Jellyfish are a popular attraction at most public aquariums, and the Papuan jelly (Mastigias papua) is usually one of the few species that get a great deal of attention. Noted for their vibrantly spotted bells, these jellies are active swimmers that look great as they congregate in large groups. The reason they are so active is due to their constant collecting of sunlight, which feeds the symbiotic algae that lives within the jellyfish’s tissues. The algae, in exchange for the mobile protection, feed the jellies. This type of symbiosis is seen all over nature, especially in the aquarium trade with corals and anemones. We spotted these lovely jellyfish at the Houston Zoo, where there is a tank full of them. It’s a great sight that many people, especially the kids, get excited about.