Text Box:     Number 52 (February 2009)
Text Box: The Malacologist


Organising Committee

Prof. Georges Dussart

Canterbury Christ Church University, North Holmes Road, Canterbury, Kent CT1 1QU (email: gbd...@canterbury.ac.uk)


Dr Dinarzarde Raheem

Zoology Department, Natural History Museum, Cromwell Road, London SW7 5BD (email: d.ra...@nhm.uc.uk)


Dr Manuel Malaquias

Bergen Museum (Natural History Collections) University of Bergen, Muséplass 3, 5007 Bergen, Norway (email: Manu...@bm.uib.no )




Longitudinal distribution of malacofauna in the water of River Danube

Erika Bódis, János N. Nosek, Nándor Oertel & Bence Tóth

Hungary, MTA OBKI Hungarian Danube Research Station of HAS, Göd, Jávorka S. u. 14, 2131, Hungary.  bod...@freemail.hu

Molluscan Forum 2008






Palaeontology Demonstration Room, Natural History Museum, London.  20 November 2008

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Distribution of oysters in Strangford Lough, N. Ireland.

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In this work we examined the spatial pattern of malacofauna

along a second order (Hosszúvölgyi-stream) and third order

stream (Börzsönyi-stream), a medium-sized river (Ipoly) and a

large river (Danube) which are a continuum in the Danube river

system. Investigations were performed at 15 sampling sites in

April of 2007. A total of 3835 individuals belonging to 40 species

were collected. Three species were protected, five of them

were rare and seven were invasive in Hungary. The introduced

Corbicula fluminea was the most wide-spread mussel species

in the whole water system. Based on both species

composition and abundance, different water types can be

distinguished. The highest number of species and individuals

were found in the River Ipoly and in the side-arms of the

River Danube, characterised by a medium-sized water discharge,

while the lowest number of species and individuals were

observed in the second order Hosszúvölgyi stream. Pisidium casertanum, which is a characteristic species of the hypocrenon-epirhithron, was abundant in streams. P. subtruncatum, P. henslowanum, Sphaerium corneum, which were adhered in the hyporhitron-epipotamon comprised dense populations in the River Ipoly and in the side-arms of the River Danube.

The study was supported by the Hungarian Scientific Fund (OTKA) under contract No. T/046180.

Aquaculture of gastropod molluscs with potential for the aquarium industry

Rita Coelho1,2, Gonçalo Calado3,4 & Maria Teresa Dinis1

1Centro de Cičncias do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal

2Zoomarine, EN125 Km65 Guia, 8201-864 Albufeira, Portugal. ipm...@zoomarine.pt

3Universidade Lusófona de Humanidades e Tecnologias, Av. do Campo Grande, 376 1749-024 Lisboa, Portugal.

4 IMAR. FCT/UNL; Quinta da Torre; 2829-516 Monte da Caparica, Portugal.

The purpose of this project was to meet growing demand of the aquarium trade for uncommon gastropods, like nudibranchs, for their high ornamental value, and algae eaters or scavengers species that can be part of a cleaning crew in fresh and salt water aquariums.

The target species for this project were


· Aeolidiella alderi Cocks, 1852. An opisthobranch mollusk (nudibranch). Feeds on several species of anemones, which makes it promising as a plague controler, for problems such as Aiptasia sp. which show uncontrolled growth;





· Hypselodoris villafranca Risso, 1818. One of the prettiest nudibranchs in Chromodoridid family.  It feeds on sponges of the genus Dysidea and has direct development;




· Pomacea bridgesii Reeve, 1856. A prosobranch mollusc, commonly known as an applesnail.

 These freshwater gastropods are very common in several tropical areas like the Amazon River

and feed mainly on vegetal detritus. 


The study methodology has three main branches: life cycle studies, embryonic and larval development studies and species culture optimisation experiments. Ongoing research experiments, achievements and difficulties up to date will be presented.


Predictive power of vegetation and environmental factors for explaining variation of meadow snail communities

Jana Dvoráková & Michal Horsák

Institute of Botany and Zoology, Faculty of Science, Masaryk University, Kotlárská, 611 37 Brno, Czech Republic jana...@seznam.cz

A total of 22 sites were studied in dry and mesic meadows in the White Carpathians (Czech Republic). The sites were chosen along gradients of soil calcium content and soil moisture. Vegetation, Ellenberg plant indicator values (for moisture and soil reaction), plant and moss cover, soil moisture, pH and calcium content were measured for all sampling plots. The aim was to investigate the influence of these factors on snail species composition and richness.

Principal component analysis showed that soil calcium and moisture explained the variation in snail communities the best. Moreover an interaction between these factors was found. Using Redundant analysis with Monte Carlo permutation tests we found only two significant factors: (1) an interaction between soil calcium and moisture; (2) the Ellenberg moisture value, which highly correlated with numbers of alive snail species. Thus, the vegetation appears to be an important predictor for explaining variation in snail communities.

[Poster Presentation]


Invasive species removal: act now, ask questions later

Claire Guy & Dai Roberts

The Queen’s University , Belfast, 97 Lisburn Road, Belfast BT9 7BL, N.I.  cgu...@qub.ac.uk

Invasive species are now thought to be one of the worldwide top ten threats to biodiversity. Species are moved outside their natural range either accidentally, such as through expulsion of ballast water or intentionally for agriculture, horticulture and aquaculture. Often introduced species do not flourish in their new environments; however, some species cope well with translocation and colonise their new locality. This is the case for the Japanese oyster (Crassostrea gigas) which has been translocated for aquaculture throughout the world.

The accepted wisdom in the late 1960s and early 1970s was that water temperatures in northern Europe would not be high enough for

successful breeding and settlement of C. gigas; this was the rationale

for its widespread introduction to revitalise oyster production in the

UK and elsewhere in Europe. However, by the late 1990s, spawning

and settlement of C. gigas, as a result of unusually elevated

temperatures, has been reported widely throughout northern Europe;

the species is also spreading rapidly in the south Atlantic. The spread

of feral C. gigas populations may have detrimental ecological and

economic impacts.

There have been many examples of failed invasive species  management where the opportunity for eradication or control has been lost as time is wasted while gathering detailed information which ultimately bears little impact on future management strategies.  The highest chance of successfully removing a non-native species is during the early stages of population expansion1.

C. gigas was introduced into Strangford Lough, Northern Ireland for commercial aquaculture in the 1970s. In the past five years there have been reports of feral communities away from licensed aquaculture sites. This presentation describes surveys that were carried out in 2007 and 2008 to ascertain distribution and also outlines an eradication trial that has recently been initiated. It is thought that prompt action now, taking advantage of the Allee effect, will help to keep population numbers of C. gigas low and slow down its spread.

1SIMBERLOFF, D. 2003 How much information on population biology is needed to manage introduced species? Conservation Biology 17 (1), 83-92.

Niche creation for cryptofauna by teredinid bivalves in mangrove ecosystems

Ian Wyndom Hendy

University of Portsmouth (Flat 2, 2 Auckland Road, Southsea, Hampshire, UKPO5 3NY)  ianh...@lougars.co.uk

sediments or the nutrients are recycled within other trophic pathways in adjacent ecosystems. Nonetheless, the key catalyst towards the physical breakdown of woody debris and mangrove community structure complexity is facilitated by the wood-boring molluscs, the teredinids.


Land snails on micro scales: interesting patterns and methodological challenges

Zita Kemencei1, Péter Sólymos1, Roland Farkas2, Barna Páll-Gergely3, Ferenc Vilisics1 & Erzsébet Hornung1

1Department of Ecology, Faculty of Veterinary Science, Szent István University, Rottenbiller Str. 50, 1077 Budapest, Hungary. Kemencei.  Zit...@aotk.szie.hu

2Aggtelek National Park Directorate, Jósvafö Hungary.

3Department of General and Applied Ecology, Faculty of Sciences, University of Pécs, Hungary.

Teredinid bivalve molluscs are sometimes considered an economic pest and incur much damage to many man-made structures such as wooden boats, wharfs, piers and piles. However, these wood-boring molluscs may be considered as ecosystem engineers in non-urban environments. Mangrove ecosystems are dynamic, which make life for many flora and fauna species challenging. Nonetheless, large woody debris indicative of mangrove habitats is vital at both the systems level and habitat complexity level. Nearly all mangrove fauna depend upon the hard substratum, and furthermore wood is an important source of nutrients, when broken down it is either retained within mangrove

and eastern aspects, and in sinkhole bottoms.

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Land snails perceive their environment on a fine scale. Few studies however, aim to investigate this relationship explicitly. We investigated the effects of the micro-scale structures on land snail communities, with special emphasis on methodological issues. We studied interacting effects of insolation (as aspect), moisture (as depth) and microhabitat types (live wood, dead wood, rock and litter) in 16 large karstic sinkholes. Shell accumulation rate varied according to microhabitat types and taxonomic groups. Most broken shells were found in rock, and fewer in dead wood microhabitats.

Helicid species tended to be accumulated more than other groups. Species richness and abundance were highest in the rock and the dead wood microhabitats, irrespectively of aspect and depth. For litter and live wood microhabitats, both were higher in northern