Which type of circulatory system is present in annelids?

Annelids, which are a diverse group of segmented worms including earthworms and leeches, have a closed circulatory system. In a closed circulatory system, blood is confined to vessels (blood vessels), and it circulates throughout the body within these vessels. The blood is pumped by a muscular pump, typically a heart, and it carries oxygen, nutrients, and other substances to the various tissues and organs of the annelid's body. This closed circulatory system is more efficient than an open circulatory system, which is found in some other invertebrates, because it allows for more precise control over the distribution of oxygen and nutrients to different body parts.