Sea Turtles

Sea Turtle Characteristics, Reproduction and Conservation

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Kennedy, Jennifer. "Sea Turtles." ThoughtCo, Dec. 31, 2015, thoughtco.com/sea-turtles-profile-2291900. Kennedy, Jennifer. (2015, December 31). Sea Turtles. Retrieved from https://www.thoughtco.com/sea-turtles-profile-2291900 Kennedy, Jennifer. "Sea Turtles." ThoughtCo. https://www.thoughtco.com/sea-turtles-profile-2291900 (accessed October 18, 2017).
Green sea turtle, Caribbean
Green sea turtle, Caribbean. Armando F. Jenik/Photographer's Choice/Getty Images

Seeing a sea turtle in the wild is an amazing experience. With their graceful movements, sea turtles seem to project a wise, calm aura. Here you can learn about characteristics common to all sea turtles. 

Sea Turtle Fast Facts:

  • Sea turtles are reptiles that live in a marine or brackish environment.
  • There are 7, possibly eight, species of sea turtles.  Some scientists classify the green turtle into 2 species - the green turtle and the Pacific green turtle or the black sea turtle.
  • Sea turtles are well-adapted for swimming in the water, but move poorly on land.

Sea Turtle Characteristics

The flippers of sea turtles are long and paddle-like, making them excellent for swimming but poor for walking on land. Another characteristic that helps sea turtles swim easily is their streamlined carapace, or shell. In most species, this shell is covered in large, hard scales called scutes. The number and arrangement of these scutes can be used to distinguish different sea turtle species.

The bottom part of a sea turtle's shell is called a plastron.

While sea turtles have fairly mobile necks, they cannot withdraw their heads into their shells. 

Classification:

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Reptilia
  • Subclass: Anapsida
  • Order: Testudines
  • Family: Cheloniidae or Dermochelyidae

Species of Sea Turtles

There are seven recognized species of sea turtles, six of which are in the Family Cheloniidae (the hawksbill, green, flatback, loggerhead, Kemp's ridley and olive ridley turtles), with only one (the leatherback) in the family Dermochelyidae.

In some classification schemes, the green turtle is divided into two species - the green turtle and a darker version called the black sea turtle or Pacific green turtle. 

Reproduction:

Sea turtles start their lives inside eggs buried in the sand. After a two-month incubation period, the young turtles hatch and run to the sea, facing attack by a variety of predators (e.g., birds, crabs, fish) along the way.

They drift at sea until they are about a foot long and then, depending on the species, may move closer to shore to feed.

Sea turtles mature at around age 30. The males then spend their whole lives at sea, while females mate with the males at sea and then go to the beach to dig a hole and lay their eggs. Female sea turtles may lay eggs several times during a single season.

Migration:

Sea turtle migrations are extreme. Turtles sometimes travel thousands of miles between cooler feeding grounds and warm nesting grounds. A leatherback turtle was reported in January 2008 to have undertaken the longest known vertebrate migration - over 12,000 miles. As an aside, this was later surpassed by the Arctic tern, who was found to make a record 50,000-mile migration! The turtle was tracked by satellite for 674 days from its nesting area in Jamursba-Medi beach in Papua, Indonesia to feeding grounds off Oregon.

As more sea turtles are tracked using satellite tags we learn more about their migrations and the implications their travels have for their protection. This may help resource managers develop laws that help protect turtles in their full range.

Sea Turtle Conservation:

All seven species of sea turtles are listed under the Endangered Species Act.

Threats to sea turtles today include the harvesting of their eggs for human consumption, entanglement and entrapment in fishing gear, ingestion of litter and coastal development.

References and Further Information: