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Salt Water Fish Of The Shallow Water - Sharks, Remoras, and Rays
Perhaps you think any fish that lives in salt water is a deep-sea fish, but you'd be wrong. To the marine biologist, this is not the case. Actually, our better know salt water fishes are known to science as shallow water salt water species.
They come from waters along the shore or roam the seas near the surface. Some of these, to be sure, descend to depths of one or two thousand feet upon occasion. The shallow water types, however, are a group apart from the marine animals that inhabit the abyss, as the deep regions below about six thousand feet are called. Those marine animals of the far depths are unknown to most people.
The shallow sea is by no means a somber place the world over, for in tropical waters there are fish as brightly colored as flowers. They often appear far more splendid as they flash through the sparkling blue water.
The shallow seas are not quiet, either, for fish have several ways of making noises. This was promptly discovered when underwater listening devices were first invented. The sounds fish produced include hissing noises, grunts, snorts, drumming sounds, and many others. Sometimes the sounds are results of throat and air-bladder movements, in other cases they are caused by grinding the teeth together. Still in others, they are produced by the friction of one surface upon another.
Drum fish, for example, are notoriously noisy, and can sometimes be heard through many feet of water by people standing upon decks of ships.
The fishy creatures of the shallow seas fall into two major groups:
- True fishes -- which have a bony skeleton and often an air bladder
- Fish-like-forms -- which have a skeleton of cartilage, not bone, and no air bladder
Sharks, sting rays and their relatives are in the second group, though they are like many true fish in general form and habits.
Sharks - Fierce Wolves Of The Sea
Sharks are denizens of the warm seas, for the most part. They often feed upon fishes in the coastal bays. they are well equipped to capture their victims, for they have several rows of serrated (sharply notched), triangular teeth, like small saws, in each jaw.
The ability of sharks to slash and bite with these vicious teeth has earned them the name of "Sea Wolves." A wounded shark is in immediate jeopardy, for it is likely to be set upon and torn to bits by its fellow sharks. Sharks have their own coat of armor. That is, set into their skin are numberless tiny pointed tooth like structures, replacing scales.
Most species of sharks are less than eight feet in length, and many of the smaller species are not likely to attack human swimmers and divers. However, they do destroy quantities of food fish and drive other fish from the fishing grounds.
For example, the small Dogfish sharks, which attain a length of about two or three feet, are quite a nuisance to fishermen in our coastal waters. They destroy food fishes and often damage nets, slashing the cords with their teeth in frantic struggles to escape (not that you can blame them).
Different Types of Sharks
The Great White Shark of tropical and subtropical seas is one of the larger and more notorious types. It has been reported up to lengths of about forty feet in the old days and now is generally seen around half that size.. It is a man-eater and its appearance in the vicinity of a bathing beach invariably causes excitement and justified alarm.
The Basking Shark exceeds the Great White Shark in size. However, it is not nearly so well known. The fact is that the Basking Shark has small, weak teeth and is poorly equipped to attack large animals. So it is generally not aggressive and feeds upon small marine life near the surface of the sea.
One of the most peculiar looking sharks is the Hammerhead Shark -- one of the most voracious types. Its head actually resembles a hammer in shape, and its eyes protrude far out from the two ends of the "hammer." The Hammerhead grows to be about fifteen feet long. One unique and little known thing about this shark is that it has a special use, because its liver is an exceptionally good source of vitamin A.
As a matter of fact, all sharks have large livers. The liver of a great White Shark may weigh found hundred pounds or more and may contain over forty percent oil. Some of sharks' liver oil, mixed with fish-liver oils are used today for vitamins. Additionally, much sharks' liver oil goes into special foods for poultry and cattle.
The sharks, for all their aggressiveness, can be imposed upon. This is done by a group of rather small bony fishes called Remoras." A Remora has one of its back fins modified as sort of a sucker, with which it can cling to the body of a shark. Sometimes several Remoras will be attacked to a single host animal. So to speak, the Remoras "go along for the ride." Remoras also attach themselves to other large marine animals, including turtles and even whales.
When a Remora has hitchhiked into the vicinity of a likely school of small fish, it detaches itself and pursues the small fish vigorously. After it has eaten its fill, the Remora seeks another large marine animals that will serve as its means of locomotion.
In some parts of the world men have learned to use Remoras in fishing. They fasten a Remora to a line and allow it to swim about in the water. If it has an opportunity, it will promptly attach itself to a larger fish. Then both fish can be hauled in together.
Rays are relatives of the sharks, though at first glance they look very different. The ray's body is flat as a pancake. However, in other respects the ray is quite shark like.
Rays often lie at or near the bottom in shallow water. Swimmers have stepped upon sting rays to their sorrow, for a ray's long slender tail bears a barbed spine and when the tail is lashed back and forth this spine can inflict a painful wound, and of course rarely cause death. None of us are likely to forget this if we were fans of Steve Irwin.
Torpedo (Electric) Rays
Torpedo or Electric Rays include some big fellows which may attain weights of one hundred pounds. Located near the head region are two groups of cells which make up the so-called electric organs. Similar electric organs are possessed by some eels and catfishes. About these organs there was once a great bit of mystery and scientific controversy in the past.
The largest of this species, the Atlantic torpedo ray can actually produce a 220 volt electric shock, which is pretty impressive.
It is believed that these electric rays have muscle cells (electroplaques) that produce an "electric organ" that allows the marine animal to store up like a battery, electricity in these tissues. At will, or when frightened, the ray can shock prey or repel a predator.
This is still an area of great research among scientists, because their tissue has such unusual properties and may be of use in the neurological field in terms of medical research.
If You'd Like To Know More!
- Florida Museum of Natural History Ichthyology Department: Pacific Electric Ray
Florida Museum of Natural History Ichthyology Department homepage. This page contains, educational sections about the biology, ecology and conservation of fishes and sharks. A rich photo gallery features the work of world-renowned underwater photogra
- Hammerhead Shark
Information about Hammerhead Sharks and their life beneath the sea.
- Marbled Torpedo Ray aka Marbled Electric Ray information and pictures.
- SDNHM - Remora remora (Suckerfish or Remora)
Description of Remora remora (Suckerfish or Remora).
- Marine Biology - Hammerhead Shark
- THE REMORAS OR SHARK SUCKERS. FAMILY ECHENEIDAE