About Kinosternon oaxacae Berry & Iverson, 1980
This species, the Oaxaca mud turtle (Kinosternon oaxacae), exhibits distinct size differences between sexes. Males grow to a carapace length of roughly 160 mm (6 in), while females are slightly smaller. Males reach sexual maturity at a shell length of approximately 113 to 125 mm, when they are between 7 and 10 years old. Females reach maturity at a shell length of around 115 mm, when they are between 8 and 9 years old. The carapace is slightly depressed, with three distinctive longitudinal keels; its width is about 60% of its length, and 35% of its height. Carapace color ranges from dark brown to blackish, or a mottled combination of the two. In lighter-colored individuals, the shell seams are darker. The plastron is relatively narrow, measuring about two-thirds the width of the carapace. It is concave in males, and nearly flat in females. Plastron color is yellowish or pale brown, with darker seams. This turtle has a V-shaped or bell-shaped rostral shield. The head is dark brown or black, mottled with cream; it may sometimes be reticulated, but it is never striped. The underside of the head and throat are cream, and three or four pairs of barbel are present on the chin and throat. The upper surfaces of the limbs are grey or brown, and the lower surfaces are cream. The tail is uniformly greyish brown. This mud turtle is endemic to Mexico. It occurs only in the Mexican states of Guerrero and Oaxaca, where it is restricted to the drainage basins of the Rio Colotepec and the Rio Tonameca. It inhabits altitudes between roughly 100 and 800 m (300 and 2,600 ft). Its preferred habitats are marshes, muddy pools, and other still, turbid water bodies. It occasionally occurs in rivers, and is sometimes found on the coastal plain after being washed downstream by flooding rivers. The diet of the Oaxaca mud turtle is mostly made up of plant material, but it also eats small animals including tadpoles, shrimps, beetles, and fish. Unlike other species in the genus Kinosternon, this species is an opportunistic feeder that consumes both plant matter and small animals. These turtles are most active during the rainy season, which runs from June to October. Breeding likely occurs in July, and eggs hatch after the rains end. Young turtles grow slowly, taking between 7 and 10 years to reach maturity.
