The Feeding Ecology of Paddlefish in the Mermentau River, Louisiana
Nicole A. Smith, Richard E. Condrey, and Bobby C. Reed
Abstract.—We conducted the first comprehensive study of paddlefish Polyodon spathula feeding ecology in Louisiana by examining 129 stomachs collected from the Mermentau River. Paddlefish were sampled monthly using gill nets from March 2002 to February 2003. Copepods and cladocerans occurred more frequently in the stomachs than any other prey, with a frequency of occurrence of 90% and 82%, respectively. Feeding peaked in summer and winter and appeared to shift from copepods in the summer to cladocerans in the winter. There appeared to be no size selectivity of prey, suggesting that paddlefish were indiscriminate planktonic feeders. Calculations of apparent ingestion time indirectly suggest that paddlefish were able to locate dense patches of zooplankton. This study concurs with previous studies of northern and other southern paddlefish populations that paddlefish feed primarily on zooplankton crustaceans such as copepods and cladocerans, although diatoms and other plant material may be periodically important.