Rhabdophis | |
---|---|
Rhabdophis subminiatus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Suborder: | Serpentes |
Family: | Colubridae |
Subfamily: | Natricinae |
Genus: | Rhabdophis Fitzinger, 1843 |
Species | |
30, see text. |
Rhabdophis is a genus of snakes in the subfamily Natricinae of the family Colubridae. Species in the genus Rhabdophis are generally called keelback snakes, and are found primarily in Southeast Asia. The best-known species is Rhabdophis tigrinus; few other species have been studied in detail.
Colubrid snakes are often thought of as completely harmless, but there are a handful of notable exceptions, including some species of Rhabdophis. Bites from both Rhabdophis tigrinus and Rhabdophis subminiatus have caused cases of severe envenomation. [1] [2] [3] [4] There are several reports of fatal bites from R. tigrinus. [5] [6] Between 1971 and 2020, 5 of 43 R. tigrinus bites in Japan were fatal, [7] all of which occurred in cases not treated with antivenom. Antivenom is manufactured by the Japan Snake Institute [8] and is an effective treatment for R. tigrinus bites, [9] [10] but is an unapproved drug. The venom is highly hemorrhagic. [11] [12]
While the term "poisonous snake" is often incorrectly used for a wide variety of venomous snakes, some species of Rhabdophis are in fact poisonous as well as venomous. Many species of Rhabdophis have specialized nuchal glands on the back of the neck [13] that are used to store cardiotonic steroids (bufadienolides) sequestered from their diet, [14] mostly from toads but also from firefly larvae. [15] Rhabdophis are resistant to the toxic effects of these chemicals. [16] This is different from their venom, which is produced in oral glands and is not known to contain bufadienolides or other sequestered toxins. Female Rhabdophis tigrinus can pass sequestered chemicals to their offspring, both by deposition in egg yolk and by transfer across the egg membranes within the oviduct, late in gestation. [17]
In 2018, Balanophis ceylonensis and three of the four species in the genus Macropisthodon were reassigned to Rhabdophis on the basis of three genes indicating a common ancestor for all species possessing nuchal glands. [18] At least two species, “R”. conspicillatus and “R”. chrysargos, are more distantly related and might be assigned to other genera in the future. The same analysis suggested that Rhabdophis might contain several undescribed species.
These species are recognized as being valid: [19]
Nota bene : A binomial authority in parentheses indicates that the species was originally described in a genus other than Rhabdophis.
The king cobra is a species complex of snakes endemic to Asia. With an average of 3.18 to 4 m and a record length of 5.85 m (19.2 ft), it is the world's longest venomous snake and among the heaviest. Under the genus Ophiophagus, it is not phylogenetically a true cobra despite its common name and some resemblance. Spanning from the Indian Subcontinent through Southeastern Asia to Southern China, the king cobra is widely distributed albeit not commonly seen.
Antivenom, also known as antivenin, venom antiserum, and antivenom immunoglobulin, is a specific treatment for envenomation. It is composed of antibodies and used to treat certain venomous bites and stings. Antivenoms are recommended only if there is significant toxicity or a high risk of toxicity. The specific antivenom needed depends on the species involved. It is given by injection.
Elapidae is a family of snakes characterized by their permanently erect fangs at the front of the mouth. Most elapids are venomous, with the exception of the genus Emydocephalus. Many members of this family exhibit a threat display of rearing upwards while spreading out a neck flap. Elapids are endemic to tropical and subtropical regions around the world, with terrestrial forms in Asia, Australia, Africa, and the Americas and marine forms in the Pacific and Indian Oceans. Members of the family have a wide range of sizes, from the 18 cm (7.1 in) white-lipped snake to the 5.85 m king cobra. Most species have neurotoxic venom that is channeled by their hollow fangs, and some may contain other toxic components in varying proportions. The family includes 55 genera with around 360 species and over 170 subspecies.
Mambas are fast-moving, highly venomous snakes of the genus Dendroaspis in the family Elapidae. Four extant species are recognised currently; three of those four species are essentially arboreal and green in colour, whereas the black mamba, Dendroaspis polylepis, is largely terrestrial and generally brown or grey in colour. All are native to various regions in sub-Saharan Africa and all are feared throughout their ranges, especially the black mamba. In Africa there are many legends and stories about mambas.
A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may occur. This may result in redness, swelling, and severe pain at the area, which may take up to an hour to appear. Vomiting, blurred vision, tingling of the limbs, and sweating may result. Most bites are on the hands, arms, or legs. Fear following a bite is common with symptoms of a racing heart and feeling faint. The venom may cause bleeding, kidney failure, a severe allergic reaction, tissue death around the bite, or breathing problems. Bites may result in the loss of a limb or other chronic problems or even death.
Snake venom is a highly toxic saliva containing zootoxins that facilitates in the immobilization and digestion of prey. This also provides defense against threats. Snake venom is usually injected by unique fangs during a bite, though some species are also able to spit venom.
The boomslang is a highly venomous snake in the family Colubridae. The species is native to Sub-Saharan Africa.
The black mamba is a species of highly venomous snake belonging to the family Elapidae. It is native to parts of sub-Saharan Africa. First formally described by Albert Günther in 1864, it is the second-longest venomous snake after the king cobra; mature specimens generally exceed 2 m and commonly grow to 3 m (9.8 ft). Specimens of 4.3 to 4.5 m have been reported. Its skin colour varies from grey to dark brown. Juvenile black mambas tend to be paler than adults and darken with age. Despite the common name, the skin of a black mamba is not black; the color name describes rather the inside of its mouth, which it displays when feeling threatened.
The Indian cobra, also known commonly as the spectacled cobra, Asian cobra, or binocellate cobra, is a species of cobra, a venomous snake in the family Elapidae. The species is native to the Indian subcontinent, and is a member of the "big four" species that are responsible for the most snakebite cases in India.
Rhabdophis subminiatus, commonly called the red-necked keelback or red-necked keelback snake, is a species of venomous snake in the subfamily Natricinae of the family Colubridae. The species is endemic to Asia. Unusual for snakes, it is also poisonous.
Gloydius blomhoffii, commonly known as the mamushi, Japanese moccasin, Japanese pit viper, Qichun snake, Salmusa or Japanese mamushi, is a pit viper species found in Japan. It was once considered to have 4 subspecies, but it is now considered monotypic.
The Natricinae are a subfamily of colubroid snakes, sometimes referred to as a family (Natricidae). The subfamily comprises 36 genera. Members include many very common snake species, such as the European grass snakes, and the North American water snakes and garter snakes. Some Old World members of the subfamily are known as keelbacks, because their dorsal scales exhibit strong keeling.
A dry bite is a bite by a venomous animal in which no venom is released. Dry snake bites are called "venomous snake bite without envenoming". A dry bite from a snake can still be painful, and be accompanied by bleeding, inflammation, swelling and/or erythema. It may also lead to infection, including tetanus.
Rhabdophis tigrinus, also known commonly as the tiger keelback, yamakagashi, or kkotbaem, is a species of venomous snake in the subfamily Natricinae of the family Colubridae. The species is native to East Asia and Southeast Asia. Many sources, though not ITIS, recognize one subspecies, Rhabdophis tigrinus formosanus of Taiwan.
Tachymenis is a genus of venomous snakes belonging to the family Colubridae. Species in the genus Tachymenis are commonly known as slender snakes or short-tailed snakes and are primarily found in southern South America. Tachymenis are rear-fanged (opisthoglyphous) and are capable of producing a medically significant bite, with at least one species, T. peruviana, responsible for human fatalities.
Most snakebites are caused by non-venomous snakes. Of the roughly 3,700 known species of snake found worldwide, only 15% are considered dangerous to humans. Snakes are found on every continent except Antarctica. There are two major families of venomous snakes, Elapidae and Viperidae. 325 species in 61 genera are recognized in the family Elapidae and 224 species in 22 genera are recognized in the family Viperidae, In addition, the most diverse and widely distributed snake family, the colubrids, has approximately 700 venomous species, but only five genera—boomslangs, twig snakes, keelback snakes, green snakes, and slender snakes—have caused human fatalities.
Rhabdophis ceylonensis is endemic to the island of Sri Lanka. The species is commonly known as the Sri Lanka blossom krait, the Sri Lanka keelback, and මල් කරවලා or නිහලුවා (nihaluwa) in Sinhala. It is a moderately venomous snake.
Rhabdophis swinhonis is a species of snake in the subfamily Natricinae of the family Colubridae. The species is endemic to Taiwan. It is also known commonly as the Taiwan keelback and Swinhoe's grass snake.
A toxungen comprises a secretion or other bodily fluid containing one or more biological toxins that is transferred by one animal to the external surface of another animal via a physical delivery mechanism with or without direct contact between the secreting animal and the victim. Toxungens can be delivered through spitting, spraying, or smearing. As one of three categories of biological toxins, toxungens can be distinguished from poisons, which are passively transferred via ingestion, inhalation, or absorption across the skin, and venoms, which are delivered through a wound generated by direct contact in the form of a bite, sting, or other such action. Toxungen use offers the evolutionary advantage of delivering toxins into the target's tissues without the need for physical contact. Animals that deploy toxungens are referred to as toxungenous.