Blobfish

The blobfish is a deep-sea fish in the fathead sculpin family (Psychrolutidae), found on the continental slopes off Australia and Tasmania at depths of 600-1200 m. It became internet-famous after being photographed out of water, where its normally neutral-buoyancy tissue collapses into a sagging, gelatinous mass under atmospheric pressure. In its natural high-pressure habitat, the blobfish looks far more like an ordinary, if soft-bodied, fish. It has no swim bladder; instead its low-density, jelly-like flesh keeps it buoyant with minimal muscular effort, an adaptation suited to the energy-poor deep sea. It is occasionally caught incidentally in deep-water trawls targeting other species.

Field marks for the blobfish:

• Soft, scaleless, gelatinous body lacking hard structures
• Large head with small, dark, closely set eyes
• Wide, downturned mouth giving a mournful expression
• Pinkish to greyish-brown coloration
• Reduced, soft fins with few or no spines
• No swim bladder

At depth its body holds a more rounded, fish-like shape; the famous drooping "blob" appearance only occurs after decompression at the surface. It is distinguished from other deep-sea sculpins by its unusually soft, low-density tissue and lack of scales or bony armor.

Blobfish live on the muddy and rocky continental slopes off the coasts of mainland Australia and Tasmania, generally at depths between 600 and 1200 meters. This zone is cold, dark, and under immense hydrostatic pressure, conditions the blobfish's gelatinous, low-density body is specifically adapted to withstand. They are bottom-associated, resting on or just above soft sediment rather than actively swimming through the water column. The lack of a swim bladder, which would be crushed or rendered ineffective at such depths, is compensated by flesh that is only slightly denser than seawater, allowing near-neutral buoyancy with minimal effort in an environment where food and energy are scarce.

Blobfish are solitary, slow-moving bottom dwellers that rely on minimal energy expenditure to survive in the food-scarce deep sea. Rather than actively pursuing prey, they are thought to sit and wait near the seafloor, engulfing small invertebrates such as crustaceans and mollusks that drift within reach. Their gelatinous body allows them to hover with little muscular effort, an efficient strategy given the scarcity of food at depth. Little is known about their reproduction, though related psychrolutid species are believed to lay eggs on the seafloor that the female may guard. Because they are rarely observed alive in their natural habitat, most behavioral details remain poorly documented.