Common names: western massasauga, ground rattlesnake, Gulf coast massasauga, more.

Sistrurus catenatus tergeminus is a venomous

Venomous snake

"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 pitviper

Crotalinae

The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...

 subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 found in the southwestern plains of the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. In some areas its range overlaps that of another subspecies, S. c. edwardsii

Sistrurus catenatus edwardsii

Sistrurus catenatus edwardsii is a venomous snake pitviper subspecies found in 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....

, and intergrading of the two is not unknown.

Description

Adults range in size from 35 cm to 91 cm. The standard length for 43 male and 63 female adult specimens was 68 cm. Conant (1975) mentions an average length of 46-66 cm, with a maximum of 88.3 cm.

The color pattern is similar to that of S. c. catenatus

Sistrurus catenatus

Sistrurus catenatus is a venomous pitviper species found primarily in the United States. Three subspecies are currently recognized, including the nominate subspecies described here.-Description:...

, but paler: the dark brown blotches contrast strongly with the tan-gray or light gray ground color. The venter (belly) is light with a few dark markings.

Common names

Western massasauga, ground rattlesnake, Gulf coast massasauga, Edward's massasauga, large ground rattlesnake, pigmy rattlesnake, prairie rattlesnake, Say's false rattlesnake, Sonora ground rattlesnake, Texas massasauga, three-spotted shield rattler, triple-spotted rattlesnake.

Geographic range

Found in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 in the southwestern plains from extreme southeastern Nebraska

Nebraska

Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....

 and northwestern Missouri

Missouri

Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...

, southwest through east-central Kansas

Kansas

Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...

 and west-central Oklahoma

Oklahoma

Oklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...

 into northern and central Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 about as far southwest as the Colorado River

Colorado River (Texas)

The Colorado River is a river that runs through the U.S. state of Texas; it should not be confused with the much longer Colorado River which flows from Colorado into the Gulf of California....

. The type locality given is "between the Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 and the Rocky Mountains

Rocky Mountains

The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...

."

Behavior

Primarily found in grassland

Grassland

Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...

 areas, on the edge of open woodland, or on rocky hillsides, and often makes use of the burrows of other animals for shelter. They primarily eat rodent

Rodent

Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

s, but they may also eat lizard

Lizard

Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...

s and frog

Frog

Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...

s. Their rattles are significantly higher pitched than those of larger species of rattlesnake, sometimes giving them the nickname buzztail. They are primarily nocturnal

Nocturnal animal

Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. The common adjective is "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. They are most often found immediately after rain storms.

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. The venom is a powerful hemotoxin

Hemotoxin

Hemotoxins, haemotoxins or hematotoxins are toxins that destroy red blood cells , disrupt blood clotting, and/or cause organ degeneration and generalized tissue damage. The term hemotoxin is to some degree a misnomer since toxins that damage the blood also damage other tissues...

 which can cause swelling, necrosis

Necrosis

Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...

, and severe pain. Despite it's smaller size and less severe bite, envenomation can still be fatal if untreated, and treatment should be sought immediately for any venomous snake

Venomous snake

"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 bite. The antivenin

Antivenin

Antivenom is a biological product used in the treatment of venomous bites or stings. Antivenom is created by milking venom from the desired snake, spider or insect. The venom is then diluted and injected into a horse, sheep or goat...

 CroFab

CroFab

CroFab is the commercial name for a Crotalidae Polyvalent Immune Fab snake antivenom, indicated for minimal or moderate North American Crotalid snake envenomation. It is developed and manufactured by BTG plc , and distributed in the US by Nycomed Inc...

, while not type specific, can be used to treat severe envenomations from Massasauga rattlesnakes.

External links

• Sistrurus catenatus at Herps of Texas. Accessed 1 February 2007.