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Eastern Spiny Softshell Turtle

Status: Endangered

Spiny softshell turtle © Scott Gillingwater

Characteristics

The eastern spiny softshell (Apalone spinifera spinifera), subspecies of the spiny softshell (A. spinifera), is Ontario’s only turtle with a flexible, leathery carapace (upper shell) and the only species in the province that can attain a size comparable to that of the snapping turtle.

Ontario’s most peculiar looking turtle, the spiny softshell has a long snout and a leathery carapace with small spiny projections at the front edge. The carapace is olive-grey, brownish or tan, and its edges are yellow with a black outline. The carapace of males and juveniles has large spots with a dark outline, whereas the spots on the carapace of females are smaller and are not outlined. The legs and head are dark green or grey with dark patterning, and along each side of the head is a distinct yellow stripe outlined in black. The carapace of females of this large turtle may reach 46 centimetres in length, and that of males may reach a length of about 24 centimetres.

Other names: spiny softshell turtle, Trionyx spiniferus, Trionyx spiniferus spiniferus, Trionyx ferox spinifera, Amyda ferox spinifera

Spiny softshell turtle © Joe Crowley

Similar Species

With its soft, leathery carapace and pointy snout, the spiny softshell is unlike any other turtle in Ontario.

Habitat

Eastern spiny softshells are generally found in rivers with soft bottoms, aquatic vegetation and sandbars or mudflats but also occasionally in lakes or impoundments. These turtles require gravelly or sandy areas for nesting and deep water for hibernating. They are primarily aquatic and are never far from water, in which they hide from prey and predators. Softshells regularly bask along the riverbanks or on rocks.

Spiny softshell turtle © Scott Gillingwater

Biology

In Canada, females of this species may take more than 12 to 15 years to mature. Eastern spiny softshells mate in spring, usually in deep water, and nest in June and July in open sandy or gravelly areas close to water. Females lay up to 36 eggs, though the typical clutch size is around 20 to 26. Unlike in most turtle species, in the spiny softshell the gender of the hatchlings is independent of incubation temperature. Eggs hatch in late summer or fall.

Spiny softshells feed primarily on insects and crayfish but may also eat molluscs, fish, amphibians, carrion and vegetation. These turtles can get almost half the oxygen they require by breathing through their skin while in water, which allows them to stay under water for up to five hours. Individuals may move up to 30 kilometres over the course of a summer, and daily movements exceeding four to seven kilometres have been observed. Spiny softshells can live for over 50 years.

Spiny softshell turtle hatchling © Scott Gillingwater

Threats and Trends

Much of the historic habitat of the spiny softshell has been lost, and the degradation and fragmentation of what little habitat remains, primarily as a result of shoreline development, threatens the persistence of this species in Ontario.

The causes of recently observed poor nesting success are the subject of ongoing studies and may include environmental contaminants, sacrophagid fly infestations and the disturbance of nesting sites by both humans and predators. Injury and death due to boat propellers and fishing also threaten this species.

Spiny softshell turtle hatchling © Joe Crowley

Current Status and Protection

The spiny softshell turtle (of which the eastern spiny softshell turtle is a subspecies) is currently listed as Endangered under both the federal Species at Risk Act and the Ontario Endangered Species Act, 2007. The species has also been designated as a Specially Protected Reptile under the Ontario Fish and Wildlife Conservation Act. These acts offer some protection to individuals and their habitat. The International Union for Conservation of Nature has not yet assessed the global status of the eastern spiny softshell, but lists the spiny softshell as Least Concern. The spiny softshell’s status was confirmed in August 2010.

Learn more about reptile and amphibian conservation and what you can do to help these species on our Reptile and Amphibian Stewardship page.

Spiny softshell turtle © Scott Gillingwater

What You Can Do

Eastern spiny softshell turtle © Ryan Wolfe