Tiger otters
| Tiger otters | ||||||||||||
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Black tiger otter ( N. ater ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Notechis | ||||||||||||
| Boulenger , 1896 |
The tiger otters ( Notechis ) are a genus of the Elapidae family ( poisonous snakes ). It includes two species, the black tiger otter ( N. ater ) and the common tiger otter ( N. scutatus ) as well as several subspecies whose distribution is restricted to southern Australia .
features
The two species reach body lengths of over one meter, whereby the common tiger otter with a maximum total length of about 1.20 meters is not quite as long as the black tiger otter with a body length of up to about 1.50 meters. The basic color of the common tiger otter is very variable and ranges from light gray to olive green, brown or brownish red with more or less pronounced crossbars; in very rare cases black animals also occur. The black tiger otter, on the other hand, is always black in color. The belly side is lighter in color than the back side in both species.
The large, almost square frontal shield on the top of the head is characteristic of the genus . The anterior temporal is also very large and at least as long as or longer than the anterior . Subocularia are absent, but an internasal is formed. All body scales are smooth and form 17 to 21 rows of scales in the middle of the body, whereby the common tiger otter usually has 19 and the black tiger otter usually has 17 rows of scales. The ventral side is made up of more than 140 ventralia , with the black tiger otter having at least 155 ventralia. The maximum number of both species is 190 ventralia. Both the anal shield and the subcaudalia are undivided.
distribution and habitat
Tiger otters are found exclusively in the south of Australia, whereby the ranges of the two species do not overlap. The black tiger otter lives on the southwestern tip of Western Australia and Tasmania , while the common tiger otter is distributed from south Queensland via New South Wales to Victoria in the area of the Murray and Murrumbidgee Rivers and the extreme south-east of South Australia .
The snakes live mainly in the highlands and are found there in a number of different habitats . In the north, these can be wet rainforests in particular, while in the south they occur in drier areas.
Way of life
Both tiger otters are mainly active during the day and at twilight, and night activity occurs on particularly hot days. The offspring are born alive, the snakes are correspondingly ovoviviparous .
Snake venom
The tiger otters are considered to be very dangerous snakes because they have a very potent venom and also come into frequent contact with humans. Accordingly, a very large proportion of fatal snakebite accidents in Australia can be attributed to the two species of this genus. An antivenin against the venom was developed very early and the composition and effects of snake venom have been very well researched.
literature
- Harold G. Cogger: Reptiles & Amphibians of Australia. 6th edition. Ralph Curtis Books, Sanibel, Florida 2000, ISBN 0-88359-048-4 , pp. 658-660.
