Dionycha (spiders)
The division of living beings into systematics is a continuous subject of research. Different systematic classifications exist side by side and one after the other. The taxon treated here has become obsolete due to new research or is not part of the group systematics presented in the German-language Wikipedia.
Dionycha form a group of the genuine spiders (Araneomorphae: Entelegynae) at their Fußendgliedern ( tarsi ) has two claws carry.
The most species-rich family of jumping spiders (Salticidae), the superfamily of the Gnaphosoidea , the crab spiders (Thomisidae), the sack spiders (Clubionidae), a total of 17 families, are assigned to the approximately 10,000 species of Dionycha . Members of the Dionycha have more highly developed sense organs than other arachnids , above all they have a well-developed sense of sight, and even surprise with courtship dances or courtship songs.
Presumably the Dionycha developed from the net-building Trionycha , maybe they are a paraphyletic group - the relationships are still unclear. In contrast to Trionycha, Dionycha only have two instead of three tarsal claws and are therefore also known as two-clawed spiders or modern walking spiders , as many of them do not weave any nets . This small difference is decisive for very different ways of life and thus also for the development of the spiders (Aranea).
The bristled central claw responsible for the safe gripping and guiding of the silk thread in the three-clawed spiders is missing in the Dionycha. In their place are dense tufts of scopula hair , which generate strong adhesive forces and turn some species into pronounced climbers, sprinters and jumpers. The prey is not caught and spun in sticky nets , but mostly actively hunted by ambushing and sneaking up. Species of the superfamily Lycosoidea such as wolf spiders and lynx spiders are hunting spiders, but belong to the Trionycha. The ability to produce silk is used in a variety of other ways, for example for caves, egg cocoons or safety lines ( jumping spiders ).
The hunting strategy required a further development of the sensory organs, the legs and thus a striking morphological redesign. In addition to the acoustic, tactile and chemical senses typical of spiders, jumping spiders in particular have a good sense of sight and an astonishingly nervous performance and speed. This is also linked to a more differentiated internal communication , for example some species perform courtship dances, communicate stridulatory and some males have eye-catching jewelry.
The Dionycha include, for example:
- Bark sac spiders (Corinnidae)
- Field spiders (Liocranidae)
- Gnaphosoidea (7 families)
- Bag spiders (Clubionidae, over 2000 species)
- Tender spiders (Anyphaenidae)
- Jumping spiders (Salticidae,> 4000 species)
- Crab spiders (Thomisidae,> 3000 species)
- Running spiders (Philodromidae)
- Giant crab spiders (Sparassidae)
- Selenopidae
literature
- J. Bosselaers and R. Jocqué. 2002. Studies in Corinnidae: cladistic analysis of 38 corinnid and liocranid genera, and transfer of Phrurolithinae. Zoologica Scripta 31: 241-270.
- JA Coddington and HW Levi. 1991. Systematics and evolution of spiders (Araneae). Annual Review of Ecology and Systematics 22: 565-592.
Web links
Single receipts
- ^ A b Foelix, Rainer: Biology of spiders. Oxford University Press, 2010, ISBN 978-0-19-973482-5
- ↑ Wunderlich, Jörg: To determine the most common fossil spiders in Baltic amber. Black on White (on the subject of amber) 1997, pp. 185–195.