The green turtle (Chelonia mydas) is the second most common turtle seen in Keys’ waters.  Green turtles are herbivores, eating primarily turtle grass and other grasses and algae.  This vegetarian diet colors their body fat green and is where they get their name.  To help them easily graze on grasses, their jaws are serrated.  These turtles are fast swimmers and are more streamlined than loggerheads, with longer front flippers.  They are slower to mature than most sea turtles.

Common name: Green sea turtle (for the color of its body fat).  Is also known as the black sea turtle in some parts of the Pacific.

Scientific name: Chelonia mydas Family: Cheloniidae Group: reptiles

Status: Is listed as an Endangered species in the U.S. under the Federal Endangered Species Act

Range: temperate and tropical waters throughout the world

Size: The largest of the Cheloniidae family, adults are 3.5 to 4 feet in carapace length

Weight: to 400 pounds


Characteristics: carapace color is generally dark green to brown with radiating stripes.  Plastron is off-white to pale yellow.  Head is slim and blunt.  Jaws are serrated to aid in cutting grass blades.  Bony carapace has non-overlapping scutes (4 lateral scutes).  One claw per flipper.  Single pair of pre-frontal scutes (between eyes) is a defining characteristic.

In parts of the Pacific where this turtle is known as the black turtle, individuals are darker in coloration (including the plastron) and the body is more domed or vaulted in appearance.

Habitat: shallow coastal waters which support the growth of turtle grass (Thalassia testudinum).

Diet: as adults they are strictly herbivorous, and the only turtle to be so.  However, as juveniles (smaller than 8-10 inches in length) they are omnivores, eating a variety of crustaceans and invertebrates in addition to grass and algae.

Nesting: nest at intervals of 2-3 years, sometimes more.  Will lay 3-5 nests per year.  Average 100-120 eggs per nest.

Interesting facts: named for the color of its body fat which is used to make “green turtle soup” and gives the soup its color.  It is illegal to make or import turtle soup in the U.S. but it is still considered a delicacy in some parts of the world.  At one time, Key West was a major processing center for green turtles and turtle harvest was a profitable living.  Key West had a turtle cannery and turtles were housed in turtle kraals (a Caribbean word for corrals) until ready for butchering.  In Key West today you can see the old cannery building and can eat at the Turtle Kraals Restaurant, both on the site of the old industry.  No turtle on the menu however!