The Redside Dace… a Species at Risk

This species has been identified as Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). It is currently being considered for listing under the federal Species at Risk Act (SARA). Protection is afforded through the federal Fisheries Act. If listed under the SARA, it will be afforded additional protection. Under the SARA, a recovery strategy must be developed for this species.

General Description

Clinostomus elongatus

 Illustration by E. Edmondson & H. Chrisp (NYSDC)

The Redside Dace (Clinostomus elongatus) is a very colourful minnow. It is a member of the carp and minnow family Cyprinidae and has the following characteristics:

• Large mouth with a protruding lower jaw;
• Large pectoral fins in males;
• Relatively small scales (59 to 75 lateral scales);
• Adults develop a wide, bright red stripe along the front half of the body; a bright yellow stripe above extends to near the tail fin;
• Colours brighten during the spring and fade during the late summer and fall;
• Males are more brightly coloured than females;
• Prior to spawning, males develop tubercles on the pectoral fins and top of the head; and
• Maximum length is 12 cm.

Distribution

The Redside Dace has a discontinuous range in North America. In the west, it occurs mainly in Wisconsin with smaller populations in Minnesota, Illinois and Iowa. In the south, it is found in Kentucky and West Virginia, extending northeastward in a wide band through Ohio, Pennsylvania and northcentral New York. Its northern extent includes the Lake Superior drainage in the the upper peninsula of Michigan and the north end of Lake Huron in Ontario where it exists in three tributaries. Its Canadian distribution also includes tributaries of western Lake Ontario, the Holland River (Lake Simcoe drainage), and in Irvine Creek (Lake Erie drainage). The Canadian range comprises roughly 5% of its global range.

Redside Dace Distribution in Canada

Habitat and Life History

The Redside Dace is a coolwater species found in pools and slow-flowing areas of small headwater streams with a moderate to high gradient. Overhanging grasses and shrubs, as well as undercut banks, are an important part of their habitat, as are instream boulders and large woody debris. Substrate is variable and includes silt, gravel and boulders. Fish mature at around two years of age. In May, spawning occurs in shallow riffle areas and eggs are often deposited in the nests of other minnows. There is no parental care; however, the nest-guarding male and the nest itself may provide some protection to the eggs. The lifespan of the Redside Dace is generally four years or less.

Diet

The Redside Dace is a visual, surface feeder. It often feeds on terrestrial insects, such as adult flies, at the surface of the lake, leaping several cm in the air to catch them. Its large, upturned mouth is well suited to feeding from below the surface.

Threats

Habitat degradation and loss associated with intensive urbanization is the most important threat to the Redside Dace in Ontario. Contributing factors associated with urban development include changes in the stream structure, such as channel widening and decreased pool depth, removal of bank vegetation that provides cover, food and moderates water temperature, and siltation. Similarly, intensive agricultural practices, such as row cropping and grazing, compromise water quality and habitat of the Redside Dace.

Similar Species

A number of other minnows such as the Northern Redbelly Dace (Phoxinus eos), Finescale Dace (P. neogaeus), Blacknose Dace (Rhinichthys atratulus species complex), and Pearl Dace (Margariscus margarita) also develop a red stripe; however, it extends farther back to the tail.

Text Sources: COSEWIC Status Report 2007.

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