Pioneering Hormone‐Induced Breeding of Esomus danricus in Bangladesh: A Milestone for Conservation and Reproduction

ABSTRACT This study focuses on inducing spawning in the vulnerable fish species Esomus danricus using pituitary gland (PG) extract. Both male and female fish received intramuscular pituitary gland injections in a 1:1 ratio. Female fish were administered doses of 4 (T1), 6 (T2), and 8 mg kg−1 (T3), while male fish received a consistent dose of 2 mg kg−1 across all treatments. Within 3–4 h of injection, the fish exhibited courtship behaviour. The average spawning rates, expressed as mean ± standard deviation, were 27.33% ± 1.77%, 49.43% ± 2.31%, and 77.67% ± 4.87% in April; 35.63% ± 2.85%, 60.67% ± 4.11%, and 87.33% ± 5.87% in May; and 37.69% ± 3.40%, 65.52% ± 4.55%, and 95.67% ± 6.09% in June for T1, T2, and T3, respectively. The latency period for spawning was observed to be 6–9 h across all treatments. The highest fertilisation rate was recorded in June at 93.53% ± 6.12% for T3, while the lowest was in April at 53.67% ± 4.60% for T1. Similarly, the highest hatching rate was detected in June at 91.27% ± 5.78% for T3, and the lowest in April at 30.33% ± 3.91% for T1. Hatching occurred within 20–24 h for all treatments, and post‐yolk sac absorption was noted within 60–72 h. This study successfully standardised breeding doses, offering promising prospects for the conservation and propagation of the native small fish species, Esomus danricus.