Systematics: Originally described as Testudo coriacea by Domenico Vandelli in a published letter (Vandelli, 1761) to Carolus Linnaeus from a specimen collected from "maris Tyrrheni oram agro Lauren- tiano" (Iverson, 1992). The type locality was restricted to "Laurentum, between Lido de Ostia and Tor Paterno, shore of the Tyrrhenian Sea, Italy" (Bour and Dubois, 1983). Linnaeus (1766) had long been considered the author of the name Testudo coriacea, but Bour (1979) discovered that Vandelli first proposed it to Linnaeus. Recent changes in the International Code of Zoological Nomenclature allowed Vandelli to be credited as the author of the scientific name (see Bour and Dubois, 1983, and Smith and Rhodin, 1986, for discussions of this problem). The genus Der- mochelys was first used for this species by Blain- ville (1816). Some authors (e.g., Ernst and Barbour, 1989a) have recognized two subspecies, one in the Atlantic Ocean (D. coriacea coriacea) and one in the Pacific Ocean (D. coriacea schlegelii), whereas others (e.g., Pritchard, 1980; Iverson, 1992) have recognized no subspecies.

Description: The largest living sea turtle, reaching a maximum carapace length (CL) of 244 cm (96 inches) and a body mass of 914 kg (2,016 lb; Morgan, 1989). In 213 cm (presumably CL) and weighed 317 kg (Reed, 1957b). Most specimens have measured 124.0-182.9 cm CL (Lutcavage, 1981).

Morphology: Carapace somewhat teardrop in shape with 7 longitudinal keels that divide carapace into 8 sections; shell consists of a leathery skin in which is embedded a mosaic of many small bones; epidermal scutes and hard bony shell absent; shell lacks all but vertebral and rib bones; ribs are embedded beneath shell.

Coloration and Pattern: Carapace black to bluish black with a highly variable number of white spots; plastron whitish with 5 longitudinal ridges made of enlarged bones in the skin; head, neck, and limbs black to dark green with a variable number of white blotches. The large head cannot be withdrawn into the shell. The forelimbs are modified into very large flippers (> body length). The smaller hind limbs are paddlelike. No limbs possess claws.

Sexual Dimorphism: Adult male leatherbacks have a concave plastron and tails that are longer than their hind limbs (Ernst and Barbour, 1972). The tails of adult females do not extend beyond the hindlimbs.

Juveniles: Hatchlings are black to dark brown, and the keels on the carapace and the margins of the flippers are white to yellow (Ernst and Barbour, 1972), There are several small scales on the head and limbs, which fall off after a few weeks of age (Pritchard, 1980). Hatchlings were 55-63 mm CL (ave. = 58.7) (Hirth, 1980b).

Confusing Species: All other marine turtles have scutes (plates) covering a bony shell and claws on the limbs.

Geographic Variation: None in Virginia.

Biology: Adults and juveniles are pelagic and spend most of their lives in the ocean. Only females come ashore and then only to nest. Few are seen alive in Virginia waters. During the period of 1979-1986, Virginia Institute of Marine Science (VIMS) personnel observed 23 Leatherback Sea Turtles in the Chesapeake Bay (Barnard et al., 1989). They are more commonly seen at the mouth of the bay and in the Atlantic Ocean off Virginia's shores than in the bay proper (Musick, 1988; Barnard et al., 1989). Subadults and adults are occasionally seen in estuaries and stranded on beaches, but juveniles are seldom seen anywhere (Pritchard and Trebbau, 1984).

Leatherback Sea Turtles forage primarily on jellyfish, but occasionally on squid, crustaceans, some fish, and seaweed (Ernst and Barbour, 1989a). In Virginia, leatherbacks feed primarily on (Chrysaora qumquecirrha) (Musick, 1988; Keinath et al., 1987). Their jaws are not constructed to crush hard prey, but instead have a simple scissorlike cutting edge (Pritchard and Trebbau, 1984). Various birds, dogs, cats, and pigs prey on the eggs; these and fish and sharks are known to eat hatchlings (Pritchard, 1971). Humans have killed Leatherback Sea Turtles for their oils, eggs, and meat (Pritchard, 1971, 1982), and killer whales (Orcinus orca) are known to kill them for food (Caldwell and Caldwell, 1969). Causes of mortality in Virginia waters are injury from boat propellers and entanglement in fishing nets (Lutcavage, 1981; Musick et al., 1985). Commensals on the shells include several species of barnacles, isopods, remoras, and sharksuckers (Eckert and Eckert, 1988).

There are no records of nesting Leatherback Sea Turtles in Virginia. Mating apparently takes place in the ocean in temperate regions, and females migrate to specific tropical beaches for colonial nesting (Pritchard, 1980; Eckert and Eckert, 1988). Females throughout the range laid 35-142 eggs (ave. = 88.1) per nest (Hirth, 1980b). Annual clutch frequency for individual females studied varied from 1 to 10, with an internesting interval of about 9-10 days (Eckert and Eckert, 1988; Tucker and Frazer, 1991). Eggs are spherical, and were reported to be 50-65 mm in diameter (ave. = 52.7) and 70-80 g each; natural incubation period was 51-74 days (Hirth, 1980b).

Almost nothing is known of the population biology of this turtle. Males are seldom captured, and most known data on size and behavior are from juveniles and females. Pritchard (1982) estimated a world population of 115,000 mature females, but noted the extensive slaughter on a Mexican beach and recommended keeping this species on the endangered list. Barnard et al. (1989) reported 21 dead leatherbacks from the Potomac River southward and along Virginia's Atlantic coast between 1979 and 1988. One live leatherback (a 133.4-cm-CL female) was captured on 30 May 1985 in Mobjack Bay, tagged, and released. On 22 July 1986 local fishermen in the Gulf of Guacanayabo, southern Cuba, captured and killed this turtle. It traveled a minimum distance of 2,168 km (Keinath and Musick, 1990).

Ernst and Barbour (1972) reported that the Leatherback Sea Turtle flails its flippers violently and vocalizes when captured. Carr (1952) said that attacked Leatherback Sea Turtles emitted sounds he described as pathetic wails, groans, roars, and bellows. Vocalizations made by females when nesting are sighs and a sharper sound, not unlike a human belch (Mrosovsky, 1972). Leatherbacks dive to a depth of 475 m or more, about the depth attained by bottle-nosed dolphins (Tursiops truncatus) (Eckert et al., 1986). Leatherback Sea Turtles are able to maintain their body temperature several degrees higher than that in surrounding waters, largely because of heat exchange mechanisms in the front and rear flippers, the fat layer below the skin, and the large body size (Standora et al., 1984). This explains their ability to migrate into cold waters in upper latitudes, where they feed on cold-water jellyfish.

Remarks: Chesapeake Bay fishermen use the name "rubber- back" for this species (Lutcavage, 1981). A 23 May 1977 article in the Richmond News Leader used the name "trunkback turtle."

Nothing is known of the ecology or behavior of leatherbacks in Virginia, nor of its ecological role in estuarine systems.

The preponderance of clear plastic debris in the oceans has caused a substantial increase in the mortality of Leatherback Sea Turtles. Because they look like jellyfish, plastic bags, jugs, and sheets are eaten by these turtles. The plastic causes intestinal blockage and starvation (Fritts, 1982).

Conservation and Management: The Leatherback Sea Turtle is listed as endangered under the U.S. Endangered Species Act. VIMS personnel have been monitoring strandings and sightings in Virginia waters since 1979. Reports of stranded Leatherback Sea Turtle should be directed to them. Conservation efforts should be directed at the nesting beaches and toward a reduction of killing by humans for any reason. Dumping of plastic items in the ocean should be banned. Keinath and Musick (1991e) discussed threats to this turtle and provided recommendations for its conservation.