The eastern diamondback rattlesnake (''Crotalus adamanteus'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

pit viper The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . or pit adders, are a subfamily (biology), subfamily of Viperidae, vipers found in Asia and the ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Viperidae Vipers are snakes in the family Viperidae, found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, New Zealand, Ireland, and various other isolated islands. They are venomous snake, venomous and have long (relat ...

. The species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

Southeastern United States The Southeastern United States, also known as the American Southeast or simply the Southeast, is a geographical List of regions in the United States, region of the United States located in the eastern portion of the Southern United States and t ...

. It is the largest

rattlesnake Rattlesnakes are venomous snakes that form the genus, genera ''Crotalus'' and ''Sistrurus'' of the subfamily Crotalinae (the pit vipers). All rattlesnakes are vipers. Rattlesnakes are predators that live in a wide array of habitats, hunting sm ...

species and one of the heaviest

venomous snake ''Venomous snakes'' are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow ...

s in the

Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...

. No subspecies are recognized.

Description

The eastern diamondback rattlesnake is the largest rattlesnake species and is one of the heaviest known species of venomous snake, with one specimen shot in 1946 measuring in length and weighing . However, other venomous snakes may rival this species in weight such as the much longer but more slender

king cobra The king cobra (''Ophiophagus hannah'') is a species complex of snakes Endemism, endemic to Asia. With an average of and a record length of , it is the world's longest venomous snake and among the heaviest. Under the genus ''Ophiophagus'', i ...

and the shorter but even bulkier Gaboon viper. Maximum reported lengths for the eastern diamondback rattlesnake are and . However, the stated maximum sizes have been called into question due to a lack of voucher specimens. Males are typically larger than females, which is rare among snakes (females are usually larger than males). Specimens over are rare, but well documented. Klauber (1998) included a letter he received from E. Ross Allen in 1953, in which Allen explains how for years he offered a reward of $100, and later $200, for an specimen, dead or alive. The reward was never claimed. He did receive a number of range specimens and some skins, but said such skins can be taken from specimens as short as . A specimen was caught and killed outside a neighborhood in

St. Augustine, Florida St. Augustine ( ; ) is a city in and the county seat of St. Johns County, Florida, United States. Located 40 miles (64 km) south of downtown Jacksonville, the city is on the Atlantic coast of northeastern Florida. Founded in 1565 by Spani ...

in September 2009. The average size is much less. Specimens are rarely found over 6 feet in length. Lengths of ,United States Navy (1991). ''Poisonous Snakes of the World''. New York: US Government / Dover Publications Inc. 204 pp. . and are given.Conant R (1975). ''A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition''. First published in 1958. Boston: Houghton Mifflin Company. xviii + 429 pp. + 48 plates. (hc), (pb). One study found an average length of based on 31 males and 43 females. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates, a division of Cornell University Press. (7th printing, 1985). 1,105 pp. . The average body mass is roughly . The average weight of 9 laboratory-kept specimens was , with a range of . Few specimens can exceed , although exceptional specimens can weigh or more. The scalation includes 25–31 (usually 29) rows of

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

at midbody, 165–176/170–187

ventral scales In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that cont ...

in males/females and 27–33/20–26

subcaudal scales In snakes, the subcaudal scales are the enlarged plates on the underside of the tail. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Comstock Publishing Associates, a Division of Cornell University Press. (7t ...

in males/females, respectively. On the head, the

rostral scale The rostral scale, or rostral, in snakes and other scaled reptiles is the median plate on the tip of the snout that borders the mouth opening. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: ...

is higher than it is wide and contacts two internasal scales. There are 10–21 scales in the internasal- prefrontal region and 5–11 (usually 7–8) intersupraocular scales. Usually, there are two loreal scales between preoculars and the postnasal. There are 12–17 (usually 14–15)

supralabial scales In reptiles, the supralabial scales, also called upper-labials, are those scales that border the mouth opening along the upper jaw. They do not include the median scaleWright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates ( ...

, the first of which is in broad contact with the prenasal, and 15–21 (usually 17–18)

sublabial scales In reptiles, the sublabial scales, also called lower-labials or infralabials, are those scales that border the mouth opening along the lower jaw. They do not include the median scaleWright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publis ...

. The color pattern consists of a brownish, brownish-yellow, brownish-gray or olive ground color, overlaid with a series of 24–35 dark brown to black diamonds with slightly lighter centers. Each of these diamond-shaped blotches is outlined with a row of cream or yellowish scales. Posteriorly, the diamond shapes become more like crossbands and are followed by 5–10 bands around the tail. The belly is a yellowish or cream-colored, with diffused, dark mottling along the sides. The head has a dark postocular stripe that extends from behind the eye backwards and downwards to the lip; the back of the stripe touches the angle of the mouth. Anteriorly and posteriorly, the postocular stripe is bordered by distinct white or yellow stripes. The rattle at the end of their tail is made of hard, loosely attached, hollow segments which break off frequently and are completely replaced when the snake sheds.

Common names

Other common names for this snake species include eastern diamond-backed rattlesnake, eastern diamondback, diamond rattlesnake, diamond-back rattlesnake, common rattlesnake, diamond-back, diamond(-patch) rattler, eastern diamond-back (rattlesnake), eastern diamond rattlesnake, Florida diamond-back (rattlesnake), Florida rattlesnake, lozenge-spotted rattlesnake, rattler, rattlesnake, southeastern diamond-backed rattlesnake, southeastern diamond-backed rattler, southern woodland rattler, timber rattler, water rattle, water rattlesnake, and diamondback rattlesnake.

Geographic range

The eastern diamondback rattlesnake is found in the

from southeastern

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

, south along the coastal plain through peninsular

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

to the

Florida Keys The Florida Keys are a coral island, coral cay archipelago off the southern coast of Florida, forming the southernmost part of the continental United States. They begin at the southeastern coast of the Florida peninsula, about south of Miami a ...

, and west along the Gulf Coast through southern

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

and

Mississippi Mississippi ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the s ...

to southeastern

Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...

. The original description for the species does not include a type locality, although Schmidt (1953) proposed it be restricted to "

Charleston, South Carolina Charleston is the List of municipalities in South Carolina, most populous city in the U.S. state of South Carolina. The city lies just south of the geographical midpoint of South Carolina's coastline on Charleston Harbor, an inlet of the Atla ...

" (USA). McDiarmid RW, Campbell JA, Touré T (1999). ''Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1''. Washington, District of Columbia. Herpetologists' League. 511 pp. (series). (volume).

Conservation status

This snake species is classified as Least Concern on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

(v3.1, 2001). Species are listed as such owing to their wide distribution or presumed large population, or because they are unlikely to be declining fast enough to qualify for listing in a more threatened category. The population trend was down when assessed in 2007. In North Carolina, the eastern diamondback rattlesnake is protected by state law and considered endangered within the state. It is likely extirpated in

, having last been observed there in 1995. In fact some scientists and conservationists believe it may even be extirpated in North Carolina, having last been observed there in the early 1990s. This species is currently under review for being added to the Endangered Species List by the

United States Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is a List of federal agencies in the United States, U.S. federal government agency within the United States Department of the Interior which oversees the management of fish, wildlife, ...

owing to its recent decline, and the current population represents only 3% of the historical population. Eastern diamondback rattlesnakes (''Crotalus adamanteus'', EDB) have limited ability to adapt to habitat loss and fragmentation due to the species' slow life history, high habitat specificity, and minimal dispersal ability. Threats to eastern diamondback rattlesnake include habitat loss, killing by humans, and highway mortality. Rattlesnake roundups are another threat to this species, as they are removed from the wild and killed for exhibition and entertainment. One common method of capture at these events involves pouring gasoline down a rattlesnake's supposed burrow, a practice which is harmful to both the snake and its environment. A study was conducted in South Carolina that showed positive results in translocating species to save them due to their inability to adapt to habitat loss.

Habitat

The eastern diamondback rattlesnake inhabits upland dry pine forest, pine and palmetto flatwoods,

sandhill A sandhill is a type of ecological community or xeric wildfire-maintained ecosystem. It is not the same as a sand dune. It features very short fire return intervals, one to five years. Without fire, sandhills undergo ecological succession and b ...

s and coastal maritime hammocks,

longleaf pine The longleaf pine (''Pinus palustris'') is a pine species native to the Southeastern United States, found along the coastal plain from East Texas to southern Virginia, extending into northern and central Florida. In this area it is also known as ...

/ turkey oak habitats, grass-sedge marshes and swamp forest, cypress swamps, mesic hammocks, sandy mixed woodlands, xeric hammocks, and

salt marsh A salt marsh, saltmarsh or salting, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. I ...

es, as well as wet prairies during dry periods. In many areas, it seems to use burrows made by

gopher Pocket gophers, commonly referred to simply as gophers, are burrowing rodents of the family Geomyidae. The roughly 41 speciesSearch results for "Geomyidae" on thASM Mammal Diversity Database are all endemic to North and Central America. They ar ...

s and gopher tortoises during the summer and winter.

Behavior

The eastern diamondback rattlesnake frequently shelters by tunneling in gopher and tortoise burrows, emerging in the early morning or afternoon to bask.Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . Some research shows that these snakes spend less time underground during their active seasons. Like most rattlesnakes, this species is terrestrial and not adept at climbing. However, it has on occasion been reported in bushes and trees, apparently in search of prey. Even large specimens have been spotted as high as above the ground. It is also known to be an excellent swimmer. Specimens have often been spotted crossing stretches of water between

barrier island Barrier islands are a Coast#Landforms, coastal landform, a type of dune, dune system and sand island, where an area of sand has been formed by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of an ...

s and the mainland off the

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

coast, in the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

and in the Florida Keys, sometimes miles from land. Individual disposition varies, with some allowing close approach while remaining silent, and others starting to rattle at a distance of . The rattle is well developed and can be heard from relatively far away. When threatened, it raises the anterior half of the body off the ground in an S-shaped coil, and can strike to a distance of at least a third of its body length.Ashton RE Jr, Sawyer-Ashton P (1981). ''Handbooks of Reptiles and Amphibians of Florida, Part 1, The Snakes''. Miami, Florida: Windward Publishing Inc. 176 pp. LCCCN 81-51066. . Many will stand their ground and may strike repeatedly, but if given the opportunity, they will usually retreat while facing the intruder and moving backwards towards shelter, after which they disappear. One popular myth is that the eastern diamondback rattlesnake must rattle before striking. To the contrary, it is quite capable of striking while remaining completely silent.Eastern Diamondback Rattlesnake
a
Florida Museum of Natural History
Accessed 2 July 2008. Hawks, eagles, and other snakes have been known to prey upon young and adolescent specimens of the eastern diamondback rattlesnake.

Feeding

The eastern diamondback rattlesnake forages actively or lies in ambush for small mammals, especially rabbits and rice rats (''

Oryzomys ''Oryzomys'' is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat (''O. palustris'') of the United States and ...

''). The diet also includes birds. Eastern Diamondback rattlesnakes may sit and wait in a coiled position for up to a week while waiting for prey. Prey is struck and released, after which the snake follows the scent trail left by the dying prey. Because of their large size, adults have no problem eating prey as large as fully grown cottontail rabbits. As the juveniles are capable of swallowing adult mice, they do not often resort to eating slimmer prey, such as lizards. In fact, eastern cottontails and marsh rabbits (''

Sylvilagus Cottontail rabbits are in the ''Sylvilagus'' genus, which is in the family Leporidae. They are found in the Americas. Most ''Sylvilagus'' species have stub tails with white undersides that show when they retreat, giving them their characteris ...

'') form the bulk of the diet in most parts of Florida. Squirrels, rats, and mice are also eaten, along with birds such as

towhee A towhee is any one of a number of species of birds in the genus ''Pipilo'' or ''Melozone'' within the family Passerellidae (which also includes American sparrows and juncos). Towhees typically have longer tails than other Passerellidae. Most sp ...

s and

bobwhite quail The northern bobwhite (''Colinus virginianus''), also known as the Virginia quail or (in its home range) bobwhite quail, is a ground-dwelling bird native to Canada, the United States, Mexico, and Cuba, with introduced populations elsewhere in th ...

. Other prey that have been reported include a

king rail The king rail (''Rallus elegans'') is a waterbird, the largest North American Rallidae, rail. Description Distinct features are a long beak, bill with a slight downward curve, with adults being brown on the back and rusty-brown on the face and ...

, a young

wild turkey The wild turkey (''Meleagris gallopavo'') is an upland game bird native to North America, one of two extant species of Turkey (bird), turkey and the heaviest member of the order Galliformes. It is the ancestor to the domestic turkey (''M. g. dom ...

, and a mother woodpecker along with four of her eggs. It also eats large insects.

Reproduction

Rattlesnakes, including the eastern diamondback, are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparity, oviparous and live-bearing viviparity, viviparous reproduction. Ovoviviparous animals possess embryos that develo ...

. Gestation lasts six or seven months and broods average about a dozen young. However, the young only stay with the mother 10–20 days before they set off on their own to hunt and find cover. Their life history is considered to be slow since they breed on intervals of 2–4 years. Females give birth to between 4 and 28 young at a time, usually between July and early October. Neonates are in length Behler JL, King FW (1979). ''The Audubon Society Field Guide to North American Reptiles and Amphibians''. New York: Alfred A. Knopf. 743 pp. . . and are similar in appearance to the adults, except for having only a small button instead of a rattle on the tip of their tails.

Captivity

The eastern diamondback can live beyond 20 years, but life expectancy in the wild is now typically shorter because of hunting and human expansion. Crotalus adamanteus IMG 5058

Adult wild-caught specimens are often difficult to maintain in captivity, but captive-born individuals do quite well and feed readily on killed laboratory rodents. The eastern diamondback requires a dry and well-ventilated cage with a hide-box, maintained at a temperature of for normal activity.

Venom

The eastern diamondback rattlesnake has the reputation of being the most dangerous

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. While not usually aggressive, it is large and powerful.

Wright Wright is an occupational surname originating in England and Scotland. The term 'Wright' comes from the circa 700 AD Old English word 'wryhta' or 'wyrhta', meaning worker or shaper of wood. Later it became any occupational worker (for example, a ...

and

mentioned a mortality rate of 30%, but other studies show a mortality rate of 10–20% (untreated). The eastern diamondback rattlesnake is a major leader of fatal snakebites within its geographical range. In proportion to its length, it has the longest fangs of any rattlesnake species, with calculations leading one to expect an specimen would have fangs with a total length of over . For comparison, a specimen had fangs measuring in length. It has a very high venom yield, an average of 400–450 mg, with a maximum of 858–1,000 mg.Norris R (2004). "Venom Poisoning in North American Reptiles". ''In'': Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publishing Associates. 870 pp. 1,500 plates. . Brown gives an average venom yield of 410 mg (dried venom), along with values of 1.3–2.4 mg/kg IV, 1.7–3.0 mg/kg IP and 14.5–10 mg/kg SC for toxicity.Brown JH (1973). ''Toxicology and Pharmacology of Venoms from Poisonous Snakes''. Springfield, Illinois: Charles C. Thomas. 184 pp. . . The estimated human lethal dose is 100–150 mg. Eastern diamondback rattlesnake venom is estimated to contain over 100 different toxins. This venom is one of the most studied snake venoms with around 40 toxins characterized. The venom contains a

thrombin Prothrombin (coagulation factor II) is encoded in the human by the F2-gene. It is proteolytically cleaved during the clotting process by the prothrombinase enzyme complex to form thrombin. Thrombin (Factor IIa) (, fibrose, thrombase, throm ...

-like

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

, "crotalase", capable of clotting

fibrinogen Fibrinogen (coagulation factor I) is a glycoprotein protein complex, complex, produced in the liver, that circulates in the blood of all vertebrates. During tissue and vascular injury, it is converted Enzyme, enzymatically by thrombin to fibrin ...

, leading to the secondary activation of

plasminogen Plasmin is an important enzyme () present in blood that degrades many blood plasma proteins, including fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein (in the zymogen form of plasminogen) is enco ...

from

endothelial The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the res ...

cells. Although the venom does not activate

platelet Platelets or thrombocytes () are a part of blood whose function (along with the coagulation#Coagulation factors, coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a thrombus, blood clot. Platelets have no ...

s, the production of

fibrin Fibrin (also called Factor Ia) is a fibrous protein, fibrous, non-globular protein involved in the Coagulation, clotting of blood. It is formed by the action of the protease thrombin on fibrinogen, which causes it to polymerization, polymerize. ...

strands can result in a reduced platelet count, as well as the

hemolysis Hemolysis or haemolysis (), also known by #Nomenclature, several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may ...

red blood cell Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cel ...

s (see article on

MAHA Maha and MAHA may refer to: * Maha (name), an Arabic feminine given name * ''Maha'' (film), an Indian Tamil-language thriller film * MaHa, Nepali comedy duo, Madan Krishna Shrestha and Hari Bansha Acharya * Make America Healthy Again (MAHA), th ...

). Even with this defibrination, however, clinically significant bleeding is uncommon. Nevertheless, the venom does exhibit high hemorrhagic activity. It also contains a low-molecular-weight basic

peptide Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty am ...

that impedes neuromuscular transmission and can in theory lead to

cardiac failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF typically pre ...

. This peptide is similar to crotamine from '' C. durrisus terrificus'', and makes up 2–8% of the protein found in the venom. In general, the venom can be described as highly

necrotizing Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who is ...

, mildly

proteolytic Proteolysis is the breakdown of proteins into smaller polypeptides or amino acids. Protein degradation is a major regulatory mechanism of gene expression and contributes substantially to shaping mammalian proteomes. Uncatalysed, the hydrolysis o ...

and containing a large

phosphodiesterase A phosphodiesterase (PDE) is an enzyme that breaks a phosphodiester bond. Usually, ''phosphodiesterase'' refers to cyclic nucleotide phosphodiesterases, which have great clinical significance and are described below. However, there are many oth ...

fraction. It stimulates the release of

bradykinin Bradykinin (BK) (from Greek ''brady-'' 'slow' + ''-kinin'', ''kīn(eîn)'' 'to move') is a peptide that promotes inflammation. It causes arterioles to dilate (enlarge) via the release of prostacyclin, nitric oxide, and endothelium-derived hyperpo ...

that can result in severe pain, as well as profound, transient

hypotension Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...

. Klauber described one case in which the symptoms included instant pain "like two hot hypodermic needles", spontaneous bleeding from the bite site, intense internal pain, bleeding from the mouth, hypotension, a weak pulse, swelling and discoloration of the affected limb, and associated severe pain. The symptoms were further described as strongly hemolytic and hemorrhagic.

CroFab Crotalidae polyvalent immune Fab (ovine), sold under the brandname CroFab, is a snake antivenin, indicated for North American crotalid (rattlesnake, copperhead and cottonmouth/water moccasin) snake envenomation. CroFab is composed of several ...

, Anavip, and

Wyeth Wyeth Pharmaceuticals Inc. was a pharmaceutical company until it was purchased by Pfizer in 2009. The company was founded in Philadelphia, Pennsylvania, in 1860 as John Wyeth and Brother. Its headquarters moved to Collegeville, Pennsylvania, a ...

's ACP are effective antivenins against bites from this species, although massive doses may be needed to manage severe cases of envenomation. Generally, ACP is very effective at countering the defibrination syndrome that is often seen, but may do little for low platelet counts. Wyeth's ACP is no longer being manufactured.