Taxonomic assessment of body scales of Cichlidae (Teleostei)

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The tropical freshwater family Cichlidae is famous for its high species diversity, with an estimated number of more than 2,200 species, numerous trophic adaptations and specialized behaviors. As exemplified by previous work, detailed investigations of cichlid fossils can greatly enhance our understanding of how this successful group of fishes evolved. The overall aim of this project is to provide an additional tool for the classification of fossil cichlids based on an assessment of the taxonomic value of body scales (flank and dorsal scales) from extant cichlid species. In the course of the preliminary work, a total of 2,538 body scales derived from 87 ethanol-fixed species of the Ichthyological Collection kept at the Zoological State Collection Munich is available (6 dorsal and 12 flank scales per species, from 141 specimens in all). As the project focuses on the subfamily Pseudocrenilabrinae ('African cichlids'), most of the species selected belong to this subfamily and represent all of its 27 tribes. Some members of the other three cichlid subfamilies (Etroplinae, Ptychochrominae, Cichlinae) were also included. All body scales were extracted following a standardized protocol from distinct body regions; only adult fish specimens were used. The work program envisaged for the proposed project includes (i) photographic documentation of all 2,538 body scales, (ii) preparation of detailed descriptions of scale surface ornamentation, supplemented by measurements of scale length and width (in relation to standard and body lengths of the sampled specimen) and areas of ornamentation, and (iii) the compilation of a 'Cichlidae body-scale atlas'. Such a resource would be very valuable for future taxonomic analyses of fossil Cichlidae from Africa, and would also be a useful tool for studies of extant Cichlidae, e.g. by providing a source of comparative data for the classification of new species.