Effect of nutritional quality of rotifers and copepods on sea bream (Sparus aurata) fry fish productivity

Abstract

The present study aims to evaluate the effects of zooplankton rotifers and copepods on sea bream Sparus aurata fry fish productivity concerning their growth performance, production, and feeding utilization. Two hundred seventy fry of the sea bream (Sparus aurata) with a mean body weight of 0.11±0.01 g were collected from fish hatchery, Alexandria, Egypt and transported to the fish rearing unit in El-Max Research Station, National Institute of Oceanography and Fishers (NIOF), Alexandria, Egypt and maintained under standard laboratory conditions. Fry fish were divided into 3 experimental groups, 120 fish each. The feeding regime of experimental group was: group 1 (T1) fed natural rotifer diet with 20% commercial diet, group 2 (T2) fed natural copepod diet with 20% commercial diet, group 3 (T3) fed natural rotifer and copepod with 20% commercial diet. The feeding was provided four times a day (8.00 &10:00 am and 12.00 & 2:00pm) at a rate of 15% of the live body weight of the fish. The present results revealed that the environmental factors: temperatures (20°C, 25°C, 30°C) and salinities (20 ppt, 25 ppt, 30 ppt) significantly affect the total number and the growth performance of rotifers (Brachionus plicatilis) and copepods (Cyclops vernalis). Additionally mixing feeding (rotifers with copepods) resulted in significant increase the carbohydrates and lipids percentage in fry fish comparing to feeding with diet