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Home › Sea Wildlife › Marine Animals › Vertebrates › Sea Turtles

Interesting Facts about Sea Turtles

[Sea Turtle Phylum: Chordata] [Class: Reptilia] [Order: Testudines] [Superfamily: Chelonioidea]

Despite needing to breathe air, all seven (7) sea turtle species are in fact marine reptiles that spend almost all of their lives in the world's oceans.

This section contains crucial facts and information about marine turtles, including where they still exist, what they eat, and how they reproduce.

Sea Turtle Habitat and Geographical Range

The 7 extant (surviving) species of sea turtle in the IUCN Red List are:

• Flatback sea turtle (Natator depressus) listed as "Data Deficient"
• Green sea turtle (Chelonia mydas) "Endangered" and "Decreasing"
• Hawksbill sea turtle (Eretmochelys imbricata) "Critically Endangered"
• Kemp's ridley sea turtle (Lepidochelys kempii) "Critically Endangered"
• Leatherback sea turtle (Dermochelys coriacea) "Vulnerable"
• Loggerhead sea turtle (Caretta caretta) "Vulnerable" and "Decreasing"
• Olive ridley sea turtle (Lepidochelys olivacea) "Vulnerable"

Excluding the polar regions, some populations of marine turtles still exist in all oceans. However, the only place to find the flatback sea turtle is the northern coast of Australia.

Similarly, you'll only find the Kemp's ridley sea turtle along the East Coast of the United States and in some parts of the Gulf of Mexico.

Here's the thing:

In general, the preferred setting for sea turtles habitat is warm or tropical waters close to shallow coral reefs and continental shelves.

Yet, most species of sea turtle will spend the first few years of their life floating in open water (pelagic zones) and near seaweed mats.

For example, green turtles tend to live near brown macroalgae Sargassum mats, mainly for plentiful food supplies and shelter.

But, upon reaching adulthood, these gigantic marine reptiles migrate and settle closer to coastal shorelines. As a consequence, the sandy spawning beaches are the places where females go to lay eggs when the nesting season arrives.

Fun Fact: The marine turtle species actually lived alongside dinosaurs over 100 million years ago. Still, a current estimate suggests only one (1) out of every one thousand (1,000) hatchlings will reach adulthood.

Sea Turtle Characteristics and Behaviour

Even though males and females in all seven sea turtle types are the same size, several key factors in sea turtle anatomy help to differentiate the genders in adults.

For instance, male sea turtles have a longer tail than the females. Furthermore, the single cloacal opening (used for releasing waste products) is closer to the tip in males and nearer to the base in females.

However, because sexual dimorphism does not exist in the hatchlings, there is no way to determine young males from females simply by looking at them.

Sea Turtles Description

When compared with their terrestrial counterparts, turtles that live in the ocean have more of a "fusiform" torpedo body shape that is tapered at the front and the back.

Having a large body helps them move great distances. It also offers some protection against their main predators, the shark species, groupers, and octopuses.

This spindle-like streamlined shape reduces volume, friction, and drag to aid swimming.

But, unlike land turtles and tortoises, sea turtles are unable to protect themselves by retracting the head and limbs into the shell.

But wait - there's more:

More than fifty (50) bony plates fuse together to form a sea turtle shell, the upper carapace and the lower plastron.

But, even though it's not a typical exoskeleton, having bones on the outside helps to protect the internal organs.

Fun Fact: The leatherback sea turtle phylum Chordate is an exception. Not only do leatherbacks survive in colder water, the sea turtle classification Dermochelys coriacea (lute turtle) has leathery skin. Another segment contains some interesting facts about freshwater turtles and how they differ from their saltwater counterparts.

Sea Turtle Size and Weight

The leathery turtle is the heaviest of all sea turtles and can weigh up to five hundred (500) kilograms (over 1,000 pounds). Fully grown adults can also measure almost three (3) metres in length (flipper to flipper).

By and large, the other sea turtle species are much smaller. For example, Kemp's ridley species is the smallest at sixty (60) centimetres (2 feet) long, and the sea turtle genus Chelonia grows to a length of about 120 centimetres (3.9 feet).

What Do Marine Turtles Eat?

Not having any teeth means marine turtles need to use their beak-like mouth to grab their favourite food, usually seaweed, algae, and jellyfishes (cnidarians).

Even though some species focus on certain types of prey, and the diet tends to change as some get older, most of the omnivorous feeders are also known to eat:

• Decapods (aquatic crustaceans)
• Echinoderms (e.g. sea urchins)
• Saltwater mollusks
• Sea sponges (Metazoans)
• Soft corals (Alcyonacea)

How Do Sea Turtles Reproduce?

When baby sea turtles reach maturity, from the age of ten, they reproduce through a process that starts off in the ocean but will end on a sandy beach.

Mating in the Ocean

By and large, turtles mate in a shallow coastal area sometime between spring and summer. Their mating process actually occurs in water, so the male will use its claws and tail to grasp the female.

However, because the females are able to store sperm from more than one male, they can use it to fertilise their eggs over several nesting events.

Nesting on a Natal Beach

The nesting takes place on the same beach where the female first started life and occurs every two to three years.

During the cover of darkness, she will crawl onto the sand and dig a large hole with her flippers. After laying up to two hundred (200) eggs, they will start to hatch after several weeks of incubation (up to 70 days) depending on the air temperature.

Hatching and Survival Rates

Despite emerging at night time, and guided only by the moonlight, the hatchlings scurry their way toward the ocean.

A variety of environmental threats, including their natural predators, means only a handful will survive and get a chance to expand the population.

Sea Turtle Threats and Predators

The focus of several worldwide conservationists that aim to help save the sea turtle from extinction see the green turtle, loggerheads, leatherbacks, and hawksbill turtles as the most pressing cases.

In truth, the demise of these ancient seawater creatures primarily results from human greed and ignorance. The survival of many marine reptiles are in serious danger because of the exploitative value of their eggs, skin, and their magnificent shells.

It gets worse!

As if this barbaric slaughter wasn't enough, they also die by accidental capture. Some poachers and fisherfolk are oblivious to the destruction and suffering that their activities and industries cause to sea turtle populations, such as entanglement in fishing gear.

The current facts about global warming and rising sea temperatures suggest that turtle nesting sites - and the sex of their offspring - are directly affected by the earth's climatic issues.

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