Rainbow Snake, Eel Moccasin



Scientific name: Farancia erytrogramma erytrogramma (PALISSOT DE BEAUVOIS in SONNINI & LATREILLE 1802)
* Currently accepted name

* scientific names used through time

  • Coluber erytrogrammus – PALISSOT DE BEAUVOIS in SONNINI & LATREILLE 1802
  • Coluber erythrogrammus – DAUDIN 1803
  • Natrix erythrogrammus – MERREM 1820
  • Homalopsis erythrogrammus – BOIE 1827
  • Helicops erythrogrammus – WAGLER 1830
  • Abastor erythrogrammus – GRAY 1849
  • Callopisma erythrogramma – DUMÉRIL 1853
  • Homolopsis parviceps – BLYTH 1854: 301 (fide BAUER & DAS 1999)
  • Abastor erytrogrammus – THEOBALD 1868
  • Hydrops erythrogrammus – SCLATER 1891
  • Abastor erythrogramus – COCHRAN 1952 (fide LINER 2004)
  • Farancia erytrogramma erytrogramma – CONANT 1975

Average adult size is 40-54 inches (101-137 cm), record is 66 inches (167.6 cm). Adults are large and thick bodied. The back is iridescent blue-black with a bright red stripe down the middle and an additional reddish-pink stripe on each side. The lower sides of the body are yellow or pink fading into the red belly. Black spots on each belly scale form three lines of dots down the belly. The chin and throat are yellow. The tail tip ends in a pointed, horny scale. The scales are mostly smooth, except on the lower back and sides where they are weekly keeled. There are 19 dorsal scale rows at midbody. The pupil is round. Juveniles are similar in appearance to adults.


A. Top of the head
B. Underside of the head (chin and throat)
C. Front (face view) of the head
D. Smooth scales
E. Elongated scales below the tail (subcaudal scales) are typically divided
F. Side of the head

Range: In Florida, it occurs throughout the panhandle and northern peninsula, south along the St. John's River to northern central Florida. Apparently disjunct populations have been reported from the Tampa Bay region. Outside of Florida, it ranges along the Atlantic Coastal Plain from eastern Louisiana to southern Maryland.

Habitat: Uncommon to rare, it mainly inhabits clear waters of springs and rivers. It is also sometimes observed near creeks, lakes, cypress swamps, marshes, and tidal mudflats.


Comments: HARMLESS (Non-Venomous). The Rainbow Snake is rarely encountered, possibly due to its secretive subterranean behavior. It is aquatic and a good burrower. It spends much of its life under floating vegetation and within banks on water's edges. It has been found under shorline debris including spanish moss and logs. It has been plowed up in fields several hundred yards from the nearest water. It is sometimes observed crossing roads at night, especially during or after heavy rains. If captured, it may press its pointed tail tip into one's hand. The tail is totally harmless and cannot sting or even break the skin.

It specializes in eating eels (Anguilla rostrata), earning it the nickname "Eel Moccasin." However, juveniles may feed on amphibians such as tadpoles, and other fishes.

It lays eggs. From 10-52 eggs are deposited in moist areas. Females have been found coiled around their clutches of eggs.

Comparison with other species: Mud Snakes (Farancia abacura) and Swamp Snakes (Seminatrix pygaea) lack the Rainbow Snake's reddish-pink dorsal stripes.