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Canadian Amphibian and Reptile Conservation Network - Réseau Canadien de 
Conservation des Amphibiens et des Reptiles

Apalone spinifera
Spiny Softshell / Tortue-molle à épines


Spiny Softshell

Description
The Spiny Softshell is distinctive in being our only freshwater turtle with a flexible, leathery carapace. It is a large turtle reaching up to 54 cm carapace length although males are only half this size. The carapace is rough and has small spiny projections at the front edge. It is olive to tan with dark blotches. The plastron lacks a hinge and is white or yellow. The snout is distinctively tubular.

Confusing Species
With its soft, leathery carapace, the Spiny Softshell cannot be easily confused with any other species in Canada.

Distribution
The distribution in Canada is limited to southwestern Québec and southwestern Ontario. It is widely distributed in the eastern United States as far south as Texas and into Mexico. There are some disjunct populations in the west.

Habitat
Spiny Softshells are generally found in rivers with soft bottoms, aquatic vegetation and sandbars or mudflats. They are occasionally found in lakes or impoundments.

Reproduction
Females may take more than 10 years to mature in Canada. Mating occurs in spring, usually in deep water. Nesting occurs in June and July in sandy areas. Females produce two clutches of eggs each year in the southern US, although they may only nest once in Canada. Up to 39 eggs are laid, although the usual number is less than half that. Unlike most species of turtles, the sex of hatchlings is independent of incubation temperature. Eggs hatch in late summer or fall and the young are 3-4 cm long.

Natural History
Spiny Softshells are mainly aquatic, although they do frequently bask along the banks of streams. Individuals will bask communally. They are aggressive when threatened and should not be handled. Females may even squirt blood from their eyes when handled. They feed primarily on insects, fish and crayfish but may eat vegetation. Spiny Softshells can get almost half their oxygen by breathing through their skin while underwater. Some individuals will move up to 30 km along a stream over the course of a summer. Spiny Softshells can live for over 25 years.

Conservation Concerns
Spiny Softshells have historically been collected for food and their numbers have been reduced. Some are also accidentally caught on fish hooks. Great care must be taken to remove them from the hooks without harm to either the turtle or the fisher. They are currently designated Threatened in Canada by COSEWIC.