Venomous and Poisonous Animals
Biology & Clinical Management

Micrurus sp. and Micruroides euryxanthus

primarily nocturnal, but also seen during the day

ground-dwelling

stony and sandy arid areas

conspicuous warning colouring consisting of black, red and yellow (or beige, or white) cross bands (a number of harmless colubrids also have this colouring, but in Micrurus the red and yellow bands are adjacent, while in colubrids the red and black rings are adjacent)

when threatened, the end of the tail is raised in the air and moved back and forth; the head is sometimes hidden under the coils of the body

generally non-aggressive behaviour; only rarely the cause of snakebites

nocturnal in warm weather, diurnal in cool

ground-dwelling

A. contortrix primarily in deciduous forests, A. piscivorus is a semi-aquatic species found in bodies of water or swamps

sturdy body; A. piscivorus up to

1.8 m long

A. piscivorus does not try to flee when threatened; head is thrown back and mouth is opened wide, so that the white interior of the mouth becomes visible; vibration of the tip of the tail

A. contortrix is the most common cause of venomous snakebites in the USA; A. piscivorus bites common in the Mississippi valley and along the Gulf Coast of the USA

Crotalus sp.

nocturnal in warm weather, diurnal in cool

ground-dwelling

primarily in arid areas, from the lowlands to mountains;

C. horridus in wooded regions and swamps

stout body with characteristic rattle on the end of the tail; smaller species around 60 cm, the largest up to 1.5 m long

a typical dry and high warning sound is produced by vibration of the rattle; during this process the body is formed into a tightly coiled S-shape

accidents common in the USA; these are often self-inflicted, i.e. the result of unnecessary handling of these snakes; men are most common victims

Sistrurus sp.

primarily nocturnal, but also seen during the day

ground-dwelling

S. miliarius in dry habitats,

S. catenatus in damper habitats

as for Crotalus sp., but on average smaller (<1 m); also have a rattle

as for Crotalus sp.

accidents less common than with Crotalus sp.