Virginia Living Museum
Paddlefish 

State Endangered, Federal Species of Concern
 

Paddlefish (Polyodon spathula) are by far one of the most interesting looking fish on display at the Virginia Living Museum. Their most obvious anatomical feature is their paddle-like snout, or rostrum from which they get their name. Once believed to be used to dig prey out of the bottom, their elongate snouts are more recently thought to aid in the detection of small zooplankton and other invertebrates on which they feed. As filter feeders paddlefish strain water through fine filaments in their gills - a feeding strategy that represents a challenge for any public aquarium. Our aquatic exhibits must be crystal clear and visually pleasing to visitors and therefore must be free from algae or other microscopic organisms that cloud the water. In order to solve this problem, the paddlefish are trained to swim by and take the food directly from the hands of the aquarium staff.  Occasionally, tiny brine shrimp are given to the paddlefish which allows them to filter-feed naturally.

Paddlefish are part of an ancient group of fishes that also include sturgeons; the first paddlefish ancestors in the fossil record date back over 300 million years. Paddlefish are often mistaken by visitors as sharks for good reason, as they share several distinctive characteristics of ancient fishes. Like sharks, both paddlefish and sturgeon have a cartilaginous skeleton and an asymmetrical tail, both common traits of prehistoric fishes. Similar to sharks, paddlefish have the unique ability to detect weak electrical signals given off by potential prey. These sensors are located on the snout and around the gill covering, and are especially helpful to navigate through the turbid waters they typically inhabit.

Once found as far north as Canada, paddlefish can still be found in 22 states ranging from Virginia to Montana, though in 11 of those states their status is considered endangered, threatened or of special concern. Native to the Mississippi basin drainage system as well as several Gulf slope drainages, these unique fish prefer large rivers with pools that are deep enough to escape strong currents. In Virginia, paddlefish can be found in the Clinch and Powell rivers located at the southwestern tip of the state near Tennessee. 

With an estimated lifespan of 30 to 50 years, paddlefish can reach a length of nearly 7 feet, but grow slowly. As common with most long-lived animals, paddlefish do not reach reproductive maturity until 7 to 9 years (males), and 10 to 14 years old (females). They require clean gravel for spawning, but increasingly their eggs are vulnerable to sedimentation caused by damming and river bank construction. Overfishing has also taken its toll on the paddlefish population as they are actively sought after for their meat and eggs (roe). The lucrative caviar business is especially wasteful as fish are often discarded once the roe is collected.  Paddlefish are federally listed as a species for concern, and considered threatened in Virginia waters.

Help pay for my food and care at the Virginia Living Museum by adopting me today.