Spiny softshell turtle (Apalone spinifera) COSEWIC assessment and status report: chapter 3

Species Information

Name and classification

The eastern spiny softshell (Apalone spinifera spinifera) or la tortue-molle à épines is the only one of the six subspecies of Apalone spinifera whose range extends north into Canada. The genus name is derived from apala = soft, and the species name is from spinifer = thorn bearing. Originally classified as Trionyx spiniferus (Lesueur 1827) the name Apalone spinifera has recently been applied to the three American species of softshell turtle (Smith and Smith 1980).

Description

The softshell is a medium to large-sized freshwater turtle. Males can reach a carapace length of up to 21.6 cm. Females can reach up to 54.0 cm and weigh as much as 11.7 kg and are on average more than 1.6 times larger than males (Harding 1997). The carapace is olive to tan in colour, flat, round, keelless, and leathery with inconspicuous, spiny projections present along the anterior edge. The surface of the carapace may be slightly roughened like sandpaper, particularly in juveniles. Adult males retain the juvenile pattern of ocelli, spots, and lines whereas females develop a mottled or blotched pattern that is slightly noticeable even at the time of hatching. The head and limbs are olive to gray, with a pattern of dark spots and yellowish-green stripes. The tubular snout is truncated, with large nostrils, each of which contains a septal ridge; the lips are yellowish with dark spotting, and the jaws are sharp. All four feet are webbed, and the webbing extends up the shank of the hind limbs.

Page details

Date modified: