Influence of parental body weight on reproductive success and fry performance of hybrid catfish (Heterobranchus longifilis × Heterobranchus bidorsalis) in controlled hatchery conditions

Abstract

Brood stock quality is essential to a successful and viable fish seed production. Determinant of this quality includes age, physical and genetic makeup. Influence of brood stock body weight on reproduction and performance of Heterobranchus longifilis × H. bidorsalis was studied. Brood stock pairs of varying weights (1 kg, 1.5 kg, and 2 kg) were artificially spawned, and resulting eggs incubated under controlled conditions. The experimental design involved six treatments, (Treatment 1=1kg, Treatment 2=1.5kg, Treatment 3 =2kg, all males = Heterobranchus longifilis while Treatment 4 =1kg, Treatment 5=1.5kg, Treatment 6 =2kg, all males = Heterobranchus bidorsalis), replicated thrice. Parameters assessed included egg count per gram, hatchability, weight gain, specific growth rate, feed conversion ratio (FCR), and survival rate over an 8-week period. Water quality parameters were maintained within optimal ranges. Treatments with moderate-weight females (T1, T2, and T4) produced higher egg counts per gram, while heavier females (T3, T5, and T6) yielded lower counts but with significantly higher hatchability rates. Eggs in T6 had the highest hatchability (56.33%). Growth performance indicators: final weight (5.37±0.47 to 5.07±0.52g), FCR (2.81±0.26 to 3.23±0.50), SGR (0.6697±0.0710 to 0.6608±0.1031%/day) and survival rate (58.33 ± 2.52 to 52.00±10.44%) did not differ significantly (p > 0.05) among treatments, indicating uniform post-hatching performances. The findings highlight a trade-off between fecundity and egg viability, larger brood stock may enhance hatchability despite reduced egg output. For optimal hatchery productivity, brood stock selection should consider not just egg quantity but also fertilization success and larval viability.