Adults of L. rigida are on average 16 inches (about 41 cm) in total length (including tail), and are heavy-bodied.[4] The maximum recorded total length for this
species is 31+3⁄8 inches (80 cm).[5]
L. rigida is olive brown
dorsally. Additionally, two blackish dorsal stripes may or may not be present. The upper lips (labial scales) are yellow. Ventrally, it is yellow with two parallel series of black spots, which merge anteriorly into a single series. The ventral surface of the tail may have a median black line, or it may be unmarked.
The
dorsal scales are arranged in 19 rows at midbody. They are strongly keeled, except for the first two rows. The first row (adjacent to the
ventrals) is smooth, and the second row is weakly keeled. The ventrals number 132-142. The
anal plate is divided. The
subcaudals number 51-71, and are divided.[6]
^Conant R (1975). A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition. Boston: Houghton Mifflin Company. xviii + 429 pp. + Plates 1-48.
ISBN0-395-19979-4 (hardcover),
ISBN0-395-19977-8 (paperback). ("GLOSSY WATER SNAKE Natrix rigida ", pp. 150-151 + Plate 21 + Map 108).
^Schmidt KP, Davis DD (1941). Field Book of Snakes of the United States and Canada. New York: G.P. Putnam's Sons. 365 pp. ("STRIPED WATER SNAKE.–Natrix rigida Say", pp. 213-214, Figure 69).
^Smith HM, Brodie ED Jr (1982). Reptiles of North America: A Guide to Field Identification. New York: Golden Press. 240 pp.
ISBN0-307-13666-3 (paperback),
ISBN0-307-47009-1 (hardcover). ("GLOSSY CRAYFISH SNAKE Regina rigida ", pp. 158-159).
^Boulenger GA (1893). Catalogue of the Snakes in the British Museum (Natural History). Volume I., Containing the Families ... Colubridæ Aglyphæ, part. London: Trustees of the British Museum (Natural History). xiii + 448 pp. + Plates I-XXVIII. ("Tropidonotus rigidus ", p. 240).
Further reading
Behler JL, King FW (1979). The Audubon Society Field Guide to North American Reptiles and Amphibians. New York: Alfred A. Knopf. 743 pp., 657 color plates.
ISBN0-394-50824-6. ("Glossy Crayfish Water Snake (Regina rigida)", pp. 647-648 + Plate 474).
Conant R, Bridges W (1939). What Snake Is That? A Field Guide to the Snakes of the United States East of the Rocky Mountains. (With 108 drawings by Edmond Malnate). New York and London: D. Appleton-Century Company. Frontispiece map + viii + 163 pp. + Plates A-C, 1-32. ("STRIPED WATER SNAKE Natrix rigida ", p. 97 + Plate 17, figure 50).
Powell R, Conant R,
Collins JT (2016). Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 47 plates, 207 figures.
ISBN978-0-544-12997-9. ("GLOSSY SWAMPSNAKE Liodytes rigida ", p. 414 + Plate 41).
Say T (1825). "Descriptions of three new species of COLUBER, inhabiting the United States". J. Acad. Nat. Sci. Philadelphia4 (2): 237-241. (Coluber rigidus, new species, pp. 239–240).
Stejneger L,
Barbour T (1917). A Check List of North American Amphibians and Reptiles. Cambridge, Massachusetts: Harvard University Press. 125 pp. ("Natrix rigida ", p. 95).