Systematics: Originally described by Carolus Linnaeus in 1766 as Testudo imbricata, based on specimens from "Mari Americano, Asiatico" (American and Asian seas). Schmidt (1953) restricted the type locality to Belize, British Honduras. Fitzinger (1843) was the first to use the genus Eretmochelys for this species.

Although many recent authors have abandoned use of Atlantic versus Indo-Pacific Ocean subspecies (Meylan, 2006, Chelon. Res. Monogr. 3: 105–127), the names have not been formally synonymized. Because mitochondrial genome comparisons by Okayama et al. (1999, Chelon. Conserv. Biol. 3: 362–367) suggested genetic divergence between the Caribbean and Indo-Pacific populations, we retain the subspecies names pending further study.

Description: A moderate-sized sea turtle reaching a maximum carapace length (CL) of 90 cm (35.8 inches) and a body mass of 127 kg (280 lb) (Conant and Collins, 1991). The only known Atlantic Hawksbill Sea Turtle from Virginia waters measured 31 cm CL and weighed 4 kg (Keinath and Musick, 1991c).

Morphology: Carapace shieldlike in shape and flattened; middorsal keel present on all but anteriormost vertebral; posterior one-third of carapa- cial margin strongly serrated, except in old adults; marginal scutes 12/12, pleurals 4/4, and vertebrals 5; anteriormost vertebral scute triangular in shape and separates cervical scute from both anterior pleural scutes; carapacial scutes overlap on posterior margins but lie side by side in old adults; plastron large with 2 longitudinal ridges, most prominent in juveniles; bridge with 4 inframarginals lacking visible pores; 4 prefrontal scutes between eyes; head elongated and pointed anteriorly with strong beak on upper jaw; each limb with 2 claws.

Coloration and Pattern: Carapace brown, often with combinations of amber, brown, and black (tortoise shell); old individuals uniformly brown to dark greenish brown; hingeless plastron and undersides of appendages yellow; head yellowish with a large brown patch within each scute, the largest on the dorsum of the head; scales on dorsum of flippers also with brown patches surrounded with yellow.

Sexual Dimorphism: Adult males and females are nearly equal in size (Pritchard and Trebbau, 1984). Adult males possess a thick, elongated tail and a slightly concave plastron (Ernst and Barbour, 1989a).

Juveniles: The carapace of hatchlings and immatures is dark brown to black with strongly overlapping scutes. The plastron, with its 2 prominent keels, is also dark but becomes lighter with age. The edges of the shell and parts of the neck and flippers are light brown changing to yellow with age. At hatching, neonates measured 39-50 mm CL (Ernst and Barbour, 1989a).

Confusing Species: The anteriormost pleural scutes of Loggerheads Sea Turtles (Caretta caretta) and Kemp's Ridley Sea Turtle (Lepidochelys kempii) contact the cervical scute. The Green Sea Turtle (Chelonia mydas) has 2 prefrontal scutes.

Geographic Variation: None in Virginia.

Biology: Atlantic Hawksbill Sea Turtles are marine, never entering freshwater. In the tropics they inhabit rocky coastlines, coral reefs, estuaries, and lagoons with mud substrates (Ernst and Barbour, 1989a). Most do not migrate beyond the tropics, but occasional individuals can be found in temperate waters as far north as Massachusetts. Keinath and Musick (1991c) considered those that entered the Chesapeake Bay as waifs. Because only one has ever been confirmed in Virginia, it is likely that few Atlantic Hawksbill Sea Turtle enter the bay in any given year.

Atlantic Hawksbill Sea Turtles were thought to be omnivores but recent evidence suggests that they specialize on sponges (Meylan, 1988). Shells of these turtles, like those of other species, are often encrusted with barnacles. Sharks prey upon all sizes, and numerous animals, including humans, prey on eggs in nests.

No nests are known or expected on Virginia on isolated beaches (Pritchard and Trebbau, 1984). Females mate with males offshore and move on shore singly to dig nests during high tides, usually at night (Ernst and Barbour, 1989a). Hirth (1980b) reported that they deposited 32-250 eggs per nest and nested as many as seven times in one season at intervals of 13-28 days. The eggs (35-45 mm) are spherical, and took 43-90 days to incubate. As with other sea turtles, the temperature of the nest during incubation determines the sex of the hatchling (Yntema and Mrosovsky, 1982). Hatchlings probably seek refuge in weedlines of the Sargasso Sea in the open ocean (Carr, 1987).

Remarks: The translucent scutes from the carapace of this sea turtle have long been used for "tortoise shell" combs and other trinkets. The primary market today is in the Orient, particularly Japan. Carr (1952) gave a vivid account of how the scutes were removed from living turtles.

Conservation and Management: This species is listed as endangered worldwide under the U.S. Endangered Species Act. In addition to mortality via the tortoise shell industry, hawksbills are killed for food, their eggs are eaten, and small ones are stuffed by tropical peoples to provide curios for tourists (Keinath and Musick, 1991c). In order to protect these turtles, all international trade in products made from their scutes is banned. It is illegal to possess or disturb any parts or whole animals found washed up on beaches. It is also illegal to bring a stuffed specimen or any parts into the United States. All strandings and sightings should be reported to the Virginia Institute of Marine Science so that we can obtain information on how this species uses the Chesapeake Bay.