Green turtle, Loggerhead turtle, Sea turtles


Insight into blood values for free-ranging populations of chelonians is very incomplete. A better understanding of marine turtle ecological physiology is necessary for population health assessments and conservation management plans. Vitamins A and E are fat-soluble compounds required by vertebrates. Vitamin A is required for growth, differentiation and integrity of epithelial tissue, bone remodeling, reproduction and vision. Vitamin E is a constituent of cell membranes where it is an antioxidant and free radical scavenger. Both nutrients are required for reproduction and immune system function. I determined concentrations of vitamins A and E in plasma of blood samples from Caretta caretta and Chelonia mydas using high performance liquid chromatography (HPLC).

The first investigation focused on vitamin concentrations in nesting Caretta caretta and Chelonia mydas in the Archie Carr National Wildlife Refuge, Melbourne Beach, Florida, USA. Vitamin A concentrations were significantly higher in the herbivore, Chelonia than in the carnivore, Caretta. Plasma vitamin A concentrations decreased in Caretta as the nesting season progressed, while they remained constant in Chelonia. Plasma vitamin A concentrations only decline after liver stores of the vitamin are depleted, so it appears Caretta did not feed during the nesting season. Plasma vitamin concentrations in Chelonia remained stable during the nesting season, so it is not clear whether green turtles fed or fasted as the season progressed. Plasma vitamin E concentrations were significantly higher in Caretta than in Chelonia. This suggests that marine turtles follow the previously established chelonian pattern of carnivores having greater circulating concentrations of vitamin Ethan herbivores.

The second study focused on vitamin concentrations in subadult Caretta and juvenile Chelonia from three Atlantic coastal habitats: Indian River Lagoon (IRL), the Nearshore Reef and Trident Submarine Basin. The disease fibropapillomatosis (FP) is prevalent in turtles from the IRL and the Nearshore Reef but not Trident Submarine Basin. Vitamin E concentrations differed significantly among turtles with different degrees of FP affliction. Turtles moderately afflicted with had significantly lower plasma concentrations of vitamin E compared with turtles not afflicted with the disease and as a result, may have compromised immune status. In contrast, however, severely afflicted turtles did not have lower circulating levels of vitamin E compared with those of mildly afflicted turtles. Vitamin A varied significantly among Chelonia from the three different developmental habitats. Turtles from the IRL had significantly higher concentrations of circulating vitamin A than turtles from both the Reef and Trident Basin. Chelonia on the Reef had significantly higher circulating concentrations of vitamin E than turtles in Trident Basin. Chelonia in the IRL had vitamin E concentrations that did not differ significantly from either the Nearshore Reef or Trident Basin turtles. Plasma vitamin E concentrations increased with decreasing straight-line carapace length in Chelonia. This is one of the largest scale vitamin studies conducted on reptiles and will contribute to conservation of marine turtles by providing baseline data on vitamins A and E. This information is useful for wildlife rehabilitators and zoos and aquaria with captive marine turtles. Effects of reproduction and disease on plasma concentrations of vitamins A and E are also discussed in this thesis.

Graduation Date





Ehrhart, Llewllyn M.


Master of Science (M.S.)


College of Arts and Sciences






67 p.




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Masters Thesis (Open Access)




Arts and Sciences -- Dissertations, Academic; Dissertations, Academic -- Arts and Sciences

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