Protecting Our Native Candy Darter

Candy Darter

FWS, T. Travis Brown

 

The splash of color in our watershed. First documented in Pocahontas County, West Virginia in 1931, this species of darter is native to the upper Kanawha River Basin. Found nowhere else in the world, candy darters find their home in these Central Appalachian waters. Candy darters were listed as a federally endangered species as a result of habitat impacts from historic land uses and the introduction of non-native fish into streams inhabited by candy darter. Together we can work to protect this vibrant species.

 

Identification

Candy darters (Etheostoma osburni) are vibrant fish, known for the colorful spawning colors of the male. Female candy darters have similar markings, although the colors are often muted, with a general olive hue. Candy darters are not the only brightly colored fish in our streams; they can easily be confused with the closely related variegate darter (Etheostoma variatum) and Kanawha darter (Etheostoma kanawhae).

 

Stuart Welsh

 

Stuart Welsh

 

Stuart Welsh/Thomas Uland

 

Distribution

Candy darters are historically only native to the upper Kanawha River Basin, which includes the Gauley, Greenbrier and New River watersheds. Their current distribution is now restricted to a few streams, indicated in green, due to threats that include hybridization with an introduced, closely related darter species (variegate darter) and habitat degradation.

Before the 1990s, candy darters were geographically isolated from other closely related darter species by the natural physical barrier of Kanawha Falls, allowing the candy darter to evolve separately.

 

Habitat

Candy darters typically live in cold, clear, fast moving sections of small to medium-sized rivers. Candy darters also rely on clean gravel on the stream bottom where they can lay their eggs, and the presence of larger cobbles and boulders that they use for shelter.

 

Threats

Hybridization
The historic distribution of the closely related variegate darter was naturally limited to downstream of Kanawha Falls. This species was introduced into the range of the candy darter above the falls, likely by a bait bucket release. The two species can interbreed and produce hybrid offspring. Eventually the hybrids become more variegate darter and less candy darter. Over time, the entire candy darter populations in the stream are eliminated and replaced by variegate darter.

Habitat Loss
Habitat disturbances, including an increase in stream sedimentation, also threaten the candy darter because they need clean gravel and cobbles to lay their eggs and take shelter.

 

Ecosystem Role

Candy darters are an important link in healthy, balanced aquatic food webs. They help convert and transfer energy in aquatic ecosystems by feeding on a variety of macroinvertebrates (including mayflies and caddisflies) which enable candy darter to grow large enough to become prey for larger fish, like trout and bass. Candy darters are also known to help with the reproduction of freshwater mussels, and in turn the mussels constantly work to filter out pollutants in the water to help keep our rivers clean.

 

macroinvertebrates.org

 

How You Can Help

We need your help to protect the candy darter! Many people, animals and fish call these watersheds home, and you can do your part to protect these habitats and the creatures in them.

• Dump unused bait in the trash, rather than in the streams, to prevent the introduction of non-native species into areas where they may cause harm to the aquatic ecosystem.
• Plant trees and other native woody vegetation along streams to stabilize banks and help prevent erosion.
• Maintain a buffer area with native trees and shrubs along streams to help control erosion and filter pollution and sediment before reaching the stream.
• Dispose of chemical waste products properly to prevent them from contaminating soils and polluting streams.
• Become a candy darter advocate by learning more about this colorful species and telling your friends!