Green Sea Turtles get their name from the color of their body fat,
which is green from the algae or grasses
they eat. The Hawaiian Green Sea Turtle population, is known by
its Hawaiian name Honu.
Green Sea Turtles are reptiles whose ancestors evolved on land
and returned to the sea to live. The first turtles appeared during
the Triassic period, 245 to 208 million years ago. Fossils for the
earliest known sea turtles appear in the Late Jurassic period, 208
to 144 million years ago. Turtles are one of the few species that
watched the dinosaurs evolve and become extinct.
As reptiles, sea turtles possess
the following traits:
- They are cold-blooded, meaning they get their body heat from
- They breathe air.
- Their skin is scale
Now, scientists recognize seven species of these marine reptiles.
The recognized sea turtle species are as follows: Greens, Hawksbill,
Kemp's Ridley, Olive Ridley, Loggerhead, Flatback and Leatherback.
The Loggerhead Sea Turtle is listed as threatened, the Flatback
is listed as vulnerable, and all other species are listed as endangered.
Green Sea Turtle populations of Hawaii are threatened and protected
in Hawaii under state law. Populations of Green Sea Turtles off
the coast of Florida and the Pacific coast of Mexico are listed
as endangered. Green Sea Turtles are protected by the federal Endangered
Species Act, and listed under the Convention on International Trade
of Endangered Species (CITES). CITES makes it illegal to import
or export turtle products.
In addition to their reptilian traits, all species of turtles except
the Leatherback have evolved a bony outer shell,
which protects them from predators. The Leatherback is the only
soft-shelled sea turtle and is in a family by itself. The shell
covers the dorsal (back) and ventral (belly) surfaces of a sea turtle. The dorsal portion of the shell
is the carapace and is covered with scale-like
structures called scutes, while the ventral
portion of the shell is known as the plastron.
Experts can identify species of sea turtles by the number and pattern
of scutes on the carapace. The shell is considered the most highly
developed protective armor of any vertebrate species. While most
land turtles can retract their heads into their shells for added
protection, sea turtles cannot and their heads remain out at all
Green Sea Turtles have green flesh. The carapace is olive brown
to black, while the plastron is pale yellow to creamy white. The
carapace is molted, variegated in color.
Rarely will you find a Green Sea Turtle with a solid colored shell.
Counter-shading of the shell conceals the turtle from predators,
making it difficult to distinguish the dark carapace from the sea
floor and the light plastron from the lighter sky.
Green Sea Turtles as hatchlings weigh about an ounce and have a
carapace length of 2 inches. A sexually mature green sea turtle
weighs 200-350 pounds with a carapace length of 2.5 feet. Adults
grow to a carapace length of 3.5 feet and weigh an average of 400
pounds. One of the largest turtles that ever lived from the Late
Cretaceaus period, 144 to 65 million years ago, reached a length
of 9.8-13 feet.
The lifespan of sea turtles is not known. It is believed that Green
Sea Turtles reach sexual maturity around the age of 25 years and
can live up to 80 years of age. The long period of maturation helps
to explain why it takes turtles so many years to recover from a
Sea turtles are wonderfully adapted to life in the ocean. Their
shells are lighter and more streamlined than land turtles. Front
and rear limbs have evolved into flippers. These flippers make sea
turtles efficient and graceful swimmers, capable of swimming long
distances in a short time.