Spiders, unlike insects, have only two main body parts (tagmata) instead of three: a fused head and thorax (called a cephalothorax or prosoma) and an abdomen (also called an opisthosoma). The exception to this rule are the assassin spiders in the family Archaeidae, whose cephalothorax is divided into two parts by an elongated "neck".

Spiders (order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, [2] and spinnerets that extrude silk. [3] They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms.

The external and internal structures of spiders, including skin, muscles, breathing system, digestive tract and reproductive organs. Unlike an insect, the spider's body is in two sections. The head and thorax, bearing the eyes, mouthparts and …

Feb 19, 2025 · From the innocent daddy longlegs to the harmful brown recluse, here are the most common house spiders, how to identify them, and when to worry about a bite, according to entomologists.

Aug 16, 2023 · Spider bites can range from minor annoyances to potentially harmful situations. Recognizing the distinct characteristics of different spider bites is crucial for both accurate identification and appropriate treatment.

Dec 15, 2019 · Did you find a spider in the U.S and you would like to identify it? Then you are at the right place. This page will help you identify your spider. Simply read through the content on this site and answer the questions below, and you will hopefully identify your spider. If not, you can still reach out to us (more details below).

For an overview of spiders in your US state, click on any of the states on the map below. If the map is too small on mobile devices, just scroll down to get to the alphabetical link list of all US states and their most common spiders.

Mar 22, 2025 · spider, (order Araneida or Araneae), any of more than 46,700 species of arachnids that differ from insects in having eight legs rather than six and in having the body divided into two parts rather than three. The use of silk is highly developed among spiders.

All spiders have two body regions (cephalothorax and unsegmented abdomen), eight legs (each with seven segments), a pair of pedipalps, a pair of chelicerae (jaws) and either six or eight simple eyes .

Jan 20, 2025 · Spiders, classified under Araneae (the largest order of Arachnids), represent a diverse group of air-breathing arthropods known for their distinctive anatomical features.