Performance and survival of channel catfish (Ictalurus punctatus) and silver catfish (Rhamdia sp.) under confinement in Rio Grande do Sul, Brazil

Abstract

Channel catfish (Ictalurus punctatus) is representative of the Siluriformes order, originating from USA, being cultivated in several countries. Silver catfish (Rhamdia sp.), native to Rio Grande do Sul, belongs to the same order, has omnivorous feeding habit and is considered a species with high cultivation potential. The objective of this study was to evaluate the performance and survival of channel catfish, albine and gray silver catfish in Southern Rio Grande do Sul. The experiment was carried out at Chasqueiro Fish Breeding Station, from October 2001 to January 2002, for 75 days, using 120 catfish juveniles (237.3 g), 120 albine silver catfish juveniles (203.1 g) and 120 gray silver catfish juveniles (226 g). Animals were distributed in 3 earthen tanks with 180 m², each one divided in 3 plots, totalizing 9 divisions with 60 m². Fish were cultivated in a stocking density of 0.6 individual/m² and fed with an extruded commercial ration (36% CP) at the rate of 3% of biomass/day. Weight gain and growth were evaluated through total and standard lengths. Water temperature varied between 13 and 29°C, averaging 20.7°C. Results showed weight gain of 221.6 g, 100.6 g and 90.5 g and survival of 99%, 84% and 91%, for channel catfish, albine and gray silver catfish respectively. It was concluded that channel catfish showed the best productive performance.