Philippine cobra | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Suborder: | Serpentes |
Family: | Elapidae |
Genus: | Naja Laurenti, 1768 |
Species: | N. philippinensis |
Binomial name | |
Naja philippinensis | |
Distribution of the Philippine cobra |
The Philippine cobra (Naja philippinensis) also called Philippine spitting cobra or northern Philippine cobra, is a stocky, highly venomous species of spitting cobra native to the northern regions of the Philippines. The Philippine cobra is called ulupong in Tagalog, carasaen in Ilocano.
Naja philippinensis was described by American herpetologist Edward Harrison Taylor in 1922. The generic name naja is a Latinisation of the Sanskrit word nāgá ( नाग ) meaning "cobra". The specific epithet philippinensis is Latin and literally means "from the Philippine Islands". [3]
The Philippine cobra is a stocky snake of medium length with long cervical ribs capable of expanding, so when threatened, a hood can be formed. The average length of this species is 1.0 metre (3.3 ft). [4] The species can grow to lengths of 1.6 metres (5.2 ft) [4] However, subpopulations of the species, particularly specimens from Mindoro Island, are said to attain lengths of 2 metres (6.6 ft), but these are unconfirmed claims. If true, however, 2 m would be very rare and would be considered the absolute maximum for this species. [5] The head is elliptical, depressed, slightly distinct from neck with a short, rounded snout and large nostrils. The eyes are moderate in size with dark brown and round pupils, typical of other cobra species and similar to other elapids in general. It has a fairly stocky build for an elapid, and adult snakes are uniformly light to medium brown, while the juveniles tend to be a darker brown in color. [4] They have 23-27 scale rows around the neck and 21 just above the middle part of the body; 182-193 ventrals, 36-49 subcaudals, and basal pairs are sometimes undivided. [4] [6]
This snake has the ability to spit but seldom does so, often choosing to biting and striking instead when threatened.
There are 23-27 (usually 25) scale rows around neck, 21 (rarely 23) just ahead of mid-body; 182-193 ventrals, 36-49 subcaudals, basal pairs sometimes undivided. [7]
The Philippine cobra occurs mostly in the northern regions of the Philippines. They can be found on the islands of Luzon, Mindoro, Catanduanes, and Masbate. This species likely may occur in other neighboring islands, but this remains unconfirmed. Records from the Calamianes group and Palawan require confirmation. [8]
The Philippine cobra's habitat include low-lying plains and forested regions, [4] along with open fields, grasslands, dense jungle, agricultural fields, and human settlements. This species of cobra is particularly fond of water, so it can be found very close to ponds, rivers, or large puddles of water. [4] [9]
This species feeds predominantly on small mammals, frogs, and even other snakes. [4] Small rodents such as mice and small rats are their preferred prey and make up the majority of their diets. However, they will also eat other sizable snakes, small lizards, frogs, eggs, and when the opportunity arises, small birds. [5] [6]
Predators of this species include humans, birds of prey, the king cobra, and the mongoose. [9] Large rats that have been bitten by this snake and are in a position to fight back, often do so. Although rare, large rats have been known to fatally wound the snake by scratching, biting, or even poking one or both of the snake's eyes out. Of course, the rat ends up succumbing to the venom, but the snake will often sustain eye injury, potentially becoming blind, and severe bites to the snout region leave the snake vulnerable to infections and diseases. [5]
Although venom toxicity values can vary greatly even among specimens of the same species, the Philippine cobra is considered to possess one of the more toxic venoms among the Naja (cobra) species. According to Tan et al., the murine LD50 via the IV route for this species is 0.18 mg/kg (0.11-0.3 mg/kg). [10] Data on venom yield of 150 milked N. philippinensis specimens (69 males; 81 females) gave an overall average venom yield per cobra per extraction of 0.33 ml (wet) or 70.1 mg (dried). [11]
The venom of the Philippine cobra is a potent postsynaptic neurotoxin which affects respiratory function and can cause neurotoxicity and respiratory paralysis, as the neurotoxins interrupt the transmission of nerve signals by binding to the neuromuscular junctions near the muscles. Research has shown its venom is purely a neurotoxin, with no apparent necrotizing components and no cardiotoxins. [12] These snakes are capable of accurately spitting their venom at a target up to 3 metres (9.8 ft) away. The symptoms of a bite might include headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, and difficulty breathing. [13] Bites by the Philippine cobra produce prominent neurotoxicity with minimal to no local signs. A study of 39 patients envenomed by the Philippine cobra was conducted in 1988. Neurotoxicity occurred in 38 cases and was the predominant clinical feature. Complete Respiratory failure developed in 19 patients, and was often rapid in onset; in three cases, apnea occurred within just 30 minutes of the bite. There were two deaths, both in patients who were moribund upon arrival at the hospital. Three patients developed necrosis, and 14 individuals with systemic symptoms had no local swelling at all. Both cardiotoxicity and reliable nonspecific signs of envenoming were absent. Bites by the Philippine cobra produce a distinctive clinical picture characterized by severe neurotoxicity of rapid onset and minimal local tissue damage. [12]
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 injected by unique fangs during a bite, whereas some species are also able to spit venom.
A ”spitting” cobra is any of several species of cobra that can intentionally, defensively shoot their venom directly from their fangs. This substance has two functions, with the first being as venom that can be absorbed via the victim’s eyes, mouth, or nose, and secondly as a toxungen, which can be sprayed on the target surface. Their ability to target and shoot venom is utilised in several different ways, self-defense being the most common instance. Studies have shown that the targets are far from random; rather, spitting cobras consciously take aim, directing their spray as close as possible to the eyes and face of an aggressor.
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.
The monocled cobra, also called monocellate cobra and Indian spitting cobra, is a venomous cobra species widespread across South and Southeast Asia and listed as Least Concern on the IUCN Red List.
The Caspian cobra, also called the Central Asian cobra, ladle snake, Oxus cobra, or Russian cobra, is a species of highly venomous snake in the family Elapidae. The species is endemic to Central Asia. Described by Karl Eichwald in 1831, it was for many years considered a subspecies of the Indian cobra until genetic analysis revealed it to be a distinct species.
Naja is a genus of venomous elapid snakes commonly known as cobras. Members of the genus Naja are the most widespread and the most widely recognized as "true" cobras. Various species occur in regions throughout Africa, Southwest Asia, South Asia, and Southeast Asia. Several other elapid species are also called "cobras", such as the king cobra and the rinkhals, but neither is a true cobra, in that they do not belong to the genus Naja, but instead each belong to monotypic genera Hemachatus and Ophiophagus.
The Egyptian cobra is one of the most venomous species of snakes in North Africa, and has caused many snakebite incidents to humans. It averages roughly 1.4 metres (4.6 ft), with the longest recorded specimen measuring 2.59 metres (8.5 ft).
Naja ashei, commonly known as Ashe's spitting cobra or the giant spitting cobra, is a species of venomous snake in the family Elapidae. The species is native to Africa. It is the world's largest species of spitting cobra.
The Indochinese spitting cobra also called the Thai spitting cobra, black and white spitting cobra, Siamese spitting cobra, is a species of spitting cobra found in Southeast Asia.
The black-necked spitting cobra is a species of spitting cobra found mostly in sub-Saharan Africa. They are moderately sized snakes that can grow to a length of 1.2 to 2.2 m in length. Their coloration and markings can vary considerably. They prey primarily on small rodents. They possess medically significant venom, although the mortality rate for untreated bites on humans is relatively low. Like other spitting cobras, they can eject venom from their fangs when threatened. The neurotoxic venom irritates the skin, causing blisters and inflammation, and can cause permanent blindness if the venom makes contact with the eyes and is not washed off.
The forest cobra, also commonly called the black cobra and the black and white-lipped cobra, is a species of highly venomous snake in the family Elapidae. The species is native to Africa, mostly the central and western parts of the continent. It is the largest true cobra species with a record length of 3.2 metres.
The Equatorial spitting cobra also called the Malayan spitting cobra, golden spitting cobra, Sumatran spitting cobra, or Palawan spitting cobra, is a species of spitting cobra found in Southeast Asia.
The Samar cobra also called Peters' cobra, southern Philippine cobra or Visayan cobra, is a highly venomous species of spitting cobra native to the Visayas and Mindanao island groups of the Philippines.
The Papuan black snake is a venomous snake of the family Elapidae native to New Guinea. Reaching around 2 m in length, it is a predominantly black snake coloured grey underneath.
Naja christyi, commonly known as the Congo water cobra or Christy's water cobra, is a species of venomous snakes belonging to the family Elapidae. The species is native to Sub-Saharan Africa.
Aspidelaps lubricus, commonly known as the Cape coral snake, Cape coral cobra or coral shield cobra, is a species of venomous snake in the family Elapidae. The species is endemic to southern Africa.
The Mandalay spitting cobra, also called the Burmese spitting cobra or Mandalay cobra, is a species of spitting cobra endemic to the Dry Zone in central Myanmar.
The Andaman cobra or Andaman spitting cobra is a species of cobra endemic to the Andaman Islands of India. The name of this cobra comes from the Islands itself. The species has a very potent venom, and is capable of “spitting”, although this defensive behavior is very rare and the aim is poor and not as efficient as “true spitting cobras”.
The Javan spitting cobra, also called Indonesian cobra or Komodo spitting cobra, is a species of cobra in the family Elapidae, found in the Lesser Sunda Islands of Indonesia, including Java, Bali, Lombok, Sumbawa, Flores, Komodo, and others.