DIVE LOG Australasia

This juvenile Chelonia mydas from Lady Elliot Island is resting on a Soft Coral.

Turtles struck by propellors of boats may suffer a broken back, damaged vertebrae and spinal cord, broken ribs and a pierced lung. These are catastrophic injuries! They do have a Rib Cage but it is inside the lungs. The ribs are also fused to the inside of the shell so they are rigid. Therefore, muscles between the ribs, the intercostal muscles are no longer needed. Since the lungs are inside the shell, they cannot breathe in using a diaphragm muscle.They do not expand the lungs like we do. Rather, they use abdominal muscles to push against the stomach to exhale and an opposing pair of muscles to enable inspiration. They have a shoulder girdle and a hip girdle. Both of these are actually inside the rib cage. The upper shell or

carapace and the lower shell the plastron are kept apart by a pectoral girdle at the front and the pelvic girdle at the rear, otherwise their insides would get squeezed. Flippers have a classical Pentadactyl Limb with five fingers. These are fused inside the flippers. Bone X-Ray diagrams even reveal a thumb Florida state university has identified one hundred living creatures including parasites living on the skin and scores of types of algae. Bacteria or fungi can cause shells to rot which can be fatal. ADAPTATIONS FOR AQUATIC LIFE Turtles are very well adapted to life in the sea. They swim using mainly the sensitive front flippers. The rear limbs help somewhat and also steer. Females use them to dig nest holes.

Green turtle from Sipidan, East Malaysia. Note the single pair of very large scales between the eyes and the nostrils.

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DIVE LOG Australasia #408 - October ‘24