Effects of male to female broodfish ratio, broodpond stocking density, and post-spawn broodfish holding-pond density on reproductive efficiency in pond-spawned channel catfish, Ictulurus punctatus.

Authors: Bosworth, Brian; Waldbieser, Geoffrey - Geoff; ENGLE, CAROLE - Engle-Stone Aquatics, Llc; KUMAR, GANESH - Mississippi State University

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/2/2023
Publication Date: 11/2/2023
Citation: Bosworth, B.G., Waldbieser, G.C., Engle, C., Kumar, G. 2023. Effects of male to female broodfish ratio, broodpond stocking density, and post-spawn broodfish holding-pond density on reproductive efficiency in pond-spawned channel catfish, Ictulurus punctatus.. North American Journal of Aquaculture. 86:130-140. https://doi.org/10.1002/naaq.10321.
DOI: https://doi.org/10.1002/naaq.10321

Interpretive Summary: Channel catfish are typically spawned on commercial farms in earthen ponds in the spring and early summer. USDA scientists examined effects of 1:1 vs. 1:4 male to female broodfish sex ratios, high (2050 kg/ha) vs. low (1,065 kg/ha) broodfish stocking densities, and high (5,780 kg/ha) vs. low (1525 kg/ha) post-spawn broodfish holding pond densities on the quantity of egg and fry produced in pond-spawned channel catfish. The 1:1 male to female sex ratio produced more eggs and fry per hectare of broodponds than the 1:4 sex ratio, and the high density broodponds produced more eggs and fry per hectare than the low density broodpond ponds. There was a trend for better fry production for the low density post-spawn broodfish holding ponds compared to the high density post-spawn broodfish holding ponds. The reduced egg and fry production in the 1:4 sex ratio and low density broodfish stocking densities appears to be related to establishment of a male dominance hierarchy in catfish spawning ponds that prevents a high percentage of males from participating in reproduction. The results suggest commercial catfish farmers would not benefit by decreasing the number of males relative to females in broodfish ponds, but could improve reproductive efficiency by increasing the stocking density in broodfish ponds.

Technical Abstract: Three trials were conducted to determine effects of broodfish management on reproductive efficiency of pond-spawned channel catfish, Ictalurus punctatus. Trial 1 compared male to female broodfish sex ratios of 1:1 vs. 1:4; Trial 2 compared low (1,065 kg/ha) vs. high (2050 kg/ha) broodfish stocking densities; and Trial 3 compared low (1525 kg/ha) and high (5,780 kg/ha) post-spawn broodfish holding-pond densities on measures of reproductive efficiency. Males had lower survival than females in all trials. Within trial and sex, treatments did not differ for age, weight or survival of broodfish. A higher percentage of females spawned at the 1:1 male to female ratio than at the 1:4 ratio (40.8% vs 12.5%) resulting in more eggs/ha, eggs/kg of broodfish, fry/ha and fry/kg of broodfish for the 1:1 ratio compared to the 1:4 ratio. The percentage of males spawning (~31%) was similar for sex ratios in Trial 1. Spawning fish weighed more than non-spawning fish for both sexes and surviving males weighed less than non-surviving males in Trial 1. In Trial 2 the number of egg masses per female stocked was higher for the high broodfish density than the low density (0.34 vs. 0.16%) resulting in more eggs/ha and fry/ha for the high stocking density. There was a trend for the low post-spawn broodfish holding-pond density fish to produce more eggs/ha and fry/ha than the high post-spawn holding density in Trial 3. Results indicate the 1:1 male to female broodfish ratio, high broodpond stocking density, and low post-spawn holding-pond density resulted in better reproduction than the 1:4 sex ratio, low broodfish stocking density and high post-spawn holding-pond density.