Question: choanocytes are found in which phylum?
Answer: Choanocytes (also known as "collar cells") are cells that line the interior of asconoid, syconoid and leuconoid body type sponges that contain a central flagellum, or cilium, surrounded by a collar of microvilli which are connected by a thin membrane. They make up Choanoderm, a type of cell layer found in sponges.