Loggerhead Sea Turtle

Caretta caretta

Summary 4

The loggerhead sea turtle (Caretta caretta), or loggerhead, is an oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around 90 cm (35 in) long when fully grown, although larger specimens of up to 280 cm (110 in) have been discovered. The adult loggerhead sea turtle weighs approximately 135 kg (298 lb), with the largest specimens weighing in at more than 450 kg (1,000 lb). The skin ranges from yellow to brown in...

Description 4

The loggerhead sea turtle is the world's largest hard-shelled turtle, slightly larger at average and maximum mature weights than the green sea turtle and the Galapagos tortoise. It is also the world's second largest extant turtle after the leatherback sea turtle.[1][2][3] Adults have an average weight range of 80 to 200 kg (180 to 440 lb) and a length range of 70 to 95 cm (28 to 37 in). The maximum reported weight is 545 kg (1,202 lb) and the maximum carapace length is 213 cm (84 in).[1] The head and carapace (upper shell) range from a yellow-orange to a reddish brown, while the plastron (underside) is typically pale yellow.[4] The turtle's neck and sides are brown on the tops and yellow on the sides and bottom.[5]

The turtle's shell is divided into two sections: carapace and plastron. The carapace is further divided into large plates, or scutes.[4] Typically, 11 or 12 pairs of marginal scutes rim the carapace.[6] Five vertebral scutes run down the carapace's midline, while five pairs of costal scutes border them. The nuchal scute is located at the base of the head. The carapace connects to the plastron by three pairs of inframarginal scutes forming the bridge of the shell.[7] The plastron features paired gular, humeral, pectoral, abdominal, femoral, and anal scutes.[6] The shell serves as external armor, although loggerhead sea turtles cannot retract their heads or flippers into their shells.[8]

Sexual dimorphism of the loggerhead sea turtle is only apparent in adults. Adult males have longer tails and claws than females. The males' plastrons are shorter than the females', presumably to accommodate the males' larger tails. The carapaces of males are wider and less domed than the females', and males typically have wider heads than females. The sex of juveniles and subadults cannot be determined through external anatomy, but can be observed through dissection, laparoscopy (an operation performed on the abdomen), histological examination (cell anatomy), and radioimmunological assays (immune study dealing with radiolabeling).[9]

Lachrymal glands located behind each eye allow the loggerhead to maintain osmotic balance by eliminating the excess salt obtained from ingesting ocean water. On land, the excretion of excess salt gives the false impression that the turtle is crying.[10]

Conservation 4

Since the loggerhead occupies such a broad range, successful conservation requires efforts from multiple countries.

Loggerhead sea turtles are classified as endangered by the International Union for the Conservation of Nature and are listed under Appendix I of the Convention on International Trade in Endangered Species, making international trade illegal. In the United States, the Fish and Wildlife Service and National Marine Fisheries Service classify them as a threatened species under the Endangered Species Act.[5] Loggerheads are listed as endangered under both Australia's Environment Protection and Biodiversity Conservation Act 1999 and Queensland's Nature Conservation Act 1992. The Convention on Migratory Species works for the conservation of loggerhead sea turtles on the Atlantic coast of Africa, as well as in the Indian Ocean and southeast Asia.[11][12] Throughout Japan, the Sea Turtle Association of Japan aids in the conservation of loggerhead sea turtles.[13] Greece's ARCHELON works for their conservation.[14] The Marine Research Foundation works for loggerhead conservation in Oman.[15] Annex 2 of the Specially Protected Areas and Wildlife Protocol of the Cartagena Convention, which deals with pollution that could harm marine ecosystems, also protects them.[5][16] Conservation organizations worldwide have worked with the shrimp trawling industry to develop turtle exclusion devices (TEDs) to exclude even the largest turtles. TEDs are mandatory for all shrimp trawlers.[5]

In many places during the nesting season, workers and volunteers search the coastline for nests,[17] and researchers may also go out during the evening to look for nesting females for tagging studies and gather barnacles and tissues samples. Volunteers may, if necessary, relocate the nests for protection from threats, such as high spring tides and predators, and monitor the nests daily for disturbances. After the eggs hatch, volunteers uncover and tally hatched eggs, undeveloped eggs, and dead hatchlings. Any remaining live hatchlings are released or taken to research facilities. Typically, those that lack the vitality to hatch and climb to the surface die.[18] Hatchlings use the journey from nest to ocean to build strength for the coming swim. Helping them to reach the ocean bypasses this strength-building exercise and lowers their chances of survival.[19]

Sources and Credits 5

1. Ernst 2009, p. 37
2. Dodd Jr, C. K. (1988). Synopsis of the biological data on the loggerhead sea turtle Caretta caretta (Linnaeus 1758) (No. FWS-88 (14)). FLORIDA COOPERATIVE FISH AND WILDLIFE RESEARCH UNIT GAINESVILLE.
3. Wood, Gerald (1983). The Guinness Book of Animal Facts and Feats. ISBN 978-0-85112-235-9.
4. Wynne 1999, p. 104
5. Bolten, A.B. (2003). "Loggerhead Turtle (Caretta caretta)". NOAA Fisheries. NOAA Fisheries. Archived from the original on May 27, 2010. Retrieved January 31, 2010.
6. Conant 2009, p. 7
7. Wynne 1999, p. 110
8. SeaWorld Parks & Entertainment (2010). "Sea Turtles: Physical Characteristics". SeaWorld/Busch Gardens Animals. Archived from the original on May 27, 2010. Retrieved 2010-05-26. A sea turtle cannot retract its limbs under its shell as a land turtle can.
9. Valente 2007, p. 22
10. Peaker 1975, p. 231
11. Convention on Migratory Species (2004). "Memorandum of Understanding concerning Conservation Measures for Marine Turtles of the Atlantic Coast of Africa". Convention on Migratory Species. UNEP / CMS Secretariat. Archived from the original on May 27, 2010. Retrieved 2010-05-26. The project aims to create a monitoring and protection network for nesting and feeding sites in close collaboration with local communities, fishermen, travel operators and coastal developers.
12. Convention on Migratory Species (2004). "Memorandum of Understanding concerning Conservation Measures for Marine Turtles of the Indian Ocean and South-East Asia". Convention on Migratory Species. UNEP / CMS Secretariat. Archived from the original on May 28, 2010. Retrieved 2010-05-26. In the context of sustainable development, the conservation and management of marine turtles globally and within the Indian Ocean – South-East Asian region presents a formidable challenge.
13. Bullock, Dusty (2008). "What is the Sea Turtle Association of Japan?". Sea Turtle Association of Japan. Sea Turtle Association of Japan. Archived from the original on May 27, 2010. Retrieved 2010-05-26. Our most important activities are counting nesting turtles, and marking them to enable discrimination, using consistent methods throughout Japan.
14. Rees, Alan (2005). "Archelon, the Sea Turtle Protection Society of Greece: 21 Years Studying and Protecting Sea Turtles". Archelon. British Chelonia Group. Archived from the original on May 30, 2010. Retrieved 2010-05-27. Archelon is involved with the turtles, not only through nest management and turtle rehabilitation, but also with stakeholders
15. Marine Research Foundation (2004). "Ongoing Conservation Initiatives". Marine Research Foundation. Marine Research Foundation. Archived from the original on May 30, 2010. Retrieved 2010-05-29. This project aimed to continue to build on Oman’s programme to conduct surveys, develop survey protocols and provide equipment and material and personnel support for Government rangers
16. European Environment Agency (2010). "Legislative instrument details: Cartagena Convention". European Environment Agency. European Environment Agency. Archived from the original on May 31, 2010. Retrieved 2010-05-31. The Cartagena Convention requires Parties to adopt measures aimed at preventing, reducing and controlling pollution of the following areas: pollution from ships; pollution caused by dumping; pollution from sea-bed activities; airborne pollution; and pollution from land-based sources and activities.
17. seaturtle.org (2009-12-11). "Job Board". seaturtle.org. seaturtle.org. Archived from the original on May 28, 2010. Retrieved 2010-05-27. collect biopsy samples for DNA studies, cage nests to prevent egg depredation, record location of nests and non-nesting emergences.
18. Conant 2009, p. 13
19. Whitmeyer, Steven J. (2009). Field geology education: historical perspectives and modern approaches. The Geological Society of America. p. 238. ISBN 978-0-8137-2461-4.

Sources and Credits

  1. (c) Brian Gratwicke, some rights reserved (CC BY), http://www.flickr.com/photos/briangratwicke/3783097766/
  2. (c) Live Zakynthos, some rights reserved (CC BY), https://www.flickr.com/photos/live-zakynthos/4300133049/
  3. (c) Luke Gray, some rights reserved (CC BY-SA), https://www.flickr.com/photos/lukewes/6153317083/
  4. (c) Wikipedia, some rights reserved (CC BY-SA), https://www.inaturalist.org/guide_taxa/705956
  5. (c) Caleb Cam, some rights reserved (CC BY-SA), https://www.inaturalist.org/guide_taxa/705956

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