Gut Content Analysis of the Headwater Catfish Ictalurus Lupus from Two West Texas Streams‪.‬

Abstract.--Gut contents of headwater catfish Ictalurus lupus were examined from Independence Creek (Pecos River drainage) and Dolan Creek (Devils River drainage) of west Texas. Gut contents consisted of algae and detritus (85%), aquatic insects (9%), crustaceans (3%) and other aquatic and terrestrial organisms (3%). Algal cell walls were ruptured in the lower intestines of I. lupus, suggesting plant nutrients were obtained. Aquatic insects and crustaceans were more prevalent in younger fish than older fish, and less abundant in fish from Dolan Creek than those from Independence Creek. Fewer insects and crustaceans in fish from Dolan Creek may be a result of competition with the introduced smallmouth bass Micropterus dolomieu. However competition, if present, did not equate into lower condition factors (P0.05) for I. lupus. **********