Diamond-backed Watersnake Nerodia rhombifer

Adult from southern Illinois

Identification: Indiana's largest watersnake is quite distinctive; sporting dark bars and dashes that form a chain-link diamond pattern down its back. Most individuals are relatively light-colored gray to olive-green with red eyes that site more squarely on top of the head than most Indiana snakes. Though most adults are three to four feet (90 cm - 1.2 m) long, some individuals may approach five and a half feet (1.6 m) in length.

Similar Species: Northern watersnakes are common in the same bodies of water as this species, but have large, dark brown blotches instead of narrow bars and bands, as in this species.

Distribution: Diamond-backed watersnakes are found only in the southwestern lowlands along the lower Wabash and Ohio Rivers. They are common along sluggish streams and in oxbow lakes and other permanent aquatic habitats, but also frequent adjacent wetlands.

Distribution Map
Distribution map of Diamond-backed Watersnake (Nerodia rhombifer)
Photographs