Chelonia mydas   (Linnaeus,  1758) (Turtle)
Organism information awaits expert curation
Class: Reptilia

Image copyrights: Marinebio

Size: Attains carapace length of over a meter.

Weight: Adult weighs over 150 kg

Carapace length: 90-120 cm

Carapace shape: Broadly oval; margin scalloped but not serrated.

Costal scutes: 4 pairs.

Head shape: Anteriorly rounded

Prefrontal scales: 1 pair

Limbs: Single claw on each flipper

Plastron: White in hatchlings, yellowish in adults

Color: The carapace of adult vary in color from black to grey to greenish. Also seen bold streaks or spots. The plastron is yellowish white in color.

This is the largest hard shelled sea turtle; the carapace of the females is richer in pigmentation. Diagnostic feature of this species is the 4 costal and 25 marginal shields of carapace. The shields do not overlap. The flippers have single claw each. The head bears a single pair of prefrontal shields. The jaws are not hooked. The sea turtles nests well above the sea line; the nesting activities being accomplished in late evening or night. The track imprint of a nesting individual of this species ranges between 91-112 cm wide. It makes a depression in the sand with the fore flippers and then deepens the nest hole with its hand flippers. The nest hole is oval and about 80 cm below the sand surface. Average clutch size is 104 eggs laid in 15 minutes. On completing egg laying, the nest hole is filled and done up, to camouflage the nest. After about 45 days of incubation, the hatchlings emerge.

Sea turtles spend almost all their lives submerged but must breathe air for the oxygen needed to meet the demands of vigorous activity. With a single explosive exhalation and rapid inhalation, sea turtles can quickly replace the air in their lungs. The lungs are adapted to permit a rapid exchange of oxygen and to prevent gasses from being trapped during deep dives. The blood of sea turtles can deliver oxygen efficiently to body tissues even at the pressures encountered during diving. During routine activity green and loggerhead turtles dive for about 4 to 5 minutes and surface to breathe for 1 to 3 seconds.

The incubation period doubles when the ambient temperature is less. The hatchlings erupt from the nest at night or even during the day if a shower lowers the sand temperature. The hatchlings rush towards the sea, during which decimation factors operate. The species nests throughout the year, but with the peaks from May to September. A female may nest every 2-3 years.

Although sea turtles move swiftly in the ocean, they are slow and defenseless on land. Male sea turtles almost never leave the water. Female sea turtles leave the ocean only to lay eggs and, for most species, nest only at night. A female loggerhead tracked at sea made up to 500 dives every 12 hours.
Although sea turtles cannot withdraw their heads into their shells, the adults are protected from predators by their shells, large size, and thick scaly skin on their heads and necks. Turtles can rest or sleep underwater for several hours at a time but submergence time is much shorter while diving for food or to escape predators. Breath-holding ability is affected by activity and stress, which is why turtles drown in shrimp trawls and other fishing gear within a relatively short time.

Synonym (s)
Caretta cepedii Merrem, 1820
Caretta thumbergii Merrem, 1820
Chelone mydas Boulenger, 1889
Chelonia depressa Garman, 1880
Chelonia lachrymata Cuvier, 1829
Chelonia midas Dumeril & Bibron, 1835
Chelonia mydas Smith, 1930
Euchelus macropus Girard, 1858
Mydas viridis Gray, 1870
Natator tessellatus McCulloch, 1908
Testudo japonica Thunberg, 1787
Testudo macropus Walbaum, 1782
Testudo marina vulgaris Lacepede, 1788
Testudo mydas Linnaeus, 1758

Common Name (s)
• Green Sea Turtle (English)
• Green Turtle (English)
• Paar Aamai
Economic Importance and Threats
Threats:  Anthropogenic
(Human predation is heavy as the fat, cartilage and meat of the green turtle is in demand for soup. Some tribal’s consume turtle eggs. The flippers of this turtle are used to make shoes as protective footwear against corals. )

Habitat:  Reef Associated, Coastal
Prey:  Seagrass, marine algae, jellyfish, comb jellies, crayfish, and crabs.
Predator:  Ghost crab (Ocypode species), Red hermit crab (Coenobita species) are predator on hatchlings and eggs.
IUCN Status:  Endangered


• Gujarat, Gulf of Kachchh (Lat: 22.6) (Long: 69.5) INDIA
• Gujarat INDIA
• Tamil Nadu, Gulf of Mannar (Lat: 8.5) (Long: 79) INDIA
• Lakshadweep (Lat: 11) (Long: 72.5) INDIA
• Andaman and Nicobar Islands (Lat: 12.53) (Long: 92.82) INDIA
• Gujarat, Mangrol Beach (Lat: 21.1) (Long: 69.61) INDIA (Record: 2000-2002)
• Gujarat, Porbandar Beach (Lat: 21.63) (Long: 70.1) INDIA (Record: 2000-2002)
• Tamil Nadu, Chennai INDIA
• Lakshadweep INDIA
• Andaman and Nicobar Islands INDIA
• Tamil Nadu, Gulf of Mannar INDIA
• Orissa, Bhitarkanika INDIA
• Palk Bay INDIA
• Kerala, Vizhinjam (Lat: 8.36) (Long: 76.98) INDIA (Record: 1994–2002)
• Lakshadweep Islands INDIA (Record: 1977-1979)
• Kerala, Vizhinjam (Lat: 8.37) (Long: 76.95) INDIA

Literature Source(s)
  • (2001) Sanctuary Asia natural history species: Species checklist: Reptiles Sanctuary Asia Sanctuary Magazine Available at -
  • Alfred, JRB; Das, AK and Sanyal, AK (Eds.) (1998) Faunal diversity in India ZSI, Calcutta 1-497 Available at - NCL, Pune
  • Sharma, RC (1998) Fauna of India Reptilia Testudines and Crocodilians ZSI, Kolkata 1 Available at - NCL, Pune
  • Tikader, BK and Sharma, RC (1997) Handbook: Indian Testudines ZSI, Kolkata 1-135 Available at - NCL, Pune
  • Venkatraman, K; Srinivasan, M; Satyanarayana, CH and Prabhakar D (2002) Faunal diversity of Gulf of Mannar biosphere reserve Conservation area series 15 ZSI 77 pp; VIII pla Available at - NCL, Pune
  • Tikader, BK and Das, AK (1985) Glimpses of animal life of Andaman and Nicobar Islands ZSI, Kolkata 1-170 Available at - NCL, Pune
  • (1994) The red data book on Indian animals Vertebrata part 1 ZSI, Kolkata 1-534 Available at - NCL, Pune
  • Tikader, BK (1983) Threatened animals of India ZSI 1-285 Available at - NCL, Pune
  • Molur, S and Walker, S (1998) Reptiles of India. Report summary 1998 Zoos' Print Journal Zoo Outreach Organisation, Coimbatore 13(7) 1 Available at - NCL, Pune
  • Spring, CS and D, Pike (1998) Tag recovery supports satellite tracking of a green turtle Marine Turtle Newsletter 82 Available at - Zoological Records
  • Vazirani, TG (1958) On a collection of Gyrinidae (Coleoptera) in the Zoological Survey of India, with the descriptions of two new species Records of the Indian Museum 53(1-2) 13-17
  • Borkar, M (2005) Marine mammals, turtles and crocodiles: A field manual NIO, Goa 63 pp Available at - NIO
  • MarineBio Available at -
  • (2003) IUCN Red list of threatened species Available at -
  • Venkatesan, S; Kannan, P; Rajagopalan, M and Vivekanandan, E (2004) Nesting ecology of the green sea turtle Chelonia mydas along the Saurashtra coast Journal of the Marine Biological Association of India The Marine Biological Association of India, Cochin 46(2) 169-177 Available at - NIO, Goa
  • Marine Biological Station, Chennai, Tamil Nadu (2003) Checklist of marine fauna of Tamil Nadu Department of Environment, Government of Tamil Nadu Available at -
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Untawale, AG; Dhargalkar, VK and Deshmukhe, GV (2000) Prioritization of potential sites for marine biodiversity conservation in India Setting biodiversity conservation priorities for India: Summary of the findings and conclusions of the biodiversity conservation prioritization project World Wide Fund for Nature - India, New Delhi (India) Available at -
  • Dr. Ramesh, R; Dr. Nammalwar, P and Dr. Gowri, VS (2008) Database on coastal information of Tamil Nadu Report Submitted to Environmental Information System (ENVIS) Centre, Department of Environment, Government of Tamil Nadu Institute for Ocean Management, Anna University, Chennai, Tamil Nadu. Available at -
  • Chadha, S and Sekar, KC (1999) Bhitarkanika:myth and reality Nataraj publishers, Dehra Dun Available at - NIO, Goa
  • Dr. Kumaraguru, AK (2000) Studies on socioeconomics of Coral Reef resource users in the Gulf of Mannar coast, South India Centre for Marine and Coastal studies School of Energy, Environment and Natural Resources Madurai Kamaraj University, Madurai, India Available at -
  • Murugan, A (2005) Sea turtles in and around Tuticorin coast, Tamil Nadu: facts and problems Proceedings of the National Seminar on Reef Ecosystem Remediation SDMRI Special Research Publication No.9 250-252 Available at -
  • Krishnapillai, S (2005) Distribution and status of sea turtles along Trivandrum coast, south Kerala Proceedings of the National Seminar on Reef Ecosystem Remediation SDMRI Special Research Publication No.9 253-255 Available at -
  • George, KC; Thomas, PA; Appukuttan, KK and Gopakumar, G (1986) Ancillary living marine resources of Lakshadweep Marine Fisheries Information Service CMFRI, Cochin 68 46-50 Available at -
  • Bhaskar, S and Whitaker, R (1983) Sea turtle resources in the Andamans Mariculture potential of Andaman and Nicobar Islands-An indicative survey Bulletin of Central Marine Fisheries Institute CMFRI, Cochin 34 94-97 Available at -
  • Pillai, PKM and Augustine, SK (2000) A code list of common marine living resources of the Indian seas CMFRI Special Publication No.12 CMFRI 1-115 Available at -
  • Kannan, P; Rajagopalan, M (2007) Size composition and morphometry of incidentally captured sea turtles at Vizhinjam, South-west coast of India Journal of the Bombay Natural History Society 104(3) 288-297 Available at - NIO, Goa
  • Shenoy S, Berlie T and Shanker K (2011) Sea Turtles of India A Comprehensive Field Guide to Research, Monitoring and Conservation Dakshin Foundation and MCB Trust 148pp Available at - NIO

Page last updated on:2012-11-05

Back to Search