Comparative resistance of channel catfish (Ictalurus punctatus) and channel catfish female × blue catfish (I. furcatus) male hybrid catfish against Aeromonas hydrophila

Fish handling represents a significant stressor within aquaculture systems, frequently compromising the integrity of crucial mucosal barriers. This mechanical disturbance can lead to the development of wounds and skin injuries, thereby providing entry points for opportunistic bacterial pathogens and increasing the fish's susceptibility to disease. This study assessed the survival of channel catfish (Ictalurus punctatus) and channel catfish female × blue catfish (I. furcatus) male hybrids (CB hybrids) following Aeromonas hydrophila infection after passive integrated transponder (PIT) tag injection. The genotype of channel catfish and CB hybrids was identified using the PCR analysis of follistatin (fst) and hepcidin antimicrobial (hamp) gene polymorphisms. The findings demonstrated a noteworthy 15% increase in the overall survival rate in CB hybrid catfish compared with channel catfish. Furthermore, statistical analysis revealed a significantly prolonged (P=0.005) mean survival time in the CB hybrid group following A. hydrophila exposure. Beyond disease resistance, the study also assessed growth performance. Notably, CB hybrid catfish demonstrated significantly greater mean body weight compared to channel catfish in both dying (P= 0.016) and surviving individuals (P<0.0001). Collectively, these results provide evidence of faster growth of CB hybrid catfish in earthen ponds and higher survival rates following handling stress, skin injuries, and exposure to an infectious agent. These traits are of considerable economic importance for sustainable and efficient catfish farming and Aquaculture.