The cultivation of tilapias, an African fish which is a major protein source in many developing countries, is hampered by lack of data on the fish's biology and inadequate cooperation between research biologists and fish culturists. This paper reports the proceedings of a conference held to bring together biologists and culturists to review current data and research on tilapias and define research needs for improving tilapia culture. A total of 15 papers presented at conference sessions on tilapia biology, physiology, and culture are provided. The papers cover: (1) tilapias' taxonomy and speciation, ecology and distribution, life histories, and their characteristics when in natural fish communities; (2) tilapias' environmental and reproductive physiology and quantitative and qualitative aspects of their feeding, digestion, and growth; (3) tilapia culture in ponds and cages and tilapia diseases; (4) the use of genetic markers for identifying species and sex; (5) tilapia hybridization; and (6) control of tilapia reproduction and problems in the mass production of hybrid fry. Also provided are a general discussion of the biology and culture of tilapias, a consensus statement of the conference participants, and a list of future research requirements. Appended are a list of 763 references (1849-1981), a general index and indices by species and water bodies, and a list of conference participants.