There are about 150 known species of comb jellies or ctenophores that inhabit the oceans of the world. Despite their jelly-like composition and appearance, ctenophores are not the same as jellyfish. Adult ctenophores possess eight rows of fused cilia (called combs) used for swimming. They are the largest animals to swim by using cilia. The combs produce dynamic rainbow patterns caused by diffraction of light passing between the rows of beating cilia. This particular species of comb jelly, Beroe sp., is a voracious predator with specialized ciliary teeth in its large mouth, which it uses to capture smaller ctenophores or to bite pieces out of larger ones.
This image was collected during a dive at a depth of 15 meters in the White Sea at the edge of the Polar Circle (water temperature around zero degrees Celsius). The ctenophore is 6cm. long.
Alexander Semenov, White Sea Biological Station, Moscow State University, Russia