Reproductive biology of Grammoplites suppositus (Troschel, 1840) (Teleostei: Platycephalidae) in coastal waters of the Persian Gulf

This study was conducted to determine reproductive biology of Spotfin flathead Grammoplites suppositus for a period 16 months from November 2016 to April 2018 in coastal waters of the Persian Gulf. Sampling was carried out by shrimp bottom trawl net as bycatch and a total of 635 fish were examined during the study period. The recorded results showed that the sex ratio between male:female was not significantly being 1:1 throughout the study period with 55.28% of fish was female. Analysis of morphological maturity stages of ovary was showed that G. suppositus can spawn in throughout the year with a peak from November to March. Also, the GSI was uptrend in November to February and then declined from March in the region. The minimum size of the female G. suppositus that reaches the sexual maturity was observed in the size classes 160-179 mm of total length. The L m50 % was estimated at 199.4 mm of total length for this flathead fish.