NCI 2024
    Groups
    Mammals Birds Amphibians Reptiles Myxini – Hagfishes Petromyz' – Lampreys Sharks & rays Animals Holocep' – Chimaeras Ray-finned fishes Dipneusti – Lungfish Gastropoda – Snails & slugs Coelac' – Coelacanths Insecta – Insects / bugs Arachnida – Spiders & scorpions Malacostraca – Malacostracans Diplopoda – Millipedes Bivalvia – Marine molluscs Cephalopoda – Squids & octopuses Chilopoda – Centipedes Pycnogonida – Sea spiders Merostomata – Horseshoe crabs More Classes
    Filters

    Regions

    See AllSelect

    Habitat

    See AllSelect

    Araneae – Spiders & allies

    Architects of the arachnid world

    They’ve set up homes in every nook and corner on Earth! They are the largest order of arachnids and are found all across the world, with the exception of Antarctica. Spiders play a vital ecological role, contributing to pest control and ecosystem balance.

    Their body consists of two parts, connected by a pedicel. They possess four pairs of eyes, with some species capable of forming images. Spiders use touch, chemical, and slit sensillae for various sensory functions, and some even use webs for hearing. Unlike insects, spiders lack antennae and mostly have a centralized nervous system.

    While most spiders are predators, some are herbivorous or scavengers. They use a variety of hunting techniques, including webs, silk lassos, mimicry, and active pursuit. Most spiders utilize venom to subdue prey, injecting digestive enzymes that liquefy internal tissues, as spiders’ digestive tracts are too tiny to ingest solids, they liquefy their meal by bombarding it with digestive enzymes.

    Araneae order first appeared during the Carboniferous period, which occurred approximately 359 to 299 million years ago.

    Despite their common association with spiders, daddy longlegs (harvestmen) are not true spiders. These arachnids belong to a separate order, Opiliones, and differ significantly in anatomy, lacking silk glands, venomous fangs, and the ability to produce silk.

    Did you know?

    • Spiders produce silk from specialized glands called spinnerets. Silk is not only used for webs but also for creating egg sacs, draglines, and safety lines.
    • Juveniles of certain spider families, including Thomisidae and Salticidae, have been observed feeding on plant nectar deliberately.
    • Females often invest significantly in offspring, either through guarding eggs or providing maternal care to spiderlings.
    • Human interactions with spiders vary, from fear to fascination. Some species, like the black widow or brown recluse, are medically significant, but most spiders are harmless and beneficial.
    • Visual acuity (clarity) of some jumping spiders is ten times better than that of dragonflies.