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.
Range birth mass: 8.4 to 11 g.
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)