TWIL #020 - The Coffinfish Walks on the Seafloor and Inflates Like a Balloon
The coffinfish is a deep-sea anglerfish that walks on modified fins, inflates itself with water when threatened, and uses a lure to hunt in total darkness.
- #animals
- #marine-biology
- #deep-sea
The coffinfish (Chaunax species, family Chaunacidae) is a deep-sea anglerfish with an unusual set of talents. It lives on the seafloor at depths of 100 to 2,000 metres and does something most fish don't: it walks.
Rather than swimming continuously, the coffinfish uses its fleshy, arm-like pectoral fins to push itself along the bottom in a slow, deliberate shuffling gait. It's not fast, but it doesn't need to be - the seafloor prey it hunts isn't going anywhere quickly either.
Like other anglerfish, it has a modified dorsal spine (the illicium) that acts as a lure, dangling in front of its mouth to attract prey. In the near-zero-visibility environment of the deep sea, small fish and invertebrates are drawn to the movement and bio-luminescent glow.
Its most dramatic defence is inflation. When threatened, the coffinfish can rapidly gulp in water and inflate itself to roughly double its normal size, making it much harder to swallow and giving it the boxy, coffin-shaped appearance that gives the fish its name.
It's a fish that walks, fishes with a lure, and inflates itself when scared - the deep sea continues to produce things that look like they were designed by a committee that disagreed on everything.