The ability of a living organism, to adapt to the most unfriendly environments and survive, is best exhibited by the awesome Angler Fish (living in the deepest parts of the Atlantic and Antarctic oceans). The dark depths of the ocean are devoid of light and available food, but the angler fish survives quite well–by employing ingenious methods and techniques.
There are over 200 different varieties of angler fish. The four types are Batfish, Goosefish, Frog fish and the Deep Sea Angler. Deep Sea Anglers can grow to a size of 4 feet, but most of them are smaller than this. All the fish that were caught turned out to be females. “How do they reproduce with out a male counterpart?” This was the question puzzling the scientists and researchers.
All the female anglers carried their own ‘fishing rods” with luminous bait attached to it. The lure was a modified dorsal fin and contained millions of light producing bacteria, emitting an eerie bluish or greening light.
Any fish attracted by the light approaches the dark and lurking angler, only to be swallowed whole! The large crescent shaped mouth and the expandable jaw opening wide, allow the angler to swallow prey twice its size! The long, sharp and curved teeth form a barrier and the prey has no means of escape, as it gets pushed into the stomach.
The elastic stomach can accommodate the large prey till they get digested and absorbed. The female angler is the classic example for the “lurk and lure” predator. Instead of going in search of its prey, it stays put in a place silently and lures the prey to come to it.
The sparsely populated fish, sprawled over a large ocean bed, find it difficult to get a suitable mate. The female angler has sorted out this problem in a unique way. The female angler is a giant (40 cm in length) in comparison with a male (a mere 2 cm long). The male angler fish has no luminous lure and never needs to feed him, by himself. His only task is to locate a female as quickly as possible and attach himself to her belly. He bites into her belly and fusion takes place. His teeth and jaw recede. His body fuses with that of the female and their blood stream get connected. He becomes a parasite for life, feeding off the female.
All his internal organs disappear slowly and he becomes just a bag of sperms (needed to fertilize the eggs released by the female). The fertilized eggs contain large droplets of oil, which give them the buoyancy, to rise to the surface of the ocean and hatch.
The female angler “lurks and lures” so that it can feed her mate–who has become a mere parasite, fused to her body. She also makes sure that her eggs stand a good chance of hatching, bringing in to the world more fish of her own kind!
Visalakshi Ramani