They look like jellyfish but ctenophores (comb jellies) are totally different animals that have their own phylum. Ctenophores don’t sting but use sticky cells to catch their prey. They swim using comb plates made of tiny hairs (cilia) fused together. The beautiful rainbow colour patterns visible here are caused by refraction of light in the glass-like comb plates acting like a prism. Some species also produce light themselves.