A cydippid ctenophore (comb jelly).
Ctenophore
Image courtesy of the NOAA Office of Ocean Exploration and Research, Mountains in the Deep: Exploring the Central Pacific Basin. Download larger version (jpg, 893 KB).

A cydippid ctenophore (comb jelly). Ctenophores come in a surprising number of different shapes, but all have in common eight rows of ctenes (or combs) that are rows of ciliated cells. As these ctenes beat, they can sometimes cause beautiful rainbow-like refractions that many people mistake for bioluminescence. This ctenophore has two long tentacles that help it to capture prey.

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