Food and Growth of Young-of-the-Year Paddlefish in New York State Ponds

Paddlefish (Polyodon spathula) were extirpated from their native range in New York’s Allegheny River over a hundred years ago. This study examined the feasibility of raising paddlefish in ponds for restoration purposes. Through the months of March- November paddlefish were seined and measured. Pulsed gastric lavage was used to collect 675 stomach samples at 2am and 2pm to determine their diet. Paddlefish fed throughout the day and night. Their growing season in New York was from mid-May through mid-September. Fingerlings (50 mm) paddlefish grew rapidly reaching a good stocking size of 400 mm in just 3 months. In June, during the first month after stocking, paddlefish 92-180 mm ate a diversity of 21 different  insect taxa. By mid-July, when paddlefish reached an average of 283 mm, plankton became the major portion of their diet. Phantom midges, copepods, and nauplius larva were consumed in a higher proportion than they occurred in the pond. Natural production of plankton and insects was sufficient to sustain the paddlefish's dietary needs and resulted in good survival and growth. In NYS rearing paddlefish for restoration purposes in ponds appears to be a viable alternative to tank culture with its higher costs of feed, personnel and facilities.