zooecium
/zoʊˈiʃiəm/
noun
- The protective case or tube that surrounds an individual animal in a colony of bryozoans (tiny aquatic animals).
- Each tiny bryozoan lives inside its own zooecium, which is made of calcium carbonate.
- Under a microscope, the zooecium looks like a small box or tube.
- The colony grows as new zoecia are added to the existing structure.