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he present study was carried out to study the possibility of early weaning of gilthead sea bream (Sparus aurata) larvae. Therefore seabream larvae divided into different groups and weaned at 35, 40, 45, 50, 55and 60 days post hatching (dph). At the end of the experiment the mean wet weight and length of gilthead seabream were recorded for larvae. Showed that, the late weaning (50, 55 or 60 dph) significantly increased the wet weight and length of larvae compared to larvae groups that early weaned (35 and 40 dph) and the same trend was also observed for larvae after 60 dph. During the entire experimental period the highest SGR values were recorded for groups 60 and 55 dph (3.75 and 3.19), while the lowest SGR recorded for group 35 dph (1.59) indicating that, the late weaning age released the best SGR was compared to the early weaning of gilthead seabream larvae. The obtained results indicated that the late weaning of larvae (60 dph) significantly increased each of protein and fat content of larvae when compared to the early weaning of larvae (35 dph). In conclusion, it can be concluded that, the early weaning could not only improve the growth performance, but also keep the survival rate within the same limits for the original late weaning age.

The use of exogenous hormones to induce final oocyte maturation, ovulation, and spawning has become commonplace in the reproductive protocols for many species. In the present study, African catfish (Clarias gariepinus) were monthly collected from January to December 2011 for studying their monthly reproductive biology. Also, hormonal stimulation was done using ovaprim, human chorionic gonadotropin (hCG), and salmon gonadotropin releasing hormone analog (GnRHa). However, fish (337.2 -718.0 g) were divided into seven groups (each group contained four females and four males) and injected into the dorsal musculature by 0.4, 0.5 ml kg -1 Ovaprim, 1000, 3000 IU kg -1 hCG, and 0.75, 1 ml kg -1 GnRHa. The control group was injected by 0.9% saline. At the dosage tested, gonado-somatic index (GSI), absolute fecundity, ovulation index, egg diameter, fertilization rate were significantly affected in all stimulated groups. It was found that the hormonal treatments are a useful method for commercial African catfish breeders to ensure the continuity of access larvae. However, the best reproductive performance was obtained at 0.5 ml kg -1 ovaprim, 3000 IU kg -1 hCG, and 0.75 ml kg -1 GnRHa.

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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.