Aquaculture of paddlefish in the United States
Aquaculture Research Center, Kentucky State University, Frankfort, KY 40601, USA
Accepted: 18 June 2001
Paddlefish are endemic to most rivers and tributaries of the Mississippi basin and are found in 22 states of the United States. In 1989, US Fish and Wildlife Service (USFWS) listed paddlefish as a category 2 species because data were lacking on its population status. In 1992, USFWS added paddlefish to the list of Appendix II of the Convention on International trade in Endangered Species of Wild Fauna and Flora (CITES) primarily due to concerns about illegal poaching in the international caviar trade. Therefore, paddlefish aquaculture will provide alternative fish sources for the marketplace in the era of strict federal and state regulations on wild populations. Aquaculture of paddlefish is in a research and developmental phase. Most broodstock are obtained from wild sources, though some mature fish have been developed in captivity. Artificial propagation techniques are resulting in > 80 % egg fertility. Larval paddlefish are initially raised in organically fertilized, zooplankton-rich (i.e. Daphnia sp.) ponds, and then trained on extruded trout/salmon diets until the juvenile fish are > 30 cm in total length. Tank culture is also an alternative for raising juvenile fish. Juvenile paddlefish, a filter feeder that requires zooplankton as its primary food, are being grown in reservoirs and in polyculture with channel catfish (Ictalurus punctatus) in Kentucky, Indiana, Missouri and Alabama. Production yields are 200–400 kg·ha–1 in polyculture and in reservoirs ranching resulted in 55–175 kg·ha–1. Reservoir ranching is ideal for caviar production; whereas, paddlefish (1.5 to 4.0 kg) cultured with catfish is for meat production. A system to produce all-female progeny through artificial propagation with sex-inverted, gynogenetic broodstock and attempting to develop optimal cryopreservation techniques for the milt of these unique broodstock is currently being tested. Value-added products such as hot and cold smoked paddlefish are the major effort being developed for the marketplace. Consumer acceptability of value-added products from paddlefish has been better than channel catfish.
Key words: artificial propagation / fry culture / production systems / milt cryopreservation / value-added products / paddlefish / Polyodon spathula
© Elsevier, Ifremer, Cemagref, CNRS, INRA, 2001