Abstract

Present study was conducted to analyse the effect of breeding and non-breeding seasons on histomorphological changes in gonads of Clupisoma naziri. In Khyber Pakhtunkhwa and northern Punjab, Pakistan, 43 mature fish of both sexes were gathered from the Indus River and its tributaries. In the non-breeding season (spring), both testis and ovaries went through a preparatory phase, with thick tunica albuginea and fast spermatogenesis in testes and the formation of cortical alveoli or yolk vesicles in the cortex of the cytoplasm in ovaries. The testicular lobules were loaded with spermatozoa and some spermatogenic cells during breeding season (summer), while the ovaries were filled with mature ovarian follicles. The breeding season is marked by spermatozoa leaking freely from testes and ovaries brimming with completely mature eggs. The gonadosomatic (GSI) results are consistent with the histomorphological results of gonads, as their values peak during breeding season and drop during non-breeding season. C. naziri breeds once a year during the summer season, according to the current study, and this information will aid aqua breeders in the culturing of this commercially significant catfish in Pakistan.

Keywords: Clupisoma naziri, Gonads, Breeding season, Non-breeding season, Gonadosomatic index.