Bryozoa

, commonly known as "moss animals," are a phylum of microscopic aquatic invertebrates that live in sedentary colonies. While they are often mistaken for coral, seaweed, or even gelatinous "blobs," they are a distinct group of filter-feeders found in both marine and freshwater environments. Biological Structure and Anatomy

Bryozoan colonies are made up of individual units called . These zooids are typically less than 1 millimeter long and cooperate to ensure the colony's survival. bryozoa

: In many marine species, zooids are specialized for different tasks, such as feeding ( autozooids ), defense ( avicularia ), or cleaning the colony ( vibracula ). Habitat and Environment , commonly known as "moss animals," are a

: Zooids secrete a protective chamber called a zooecium, which can be gelatinous, chitinous (like insect shells), or calcified (like coral). These zooids are typically less than 1 millimeter

: Each zooid has a "crown" of ciliated tentacles called a lophophore used to filter food like phytoplankton and bacteria from the water.

: Most species live in the ocean, ranging from tropical coral reefs to polar waters and even deep-ocean trenches. They often encrust rocks, shells, and kelp.