Bryozoum, also known as bryozoan, is a noun that refers to a member of a phylum of tiny aquatic invertebrate animals. Bryozoans are colonial animals, meaning they live together in large groups called colonies, which can range from a few individuals to millions. These colonies are characterized by a branching or encrusting structure that forms various shapes, such as mats, sheets, or pillars.
Each individual bryozoan (zooid) in the colony is encased within a hard, calcareous or chitinous exoskeleton, also known as a zooecium. The zooids are small, usually measuring less than a millimeter in size, and have a tentacle-filled feeding apparatus called a lophophore, used for filter-feeding. Through the lophophore, bryozoans extract microscopic organisms, such as algae and plankton, from the surrounding water, converting them into food.
Bryozoums are found in both freshwater and marine environments worldwide, including rivers, lakes, and oceans, with some species even adapting to live in brackish water. They often attach themselves to a substrate such as rocks, shells, or plants, although some species can form free-floating colonies. Bryozoans play significant ecological roles, providing habitats for other organisms and contributing to the stabilization of sediments.
The study of bryozoans is known as bryozoology, and researchers have identified and described thousands of different species belonging to this phylum. Bryozoans have a long evolutionary history, with fossil records dating back to the Early Ordovician period, over 485 million years ago. Their diverse forms and ecological functions make bryozoans an important component of aquatic ecosystems.
