SMOOTH SOFT-SHELL TURTLE (Apalone mutica), (LE SUEUR, 1827)
Hood County, Lake Grandbury
Polk County, Brazos River
Denton County, Trinity River
Females grow to almost twice the size of males with a carapace length of 7-14 inches (17.8-35.5 cm). Adult males have a carapace length of 5-7 inches (12.7-17.8 cm). The carapace is round and covered in a leathery skin without tubercles or spines. Males retain a more disk shaped carapace while the carapace of mature females is more oval. The outer edges of the carapace are soft especially the posterior portion above the tail. The carapace is olive to orange-brown with a series of dark spots. Adult females often have dark blotches. A thin creamy yellow band beginning just behind the forelimbs encircles the outermost edge of the shell. It is bordered along the inner edge by a thinner dark line. The plastron is white to gray and the ventral coloration of the limbs matches that of the plastron. The color of the top of the head, neck, limbs and tail closely matches the base coloration of the carapace. A creamy yellow line thinly bordered above and below by a darker base coloration is present behind the yellow-orange eye (post orbital stripe) extending along the back of the head to the long neck. In younger specimens this line extends in front of each eye and comes into contact near the base of the nostrils. The head is elongated with leathery lips covering a sharp cusp tubular nostrils that are smooth on the inside and lack any interior septum. The feet are fully webbed and the webbing on the forefeet reaches just beyond the elbow. The limbs are covered in dark spots.
Asides from geographic distribution, very little is known about the ecology and natural history of this species in Texas