Deep Sea Angler Fish
|DEEP SEA ANGLER FISH (Melanocetus johnsonii)
An angler is another word for fisherman. So, anglerfish are named after their fishing-rod style of catching prey. There are about 200 species of anglerfish in the oceans of the world. Each one has a slightly different way of fishing. The Deep Sea Anglerfish uses an altered dorsal spine above its head to dangle a glowing lure in front of potential prey. When the prey swims close to see what it is – snaps – the anglerfish clamps down on it with a mouthful of sharp teeth.
They live deep in oceans throughout the world, over 3000 feet down, where little light penetrates the darkness. In this location, they can take advantage of the shadows to hide from both predators and prey. They use a chemical reaction called bioluminescence to light up their fishing lure. In this process, special cells release luciferin and luciferase, two chemicals which, when mixed with ATP, create light with very little heat. The resulting blue-green light is similar to that produced by the firefly.
The Deep Sea Anglerfish is unusual for another reason. When they were first studies, scientists had a difficult time finding a male anglerfish. They also noticed that some females had parasites – small, sucker-like fish that had inserted their heads into the female’s sides. After further study, it became clear that the small parasites were actually the male anglerfish. Latching on to the female helped them mate and gave them a free meal from the female’s digestive system – the tradeoff was that they were stuck there permanently after mating.
Although it looks ferocious, the anglerfish is a small fish – about 5 inches long and not a fast swimmer. Its roundish body results in more of a wiggle as it moves through the water, rather than the seamless glide of more hydrodynamic fish. But it can compensate for its small size and sluggish swim with stealth, and its jaws and stomach extend to a supersize capacity to fit in prey that is bigger than itself.