Portuguese man o' war
The Portuguese man o' war is often found with many different kinds of marine fish. Some of them are shepherd fish, clown fish, and yellow jack. These species are rarely found anywhere else. The clown fish can swim among the tentacles without being stung. This is possibly due to its mucus that does not trigger the nematocysts. The shepherd fish seems to avoid the larger, stinging tentacles. It feeds on the smaller tentacles under the gas bladder. These fish benefit from the shelter of the stinging tentacles. It also helps the man o' war: the presence of these species may attract other fish to feed on.