What type of organism is a spider classified as?

A spider is classified as an arachnid due to its distinct morphological and physiological characteristics that belong to this group of invertebrates. Arachnids, which include spiders, scorpions, ticks, and mites, are characterized by having eight legs, a two-part body structure (cephalothorax and abdomen), and lack antennae, which distinguishes them from insects that have six legs and a three-part body structure. Additionally, arachnids have specialized mouthparts, known as chelicerae, which are adapted for feeding on their prey.

This classification is essential for understanding the biological and ecological roles arachnids play in their environments, as well as their evolutionary relationships with other arthropods. Recognizing this classification helps in studying various aspects of arachnids, including their behaviors, habitats, and the contributions they make to ecosystems as both predators and prey.