Eretmochelys imbricata (Hawksbill Sea Turtle)
The common name of this Sea Turtle in English is commonly called Hawksbill Sea Turtle, Hawksbill Turtle, Hawksbill and Thai name called เต่ากระ (Dtao Gra), เต่าปากเหยี่ยว (Dtao Bpak Yieow)
Source: iNaturalist.org; Eretmochelys imbricata (Linnaeus, 1766). Photo by Rafael de la Parra. (CC BY-NC)
เต่ากระ : Eretmochelys imbricata (Linnaeus, 1766)
Eretmochelys imbricata is a species of the Hawksbill Sea Turtle Genus (Eretmochelys) within the Sea Turtle Family (Cheloniidae), Superfamily Chelonioidea, in the Suborder Cryptodira, in the Turtles Order (Testudines), in the Reptile Class (Reptilia), in the Chordate Phylum (Chordata) in the Animal Kingdom (Animalia).
Published in Linné, C. Von [= Linnaeus, C.]. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio duodecima, reformata. Laurentii Salvii, Stockholm, Holmiae. 1-532 pp. (1766).
Genetic analyses in the Atlantic and Indo-Pacific indicate that nesting populations comprise separate and identifiable stocks that should be treated as separate management units (Bass et al. 1996, Bowen et al. 1996, Bowen et al. 2007).
Hawksbill aggregations on foraging grounds comprise animals from multiple nesting populations and often include animals from distant rookeries (Broderick et al. 1994, Bowen et al. 2007).
The name Eretmochelys is formed from the Greek words eretmon (oar) and chelys (tortoise, turtle), and refers to the oarlike limbs of this marine turtle.
The specific epithet 'imbricata' is derived from the Latin imbricatus (overlapping, like roofing tiles and shingles) and refers to the overlapping carapacial scutes of juveniles and young adults of this species.
Subspecies
- Eretmochelys imbricata bissa (Rüppell 1835)
- Eretmochelys imbricata imbricata (Linnaeus, 1766)
Geographic Range
The Hawksbill has a circumglobal distribution throughout tropical and, to a lesser extent, subtropical waters of the Atlantic Ocean, Indian Ocean, and Pacific Ocean. Hawksbills are migratory and individuals undertake complex movements through geographically disparate habitats during their lifetimes.
Hawksbill nesting occurs in at least 70 countries, although much of it now only at low densities. Their movements within the marine environment are less understood, but Hawksbills are believed to inhabit coastal waters in more than 108 countries (Groombridge and Luxmoore 1989, Baillie and Groombridge 1996; see Regional Overviews in Supplementary Material).
Habitats
Hawksbills nest on insular and mainland sandy beaches throughout the tropics and subtropics. They are highly migratory and use a wide range of broadly separated localities and habitats during their lifetimes (for review see Witzell 1983).
Available data indicate that newly emerged hatchlings enter the sea and are carried by offshore currents into major gyre systems where they remain until reaching a carapace length of some 20 to 30 cm.
At that point they recruit into a neritic developmental foraging habitat that may comprise coral reefs or other hard bottom habitats, sea grass, algal beds, or mangrove bays and creeks (Musick and Limpus 1997) or mud flats (R. von Brandis unpubl. data).
As they increase in size, immature Hawksbills typically inhabit a series of developmental habitats, with some tendency for larger turtles to inhabit deeper sites (van Dam and Diez 1997, Bowen et al. 2007).
Once sexually mature, they undertake breeding migrations between foraging grounds and breeding areas at intervals of several years (Witzell 1983, Dobbs et al. 1999, Mortimer and Bresson 1999).
Global population genetic studies have demonstrated the tendency of female sea turtles to return to breed at their natal rookery (Bowen and Karl 1997), even though as juveniles they may have foraged at developmental habitats located hundreds or thousands of kilometers from the natal beach.
While Hawksbills undertake long migrations, some portion of immature animals may settle into foraging habitats near their beaches of origin (Bowen et al. 2007).
Roles in the Ecosystem
Like other species of sea turtles, Hawksbills contribute to marine and coastal food webs and transport nutrients within the oceans (Bouchard and Bjorndal 2000). Hawksbills are important components of healthy coral reef ecosystems and are primarily spongivorous in the Caribbean (Meylan 1988), but more omnivorous in the Indo-Pacific (review by Bjorndal 1997).
They consume relatively large amounts of algae in northern Australia (Whiting 2000 cited in S. Whiting in litt. to J. Mortimer 4 Jun 2007), soft corals in the Great Barrier Reef region (C. Limpus unpublished data), and other combinations of forage depending on habitat (in Seychelles, J. Mortimer and R. von Brandis unpublished data; in Barbados, B. Krueger unpublished data).
At sites where they are primarily spongivorous, Hawksbills have been found to support healthy reefs by controlling sponges which would otherwise out-compete reef-building corals for space (Hill 1998, León and Bjorndal 2002, Bjorndal and Jackson 2003).
Synonym
- Testudo imbricata Carolus Linnaeus (1766)
- Eretmochelys imbricata imbricata Carolus Linnaeus (1766)
- Testudo imbricata George Shaw & Frederick Polydore Nodder (1797)
- Chelonia radiata Georges-Frédéric Cuvier (1829)
- Testudo imbricata Georges-Frédéric Cuvier (1831)
- Chelonia pseudo mydas René-Primevère Lesson (1834)
- Chelonia pseudo caretta René-Primevère Lesson (1834)
- Chelonia Imbricata André Marie Constant Duméril & Gabriel Bibron (1835)
- Eretmochelys imbricata bissa E. Rüppell (1835)
- Caretta bissa E. Rüppell (1835)
- Eretmochelys imbricata Jean Louis Rodolphe Agassiz (1857)
- Eretmochelys squamata Jean Louis Rodolphe Agassiz (1857)
- Caretta rostrata Charles Frédéric Girard (1858)
- Caretta squamosa Charles Frédéric Girard (1858)
- Caretta squamata Robert Swinhoe (1863)
- Onychochelys kraussi John Edward Gray (1873)
- Chelone imbricata George Albert Boulenger (1889)
- Eretmochelys squamosa Leonhard Hess Stejneger (1907)
- Eretmochelys squamosa Samuel Walton Garman (1908)
- Eretmochelys squamata Thomas Barbour (1918)
- Eretmochelys imbricata imbricata Robert Mertens & Lorenz Müller (1928)
- Eretmochelys imbricata squamata Archie Fairly Carr (1942)
- Eretmochelys imbricata bissa Malcolm Arthur Smith & Edward Harrison Taylor (1950)
- Eretmochelys imbricata Robert Cyril Stebbins (1985)
- Eretmochelys imbricata bissa Robert Cyril Stebbins (1985)
- Eretmochelys imbricata Roger Conant & Joseph Thomas Collins (1991)
- Eretmochelys imbricata Engelmann et al. (1993)
- Eretmochelys imbricata Frank Glaw & Miguel Vences (1994)
- Eretmochelys imbricata squamata Danny Meirte (1999)
- Eretmochelys imbricata Harold Cogger (2000)
- Eretmochelys imbricata imbricata Brian I. Crother (2000)
- Eretmochelys imbricata bissa Brian I. Crother (2000)
- Eretmochelys imbricata Jean-François Trape; Sébastien Trape & Laurent Chirio (2012)
- Eretmochelys imbricate Tanya Chan-Ard et al. (2015)