: Zooids secrete a protective chamber called a zooecium, which can be gelatinous, chitinous (like insect shells), or calcified (like coral).

: These species often form large, jelly-like masses that can grow to the size of a football. Finding them in a pond or lake is often a sign of good water quality , as they help clear the water by filtering silt and clay. Bryozoans (Moss Animals)

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

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.

: They possess a U-shaped digestive tract with both a mouth and an anus. Because the anus is located outside the tentacle crown, they are also known as Ectoprocta ("outside anus").