Protogynous sex reversal in bogue, boops [Linnaeus, 1758] [teleostei: sparidae]

Gonadal anatomy and histology of Boops boops indicated the occurrence of protogynous sex reversal in only a few individuals [about 8%]. The hermaphrodite gonads possess distinct ovarian and testicular parts which develop and function sequentially. Sex reversal occurs by regression of the ovarian part after ovulation, concomitant with a gradual development of the testicular part. At sex reversal, ova are resorbed in two ways; unovulated mateure yolky ova are invaded and phagocytised by granulosa cells while non-yolky ova are not invaded but fragmented and absorbed

Growth rate of the painted comber, serranus scriba linnaeus, 1785 [teleostei: serranidae] from south eastern Mediterranean

Growth of Painted comber, Serranus scribe [L.], from Egyptian Mediterranean waters was studied for 568 females and 295 hermaphrodites. The two sexual phases grew at different rates. Hermaphrodites have a larger adult size, a longer life span, and reach sexual maturity at an earlier size. The von Bertalanffy's asymptotic growth function adequately describes Painted comber's growth; females, L oo =26.86 cm, W oo = 217g, K = 0.2366, to = -1.0181; hermaphrodites; L oo = 33.18, W oo = 398g, K = 0.2194, to = -1.0159. The index of growth performance [Q], shows that the rate of growth is better in hermaphrodites, than females. The well-being of this species under natural conditions is also discussed

Sexuality and hermaphroditism in fish protandrous hermaphroditism in sarpa salpa L teleostri: sparidae

Gonadal anatomy and histology revealed the occurrence of natural prot and rous sex reversal in Sarpa salpa. The gonads of S. salpa possess topographically distinct male and female zones that are well separated by connective tissue. Based on anatomical and histological observations, four types of gonads are distinguished

Protein and energy requirements of [tilapia zillii] fingerlings

Two experiments were conducted to determine the optimum dietary protein and energy requirement of Tilapia zillii fingerlings. In the first experiment, four semipurified, isocaloric [360 kCal ME/100 g diet] diets with protein levels ranging from 25 to 40% were fed to the fish for nine weeks. Maximum growth rates were achieved at 35% protein with P/E ratio of 100 mg crude protein/kCal ME, while protein and energy retention were negatively correlated with P/E ratio in the diets. In the second experiment, T. zillii were fed semipurified diets with a constant P/E ratio of 100 at variable protein [25-40%] and energy [250-400 kCal ME/100 g] levels at 30% protein and 300 kCal ME/100 g. This indicated that as adequate protein and energy levels with the proper P/E ratio, the proportion of dietary protein oxidized for energy can be saved for growth