Cyprideis torosa: a model organism for the Ostracoda?

Abstract. In 1990 Danielopol et al. described the ostracod genus Cytherissa as ‘the Drosophila of paleolimnology’ in the sense of a model organism for their purposes at that time. In the intervening years Drosophila is no longer seen by biologists as the perfect test model and, for example, the nematode worm Caenorhabditis elegans is now viewed as preferable because ‘the fly is much more complex than the worm and the anatomy of the nervous system has not reached the level of completeness achieved for the worm’ (Brenner 2003, p. 278). For some years attention has focused on Cyprideis torosa (Jones, 1850), especially since the pioneering work of Rosenfeld & Vesper (1977) on sieve-pore variability in this species in relation to salinity, because torosa is a particularly widely distributed euryhaline living and fossil ostracod species. Cyprideis torosa is not only biogeographically widespread but occurs in a salinity range from freshwater to hypersaline, tolerates a wide range of temperature, oxygen and substrate conditions, and also has a large, well-calcified and easily preserved carapace. The species first occurs in sedimentary formations of early Pleistocene age but may be older. Therefore, it has the potential to be an ostracod model organism. This set of thematic papers is designed to summarize our current knowledge of one of the most important living ostracod species, its distribution, ecology, morphological response to environmental pressures, and molecular characterization, together with our understanding of its origins and value for palaeoenvironmental interpretation. The ultimate aim is to define potentially rewarding research targets using C. torosa as a model organism.