Loggerhead sea turtle although loggerhead sea turtles cannot retract their heads or flippers into their shells. Sexual dimorphism of the loggerhead sea turtle is only apparent in adults. Adult males have longer tails and claws than females. The males' plastrons are shorter than the females', presumably to accommodate the males' larger tails. The carapaces of males are wider and less domed than the females', and males typically have wider heads than females. The sex of juveniles and subadults cannot be determined through external anatomy, but can be observed through dissection, laparoscopy (an operation performed on the abdomen), histological examination (cell anatomy), and radioimmunological
Loggerhead Key done to provide the monkeys a place to breed, to supply the animals for medical research laboratory experiments. Around 1,322 of the monkeys existed on the island between 1987–1990. The Dry Tortugas Light is a lighthouse located on Loggerhead Key. It began operations in 1858 and was decommissioned in 2014. The Carnegie Marine Biological Laboratory, also referred to as the Tortugas Laboratory, was a marine biology laboratory and research facility constructed on the northern end of Loggerhead Key that operated from 1904 to 1939. It was constructed and operated by the Carnegie Institution of Washington. The Carnegie Marine Biological Laboratory