Sunday, November 28, 2010
Bob Laymon - Niangua River Darter Waltz
Niangua River Darter Status: Threatened
Habitat: This fish prefers clear, shallow pools in medium-sized streams. The Niangua darter prefers streams with gravel or rocky bottoms and cannot live in silty water.
Behavior: With its slender snout, the darter probes crevices for aquatic insect larvae, crustaceans and snails. To reproduce, males follow females into shallow riffles and may engage in threat displays with other males before spawning. Males change color during spawning; their bellies become orange-red and their sides develop iridescent blue-green bars.
Why It's Endangered: Dam construction has created barriers in the darter's habitat, fragmenting its range and blocking escape from streams that become polluted or altered. Highway and bridge construction straighten and widen streams, eliminating the small pools in which darters live. Construction and other streamside activities such as clearing brush and gravel dredging has also increased erosion and added silt to the streams, disrupting the fish's habitat.
Other threats include exotic predatory fish such as spotted bass and rock bass, which were introduced before 1940 and have spread throughout the darter's range.