Genetic and non-genetic factors influencing reproductive traits of female Clarias magur in a line selected for improved harvest body weight

The Indian catfish species Clarias magur is a potential candidate for aquaculture. ICAR-CIFE is implementing a genetic selection programme to harness its production potential by improving harvest body weight. This study estimated genetic parameters and quantified the effects of non-genetic factors on female reproductive traits in selectively bred individuals. Reproductive traits were recorded from 617 individuals across 174 families over three generations during spawning seasons from 2016 to 2021. The spawning age significantly affected all reproductive traits. In contrast, the spawning year, body weight at tagging (TagBW), and pond significantly affected pre-stripping weight (preSW), post-stripping weight (postSW), and spawning success (SS) ( p < 0.05). Heritability estimates for preSW, postSW, total egg weight (TEW) and egg weight to body weight ratio (EBI) were 0.37 ± 0.10, 0.35 ± 0.09, 0.38 ± 0.11 and 0.22 ± 0.12, respectively. Genetic correlations between reproductive traits ranged from −0.41 to 0.98. Heritability estimates of reproductive traits suggest potential for genetic improvement. The genetic correlation between the preSW and TEW (0.33 ± 0.15) indicates a moderate association, suggesting that selecting magur for body weight may lead to a favourable correlated response in TEW. The overall SS was 37.60%, with 41.69% in males and 34.85% in females. SS exhibited moderate heritability on the logit (observed) scale (0.42 ± 0.01), indicating genetic variation in this binary trait. Overall, these results indicate that reproductive traits possess additive genetic variance, allowing for direct selection, and correlation with preSW suggests that preSW can be used as a selection criterion to improve reproductive performance in this species. • First report of genetic parameters for reproductive traits in Clarias magur showed moderate heritability. • Genetic selection for harvest weight can improve reproductive performance. • Spawning success in Clarias magur is heritable, indicating scope for genetic improvement.