
A small species with adults usually growing to 40-60 cm in length. Maximum reported length are 78.8 cm. There were reports of a specimen of S. m. barbouri measuring 80.3 cm, but it had been in captivity for over 12 years. The largest S. m. barbouri reported was a specimen measuring 63.8 cm from St. Petersburg, Florida.It has been suggested that in some populations males may be larger than females, but a later study in 1996 did not find sexual dimorphism of any kind in a population in Volusia County, Florida.
The midbody rows of dorsal scales usually number 23. The dorsal pattern consists of a series of oval or subcircular spots with reasonably regular edges. The spots on the flanks are mostly round and not much higher than they are wide. Belly pigmentation towards the rear is more limited to indistinct blotches found on pairs of adjacent scales
Found in the southeastern United States from southern and eastern North Carolina, south through peninsular Florida and west to eastern Texas and Oklahoma. The type locality given is "Carolina." Schmidt (1953) proposed that this be restricted to "Charleston, South Carolina.
This species reportedly inhabits flatwoods, sandhills, mixed forests, flood plains, and is also found near lakes and marshes
Usually seen in the summer sunning themselves or crossing the road later in the day. The tiny rattle makes a buzzing sound that can only be heard from a few feet. Some individuals are very aggressive and will strike furiously, while others seem lethargic and do not even attempt to rattle
Its diet includes small mammals and birds, lizards, insects and frogs, as well as other snakes
Since this species in unable to produce much venom, it is unlikely that it is able to deliver a fatal bite to a human adult. Brimley wrote that although it was too small to be really dangerous, its bite "will give the victim quite an unpleasant time for several days." However, bites involving children have resulted in prolonged hospitalization and there are also reports of necrosis.
These snakes have strongly hemorrhagic and tissue toxic venom, but it devoid of any neurotoxins. It is somewhat different in that it contains substantial amounts of serotonin and related tryptamine compounds. Antivenin does not appear to be effective in the treatment of these bites, although CroFab does seem to do a better job than ACP, at least in some animal models.
| Subspecies | Common name | Geographic range |
|---|---|---|
S. m. barbouri |
Dusky pigmy rattlesnake |
The United States from extreme southern South Carolina through southern Georgia, all of Florida, west through southern Alabama and southeastern Mississippi. |
S. m. miliarius |
Carolina pigmy rattlesnake |
The United States from extreme southern South Carolina, northwards into eastern North Carolina as far as Hyde County and west through central Georgia and central Alabama. |
S. m. streckeri |
Western pigmy rattlesnake |
The United States in Mississippi (except for southeast of the Pearl River Valley), west through Louisiana into eastern Texas, and north into southeastern Oklahoma, Arkansas, southern Missouri and southwestern Tennessee. |