During the summers of 1967 and 1968, digestion rate and daily food consumption of yearling black bullheads (Ictalurus melas) fed chironomid larvae in the laboratory were compared with similar data for bullheads feeding in Clear Lake. Fish were starved for 3 days and force-fed 0.20 g or 0.30 g of chironomid larvae (Chironomus riparius). Stomachs were mostly empty of food 12 hours after force-feeding. Analysis of covariance showed that the amount of food digested depended on the weight of food fed and time allowed for digestion. Tripling the size of the force-fed meal increased digestion rate 2.4 times. The Bajkov (1935) method indicated digestion rate was slower for fish feeding naturally in the lake. When food was more abundant, daily food consumption in the laboratory for fish fed either 3- or 6% body weight rations of chironomid larvae increased to 5.6% body weight in turbid lake water and 3.6% in nonturbid tap water. Fish sampled in the lake had a daily average of 1.78% of their body weight or 0.24 g of food in their stomachs with peaks of feeding at 1:00 AM and 5:00 PM. Daily food consumption was 0.77 g of food or 5.6% of body weight.
Proceedings of the Iowa Academy of Science
©1970 Iowa Academy of Science, Inc.
Baur, Richard J.
"Digestion Rate of the Clear Lake Black Bullhead,"
Proceedings of the Iowa Academy of Science, 77(1), 112-121.
Available at: https://scholarworks.uni.edu/pias/vol77/iss1/17