Induced Breeding of Endangered Labeo calbasu (Hamilton, 1822) Under a Hatchery System

Abstract

Experiment was conducted on the effectiveness of two inducing hormones (Ovaprim and PG) on induced breeding of Labeo calbasu, an endangered Kalibaus species. From April to July of 2022, Labeo calbasu were bred artificially. For the purpose of induced breeding, male and female brood fish weighing between 1.2 kg and 2.0 kg for the male and 1.4 kg and 2.5 kg for the female were chosen, and the sex ratio was maintained at 1:1. PG and LHRH-A were used in the experiment’s design for the period of April, May, June, and July. Under controlled conditions, the impact of two hormones sources on L. calbasu ovulation, fertility, and hatching rate was studied. A single dose of Ovuline® (LHRH-A) (0.44 -0.50 ml/kg body weight) plus two doses of PG (an initial dose of 2.0 mg/kg body weight and a final dose of 4.0-4.5 mg/kg body weight) showed better results in this group of females. In the period of May and June, the ovulation, fertility, and hatching rate of L. calbasu were all better in both PG and LHRH-A. Ovuline® (LHRH-A) 0.15 ml/kg body weight and PG 2 mg/kg body weight provided as a single dose to males resulted in superior spermiation outcomes. Fish weighing 1.55±0.86 kg had the highest GSI value (22.82%) and fecundity (501301±9.96), whereas fish weighing 1.51±0.96 kg had the lowest GSI value (18.24%) and fecundity (350561±8.76). The treatment of PG showed the highest rates of fertilization (98.40±1.17%) and hatching (88.03±2.76%), whereas the treatment of LHRH-A showed the highest rates of fertilization (98.64±0.84%) and hatching (89.55a ±0.88%). According to the results of this experiment, PG and ovaprim are equally effective at causing L. calbasu ovulation, fertilization, and hatching. Both PG and LHRH-A could be applied by hatchery operators to enhance L. calbasu breeding performance by inducing better spawning.