Apalone ferox
Florida softshell turtle

Apalone ferox is found only in the southeastern United States, from southern South Carolina west to Mobile Bay, Alabama, and south through the Florida peninsula. It is apparently not found in the Florida Keys, with the exception of a colony on Big Pine Key, where it was possibly introduced. Apalone ferox can be common over much of its range and sometimes thrives in urbanized areas. (Ashton and Ashton, 1985; Ernst, Lovich, and Barbour, 1994; Meylan, 2006; Pritchard, 1979)

Florida softshell turtles are highly aquatic and are found in freshwater ponds, lakes, swamps, marshes, and sometimes drainage ditches. They are generally found in water bodies with muddy or sandy bottoms. Occasionally they are found in brackish waters near the mouths of streams. They can also be found in the quieter portions of rivers and streams and may sometimes occur sympatrically with spiny softshell turtles, Apalone spinifera. However Apalone spinifera prefers aquatic habitats with moving water, so is more common where A. ferox is scarce. (Bonin, Devaux, and Dupré, 2006; Conant and Collins, 1998; Ernst, Lovich, and Barbour, 1994; Meylan, 2006)

Adult Florida softshell turtles have bumpy, leathery, oblong carapaces with dark brown to olive green colors and a gray to white plastron. Both the carapace and plastron lack scutes. The carapace has longitudinal rows of indentations and raised areas on the dorsal surface. On the thickened edge of the anterior portion of the carapace there is a series of wide, short tubercles in a crescent shape. Short tubercles also cover the sides of the forelimbs. Carapace tubercles on Florida softshell turtles are flattened hemispheres instead of the cone-shaped projections seen in the sympatric Gulf Coast Softshell, Apalone spinifera aspera. Bones underlying the plastron can sometimes be seen through the leathery skin covering. The carapace occasionally has faint irregular blotches left over from the juvenile pattern. A yellow to red stripe sometimes is present from each eye to the base of the lower jaw. The tubular, pig-like nose is truncated with each nostril having a lateral ridge projecting from the nasal septum. All four feet are webbed; webbing extends up the shank of the hind legs. This species is bulky and the largest of all New World trionychids. Sexual dimorphism is marked, with females much larger than males. Adult females are usually between 28 and 63 centimeters in carapace length (record 73.6 cm), with short tails that barely extend beyond the carapace rim. Males are usually between 15 and 33 centimeters in carapace length, with long, thick tails with the anal vent well beyond the carapace rim. (Ashton and Ashton, 1985; Bartlett and Bartlett, 2006; Conant and Collins, 1998; Ernst, Lovich, and Barbour, 1994; Meylan, 2006; Pritchard, 1979)

Juveniles have more contrasting color patterns than adults. The carapace is olive, tan, or light brown with darker brown or black spots and a yellow marginal rim. The plastron is dark purplish gray to black. The snout and neck are marked with yellow or orange stripes. The snout is marked with a Y shaped figure on the anterior edge, reaching from each eye down the middle of the nose. (Ashton and Ashton, 1985; Conant and Collins, 1998; Ernst, Lovich, and Barbour, 1994; Meylan, 2006; Pritchard, 1979)

Sex determination is genetic, with no influence from nest temperature. Hatchlings and juveniles are shaped much like adults, although their color darkens with age. Growth slows with maturity. (Ernst, Lovich, and Barbour, 1994; Meylan, 2006)

The average and maximum lifespan of Apalone ferox in the wild appears to be unknown. Captives often live over 20 years and a specimen at the National Zoological Park (Washington D.C.) reportedly lived 36 years and 8 months. (Ernst, Lovich, and Barbour, 1994; Slavens, 1999)

Florida softshell turtles are almost entirely aquatic, but can move fast both in water and on land. They are commonly seen basking in the sun on logs or muddy banks or in floating vegetation. They also spend much of their time buried in the sand or soft mud of their habitats. Florida softshell turtles are known for being extremely aggressive and will snap or scratch at anything within reach with their sharp jaws and claws if they are handled or feel threatened. The specific name "ferox" means "ferocious." Apalone ferox can also excrete a foul smelling musk to warn away predators. Other softshell turtle species display occasional intraspecific aggression and large animals may dominate smaller ones in captivity. (Ashton and Ashton, 1985; Ernst, Lovich, and Barbour, 1994; Meylan, 2006)

Perhaps more than other softshell turtle species, Florida softshell turtles are willing to move overland to seek better conditions, sometimes leading to mortality on roads. Florida softshell turtles can tolerate the high temperatures found in their shallow water habitats. Maximum tolerated temperatures reported for this species ranged from 38.9 to 42.3 degrees C. These turtles can be active all year when temperatures are mild, but become inactive during cold weather. In the northern part of their range they will hibernate during the coldest part of the winter. Florida softshell turtles tolerate long submergence times in water, especially when they are inactive and the water is cold and high in oxygen. Gas exchange can occur through the skin and perhaps through cloacal membranes. (Ernst, Lovich, and Barbour, 1994; Meylan, 2006)

Home Range

Little seems to be known about home range or territoriality in this species. (Ernst, Lovich, and Barbour, 1994)

Little has been reported about communication and perception in Florida softshell turtles. Another American softshell turtle, Apalone spinifera, was reported to have some orientation ability for migratory movement; orientation seemed to be dependent on solar (sun) cues coupled with an internal time sense. Hatchlings oriented towards light and (unseen) water. Color vision seems likely in softshell turtles. (Ernst, Lovich, and Barbour, 1994)

Florida softshell turtles are mostly carnivorous, and both predaceous and scavenging. Typical foods include snails, insects, crustaceans, fish, amphibians, small turtles (Pseudemys, Sternotherus), snakes (Nerodia, Regina), and occasional aquatic birds. Vegetation and seeds sometimes occur in stomach contents. Small Florida softshell turtles eat many insects, but increase the number of snails and fish in the diet as they grow. Males may consume more snails, clams, and palm seeds than females, which may prefer fish or larger items. Florida softshell turtles conceal themselves in the sand at the bottom of lakes and ambush passing schools of fish. Perhaps because they eat carrion, Florida softshell turtles may be be more effected by pesticides than other aquatic turtles. (Bonin, Devaux, and Dupré, 2006; Ernst, Lovich, and Barbour, 1994; Meylan, 2006)

Crows, spotted skunks, American black bears, raccoons, and red foxes all rob Florida softshell turtle nests. Large fish, turtles (Chelydra, Macroclemys), snakes (Agkistrodon, Nerodia), raptorial birds (Everglades kites, eagles) wading birds (herons and egrets) and mammals (armadillos, striped skunks, and otters) eat young turtles, and alligators feed on Florida softshell turtles of all sizes. Humans are the greatest predator of all - people exploit these turtles for food and pets, destroy and pollute habitat, and cause highway mortality. (Bonin, Devaux, and Dupré, 2006; Ernst, Lovich, and Barbour, 1994; Meylan, 2006)

Florida softshell turtles play a role in the aquatic ecosystem both as predators and as scavengers, and in turn provide food (as eggs and post-hatching turtles) for other predators. Young Apalone ferox are prone to bacterial and fungal skin problems; these problems occur in both wild and captive animals and populations. Little is known about parasites in Apalone ferox; they can harbor leeches, and Foster et al. (1998) found eight helminth species in Florida softshell turtle obtained from a commercial processor. The most prevalent helminths were Spiroxys amydae (80%), Cephalogonimus vesicaudus (80%), Vasotrema robustum (76%) and Proteocephalus (63%). (Bartlett and Earle-Bridges, 1996; Ernst, Lovich, and Barbour, 1994; Foster et al., 1998)

Florida softshell turtles are generally harmless to human interests; they do eat fish and occasionally young water birds, but no significant effects on prey populations have been reported.Florida softshell turtles are aggressive and will bite if handled or restrained, but are probably harmless to humans if left alone. (Bartlett and Bartlett, 2006; Ernst, Lovich, and Barbour, 1994)

Florida softshell turtles are harvested in large numbers for the food trade, both for domestic consumption and, increasingly, to supply Asian markets. Between July 1990 and July 1991, 3600 softshell turtles were purchased for meat in south Florida. Today there are breeding centers in southern Florida to raise turtles for Chinese markets (Bonin et al., 2006), but wild turtles are often taken to resupply breeding farms. Apalone ferox is the most heavily harvested turtle species in Florida. (Bonin, Devaux, and Dupré, 2006; Ernst, Lovich, and Barbour, 1994; Meylan, 2006; Moll and Moll, 2004)

Florida softshell turtles remain common in many parts of their range, but populations are locally threatened due to habitat destruction and heavy harvesting. Despite large numbers removed from the wild in some places, Florida softshell turtles remain common in refuge areas and other areas less subject to harvest; their dispersal abilities may allow them to repopulate over-harvested or isolated habitats. Softshell turtles (Apalone) are sensitive to rotenone, a poison often used to collect and survey fish for population studies. Florida softshell turtles are subject to harvest regulations in states where they occur, but are not yet considered to be endangered or threatened on any Federal or State list. They are a Species of Concern in South Carolina. Unusual among turtles in general, Florida softshell turtles may be able to sustain a regulated harvest, and thus take pressure off more sensitive species (Meylan 2006). (Ernst, Lovich, and Barbour, 1994; Meylan, 2006)