Contributors. Preface. On the biochemistry and cell physiology of water (J.S. Clegg, W. Drost-Hansen). Evolution of the fish genome (M.M. Ferguson, F.W. Allendorf). Evolution of mitochondrial enzyme systems in fish: the mitochondrial synthesis of glutamine and citrulline (J.W. Campbell, P.M. Anderson). Frontiers in the study of the biochemistry and molecular biology of vision and luminescence in fishes (M.J. McFall-Ghai, W. Toller). Function and evolution of fish hormonal pheromones (N.E. Stacey, P.W. Sorensen). Urea synthesis of fishes: evolutionary and biochemical perspectives (T.P. Mommsen, P.J. Walsh). The interface of animal and aqueous environment: strategies and constraints on the maintenance of solute balance (S.H. Wright). Carbon dioxide and ammonia metabolism and exchange (P.J. Walsh, R.P Henry). Biochemical aspects of buoyancy in fishes (C.F. Phleger). Movements in water: constraints and adaptations (I.A. Johnston, J.D. Altringham). Endothermy in fish: thermogenesis, ecology and evolution (B.A. Block). Temperature: the ectothermy option (P.W. Hochachka). Pressure as an environmental variable: magnitude and mechanisms of perturbation (J.F. Siebenaller). Species Index. Subject Index.