Diets of the Arkansas River shiner and peppered chub in the Canadian River, new Mexico and Texas

We examined the digestive tract contents of 1,437 Arkansas River shiners (N otropis girardi) and 1,943 peppered chubs (Macrhybopsis tetranema) collecte d from the Canadian River in New Mexico and Texas from September 1996 to Au gust 1998. Both the Arkansas River shiner and peppered chub are generalist feeders, with terrestrial and aquatic insects representing 28 and 31%, resp ectively, by weight, of their diets. Detritus, plant materials, and sand-si lt represented 26, 6, and 40%, respectively, of the Arkansas River shiner d iet and 25, 28, and 17% of the peppered chub diet. The presence of sand-sil t in the diets of both species suggests they forage among sediments on the river bottom. The common occurrence of terrestrial insects (i.e., Coleopter a, Hymenoptera) in the diet of the Arkansas River shiner indicates this spe cies also feeds in the water column on drifting invertebrates.