Development of Buoyancy Control in Juvenile Atlantic Loggerhead Turtles, Caretta c. caretta

feeding, protection and/or habitation must of necessity be denser than water if it is to remain there passively for any period of time. Both aquatic and semiaquatic turtles are known to float quietly at the surface of the water and to remain passively submerged. Several studies have established the ability to accurately adjust specific gravity for buoyancy regulation for members of both groups of turtles (Jacobs, 1939; Jackson, 1969; Milsom, 1974). Although such control has been established for the adult Atlantic loggerhead turtle, Caretta caretta, (Jacobs, 1939; Milsom, 1974) it has long been known that newly hatched turtles of this species are too buoyant to sink and the ability to dive develops gradually (Hooker, 1908). This study examines specific gravity changes during juvenile development and the onset and development of buoyancy control in this turtle.