Ctenophores, or comb jellies, look like jellyfish—but they aren't. They have eight rows of cillia along the body, which give them their name. They are generally small, the largest being only 7-10 cm. They can be seen inhabiting the water column at most diving depths.
They have either two tentacles, or none at all. They are favorite subjects of photographers due to the multi-colored light reflections from the undulating cillia. They lack the stinging nematocycts of the jellyfish, so must resort to adhesive tentacles and grasping lobes to capture prey, which is composed of tiny planktonic marine animals.