Psychrolutes marcidus

Psychrolutes marcidus, the smooth-head blobfish, also known simply as blobfish, is a deep sea fish of the family Psychrolutidae. It inhabits the deep waters off the coasts of mainland Australia and Tasmania, as well as the waters of New Zealand.

Blobfish are typically shorter than 30 cm (12 in). They live at depths between 600 and 1,200 m (2,000 and 3,900 ft) where the pressure is 60 to 120 times greater than that at sea level, which would likely make gas bladders inefficient for maintaining buoyancy. Instead, the flesh of the blobfish is primarily a gelatinous mass with a density slightly less than that of water; this allows the fish to float above the sea floor without expending energy on swimming. The blobfish has a relative lack of muscle, but this is not a disadvantage as its main food source is edible matter that floats in front of it, such as deep-ocean crustaceans.

Blobfish are often caught as bycatch in bottom trawling nets.

The popular impression of the blobfish as bulbous and gelatinous is partially an artifact of the decompression damage done to specimens when they are brought to the surface from the extreme depths in which they live. In their natural environment, blobfish appear more typical of their superclass Osteichthyes (bony fish).