Eastern Spiny Softshell

Apalone spinifera spinifera
Family

Trionychidae (softshells) in the order Testudines (turtles)

Description

The eastern spiny softshell has small bumps or spines on the front of the upper shell and a small ridge on each side of the snout. Shell color varies with age and sex. Males and young turtles have an olive or grayish-tan upper shell with small black dots and circles and a black line along the margin. Adult females have a dark olive or tan upper shell with brown and gray blotches. The lower shell is a plain cream color. Head and limbs are normally tan or olive with small brown or black spots. A yellow stripe, bordered by dark brown, runs from the snout through the eye and along the side of the head; another light stripe runs from the jaw onto the neck.

Though they lack a hard shell, softshells defend themselves with strong jaws and by being fast swimmers. They also use their strong, sharp claws to defend themselves when picked up. They should be handled very carefully to avoid injury.

Similar species: The western spiny softshell subspecies (A. spinifera hartwegi) has small (not large) circular markings along the center of the upper shell. It occurs statewide. The midland smooth softshell (A. mutica mutica) lacks bumps or spines at the front of the upper shell.

Size

Upper shell length: 5 to 9 ¼ inches (males); 7 to 17 inches (females).

Eastern Spiny Softshell Turtle

Eastern Spiny Softshell Turtle
Eastern Spiny Softshell Turtle

Eastern Spiny Softshell

a flat turtle with a pointed snout walks through gravel. Part of its shell is covered in dust.
Eastern spiny softshell turtle in Prairie State Park
Habitat and conservation

This species inhabits large rivers and streams, plus lakes and large ponds. A muddy or sandy bottom is preferred. Like other softshells, this species is well equipped for an aquatic life, with a flat, round, smooth upper shell covered with skin; webbed toes; and a long, tubular snout that functions like a snorkel.

Foods

It eats a variety of aquatic animals, including crayfish, insects, snails, tadpoles, and fish, but is not a threat to Missouri’s game fish populations.

image of Eastern Spiny Softshell Distribution Map
Distribution in Missouri

The eastern spiny softshell is found in the eastern part of the state, but it intergrades and eventually is replaced by the western spiny softshell (Apalone spinifera hartwegi) in central and western Missouri.

Status

To maintain healthy populations of this interesting reptile, harvest is controlled by state regulations. Consult the most recent Wildlife Code of Missouri for current regulations.

Life cycle

This species is active from March to October. To escape the cold temperatures of winter, it digs 2–4 inches into the mud at the bottom of a river or lake. Courtship and mating occur in April and May, and eggs are laid from late May through July. Females lay 4–32 eggs in a nest on a sand or gravel bar, or a sandy opening near water. These hatch from late August to October. The shells of young turtles are about 1¼ to 1½ inches long.

Human connections

As a game species with delicious meat, softshell turtles are economically valuable as a human food source. Make sure you know the current regulations regarding their harvest. Spiny softshells are defensive and have strong jaws. They will try to bite when captured.

Ecosystem connections

Although softshells may prey upon nearly any species of fish, there is no evidence to show that they harm a fish population in natural waters. Like other components of our native aquatic ecosystems, they contribute to the balance of nature.