Paddlefish (Polyodon spathula) are native to most large rivers and their tributaries within the Mississippi River Basin. Paddlefish possess some of the most unique morphological characters of all our freshwater fishes in North America, the most common of these is the elongated paddle-shaped snout or rostrum for which it is named. There has been much confusion historically on what exactly the function of the rostrum was. The professional fisheries community has since learned that the rostrum is an electrosensory organ that the Paddlefish uses to locate the planktonic organisms that it feeds on.
The reproductive characteristics of paddlefish are similar to those of its relatives, the sturgeon. They are a late maturing fish with males becoming mature near age 8 and females nearer to age 15. After reaching maturity, it is uncommon for these fish to partake in spawning events every year. For males, spawning events can be observed as close as every other year while for females the gap is slightly larger at once every three years.
It is thought that the late maturation and spawning periodicity characteristics of Paddlefish coupled with overexploitation and extensive river modifications such as channelization, levees, and dams have likely had the greatest contribution to their population declines. While the removal of the large river training structures is unforeseeable in the near future, we can focus on addressing the overexploitation. Currently many of the states that list Paddlefish as a commercially or recreationally harvestable fish have differing length limits which make management of Paddlefish in our river systems difficult.