May 17, 2022
A polyp is one of two morphological stages of a cnidarian. Polyps attach to the seabed and capture food using tentacles at the top, often mistaken for plants. The typical structure of a polyp is a narrow tube with a widened base on the aboral side (i.e. away from the mouth opening) and a tentacle whorl on the oral side. Almost all polyps are sessile. Some species have developed a pelagic way of life (such as Velella). In colonial form, polyps can grow into extensive reefs. In colonial forms the feet of the different individuals are fused together. Many cnidarians are polyps for only part of their life cycle. The other life stage is called meduse.