Drymarchon couperi

The eastern indigo snake (Drymarchon couperi) is a species of large, non-venomous snake in the family Colubridae. The species is native to the eastern United States. It is the longest native snake species in the U.S. The eastern indigo snake has uniform blue-black dorsal and lateral scales, with some specimens having a reddish-orange to tan color on the throat, cheeks, and chin. This snake received its common name from the glossy iridescent ventral scales which can be seen as blackish-purple in bright light. This smooth-scaled snake is considered to be the longest native snake species in the United States. The longest recorded specimen measured 2.8 m (9.2 ft) in total length (including tail). Unlike many snakes, mature male indigo snakes are slightly larger than females. A typical mature male measures 1.2–2.36 m (3.9–7.7 ft) in total length, with a reported average of 1.58 m (5.2 ft), and weighs 0.72–4.5 kg (1.6–9.9 lb), reportedly averaging 2.2 kg (4.9 lb). Meanwhile, a mature female typically measures around 1.1–2 m (3.6–6.6 ft) in total length, averaging 1.38 m (4.5 ft), and weighs 0.55–2.7 kg (1.2–6.0 lb), averaging 1.5 kg (3.3 lb). In specimens over 2.6 m (8.5 ft), these snakes can weigh up to 5 kg (11 lb). Although the indigo snake is similar in average body mass, extremely large specimens of the bulky, co-occurring venomous eastern diamondback rattlesnake can outweigh them. The eastern indigo snake was first described by John Edwards Holbrook in 1842. For many years the genus Drymarchon was considered monotypic with one species, Drymarchon corais, with 12 subspecies, until the early 1990s when Drymarchon corais couperi was elevated to full species status according to The Society for the Study of Amphibians and Reptiles, in their official names list. The generic name, Drymarchon, roughly translates to “lord of the forest”. It is composed of the Greek words drymos (Δρυμός), meaning 'forest', and archon (ἄρχων), meaning 'lord' or 'ruler'. The specific name is a latinization of the surname of American planter James Hamilton Couper (1794-1866). Couper brought Holbrook the type specimen from south of the Altamaha River in Wayne County, Georgia.