Micro-Anatomical and Morpho-Histological studies of Ovary of stone carp Psilorhynchus pseudecheneis (Menon & Dutta, 1964) from Trishuli river of Nepal

Abstract

Stone carp Psilorhynchus pseudecheneis were monthly sampled throughout a year and the histological analysis of their ovaries was done to determine the changes occurring in ovarian development. Based on histological examination of the ovaries, the organic process of P. pseudecheneis undergoes distinct cyclic and seasonal morphological changes. Five different developmental stages were identified under three major categories: pre-spawning (immature, maturing, mature), spawning (ripe-running) and post-spawning (spent). The peak spawning period of carp was noticed during December to February. The gonadosomatic index (GSI) and ova diameter ranged from 0.79 to 3.61% and 543 to 1123 µm respectively. The highest mean GSI (3.61 ± 0.16) and oocyte diameter (1123 ± 55 µm) were observed in December indicating that during this month the gonadal development reached maturity.