The Javan spitting cobra (''Naja sputatrix''), also called Indonesian cobra, is a species of cobra in the family

Elapidae Elapidae (, commonly known as elapids ; grc, ἔλλοψ ''éllops'' "sea-fish") 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 Emydoce ...

, found in the Lesser Sunda Islands of

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

, including

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...

, Bali,

Lombok Lombok is an island in West Nusa Tenggara province, Indonesia. It forms part of the chain of the Lesser Sunda Islands, with the Lombok Strait separating it from Bali to the west and the Alas Strait between it and Sumbawa to the east. It is ...

Sumbawa Sumbawa is an Indonesian island, located in the middle of the Lesser Sunda Islands chain, with Lombok to the west, Flores to the east, and Sumba further to the southeast. Along with Lombok, it forms the province of West Nusa Tenggara, but th ...

, Flores, Komodo, and others.

Etymology and names

''Naja sputatrix'' is classified under the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Naja ''Naja'' is a genus of venomous elapid snakes commonly known as cobras (or "true cobras"). Members of the genus ''Naja'' are the most widespread and the most widely recognized as "true" cobras. Various species occur in regions throughout Afric ...

'' of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

. It was first described by

German German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

entomologist,

herpetologist Herpetology (from Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians ( gymnophiona)) and rep ...

, ornithologist, and lawyer

Friedrich Boie Friedrich Boie (4 June 1789 – 3 March 1870) was a German entomologist, herpetologist, ornithologist, and lawyer.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins Universit ...

in 1827.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . ("Boie", p. 31). The

generic Generic or generics may refer to: In business * Generic term, a common name used for a range or class of similar things not protected by trademark * Generic brand, a brand for a product that does not have an associated brand or trademark, other ...

name ''Naja'' is a Latinisation of the

Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...

word ' (), meaning "cobra". The

specific Specific may refer to: * Specificity (disambiguation) * Specific, a cure or therapy for a specific illness Law * Specific deterrence, focussed on an individual * Specific finding, intermediate verdict used by a jury in determining the fina ...

epithet ''sputatrix'' comes from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word ''sputator'', which means ''"spitter."''

Description

The Java spitting cobra is a medium to large sized snake and has long cervical ribs, capable of expanding to form a hood when threatened. The body of this species is compressed dorsoventrally and posteriorly cylindrical. The average length of an adult is , but they can grow to a maximum of around . The head is elliptical, slightly different from the neck with a short rounded snout and large nostrils. Its eyes are of moderate size, with round pupils. The dorsal scales are smooth and very oblique. Dorsal scale count is usually 25–19. Some colouration and pattern differences occur between

n specimens and those from the other islands where this species occurs. Javan adults are usually uniform yellowish, brown or blackish in colour, while juveniles often have throat bands and lateral throat spots. Specimens do not always have hood marks, but when there is a mark, it is most often chevron-shaped.

Distribution

This species of cobra is native to the Indonesian islands of

and the Lesser Sunda Islands of Bali,

, Komodo, Flores,

Lomblen Lembata is an island in the Lesser Sunda Islands, also known as Lomblen island; it is the largest island of the Solor Archipelago, in the Lesser Sunda Islands, Indonesia. It forms a separate regency of the province of Nusa Tenggara Timur. The leng ...

, and Alor. They may possibly occur in the other islands in the group. One was found on Rinca Island on 26 December 2015. Verification is still required as to whether or not this species of cobra also occurs in the islands of

Timor Timor is an island at the southern end of Maritime Southeast Asia, in the north of the Timor Sea. The island is divided between the sovereign states of East Timor on the eastern part and Indonesia on the western part. The Indonesian part, also ...

and Sulawesi. Although a single specimen was observed in the island of Sulawesi, it is thought that the specimen may have originated from the island of Java, as it was indistinguishable from Javan specimens. Scientist De Hass did research on this species in two districts of western Java: in Nandjoeng Djaja, where it was relatively uncommon and in Bandjarwangi, where the altitude is it was not recorded. A 1998 study by FB Yuwono found the species was abundant in Java. Dunn (1927b) reported specimens taken on Komodo from sea level to , the highest altitude this species has been found at.

Habitat, behaviour and ecology

The Javan spitting cobra is found mostly in tropical forests and wet forest, but the species adapts well to a wide variety of habitats across its range on the islands, including more arid regions, dry woodlands, and cultivated hill country. In the island of Komodo, it has been observed in a variety of habitats including dry

savanna A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

and deciduous monsoon forest. It has also been reported that specimens in the island of Komodo are reluctant to spit, but field observations suggest the opposite. This species is easy prey for the

Komodo dragon The Komodo dragon (''Varanus komodoensis''), also known as the Komodo monitor, is a member of the monitor lizard family Varanidae that is endemic to the Indonesian islands of Komodo, Rinca, Flores, and Gili Motang. It is the largest extant ...

. Naja sputatrix is very defensive and readily spits out venom when it feels threatened. It is a terrestrial snake that's nocturnal in nature. It preys predominantly on small mammals such as small rats and mice, but it will also feed on frogs, other snakes, and lizards. Herpetologist Shine Boeadi, in a study published in 1998, measured and dissected 80 Javan specimens of this species and found that most prey items were mammals.

Reproduction

Mating occurs during the dry season (August to October). Females often lay eggs at the end of the dry season in November or the very beginning of the wet season. As many as 13 to 19 eggs may be laid in a clutch, the average is about 16 eggs. Javan females may produce and lay up to 36 eggs, but on average only 25 eggs are produced. The incubation period is about 88 days according to Kopstein. Like other elapids, hatchlings are completely independent from birth.

Conservation Status

This species is listed as Appendix II by CITES meaning this species is not threatened with extinction, but may become so unless trade in specimens of such species is subject to strict regulation in order to avoid utilization incompatible with the survival of the species in the wild. They are commonly harvested for their skins. They are also occasionally found in the pet trade.

Venom

The LD₅₀ or (median lethal dose) of the crude venom of this species is 0.90 mg/kg IV (0.59-1.36 mg/kg). The most significant constituents of the venom include high-molecular-weight proteins and enzymes, phospholipase A2 enzymes, postsynaptic

neurotoxins Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature nerv ...

and polypeptide

cardiotoxin Cardiotoxicity is the occurrence of heart dysfunction as electric or muscle damage, resulting in heart toxicity. The heart becomes weaker and is not as efficient in pumping blood. Cardiotoxicity may be caused by chemotherapy (a usual example is th ...

s, meaning although the venom may be potent, it may not be particularly rapid-acting. Like all cobra species, this species' venom also consists of postsynaptic neurotoxins. However, the main components of its venom are cardiotoxins with cytotoxic activity. In fact, polypeptide cardiotoxins make up 60% of the venom (dry weight), while postsynaptic neurotoxins make up only 4.5%. The two main neurotoxins, sputa-neurotoxin 1 (SN1) and sputa-neurotoxin 2 (SN2) isolated from the venom, are "short" neurotoxins, with 62 and 61 amino acid residues, respectively. The IV LD₅₀ of the two toxins are 0.09 mg/g and 0.07 mg/g, respectively, and they possess amino acid sequences similar to those of other cobra venom neurotoxins. The venom was also found to exhibit an in vitro anticoagulant activity much stronger than most common cobra (genus ''Naja'') venoms. The anticoagulants, phospholipase A2 enzymes, with a molecular weight of approximately 14 kDa, make up 15% of the venom (dry weight). Very few human fatalities are attributed to this species.