Arachnids

the Arachnids (Arachnida) are a class that Gliederfüsser (Arthropoda). Together with the arrow tail cancers they form for the Unterstamm of the Kieferklauenträger (Chelicerata).

Their body is lower partable in two parts , Cephalothorax (head chest) and abdomen (abdomen). They can both clearly of each other separately (e.g. Web spiders, scorpios) or not separatelyits (weber farmhands, mites). There is present eight run legs; further extremities are reshuffled to tools such as poison claws, shears, tracers or mouth tools.

reproduction and development

Mating of the wolf spider

with the reproduction gives it various variations. Since all kinds are landliving, there is very frequently an internal fertilization by penisähnliche structures (for instance with weber farmhands). The males of other groups as for instance the scorpios as well as most mitesplacing sperm cells packages (Spermatophoren), which are taken up by the females. The males of most Web spiders fill their Bulbi in the Pedipalpen at their own sex organ or on Spermatophoren even woven. The Bulbi becomes with the mating into thoseEpigastralfurche of the females imported.

[Work on]

systematics

the following orders are contained:

• Scorpios (Scorpiones)
• scourge scorpios (Uropygi)
• dwarf scourge scorpios (Schizomida)
• scourge spiders (Amblypygi)
• Web spiders (Araneae)
• Palpenläufer = tracer runner (Palpigradi)
• pseudo scorpios (Pseudoscorpiones)
• roller spiders (Solifugae)
• weber farmhands (Opiliones)
• Kapuzenspinnen (Ricinulei)
• mites (Acari)

simplified Kladogramm after Schultz,1997, quote in: The Tree OF would run Project, Arachnida. Further fragmentations are also --||-- suggested.

        |------------  Palpenläufer (Palpigradi)    |--|   |--------  Web spiders (Aranea)    |  |--|   |----  Scourge spiders (Amblypygi)    |      |--|  |-- Thelyphonida --||--  Scourge scorpios (Uropygi) |--|          |--|--  Schizomida| | ||_____________|--Kapuzenspinnen (Ricinulei) --|                |--  Mites (Acari) | |          |-------  Weber farmhands (Opiliones) |---------|  |---- Scorpionida --||--Scorpios (Scorpiones)            |--|  |--  Pseudo scorpios (Pseudoscorpiones)               |--|--  Roller spiders (Solifugae)

[work on]

literature

• Ax P (1999): “The system of the Metazoa II. A text book thatphylogenetischen systematics "; Gustav Fischer publishing house.
• Braddy, S. J., R. J. Aldridge, S. E. Gabbott, and J. N. Theron. 1999. Lamellate implications. Zoological journal OF the Linnean Society 97:1 - 56.
• Morphology, taxonomy and Phylogenie of the Chelicerata. I. Morphologic
• Weygoldt, P. 1998. Evolutionand systematics OF the Chelicerata. Experimental & Applied Acarology 22:63 - 79.

[Work on]

Web on the left of

Commons: Arachnids - pictures, videos and/or audio files