremont@nhm.ac.uk

The Muricidæ are a large family of taxonomically perplexing, carnivorous marine snails. This perplexity arises, in part, from the prevalence of convergence within the muricids and the consequent morphological similarity. Vermeij and Carlson (2000), using shell characters to expand on anatomical work of Kool (1993), propose a phylogeny of three purported subfamilies of Muricidæ. This morphological phylogeny suggests that two subfamilies, the Rapaninæ and the Ocenebrinæ, are sister clades, and that a third subfamily, the Ergalataxinæ, is derived from the Rapaninæ. Neither study, however, conclusively shows any of the subfamilies to be monophyletic, nor resolves the relationships among the groups. In this study, DNA was obtained from 28 species representing the three subfamilies analysed by Vermeij and Carlson (2000) and Kool (1993), as well as three additional subfamilies used as outgroups. Sequence data from one nuclear and two mitochondrial genes were used to test the monophyly of the three proposed subfamilies, as well as their interrelationships. The genus-level phylogeny of the Rapaninæ was examined to resolve polytomies present in the morphological hypothesis. Finally, the monophyly of the genus Thais is tested.

North-East Atlantic Deep-Sea Invertebrate Collections of the National Museums Scotland  

ZENA FLOODY & SANKURIE PYE

National Museums Scotland, Chambers St, Edinburgh, EH1 1JF.

z.floody@nms.uk & s.pye@nms.ac.uk

The National Museums Scotland is particularly rich in collections of deep-sea (150-4850m) invertebrates of international importance. Most of the deep-sea benthos material was collected by the Scottish Association for Marine Science between 1973 and 1993 (RRS ‘Challenger’, RRS ‘Shackleton’ and RRS ‘Charles Darwin’) from deep sea areas in the North-East Atlantic, including the Rockall Trough, Porcupine Bank, Celtic Sea Bight and the Wyville-Thomson Ridge. Our collection also accommodates material from other localities including the Gorringe Bank, 150 miles off the coast of Portugal. The benthic different collections are arranged primarily taxonomically and subsequently by sea area; they feature exotic, British and historically important specimens as well as recently designated types of invertebrate species.

NMS seeks to facilitate the use of collections for scholarly research by encouraging visits to the collections, loaning research material and collaborating in partnerships. [Poster]

How do the larvae of protostrongylid lungworms (Nematoda: Protostrongylidæ) get into the final host: a simple method for investigating one of the natural routes of sheep’s infection

ORSOLYA FUKÁR & GÁBOR MAJOROS

Department of Parasitology and Zoology, Faculty of Veterinary Science, Szent István University, István str. 2, 1078 Budapest, Hungary.

Majoros.Gabor@aotk.szie.hu & fukar.orsolya@gmail.com

Protostrongylid worms live in very different vertebrate hosts as small and large ruminants, leporids, carnivores, rodents and insectivores. Their larval development takes place exclusively in terrestrial gastropods as intermediate hosts in spite of the fact that none of their definitive host feed preferentially upon snails Researchers dispute over the question, whether the infectious larval stage infects the host animal while still enclosed in the body of the snail or whether it leaves the snail and infects the host as a free living form. Arguments were presented for both possibilities, but the process has not been studied under natural conditions. Here we show a method for marking the snails without influencing the behaviour of them or the sheep, and for detecting marking material in faeces. In an experimental setup, 1650 specimens of heath snails Xerolenta obvia (Menke, 1828) were marked with a specific varnish. The snails were scattered on a 13m² area of a pasture where an adult sheep was allowed to graze for 3 hours after which it was closed into a pen. Faecal material was collected daily. Minute varnish fragments could be detected in it shed 7 days after grazing. Based on marking material detected in the faeces, some snails were ingested in that short time. We hypothesise that the inadvertent consumption of snails could be one of the main routes by which infective protostrongylid larvae enter their final hosts in arid habitats. [Poster]

The influence of parent shell size on the offspring condition in Helix pomatia L. Prospects for heritability assessment.

MARIA GOLAB

International Doctoral Studies in Natural Sciences, Polish Academy of Sciences, Cracow, Poland.

golab@iop.krakow.pl

The growth of young Roman snails Helix pomatia was studied during the period between hatching and second year of life (2004–2005) in order to determine if parents’ body size influences offspring size (shell width, length and diameter). Sixty clutches of parent of known size were collected, measured and then incubated. After hatching, young snails were individually marked and raised in “common garden”, and measured in 6th and 10th weeks after hatching. Shell dimensions of the known parent were positively related to mean egg size. A significant correlation between the parent and the progeny shell dimensions were recorded only 6 weeks after hatching. These two results imply that the maternal effect was responsible for the parent-offspring relationship. In later stages, probably when resources from the egg were exhausted, this relation was disturbed by unknown probably random factors related to individual development. Environmental conditions may therefore have a very strong impact on the development of young Roman snails, which has implications both for conservation and practical aspects of breeding programmes. I assume that there is selection on body size in Roman snail due to its size-related exploitation in Poland. I assume that putative artificial selection could lead to decrease in mean shell size of individuals or can cause changes in age and size at maturation due to different allocation of resources in growth and reproduction under significant predation. Assessment of coefficient of heritability of quantitative traits would help to explain mechanisms that appear in response to exploitation of wild populations of Roman snail by human and would help to improve conservation strategies of this snail. There are several methods for estimating heritability. Apart from traditional rearing methods there are also genetic methods, which provide reliable results in a relatively short time and in natural conditions. Estimating relatedness using genetic markers allows us to detect heritability of snails captured in the wild (Ritland’s method, 1996). However the main obstacle is that highly polymorphic microsatellite loci in Roman snail have not yet been isolated, which hampers any attempts to estimate both the level of exploitation and possible implications of exploitation on body size, maturation, offspring size and number and in consequence the influence of exploitation on population dynamics of this species. [Poster]

Genital allometry in pulmonate snails B. GOŁDYN^1,2, J. M. C. HUTCHINSON¹, TEREZA KOŘÍNKOVÁ^1,3 & H. REISE¹

¹State Museum of Natural History Görlitz. korinko1@natur.cuni.cz.
² Dept. of General Zoology, Adam Mickiewicz University, Poznan
³ Dept. of Zoology, Charles University Prague

The sexually selected ornaments and weapons of gonochorists often show positive allometry; presumably they function better if larger, but only large males can afford proportionately big ones. Do any parts of hermaphrodite genitalia show a similar pattern? For three snail species, stylommathophoran Helix pomatia and the basommatophorans Stagnicola corvus and Stagnicola turricula, we measured various parts of adults’ genital tracts, particularly distal organs involved in sperm transfer or in other interactions with the partner. In H. pomatia, whole genital mass, penis length, length of the bursa stalk, love-dart length and mass of the digitiform glands showed positive allometry. Some genital organs in Stagnicola (vas deferens, proximal genitalia) showed positive allometry in both species, but there were also species differences (positive allometry of the praeputium of S. turricula and bursa stalk of S. corvus, whereas these characters on the other species did not deviate significantly from isometry).

The colonisation of Ireland– myths, mystery and molluscs

ADELE GRINDON

Institute of Genetics, The University of Nottingham,Queen’s Medical Centre, Nottingham, NG7 2UH, UK. 

  plxag2@nottingham.ac.uk

It has long been recognised that the flora and fauna of Ireland has a characteristic “Lusitanian” element, as several species are only found in Ireland and Iberia. Although the land snail Cepæa nemoralis is widespread across Europe, it has been suspected that some populations on the west coast of Ireland may have a ish, specifically Pyrenean, origin because of their characteristic morphology. In order to clarify the origin of the Irish C. nemoralis I have obtained molecular sequence data for this species. Over 1200 individuals from 100 separate locations across Western Europe were collected, and a fragment of the nuclear gene ITS and the mitochondrial genes cytochrome oxidase subunit I (COI) and 16S sequenced. Phylogenetic analysis of these sequences reveals that populations from Ireland probably originate from a source in the Pyrenees or Northern Spain, supporting recent findings in other organisms. In contrast, individuals in the south-west of Ireland additionally share a common haplotype with populations from Britain and France. Given that fossil data indicates that C. nemoralis has been in Ireland for about 8000 years, the significance of these findings in relation to the post-glacial colonisation of Ireland will be discussed.

CLAIRE GUY

Room 514A, The Queen’s University Belfast, The Medical Biology Centre, 97 Lisburn Road, BT9 7BL.

cguy04@qub.ac.uk

The Pacific oyster (Crassostrea gigas) was introduced into Strangford Lough, Northern Ireland in the 1970s for commercial aquaculture purposes. It was assumed that the environmental conditions were unsuitable to facilitate breeding. However, there have been recent reports of feral colonies in the Lough. This investigation was designed to ascertain the extent of the spread and establishment of C. gigas populations away from the initial introduction sites utilising intertidal surveys. The appearance of feral populations generates concerns as the species has been previously associated with major ecological changes due to its establishment in new areas. Further research is required to ascertain the size of the population in the subtidal area and address how the presence of C. gigas is affecting the environment with regards to bioengineering and potential shifts in biodiversity. [Poster]

MICAELA HELLSTRÖM

Environmental and Marine Biology, Åbo Akademi University, Turku, Finland.

michells@abo.fi

Ecosystems that are geographically and ecologically marginal such as brackish waters are expected to show lower genetic diversity within populations and more different genotypes between populations than less extreme environments. The Baltic Sea is geologically young (8000 years) and brackish. It harbours populations which have evolved differently from the Atlantic populations showing divergences due to both bottlenecks and selection of adaptive traits. The present study proposes to compare genetic connectivity and gene flow between populations of three species of mud snails in relation to reproductive strategies and geographical distances in the Baltic Sea by using different DNA markers. Hydrobia ulvæ and Hydrobia ventrosa show direct and pelagic larval development stages respectively. The third species Potamopyrgus antipodarum shows only asexual reproduction in the Baltic Sea and was introduced to the Baltic Sea during the first half of the 20th century. Genetic clines, dispersal and connectivity between the populations are discussed and comparisons with populations in the Atlantic will be made to determine genetic bottlenecks and local adaptation to the environmentally and geologically changing Baltic Sea.

MICHAL HORSÁK & NICOLE CERNOHORSKY

Kotlarska 2, 61137 Brno, Czech Republic.

horsak@sci.muni.cz & nicole4c@seznam.cz

Spring fens are an unusually frequent habitat in the Western Carpathian landscape due to hydrological conditions and geomorphologic characteristics of the bedrock. The bedrock is calcium rich in many regions of this area, which causes a frequent occurrence of calcareous fens. These calcium-rich habitats harbour extremely dense and species rich mollusc communities (up to 30 species at a single site and up to 3000 specimens per 12 litre sample). These fens also host the majority of rare and endangered species (e.g. Vertigo moulinsiana, Vertigo angustior, Cochlicopa nitens, Vallonia enniensis). Furthermore there are fens, which are refugia from the Late Glacial period. These fens have enabled the survival of glacial relicts, which exclusively inhabit fens (Vertigo geyeri and Pupilla alpicola). [Poster]

Distribution and Ecology of Thyasiridæ (Mollusca: Bivalvia) in coastal waters of Hordaland, Norway.

ROZEMARIJN KEUNING¹, CHRISTOFFER SCHANDER^1,2, JON KONGSRUD³ & ENDRE WILLASSEN^3;

¹ Department of Biology, University in Bergen, P.O. box 7800, N-5020, Bergen, Norway. rozemarijn.keuning@student.uib.no
² Centre of Geobiology, Allegaten 41, 5007 Bergen, Norway. christoffer.schander@bio.uib.no
³ Bergen Museum, University in Bergen,P.O. box 7800, N-5020, Bergen, Norway.

jon.kongsrud@zmb.uib.no & endre.willassen@zmb.uib.no

The Thyasiridæ are a group of burrowing bivalves. Several species live in symbiosis with sulphide-oxidizing bacteria. Their burrowing behaviour contributes to oxidizing the sediments, and they mine reducing sediments for sulphides, making the environment attractive to sulphide-intolerant benthos. By revising museum material we want to (1)  provide an overview of the Thyasiridæ along the Hordaland coast, in relation to geographic and bathymetric information, and (2)  use sediment analysis data to investigate the potential of the Thyasiridæ as environmental indicators. Eleven species have so far been recorded. Thyasira succisa and Thyasira polygona are not previously reported from Norway, and Thyasira pygmea is indeed Adontorhina similis showing that Thyasira pygmea is not a trans-Atlantic species. [Poster]

Chromosomal Investigation of Pollicaria (Prosobranchia: Pupinidæ), a poorly known land snail genus from Southeast Asia

BANGON KONGIM¹, CHIRASAK SUTCHARIT², PIYOROS TONGKERD², FRED NAGGS³ & SOMSAK PANHA²

¹ Department of Biology, Faculty of Science,Mahasarakham University, Kantharawichai District, Mahasarakham Province 44150, Thailand. kongimb@yahoo.com
² Animal Systematic Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand.
Piyoros_Tongkerd@yahoo. Jirasak4@yahoo.com & somsakp@sc.chula.ac.th
³ Department of Zoology, Natural History Museum, London SW7 5BD, United Kingdom. F.Naggs@nhm.ac.uk

Species of Pollicaria, the so-called elephant snail, are highly localized on the threatened limestone habitats of Southeast Asia. Samples were collected from limestone areas of Thailand, Laos, Vietnam and Malaysia and karyotyped. The genus exhibited distinct similarities in both haploid and diploid chromosome number (n = 13, 2n = 26) but the fundamental chromosome number (FN) occurred as 46 and 50. Karyotype numbers of Pollicaria myersi from northeastern Thailand were 6m+4sm+2st+1t. The Laos species Pollicaria mouhoti numbers were 4m+6sm+2st+1t and the Malaysian P. elephas numbers 2m+6sm+2st+3t. A karyological comparison carried out on populations of P. gravida from Khe Sen and Cuc Phuong, Vietnam, showed that their karyotype differed, being 3m+7sm+2st+ 1t and 2m+8sm+2st+ 1t. There is a significant difference in shell size between individuals in the two populations and they appear to be distinct species. This is the first chromosome study of Pollicaria. As with other cyclophoroideans, species limits between allopatric populations are extremely difficult to determine and karyotyping is proving to be a valuable tool for determining relationships and species limits. [Poster]

The role of woodland surroundings on the composition of mollusc communities inhabiting tree-less fens: preliminary results

ADAM LACINA

Kotlarska 2, 61137 Brno, Czech Republic.

admice@seznam.cz

The first task of this work was to sort out the available information about ecotone and edge effect, which is closely connected with the topic of this work. It turned out that different groups of organisms act differently to the influence of edge effect, so this particular research on mollusc communities was necessary. The main aim of the research was to find strictly woodland species, which can spread and live on calcareous tree-less fens and factors responsible for it. So far 11 sites in the Czech and Slovak Republics have been studied. Water pH and conductivity, soil calcium content and other factors were measured on each studied site. All the data were statistically processed and afterwards correlated. Further, I tried to find the main factors responsible for the spreading of snail woodland species to tree-less fens. From 7 factors the main ones appeared to be the number of species inhabiting woodland surroundings and the difference between water pH in the fen and soil pH of its surroundings. It turned out that only two strictly woodland species can live on calcareous tree-less fens (Platyla polita and Aegopinella pura). The studied trend of penetration is really unique among woodland snails. Unfortunately the analyzed dataset was not large enough to make any general conclusions.

Habitat requirements and conservation of Vertigo snails – implications for Natura 2000

ANNA LIPINSKA

International Doctoral Studies in Natural Sciences, Polish Academy of Sciences, Cracow, Poland.

lipinska@iop.krakow.pl

Metapopulation conservation is one of the more difficult objectives of nature conservation. The management problems are reinforced by poor knowledge of life histories and habitat requirements of some species.   In molluscs such a problem exists in Vertigo spp. snails, which seems to occur in a metapopulation system and have a very variable spatial distribution. In Eastern Europe their distribution and habitat requirements are poorly recognized, and, very frequently, existing sites are in conflict with developing infrastructure. In spring 2008 I will undertake a research project on spatial aspects of population dynamics and ecology of Vertigo sp. The project focuses on two Vertigo genus species, V. angustior and V. moulinsiana (both included in Habitat Directive EU), which seem to be the most valuable for nature conservation in Poland. The aim of the study is to describe spatial and temporal patterns of population abundance and habitat features crucial for species occurrence. I want to focus on microhabitat scale and its changes during the seasons, which I assume influence the distribution and population dynamics of the snails. I want also to identify ecological factors responsible for the disappearance of small, local populations. I plan to collect data on the species occurrence in Nida valley – this river valley has both completely pristine areas, as well as semi-natural agricultural landscapes, also areas under infrastructural development, with a complex geological substrate. In the first part of the study I want to compare patterns of snails occurrence against the background of GIS maps containing information on geological substratum, relief, plant cover and land development plans. These will allow me to determine large-scale habitat requirements of both species and to recognize the spatial structure of populations. During the second part of the study I want to determine species microhabitat requirements and microscale activity, together with the basic factors regulating population dynamics. This study will allow the creation of ecological niche models for each species based on their habitat preferences. I will formulate basic conservation principles for both species and algorithms for practical population management. [Poster]

Grazing effects on plant and mollusc diversity in woodland and grassland habitats in North Clare and South Galway

MARIA LONG & DANIEL KELLY

Botany Department, School of Natural Sciences, Trinity College Dublin.

lngma@tcd.ie

Grazing animals are known to have significant impacts on biodiversity. It can be difficult, however, to make general statements based on isolated studies and findings due to the amount of variability possible in such studies. It is agreed, however, that there is a lack of experimental data in general on the effects of grazing in Ireland. The Burren, and adjacent limestone areas in north Clare and south Galway, are famous as some of the most botanically interesting and biodiverse areas in Ireland. With regard to the molluscan fauna, about 70 of the 100 Irish land snail species occur within the study region. This project aims to investigate experimentally the impact of grazing on biodiversity in some Burren habitats. This will be done through a network of 12 permanent plots and fenced exclosures. The study will monitor responses among the communities of vascular plants, bryophytes and molluscs. [Poster]

The Helen Marshall Project: Veliger Culture

HELEN MARSHALL

Edward Llwyd Building, Institute of Biological Sciences, University of Wales Aberystwyth, Aberystwyth, Ceredigion, SY23 3DA, UK. hem@aber.ac.uk

A-D Akera bullata at 1, 10, 18 days and adult: Thecacera pennigera at 1, 14 days and adult. Since the advent of opisthobranch research, there have been many studies on veliger growth and development. The ultimate goal of much of this research was to identify the stimulus to metamorphosis and the morphological changes which convert the free swimming veliger into the adult benthic form. Some of these studies have been successful in rearing veligers through metamorphosis, and onto adulthood over several generations. Initially, success was limited to those species with lecithotrophic larvae. These veligers hatch out after an extended period within the egg mass almost fully competent to metamorphose. They only spend a short time within the plankton and settle soon after emerging. As they possess yolk, they do not need to feed, although many can and do when provided with phytoplankton. As knowledge of culturing techniques improved, the number of planktotrophic species taken through metamorphosis has increased. Spawn from several species of nudibranchs was collected from the field and reared using published culture methods. After 10 days at 20°C Thecacera pennigera veligers had developed eyes, a larval heart, an inflated propodium, and had begun retraction of the mantle fold. Despite this, metamorphosis could not be induced when exposed to their prey, Bugula plumosa. Other attempts at culturing the veligers of Onchidoris bilamellata, Cuthona gymnota, Palio nothus, and Ancula gibbosa also failed. Some species exhibited no shell or visceral growth, others exhibited shell growth but failed to develop a larval heart, eyes etc. High mortality, the longevity of the larval stage, the low culture temperature, poor spawn quality, and an inadequate phytoplankton diet were all implemented in a failure to reach competency. Spawn from the Anaspidean, Akera bullata, was gathered from The Fleet, Dorset. The veligers hatch with a shell type 2 and undergo type 2 development. Metamorphosis was successful on a variety of different substrata, however, Chondrus crispus and a biofilm induced metamorphosis faster and in greater numbers. Feeding was not necessary for metamorphosis. Members of the Anaspidea have a broad prey range, therefore it was suggested that the veligers settle in response to a similarly broad range of species.

Where is the Chætodermomorpha (=Caudofoveata) in the tree of life?

NINA THERESE MIKKELSEN¹, ENDRE WILLASSEN¹, CHRISTOFFER SCHANDER² & CHRISTIANE TODT²

¹Zoological Museum, University of Bergen, P.O Box 7800, 5020 Bergen, Norway. nina.mikkelsen@student.uib.no
² Department of Biology, University of Bergen, P.O Box 7800, 5020 Bergen, Norway

Aplacophora (Chætodermomorpha and Neomeniomorpha) are considered basal among Mollusca, but their relative position to “higher” molluscs (i.e. Conchifera) is debated. Understanding these relationships is paramount to understanding the evolution of molluscs and will give important clues towards understanding bilaterian evolution. The main objective of the planned project is constructing a solid hypothesis for phylogeny of Chætodermomorpha. Chætodermomorpha is well defined as a taxon but internal relationships are not settled. Phylogenetic relationships between Chætodermomorpha and other molluscs, and within the polyphyletic genus Falcidens, will be investigated. Morphological characters will be complemented with molecular and ultrastructural characters. The 18S and 28S genes will be sequenced for phylogenetic and COI for barcoding purposes. Histology and electron microscopy will be used to investigate the robustness of selected morphological characters. Chætodermomorpha are common in Scandinavian waters, but often misidentified and many species remain undescribed. New species encountered will be described using standardized techniques and terminology. [Poster]

Population Divergence in the Land Snail, Cepæa nemoralis

SIMIT PATEL

School of Biological Sciences, Philip Lyle Building,University of Reading, Whiteknights, P O Box 68, Reading, RG6 6BX, UK.

s.patel@reading.ac.uk

The terrestrial snail Cepæa nemoralis is highly polymorphic in directly observable shell characters. The underlying genetics of these shell characters is simple, facilitating the demonstration of local adaptation and disruptive selection at individual loci. Morph frequency data has revealed that particular shell morphs are more prevalent in particular habitats. At some sites in the UK, such population divergence occurs over short distances, in the order of a few hundred metres. This means that such divergent populations of C. nemoralis have great potential as natural model systems to study local adaptation. However, there is a lack of molecular data to support the morph frequency data. A genome-wide scan with amplified fragment length polymorphism (AFLP) markers should reveal loci that are highly differentiated between divergent populations of C. nemoralis. Highly differentiated loci are indicative of regions of the genome under selec tion. This technique can help to find the gene(s) involved in local adaptation. [Poster]

Biochemical assessment of taxonomic diversity in the operculate land snail Cyclophorus fulguratus (Gastropoda: Cyclophoridæ) in Thailand

PONGPUN PRASANKOK¹, BANGON KONGIM², PIYOROS TONGKERD⁴, CHIRASAK SUTCHARIT⁴, FRED NAGGS³ & SOMSAK PANHA⁴

¹;Department of Biology, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand
² Department of Biology, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand
³Department of Zoology, The Natural History Museum, London SW7 5BD, UK
⁴Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn Yniversity, Bangkok 10330, Thailand

Cyclophorus fulguratus has been considered to be a widely distributed species in Indochina and shell variation has been treated as being intra-specific. Kongim et al. 2006 used karyotype data to suggest that C. fulguratus, as currently recognised, may include at least two distinct taxa, one distributed in Central and the other in northeastern Thailand. To help clarify the status of C. fulguratus sensu lato we analysed allozymic variation among 13 populations across three geographically disparate regions of Thailand. From both the geographic pattern of fixed allelic differences and topology of a neighbour-joining tree based on Roger’s genetic distance, Central Thailand, Northeastern Thailand and Eastern Thailand groups can be recognised. High genetic heterogeneity demonstrates low gene flow between these groups for which mountain ranges may have acted as significant barriers to gene flow. The extent of genetic distance and allelic differences suggests that these populations should be recognised as three distinct species. [Poster]

Molecular alpha-taxonomy in the Turrinæ (Gastropoda) NICOLAS PUILLANDRE^1,2, SARAH SAMADI¹, MARIE-CATHERINE BOISSELIER¹ & PHILIPPE BOUCHET²

¹MNHN, 43 rue Cuvier, 75005 Paris, France. ,puillandre@mnhn.fr; dubayle@mnhn.fr; sarah@mnhn.fr
² MNHN, 55 rue Buffon, 75005 Paris, France. pbouchet@mnhn.fr

Conoidea, which includes the subfamily Turrinæ, is a hyperdiverse group of marine gastropods, with about 10,000 living species (Bouchet, 1990) defined mostly by shell characters. The great and sometimes continuous variability of these morphological characters renders the delimitation of species complicated. Recently, molecular taxonomy has received increasing attention (Vogler, 2006) to better define species boundaries in poorly known groups, where traditional characters are difficult to assess. Recent cruises in West-Pacific have permitted the achievement of a sampling comprising more than 700 specimens of Turrinæ. Species were not a priori defined in order to accurately estimate intra- and interspecific variability. Sequencing was performed for two genes: the COI mitochondrial gene used for the barcode project and a portion of the 28S nuclear gene. Species boundaries were defined using phylogenetic reconstructions associated to the method described in Pons et al. (2006). Several tens of clusters were thus delimited, mostly including several specimens. Geographic and morphologic information was then used to discuss the alpha-taxonomy of the group. If some clusters appeared easily recognisable on the basis of morphological characters, some gave the impression to include specimens with identical shells, while several shell morphologies were observed in others. Indeed, molecular taxonomy appears to be a fast and accurate way to define clusters of individuals within Turrinæ.

Persistence and conservation of Sri Lankan rainforest snails in a landscape of fragmented forest and modified habitats

DINARZARDE RAHEEM

Department of Zoology, Natural History Museum, London, UK. 

d.raheem@nhm.ac.uk

There is increasing evidence that the modified habitats surrounding fragmented tropical forest have a profound impact on forest biota. Despite this, the value of modified habitats as refugia for tropical forest species has still to be fully explored. I investigated the value of different modified habitats for the persistence and conservation of forest land snails in a 10 x 10 km fragmented rainforest landscape in southern Sri Lanka. My findings support the view that modified habitats cannot be viewed as a substitute for conserving species in natural forest. The results show that whereas intensive monocultures have limited value for conserving rainforest land snails, abandoned monoculture cultivation and home gardens may have a potentially important part to play in the conservation of forest land snails, as both refugia and habitat corridors. This study was carried out as part of a three-year Darwin Initiative project on the land-snail fauna of several south and southeast asian countries.

Land snail shell degradation in forest environments

DAGMAR RIHOVA

Department of Zoology, Charles University, Vinicna 7, 128 48, Prague 2, Czech Republic.

Branta.bernicla@seznam.cz

Little is known on what happens to the shell when a land snail dies. How soon after the death of the snail does degradation commence in forest environments? In order to explore this question I buried shells of nine common species of pulmonate snails in the floor of six types of forest (beechwood, cultivated pine, floodplain, peat bog pine, oak and talus slope forest). Five specimens of each land-snail species were placed in plastic boxes, which were in turn buried in leaf litter on the forest floor. The first set of boxes was excavated after six months, the second set after one year. The early stages of shell degradation vary in different species. In P. hammonis while the periostracum is retained, holes develop in the rest of the shell. In X. obvia degradation occurs in flat pit-like patches, whereas in A. arbustorum the periostracum peels in patches. Small species dissolve entirely after six months. Important factors influencing land-snail shell degradation are shell structure and environmental factors such as soil pH and humidity. Shell degradation may also be influenced by other organisms. [Poster]

Tiny clams of great importance:what can ontogeny teach us about the anomalodesmatan ligament?

ANDRÉ SARTORI & ELIZABETH M. HARPER

Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, U.K. 

andrefsartori@yahoo.com.br

The hinge ligament underwent considerable diversification throughout the evolution of bivalves, the resulting morphological types being widely used in taxonomic and phylogenetic studies of the class. In anomalodesmatans the structure of the ligament is further complicated by the presence of a fully calcified ossicle, usually referred to as lithodesma. Models explaining lithodesma growth and function have concentrated on those taxa with a central lithodesma along the length of the ligament but these fail to explain conditions seen in the Thracioidea where the lithodesma is anteriorly positioned and the ligament largely uncalcified. Investigation of juveniles and adults of the latter group reveals that the lithodesma constitutes the sole hinge component in early ontogenetic stages, the uncalcified ligament appearing latter in a posterior position. These results suggest that heterochronic processes may be responsible for the diversity of ligament structures found in anomalodesmatans.

Financial support: ORSAS; Gates Cambridge Trusts; Emmanuel College.

The land snail assemblages of natural and plant-invaded alluvial ecosystems in the Czech Republic

JITKA SCHLÄGELOVÁ¹ & LUCIE JURICKOVÁ²

¹ Department of Ecology, Charles University, Vinicná 7, CZ-128 44, Praha 2, Czech Republic. jittka@centrum.cz
² Department of Zoology, Charles University, Vinicná 7, CZ-128 44 , Praha 2, Czech Republic. lucie.jurickova@seznam.cz

Our chief objective is a comparison of the snail assemblages of natural and plant-invaded alluvial ecosystems and floodplains of the tributaries of the lower course of the Labe river. This study has great conservation importance because of the projected construction of a sluice on the Labe which is likely to have a negative impact on the native land-snail fauna. Given the relationship between land-snail diversity and soil conditions and the specialised food preferences of many snails, we expect molluscs to be more sensitive indicators of the impact of invasive vegetation on invertebrates than the arthropod taxa studied to date. Our results will also be of use for management of these habitats. [Poster]

Chromosome inheritance in hybrids between the two aquatic snail species Viviparus ater and V. contectus

SBILORDO SONJA

Zoological Museum, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.

bilson@access.uzh.ch

The two dioecious freshwater prosobranchs Viviparus ater and V. contectus hybridize in nature. Although the two species have different chromosome numbers first generation hybrids are fertile in backcrosses with both parental species. The impact of hybridization on the evolution of a species may largely depend on the reproductive mode of the hybrids. If first generation hybrids eliminate the chromosomes of one parental species during gametogenesis gene flow is inhibited but a new hybrid species may arise (= Hybridogenetic system). If hybrids pass on at least some chromosomes of both parental species to the next generation gene introgression may occur (= Mendelian hybrid system). Meiotic behaviour of chromosomes in first generation Viviparus hybrids and chromosome number of backcross offspring indicate a Mendelian hybrid system. Thus, gene introgression by hybridization between these two species may occur.

Physiological adaptations of the cockle Cerastoderma glaucum to different environmental conditions

KATARZYNA TARNOWSKA ² , MACIEJ WOLOWICZ ¹ , ANNE CHENUIL ² JEAN-PIERRE FERAL²

¹ Laboratory of Estuarine Ecology, Institute of Oceanography, University of Gdansk, Al. Pilsudskiego 46, 81-378 Gdynia, Poland
² Marine Station of Endoume, Marseille Oceanology Center, Rue de la Batterie des Lions, 13007 Marseille, France

Physiological differences between populations of the cockle Cerastoderma glaucum were investigated on populations from three European seas: the Baltic Sea (Gulf of Gdansk, Poland), the Mediterranean (Etang du Berre, France), and the North Sea (Veersemeer, The Netherlands). The parameters compared on a seasonal basis were: condition indexes, sex, gonad development stage and respiration rate. Differences in the environmental conditions at the sampling sites were taken into account as well. The results are the part of a PhD project aimed at studying physiological and genetic differences between populations of C. glaucum. Apart from physiological analysis, genetic studies of mitochondrial DNA (COI) and microsatellites were performed as well. The combination of physiological and genetic data should improve our understanding of the mechanisms of acclimatization and adaptation of C. glaucum. It may contribute to establish whether physiological differences are adaptive and provoked by different environmental conditions or rather selectively neutral (“by-products” of divergence).

The influence of parent shell size on the offspring condition in Helix pomatia L. Prospects for heritability assessment.

MARIA GOLAB

International Doctoral Studies in Natural Sciences, Polish Academy of Sciences, Cracow, Poland.

golab@iop.krakow.pl

The growth of young Roman snails Helix pomatia was studied during the period between hatching and second year of life (2004–2005) in order to determine if parents’ body size influences offspring size (shell width, length and diameter). Sixty clutches of parent of known size were collected, measured and then incubated. After hatching, young snails were individually marked and raised in “common garden”, and measured in 6th and 10th weeks after hatching. Shell dimensions of the known parent were positively related to mean egg size. A significant correlation between the parent and the progeny shell dimensions were recorded only 6 weeks after hatching. These two results imply that the maternal effect was responsible for the parent-offspring relationship. In later stages, probably when resources from the egg were exhausted, this relation was disturbed by unknown probably random factors related to individual development. Environmental conditions may therefore have a very strong impact on the development of young Roman snails, which has implications both for conservation and practical aspects of breeding programmes. I assume that there is selection on body size in Roman snail due to its size-related exploitation in Poland. I assume that putative artificial selection could lead to decrease in mean shell size of individuals or can cause changes in age and size at maturation due to different allocation of resources in growth and reproduction under significant predation. Assessment of coefficient of heritability of quantitative traits would help to explain mechanisms that appear in response to exploitation of wild populations of Roman snail by human and would help to improve conservation strategies of this snail. There are several methods for estimating heritability. Apart from traditional rearing methods there are also genetic methods, which provide reliable results in a relatively short time and in natural conditions. Estimating relatedness using genetic markers allows us to detect heritability of snails captured in the wild (Ritland’s method, 1996). However the main obstacle is that highly polymorphic microsatellite loci in Roman snail have not yet been isolated, which hampers any attempts to estimate both the level of exploitation and possible implications of exploitation on body size, maturation, offspring size and number and in consequence the influence of exploitation on population dynamics of this species. [Poster]

Polyphyly across oceans: a molecular phylogeny of the Chromodorididæ (Mollusca, Nudibranchia)

¹Biological Sciences, University of Bristol, Woodland Road, Bristol. BS6 7QA, UH.

lucyturner@bristol.ac.uk

²Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, 92093-0202, USA.

ngwilson@ucsd.edu

The Chromodorididæ is a large and colourful family of nudibranch sea slugs distributed across the world’s oceans. Most diversity is centred in the Indo-Pacific, but several genera are present in multiple ocean basins. The monophyly of these widespread genera had not been tested previously. We used 16S rDNA, COI and 18S rDNA sequence data to generate a molecular phylogeny for this group. Controversy surrounding the placement of the three most basal genera (Cadlina, Cadlinella, Tyrinna) was investigated but not resolved adequately. Sister group relationships were recovered for most monotypic or enigmatic genera. The most derived part of the tree formed two clades that corresponded to ocean basins rather than taxonomic classifications. We recovered evidence of paraphyly or polyphyly in all of the widespread genera examined (Hypselodoris, Glossodoris, Mexichromis, Chromodoris). The basal part of the Chromodorididæ clade, which consists mainly of Chromodoris and Glossodoris, remains fairly unresolved and requires further work.

Functional morphology of freshwater mussels

ALEXANDRA ZIERITZ

Aquatic Ecology Group, Department of Zoology, Downing Street, CB2 3EJ Cambridge, UK.

az259@cam.ac.uk

The shape of a shell is an important feature in bivalve taxonomy. However, knowledge of the functional morphology of a given shell form can help infer habitat preferences and subsequently, to manage endangered species. Furthermore, palaeoenvironmental reconstructions can be drawn when comparing fossil forms with similar recent ones. Despite their extreme inter- and intraspecific shell variability, freshwater mussels (Unionoida) have received little attention in this field of research. We studied the unionid fauna at five marina and five adjacent river sites in the River Thames (UK) from Abingdon to Old Windsor. Marina sites are characterised by slower water flows, finer sediment, higher water temperature and higher phytoplankton densities than in the river. Mussel densities (as estimated by number of mussels per 15 replicate dredges) were not significantly different between the two habitat types. There was a marked difference in the proportions of the three present mussel species between the marina and river sites. Anodonta anatina was more abundant in the marinas, comprising 39% of the mussel population compared with only 12% in the rivers. Conversely, Unio tumidus was more dominant in the river sites than in the marinas (53% versus 19%). While Unio pictorum showed no preference for either of the two habitats (42% and 35% in the marina and river habitats, respectively), this species was numerically the most abundant overall. In all three species, mussels grew faster and to a larger maximum size in the marinas than in the river. Since U. pictorum displayed the greatest morphological variation, further emphasis was laid on a more accurate survey on anatomical and shell characters of this species. A discriminant function analysis for 185 specimens revealed that mussels of the same ‘habitat’ (i.e. marina or river) are more similar in their morphology than those of adjacent sites. River forms are shorter (higher shell height to shell length ratio), which may be adaptive because a shorter protruding posterior part of the shell may help maintain their position at the higher current velocities in the river. Additionally, river forms have proportionately smaller anterior adductor muscles and lower soft tissue dry weight, indicating an inferior body condition in the river than in the marina habitat. Our results illustrate that within a single water-body, strikingly different and consistent phenotypes of unionid mussels can occur over very small geographical distances. Moreover, different species of mussel display consistently different responses to the same microhabitat. Under standing the factors that drive these differences could help us better understand the small- and large-scale patterns in morphology both within and between species, and could enable us to identify optimal conditions for the conservation of endangered mussels.