Overview
AT A GLANCE
- Common Name: Queen Snake
- Scientific Name: Regina septemvittata
- Category: Reptiles
- Subcategory: Snakes
- Size: 40 to 65 cm (15.7 to 25.6 in); exceptionally up to 90 cm (35.4 in)
- Weight: 80 to 220 g (2.8 to 7.8 oz)
- Lifespan: 8 to 12 years in the wild; up to 14 years in captivity
- Diet: Extreme dietary specialist; feeds almost exclusively on freshly molted (‘soft-shell’) freshwater crayfish
- Habitat: Rocky limestone stream riffles, flat slab boulders, and overhanging willow branches
- Range: Eastern North America, from southwestern Ontario and southern Michigan south through the Ohio and Mississippi valleys, the Appalachian Mountains, and the Piedmont to the Gulf Coast
- Conservation Status: Least Concern
The Queen Snake (Regina septemvittata) is an elegant, highly specialized semi-aquatic natricine colubrid native to the clear, fast-flowing rocky streams and limestone rivers of eastern North America. Instantly distinguished by its slender olive-brown body, creamy-yellow lateral stripes, and an immaculate pale yellow belly striped with four distinct brown lines, this gentle serpent is a dedicated river hunter.
Ecologically, Regina septemvittata is one of the most extreme dietary specialists in the reptilian world: its diet consists almost entirely of newly molted, soft-shell freshwater crayfish. Because hard adult crayfish can easily pinch or injure the snake with their formidable claws, the Queen Snake hunts exclusively during the brief hours when crayfish have shed their rigid exoskeletons and are soft and vulnerable. Because of this strict specialization, the Queen Snake serves as a key bioindicator species: if pollution or siltation harms stream crayfish populations, queen snakes vanish rapidly.
Biology and Physical Characteristics
The morphology of the Queen Snake is characterized by a moderately slender body, a narrow, oval head with small dark eyes, and heavily keeled dorsal scales that give it a textured, non-glossy appearance. Its dorsal coloration is uniform olive-brown, greyish-tan, or dark chocolate-brown, bordered on the lower flanks (scale rows 1 and 2) by a bold, bright cream or lemon-yellow lateral stripe. Its scientific name *septemvittata* (‘seven-striped’) refers to its diagnostic belly pattern: the cream-colored ventral surface is boldly marked by four longitudinal dark brown or blackish stripes, which, combined with the two lateral stripes and a faint dorsal stripe on juveniles, total seven stripes. Its teeth are specialized, possessing relatively short, sturdy dentition optimized for holding soft, slippery crustacean flesh.
Behavior and Ecology
Diurnal, secretive, and aquatic, the Queen Snake spends sunny mornings basking on overhanging tree branches or flat limestone slabs directly above rushing stream riffles. At the slightest vibration, it drops into the water and ducks beneath flat rocks on the riverbed. When hunting, it probes beneath submerged stones and gravel bars, using its keen chemosensory tongue flicking to detect the distinctive chemical scent of a soft-shell crayfish that has recently undergone ecdysis (molting). Upon finding a soft crayfish, the snake swallows it quickly before the crustacean’s new shell can harden. Females are ovoviviparous (giving birth to live young), bearing litters of 5 to 20 independent neonates in late summer.
Conservation and Human Impact
Currently assessed as Least Concern by the IUCN, the Queen Snake remains locally common in pristine Appalachian watersheds. However, in northern and Midwestern portions of its range (such as Ontario, Michigan, and Wisconsin), it is listed as Endangered or Threatened due to heavy agricultural siltation, acid mine drainage, and chemical pollution that kill off sensitive native crayfish populations.
Interesting Factoid
The Queen Snake is an extraordinarily picky eater: it refuses to eat hard-shelled crayfish and hunts almost exclusively for crayfish that have molted their outer shell within the last 24 hours, sniffing them out underwater while their bodies are still completely soft.