Pterobranchia is a class of small, marine animals that belong to the phylum Hemichordata. They are primarily found in deep-sea environments and are characterized by their tube-like structures, which they use for shelter. Pterobranchs have a unique body plan, featuring a trunk and a series of tentacle-like arms that help them filter food from the water. These organisms are colonial, meaning they often live in groups, forming colonies that can consist of many individuals. Pterobranchs reproduce both sexually and asexually, contributing to their ability to thrive in various marine habitats. Their study provides insights into the evolution of deuterostomes, a group that includes chordates.