The Crotalinae, commonly known as pit vipers, or pit adders, are a subfamily of vipers found in Asia and the Americas. Like all other vipers, they are venomous. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on both sides of the head. Currently, 23 genera and 155 species are recognized: These are also the only viperids found in the Americas. The groups of snakes represented here include rattlesnakes, lanceheads, and Asian pit vipers. The type genus for this subfamily is Crotalus, of which the type species is the timber rattlesnake, C. horridus.
Agkistrodon is a genus of pit vipers commonly known as American moccasins. The genus is endemic to North America, ranging from the Southern United States to northern Costa Rica. Eight species are currently recognized, all of them monotypic and closely related. Common names include: cottonmouths, copperheads, and cantils.
Trimeresurus is a genus of pit vipers found in Asia from the Indian Subcontinent throughout Southeast Asia, China, and the Pacific Islands. Currently 44 species are recognized. Common names include Asian palm pit vipers, Asian lanceheads, and green pit vipers.
Trimeresurus albolabris, the white-lipped pit viper or white-lipped tree viper, is a venomous pit viper species endemic to Southeast Asia.
Tropidolaemus is a genus of venomous pit vipers in the subfamily Crotalinae of the family Viperidae. Member species are native to southern India and Southeast Asia. Five species are recognised as being valid, and none of these species has subspecies.
Protobothrops mangshanensis, commonly known as the Mangshan pit viper, Mangshan pitviper, Mt. Mang pitviper, or Mang Mountain pitviper, is a venomous pit viper species endemic to Hunan and Guangdong provinces in China. No subspecies are currently recognized. This is a nocturnal pit viper that is also known as the ''Mangshan iron-head snake'', ''Chinese pit viper'', and the ''Ironhead viper''. They eat frogs, birds, insects, and small mammals. They have a white tail tip that they wiggle to mimic a grub so that prey comes into striking range—a behaviour known as caudal luring. The venom causes blood clotting and corrodes muscle tissue and can be fatal to humans if not treated. Unusually for vipers, P. mangshanensis is oviparous with the female laying clutches of 13–21 eggs which she will guard until they hatch.
The Florida cottonmouth is a species of venomous snake, a pit viper in the subfamily Crotalinae of the family Viperidae. The species is endemic to the United States, where it occurs in southern Georgia and the Florida peninsula in nearly every type of wetlands in the region, including brackish water and offshore islands. However, it is not entirely dependent on water and is occasionally encountered as far as a mile from surface water. Agkistrodon conanti venom is very hemolytic and known to cause relatively extensive necrosis compared to many snake venoms, and can sometimes be lethal with a 17% mortality rate. It is often confused with harmless watersnakes (Nerodia) and other semi-aquatic species with which it shares its habitat.
Gloydius saxatilis is a venomous pitviper species endemic to Russia, China and the Korean Peninsula. No subspecies are currently recognized.
Gloydius halys is a pit viper species found within a wide range that stretches across Asia, from Russia, east of the Urals, eastwards through China. Five subspecies are currently recognized, including the nominotypical form described here.
Craspedocephalus brongersmai, also known commonly as Brongersma's pit viper, is a species of venomous snake in the subfamily Crotalinae of the family Viperidae. The species is native to islands off the west coast of Sumatra, Indonesia. No subspecies are currently recognized.
Agkistrodon howardgloydi is a species of venomous snake, a pit viper in the subfamily Crotalinae of the family Viperidae. The species is endemic to Central America. It is most commonly called castellana, but it has also been called the southern cantil, Gloyd's moccasin, and a number of other colloquial names. It is a rare species with a relatively small geographic distribution in the tropical dry forest on the Pacific coast of Honduras, Nicaragua, and extreme northwest Costa Rica. A. howardgloydi is a stout, medium-sized snake with a maximum total length of 96 cm (38 in). It is a viviparous species, with females giving birth in the rainy season from May to August. No clinical reports on envenomation had been published, but laboratory texts and analysis indicate the venom is highly toxic and similar to its close relative Agkistrodon bilineatus, and potentially lethal.
Gloydius intermedius, or Central Asian pit viper, is a venomous species of pitviper endemic to northern Asia. Three subspecies are currently recognized, including the nominate subspecies described here.
Gloydius monticola is a venomous pitviper species endemic to southern China. A small and darkly colored snake with no visible color pattern, it is found high in the mountains of northern Yunnan province. No subspecies are currently recognized.
Gloydius shedaoensis is a venomous pitviper species found only on Shedao Island in China. Although very small, this island is home to an extraordinarily large population of these snakes. No subspecies are currently recognized.
Gloydius strauchi is a species of venomous pit viper in the subfamily Crotalinae of the family Viperidae. The species is native to western China. It is a small snake with a pattern of four longitudinal stripes, although some older specimens may be a uniform black. G. strauchi may be distinguished from G. monticola by its higher midbody dorsal scale count. This species jointly holds the altitude record for pitvipers together with Crotalus triseriatus of Mexico, both being found even above the tree line at over 4,000 m (13,000 ft). No subspecies were recognized as being valid, until a recent publication re-evaluated the taxonomic statuses of populations of G. strauchi and described the eastern Tibetan populations as a new species.
Bothrops jonathani, known commonly as Jonathan's lancehead or the Cochabamba lancehead, is a species of venomous snake, a pit viper in the family Viperidae. The species is endemic to South America.
Bothrocophias lojanus, also known commonly as the Lojan lancehead in English, and macanchi or macaucho in Spanish, is a species of venomous pit viper in the subfamily Crotalinae of the family Viperidae. The species is native to northwestern South America.
Gloydius tsushimaensis, or the Tsushima Island pitviper, is a species of venomous snake in the family Viperidae. The species is endemic to Tsushima Island in Japan.
Gloydius lateralis is a species of venomous pit viper found in the Zharu Valley of Jiuzhaigou County, China. The species is active during sunny days in hot and dry areas along roadsides. The Zharu Valley is the sole known location of G. lateralis. This snake is assumed to eat small mammals like mice, based on the fur remnants found within its droppings. This species lineage is a sister taxon to G. swild, being morphologically and phylogenetically similar.
Gloydius chambensis, the Chamba pitviper, is a species of venomous snake belonging to the family Viperidae and the subfamily Crotalinae, the pit vipers. It was described in 2022 from the Chamba District of Himachal Pradesh in the southern Himalayas of northern India. It was identified as a separate species from Gloydius himalayanus by genetic differences and by differences in the counts of scales in some tracts.
