Sargassum fish to the seaweed, where it is fertilised by the male. On hatching, each larva is surrounded by an integumentary envelope and has a large, rounded head, fully formed fins, and eyes with double notches. As the larva develops into a juvenile, this envelope fuses with the skin. This fish is preyed on by larger fish and sea birds. To avoid underwater threats, it can leap above the surface onto mats of weed. It can survive for some time out of water. Sargassum fish The sargassum fish, anglerfish, or frog fish ("Histrio histrio") is a frogfish of the family Antennariidae, the
Sargassum muticum observed in temperate environments. "Sargassum muticum" grows from half-tide to infralittoral areas (to a depth of 10 m.). It is fixed on solid substrates like rocks, stones, shells. It is highly tolerant towards temperature and salinity variations. The optimal temperature is between 17 and 20 °C but it tolerates -9 and 30 °C. Originally from Japan, it is thought to have gained worldwide distribution through being transported with Japanese oysters ("Crassostrea gigas"). "Sargassum muticum" was introduced to the Californian coast in the 40's and in Europe in the 70's (The species was first found in the British Isles in the