EFFECT OF TEMPERATURE ON EMBRYONIC AND LARVAL DEVELOPMENT OF BREAM (ABRAMIS-BRAMA L.)

Influence of water temperature on embryonic and larval development of bream (Abramis brama L. was stdied. Eggs of bream were incubated at ei ght constant water temperatures between 13.2 and 26.8 degrees. The tem perature of 21.1 degrees gave highest hatching success, with no abnorm alities in the eleutheroembryos and lowest mortality observed between eyed egg stage and the time of hatching. Developmental rate increased with increasing temperature. Duration of embryonic development (y; hou rs) decreased with increasing incubation temperature (x; degrees) acco rding to the formula: y = 910.1 - 65.88 x + 1.318 x(2). Larvae were re ared at eight constant temperatures ranging from 13.5 to 34.0 degrees. The instantaneous growth rate in wet weight increased with increasing test temperature from 13.5 to 29.9 degrees, and then decreased at hig her temperatures. Individual growth of fish and biomass production rat e were highest at 27.9 degrees. This temperature is considered optimal when food availability and photoperiod are no limiting factors.