Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Softshell Turtles

Apalone (formerly Trionyx)

©1995 Melissa Kaplan

These New World species range from Canada, through the U.S. east of the Rockies, down into northern Mexico. softshelled species are also found in northern Africa, through Israel up into Turkey, in the Amur region in the former USSR, and from China and Korea down through southeast Asia, including species introduced into Hawaii.

The most common in the pet trade and captivity are the smooth softshell (Apalone mutica), the Florida softshells (A. ferox) and the eastern spiny softshell turtles (A. spinifera spp.), whose natural range extends from southern Ontario and Quebec, through the northern U.S. from Montana, Wyoming and Colorado east to New York, Vermont, and south to Georgia and into Florida and Mexico.

A. mutica are pale-medium brown, the males with more dark spotting than the females. The A. spinifera spp. are medium brown with darker spots and blotches on their shell. A. ferox hatchlings have a dark brownish carapace with blotching markings on the shell; these markings tend to blend out into a more uniform dark brown color over the carapace. The hatchlings also have a yellowish-orange stripe around the outside of the shell and along the face. On the A. spinifera, the markings are fainter, and the carapace's leading edge is lined with small spiky projections.

The softshells truly have soft shells: in fact, their shells are mostly thickened skin. As such they are much more vulnerable to injuries from rocks and bites than are other hard-shelled turtles. They are highly aquatic, spending most of their time under water, often buried under the sandy or muddy river or lake bottoms with only their long probiscus topping the surface. Like many aquatic amphibians, softshells respire through their skin as well, thus are particularly susceptible to impurities in the water.

Softshells are found in a variety of waters: lakes, ponds, streams, rivers, even ditches. Some species are quite aggressive. They are carnivores and as such are able to render some very painful bites should they be so inclined. In some parts of their range, they are an important food item, especially the larger Asian specimens which may reach 36" in length.

Due to their aggressive tendencies, especially if overcrowded, they should be kept single or in pairs. Pairs should be monitored closely to assure that one is not attacking the other; bite marks on the fleshy carapace or plastron are one indicator, and severe injuries have been inflected on their sensitive noses, as well, from aggressive conspecifics.

Softshells are very shy around humans, and often will not come out much when any are around. Food intake must be monitored by looking to see that food offered disappears and that feces appear regularly. When kept in a home they should be in a low traffic, low noise area.

Aquaria should be established with a thick enough layer of clean fine sand at the bottom to enable the turtle to completely bury itself. The sand should be covered with enough water to completely cover the turtle but not so deep that it cannot extend its neck and get its head above the surface of the water. Water must be kept very clean. softshells are more susceptible to impurities, whether feces or toxins or rotting food, in their water than are other aquatic turtle species.

Like most aquatic turtles, softshells must be able to haul themselves out of the water onto a warm and dry basking area. Basking temperatures of 85 F (warmer for the Florida softshells) are required during the day. Water temperatures can range from 70-80 degrees. Basking heat should be provided by an overhead incandescent light. Special UVB fluorescent lighting is not necessary.

In the wild, softshells feed primarily on invertebrates and crayfish, sometimes found scavenging on fish, as well as a variety of aquatic vegetation. Some larger species snag ducks and other small aquatic birds by grabbing them from below. Other species may feed on frogs, tadpoles, mudpuppies, snails, molluscs, and worms. In captivity, they can be fed on meats (cook chicken first!) and dog food; turtles greater than 8 inches carapace length should only get low fat/low protein dog foods. An assortment of feeder fish and invertebrates may be offered as well.

Additional Species/Subspecies
Apalone spinifera. aspera. Gulf Coast Spiny Softshell
A. s. emoryi. Texas Spiny Softshell
A. s. guadalupensis. Guadalupe Spiny Softshell
A. s. hartwegi. Western Spiny Softshell
A. s. pallida. Pallid Spiny Softshell
A. s. spinifera. Eastern Spiny Softshell
Trionyx axenaria. China
T. triunguis. Africa

Sources

Breen, J. F. Encyclopedia of Reptiles and Amphibians. 1974. TFH Publications.

Conant, R. Collins, Joseph T., Reptiles & Amphibians Eastern & Central North America. 1991. Houghton Mifflin Company.

TIGR Reptile Database: Trionychinae

Ernst, C.H., Barbour, R. W., Lovich J.E. Turtles of the United States & Canada. 1994. Smithsonian Institutional Press.

Obst, F. J., et al. The Completely Illustrated Atlas of Reptiles and Amphibians for the Terrarium. 1988. TFH Publications.

Pritchard, P. C. H. Encyclopedia of Turtles. 1979. TFH Publications.

Wilke, H. Turtles. 1990/1991. Barron's Educational Series.

Special thanks to Charlie Green.

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