Caffeine repels slugs and snails

Hawaiian researchers, reported in Nature 417, p 915 (27 June), have found that a 1-2% solution of caffeine (about 25-50 times stronger than a cup of coffee or tea) killed Veronicella cubensis slugs in field tests. A 0.01% solution significantly reduced slugs feeding on cabbage leaves. The heart rate of orchid snails, Zonitoides arboreus, observed directly through their transparent shell, was raised by 0.01% caffeine but reduced at higher concentrations.

Taxonomy on line

A bundle of articles in Nature, (e.g. Vol 418, 362-3, 25 July) point to a reawakening of interest in taxonomy, with a fusion of taxonomy and informatics to create an electronic global framework for taxonomy. In addition to bringing taxonomic information to every desktop, there are moves to develop software for identifying digitised images, rapid DNA sequencing, interactive 'keys', and to train 'parataxonomists' in developing countries where biodiversity is greatest.

Invitation to Aquatic Researchers

The secretary of the Royal Entomological Society of London, John Badmin, invites members with aquatic interests to the inaugural meeting of the aquatic insects special interest group on December 4^th at the RES rooms at 41 Queen's Gate (the road on the LHS of the Natural History Museum). The evening lecture is on Visualisation and Interpretation of Ecological Data using Advanced Computer Techniques with special reference to Aquatic Insects. Admission is free. If interested, contact the convenor, Craig Macadam on 0131 445 6723 or crai...@scottishwater.co.uk.

Other meetings of the RES are listed on their website http://www.royensoc.co.uk

Conus toxin a potent pain-killer

A University of Melbourne team led by Bruce Livett reported that an alpha-conotoxin, ACV1, from an Australian Conus is a potent analgesic in rats. Conotoxins paralyse prey, but in small doses block pain. The tests suggest the chemical may be 10,000 more potent than morphine, non-addictive and without side effects. Prialt, another conotoxin intended as an alternative to morphine can cause blurred vision and confusion , but ACV1 targets a different class of receptors. ACV1 also accelerated recovery of injured nerves. From Nature Science Update 19 July (http://www.nature.com/nsu).

Model pupil learns consequences of its action

Aplysia is a model for understanding how animals learn, but most studies look at classical or Pavlovian conditioning, tracing the pathways from the conditioned and unconditioned stimuli to their convergence. The 'other type' of learning, operant conditioning, has received less attention, because an association is made between an action and a reward or punishment - such as biting and a food reward. Björn Brembs and colleagues, in Science 296, 1706-9, showed that the operant response (biting) can be reinforced by a food-related reward (stimulation of the oesophageal nerve), and the association is remembered. Brembs et al. then showed that the activity of a buccal ganglion cell, B51, which is essential in generating the biting rhythm, had a lower threshold in trained animals.

Australian Advanced Mollusc Course

The University of Wollongong with staff from the Australian Museum is offering a 12 day residential course in February 2003. The course covers biology, diversity, conservation, classification and importance to man. The course will include lectures, practicals and field excursions in marine, freshwater and terrestrial habitats. Details and application form at http://www.uow.edu.au/science/biol/molluscs

Malacologia journal web site

http://malacologia.fieldmuseum.org

Environmental oestrogens affect aquatic gastropods

The freshwater ampullariid Marisa cornuarietis and the marine dogwhelk Nucella lapillus are affected by the xeno-oestrogen bisphenol-A, at environmentally relevant levels. Bisphenol-A is mainly used in the manufacture of polycarbonate plastics and epoxy resins. At 1ug/L, it produces 'superfemales' with morphological changes including gross malformation of the pallial section of the oviduct, massive stimulation of oocytes and increased mortality in Marisa, and reduction of the penis in Nucella. Marisa is widespread in the Caribbean and Central and South America, is used as a biocontrol for schistosomiasis, and is often kept in aquaria.

The Frankfurt researchers, J Oehlmann, U Schulte-Oehlmann, M Tillmann and B Markert (Ecotoxicology 9, 383-397 (2000)), suggested that M. cornuarietis could be a model organism for endocrine-mimetics. Steve Dungey of the U.K. Environment Agency, in collaboration with experts, has prepared a paper on current knowledge of the biology and testing conditions for Marisa, as a stage towards devising a definitive toxicity test to determine a dose-response and critical effect concentration for bisphenol-A in Marisa. He would be pleased to hear from anyone who might be able to provide information (stev...@environment-agency.gov.uk).

A snail model for rapid, single-gene speciation

Since the work of Boycott in 1930, geneticists have known that shell coiling is inherited at a single locus, but the form of the gene in the mother determines whether the offspring are left or right coiled, independent of which form of the gene those offspring carry. Thus a sinistral mutation in one snail in a dextral population would pass the sinistral form of the gene to the offspring, but the offspring would themselves be dextral and, thus, able to mate with the rest of the population. In stout shelled forms, unlike narrow spired forms, coiling direction forms a reproductive isolating mechanism, because left- and right-coiled partners cannot copulate. Stone and Björklund (Proc. Roy. Soc. Lond. B 269, 861-865 (2002)) use computer models to demonstrate the conditions under which local populations can achieve rapid macroscopic phenotypic transformation.