Turtles inhabit saline, brackish or fresh water. Marine turtles are on this earth for more than 100 million years.

Marine turtles possess hard beak-like mouth to tear and mash food, a large carapace (upper shell), 2 pairs of strong flippers to swim inside the deep sea/ocean and lungs to breath air.

Due to a number of human activities like hunting for their meat and eggs, pollution, demolition of natural habitats like mangrove forests, coral reefs, nesting beaches etc. a number of marine turtle species are now considered as threatened.

There are seven marine-turtle species known so far among which six are found in Australia.

The following are the different species of marine turtles.

Caretta caretta (Loggerhead turtle)

• 55-95 cm long and weigh around 55 kg.
• Vertebral/coastal scutes in pairs
• 3 pairs of infra-marginal scutes
• Large head with strong jaws
• Front-flippers with two claws
• Males have thicker, longer tails and narrower shells
• Carnivorous

Chelonia mydas Green sea-turtle (name derived from their green colored fat)

• Length- 80-120 cm and weight- 130-250 kg
• Adults- brown, hatchlings- almost black
• Coastal scutes-2pairs
• 2 scales on the fore-head
• Single claw on each fore-flipper
• Omnivorous
• Strong jagged jaws

Dermochelys coriacea (Leatherback turtle)

• Largest sea turtles
• Dark blue to black, with pink or white patches
• 120-210cm long
• May weigh up to 900kg
• Skin smooth and leathery with numerous tiny bones embedded in it
• 7 elevated ridges on the shell-surface
• Claws absent
• Serrated jaws
• Carnivorous
• Can withstand a wider range of temperature

Eretmochelys imbricata (Hawksbill turtle)

• Greenish-brown to dark
• 55-95 cm long and 55kg weight
• Narrow jaws with overhanging and curved upper beak
• Scutes overlapping
• 2 claws on each of the fore-flippers
• Concave plastron in males, tail longer and thicker, bigger claws
• Carnivorous

Lepidochelys olivacea (Olive Ridley turtle)

• Grayish-brown Hatchlings and olive green adults
• Smallest sea-turtles (50-70cm long and around 50 kg in weight)
• Shell almost round with 6 to 9 lateral scutes
• Carnivorous
• Claws (1-2) grow on flippers

Natator depressus (Flatback turtle)

• Olive grey colored turtles
• Grow up to 97 cm in length and 84 kgs weight
• Flat and round shells
• Omnivorous
• Shell margins folded and covered by thin, non-overlapping waxy scutes

Lepidochelys kempii (Kemp’s Ridley)

• Gray to light olive green
• Size: 70 cm in length and weight 45 kg
• Five lateral scutes
• Claws present on the claws
• Carnivorous

Chelonia agassizi (Black turtle)

• Grayish black with black markings
• Length- 117cm and weight up to 126 kg
• Jaws- jagged
• Single claw on each front-flipper
• Omnivores