Nomeus gronovii; Print; 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 200 to 1; 000 m (660 to 3; 280 ft). 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 39 cm (15 in). It is of minor importance to commercial fisheries. This species is the only known member of its genus.; 1700-1880