SOME BIOLOGICAL ASPECTS OF THE RED MULLET, UPENEUS JAPONICUS (HOUTTUYN, 1782) FROM THE GULF OF SUEZ, RED SEA, EGYPT

SOME BIOLOGICAL ASPECTS OF THE RED MULLET,
UPENEUS JAPONICUS (HOUTTUYN, 1782) FROM THE GULF
OF SUEZ, RED SEA, EGYPT
MANAL M. SABRAH
National Institute Of Oceanography And Fisheries, Suez Branch, P.O. Box 182, Suez ,Egypt.
[email protected]
Key words: Reproductive biology, feeding habits, goat fishes, U. japonicus, Gulf of Suez, Red
Sea.
ABSTRACT
Mullidae sp. is considered as one of the most economic fishes in the Red Sea and Gulf
of Suez. They are distributed throughout the tropical and sub-tropical waters around the
world. Reproductive biology and the feeding habits of U. japonicus are studied in the
present paper. Seasonal variations of the gonado-somatic index showed that spawning of
this species takes place in spring. Monthly variations of the maturity stages indicated that
the fish has a distinct spawning season that takes place in the spring months. The length at
first sexual maturity for males and females were 9.6 cm and 9.8 cm respectively. The
relationship between the absolute fecundity and the fish length, weight and age indicated
that the fecundity increases as the fish gets longer, heavier and older. The study of the
feeding habits of U. japonicus revealed that it feeds mainly on crustaceans (63.45%), fish
flesh (26.11%) and nematodes (10.44%). It was also noticed that small fish< 12cm preferred nematodes while the fishes > 12 cm to 19 cm feed mainly on crustaceans.