Literaturdatenbank
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Aresco, M. J., Ewert, M. A., Gunzburger, M. S., Heinrich, G. L., & Meylan, P. A. (2006). Chelydra serpentina – snapping turtle. In P. A. Meylan (Ed.), Biology and Conservation of Florida Turtles Vol. 3, (pp. 44–57).
Added by: Sarina Wunderlich (30 Jun 2012 22:00:28 UTC) |
| Resource type: Book Article BibTeX citation key: Aresco2006 View all bibliographic details  |
Categories: General Keywords: Chelydra, Chelydra serpentina, Chelydridae, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Systematik = taxonomy Creators: Aresco, Ewert, Gunzburger, Heinrich, Meylan Collection: Biology and Conservation of Florida Turtles |
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The snapping turtle, Chelydra serpentina, is a large and familiar freshwater species that is easily recognized by its large head, long tail, large claws, serrated rear carapace, and reduced plastron. It is a widely distributed species that represents an ancient lineage of turtles. We follow the current taxonomy in recognizing two subspecies in Florida: C. s. serpentina and C. s. osceola. We found intergrades of C. s. serpentina and C. s. osceola in northwestern Florida that showed considerable overlap in shape of neck tubercles and ratio of the width of the third vertebral scute to the height of the second pleural scute. We did not find evidence of intergradation in northeastern Florida, thus the intergrade zone between C. s. osceola and C. s. serpentina appears to extend from coastal southeast Georgia and the Okeefenokee Swamp to the Apalachicola River and northward into southwest Georgia. Although not abundant in Florida, C. serpentina is found throughout the state with the exception of the Florida Keys. In Florida, C. serpentina is most abundant in small creeks, spring fed streams, small ponds (< 5 ha), floodplain swamps, borrow pits, drainage ditches, and other small fresh waters with soft bottoms and aquatic vegetation. They are also regularly found in cypress dome ponds and strand swamps in wet pine flatwoods of the Florida panhandle. Overland movements of C. serpentina are common in Florida and are associated with dispersal, nesting, and migrations from wetlands during drying or refilling. There are few data on growth of C. serpentina in Florida, but growth rates may be higher than in northern populations because of a longer growing season. In a population from Leon County in northwestern Florida, early growth (1–6 yrs) was variable among individuals and ranged from 10–30 mm/year; females matured at about 22 cm CL (6–8 yrs) and males at 18–19 cm CL (4–6 yrs). In central and south Florida, the nesting season begins as early as February–March and continues until late June, whereas nesting occurs from mid-April through June in northern Florida. Aquatic plants and macroinvertebrates are major components of the diet of C. serpentina in Florida. This species is not currently considered rare or endangered in Florida, however, it suffers from several threats and populations should be monitored. Habitat loss and fragmentation are significant threats as Federal and State regulations are insufficient to protect many of the wetland habitats (e.g., small, isolated, and seasonal wetlands) that support C. serpentina populations in Florida. Mechanical removal of organic sediment (“muck”) from lakes and ponds is an established wetland management technique in Florida and is a type of habitat alteration that is a serious threat to C. serpentina populations. There are currently no regulations in Florida that protect C. serpentina from excessive harvest and we lack adequate baseline data on the level of harvest of this species to properly assess population viability and set sustainable limits on use.
Added by: Sarina Wunderlich |