Abstract :

T

he experiment was carried out in order to study the effect of a rotifer Brachionus plicatilis and encapsulated Artemia nauplii as a live food on survival rate and growth performance for gilthead sea bream Sparus aurata larvae. Gilthead sea bream larvae (20 days old) with body length and weight of (7.3 + 0.20 mm) (5.4 + 0.10 mg) respectively, were stocked in twelve white fiberglass tanks (each of 400 Liter volumes) at a density of 1200-larvae/tank. Treatments were tested as follows, 1) low rotifers and low artemia (LRLA); 2) high rotifers and low artemia (HRLA) 3) low rotifers and high artemia (LRHA); and 4) high rotifers and high artemia (HRHA) for 24 days (10, 30 rotifers and 100, 200 artemia /ml, during the periods 1st, 8th, 9th , 16th, 17th and 24^th days of the feeding experiment). Feeding of higher levels of rotifers and artemia increased the survival rate of S. aurata to 48.96%, however, the lower levels of both resulted in only 12.17 % survival rate. Other intermediate treatments of HRLA or LRHA resulted in better improvements in the survival rates (19.08 and 32.21% respectively) of S. aurata larvae. Values of growth performance of S. aurata larvae (gain in length and weight; average daily (gain in length and weight; and specific growth rate) were significantly increased with increasing the levels of live food from both rotifers and artemia. The results clearly showed the superiority of the higher levels of live artemia in enhancing growth performance of S. aurata larvae than rotifers. Finally, a suitable live food program to improve the survival rates of S. aurata larvae by feeding high levels of rotifers and artemia could be recommended.

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Research :