Malacological Society of London

A joint meeting of the Conchological Society of Great Britain and Ireland and the Malacological Society of London at The Linnean Society, Piccadilly, on 8 April 2000

The dawn of the new millennium focuses minds on the future. This is an exciting but also challenging time for the study of molluscs and for the societies that exist to promote it. This meeting was convened with the following aims:

To consider future developments in molluscan studies
To discuss the role of the societies, and of their professional and non-professional membership, in the promotion of molluscan studies
To promote mutual understanding and collaboration between the societies

The meeting was attended by about 60 participants. During the morning, three keynote speakers were invited to give their personal vision of the present state and future of their particular branch of the science. This was followed by an afternoon of shorter talks considering the challenges facing conservation and recording, malacological publishing, the opportunities of information technology, education and outreach, the continuing role of the ënon-professionalí, and the activities of the three main Societies devoted to molluscs. The abstracts of the talks follow.

It is hoped that the meeting will stimulate not only thought and discussion, but also action. There may be more specialized meetings or working groups on topics of particular interest in the future. It is planned to make this the first of a continuing series of annual joint meetings of the Conchological and Malacological Societies.

With more mollusc species listed in the IUCN Red Data Book than any other animal group, there is no shortage of candidate species requiring conservation assistance. Experience has shown that many of these hapless molluscs have the potential to respond well to conservation efforts. However, this high conservation potential all too often goes unrealised due to the fact that so few people are engaged in such work.

The breeding programme for the enid snail (Pachnodus fregatensis) illustrates how easy it can be to provide emergency assistance to a threatened mollusc species. In 1995 rats became established on the Seychelles Island of Fregate where this species is an endemic. The establishment of an ex situ population was considered a prudent conservation action. A small founder group of field collected snails was brought to London Zoo and set up in simple plant propagator units (22x36x17cm) with a 5 cm layer of coir potting compost covered with moss (in which the snails laid their egg clusters). It was found that, providing basic temperature and humidity levels are correctly maintained, reproductive and resultant rearing results can be spectacular. From an original founder base of 20 animals some 400 individuals have been successfully reared through to the sub-adult stage.

A more involved case study is that of the international conservation programme for the Polynesian tree snails belonging to the family Partulidae. Over the last ten years this programme has grown to include 17 participating collections in Europe and North America. Together, these collections care for 30 species, the majority of which are now extinct in the wild (see in situ conservation case study). In many cases the species are further broken down into separate genetic line populations.

Although there are a lot of them, the basic daily care requirements do not greatly differ from those described for the enid snails. Partula and enid snails even share the same artificial diet that has been developed from an analysis of the main wild diet (decayed leaf stalks of Hibiscus tiliaceous). As in the enid snail programme, the Partula snails are maintained in colony groups. This makes it impossible effectively to manage the groups along sound genetic lines or to analyse demographic trends within the populations using traditional individual-based management and analytical tools. These practical considerations have led to the development of 'stage-based' colony management and analysis software that is greatly assisting our ability to conduct long-term programme work for such group-managed animals, including fish, amphibians and even bats. This makes an important point that work with snails has produced some very powerful conservation spin-offs for other animal groups.

In order to be able to provide sufficient ëzoo spaceí (i.e. holding facility, staff time and related resources) for new species entering the Partula programme, it was necessary to calculate target population numbers for each species so that minimum numbers can be held in captivity without compromising the viability of that captive population. An analytical model programme CAPACITY was used to calculate the actual population size required to maintain 90% of starting heterozygosity over 100 years, given the status of the current population. This analysis process identified a need to maintain a target population of 250 adults of each species. The point here is that molluscs can equally benefit from the many conservation tools that have been developed for vertebrates. Finally, it is worth stating that the Partula snail programme has received a huge amount of public and media interest, showing that molluscs can be just as capable of holding their own with more traditional species programmes.

Following widespread extinctions of Partula tree snails due to the misguided introduction of the predator snail Euglandina rosea, an experimental release of three previously sympatric species of Partula back to their native habitat under protected conditions was carried out on Moorea. Release took place into predator-proof reserve constructed in the forest. The reserve consisted of four quadrats to accommodate each of the species, plus one mixed quadrat.

Serious logistic and communication difficulties occurred throughout the course of the experiment, allowing regular incursion by the predator, and a continuing loss of Partula snails. The primary problem was a deficiency in the monitoring and maintenance procedure rather than in the design of the reserve itself. However, all the snails remaining at the close of the experiment were Moorean-bred.

Computer simulations on Vortex, a programme designed to estimate extinction probabilities, demonstrated that a released population of Partula may be able to withstand occassional outbreaks of predation, but only if the possibility of these outbreaks is minimised by scientific monitoring and efficient reserve maintenance. However, supplementation of the population is required to ensure that the necessary high levels of genetic variability

(heterozygosity) are retained. This emphasises the need for the continuing maintenance of healthy captive populations.

Regular demographic demographic surveys of the high islands of French Polynesia are required to determine the distribution and abundance of both the endemic species of tree snails, populations and isolated individuals of endemic species previously believed extinct, as well as a marked decline in numbers of the predator in many areas. All such information impacts on the design of conservation strategies.

Marine Molluscs: their role in marine ecosystems and use in basic biomedical research

Steve Hawkins (The Marine Biological Association, and School of Biological Sciences, University of Southampton)

The sea supports a considerable diversity of molluscs ranging from sedentary or sessile gastropods and bivalves to extremely active cephalopods. These organisms occur in all habitats from the benthos, through the pelagic realm to the sea surface itself (neuston). Adult molluscs are, however, under represented in the holoplankton but the larval stages of benthic animals are prevalent in the plankton.

Most work on the role of molluscs in marine ecosystems has concentrated on benthic species. Experimental manipulations have shown the importance of grazing limpets in structuring rocky shore communities. They prevent growth of seaweeds on barnacle-dominated exposed shores. Predatory whelks are also important in structuring rocky shores, feeding extensively on barnacles and mussels and thus freeing up space.

Bivalve molluscs can have ecosystem-wide effects in enclosed waters. Their filter feeding activities have been shown to control phytoplankton biomass in enclosed waters, even under eutrophic conditions (e.g. San Francisco Harbour). Heavy natural settlement of mussels has led to water quality improvements vital to dockland restoration schemes in Liverpool.

Intertidal molluscs can also be useful indicators of climatic change. Ratios of northern (e.g. Patella vulgata) and southern (e.g. Patella depressa) limpet species have fluctuated in response to climatic change. In recent years P. depressa has become more common around the British Isles. Recording schemes and interested amateurs could make a considerable contribution in such monitoring using easily identifiable intertidal molluscs.

Marine molluscs have also been used extensively in basic physiological and behavioural research. Classic examples include work on learning in Octopus and nerve conduction using squid giant axons. Opisthobranchs have also been used as model organisms for work on memory (e.g. Aplysia) and neural control of feeding movements (e.g. Pleurobranchea).

There are, however, ethical considerations. Cephalopods are very intelligent animals and care must be exercised in their use in invasive experiments. They are also subject to considerable fishing pressure. Thus material for research can become limited due to overfishing. Breeding programmes for Sepia are underway at the Marine Biological Association to provide material for research and ease pressure on natural stocks. Returning to ecological research, care must also be exercised as field experiments can cause disruption of communities and ecosystems.

Molecular methods have an increasingly big impact on most branches of biology, both directly and indirectly. I will briefly discuss the impact and some subsequent changes in systematics and taxonomy currently taking place. Since systematics and taxonomy is the common currency in biology, these changes will also effect everyone else working with molluscs to some extent.

Allozyme electrophoresis, which assesses the variation in proteins, was the first molecular method to be used to a greater extent in areas outside pure molecular biology, such as population biology and systematics. It was first applied to natural populations in 1966 and remained the main technique for twenty years. In 1985 the Polymerase Chain Reaction (PCR) was introduced, a technique that allows us to target and amplify a specific segment of DNA for further manipulation, such as sequencing. It was awarded the Nobel Prize in chemistry in 1993 and is today a fundamental technique. It opened up the molecular tool chest to non-molecular biologists and since the first paper on natural populations in 1989 its use has grown exponentially. It is of great value in systematics (e.g., phylogenies, population delimitation and distribution), biogeography, ecology (e.g., parentage/sibling identification, inbreeding, reproductive success), and whenever the historical aspect ñ in shorter or longer perspective ñ is of interest for the study.

The fundamental unit in biology has traditionally been the species. When using PCR one only needs an extremely small amount of tissue. Thus gene data is obtained from single specimens, and the histories we can infer are of single gene copies in single specimens rather than the histories of species. When considering the history of species (i.e. phylogeny) this is a kind of secondary inference. This highlights another aspect that will have impact on malacology ñ the use of models in biology. Biologists rarely acknowledge that they are actually working with models, but we are.

One such specific model is the species concept. It is the fundamental common currency in biology (have you ever seen a paper not mentioning what species they were studying?), and there are several different species concepts focusing on what their proponents think are important aspects. All concepts have the main flaw in common that they start with a vague idea of what a species is, rather than as a formulation of what concept would be useful for scientific research. Since the molecular tools being deployed to an ever increasing extent describe patterns and processes in more detail within lineages and populations than between ëspeciesí, there is an increasing discrepancy between the species concepts and studies done today.

A radical proposal, and an implementation on a group of polychaetes, was recently published in Systematic Biology. The species concept is here abandoned altogether in taxonomy (that is, we do not name such things ñ although the concept may still be used in other situations, where relevant), and only clades are named. These clades are nested within each other, but no ranks are used. Whichever direction systematics may take (more or less radical) it will affect malacology in the coming years.

Finally, there is also a change in the weather when it comes to nomenclature, i.e. the rules governing how names are to be applied. This is of course a consequence of the change in our perception of taxa and species ñsince we do not think of taxa in the same way as Linnaeus did, it is rational to have rules that follow more closely what we think we are naming today (clades that have evolved, rather than fixed groups created once). In 2000 an alternative code to the ICZN, the PhyloCode, has been released by a workgroup for further discussion. It is not intended to be used yet, but it is a big step in that direction.

It is of course hard to tell whether species-less systematics and the PhyloCode will replace our current system or not ñ most likely not. It is quite certain however that Pandoraís box is open, and that the discussions and new ideas will affect your malacological studies, even if your interest is not primarily systematics. And most likely some new ideas, ignited by the current debate, will replace the current system. These changes are not that far away.

In the past, specialist societies have relied on the combination of voluntary work by professionals, and on a buoyant market for their journals. Now, professionals are subject to increasing pressure at work, and the journals are threatened both by the flood of new specialisms (with associated journals ) and by restrictions on library budgets. Analysis of membership suggests that slow declines and increasing average ages are common.

But specialist societies still have vital roles to play: in promoting basic systematic research, in retaining and disseminating holistic knowledge of their chosen taxa, and in providing expertise and a focus for survey and conservation work.

One way of meeting the challenge is to look to the contribution that informed amateurs can make, both in research and in the retention of skills and knowledge. The combined membership of the molluscan related societies in Britain is a mere 0.06% that of the Royal Society for the Protection of Birds (RSPB). With only 1%, we would have 10,000 members between us!

What follows is a private view and not an official view of the Council of The Society.

The Society has as its aim: The object of The Society shall be the promotion for the benefit of the public of the study of Mollusca in its widest aspectsí (Society Rule 2). Stemming from this The Societyís policies are to promote:

Computerisation will play an increasingly important part in The Societyís activities. The Society needs to develop new ways of making data available, but at the same time The Society will need to ensure that members without information technology are not left out in the cold.

None of the above is achievable without resources. Resources means members, income and capital. Better membership recruitment and retention is vital. The Society needs to improve and to develop ways to get, involve and retain members. These include use of the Web for recruiting young people, students and active retirees, and people who are providing data to Society recording schemes but who are not members. There needs to be much better communication with members, especially new ones.

Finally the activities must lead to outputs: the Journal of Conchology, the Conchologistsí Newsletter, Distribution Atlases and special publications. A revival of Papers for Students needs to get off the ground. All these should be supplemented by data available electronically.

The Malacological Society of London is an international society of some 300 mostly professional members (only 1/3rd of whom live in the UK). It retains strong links to the Natural History Museum, has a leading journal in the field, offers small awards and grants, holds 2-3 short meetings each year (often jointly with other societies) and has the ability to run major international symposia.

Despite the 'professional' tag, I estimate that members spend only one third of their working time in solely malacological pursuits. Biology is making its greatest strides in Integrative Biology, searching for and finding a commonality across a wide range of organisms. Molluscs will be chosen where they provide a useful model. One example is molecular processes in learning where the seahare has replaced Pavlov's dog. But these researchers regard themselves as neurobiologists, or marine biologists etc, and malacology is for most a second string to their bow. I think scientists and artists have something in common the biologist may be attracted by the beauty of form and colour exhibited by molluscs, and is also awestruck by the design of, for example, the tooth of a Conus, and, in a further abstraction, in the concept of underlying patterns such as the cladistic relationships of a group of organisms.

Looking at research interests and undergraduate courses, one might even question whether malacology still exists as a discipline. Nevertheless the diversity of molluscan species and their expansion into many niches, together with their excellent fossil record, and good soft body characters, offer so many opportunities for study that they cannot be ignored. If we consider the applied areas of pest and disease control, shellfish culture, conservation, pharmaceuticals etc., continuing malacological expertise becomes even more significant.

What should The Society do in the future? From an analysis of our strengths, weaknesses, opportunities and threats, we need to develop an Action Plan. This might include the following:

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