Stinging hairs in tarantulas
Stinging hairs in tarantulas can occur in New World tarantulas . They are purely a defense mechanism against predators . The hair is on the abdomen ( opisthosoma ) or on the buttons. There are five different types of stinging hair and these are used by arachnologists for the taxonomic description of the genera and species.
Bombardier spider
Bombardier spiders is a term that is mainly used in German-speaking terraristics and describes tarantulas with stinging hairs on their abdomen. This term can be found in relevant literature on terraristics and is also used by the German arachnologist Günter Schmidt in scientific publications. In other languages, however, the authors refer to the presence of stinging hairs, each of which has a taxonomic relevance. There is no analogous name for the bombardier spider in other languages.
Tarantula species are called bombardier spiders because many of them, when threatened, strip off the stinging hair with a rear leg and fling the hair towards the attacker. This process is reminiscent of a bombardment and is therefore also known as "bombing". Predators with their head (snout) close to the supposed prey, breathe this hair in or get it in their eyes. The mucous membranes of the respiratory tract or the eyes are immediately irritated by a purely mechanical irritation triggered by these stinging hairs and thus lead to the attacker fleeing. Not all tarantulas with stinging hairs hurl them at the attacker. Some only stretch their backside towards the supposed predator so that the stinging hairs loosen when touched and thus penetrate the mucous membranes of the attacker's nose and eyes. Although these spiders do not bomb, they are still called bombarding spiders because of the presence of the stinging hairs.
behavior
The stripping of stinging hairs for defense in the genus Avicularia was described by Henry Walter Bates in an article as early as 1863 :
"The hairs with which they are clothed come off when touched, and cause a peculiar and almost maddening irritation."
"The hairs that cover them fall off when you touch them and cause conspicuous and almost unbearable skin irritation."
In some animals, however, the stinging hairs are not only stripped off when defending themselves, but also to line their living tubes. In this way, you protect your building from possible attackers so that they cannot scout out the tube with their snout. The more this hair is stripped off, the sooner the animals get bald on the opisthosoma. The hair is completely renewed when it sheds.
Systematics
The bombardier spiders are always New World tarantulas. These include the species in the Theraphosinae subfamily that strip off the stinging hairs with a back leg. In the subfamily Aviculariinae , the rear part is usually stretched out towards the attacker. An exception is Caribena versicolor , which also sheds stinging hair with a back leg. Another exception are species of the genus Ephebopus , which have stinging hairs not on their abdomen, but on their buttons. You rub the button abruptly on the bite claws to insert the stinging hair.
morphology
There are five different types of stinging hair. Four were first described by John AL Cooke, Vincent D. Roth and Frederick H. Millers and published in 1972. In 1996, Fernando Pérez-Miles scientifically described a fifth species in the tarantula species Hemirrhagus cervinus .
Skin reactions in humans
In humans, stinging hair can cause allergic reactions. Symptoms are inflammation, rashes, or severe itching. These symptoms can last for hours to days. Although the stinging hairs only irritate mechanically, a different reaction can occur depending on the person or the affected area (e.g. mucous membranes in the eyes). Some symptoms can be alleviated with steroids and antihistamines .
gallery
Example of a bombing Brachypelma boehmei
Example of the defense behavior of Avicularia cf. bicegoi . The opposite stretching of the rear part provided with stinging hair.
A Brachypelma smithi with a clearly bald spot after removing stinging hairs
With Grammostola species, the stinging hairs act like a reflective surface
Web links
Individual evidence
- ^ Günter Schmidt: The tarantulas, Westarp-Wissenschaften, 2003
- ^ Bates, HW (1863). The naturalist on the River Amazons, a record of adventures, habits of animals, sketches of Brazilian and Indian life and aspects of nature under the Equator during eleven years of travel. London: J. Murray.
- ↑ a b Pérez-Miles, F. (1998a). Notes on the systematics of the little known theraphosid spider Hemirrhagus cervinus, with a description of a new type of urticating hair. Journal of Arachnology 26: 120-123.
- ↑ a b Bertani, R .; Boston, T .; Evenou, Y .; Guadanucci, JPL (2003). "Release of urticating hairs by Avicularia versicolor (Walckenaer, 1837) (Araneae, Theraphosidae)". Bulletin of the British Arachnological Society 12 (9): 395-398.
- ↑ Eckardt, D. "Unusual defensive display in Avicularia versicolor." Journal of the British Tarantula Society 8 (1992).
- ↑ Cooke, J .A .L., VD. Roth & EH. Miller. 1972. The urticating hairs of theraphoside spiders. American Mus. Nov, 2498: 1-43.
- ↑ Chao-Kai Hsu, Mark Ming-Long Hsur, Rick C. West, Yau-I Chu: Skin Injury Caused by Urticating Hair of Tarantula. Dermatologica Sinica. September 2007, pp. 232-237