A key to the families and genera of freshwater fishes of Tanzania

The purpose of this key is to facilitate rapid and accurate identification, in the field, for fisheries workers. It is therefore based as much as possible on externalcharacters only and an attempt has been made to keep it simple and straight forward. The only real difficulty arises in clearly demarcating the numerous cichlidgenera of the great lakes, despite the fact that these have been treated in separate sections for each lake. Moreover, it hasn't been possible to revise the key to the lakeNyasa genera (taken from Jackson, 1961) to any significant extent, my experience with L. Nyasa fishes being limited; also, a few new genera have been or are still inthe process of being published and I unfortunatelyhaven't had access to these papers. A short bibliography is appended covering the major publications relevantto the systematics of Tanzania freshwater fishes and the sources from which these keys have been drawn up.