Arthropods

Arthropods are invertebrate animals that have an exoskeleton, a segmented body, and jointed appendages. They include insects, arachnids, crustaceans, and myriapods.

Arthropods have no backbone (they are invertebrates).

The main groups of arthropods are insects, arachnids, crustaceans, and myriapods.

Crustaceans are a class of arthropods that typically have a hard exoskeleton, two pairs of antennae, and are mostly aquatic. Examples include crabs, lobsters, and shrimp.

Arachnids are a class of arthropods that have eight legs, no antennae, and include spiders, scorpions, and ticks.

The exoskeleton provides protection, support, and prevents water loss in arthropods.

Arthropods grow through a process called molting, where they shed their exoskeleton to allow for growth.

Jointed appendages allow for greater mobility and flexibility, enabling arthropods to perform various functions such as walking, swimming, and grasping.

Most arthropods breathe through structures called tracheae or gills, depending on whether they are terrestrial or aquatic.

Complete metamorphosis involves four stages: egg, larva, pupa, and adult. Incomplete metamorphosis involves three stages: egg, nymph, and adult.