The biology of thread bream, Nemipterus japonicas (Bloch)‎ from the Jizan Region of the Red Sea

الملخص EN

-Th e biology o f Ncmiptcrus japonicus was studied during the period 1986-1987, The fish were collected from the Jizan fishing area of the Red Se a by exp erimental trawling and by sampling commerc ial landings .

Monthly data were recorded as len gth/frequency.

length/ weight relationship an d sex-rat ios , Ju venile (3,5-8 ern) bream occurred through mo st of the yea r , Male:Femalc sex-rat io was I : 1.7 , A signifi cant diffe rence was ob served in the lengthweight rel ati on ship between th e sexes.

The smalles t size at first maturity was 10 cm for males anti 9 .5 cm for fem ale s .

This species exhibited yea r-a ro und spawning .

witb peaks between Nov ember to May , Th e maximum gon ado-carca ss rat io was evi de nt a t th at time .

Spawning is: con centrat ed at times of the year when winds ar e weak est.

Rel ative co nditio n a nti visceral-carcass ratio for mature females exhibited monthly tluctu ations and correlation with gonado-carcuss ratio was evident.

This species is mainly carnivorous and stomach content analysis is revealed that it feeds o n crustaceans .

Polychaeta anti sm all fish