Razor back musk turtle (Sternotherus carinatus)
IDENTIFICATION:  4-5inches (10-12.5 cm)   The grayish brown to tan carapace is oval in dorsal perspective.   In lateral perspective the carapace is highly domed with each side shaply sloping at an angle from the keeled midline of the carapace. The plastron varies in coloration from yellowish to brown.  A weakly developed plastral hinge is present in younger specimens but may be relatively absent among older specimens as the fleshy areas between the plastral scutes increases with age.  A gular scute is absent from the plastron.  The flesh between the plastral elements ranges in color from that of the rest of the fleshy parts to having suffusions of orange or pink.   Olive to dark spots are present on the head and tail.  Small vertical streaks are present on the tan colored cusp of the mouth.  Two barbels are present on the chin.

BEHAVIOR AND ECOLOGY: This small turtle inhabits  bodies of freshwater with soft bottoms and aquatic vegetation.  While common musk turtles seem to prefer still to slow moving bodies of water they have been found in numerous streams with swift currents.  Populations from southern localities may remain active throughout most of the year.  Females usually lay between 2-5  elliptical brittle-shelled eggs per clutch. 
This species is primarilly aquatic but spends more time basking than any other species of musk turtle.  Given the amount of time spent in the water, some specimens may bear  healthy growth of algae on their shells. Razorback musk turtles are omnivores known to consume a wide range of crustaceans, insects, mollusk, amphibians, carion and aquatic vegetation.

PREDATORS AND DEFENSE:  These small turtles are susceptible to various predators ranging from predaceous diving beeetles, (Family Dystictidae), large mouth bass (Micropterus sp.), bullfrogs (Rana catesbiana), kingsnakes (Lampropeltis getula), cottonmouths (Agkistrodon piscivorous), alligators (Alligator missippiensis), crows (Corvus sp.), bald eagles (Haliaeetus leucocephalus), hawks (Buteo sp.), skunks (Mephitis sp.) and racoons (Procyon).  However, humans are probably responsible for more casualties than all of the other predators combined.  Whenever hooked by a fisherman this species is usually killed.  However, pollution and habitat loss in the form of drained wetlands poses the greatest threat.i

LONGEVITY:  A private keeper maintained a captive specimen for 29 years and 4 months.

GEOGRAPHIC DISTRIBUTION: Sternotherus carinatus  occupies a geographic range that includes south central Mississippi to the Gulf of  Mexic, southeastern Oklahoma and central Arkansas southward to eastern and central Texas .