impact of heavy metals on the energy reserves of lepidotriglae lastovisa from the South-Eastern Mediterranean, Alexandria, Egypt

Lepidotriglae lastovisa were collected monthly over one annual reproductive cycle, from January to December 1994. Total lipid, protein, Pb and Cd content were determined in muscles, liver and gonads of mature [>13 cm length] and immature [8-13 cm length] fishes of both sexes. Mercury content was determined in fish muscles of both sexes at different lengths during one month. Lipids were primarily transported to ovaries prior to fertilization. Energetic lipids were maximal in liver and muscles before spawning and declined to the minimum after spawning, during early winter. L lastovisa spawns two times a year, from February to April, and from August to October. Fish that spawned early still had plenty of fat left in muscles it probably takes its energy from liver fat, while late spawners had low fat reserves [declined by about 70%]. The total energy required for gonad development were significantly parallel in both sexes, and were mostly consumed from lipid mobilization rather than protein. The body lipid content increased significantly during the period of heavy phytoplankton blooms [July and September] and declined in winter. Muscle protein was found to be related to that in the ambient water. Mercury content showed similar distribution patterns in both sexes, being accumulated with growth. The general levels of Pb and Cd were remarkably high in different tissues, which may be traced to the elevated levels in surrounding water, sediments and biota. Bioaccumulation of such metals occurred in almost the same proportion as the total discharge to the area. Such elevations in metals seem to reduce the body energy reserve, where significant inverse correlations between total energy [in the form of lipid and protein] with Cd and Pb was computed and assessed

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