INTENSIVE PRODUCTION OF YOY PADDLEFISH Polyodon spathula
Traditional methods for production of paddlefish have relied on natural production of zooplankton and insects such that a fertile pond will support production of several hundred pounds of young of year (YOY) fingerlings in a season. With supplemental feeding, yield may be increased significantly. Previous work at Kentucky State University demonstrated net yields up to 3323 kg/ha.
Investigators on this project observed intensive production of paddlefish where fry were trained on feed, stocked into small impoundments and fed a pelleted ration. Preliminary data collected in 2015 and 2016 demonstrate improvement in methods resulting in significantly higher yield/ha. Fry were trained on feed and presented with supplemental Daphnia as a first food at water temperature of 24 C. Otohime B2 and Zeigler Trout #1 crumbles were presented day and night on a continuous basis during the first month of life after swim-up. After successful feed training, paddlefish were stocked into one of two production units seeded with Daphnia - a pond and a large concrete tank. The fish were fed a high quality floating feed (45% protein, 12% fat). Feed was applied with a belt feeder and by hand. During the summer, feed was delivered at night over a period of 8 to 12 hours with a belt feeder floating in the middle of the pond. Aeration was applied continuously and predators were discouraged whenever possible.
On May 28, 2015, paddlefish (1 g) trained to eat pelleted feed were stocked into a 0.04 ha pond with a volume of approximately 370 m3. At stocking, the 6900 fish weighed about 6.8 kg. On November 19, 2015, 426 kg YOY paddlefish weighing an average of 376 g each were harvested yielding a net production of 10,650 kg/ha. Estimated feed conversion was 0.9 kg feed/kg gain, indicating that natural foods contributed to the diet.
On May 14, 2015, 0.32 g paddlefish trained to eat pelleted feed were stocked into a 0.033 ha concrete tank with a volume of 800 m3. Water did not flow through the tank continuously, but was periodically exchanged late in the season if water quality deteriorated. At stocking, the 11,000 fish weighed 3.7 kg. 325 days later, 1079 kg of paddlefish weighing an average of 275 g each were harvested yielding a net production of 32,696 kg/ha.
These results show there is potential for much higher yield and good feed efficiency of feed trained paddlefish when feeding at night and slowly delivering floating feed to the water surface.