Arachnida

The class Arachnida comprises about 100,000 described species and certainly many more that are undescribed. the ones that are well-known to most people are the true spiders (Araneae) and scorpions (Scorpiones). Harvestman or daddy-long-legs (Opiliones) and mites (Acari, including ticks) are also arachnids, with many species occurring in all parts of the world. Not so well-known are the species-poor groups of the tropics: Amblypygi (Tailless whip scorpions), Palpigradi (microwhip scorpions), Schizomida and Thelyphonida (whip scorpions), Ricinulei (hooded tickspiders) and Solifugae (camel spiders).

All arachnids have a body which is separated into a cephalothorax (called the prosoma) and the abdomen (opisthosoma). The prosoma carries the four pairs of legs and two further pairs of appendages which are used for feeding (the chelicerae), sensory perception, defense and reproduction (the pedipalps).  

Most of the 1021 voucher specimens of the digitized arachnid collection were collected in Central Europe or in South America and are conserved in ethanol.

True spiders (Araneae) and oribatid mites (Oribatida) are in individual collections, due to the much higher number of specimens.

Zu den Ordnungen Araneae (Webspinnen) und der Unterordnung Oribatida (Hornmilben) der Milben liegen wesentlich größere Belegzahlen vor, die in eigenen Sammlungen verwaltet werden.