Description

Green turtles are the largest of the hard-shelled sea turtles, growing to 40 inches in carapacial length and up to 350 pounds in weight. The shells are typically smooth, tear shaped and have four costal scutes. Carapacial color varies from olive through shades brown to black. Overlying this ground color are radiating lines, either complete or broken, of buff or reddish brown. The head is relatively small. The venter is immaculate white or cream.

Distribution

Green turtles occur worldwide in tropical oceans and in the Mediterranean sea. In Panama, this species is found primarily in the Caribbean on offshore seagrass beds and occasionally enters embayments such Almirante Bay and Chiriqui Lagoon in Bocas del Toro.

Habitat & Ecology

Green turtles make a pronounced transition in diet and habitat during their life. Hatchlings are pelagic and feed primarily on crustaceans and other invertebrates. After about 10 years, when 1 ft. in carapace length, they transition to a benthic vegetarian diet on shallow sea grass beds. From this point onward they feed exclusively on seagrass (Thalassia).

Reproduction

Green turtles show the greatest degree of site fidelity of any of the marine turtles and always return to the beach on which they hatched. No adult female green turtle has ever been found nesting on more than a single beach, and they are even known to return to the same section of beach. Green turtles nest every five to seven years and may nest seven to nine times in any one nesting season. This species prefers wide beaches and typically place nests at the edge of beach-side vegetation. They require up to three hours to complete a nest. After 60 days, the hatchlings erupt together at the surface and scramble to the water. Here they enter a “frenzied swimming” stage that lasts 24-36 hrs which allows them to move away from land and into offshore currents. The nesting season extends from June through August with peak activity in July. The primary nesting location for green turtles in the western Caribbean is Tortuguero, Costa Rica, and very few nest in the Bocas del Toro region or other areas of Panama.

Conservation

Due to its delectable flesh and soup made from the green-colored fat located inside the carapace (calipe), green turtles have been utilized extensively as a protein source by both native peoples and by Europeans. In Bocas del Toro, Panama, green turtles are still often caught in nets set on offshore grass beds, taken on nesting beaches, or by speared when they come up for air. Poachers in the region will also attract green (and hawksbill) turtles using balsa-wood decoys either tied to the tops of nests or trailed behind a dugout canoe. Male turtles are attracted to these decoys and are speared when they surface to investigate. The eggs are also consumed and were large nesting aggregations occur, such as Tortuguero, egg poaching is a frequent problem. Like other sea turtle eggs, the eggs of green turtles are often sold in bars as aphrodisiacs. Several Panamanian organizations are involved with the conservation of nesting green turtles in Bocas del Toro, including ANAM, ITEC and Promar.

Other Comments

None.

References

• Auth, D.L. 1994 Checklist and Bibliography of the Amphibians and Reptiles of Panama, Smithsonian Herptological Information Service. 98.
• Frank, N., & E. Ramus 1996 A Complete Guide to Scientific and Common Names of Reptiles and Amphibians of the World. NG Publishing, 337 pp.

Other Available References from the EMBL REPTILE DATABASE .

• LINNAEUS, C. (1758) Systema Naturae. 10th Edition: 204 pp
• Bemmelen (1893) Ann. Mag. nat. Hist. (6) 12: 477-478
• Bocourt (1868) Ann. Sci. Nat. Zool., (Ser. 5) 10 (Pts. 1-3), p. 122
• Boulenger (1887) Ann. Mag. Nat. Hist. (5) 20: 407-408
• Boulenger (1889) Cat. Chelonians, Rhynchocephalians, Crocodiles.
• Cogger (2000) Rept. Amph. of Australia, 6th ed.
• Conant & Collins (1991) Field Guide Rept. Amph. E/C North America, 3rd ed.
• Cox etc. (1998) Phot. Guide Snakes Rept. Peninsular Malaysia, Singapore and Thailand.
• Duméril & Bibron. (1835) Erpétologie Générale, Rept., Vol. 2.
• Engelmann etc. (1993) Lurche Kriechtiere Europas.
• Ernst & Barbour (1989) Turtles of the World.
• Fritz (1995) Herpetofauna 17 (95): 19-34
• Glaw & Vences (1994) Fieldguide Amph and Rept. Madagascar.
• Gray (1873) Ann. Mag. Nat. Hist. (4) 12: 109-114
• Günther (1864) Rept. British India.
• Hirayama (1994) Island Arc 3:270-284
• Hirth (1980) Cat. Amer. Amph. Rept. No. 249 1980: 1-4
• Hirth (1980) Cat. Amer. Amph. Rept. No. 248 1980: 1-2
• Iverson (1992) revised Checklist ... Turtles of the World, Richmond, Indiana, 363 pp.
• Kasparek (1990) Salamandra 26 (2/3): 155-164
• Köhler (2000) Rept. Amph. Mittelamerikas, Bd 1.
• Limpus etc. (1988) Transactions of the Royal Society of Australia 112 (1):1-9
• Linnaeus (1758) Systema Naturae.
• Merrem (1820) Versuch eines Systems der Amphien I.
• Mertens etc. (1928) Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft. Frankfurt am Main. 41: 1-62.
• Penyapol (1958) Nat. Hist. Bull. Siam Soc. (Bangkok) 17: 23-36
• Stebbins (1985) Field Guide Western Rept. and Amph., 2nd ed.
• Stejneger (1907) Bull. US. Natl. Mus., Washington, 58: xx, 1-577
• Stuart (1963) Misc. Publ. Mus. Zool., Univ. Michigan (No. 122): 1-150
• Swash etc. (2001) Birds, Mammals, Reptiles Galapagos. Pica Press, 168 pp.
• Thunberg (1785) Museum naturalium Academiae Upsaliensis, 33 parts.
• Thunberg (1787) Kongl. Vetensk. Acad. Nya Handlingar, För M_naderne 1787: 178-180 .

Reference written by Dr. P. Lahanas, Institute for Tropical Ecology & Conservation Page last updated 14 May, 2003 Comments or Corrections: HerpsofPanamaITEC-edu.org Copyright © 1999-2003