NEOSHO MADTOM - Noturus placidus
The Neosho madtom is the smallest catfish in Missouri. They live under rocks in riffles or runs, always in clear water in areas with loosely packed gravel. They are vulnerable to drought, pollution, and habitat changes due to reservoir construction. The species is listed ENDANGERED by the Missouri Department of Conservation and THREATENED by the U.S. Fish and Wildlife Service.
Identification
The Neosho madtom is the smallest catfish in Missouri. It is mottled dark- and light-brown, with dark bars on the tail fin. Adults are commonly 1.8 to 2.7 inches long to a maximum of three inches.
The Neosho madtom and the brindled madtom look similar. Both have mottled coloration with dark vertical bars on the caudal fin. The best way to tell them apart is to observe the adipose fin (located dorsally in front of the tail fin). The dark color at the base of the fin does not extend to the outer edge of the fin in the Neosho madtom. And while the dorsal and anal fins of the Neosho madtom have dusky streaks, they are not black or dark-tipped as in the brindled madtom.
For a technical description of this animal refer to:
- Pflieger, W.L. 1991. The Fishes of Missouri. Missouri Department of Conservation. Jefferson City, Missouri. 343 pp.
- Cross, F.B. and J.T. Collins. 1995. Fishes in Kansas. 2nd edition, University Press of Kansas. Lawrence, Kansas. 315 pp.
Life History
Little is known about the life history of this fish. Neosho madtoms probably only live two or three years.
Neosho madtoms feed on aquatic insects including the larvae of caddisflies, mayflies, dipterans, and midges. They are most active at night, foraging primarily within three hours after sunset. Madtoms live at the bottom of the stream, even preferring the spaces in the gravel and cobble. They seldom swim against the current for more than a few seconds. Because they can move through the gravel and are mostly active at night, Neosho madtoms can be difficult to detect.
Exactly when, how and under what circumstances Neosho madtoms breed and lay eggs is poorly understood, but it is probably very similar to other madtoms. Egg development begins in March. Spawning typically takes place in June and July, which coincides with the period of peak streamflow in the Neosho River drainage.
Madtoms make cavity nests in protected hiding places. After the eggs are laid they are guarded by one or both parents. Some madtoms also guard newly hatched fish. Large numbers of young madtoms have been observed in the quiet water below riffles, suggesting that young-of-the-year fish probably drift downstream to develop, or perhaps the adults move off the riffle to spawn.
Habitat and Distribution
Neosho madtoms are restricted to the stream riffles of the Neosho, Cottonwood and Spring Rivers of the Arkansas River basin. These streams are medium-sized, moderate gradient rivers with abundant gravel and cobble. Madtoms generally live among the riffles under rocks, often moving through loosely packed gravel.
While the entire distribution of the Neosho madtom is 250-300 stream miles of the Arkansas River basin, this species is peripheral in Missouri, inhabiting only 5 to 7 stream miles on the Spring River. Biologists have surveyed several hundred sites in southeastern Missouri, but they are quite certain that this fish has always had a limited range in Missouri. Actions to protect and manage this species are necessarily limited to this stretch of stream.
Cause of Historic Decline
The Neosho madtom is vulnerable to drought, habitat disturbance, and pollution. While the species has declined measurably in some parts of their range, Neosho madtoms still inhabit the same part of Missouri, presumably in secure numbers.
Reservoir construction flooded riffles and changed available habitats in Kansas and Oklahoma. Land clearing in the Neosho River watershed caused increased sedimentation of riffles and further declines in habitat quality. Sand and gravel mining disturbs or destroys riffles used by this fish and affect other stream fish and wildlife as well.
Current Threats to Neosho Madtom
- Dams and Impoundments Construction of dams has flooded many of the riffle areas used by Neosho madtoms and has changed the temperature, turbidity, nutrient level, and water flow. No impoundments have been proposed in the Missouri portion of the range.
- Unrestricted sand and gravel removal Poorly managed sand and gravel mining can significantly impact riffle habitats and affect fish habitat. Even if removing the gravel is not a direct impact, siltation and related stream impacts can affect spawning areas.
- Habitat degradation Agricultural runoff containing pesticide chemicals and waste from livestock can affect species directly, or decrease water quality so that stream fish and wildlife suffer. Unrestricted access by cattle in riparian areas increases sediments and organic matter in streams and further degrade riffle habitat.
Protection and Management: Steps Toward Recovery
- Watershed impoundments There are no proposed large stream impoundments at this time.
- Sand and gravel removal Follow proper gravel and sand removal procedures outlined in the Missouri In- stream Sand and Gravel Removal Guidelines prepared by the Missouri Department of Conservation and Department of Natural Resources. These guidelines recommend that the landowner leave a minimum 20-foot buffer zone between the water line and the excavation area and not mine within 20 feet of streamside vegetation. Never alter stream channels or dewater gravel beds. To the degree possible, do not remove gravel during the Neosho madtom spawning season (April 15 to July 15). For more information and a copy of the pamphlet, contact: Missouri Department of Conservation Policy Coordination Section P. O. Box 180 Jefferson City, MO 65102
- Habitat improvement Re-establish riparian corridors along streams used by the Neosho madtom to reduce stream erosion. Plant willows and other vegetation in minimum 50-foot wide strips on both sides of the stream bank. Exclude livestock with fences and allow the area to naturally revegetate. Water cattle away from the stream by moving watering areas into pastures.
Written by Charlene M. Bessken
Missouri and federal law prohibits the importation, transportation, sale, purchase, taking or possession of animals on the State or Federal lists.
For more information on the Neosho madtom, or to report sightings of this species, contact:
Endangered Species Coordinator or Wildlife Ecologist Missouri Department of Conservation Natural History Division P.O. Box 180 Jefferson City, MO 65102 573/751-4115
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