Sagittal projection image of the skull of a wild loggerhead sea turtle. What are the mineralized round structures in the oral cavity?
The skull is normal. There are multiple external and lingual barnacles present (orange arrows). Barnacles are a common epibiont of sea turtles. There are various species of barnacles that attach to sea turtles. Barnacles often do not cause a problem for the sea turtles and can provide shelter other organisms. Depending on the location, barnacles can cause irritation to the tissues of the sea turtle causing opportunistic bacterial or fungal infections.
What is this animal? Is it adult or juvenile?
This is a juvenile loggerhead sea turtle! The first image is highlighting the lungs. The lungs of sea turtles run just under the carapace (top portion of the shell). This juvenile was one of approximately 100 eggs that hatched from the nest after two months of incubation in the sand on the beaches of Australia. This little one will hopefully grow to be approx. 100 kg at adult size. Loss of nesting habitat due to coastal development (e.g. houses), predation of nests, and human disturbances (e.g. street lighting and housing light pollution) threatens their survival. The sex (male v. female) of hatchlings is determined by the temperature of the sand nest while the egg incubates on the beach. Rising global temperatures has caused an increase in the number of female loggerheads born each year.