arachnid ()

Arachnids, members of Arachnida, are a large class of arthropods, with most adults possessing multiple legs, multiple eyes, mandibles and/or other facial appendages such as chelicerae and pedipalps, and generally large and/or elongated abdomens. The most well known arachnids are spiders and scorpions.

Nearly all adult arachnids have 8 legs, differentiating them from general insects who typically have 6. Also, unlike insects, they lack antennae as well as wings. Their bodies are covered in a tough exoskeleton, some being covered in fur or hairs known as urticating hairs, used as a form of defensive irritant. Almost all arachnids are terrestrial, though a few live within freshwater and marine environments. Quite a few arachnids utilize various, similar defensive and hunting mechanisms, often related to piercing the skin of the predator or their prey with claws, pincers, stingers, or fangs. A lot of arachnids utilize this piercing alongside a form of venom.

Families, genera, and species

Related

General anatomy

Other rankings