Effects of broodfish sex ratio, broodfish stocking density, and post‐spawn broodfish holding‐pond density on reproductive efficiency in pond‐spawned Channel Catfish, Ictalurus punctatus

Abstract

Abstract Three trials were conducted to determine the 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. Age, weight, and survival of broodfish were similar for each treatment within trials. 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. Male spawning success (~31%) was similar for 1:1 and 1:4 sex ratios. 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 percentage of egg masses collected per female stocked was higher for the high broodfish density than the low density (34.0 vs. 16.4%), resulting in more eggs/ha and fry/ha for the high stocking density resulting in whole‐farm economic benefits ranging from $323‐828/ha primarily from the reduction in the area required for broodstock. Results indicate the 1:1 male to female broodfish ratio (Trial 1) and high broodfish stocking density (Trial 2) resulted in better reproduction than the 1:4 sex ratio and low broodfish stocking density. The effects of low vs. high broodfish holding‐pond densities didn't affect reproductive output.