With fifteen genera and thirty species, the family Trionychidae occurs throughout most of the world. These distinctive turtles have a range that includes North America, Africa, southern and eastern Asia, and the East Indies to New Guinea. Fossil records from the late Jurassic Period provide evidence that this family’s distribution once included Europe and South America.
One genus and four species comprise the soft-shelled turtle diversity in North America. In general, North American soft-shelled turtles are moderately sized. The Florida soft-shelled turtle (Apalone ferox) attains the largest size at 25 inches (63 centimeters). This species has a distribution that includes southern South Carolina, central Georgia, eastern Alabama, and Florida.
The smooth soft-shelled turtle (Apalone mutica) is one of two species inhabiting the central United States and reaches 14 inches (35 centimeters) in carapace length. Unlike its cogener, the spiny soft-shelled turtle (A. spinifera), this species lacks tubercles on the anterior portion of its carapace.
The spiny soft-shelled turtle has the widest range of all the North American soft-shelled turtles. This species has a geographic distribution that includes southern Ontario and Quebec, Canada, to northern Florida westward to Montana and southeastern California. It also occurs south of the Rio Grande in Juarez, Coahuila, Nuevo Leon, and Tamaulipas, Mexico.
Two species of soft shell turtle occur in Texas.
The smooth soft shell turtle (Apalone mutica)
*The Florida soft shell turtle (Apalone ferox): Although Bartlett and Bartlett, 1999 include this species as a component of Texas herpetofauna based on supposed specimens "known only from ponds on the campus of the University of Texas at Arlington". After 12 years of catching and watching turtles on the UT Arlington campus I have never seen a specimen. The inclusion of this species in Bartlett's 1999 Texas field guide is most likely due to a misidentification of a large female spiny soft shell that has resided in Trading House Creek for 20 + years. Also there has been no voucher specimen or photograph provided to substantiate the claim of this species occurring in Texas. Furthermore there are no ponds on the UT Arlington campus.
