Eastern Mud Snake
Farancia abacura abacura

** Harmless **

Common Name:

Eastern Mud Snake

Scientific Name:

Farancia abacura abacura

Etymology:

Genus:

Farancia has no know meaning.

Species:

abacura is derived from the Latin word abacus which means "counting board".

Subspecies:

abacura is derived from the Latin word abacus which means "counting board".

Vernacular Names:

Checkered snake, dart snake, eastern horn snake, hoop snake, North American red-bellied snake, stinging snake, thunder snake.

Average Length:

40 - 54 in. (102 - 137 cm)

Virginia Record Length:

58.6 in. (148.9 cm)

Record length:

85.1 in. (207 cm)

Virginia Wildlife Action Plan Rating Tier IV - Moderate Conservation Need - The species may be rare in parts of its range, particularly on the periphery. Populations of these species have demonstrated a significant declining trend or one is suspected which, if continued, is likely to qualify this species for a higher tier in the foreseeable future. Long-term planning is necessary to stabilize or increase populations.

PHYSICAL DESCRIPTION: The adults is shiny black and smooth above with the black extending in bars across the belly. The basic belly color is pink or red which extends up along the sides as bars or triangles. The body is stout and muscular and the head is barely distinct from the neck. The tail tip is stiff and blunt. The Juvenile is similar to the adults, but reddish side markings may join across the anterior portion of the back to form complete bands. The tail tip is sharp *1006*. The dorsal scales are mostly smooth except above the anal region where they are keeled. There are 19 scale rows and the anal plate is usually divided but occasionally single. The loreal scale is present but the preocular scale is absent *1006*. The longevity record for the mud snake is 14 years and 2 months *11523*. This species is from 7 inches at birth to over 6 1/2 feet at adulthood. Most adults are between 3 and 5 feet long *1006*. In Virginia, max known SVL is 1350 mm (53.1 in.) and total length is 1489 mm (58.6 in.). Tail length/total length ratio averages 13.6+/-3.4% (7.2-17.9%, n=18). Scutellation: ventrals 169-199 (avg. = 184.9+/-10.1, n=19); subcaudals 31-51 (avg. 40.6-+/-6.0, n=19); ventrals + subcaudals 200-237 (avg. = 225.5+/-8.3, n=19); dorsal scales smooth; scale rows 19 (100%, n=16) at midbody; anal plate divided; infralabials 8-8 (26.7%, n=15), 8-9 (33.3%), one abnormal specimen with 6-8 (6.7%); supralabials 7-7 (82.4%, n=17) of combinations of 7-8 (17.6); loreal present, twice as long as wide; no preoculars; postoculars 2-2; temporals usually 1+2/1+2 (83.3%, n=18), other combinations of 1-3 (16.7%).

COLORATION and PATTERN: dorsum shiny black; dorsal head scales black variously outlined in cream; venter red to pink; ventral coloration extends upward onto lateral portion of the body, and doresal black pigmentation extends onto venter giving the appearance of alternating red and black lateral blotches or bars; chin, labial scales, and throat yellow; venter of neck red; black spots on lower sides of neck; a row of black spots occurs on infralabials and supralabials. This is a stout bodied snake with a somewhat flattened head and keratinized point on the tip of the tail.*10760* Sexual Dimorphism: there is no sexual dimorphism in pattern and color in this species. Adult females are larger (avg. SVL = 1097.7+/-164.8 mm, 863-1350, n=7) than males (avg. SVL = 900.9+/-159.8 mm, 725-1106, n=8). Sexual dimorphism index is 1.22. Females have relatively shorter tails (tail length/total length ratio: female avg. = 10.3+/-2.0%, 7.2-13.0, n=8; male avg. = 16.4+/-0.9%, 15.2-17.9, n=10). Males have fewer ventral scales (avg. = 177.9+/-6.6, 169-195, n=11) than females (avg. = 194.5+/-4.4, 185-189, n=8), but more subcaudals (male avg. = 44.4+/-5.0, 31-51, n=11; female avg. = 35.5+/-2.2, 31-39, n=8). Ventrals + subcaudals averages higher in females (avg. = 230.0+/-5.1, 220-235, n=8) than males (avg. = 222.3+/-8.9, 200-237, n=11).*10760*

JUVENILES: Juvenile F. abacura are colored and patterned as adults. They are 180-260 mm SVL at hatching in Florida and Louisiana. Hatching size is unknown in Virginia.*10760* Confusing Species:This species may be confused with the black racer and the eastern ratsnake because of the black dorsum. These 2 species lack the red venter, the lateral alternating red and black coloration, the yellow chin, and black spots in the labial scales. Nerodia sipedon may also be nearly black with reddish markings laterally, but this species has strongly keeled scales and crossbands and blotches on the dorsum. Rainbow snakes, Farancia srytrogramma, sometimes found in the same habitats, are morphologically similar but have longitudinal red and black stripes.

REPRODUCTION: This species lay 100 or more eggs during the summer. The average clutch size is between 25 and 50. The young hatch in September. They usually do not care for the eggs once they have been layed although a few have been observed coiled around their eggs until they hatched *1006*. Females excavate a chamber in moist soil, usually under a log or in a mound above water level. They remain with the eggs until hatching, presumably to protect them against predators. Eggs (30-35 x 19.5-25 mm) and newly hatched juveniles (180-234 mm total length) have been found July through October. In South Carolina, young of the year juveniles (180-260 mm SVL, avg. = 223-15) entered aquatic habitats March-May and September-October. The population ecology of this species has not been studied.*10760*

BEHAVIOR: This snake is seldom seen and they are quite secretive. Much time is spent burrowing in mud muck and sand. They are among the most aquatic of Virginia's snakes and are excellent swimmers. They are sometimes seen in the open, especially at night or during rains. When captured, they rarely bite. For defensive behavior, this species tries to hide its head under its coil and will poke at its attacker with the blunt tipped tail. This species finds amphiumas and sirens the favorite prey. They also consume tadpoles, frogs, small salamanders and fish. They will use the end of the tail to position the prey for swallowing *1006*. This species has been observed, by Tom Thorp, on wet roads during and after heavy rains *11523*.

AQUATIC/TERRESTRIAL ASSOCIATIONS: Predation by large animals accounts for a significant loss of the eggs and young *1006*.

References for Life History

  • 1006 - Linzey, D.W., M.J. Clifford, 1981, Snakes of Virginia, Univ. of Virginia Press, Charlottesville, VA
  • 10760 - Mitchell, J. C., 1994, The Reptiles of Virginia, 352 pgs., Smithsonian Institution Press, Washington, DC
  • 11523 - Thorp, T.J., 2001, Personal Communication, Expert Review for GAP Analysis Project, Three Lakes Nature Center and Aquarium

Photos:

*Click on a thumbnail for a larger version.


Verified County/City Occurrence

Amelia County
Charles City County
Chesapeake City
Greensville County
Isle of Wight County
New Kent County
Prince George County
Southampton County
Suffolk City
Sussex County
Virginia Beach City
Verified in 11 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.