Reproductive biology of long whiskered catfish

Abstract

Aspects of reproductive biology such as sexual maturity, spawning, gonadosomatic index, fecundity and gonadal histology of Sperata aor were investigated for a period from August-2012 to July-2013. The species reared in captivity and spawning season was identified. Male and female fish were identified based on morphological characteristics. The spawning season extend 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 increased with total length, body weight and ovary weight. The relationship between fecundity and total length, fecundity and body weight, fecundity and ovary weight of fish were linear and significant. Histological study of ovary of S. aor indicated the presence of four developmental stages: a) Early perinucleolar stage oocytes b) Late perinucleolar stage oocytes c) Yolk vesicle stage oocytes d) Yolk granular stage oocytes. These findings indicated that S. aor has group asynchronous mode of ovarian development and is capable of spawning several times in a year under favourable conditions. Again of histological study of testis indicated the presence of spermatocyte (SC), spermatid (ST) and spermatozoa (SZ) stages. This species build nests during breeding season and fries are found within the nests. The results of the present study will be useful for selective breeding program, conservation and sustainable fishery management of S. aor in its natural habitat.