Red-necked water snake

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Red-necked water snake
Red-necked water snake (Rhabdophis subminiatus) in Kaeng Krachan National Park

Red-necked water snake ( Rhabdophis subminiatus ) in Kaeng Krachan National Park

Systematics
Subordination : Snakes (serpentes)
Superfamily : Colubroidea
Family : Adders (Colubridae)
Subfamily : Water snakes (Natricinae)
Genre : Rhabdophis
Type : Red-necked water snake
Scientific name
Rhabdophis subminiatus
( Schlegel , 1837)
Red-necked water snake on Lantau Island

The red-necked water snake ( Rhabdophis subminiatus ) is a poisonous snake species from the subfamily of water snakes (Natricinae) that occurs in Asia .

features

The red-necked water snake reaches a maximum length of 130 centimeters. The upper side of the body shows an olive green to light brown color and is covered with a black-brown checkerboard pattern over almost the entire length of the body. Behind the gray or olive-green head with large flat scales stands out a V-shaped collar filled with black and bordered in yellow. The neck is colored orange-red to wine-red and gives this snake its common name. The species is equipped with neck glands that can secrete a poisonous secretion . The back is densely covered with small keel scales. The belly is ocher or gray. The eyes are large and black, the pupils are round.

Similar species

Due to the very characteristic drawing, the species is unmistakable.

distribution and habitat

The red-necked water snake is found in northeast India , Indonesia , Thailand , Vietnam , Cambodia , Laos , Myanmar , Malaysia , Singapore , Bhutan , Bangladesh , Nepal and southeast China . The species occurs predominantly near water, for example on the banks of streams, rivers and ponds. It has also been detected in swamps, on damp meadows and cultivated areas, especially in rice fields. The altitude distribution of the species extends from sea level to 1200 meters.

Way of life

The red-necked water snake is mostly active during the day and prefers to look for prey in damp terrain. She is generally not aggressive, however if cornered she can flatten her neck and hiss in a defensive S stance. The species reproduces through oviparia (laying eggs). The clutch can contain up to 14 eggs. Red-necked water snakes feed primarily on amphibians and fish, sometimes also on mice and lizards.

Toxicity

The division of snakes into poisonous and non-poisonous species is not without problems. The supposedly non-poisonous, so-called false snakes, have a simple poisonous apparatus. Their fangs are far back in the upper jaw. This is why the bite of these snakes is particularly important for smaller prey, such as B. mice and lizards. For humans, the bite, if it occurs in the arm or leg, is not dangerous for most snakes, since the poison teeth do not come into contact with the skin. However, life-threatening symptoms of poisoning can occur in humans, for. B. occur after a bite of the red-necked water snake in a finger. In such a case, therapy with blood exchange, erythrocyte concentrates , bolus administration of human fibrinogen and low-dose heparin proved to be successful, whereby the pronounced hemorrhagic diathesis could be controlled. The hemostaseological findings normalized after about four to five weeks . Most of the components of the poison are unknown, but it appears to contain toxins that affect blood clotting. Local pain, swelling, bleeding and blistering occur at the bite site. General signs are headache, nausea, vomiting, abdominal pain, diarrhea, cramps, dizziness and circulatory disorders leading to collapse. Typical is a coagulopathy . According to the Japan Snake Institute , Anti-Yamakagashi Antivenom is used as an antivenin .

Danger

The red-necked water snake is listed in India in the Wild Life Protection Act, 1972 in category IV, which results in penalties for violations that are much lower than for violations of the species listed with absolute protection in categories I and II.

The red-necked water snake is classified as " Least Concern = not at risk" by the World Conservation Organization IUCN .

Individual evidence

  1. ^ Thai National Parks - Species of Thailand
  2. ↑ a b Rhabdophis subminiatus (Schlegel, 1837) Red-necked Keelback , India Biodiversity Portal, Species Page, accessed April 2, 2021
  3. ↑ a b D. Paar, D. Mebs, N. Graben, U. Hassel, KD Bock: Life-threatening Afibrinogenemia after biting the "non-toxic" snake Rhabdophis subminiatus , 17th Hemophilia Symposium Hamburg, Springer-Verlag Berlin Heidelberg, 1988, ISBN 978-3-540-18065-4 , pp. 349-351
  4. ↑ antidote according Poison Center Munich, Booth 22 March 2016
  5. ↑ IUCN Red List for Red-necked Keelback Rhabdophis subminiatus

literature

  • MA Smith: The Fauna of British India, Ceylon and Burma including the whole of The Indo-Chinese Sub-region, Reptilia and Amphibia, Vol. 3, Serpentes , Taylor & Francis, London, 1943

Web links

Commons : Red-necked Water Snake  - Collection of images, videos, and audio files