Coffinfish

The coffinfish, or sea toad, Chaunax pictus, is a deep-sea anglerfish relative in the family Chaunacidae, found on continental slopes and seamounts worldwide at depths generally between 100 and 2000 meters. Its rounded, loosely skinned body and habit of inflating slightly when disturbed give rise to the common name "sea toad," while "coffinfish" references early taxonomic descriptions of its box-like proportions. Like its anglerfish relatives, it possesses a small retractable lure, or illicium, positioned above its mouth, used to attract prey in the dark. Rather than swimming actively, coffinfish move across the seafloor using their modified, limb-like paired fins, an unusual locomotion strategy among fishes.

Distinguishing features of the coffinfish:

• Rounded, balloon-like body covered in loose, baggy skin
• Small fine spines scattered over the pinkish-orange to reddish skin
• Large, wide mouth positioned near the top of the head
• Small, upward-facing eyes
• Short, stout, arm-like pectoral and pelvic fins used for walking
• Small retractable lure (illicium) tucked in a groove above the mouth

Coffinfish are distinguished from true anglerfishes by their globular, box-like body shape, uniformly loose baggy skin, and shorter, less elaborate lure, along with their characteristic fin-assisted walking gait along the seafloor.

Coffinfish inhabit soft sediment and rocky substrates on continental slopes and seamounts across tropical to temperate oceans worldwide, typically at depths from around 100 to 2000 meters. This deep benthic zone receives little to no light, and coffinfish rely on their lure and camouflaged coloration rather than vision-dependent hunting strategies used by shallow-water fish. They are bottom-dwelling and rarely found in the open water column, instead remaining closely associated with the seafloor across their range. Their distribution spans multiple ocean basins, reflecting the broad depth tolerance and adaptability of the Chaunacidae family to the cold, high-pressure conditions of the deep continental margin.

Coffinfish are ambush predators that remain largely stationary on the seafloor, using their small illicium lure to attract curious fish and invertebrates close enough to engulf with a rapid, wide-mouthed strike. Rather than swimming for locomotion, they typically "walk" slowly across the sediment using their stubby, limb-like pectoral and pelvic fins, an energy-efficient method suited to the food-scarce deep sea. When disturbed, they are known to gulp water and inflate their loose, baggy skin, a possible defensive or startle response. They are generally solitary, and reproduction is not well documented, though like related anglerfishes they are thought to release buoyant egg masses into the water column.