Sistrurus catenatus edwardsii

Sistrurus catenatus edwardsii
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Viperidae
Subfamily: Crotalinae
Genus: Sistrurus
Species: S. catenatus
Subspecies: S. c. edwardsii
Trinomial name
Sistrurus catenatus edwardsii
(Baird & Girard, 1853)
Synonyms
  • Crotalophorus Edwardsii
    Baird & Girard, 1853
  • C[rotalus]. (Crotalophorus) miliarius var. Edwardsii
    – Jan, 1863
  • Caudisona edwardsii
    – Yarrow, 1875
  • [Sistrurus miliarius] Var. edwardsii – Garman, 1884
  • Crotalophorus catenatus edwardsii – Cope, 1892
  • Sistrurus catenatus edwardsii
    – Stejneger, 1895
  • Sistrurus edwardsii
    – Cockerell, 1896
  • Sistrurus catenatus var. edwardsii – Ditmars, 1907
  • Sistrurus catenatus edwardsi
    – Gloyd, 1955
  • Crotalus (Sistrurus) catenatus edwardsi
    – Hoge, 1966[1]
Common names: desert massasauga,[2] Edward's massasauga,[3] Edward's rattlesnake.[4]

Sistrurus catenatus edwardsii is a subspecies of venomous pitviper [5] endemic to the southwestern United States and northern Mexico. In places its range overlaps that of S. c. tergeminus, and intergrading of the two subspecies is not unknown.

Etymology

The subspecific name, edwardsii, is in honor of Colonel Dr. Lewis A. Edwards (1824-1877), a U.S. Army surgeon,[6] who collected the type specimen.[7]

Description

S. c. edwardsi pair in copula (mating)

This subspecies is more slender and smaller than S. c. tergeminus, reaching a maximum length of 53 centimetres (21 in).[2]

The color pattern consists of a light gray or white base color, with dark gray or gray-brown blotches. They have a distinctive, dark stripe that runs along the side of the head which passes over the eye. Their rattles are significantly higher pitched than those of larger species of rattlesnake, sometimes giving them the nickname buzztail.

Compared to S. c. tergeminus, it is paler in color, and its belly is nearly white. Midbody, it has 23 rows of dorsal scales instead of 25, as well as fewer ventral scales and dorsal blotches.[3]

Geographic range

Found in the United States extreme southeastern Arizona, central and southern New Mexico, western Texas about as far north and east as the Colorado River, in the Rio Grande Valley, in many of the Gulf Coast counties about as far north as Brazoria, and on several barrier islands including North Padre Island, Matagorda Island and San José Island. In addition, isolated populations have been reported in northeastern Mexico.[3][8][9] The type locality is listed as "Tamaulipas ... S. Bank of Rio Grande ... Sonora."[1]

Habitat

Primarily found in rocky, semi-arid and arid areas. According to Conant (1975), it is mostly found in desert grasslands.[2]

Behavior

They are primarily nocturnal, especially during the summer months when it is too hot for them to be active, but they will sometimes be found out sunning themselves.

Feeding

Their diet consists primarily of rodents, lizards and frogs.

Venom

Drop for drop, Massasauga venom is more potent than that of many larger species of rattlesnake, but due to the lower yield (the amount it is capable of delivering in a single bite) its potential for harm is greatly reduced. They are not considered to be deadly, but the venom is a powerful hemotoxin which can cause swelling, necrosis, and severe pain. Medical treatment should be sought immediately for any venomous snake bite. The antivenin CroFab, while not type specific, can be used to treat severe envenomations from Massasauga rattlesnakes.

Conservation status

The Desert Massasauga is listed as a species of concern in Colorado, due to its limited range in the state, and it is protected by Arizona state law. It is listed as a sensitive species by the United States Forest Service.

See also

References

  1. ↑ 1.0 1.1 McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).
  2. ↑ 2.0 2.1 2.2 Conant R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Second Edition. First published in 1958. Houghton Mifflin Company. Boston. 429 pp. 48 plates. ISBN 0-395-19979-4 (hc), ISBN 0-395-19977-8 (pb).
  3. ↑ 3.0 3.1 3.2 Wright AH, Wright AA. 1957. Handbook of Snakes of the United States and Canada. Comstock Publishing Associates. Ithaca and London. (7th printing, 1985). 1105 pp. ISBN 0-8014-0463-0.
  4. ↑ Ditmars RL. 1933. Reptiles of the World. Revised Edition. The MacMillan Company. 329 pp. 89 plates.
  5. ↑ "Sistrurus catenatus edwardsii". Integrated Taxonomic Information System. Retrieved 31 January 2007.
  6. ↑ Beolens, Bo; Watkins, Michael; Grayson; Michael. 2011. The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN 978-1-4214-0135-5. (Sistrurus catenatus edwardsii, p. 81).
  7. ↑ Baird & Girard. 1853.
  8. ↑ Klauber LM. 1997. Rattlesnakes: Their Habitats, Life Histories, and Influence on Mankind. Second Edition. First published in 1956, 1972. University of California Press, Berkeley. ISBN 0-520-21056-5.
  9. ↑ Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. ISBN 0-8014-4141-2.

Further reading

  • Baird, S.F. and C.F. Girard. 1853. Catalogue of North American Reptiles in the Museum of the Smithsonian Institution, Part I.—Serpents. Smithsonian Institution. Washington, District of Columbia. xvi + 172 pp. (Crotalophorus edwardsii, p. 15.)
  • Mackessy SP. 2005. Desert Massasauga Rattlesnake (Sistrurus catenatus edwardsii): A Technical Conservation Assessment. USDA Forest Service. PDF at USDA Species Conservation Project. Accessed 31 January 2007.
  • Yarrow, H.C. 1875. Chapter IV. Report upon the Collections of Batrachians and Reptiles made in Portions of Nevada, Utah, Colorado, New Mexico, and Arizona, during the Years 1871, 1872, 1873, and 1874. pp. 511-584. IN Report upon Geographical and Geological Explorations and Surveys West of the One Hundredth Meridian in Charge of First Lieut. Geo. M. Wheeler, Corps of Engineers, U.S. Army...Vol. V.—Zoology. Secretary of War, U.S. Government. Washington, District of Columbia. 1021 pp. (Caudisona edwardsii, pp. 531-532.)

External links

Wikimedia Commons has media related to Sistrurus catenatus.