The dim glow is typically confined to the digestive canals that underlie each of the comb rows. Ctenophores are strictly carnivorous and prey on a variety of planktonic animals. About 90 species inhabit all types of marine environments. Cydippid bodies are typically globular or pear-shaped. Lobate comb jellies typically have flattened oval-shaped bodies.
Tentacles are present but much reduced in size compared to cydippids.
Comb rows run along the aboral edge. These vicious beasts have the habit of using a large mouth to consume other comb jellies with reckless abandon. Like cnidarians, comb jellies are at the tissue level of organization. The body exterior is covered with a thin ectoderm that enters the mouth and lines the pharynx. The ctenophore mouth consists of a narrow slit, which leads into the compressed stomodaeum, or stomach formed by endodermal tissue.