The ocean, it is one of the most beautiful environments on our planet. But below the waves, there is a whole new world of amazing creatures. Some beautiful, some terrifying and some that are both! But go even deeper, where sunlight can’t reach and where the water is ice cold, and be ready to Meet, the deep sea anglerfish, one of the weirdest looking fish in the sea, scientifically known as Melanocetus johnsoni.
It is nicknamed as “common black devil” most likely for its sharp, translucent, fang-like teeth and insanely big mouth. It can stretch its mouth as large as a volleyball and also can stretch its stomach to eat prey twice its body size. This unusual adaptation allows it to store food when prey is scarce.
The deep sea anglerfish has a round-shaped body that resembles a basketball. The mouth is usually the biggest part of their body. This is actually a small fish, reaching length of only about five inches. But, some deep sea angler fish can grow up to 4 feet!! Their color can range from brown to dark gray or black. It has no scales, just a soft body.
Their skin is specially adapted to bounce back blue light and so appears invisible to other deep-sea animals. The first ray of its dorsal fin is modified into a filament called an illicium with a sac containing millions of bacteria at the tip called an esca. This light-producing organ is also known as a photophore. These bacteria glow through a chemical process known as bioluminescence!
The anglerfish is known to remain completely motionless. It uses a muscular skin flap to either hide or reveal its lighted lure which is highly steerable. By pulsing the light and moving the lure back and forth like a fishing pole, they successfully attract pelagic crustaceans, and fishes.
When the prey gets close enough, the angler engulfs it with its powerful jaws and swallows it whole. The sharp teeth of the angler are slanted inwardly and some even fold in under pressure, which helps to restrain the prey from escaping.
They don’t actively hunt, and just “wobble” through the water. However it can swim fastly when in danger.
Strangely they are also known to swim inverted occasionally.
The only individuals that fit the above description are the females!
The male angler is non predatory, and about the size of a small finger. When a male angler matures, its digestive system degenerates, making it incapable of feeding. It uses its strong sense of smell and follow pheromones to find females.
A female uses its lure to attract a mate. The male angler attach itself to the female biting with its small hook teeth. He then liberates an enzyme that dissolves the skin of his mouth and that of her body. Their blood vessels join.
His eyes and all other internal organs except the testes are lost. The male will live the rest of his life joined to the female like a parasite. A female can carry up to 12 males on her body at a time. The female releases her eggs into the water column, followed by the male releasing his sperm.
The anglerfish breeds in the spring and summer. The fertilized eggs are laid in a thin sheet of gelatinous material which float freely in the sea until the eggs hatch into tiny larvae. Once hatched, the larvae swim to the surface of the ocean and feed on plankton. They return to the depths below after maturation.[1]The deep-sea anglerfish genus Acentrophryne (Teleostei, Ceratioidei, Linophrynidae) in the Miocene of California: Journal of Vertebrate Paleontology: Vol 29, No 2 (tandfonline.com)
Reviewed by:
Dr. Muhammad Khalid Mukhtar (Ph.D.)
University of Sargodha, Sargodha