Paddlefish (Polyodon spathula) are considered one of the world's primitive fishes. There have been archaeological finds, dating the existence of paddlefish back 65 million years. They were first reported, historically, in North America when Hernado De Soto remarked about them in the 16th century while exploring the Mississippi River Valley. Although related to the sturgeon, there is only one species of paddlefish in North America. There is a carnivorous species of paddlefish that lives in China.
There is not much known about the paddlefish. They are not an important food or game fish and are rarely caught. However, they are easy to recognize- if you ever get the chance to spot one. There is no other fish that looks like it in Ohio. Averaging 20-48 inches in length, they have a long snout (measuring about a third of the length of its body) shaped like a boat paddle. The snout is not used, as earlier thought, to dig in the stream bottom. Actually, it is covered with taste buds that help them to locate their primary food, plankton. The front of the mouth is directly under the eye. Paddlefish have neither scales nor bony plates on its body. Some early scientists compared to a shark and even misclassified it as a new species of shark in 1792.
Paddlefish live in sluggish, slow moving pools and backwaters of large, slow moving streams waters. They dislike currents. So much so, that where other fish will swim against flooding currents, paddlefish move only during low water stages.
Between April and May, females spawn to produce 7,500 eggs per pound of their body weight. The females become mature at ten years old. Unlike most other fish, paddlefish do not build nests, but instead scatters its eggs over a sandy stream bottom. In ideal habitats, with nothing to stop them, paddlefish may travel up to 200 miles to spawn. Paddlefish average two to twenty pounds in weight. Paddlefish do not begin to spawn until they mature. This occurs in males at seven to eight years. The life expectancy of paddlefish is thirty years.
Paddlefish were reported in Ohio by Moravian missionary David Zeisberger in the eighteenth century. At this time period, they were considered abundant in the state. This status remained even up until 1880 when their large numbers were reported in the Scioto River in Columbus, just before the building of a dam.
Since 1900, paddlefish numbers have dropped dramatically. Excessive commercial harvesting of roe, prevention of reaching its spawning grounds, and general destruction of habitat are among the causes. Today, they are found in the Ohio River and up to the first dam of its major tributaries. Paddlefish are considered threatened not only in the state of Ohio, but throughout the world.