Blobfish (Psychrolutes marcidus)
The blobfish (Psychrolutes marcidus) is a fish that inhabits the deep waters off the coasts of Australia and Tasmania. Due to the inaccessibility of its habitat, it is rarely seen by humans.
Blobfish are found at depths where the pressure is several dozens of times higher than at sea level, which would likely make gas bladders inefficient. To remain buoyant, the flesh of the blobfish is primarily a gelatinous mass with a density slightly less than water; this allows the fish to float above the sea floor without expending energy on swimming. The relative lack of muscle is not a disadvantage as it primarily swallows edible matter that floats by in front it.