Some aspects of reproduction in long whiskered catfish, sperata aor (Hamilton 1822), from north-east bangladesh

Abstract

Different reproductive aspects such as sexual maturity, spawning, gonadosomatic index, fecundity, and histological changes in gonads of captive reared Sperata aor were investigated for a period of one year. Male and female fish were identified by based on morphological characteristics. The spawning season was found to be extended from May-August. Gonadosomatic index reaches maximum in August and lowest in September. Absolute fecundity varied from 59255 to 70586 with an average value of 64920. Absolute fecundity had been reported to be increased with total length, body weight. Histological study of ovary of S. aor indicated the presence of four developmental stages viz, early perinucleolar s oocytes, late perinucleolar oocytes, yolk vesicle stage and yolk granular stage. Findings reveal that, S. aor has group asynchronous manner of ovarian growth and used to spawn numerous times in a year under favorable environmental conditions. The testes histology represents the presence of spermatocyte, spermatid, and spermatozoa. This species builds nests during breeding season and fries are found within the nests.