Some aspects of the reproductive biology of the clupeid Ilisha africana (Bloch) off the Lagos Coast, Nigeria
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The maturation development, spawning period, oogenesis, fecundity and sex ratio of Ilisha africana off the Lagos Coast, Nigeria were investigated. Six macroscopic and seven microscopic stages of gonad maturity were identified. Maturity was attained at 12.0 cm total length. Breeding occurred throughout the year with the peak spawning between May and December. Oogenesis consisted of seven stages and breeding marks were observed in the species. Fecundity ranged between 2098 and 11 687 eggs. There was a slightly higher correlation between fecundity and weight than between fecundity and length. The egg diameter varied from 0.77 to 1.35 mm. The overall sex ratio was 1 male to 0.97 female. The females however predominated over the males during most months in the peak breeding period.
[1] M. Htun-Han. The reproductive biology of the dab Limanda limanda (L.) in the North Sea: gonosomatic index, hepatosomatic index and condition factor , 1978 .
[2] M. Htun-Han. The reproductive biology of the dab Limanda limanda (L.) in the North Sea: Seasonal changes in the ovary , 1978 .
[3] C. Macer. The reproductive biology of the horse mackerel Trachurus trachurs (L.) in the North Sea and English Channel , 1974 .
[4] S. O. Facade,et al. The food and feeding interrelationship of the fishes in the Lagos Lagoon , 1973 .