Effects of photoperiod on growth and feed utilization of juvenile Black Sea turbot (Psetta maeotica)

Abstract

A study was conducted to determine the effect of different photoperiods on the growth and survival of juveniles of the Black Sea turbot (Psetta maeotica). Juvenile turbot (32.17 +/- 0.1 g) were reared under one of three experimental photoperiod regimes: natural, continuous light, or extended light (18 h light:6 h dark). The turbot were held in sea water (18 ppt) at 15-24 degrees C from May 27 to July 29, 2004. The maximum growth rate, feed efficiency, and specific growth rate were recorded in the fish exposed to the extended light period (p < 0.05). Continuous light may have acted as an irritant, inducing stress, suppressing growth, and reducing feed intake.