Northern Diamond-backed Terrapin
Malaclemys terrapin terrapin

Common Name:

Northern Diamond-backed Terrapin

Scientific Name:

Malaclemys terrapin terrapin

Etymology:

Genus:

Malaclemys is derived from the Greek word malakos which means "soft" and klemmys which means "tortoise". This refers to the hinged plastron.

Species:

terrapin is derived from the New Latin word terrapin meaning "turtle".

Subspecies:

terrapin is derived from the New Latin word terrapin meaning "turtle".

Average Length:

females 6 - 9 in. (15.2 - 22.9 cm), males 4 - 5.5 in. (10 - 14 cm)

Virginia Record Length:

8.4 in. (21.3 cm)

Record length:

9.1 in. (23 cm)

Virginia Wildlife Action Plan Rating Tier II - Very High Conservation Need - Has a high risk of extinction or extirpation. Populations of these species are at very low levels, facing real threat(s), or occur within a very limited distribution. Immediate management is needed for stabilization and recovery.

PHYSICAL DESCRIPTION: This turtle is moderately sized reaching a maximum carapace length of approx. 230 mm (9.1 inches). In VA., max known carapace length is 213 mm, max plastron length is 189 mm, and max body weight is 1625 grams. Carapace is wedge-shaped with a posterior serrated edge. It is smooth though some specimens may have keeled vertebral scutes. There are 12 marginals on each side (some individuals on Eastern Shore had 1-2 extra marginals), 4 pleurals on each side and 5 vertebrals. The back shell is usually a light brown or gray but can be dark and almost black. Each scute is marked with dark concentric unevenly shaped "circles". Plastron is hingeless and is 87-92 % the size of the carapace. These turtles are light-colored (orangish to greenish-gray) with (or possibly without) dark markings outlining scutes. Skin is usually gray with dark flecks with a dark mustache present on some individuals. Lips are yellow and eyes are black. Skin is also soft and pliable *10760,11050,11407,11624*.

SEXUAL DIMORPHISM: Females are much larger, weigh more, and have larger heads. There are no sexual differences in color or pattern *10760*. Juveniles are patterned as adults but are light gray with yellow plastron. Average carapace length at hatching is 31.6 +/- 1.0 mm; mass is 7.1-8.7 grams *10760*. This species may be confused with Chrysemys picta though it has 2 yellow spots behind each eye,and red markings on the marginal scutes. Chelydra serpentina has a long saw-toothed tail, and Kinosternon subrubrum has a brown hinged plastron. All sea turtles have flippers and large heads *10760*.

REPRODUCTION: This species breeds and lays eggs in the spring and summer *941*. Mating is in the spring in open water *1420,11050*. Females nest in the dunes from May through July. They lay 4-18 eggs per clutch and may nest 1-2 time per season. Average incubation period is 90 days though some overwintering may occur. Eggs averaged 34.3 +/- 1.6 X 21.2 +/- 0.7 mm in length X width and weighed 8.5 +/- 1.2 grams. Virginia records include: Nesting has been observed in VA. between 30 May and 10 July, average clutch size on barrier islands was 11.1 +/- 2.5 and one historical clutch in Yorktown had 7 eggs. Hatchlings were observed on Ship Shoal island on August 25, 1987 *11050* *10760*. The population ecology of this species is little known. Hildebrand (1932) estimated that M. terrapin live to at least 40 years of age. Males mature earlier (3 yr.) than females (4-7) in other parts of the range. Males outnumber females in most populations and apparently do in estuaries associated with the VA. barrier islands. Lovich and Gibbons (1990) suggested that adult males are numerically dominant because they reach sexual maturity before females.*10760*

BEHAVIOR: They feed mainly on mollusks and crustaceans *941*. This species is the only truly estuarine turtle. They are usually found in coastal, brackish marshes and their tributaries, bays, inlets, and tidal portions of coastal rivers. It can also be found rarely in the Atlantic Ocean. They are unique in the family Emydidae because they possess a nasal salt gland used for excretion of excess salts in body fluids. Though they deal well with pure saltwater they must intake some freshwater occasionally. Hatchlings are not equipped to deal with salinities over 2/3 seawater. It is mostly on the ocean side of the eastern shore, and comparatively fewer are seen in the Chesapeake Bay. Of 84 VA. records, 96.9% occurred in March through October which are the active months. They overwinter in the mud in channels and tidal flats *10760,11624,11050*.

ORIGIN: This is a native species *10760,10949*.

POPULATION PARAMETERS: Recorded longevity is 40 years. The smallest mature female caught had a plastron length of 113 mm and the recorded age of maturation (not recorded from VA) is approximately 4-7 years. Smallest mature male in VA had a plastron length of 91 mm and age at maturity has been put at 3 years in other parts of the range *10760*.

AQUATIC/TERRESTRIAL ASSOCIATIONS: As mentioned above this turtle can tolerate salinity but does require freshwater occasionally especially when young. Eggs are preyed upon by raccoons, skunks and foxes. Adults are preyed upon by raccoons and humans who who eat them as a delicacy, especially in the Asian market *10760,11050*.

References for Life History

  • 941 - Leviton, A., 1970, Reptiles and Amphibians of North America, 250 pgs., Doubleday and Co., New York
  • 10760 - Mitchell, J. C., 1994, The Reptiles of Virginia, 352 pgs., Smithsonian Institution Press, Washington, DC
  • 10949 - Virginia Department of Game and Inland Fisheries, 1995, Collections Database
  • 11050 - Mitchell, J.C., J.M. Anderson, 1994, Amphibians and reptiles of Assateague and Chincoteague Islands, Special Publication #2, 120pp pgs., VA Museum of Nat. History, Martinsville, VA
  • 11407 - Conant, Roger and, Collins, John T., 1998, Peterson Field Guide: Reptiles and Amphibians, Eastern/Central North America, 616 pgs., Houghton Mifflin Company;, Boston
  • 11624 - Mitchell, J. C., 2001, Personal Communication, Expert review for GAP Analysis Project, Mitchell Ecological Research LLC

Photos:

*Click on a thumbnail for a larger version.


Verified County/City Occurrence

Accomack County
Charles City County
Gloucester County
Hampton City
Isle of Wight County
James City County
King William County
New Kent County
Newport News City
Norfolk City
Northampton County
Poquoson City
Portsmouth City
Suffolk City
Virginia Beach City
Westmoreland County
York County
Verified in 17 Counties/Cities.



FROGS

Virginia is home to 28 species of frogs and toads.

SALAMANDERS

We have a large diversity of salamanders consisting of 56 different species and subspecies.

LIZARDS

Virginia is home to 9 native lizard species and two introduced species, the Mediterranean Gecko and the Italian Wall Lizard.

SNAKES

The Commonwealth is home to 34 species and subspecies of snake. Only 3 species are venomous.

TURTLES

Virginia has 25 species and subspecies of turtle. Five of these species are sea turtle.