The Paddlefish . . . a Species at Risk

This species has been identified as Extirpated by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). It is listed under the federal Species at Risk Act (SARA) and is afforded protection under the SARA as of June 2004. Additional protection is afforded through the federal Fisheries Act. Under the SARA, a recovery strategy must be developed for this species.

General Description

Polyodon spathula

© Joseph R.Tomelleri

The Paddlefish (Polyodon spathula) is a member of the Paddlefish family (Polyodontidae), one of the most primitive groups of fishes in North America. Similar to its close relatives, the Sturgeons, it has been fished for its eggs, which are processed into caviar. The Paddlefish has the following characteristics:

• Long, spatula-like snout that is longer than the remainder of the head;
• Large, toothless mouth;
• Generally, 50 to 125 cm and 1 to 9 kg but known to grow up to 2 m long and weigh over 70 kg;
• Skin is smooth and scaleless; and
• Bluish grey or bluish olive on dorsal surfaces and lighter, silvery colour on ventral surfaces.

Distribution

The present range of the Paddlefish is the Mississippi River system from Montana to Louisiana, and some smaller rivers draining into the Gulf of Mexico. In Canada, Paddlefish were last reported about 90 years ago when they were thought to have occurred in Lake Huron near Sarnia, the Spanish River, Georgian Bay, and in Lake Helen on the Nipigon River.

Habitat and Life History

Based on information from the Mississippi River population, Paddlefish are highly migratory and live in slow-moving sections of large rivers and lakes, but migrate to large, fast-flowing rivers for spawning.

Paddlefish have a lifespan of at least 30 years. Individuals are slow to develop and males can take up to seven years to reach sexual maturity while females can take 10 to 12 years. Females can lay 150,000 eggs or more, but they may only spawn every two to seven years.

Diet

Paddlefish are primarily invertebrate filter-feeders.

Threats

The Paddlefish has declined across its entire range, due largely to loss of breeding habitat and overfishing. Some characteristics of its life history, such as length of time to reach sexual maturity, make it susceptible to decline and slow to recover. Other threats include pollution, channelization and dam construction, which have blocked access to suitable spawning sites, causing fragmentation of populations.

Similar Species

None

Text Sources: COSEWIC Status Report 2000.

For more information, visit the SARA Registry Website at www.SARAregistry.gc.ca.