THE FEMALE REPRODUCTIVE-CYCLE OF THE FLORIDA SOFTSHELL TURTLE (APALONE FEROX)

This study of the female reproductive cycle of Apalone ferox in south Florida was based on 220 reproductive tracts salvaged from females but chered for meat Some females mature at sizes as small as 24 cm plastro n length (PL; ca. 31 cm carapace length), but some may not mature unti l 30 cm PL. When compared to data from other parts of the species rang e, body size and size at maturity show no evidence of geographic varia tion. Follicles first reach ovulatory size in late February, and femal es first bear oviducal eggs in early March. Nesting season apparently lasts from late March to early August, during which each female may pr oduce as many as five or six dutches of 9-38 eggs (mean = 20.6). This annual fecundity is higher than any other North American freshwater tu rtle species. However, 9% of mature females (i.e., >30 cm PL) had inac tive ovaries (i.e., maximum follicle diameters (6 mm and no corpora lu tea) during the reproductive season, suggesting that some females may not reproduce every year. Clutch size increases with female body size, but egg size does not (mean, 28.2 mm x 27.5 mm, 12.3 g). The lack of egg size variability across body size, dutch size, season, and geograp hy suggests selection for optimal egg size. Clutch mass averages 4.1% (3.0-5.2%) of spent body mass and does not vary seasonally. Apalone fe rox reaches a larger size, has larger eggs, and produces as many as tw ice the number of clutches per year as its North American congeners; h owever, it is quite similar reproductively to several Old World triony chid species, including its closest outgroups.