The Female Reproductive Cycle of the Florida Softshell Turtle (Apalone ferox)
1997; The Society for the Study of Amphibians and Reptiles; Volume: 31; Issue: 3 Linguagem: Inglês
10.2307/1565669
ISSN1937-2418
AutoresJohn B. Iverson, Paul E. Moler,
Tópico(s)Animal Behavior and Reproduction
ResumoThis study of the female reproductive cycle of Apalone ferox in south Florida was based on 220 reproductive tracts salvaged from females butchered for meat. Some females mature at sizes as small as 24 cm plastron length (PL; ca. 31 cm carapace length), but some may not mature until 30 cm PL. When compared to data from other parts of the species range, body size and size at maturity show no evidence of geographic variation. Follicles first reach ovulatory size in late February, and females first bear oviducal eggs in early March. Nesting season apparently lasts from late March to early August, during which each female may produce as many as five or six clutches of 9-38 eggs (mean = 20.6). This annual fecundity is higher than any other North American freshwater turtle species. However, 9% of mature females (i.e, >30 cm PL) had inactive ovaries (i.e, maximum follicle diameters <6 mm and no corpora lutea) 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, clutch size, season, and geography 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 ferox reaches a larger size, has larger eggs, and produces as many as twice the number of clutches per year as its North American congeners; however, it is quite similar reproductively to several Old World trionychid species, including its closest outgroups.
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