I saw a bit of a nature show, but can't remember the name of this animal. It's an under water micro-organism(?) that, when roused by movement, glows. It was more or less an oval shape and I think that they were looking at it with an infrared light. They showed them floating around a crustacean's moving antennae, and behind a squid. It"ts name started with an "N". Do you know what it is?
You may be referring to a dinoflagellate called Noctiluca scintillans, commonly known as the sea sparkle. Dinoflagellates are algae, which are protists, not animals.