Sea Turtle Species

Loggerheads are large, hard-shelled sea turtles. They have huge heads and powerful jaws for feeding on shelled prey such as whelks and conchs. This sea turtle species is called a “loggerhead” because when resting at sea with just their heads out of the water, sailors often mistake them for floating logs.

They have a slightly heart-shaped carapace, which is often covered with commensal organisms such as barnacles and algae. It is estimated that up to 100 species may live on the carapaces of loggerhead turtles. This makes each turtle its own mobile ecosystem.

The loggerhead sea turtle is found in more places around the world than any other species of sea turtle. They are found throughout both temperate and tropical waters. They are found along the continental shelves and river estuaries of the Atlantic, Pacific and Indian Oceans. They are also found in the Mediterranean Sea. The largest nesting area is along the southeast coast of the United States, from North Carolina to Florida.

Adult loggerheads are known to make long migrations between feeding areas and nesting beaches. When not nesting, adult females born on U.S. beaches are distributed in waters off the eastern U.S. and throughout the Gulf of Mexico, Bahamas, Greater Antilles and Yucatán.

Loggerhead turtles are omnivores, eating both plants and animals. They mostly eat animals. They use their massive and powerful jaws to break open the hard shells of such prey as whelks and conchs. They also eat many other invertebrates such as jellyfish, shrimp, sea urchins, octopus and squid.

Loggerheads spend most of their lives in the open ocean or in shallow coastal waters. They almost never come ashore. Adult females only come ashore to nest. Males usually don’t come ashore at all. Adults tend to return to the same nesting grounds year after year and many females return to the very beach where they themselves hatched.

The green sea turtle is the largest of the hard-shelled sea turtles. The carapace is smooth and heart-shaped. The color of the carapace varies and has shades of black, gray, green, brown, and yellow. The plastron is yellowish white. The head appears small when compared to the body.

Greens have a single claw on each flipper. They have a distinctive pattern of scales and scutes as well. Their body fat is green.

Hatchlings have a black carapace, white plastron and white edging on the shell and limbs.

Green sea turtles are found in tropical and subtropical waters throughout the world. They live in the coastal areas of more than 140 countries and nest on the beaches of over 80 countries.

In the United States, green sea turtles are found in near-shore waters along the gulf coast and Atlantic coasts as far north as Massachusetts. They are also found in the U.S. Virgin Islands and Puerto Rico. There are many important feeding areas in Florida. Along the Pacific coast, green sea turtles have been sighted from Baja California to southern Alaska. In the central Pacific, green turtles occur around most tropical islands, including the Hawaiian Islands.

Green sea turtles will migrate long distances between feeding grounds and nesting beaches.

Green sea turtles, like all sea turtles, spend most of their lives in the water. In general, once sea turtles enter the water, they never come back on land except to nest. However, the green sea turtle occasionally comes ashore to bask.

The leatherback sea turtle is the largest sea turtle. The largest turtle on record measured almost 7 feet (2.1 m) in length. The leatherback does not have a solid, external bony shell like all of the other sea turtles. Rather, it has a loose bony structure covered by dark brown or black rubbery skin. This shell is about an inch and a half thick. The carapace has seven pronounced ridges that run from front to back. The lighter colored plastron has five ridges. Neither the front or back flippers have claws or scales. The flippers are longer relative to their body than those of other sea turtles. Hatchlings are heart-shaped and have white striping along the ridges of their backs and on the margins of the flippers.

This species has unique adaptations – even for sea turtles. Several adaptations make it possible for them to live in colder water than other sea turtle species. They have a network of blood vessels that work as a heat exchanger and a thick insulating layer of oils and fats in their skin. This, and their large size, makes it possible to maintain body temperatures that are much higher than the surrounding environment (Spotila, 2004). Other adaptations help leatherback turtles eat soft, gelatinous food like jellyfish. Pointed cusps and sharp-edged jaws act like teeth while backwards pointed papillae cover the throat, keeping the food headed towards the stomach and protecting the turtle from jellyfish stings.

The leatherback is the most wide-ranging of the sea turtles. They have a nearly worldwide distribution and travel long distances from their nesting beaches to their feeding grounds. They are mainly found in warm tropical waters. However, larger adults (those more than three feet in length) can also be found in colder water. These bigger turtles can be found far north as the cold subartic waters of Newfoundland, Nova Scotia and Labrador. They can also be found in the cold waters of southern Argentina and South Africa. Smaller animals are almost always found in warmer tropical waters.

Leatherback turtle nesting grounds are also located around the world, mostly on tropical beaches. The largest remaining nesting areas are found on the coasts of northern South America and West Africa. Within the U.S., there are small nesting colonies in the Caribbean and in southeast Florida.

Leatherbacks are primarily carnivorous. They eat soft-bodied prey found in the open ocean such as jellyfish and other invertebrates without shells. They will occasionally eat algae and seaweed.

Leatherbacks spend most of their lives in the open ocean. Little is known about the life history of hatchling to juvenile leatherbacks. Adult females only come ashore to nest. Males usually don’t come ashore at all. The life span of the leatherback is unknown but believed to be approximately 50 years in the wild.

The hawksbill is small to medium-sized sea turtle species. The carapace is dark to golden brown, with streaks of orange, red and/or black. The plastron is yellow. The hatchlings are mostly brown.

Hawksbill turtles have several features that distinguish them from other species of sea turtle. They have two pairs of prefrontal scales on the top of the head. Each of the flippers has two claws. Some of the scutes on the carapace overlap each other. The side and back edges of the carapace are serrated. Most notably, the elongated mouth resembles a bird’s beak.

Young hawksbills have a heart-shaped carapace. As they age the carapace becomes elongated.

Hawksbills can be found throughout the tropical waters of the Pacific, Atlantic and Indian oceans. They regularly occur in southern Florida and the Gulf of Mexico (especially Texas), in the Antilles and along Central America as far south as Brazil.

Like several other sea turtle species, the hawksbill is capable of migrating long distances between nesting beaches and foraging areas. For example, one female hawksbill traveled 1,160 miles from US Virgin islands to Nicaragua.

The most important nesting areas in the U.S. are in Puerto Rico and the U.S. Virgin Islands. Within the continental U.S., nesting occurs along the southeast coast of Florida and the Florida Keys. A few hawksbills have been reported nesting along the coasts of North Carolina and South Carolina.

Omnivore

As adults, hawksbills eat mostly sponges but will sometimes eat invertebrates and algae as well.

Once males leave their nesting beach they spend the rest of their lives in the water. Females only come ashore to nest. The lifespan of these animals is unknown but thought to be around 30 years.

Adult Kemp’s ridleys are the smallest of the sea turtles, with the carapace rarely exceeding 29 inches in length. The carapace of an adult Kemp’s Ridley is broad and light gray-olive in color and the plastron is creamy white. The carapace is usually as wide as it is long and has a distinctive pattern of scutes. The head is large with ridged, powerful jaws. Each of the front flippers has one claw, while the back flippers may have one or two. Hatchlings are grey-black all over.

Kemp’s ridleys can be found throughout the Gulf of Mexico and the U.S. eastern coast from New England to Florida. Almost all the Kemp’s ridleys in the world nest on one beach at Rancho Nuevo, Tamaulipas, Mexico. Nesting has also been reported throughout the Gulf of Mexico, as well as along the eastern coasts of Florida, Georgia, South Carolina and North Carolina.

Carnivore

Their diet consists mainly of swimming crabs, but may also include fish, jellyfish and an array of mollusks.

Once turtles have entered the sea, they seldom return to land. Males never come ashore. Females only come on shore to nest. With many reptiles, size is a more reliable indicator of sexual maturity than age. This is the case with sea turtles. Kemp’s ridleys take from 11 to 35 years to reach maturity. Females usually start nesting when they are between 10 and 17 years of age.

The adult olive ridley is relatively small. It can weigh up to 100 lbs and be as long as 30 inches. Its carapace is olive colored and heart shaped. This species varies somewhat in color, size and shape from region to region. The largest animals occur on the Pacific coast of Mexico. Each flipper has one or two claws.

Olive ridleys can be found in the tropical regions of the south Atlantic, Pacific and Indian Oceans. In the south Atlantic they can be found along the coasts of west Africa and South America. In the eastern Pacific they occur from southern California to northern Chile. Adult olive ridleys often migrate long distances between feeding and breeding grounds. Although nesting occurs in 40 different countries, arribadas occur only on a few beaches in the eastern Pacific and northern Indian oceans.

Omnivore

The Olive ridley eats a wide variety of food items. They eat algae, lobster, crabs, mollusks, shrimp, soft fleshy marine invertebrates and fish. They often dive to depths of 500 feet to forage on invertebrates.

With many reptiles, size is a more reliable indicator of sexual maturity than age. This is the case with sea turtles. Olive ridleys reach sexual maturity at about 15 years of age. When ready to breed, both males and females travel from feeding grounds to breeding areas just off shore of nesting beaching. Females return to the beach on which they were born to nest.

The flatback is a medium-sized hard-shelled sea turtle. The body is flat. The carapace has a thin, oval shape, with large non-overlapping scutes. The carapace is olive gray with brown/yellow margins. The carapace is turned up at the edges. The plastron is pale yellow. The head and front flippers are gray. Each flipper has one claw.

Flatback sea turtles are unique because they live their entire lives on the continental shelf north of the Australian continent. They never spend time in the open ocean. Beaches on small offshore islands are their most important nesting sites.

Carnivore

The flatback turtle is mainly carnivorous, feeding on squid, sea cucumbers, soft corals and mollusks. Occasionally they will eat seaweed.