if fed primarily fish but must be supplemented with vitamin B1. Larger specimens will often consume rodents.. References 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. . (Nerodia rhombifera, pp. 636-637 + Plate 574). Cagle FR (1937). "Notes on Natrix rhombifera as observed at Reelfoot Lake". Journ. Tennessee Acad. Sci. 12: 179-185. Clay WM (1938). "A new water snake of the genus Natrix from Mexico". Annals of the Carnegie Museum 27: 251-255. (Natrix rhombifera blanchardi, new subspecies). Conant R (1953). "Three new water snakes of the genus Natrix from Mexico". Natural History Miscellanea 126: 1-9. (Natrix rhombifera werleri, new subspecies, p. 4). 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. Frontispiece map + viii + 163 pp. + Plates A-C, 1-32. (Natrix rhombifera rhombifera, p. 96 + Plate 17, figure 48). Gibbons JW, Dorcas ME (2004). North American Water Snakes: A Natural History. (Foreword by Roger Conant). Norman, Oklahoma: University of Oklahoma Press. 496 pp. . Hallowell E (1852). "Descriptions of new species of reptiles inhabiting North America". Proc. Acad. Nat. Sci. Philadelphia 6: 177-182. (Tropidonotus rhombifer, new species, p. 177). Schmidt KP, Davis DD (1941). Field Book of Snakes of the United States and Canada. New York: G.P. Putnam's Sons. 365 pp. (Natrix rhombifera rhombifera, pp. 217–218, Figure 71 + Plate 23, Bottom, on p. 343). Wright AH, Wright AA (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock. 1,105 pp. (in 2 volumes). (Natrix rhombifera rhombifera, pp. 500–504, Figure 147, Map 41.) External links Diamondback Water Snake, Reptiles and Amphibians of Iowa rhombifer Reptiles of Mexico Reptiles of the United States Extant Cenozoic first appearances Reptiles described in 1852 Taxa named by Edward Hallowell (herpetologist)