Denizens of the Deep
By Sophia Read
For The Bali Times
SEMINYAK ~ Most life in the ocean depends, as we do above the waves, on sunlight. The vast majority of marine life exists in the epipelagic zone, which stretches down to 200 meters before light attenuates and ceases to support photosynthesis. Creatures that etch out an existence below this zone are some of the weirdest forms of life known to man.
Because of the enormous difficulties of underwater exploration at this depth â€“ the pressures involved are tremendous â€“ we know very little about the vast majority of the creatures that live in this aphotic or no-light zone.
Scientists split the depths of the ocean into four zones: the Mesopelagic, or Twilight zone (200mâ€“1000m); the Bathypelagic (1000mâ€“4000m)zone; the Abyssopelagic zone (4000mâ€“the ocean floor); and the Hadopelagic zone, which describes the water in the deepest ocean trenches.
Down in the Abyssal zone, there is no light at all, and the temperature is about 3 degrees Centigrade. Life, however, will find a way, even in the most inhospitable of circumstances, and the denizens of this underwater world are weird and wonderful in the adaptations.
The Humpback Anglerfish (pictured), or Black Seadevil, will strike most as truly grotesque. Aside from its deeply unattractive appearance, it, and many other deep-sea creatures, is armed will phenomenally sharp and powerful teeth. Their skin is black, and so thin that it will come off if touched by human hand. With no available light, searching for the necessities of life (food, a mate) becomes a challenging task. The Seadevil has adapted two ingenious ways to solve this problem. The female has a fishing lure â€“ a modified dorsal spine with a bioluminescent tip, which attracts what little life there is into her cavernous jaws.
For reproduction, deep-sea anglerfish have developed what may be described as perhaps the most bizarre system of all. The females of the species are equipped with everything one might expect â€“ eyes, stomach, gills etc. – and grows to about 12 inches long. The male, however, is a different kettle of fish; they are tiny, and from birth have only one purpose: to find a female. Having once done so, the male latches onto the female, and is subsequently pretty much absorbed into her body. It looses its stomach and nervous system, surviving on the nutrients from her body. It becomes, essentially, a sack of spermatozoa, carried around by the female.
At these depths, creatures seem to go to extremes to survive. Gigantism is common, and can be seen in creatures such as the King of Herrings (grows up to 11 meters), giant crabs and other crustaceans, most famously, the Giant, and, more recently, the Colossal Squid. Only last year a single Colossal Squid was caught off New Zealand and taken back to New Zealand for study. Its total length was more than 10 meters. The Colossal Squid and its close cousin the Giant Squid are often characterized as ferocious monsters.
Their existence had been posited from the scars found on the deep-diving Sperm Whale, and from the stomach contents of whales that were caught (squid beaks are particularly indigestible). From his evidence, sailors created the myths we know today of giant squid attacking ships, and monsters rising from the deeps to raise havoc on unwary souls. I hate to disappoint Pirates of the Caribbean fans, but the Kraken â€“ just not possible.
We know so very, very little about the deep sea; we have barely even begun to explore its wonders and meet its inhabitants. Only last month a deep-sea expedition led to the discovery of six new species previously unknown to science, not different color variations, but six entirely new species that we had no idea existed.
As our resources run ever closer to exhaustion, many eyes are turning to the only truly undiscovered realm on Earth for answers. The creatures that exist without sunlight have adaptations that may well teach us how to survive in a world that we have raped and overpopulated.
The writer is sales manager of AquaMarine Diving â€“ Bali.
Filed under: The Island