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.
Communication Channels: visual
Perception Channels: visual ; tactile ; chemical
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).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: no special status
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.
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.
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.
Positive Impacts: pet trade ; food
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%).
Commensal/Parasitic Species:
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.
Animal Foods: birds; amphibians; reptiles; fish; carrion ; insects; mollusks; terrestrial worms; aquatic crustaceans
Plant Foods: leaves; seeds, grains, and nuts; algae
Primary Diet: carnivore (Piscivore , Insectivore , Eats non-insect arthropods, Molluscivore , Scavenger )
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.
Biogeographic Regions: nearctic (Native )
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.
Habitat Regions: temperate ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams; brackish water
Wetlands: marsh ; swamp
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.
Range lifespan
Status: captivity: 36.75 (high) years.
Typical lifespan
Status: captivity: 20 (high) years.
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.
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.
Range mass: 43.6 (high) kg.
Range length: 15 to 73.6 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: female larger; sexes shaped differently
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.
Known Predators:
Anti-predator Adaptations: cryptic
Most (more than 90%) of mature females appear to breed every year. In Florida females carried eggs in the oviduct from March through July; males were found to produce sperm in fall (September to October) and mating probably occurs in spring (March to May). Although Florida softshell turtles are fairly common, courtship and mating have not been described in the literature.
Mating System: polygynandrous (promiscuous)
Nesting takes place between mid March and July in central and southern Florida, and in June and July further north. There is a possibility for females to nest 2 to 7 times in one season. Florida softshell turtles may produce more eggs per year (up to 225) than any reptile species other than South American river turtles (Podocnemis expansa), some of the marine turtles, or some Asian softshell species. Females emerge from the water in daytime to nest in sand or well drained soil, but sometimes use newly constructed alligator nests. This habit may take advantage of the female alligator's defense of her nest against predators. The nest is dug with the hind feet and may be up to 14 cm deep and 10 cm in diameter. The female may expel cloacal water on the nest site, perhaps to facilitate excavation. After nesting, females often scratch and churn the ground as they move away from the nest. This behavior may draw predators away from the actual nest. From 9 to 24 brittle, white, spherical eggs are laid per clutch; eggs have an average mass of about 14 grams and range from 24 to 33 mm in diameter. The incubation period is between 56 and 80 days, with the hatchlings averaging 9.7 g and ranging from about 29 to 44 mm in carapace length. Florida softshell turtles are sexually dimorphic with females exceeding the largest male's size by three to five times.
The minimum size for sexual maturity in males is about 0.7 kg and 15.1 cm in plastron length (PL) Some may mature at as small a size as 12 cm PL. For females, the minimum size for sexual maturity is about 20 cm in plastron length. However most females may mature at about 24 cm PL, and some may need to reach 30 cm PL before reproducing.
Breeding interval: Females can lay up to 7 clutches per year between February and August.
Breeding season: Breeding occurs from February to August, although most breeding occurs from March to July.
Range number of offspring: 9 to 40.
Average number of offspring: 26.
Range gestation period: 56 to 80 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous ; sperm-storing
Energy is concentrated by the female in the yolk of her eggs, and the production of several egg clutches, along with the nesting process itself, is energetically demanding. Once the female leaves the nest site, there is no further parental investment in the eggs or young.
Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female)
The Florida softshell turtle (Apalone ferox) is a species of turtle in the family Trionychidae. The species is native to the Southeastern United States.[4][5]
The Florida softshell turtle is found primarily in the state of Florida, but it also ranges to southern sections of Alabama, Georgia, and South Carolina.[6] It is the only species of softshell turtle whose range spans the entire Florida peninsula.[7] Of the three species in the genus Apalone, the Florida softshell turtle occupies the smallest geographic range.
The Florida softshell turtle is a widespread species and occupies almost every freshwater habitat, even tolerating some brackish environments; however, it is not often found in water with strong currents, preferring habitats with slow-moving or still water. These different habitats include swamps, lakes, marshes, wet prairies, small rivers, creeks, and even ponds formed in man-made ditches or sinkholes.[8][9][10][11]
The Florida softshell turtle is a large turtle with a flattened, pancake-like body, a long neck, an elongated head with a long snorkel-like nose, and large webbed feet, each with three claws. While most turtles have hard shells composed of scutes, the Florida softshell turtle has a cartilaginous carapace covered in leathery skin. Ranging from olive green to dark brown, it has the darkest coloration of all the softshell species that inhabit Florida (other species include Apalone mutica calvata and Apalone spinifera aspera). It is also characterized by a white or cream-colored underside.[12][7] This color pattern is known as countershading and is a form of camouflage to conceal turtles from potential predators.[13] It is also the largest species of softshell turtle found in Florida and all of North America, ranging from 15 to 76 cm (5.9 to 29.9 in) in straight-line carapace length.[12] The Florida softshell turtle also exhibits significant sexual size dimorphism. Adult females are often 3-5 times larger than males. Males have a carapace length and body weight averaging about 35 cm (14 in) and 2.68 kg (5.9 lb) respectively. Nesting adult females were found to average 6.65 kg (14.7 lb) in weight and measure 40.1 cm (15.8 in) in carapace length, with the record weight documented at 43.6 kg (96 lb).[14][4] However, males tend to have longer tails than their female counterparts (3 cm longer than a female of the same size). Hatchlings have a lighter carapace with yellow and orange markings and a carapacial rim. Stripes in the same color are also found on the face and neck. The plastron of hatchlings is generally dark in color. As the turtle ages, these colors fade and are lost, resulting in the dark-brown coloration characteristic of adults.[12][7]
The Florida softshell turtle is almost entirely aquatic, only emerging from the water to bask or to lay eggs.[12] In the water, it prefers to bury itself in the sandy/muddy substrate. Like all softshells, it is very fast-moving in water and on land.[12] While this species is omnivorous, its diet consists largely of meat, consuming mainly fish, insects, crustaceans, frogs and mollusks. It may also scavenge.[1]
The reproductive cycle of male Florida softshell turtles follows a postnuptial pattern, with a cycle of spring mating followed by spermatogenesis in the fall. The male will produce sperm during the fall and store that sperm in the epididymides through the winter. This stored sperm can then be utilized for copulation during the following spring mating season. Evidence suggests that they undergo spermatogenesis every year. Males of this species reach sexual maturity at small sizes (below 0.7 kg), allowing them to begin reproducing quickly following birth. This implies that some males may be able to reproduce as young as two years of age.[14]
While males consistently reach sexual maturity at small sizes, that size is larger and more variable in females. Some may reach maturity at a plastron length of 24 cm, and others may not mature until they reach a length closer to 30 cm. The onset of sexual maturity will occur anywhere from 5 – 8 years of age. The female nesting season can range anywhere from early April to early August, and incubation lasts an average of 60 – 90 days. In a study examining female reproduction, almost 10% of the females examined in a single breeding season showed signs of inactive ovaries, implying that, unlike males, females may not possess the ability to reproduce every year. Florida softshell females have the ability to produce an average of 4 – 5 egg clutches in a single breeding season, potentially producing a new clutch every three weeks. Florida softshell turtles have one of the highest annual egg production rates of any reptile. The study previously mentioned showed an average of over 20 eggs per clutch, with the largest clutch containing 38 eggs.[7][4]
With a primarily carnivorous diet, adult Florida softshell turtles function as major predators in their aquatic ecosystems. Sitting high on the trophic scale, they generally function as secondary or tertiary consumers.[15] However, alligators have been known to prey on the adults of the Florida softshell turtle, and raptors may take juveniles. Nest predators include the fish crow, foxes, raccoons, skunks, and river otters.[1][16] At various lakes across the state of Florida (Okeechobee, Apopka, Griffin, and Jesup) scientists have observed Florida softshell females, as well as other turtle species (Pseudemys nelsoni, Kinosternon sp., and Sternotherus odoratus) laying their eggs in American alligator (Alligator mississippiensis) nests during the summer months. While the turtles may utilize vacant nests more often, they have also been known to lay eggs in occupied alligator nests. They use these nests more often in areas with limited nesting habitats and/or during years with heavier precipitation when high water levels and flooding further reduce the number of suitable nesting sites.[17] Despite the Florida softshell's use of alligator nests, studies have shown the highest abundance of Florida softshell turtles to persist in lakes with little to no alligators as well as high primary productivity, suggesting a combination of top-down and bottom-up influences on Florida softshell turtle populations.[18]
The Florida softshell turtle is common throughout Florida and other parts of its range. However, wild populations are subject to various threats at the hands of humans. Some of these threats include commercial harvesting for meat, harvesting for the pet trade, and roadway mortalities.[19][20]
The Florida softshell turtle is carnivorous with its main diet consisting of small snails and fishes. It also preys upon amphibians, insects, mollusks, and some waterfowl. The Florida softshell turtle will hunt, chase, and scavenge for prey.[5]
The Florida softshell turtle (Apalone ferox) is a species of turtle in the family Trionychidae. The species is native to the Southeastern United States.
_at_Lake_Woodruff_-_Flickr_-_Andrea_Westmoreland.jpg)
.jpg)
