Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about 0.5 millimetres (1⁄64 in) long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869 living species are known.
Byozoan colonies
![A freshwater bryozoan colony](https://npr.brightspotcdn.com/dims4/default/b0155d3/2147483647/strip/true/crop/790x440+0+0/resize/880x490!/quality/90/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2Flegacy%2Fsites%2Fwltr%2Ffiles%2F201709%2Fbryozoans-crop.jpg)
Florida Fish and Wildlife Conservation Commission