Beaked seasnake is a species of sea snake.

Description

The rostral scale is longer than broad, and is in contact with four shields; frontal more long than broad, shorter than the parietals; nasals in contact with the two anterior labials; sometimes partially divided; one pre- and one or two postoculars; temporals l—3; seven or eight upper labials, fourth or third and fourth entering the eye, the last sometimes divided; anterior chin-shields rather indistinct, separated. Scales with a tubercle or keel, in 50—70 rows; ventrals 230—314, slightly enlarged.
Uniformly dark grey above; sides and lower parts whitish. Young specimens olive or grey with black transverse bands, broadest in the middle. Length of head and body 1110 mm.; tail 190 mm.

The name valakadyn is from the Malayalam and Tamil word Vala kadiyan meaning net biter.

Distribution

It is found in the Arabian Sea

Arabian Sea

The Arabian Sea is a region of the Indian Ocean bounded on the east by India, on the north by Pakistan and Iran, on the west by the Arabian Peninsula, on the south, approximately, by a line between Cape Guardafui in northeastern Somalia and Kanyakumari in India...

 and Persian Gulf

Persian Gulf

The Persian Gulf, in Southwest Asia, is an extension of the Indian Ocean located between Iran and the Arabian Peninsula.The Persian Gulf was the focus of the 1980–1988 Iran-Iraq War, in which each side attacked the other's oil tankers...

 (off Oman

Oman

Oman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...

), south of the Seychelles

Seychelles

Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....

 and Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

, the seas off South Asia

South Asia

South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...

 (Pakistan

Pakistan

Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

, India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 and Bangladesh

Bangladesh

Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...

), Southeast Asia

Southeast Asia

Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

 (Myanmar

Myanmar

Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....

 (formerly Burma), Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

, Vietnam

Vietnam

Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...

), and Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 (Northern Territory

Northern Territory

The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...

 and Queensland

Queensland

Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

) and New Guinea

New Guinea

New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

.

Habitat and behaviour

These snakes are generally found in the coast and coastal islands of India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

. They are amongst the most common of the 20 kinds of sea snakes found in that region.

They are active both during the day and at night. They are able to dive up to 100 m and stay underwater for a maximum of five hours before resurfacing. Seasnakes are equipped with glands to eliminate excess salt. They are venomous and notably aggressive, with some herpetologists describing them as "cantankerous and savage" (Heatwole 1999, p. 121). About 1.5 milligrams of its venom is estimated to be lethal.

Their principal food is fish. The snake is also eaten as meat by Hong Kong

Hong Kong

Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...

 and Singapore

Singapore

Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...

 fishermen and locals alike.

Venom

The venom of this species is made up of highly potent neurotoxin

Neurotoxin

A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...

s and myotoxins

Myotoxin

Myotoxins are small, basic peptides found in snake venoms, such as in that of certain rattlesnakes. This involves a non-enzymatic mechanism that leads to severe muscle necrosis...

. This widespread species is responsible for the vast majority of deaths from sea snake

Hydrophiinae

Hydrophiinae, also known as sea snakes, is a group of venomous elapid snakes that inhabit marine environments for most or all of their lives. Though they evolved from terrestrial ancestors, most are extensively adapted to a fully aquatic life and are unable to move on land, except for the genus...

 bites (up to 90% of all sea snake bites). The value is 0.1125 mg/kg based on toxicology

Toxicology

Toxicology is a branch of biology, chemistry, and medicine concerned with the study of the adverse effects of chemicals on living organisms...

studies. The average venom yield per bite is approximately 7.9-9.0 mg, while the lethal human dose is estimated to be 1.5 mg. All seasnake antivenom is formulated using the Beaked sea snake venom.

Other sources

• Voris, Harold K. 1985 Population size estimates for a marine snake (Enhydrina schistosa ) in Malaysia Copeia 1985 (4): 955-961