Food Habits and Growth of Channel Catfish Fry, Ictalurus punctatus

Polyethylene‐lined rearing ponds were used in 1968 and 1969 in the study of effects of certain treatments on food habits and growth of young‐of‐the‐year channel catfish (Ictalurus punctatus). Two ponds were used in 1968, a fed pond and a pond enriched with inorganic fertilizer. In 1969 the study was expanded to four ponds; two receiving treatments similar to those in 1968, a control pond, and a fed‐and‐enriched pond. Weekly samplings of fish, benthos, plankton, and water provided data for determining treatment effects. Enrichment with two inorganic fertilizers variously affected the algae, zooplankton, and benthic communities. No significant difference was noted in the mean growth (weight and length) of fry in the fed pond and in the fed‐and‐enriched pond. Fish production and survival were not improved by enriching ponds. Feeding habits of young‐of‐the‐year channel catfish varied with availability of food items. Analyses of stomach contents indicated that fry, after accepting supplemental feed, consumed many natural foods in direct proportion to their availability. Fry in continually fed ponds were approximately 5 weeks old when they first accepted supplemental feed, which thereafter comprised most of the food they ate and was responsible for their consistent growth rate. The advantage of supplemental feed became especially apparent as the fry became larger and demand for food increased. In the absence of supplemental feed, nonavailability of adequate natural food limited growth.