Diet and Reproduction of the Gray Redhorse (Moxostoma congestum) in a Texas Hill Country Stream and Reservoir

ABSTRACT

Reproduction and diet of gray redhorse (Moxostoma congestum) were examined in a Texas Hill Country stream and a central Texas reservoir from September 2004 through August 2005. Temporal patterns in gonadosomatic index and oocyte diameter relative frequency indicated that M. congestum spawns over two distinct periods during spring and likely spawns multiple clutches in each period. Moxostoma congestum is an opportunistic benthic invertivore, with mollusks being the predominant food item in summer and aquatic insects the primary food item in other seasons. Additionally, diets differed between stream and reservoir habitats and among seasons. Though habitat degradation is of concern for M. congestum, our data suggest that it has persisted in habitats disturbed by low-head dam and mainstem reservoir construction due in part to its opportunistic feeding strategy that allows it to adapt to lentic systems.