EXPOSURE UNDER CHOLINE CHLORIDE EXHIBITS SUCCESSFUL GONADAL MATURATION OF INDIAN MAJOR CARPS AND AIR-BREATHING TELEOSTS IN A SEMI-INTENSIVE PISCICULTURE SYSTEM: A HISTOTECHNOLOGICAL INTROSPECTION

Abstract

Surveillance  under direct field-pond application of choline chloride in addition to farm-made-aqua-feed under semi-intensive culture system was investigated on the gonadal maturity  in  two Indian Major Carps Catla catla (Catla) and  Labeo rohita (Rahu) and in two air-breathing teleosts, e.g., Clarias batrachus (Magur) and Anabas testudineus (Koi) reared in a ratio of 2:5:1:1::  Catla:Rahu:Magur:Koi  for a period of 90-d both during dry [November to January as control-dry (CD) and treatment-dry (TD)] and  in breeding seasons [June to August as control-breeding (CB) and treatment-breeding (TB)]. Results were compared with control [C: pond (C) fed only with farm-made-aqua-feed] and treatment [T: ponds (P1 and P2) fed with farm-made-aqua-feed plus feed-grade choline chloride]. The histological observations of ovary under control condition in both the seasons (CD and CB) depicted the follicular layer separation, follicular atresia, resulting into non-fertile oocytes, and ovarian tissue necrosis, declination of yolk granules, while under choline supplementation in both the seasons (TD and TB), the fish species showed ripe and developed oocytes resulting into excellent reproduction performance and steroidogenesis as well as ovulation especially in breeding season. Besides, the exposure of choline (TB) has improved manifolds in the seminiferous tubules of testis of the experimental fish species with the development of increased sertoli cells, development of mature spermatozoa within the epidermis resulting into successful maturation of the sperm and occurrence of better sperm quality having increased motility especially in the breeding season. Finally, choline can trigger the successful ovarian maturation depicting better yield, causing substantial profit to fish farmers.