Population biology of sparid fishes in qatari waters. 1 - reproductive cycle and fecundity of longspine seabream, Argyrops spinifer (Forskal)

Abstract

The reproductive cycle, gonads maturation, gonado-somatic indices (GSI) and fecundity of longspine seabream Argyrops spinifer from the Arabian Gulf waters off Qatar were investigated. Bi-weekly samples representing all age groups were collected from November, 1991 through May, 1993. Gonad maturation occurred in December-March. Spawning was restricted to about 15 days from mid to late April. No changes in gonad conditions were noted from May to October. Maximum spawning activity occurred at minimum photoperiod and water temperature. No fish smaller than 16 cm in length, and all fish greater than 26 cm, were sexually mature, and 100% of the fish mature at age 4. The relationship between absolute fecundity ( 1000' s of ova) and fish length was best represented by the following non-linear equation: log F = 2.1488 + 1.99 log L ( r = 0.899 ), while a linear equation; F = 34.18 + 0.195 W, (r = 0.984) was found between fecundity and fish weight