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Sea turtles (introduction – distribution – breathing – salt glands – utilization) – Video

Video credit: Glenda Vélez Calabria (Colombia)  –   Review: Abdel Rahman El Gamal

This video was taken in mundo marino and te mostramos lo que pasa en el fondo, Colombia

Introduction: Sea turtles have been around for a very long time and are one of the earth’s most ancient creatures since the time of dinosaurs which goes back to many millions of years. In general, the estimate for the lifespan of sea turtles is 70-80 years.

There are seven species of sea turtles in two families. The family Cheloniidae includes six hard shell turtles: flatback sea turtle (Natator depressus), green sea turtle (Chelonia mydas), hawksbill sea turtle (Eretmochelys imbricate), Kemp’s ridley sea turtle (Lepidochelys kempii), loggerhead sea turtle (Caretta caretta) and olive ridley sea turtle (Lepidochelys olivacea). The seventh species of leathery skin turtle, leatherback sea turtle (Dermochelys coriacea) belongs to the family Dermochelyidae.

Distribution and habitats: Sea turtles are reptiles that are found primarily warm and temperate waters in the world’s oceans except the Arctic. Most sea turtles undergo long migrations between their feeding grounds and their nesting beaches. Before its sexual maturation, sea turtles spend most of their time in the pelagic zone. Once they turn sexually mature, they move closer to the shore to lay their eggs during the nesting season.

Adaptation- Breathing: Sea turtles are almost submerged, but they must be able to breathe air to meet their oxygen demand. Their lungs are adapted to allow a rapid and efficient exchange of oxygen even at the pressure during deep dives. For some sea turtles species, turtles dive for about 4 to 5 minutes and surface to breathe for 1 to 3 seconds.

Adaptation – Salt glands: Like other marine reptiles, sea turtles rely on a specialized gland to rid the body of excess salt ions, because reptilian kidneys cannot produce urine with a higher ion concentration than sea water.All species of sea turtles have a salt excretory gland at the corner of the eye, in the nostrils, or in the tongue, depending upon the species. Such glands are capable of producing tears with a higher salt concentration than sea water. Because the leatherback turtle feeds primarily on jellyfish and other gelatinous plankton whose salt concentration equals those of sea water, the salt glands of leatherback are capable to handle the higher salt intake of their prey and also, their tears are much saltier than those of other species of sea turtles. 

Utilization by humans: Even though the hunting of sea turtles is banned in many countries, marine turtles are still harvested in many parts of the world for food especially in many coastal communities around the world who depend on sea turtles as a source of protein. Also, sea turtle eggs have been collected for consumption.

Some sea turtle species are targeted for their shells for decorative purposes rather than their meat. Expensive shoes and leather goods have been made of the skin of turtle flippers. The Moche tribe of ancient Peru worshiped turtles along with other sea animals. They often enormously depicted sea turtles in Moche art.

 

 

 

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Permanent link to this article: http://fishconsult.org/?p=10174

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