Arixenia esau
| Arixenia esau | ||||||||||||
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Arixenia esau |
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| Scientific name | ||||||||||||
| Arixenia esau | ||||||||||||
| Jordan , 1909 |
Arixenia esau is a catchy tune , which, due to its different physique and behavior, is classified in its own superfamily Arixenioidae or even suborder (Arixeniina)with the genus consisting of three species. There is a close relationship to the Forficulina (especially to the family Labiidae or Spongiphoridae), the z. B. can be demonstrated by similarities in the construction of the neck.
features
The whole animal is light brown in color and has more or less long hairs (species name: Esau ; according to 1 Mos 27, 11 was “Esau rough, Jakob smooth”). The wings are reduced. The antennae are 13-segmented, but the pedicellus (the second segment) is noticeably elongated. The eyes are very small. The pronotum is much wider than usual in Dermapteren, the abdomen is narrowed behind, but (in the female) with 9 visible tergites ; the cerci are hairy, weak (not pincer-shaped), the mandibles are also hairy and three-toothed (otherwise always only two-toothed). Other special features concern the tentorium , the intestine and the gonads . The length is 16 to 20 millimeters.
Way of life
Arixenia was discovered in the skin folds of museum naked bats and was therefore prematurely referred to as their "ectoparasite". Anneliese Strenger (1977) refuted this on the basis of the structure of the mouth limbs, but the first person to describe it, Karl Jordan , expressed himself uncertainly in this regard. Rather, this catchy tune lives primarily predatory, also cannibalically. He is only synonymous with the bats in their caves (but not in total darkness) , walks around everywhere, from the walls to the ceiling, also on the bats that transmit it ( Cheiromeles and, although rarely, Tadarina ), but without harming them ( It is unclear whether he scrapes off skin flakes or uses the Molossids as Phorent ). The main food are smaller insects and mites that live in the excrement ( guano ) and especially on the fallen corpses of the bats. The density of individuals can be considerable. Freshly skinned nymphs ("larvae") or copulated adults who are dragged along and who cannot defend themselves well or escape are often eaten up and eaten. The cockroach Pycnoscelus indicus ( Blaberidae ) is likely to be an important predator .
Arixenia (the Greek word should say: "a very strange one") is, according to the circumstances, viviparous. Only one egg matures in each of the ovaries, the follicle of which then forms a pseudo placenta . A litter consists of about 6 nymphs, which are then quite large.
Occurrence
in caves on Borneo ( Sarawak ) and in Malaya (e.g. Selangor ), often together with the other species Arixenia jacobsoni .
literature
- Klaus Günther and Konrad Herter: Dermaptera. In: Handbuch der Zoologie, 4th vol., 2nd half, part 11, 158 pp., 1974
- Anneliese Strenger : Arixenia esau J., not a parasite - a functional morphological study. Zool. Number (Jena), 199, pp. 99-106, 1977