The annelid body plan

Annelids, such as earthworms and leeches, have a segmented body plan, meaning their bodies are made up of many repeating units called segments. These segments are separated by septa, internal walls that compartmentalize the body and help with movement and flexibility. Their bodies are elongated and cylindrical, with a true coelom (fluid-filled cavity) that supports internal organs. They have a nervous system with a simple brain and nerve cords, and they breathe through their skin. This segmented structure allows for efficient movement, growth, and specialization of body parts, making annelids adaptable to various environments.