Collet black otter
| Collet black otter | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Pseudechis colletti |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Pseudechis colletti | ||||||||||||
| Boulenger , 1902 |
The Collet black otter ( Pseudechis colletti ), also Collett's black otter , is a species of snake from the family of poisonous snakes and belongs to the genus of black otters ( Pseudechis ). It was first described in 1902 by the Belgian zoologist George Boulenger . The epithet honors the Norwegian naturalist Robert Collett .
features
Pseudechis colletti has a slim, but strong build and reaches a length between 1.2 and 1.3 m, maximum sizes of 1.8 m are documented. Males tend to grow larger than females. The head is only slightly separated from the neck. The eyes have a round pupil . The color of this species is extremely variable. The top of the trunk can be brown to black, the flanks can be pink to cream colored. These bands mix towards the middle of the back and create an irregular pattern with spots and cross bars. The ventral side is yellowish to orange in color. The Pholidose shows the following characteristics: seven upper lip shields ( Scuta supralabials ), 19 rows of smooth scales in oblique rows around the center of the body ( Scuta dorsalia ), 215-235 abdominal shields ( Scuta Ventralia ) and 50 to 70 under tail shields ( Scuta subcaudals ) and an undivided Anal shield ( Scutum anal ).
Poison apparatus
As a poisonous snake, Pseudechis colletti has a venomous apparatus with proteroglyphic teeth. The front upper jaw has slightly elongated, immobile fangs with a groove for the application of poison. The poison secretion is produced in poison glands (specialized salivary glands on the side of the head) and reaches the fangs via a poison channel.
Snake venom
Up to 48 mg (dry weight) of poisonous secretions are released with one bite. The mean lethal dose (LD 50 ) is given as 1.38 mg / kg ( subcutaneous , mouse ). Poisoning occurs in 40 to 60% of bite accidents. The mortality from untreated intoxication is 20 to 30%. The toxin mixture contains various toxins . Myotoxins and anticoagulants are of medical importance . Neurotoxins may be present but are of no clinical relevance. After a poison bite, local symptoms such as pain and edema appear first . Systemically, unspecific general symptoms may appear (e.g. nausea , vomiting , headache , abdominal pain ). The myotoxic components damage muscle tissue . Anticoagulants inhibit blood clotting , which may lead to hemorrhages (bleeding). Secondary cardiotoxicity (damage to the heart, impairment of cardiac function) can also occur. Serious complications can result from secondary kidney damage as a result of released myoglobin from muscle tissue. There are Antivenine (z. B. 'Black Snake Antivenom', CSL Limited ) are available which with rapid application can prevent serious damage, but over already made tissue damage are not effective by the toxins.
Way of life
Pseudechis colletti leads a ground-dwelling and, especially under high outside temperatures, predominantly nocturnal way of life. During the day the species is mostly hidden. Animal structures, caves and crevices or cracks in dried-out clay soil can serve as shelter. After heavy rains it can be found outside of the hiding places. The range of prey includes amphibians , lizards , snakes , birds and small mammals . Cannibalistic behavior was also observed. When provoked , Pseudechis colletti shows defensive behavior in which the front body (as is typical for black otters) is flattened. In addition, the animal hisses and excretes secretions with a noticeable smell. Ultimately, it can lead to a defensive bite with poison release. The propagation is done by oviparity so oviparous. The clutch contains between 6 and 19 eggs.
Occurrence
The distribution area of Pseudechis colletti lies within Australia in the interior of the state of Queensland . Populated habitats are represented by arid areas.
Individual evidence
- ^ A b G. A. Boulenger: Description of a new snake of the genus Pseudechis from Queensland. In: The Annals and Magazine of Natural History; Zoology, Botany, and Geology , Vol. 10, Series 7, pp. 494-495, 1902. (digitized version )
- ↑ WCH Clinical Toxinology Resources, The University of Adelaide: Pseudechis colletti (accessed September 17, 2017)
literature
- Trutnau: Snakes in the Terrarium, Vol. 2 Poison Snakes , Verlag Eugen Ulmer, 1998.
