Portuguese man o' war
The Atlantic Portuguese man o' war lives at the surface of the ocean. The gas-filled bladder, or pneumatophore, remains at the surface, while the remainder is submerged. As the Portuguese man o' war has no means of propulsion, they move according to the winds, currents, and tides. Although they are most commonly found in the open ocean in tropical and subtropical regions, they have been found as far north as the Bay of Fundy, Cape Breton and the Hebrides.
Man-of-war fish
Nomeus gronovii, the man-of-war fish, or bluebottle fish, is a species of fish in the family Nomeidae, the driftfish. It is native to the Atlantic, Pacific and Indian Oceans, where adults are generally found at depths from . It is notable for its ability to live within the deadly tentacles of a siphonophore, the Portuguese man o' war, upon whose tentacles and gonads it feeds. The fish is striped with blackish-blue blemishes covering its body, and the caudal fin is extremely forked. It can reach a length of . It is of minor importance to commercial fisheries. This species is the only known member of its genus.