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diamond-backed watersnake

diamond-backed watersnake (Nerodia rhombifer) Photo © Brad M. Glorioso

Features and Behaviors

The diamond-backed watersnake averages 30 to 48 inches in length. Its back has a pattern of dark, chainlike markings on a background of lighter brown or dirty yellow. The yellow belly is marked with black or brown spots. The scales are keeled (ridged).

The diamond-backed watersnake may be found in the southern one-third of Illinois and the Mississippi and Illinois river valleys in the state. This species lives in lakes, rivers, ditches, ponds, sloughs and swamps. The diamond-backed watersnake is aquatic but may be seen basking in the sunshine on limbs over water. It is essentially nocturnal in the hot summer months, but individuals may be active during the day in spring and fall. This snake may flatten its body when disturbed and/or release large amounts of nasty-smelling musk from glands at the base of the tail. Mating occurs in spring. About 14 to 60 young per female are born in late summer or early fall, the number of young directly related to the size and age of the female. This animal eats fishes and amphibians.

Illinois Range


​Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Natricidae

Illinois Status: common, native