Four keynote presentations set the scene for future developments within African malacology. Don Thomas (University of Sussex, UK) identified some of the remaining challenges, including a more intimate understanding of the ecology and limnology of freshwater habitats – a theme echoed throughout the meeting, especially where freshwater habitats were to be artificially manipulated for reduction of snail-borne diseases. For snail control, development of better targeting methods for application of molluscicides, eg. in impregnated snail baits, would be a major step forward. More reliable methods of species identification were stressed, in particular through the use of chemical and molecular markers, because morphological characters are often notoriously ‘plastic‘. Further studies of the factors that shape the population dynamics of r (non-stable) or K (stable) species were called for, as was the integration of this knowledge into bioengineering and river-basin management schemes.
David Rollinson [The Natural History Museum (NHM), UK] gave a molecular perspective, illustrating how DNA technology is innovating malacological research (see Box 1). Considerable genetic heterogeneity within and between snail populations is commonly observed. New phylogenies were presented for Biomphalaria and Bulinus. PCR assays that differentiated Bulinus species involved in Schistosoma haematobium transmission were presented, with examples drawn from West and East Africa (see Box 2). Research is beginning to unravel the molecular mechanisms behind resistance and susceptibility of Biomphalaria to S. mansoni infection. Bulked segregate analysis and differential display methods have identified DNA regions associated with such phenotypic traits. Variable levels of gene expression, eg. cytochrome P450, have been identified, and were associated with infection status.