Loggerhead turtles (Caretta caretta) are opportunistic carnivores that feed primarily on invertebrates and fish. In the wild, they eat a variety of foods depending on their life stage and geographic location.
However, for sea turtles in rehabilitation, part of the healing process is to provide them with a balanced diet so that injured, diseased, malnourished and disabled turtles gain weight and improve their body condition.
Stomach analysis
However, finding a nutritionally balanced formula is challenging. For this reason, a team of scientists led by the Harbor Branch Oceanographic Institute of Florida Atlantic University (United States) has carried out a study.
They hypothesized that analysis of stomach contents and clinical pathology data from wild loggerhead turtles would allow the development of nutritional indices that could be applied to better address the dietary needs of captive loggerhead turtles.
Study development
For the study, published in the Journal of Animal Physiology and Animal Nutrition, they examined the stomach contents of 153 deceased loggerhead turtles that had been stranded off the Georgia coast. Information on stomach content was used to determine the most common prey, which was subsequently evaluated for nutritional content.
The results were used to formulate a specific diet and develop a supplement containing vitamins and minerals for the loggerhead turtles in captivity. They designed a vitamin and mineral supplement as well as an intensive care diet based on this data.
“The data from our study can be used to allow keepers to become closer to a normal diet for captive loggerhead turtles, including providing vitamin and mineral supplements where appropriate,” explained Annie Page-Karjian author. principal of the study.
Conclusions
The proportion of certain prey elements differed significantly with the size of the turtle. The adult turtles ate a greater number of more gastropods, while the smaller turtles ate fish.
On the other hand, seasonal effects were evident in the relative abundance of certain prey, such as crabs in the colder months and mollusks in the warmer months.
The evaluation of regional and temporal variability in diets is an important component for their conservation, as the resulting data could be used to understand the impacts of environmental disturbances on food webs.
“The results of our study support the hypothesis that the composition of a loggerhead turtle’s diet changes and adapts over time to changing prey availability,” argued the lead researcher.
