Unsolved Mysteries of the Sea
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Puffer fish (Lagocephalus).
Cone snails, which inhabit tidal pools and beach areas, as well as offshore habitats, are also venomously toxic. They have a device not unlike a built-in hypodermic needle that helps them to kill their prey. If injected into a human being, their toxin can induce severe pain, loss of sensation, heart attack, and unconsciousness.
The moray eel isn’t one of the marine toxic team, but its powerful jaws and a set of teeth that combine the most dangerous features of razors and stilettos make him an unpleasant guy to encounter. He inhabits crevices, tidal pools, the undersides of rocks — almost any location where he’s not generally expected. Dead fish, or a few drops of blood from an angler’s hook-in-the-finger type injury, will attract him powerfully. Those formidable teeth can do more than superficial tissue damage: the moray eel’s dentition will get through a victim’s nerves and tendons if they come within range.
Artist’s impression of dangerous eel-type creature, or ribbon fish.
Needle fish stay near the surface as a rule and turn up in bays, inlets, estuaries, and open waters. As the name suggests, they have a very long, pointed jaw — another of the sea’s many biological mysteries. They are attracted by light and by any bright, gleaming, or glittering objects. When that long, abnormally pointed jaw pierces a victim, it tends to break off in the wound. Another strangely elongated jaw belongs to the tobacco-pipe fish (Fistularia tabacaria).
Tobacco-pipe fish (Fistularia tabacaria).
Dinosaurs are venerable, but the coelacanth is older still. It was thought to have become extinct when they did around 65 million years ago — but it didn’t! The reappearance of the amazing — not to mention controversial — coelacanth with its 400-million-year pedigree took place in 1938. A highly intelligent and proactive museum curator, Marjorie Courtenay Latimer, worked in the port of East London, situated northeast of Cape Town, South Africa. Her friend Captain Hendrick Goosen commanded the trawler Nerine. An arrangement they had that was of great benefit to Marjorie’s museum was that whenever the Nerine docked in East London, Hendrick invited her over to inspect the cargo in case there were any unusual or interesting specimens among his newly caught fish. On December 23, 1938, there most certainly was!
The Nerine had been trawling off the mouth of the River Chalumna, and as Marjorie inspected the pile of dead fish she spotted an unusual blue fin sticking out. Moving sharks and rays aside to reveal the late owner of that mysterious and intriguing blue fin, Marjorie saw the unforgettable bluish-purple body and iridescent silver markings of what could only have been a coelacanth. She took it back to her museum, sketched it, and sent the sketch to an eminent ichthyologist, Professor J.L.B. Smith of Rhodes University. He sent back the now famous cable: “Most important preserve skeleton and gills.” When he reached East London and examined what was left of the coelacanth he described it as the most important zoological find of the century.
Reward notices were posted everywhere in the area in the hope of finding more specimens, but it was not until 1952 that the next coelacanth was discovered. Captain Eric Hunt of the Nduwaro was doing all he could to locate one as he traded among the Comoros Islands in the Mozambique Channel. As a result of Hunt’s work in spreading Professor Smith’s reward notices, two local men, Ahamadi Abdallah and his friend Affane Mohamed, duly brought in a coelacanth. Ahamadi had caught it on his handline. Although not common, the species was well enough known to the Comorians of Anjouan Island, who referred to them as Gombessa or mame fish.
Urgent messages to Professor Smith brought him flying over in a DC3 Dakota. He confirmed that Ahamadi had indeed caught a coelacanth. Worldwide publicity and great excitement naturally followed.
The tragic corollary to the story is the mysterious disappearance of boldly adventurous Captain Eric Hunt of the Nduwaro. Four years after being instrumental in bringing Professor Smith’s wonderful ichthyological dream to life, Hunt’s ship was wrecked on the dangerous Geyser Bank between Madagascar and the Comoros. Hunt was never found.
The stingray — another mystery of the sea — is one of a vast range of cartilaginous fish (Elasmobranchii) including many other rays, skate, ratfish, and sharks. The ray’s pedigree covers millions of years: fossils of their earliest antecedents go back to Jurassic times — 150 million years ago. Their powerful, flexible bodies are supported by tough, fibrous cartilage instead of bone. Rays are related to sharks, from which they evolved. The stingray has spines on its tail capable of poisoning an attacker. In some species the tail is long and moves like a whip. In others, it is little more than a stump. The rays vary enormously in colour: sometimes males and females of the same species are differently pigmented.
Elasmobranchii — a typical member of the ray family.
The smallest known ray is referred to as the short-nosed electric ray, weighing about half a kilogram and being only ten centimetres in diameter. The biggest of its cousins is the mighty manta ray (Manta birostris), with a diameter of nine metres and a mass of several tonnes. Despite its vast size, the manta ray is a swift and elegant swimmer — although its style differs from that of most normal fish. Its wing-like pectoral fins propel it by rippling and flapping. These big pectoral fins make it possible for it to glide through the water, rather as gliding birds go through the air. The diet of this enormous denizen of the deep consists of minute fish and microscopic plankton, enlivened with a sprinkling of very small crustaceans. It directs food into its mouth by using the cephalic lobes situated just ahead of its eyes.
Other rays eat fish, molluscs, worms, and crustaceans. Some hunt for their prey on the ocean floor. Others stun it with an electric charge. Rays are remarkably talented — the mangrove stingray, for example, can even jump out of the water! Their feats in the water — including the speed with which they swim — are due in part to some species being coated with slippery mucous that greatly reduces water-drag. Most fish have a swim bladder, which controls the depth at which they swim. Rays — like sharks — don’t have one. Their buoyancy is controlled by their large, oily livers, but when they stop swimming, rays sink down to the ocean floor.
The strangely misnamed angelfish, also called monkfish and fiddle fish, is a voracious predator equipped with five rows of very effective teeth in a mouth — unlike the mouths of its cousins — situated at the far end of its large head. It claims kinship with the plagiostomi, the fish group that includes rays and sharks and other creatures that can reach a length of three metres.
Squatina angelus — known as angelfish, fiddle fish, and monkfish.
As far as can be ascertained, some plagiostomi, including rays, are highly intelligent — and some are amazingly gregarious and sociable, living together in colonies thousands strong. Others, hermit-like, prefer to be loners. They usually express curiosity when divers approach them, although they can survive at astounding depths — up to three thousand metres below sea level — far beyond normal diving range! The blind electric ray (Typhlonarke aysoni) can also survive at phenomenal depths. Specimens are said to exist as far down as nine hundred metres. Visibility is very restricted at that level, and, consequently, its eyes appear to be almost non-functional, but it “sees” using electro-receptors and is capable of delivering powerful electric shocks.
The mangrove stingray’s ability to leap out of the water is impressive, but it pales into insignificance beside the aerial antics of flying fish. Known technically as Exocoetidae, flying fish are gregarious, swimming in schools or shoals. In length they range from eighteen to thirty centimetres, and they possess pectoral fins that rival the wings of birds. Many species also have pelvic fins that are much larger than those of traditional fish.
Technically, flying fish do not actually fly like birds, but rather glide. They get airborne by approaching the surface of the sea at speeds of up to fifty kilometres an hour. Then they taxi along the surface like small aircraft attempting a takeoff by using their remarkable tail fins almost like rear-end propellers! Unlike its cousins, the characin flying fish found arou
nd the Amazon Basin really does fly by using its fins like wings and buzzing them like a bumblebee. It’s the misfortune of the flying fish to be appetizing to dolphins, mackerel, and tuna — and their aeronautics are essential to their survival when these predators are after them.
Flying fish (Exocoetidae).
Among the strangest and most mysterious denizens of the deep are the angler fish. There are well over two hundred species of them, named because of their technique of what resembles fishing. Their “fishing rods” are actually spines of their dorsal fins, with a lure — often luminous — dangling on the end. Prey, fascinated by this “bait,” comes too close — and is promptly eaten.
Angler fish.
The sex life of the angler fish is even stranger than its food-gathering techniques. Only the female has the built-in fishing tackle. The male is much smaller than his mate and lives on her as a permanent parasite. The nuptials consist of the male giving the female a hearty bite and attaching himself. His mouth adheres to her skin and they are literally inseparable thereafter. He blends his bloodstream with hers and becomes totally dependent on her for nourishment. As time passes, he loses his eyes, followed by his internal organs — and remains solely as a source of sperm: the ultimate example, perhaps, of Darwinian survival mechanisms at their most economical!
One of the largely mythical terrors of the deep is the giant clam, Tridacna gigas, which is supposedly able to trap a diver’s legs and drown him. Admittedly, the giant clam can reach a width of well over a metre and a weight of 250 kilograms, but it would be hard pressed to trap a diver between its bivalvular shells because it has to empty its water chamber before it can get the shells to close — and this takes several seconds! Unless the diver who has been careless enough to put his foot between the giant clam’s two shells has a reaction speed that makes a sloth look like Billy the Kid drawing a Colt .45, he ought to be well clear of the closure hazard before the clam has got a quarter of its water chamber empty. Human beings are of more danger to the giant clam than it is to us. There are reports of souvenir giant clam shells being used as birdbaths and baptismal fonts in churches. Furthermore, some gourmets regard the clam’s flesh as both a delicacy and an aphrodisiac— a reputation that does nothing for its life expectancy.
Best known — and most feared — of all marine predators are the members of the sinister shark family. They come in a wide range of shapes and sizes, the hammerhead being one of the more spectacular. Big hammerheads can reach a length of six metres and a weight of 250 kilograms. They are ferocious predators with voracious appetites. Their diet includes squid, octopus, crustaceans, rays, and other sharks. Hammerheads are migratory and travel to cooler waters in summer. They give birth to live young, averaging about thirty pups, with an average length of seventy-five centimetres.
Hammerhead shark (Zygaena malleus). The great hammerhead is Sphyrna mokarran.
The most dangerous of all sharks is the great white. Big specimens can reach a length of seven metres and a mass of well over three tonnes: the females are bigger than the males! Their diet is rather more varied than the hammerhead’s menu and can include otters, seals, and sea lions as well as belugas and sea turtles: nothing edible is safe! Despite possessing about three thousand teeth, which move around into place as required, great whites don’t chew their food — they simply rip it into suitably sized pieces and swallow it whole. They can also go for a week or two between meals.
This shark’s ability to sense even the tiniest drop of blood in the water is phenomenal — a concentration of one part blood in ten million parts of water is apparently detectable to a great white’s nostrils. They can also pick up minute electrical charges from prospective prey, so being detected by one is all too easy if you’re swimming anywhere in its vicinity — especially if it hasn’t eaten anything substantial for a month or two! They have fewer simultaneous pups than the hammerheads: a great white manages only about ten at a time. Their life spans are not known with any certainty, but some marine biologists estimate they can probably live for about a century.
Early nineteenth-century artist’s impression of a great white shark.
Big and dangerous as the great whites undeniably are, the biggest of all creatures are the whales. They are members of the cetacean family, which includes nearly eighty species of whales, porpoises, and dolphins. One of this great family, the blue whale, is the largest living creature that has ever existed on Earth — including the mightiest of the dinosaurs. Blue whales are about thirty metres long.
Many of the sea’s biological mysteries centre on whales. Their behaviour includes logging, where they rest just below the surface with part of the huge back and head exposed above the water and the tail resting in the downwards position. The many semi-legendary, but very persistent, stories of mariners landing on what they thought were small islands could be based on sailors’ stories of actual landings on logging whales. Other mysterious whale activities include lob-tailing, where they slap the water with their tails; spy-hopping, where they lift their heads out of the water and rotate as though looking around; and breaching, where they leap clear out of the water — a prodigious feat considering the vast body mass involved.
Nineteenth-century concepts of whaling.
Unlike baby sharks, which have to fend for themselves as soon as they’re born, baby whales — referred to as calves — are nursed and protected by their mothers for at least a year and often significantly longer. Whales are highly intelligent and often gregarious, frequently moving around together in what are known as pods. It is practically certain that they have systems of social relationships, too. The famous whale song — part of that social behaviour — can last for more than half an hour and can carry over great expanses of water.
Although killer whales attack smaller members of the family, human beings are the only known predators of the giant whales, and it seems to the authors that the hunting and killing of these magnificent, intelligent, and sociable ocean giants is not only morally questionable but an inadequate commercial use of a unique natural resource. Sea film safaris and whale-spotting holiday tours would produce ten times the income available from whale hunting. Co-author Lionel makes that statement authoritatively and categorically as a practising professional management consultant and a fellow of the Chartered Institute of Management. The whale has to face enough natural hazards without the human race adding to them unnecessarily. As recently as November 2003, for example, more than one hundred pilot whales were found dead at Point Hibbs on the Tasmanian coast. Had they gone too far inshore during a feeding frenzy? Or had they been trying to escape from predators?
A beached whale.
Another great mystery of whales is the question of where they originated. Just as many sea creatures gradually emerged from the water during evolutionary millennia, so whales appear to have gone the other way — from the land to the sea. One interesting theory of whale development is that they came from land mammals with hooves. About 50 million years ago there was a land-dweller, known to science as Mesonychid, that may have returned to the sea and become the whale’s ancestor.
So we conclude this chapter with a reference to Goldsmith’s pioneering work in the eighteenth century, and a salute to the prominent pioneering Canadian marine scientists of our own day, Professor Myers and Professor Hebert: In that extensive and undiscovered abode, millions reside, whose manners are a secret to us, and whose very form is unknown.
CHAPTER NINE
Perilous Waters
Draw three lines connecting Miami, Bermuda, and Puerto Rico. Some researchers have called the area inside those lines the “Devil’s Triangle.” To others it was the “Hoodoo Sea.” The name that seems to have adhered to it best during the past century is the “Bermuda Triangle.” Like all prominent mysteries — from land, sky, sea, or space — the Bermuda Triangle initiates fierce and wide-ranging controversy. To those who are prepared to be totally objective, receptive, and open-minded, it might be a star gate, a doorway to hyper-space, an a
ccess point to unknown dimensions, a time portal, a vestigial remnant of ancient Atlantean technology, or the hiding place of extraterrestrial beings.
To cynics and skeptics — whose views are vital when genuine mysteries are being investigated seriously and scientifically — the area is naturally dangerous, and the hazards there may well include geological and meteorological features that can affect magnetic compasses. The area is always susceptible to sudden and unexpected air turbulence. A plane can be flying smoothly and normally one minute and bouncing around like a tennis ball the next. The weather within and surrounding the Bermuda Triangle is unpredictable. Meteorologists know well that a relatively minor storm can become a deadly, dangerous hurricane if the time, speed, and fetch are all that way inclined. (The fetch indicates the area over which the wind is able to blow uninterruptedly; the other two storm-to-hurricane transformation inducers are the time the storm has to develop and build up its power and the speed with which it’s travelling.) Relatively modest thunderstorms can be transformed in a very short time into what meteorologists call meso-meteorological storms of great power. These small, sudden, violently escalating and very hazardous storms are exacerbated by the meteorological conditions that pertain to the Bermuda Triangle: cold airstreams there encounter hot ones, and they react to each other like rival tomcats establishing their territory. The warm water of the Gulf Stream also cuts across the Bermuda Triangle and contributes to its abnormalities.
Sailors who know the area well report the mysterious electrical phenomena frequently seen on the masts and yards of sailing ships generally referred to as “St. Elmo’s Fire.” Travellers through the Bermuda Triangle also report frequent and dynamic bolts of lightning accompanied by a strange, burnt, ozone-like, hot-metal smell. Ball lightning has also been reported there.