U.S. & Wildlife Service Flattened Musk depressus

Females lay two clutches of eggs per year, with clutch size ranging from 1-3 eggs. Ovulation occurs in May (1st clutch) and in June (2nd clutch). Eggs in the first clutch are usually laid in May, while eggs in the second clutch are laid in the middle of June through early July. The incubation period is not known, although, one natural nest that contained two eggs took at least 1.5 months to hatch. The nesting season is May through September. While very little is known about nesting preference of the , it is thought that they nest within 100 feet from the river bank in full to partial sun areas such as woodlands and roadsides. photo: CCR Environmental, Inc. photo: Population Status and Distribution Endangered Act is greenish with a dark network The flattened musk turtle is The Endangered Species Act pattern which often breaks up to endemic to the upper Black was passed by Congress in 1973 form spots on the top of the snout. Warrior River system in . to protect species of plants and Stripes on the top and sides of the An evaluation of U.S. Geological in danger of becoming neck, if present, are narrow. There Survey water quality records, extinct. The law provides protection are two barbels on the chin. All collections, field observations, and from direct human threats such as four feet are webbed, and males habitat characterizations, suggest killing and trapping as well as for have thick, long, spine-tipped tails. that only 15 percent of the Black the protection of the ecosystems on which the species depends. Animals Biology and Life History listed as endangered or threatened The flattened musk turtle is by the Department of Interior are believed to live for at least 50 protected by the law on both public years. The turtle is active during and private lands. the months of April to October. Adult flattened musk are primarily On June 11, 1987, the United States nocturnal. While, juveniles are more Fish and Wildlife Service listed the likely than adults to be active at flattened musk turtle offering it day, they are also more active with protection under the Endangered darkness Species Act as a threatened species. The diet consists primarily of Description mollusks and aquatic insects. The flattened musk turtle is a small Adults appear to target and feed aquatic turtle with a distinctly primarily on gastropods (aquatic flattened carapace (upper shell) up snails), clams (including the exotic to 4.7 inches long. The vertebral Asiatic clam) and mussels, while keel (longitudinal ridge) is virtually, juveniles (less than 2.75 inches) if not altogether, lacking. The primarily prey upon softer-bodied carapace is dark brown to orange aquatic insects. with dark bordered seams and is slightly serrated along the back Female flattened musk turtles edge. The plastron (lower shell) reach sexual maturity at 6-8 years, Figure 1: Known range of is pink to yellowish. The head while males require only 4-6 years. flattenedmusk turtle. U.S. Fish & Wildlife Service

Warrior system (streams and substrate exist with suitable food Mount, R.H. 1981. The status of the impoundments) support viable supply. In impounded systems, flattened musk turtle,Sternotherus flatten musk turtle populations. It is the turtle can be found in the minor depressus, Tinkle and Webb. estimated that the turtle may have headwaters and around the margins Report prepared for the U.S. Fish been extirpated from 25-30 percent of lakes. Turtles in lake habitats and Wildlife Service, Atlanta, Georgia. of its former range. The creation of often prefer areas along the bank 119pp. Bankhead Lake and Lewis Smith that have an abundance of shelf like Lake (the largest impoundments rocks. Other factors that indicate Rogers, S.R.H. and K.R. Marion. 2004. in the species’ range) may be good habitat quality for this turtle Assessment of the population status of responsible for a loss of much of include abundant molluscan fauna, the flattened musk turtle Sternotherus( the historic habitat, as water now low silt load and deposits, low depressus) in the Sipsey Fork and covers habitat once preferred by nutrient and bacterial counts, Brushy Creek Branches of Lewis the turtle. However, portions of moderate temperature, and minimal Smith Lake, Alabama. Report prepared Lewis Smith Lake still support pollution. for Alabama Power Co., U.S. Forest populations. Service, and The Nature Conservancy. Threats 19pp. Habitat Siltation has been identified as the Although the flattened musk biggest threat to populations of Schnuelle, K.A. 1997. Demography, turtle is capable of living in a flattened musk turtles. The primary diet and prey availability of the variety of streams and lakes, its source is from coal mine operations, flattened musk turtle, Sternotherus optimum habitat appears to be but runoff from agriculture, depressus. M.S. thesis, Auburn free-flowing large creeks or small forestry and construction also University. 81pp. rivers with vegetated shallows contribute to the siltation problem. about 2-ft deep alternating with Portions of habitat have been U.S. Fish and Wildlife Service. 1990. pools 3.6 to 5-ft deep. These pools eliminated by impoundments, and Flattened Musk Turtle Recovery Plan. have a detectable current and agricultural, residential, and industrial Jackson, Mississippi. 15pp. an abundance of crevices and development. The turtle has also submerged rocks, overlapping flat been threatened by over collecting rocks, or accumulations of boulders. (collectors/pet trade) and disease. Habitats with high amounts of sand are also suitable as long as plenty Literature citations for this fact sheet of bedrock, boulder, and cobble are available upon request.

References Close, D.K. 1982. The reproductive cycle of Sternotherus minor depressus. M.S. thesis, University of Alabama Birmingham. 101pp.

Dodd, C.K. Jr. 1988. Disease and population declines in the flattened musk turtle, Sternotherus depressus. American Midland Naturalist 119:394- 401.

Dodd, C.K. Jr., K.M. Enge, and J.N. Stuart. 1988. Aspects of the biology of the flattened musk turtle, Sternotherus depressus, in northern Alabama. Bulletin of the Florida State Museum. Biological Sciences. 34-1-64.

Marion, K.R., W.A. Cox, and C.H.

photos: CCR Environmental, Inc. Ernst. 1991. Prey of the flattened musk turtle, Sternotherus depressus. Journal of Herpetology 25:385-387.