Population biology of sparid fishes in qatari waters 3. Reproductive cycle and fecundity of black-banded Seabream, mylio bifasciatus (forsskal)

Abstract

The reproductive cycle, gonads maturation, gonado-somatic indices (GSI) and fecundity of black-banded seabream Mylio bifasciatus from the Arabian Gulf waters off Qatar were investigated. Bi-weekly samples representing all age groups were collected from January through December, 1993. Gonad maturation occurred in December-March. Spawning was restricted to about 2 weeks from mid to late April (2nd and 3rd quarters of the lunar month). No changes in gonads conditions were noted from May to November. Maximum spawning activity occurred at minimum photoperiod and water temperature. The mean sex ratio was 2 males: 1 female. Males outnumbered females at smaller length groups. No males less than 17 cm, and no females less than 19 cm, while all fish greater than 29 cm, were sexually mature, and 100% of the fish mature at age 5. The relationships between absolute fecundity (lOOO's of ova) and fish lengths and weights were best represented by the following non-linear equations: