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*MARINE VERTEBRATES These share 3 fundamental characteristics, backbone, which enclose the nerve cord, and bilaterally symmetry and a presence of an endoskeleton.

THE FISH

There are over 22,000 species of fish which make up more than half of all vertebrate species and most (58%) are marine.

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*Jawless fish, Agnatha, first appeared about 550 million years ago. They occupied the worlds rivers and seas and lived unchanged for about 100 million years until 2 revolutionary developments occurred, namely biting jaws which developed from the front gill arches and fins became paired.

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*These enabled fish to be able to eat a variety of foods and swim better. The jawless fish population declined after this. Chondrichthyes evolved before bony fish. These cartilaginous fish had a ventral mouth and a skeleton made of cartilage. The bony fish had a true bone skeleton, specialized mouth, and a swim bladder.

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*In 1938, off the coast of South Africa, near the Chalumna River, a fisherman brought up a strange fish. It weighed a hundred pounds and was 4 feet long. The body was covered with circular scales and when it was identified by Prof. JBL Smith, it was found to be a living member of an ancient class of fish that was thought to have gone extinct 70 million years ago.

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*It was the Coelacanth, the oldest true fish.

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*The body forms of the fish are adaptations to the environment or special behavior patterns.

The streamlined or fusiform shaped fish allow rapid movement through the water ad are found in predatory fish.

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•Fish compressed from side to side can easily move through plants and in narrow spaces.

•Flattened dorso-ventrally, depressed, are usually bottom dwellers.

Attenuated...elongated eels live in sand, mud or under rocks.

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*Fins aid in locomotion. The dorsal and anal fin are used as rudders to prevent rolling, paired pectoral and pelvic fins are used in turning, balancing, and braking. The caudal or tail fin is used mostly for pushing against the water.

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*In sharks, and other cartilaginous fish, the fins play a role to stop the fish from sinking because of the lack of an air bladder.

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*Three types of fins are found on the tail, heterocercal, the top is taller than the bottom of the fin, homocercal, both top and bottom of tail are the same... symmetrical, and diphycercal, the tail ends in a point.

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*The mouth of a fish and its teeth are adapted for the type of feeding the fish carries out. There are 5 types of feeding methods:

1. predators, specialized teeth for grasping and chewing,

2. nibblers, take small bites,

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*3. food strainers, use of gill rakers to strain the food floating in the currents,

4. food suckers, bottom feeders who draw food through the mouth like a vacuum cleaner and

5. parasites, attach to another fish and live off its juices. (Candiru or Vampire Fish)

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*Fish have a one way digestive system. Food enters the mouth and passed to the pharynx where it is funneled to the esophagus. In parrot fish, sucker fish, etc. the pharynx is equipped with teeth that grind, grasp and tear the food before it enters the esophagus.

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*Puffers, globefish, porcupine fish can pump water into their stomachs to inflate themselves.

Parrot fish, pipefish, and seahorses don't have stomachs and digestion and absorption take place in the intestine.

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*Food passes from the stomach to the intestine where chemical digestion continues and the end products are absorbed. The intestine is folded, coiled and spiraled to increase surface area. Meat eaters have shorter intestines than plant eaters. Nutrients absorbed enter the blood and are transported to various parts of the fish by the circulatory system.

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*Circulation

Blood is pumped from the heart to gills where gas exchange takes place. Blood carries oxygen via red blood cells to all parts of the body, transports CO2, digested food, wastes etc. and returns to the two chambered heart. The heart has one atria and one ventricle

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*Respiration

Most fish obtain oxygen directly from seawater using a gill. Water is taken in through the mouth and pumped over the gills. The gill is located behind the mouth in the gill chamber and consists of several gill arches. Each gill arch supports many gill rakers and gill filaments.

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* Dissolved O2 diffuses across the thin membranes of the gill and enters the blood. The gill rakers are positioned to stop particles suspended in water from damaging the filaments. Water pumped past the gill leaves the gill chamber through the gill slit. The gill slits in bony fish are covered with an operculum.

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*Jawless and cartilaginous fish have open gill slits. Sharks and rays have a modified gill slit, the spiracle which works with the mouth to bring water into the gill chambers. It is found on the dorsal surface of rays.

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*Gas Exchange

Thin membranes of gill filaments make gas exchange easy. Diffusion occurs and O2 is picked up by the blood. Diffusion is increased by two features,

1.-surface of gill filaments increased by branching increasing area of membranes which come in contact with water and

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*2.-water flowing over gills move in opposite direction of blood movement in the gills. This counter current system enables blood to pick up a maximum amount of O2 from the surrounding water. Adaptations include: carp gulping air which can diffuse into the gill filaments, lungfish with air sacs, enlargements of the gill chamber etc.

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*Buoyancy

Fish with well-developed swim bladders can remain poised at a desired level with minimum effort by increasing or decreasing the amount of gas in the bladder. The bladder can be filled by gulping air or release of gas from the blood through gas glands.

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*When the fish goes deeper, the increased pressure squeezes gas in the bladder, decreasing gas volume of the bladder. The fish becomes heavier/denser.

The fish restores gas volume by secreting gas from the blood. As the fish moves up, there is less pressure on the bladder, and the gas expands.

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*The fish becomes lighter and more buoyant so in order to prevent the bladder from overfilling, the fish must reabsorb the gas. Fish with an air-tube connecting the bladder to the digestive tract can let gas escape through the mouth, (open swim bladder) but a closed swim bladder system, reabsorption is necessary.

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* If a fish was pulled up from deep water quickly, its swim bladder could explode! Vertical movement is limited by the swim bladder...predators like sharks, don't have to worry about that because they have no swim bladder.

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*Temperature

Temperature has a profound effect on metabolism of fish because most are cold-blooded (ectothermic). Generally a rise in temperature speeds up the metabolism and a drop slows down metabolism and reduces swimming speed etc.

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*Most fish generate heat but lose it rapidly to the surroundings because they lack insulation. Predatory fish have evolved a countercurrent system for conserving heat and muscles can stay warm with energy producing reactions.

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*Excretion.....Disposal of wastes produced during metabolism

Bony fish have salt secreting cells in the gills called chloride cells that remove excess salt.

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*Sight

Like the human eye in some ways but the density difference between the water and cornea of the eye is not so great so the lens of the fish is hard, dense and round to maximize refraction. Light is focused by moving away or toward the retina.

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*The eyes bulge out with the lens protruding through the pupil. Iris is not adjustable. Color vision is developed in fish mainly in shallow clear water helping locate food, breeding partners and avoiding predators. The eyes are on either side of the head increasing the visual field which helps for animals with no neck!

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*Hearing and Balance

Ears, lateral line organs and swim bladders aid in detecting underwater sounds, maintaining balance and enabling some fish to produce sounds. The inner ear, labyrinth, functions for hearing and balance. Fluid filled canals and receptor cells, neuromast sense cells are sensitive to movement in fish.

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*It bends and pushes ciliary hairs of the neuromast sense cells and the impulse is sent to the auditory nerve to the brain. Ear stones, otoliths, move in the tubes in conjunction with fish movements, shifting positions,and this helps with the balance and hearing.

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*The neuromast cells are also found in the lateral line organ, detecting low frequency vibrations. The swim bladder vibrates as sounds in water pass through the fish. These vibrations are passed to the inner ear. The toad fish generates sounds in this way.

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*Smell...chemoreception

Detection of dissolved substances in water is how the fish can smell its food. Taste buds in the mouth taste the food, barbels, whisker-like appendages, contain taste buds which enable the fish to probe muddy waters

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*Electroperception

The ability of fish to detect weak electrical currents in water/or generate them. This is used for communication and examining the environment. Some can discharge several hundred volts, stunning its prey and easily capturing them to eat.

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*Cartilaginous fish have sense organs in the head called the ampullae of Lorenzini that can detect weak electrical fields. It is used to help locate their prey, assist in navigation and maybe even detect currents.

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*Outer Covering

The entire skin of the fish is alive, even the scales are covered by a thin layer of living cells, the epidermis the only protective material covering the epidermis is slime secreted by mucus glands scattered over the body

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*The mucus reduces friction and protects against bacteria etc. Fish odor or body odor is found in the slimy covering. This allows fish to recognize their species.

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Scales form a protective outer covering. There are 4 types of fish scales. Sharks and their cartilaginous relatives possess tooth-like Placoid scales.

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*Platelike Ganoid scales made of bone are found on primitive fish like the gar pike and sturgeon.

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Cycloid and Ctenoid scales form an overlapping covering like roof shingles on a house. The scales are thin and flexible allowing great mobility. Cycloid scales are mainly found on soft-ray fish and ctenoid scales are mostly found on spiny ray fish.

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*Coloration

This serves in functions like camouflage, looking for a mate, advertising the fact its poisonous or showing willingness to remove parasites. Two types of cells control color namely Chromatophores and Iridocytes.

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*Chromatophores are starshaped pigment cells located under transparent scales or in the thin cell layer overlying the scales. The nervous system and endocrine system seem to control the redistribution of pigments within the chromatophore. Iridocytes are pigment cells containing reflecting granules (work like mirrors).

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*The silvery stripes and iridescence of some fish result from light being reflected by iridocytes. There is warning coloration, cryptic coloration (blend), disruptive coloration, and countershading.

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*Defense and Migration

Fish that don't swim well have evolved protective devices. Some include the sharp spines of the surgeon fish and trigger fish or the protective armor of the trunk fish, seahorse and pipefish. Seahorses have a prehensile tail which they use to hold on to underwater branches and remain motionless

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*Globefish and puffers expand their bodies by pumping water into their stomachs. Coloration...countershading is where the dorsal side is darker than the ventral side making the fish difficult to see. The clownfish has contrasting colors to deceive the predator (disruptive contrast).

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*Secretions...unicorn fish expels a cloud of ink, and stonefish and scorpion fish possess poison glands.

Schooling fish apparently have a decided advantage over non-schooling fish.

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*Migration

There are two reasons for seasonal migration. 1. food and 2.breeding. Migratory fish travel thousands of miles to return to the same place each year. If they breed in fresh water they are anadromous and if they breed in salt water they are catadromous.

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*A third type remain in the ocean and move on definite pathways between feeding and breeding areas. The ocean wanderings of migratory fish correspond to ocean currents

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*Reproduction and life history

Many ways have evolved for marine fish to reproduce.The sexes are usually separate and both sexes have paired gonads located in the body cavity. In most marine fish, the gonads produce gametes only during certain periods of time. This is crucial because both sexes need to be ready at the same time...especially in those that migrate to breed.

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*The timing is controlled by sex hormones which are released into the blood to stimulate the production of gametes. They are released by being triggered by environmental factors like temperature, light, and food availability.

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*Some fish are hermaphrodites and though able to fertilize themselves they usually breed with other individuals to ensure fertilization between species. This is also common in deep water fish as an adaptation to the dark depths and the chance of NOT finding another fish of the opposite sex.

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*Sex reversal also occurs in some fish. Individuals begin life as males but eventually change into female or vice versa.

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*Fertilization in fish is usually external but in some cases, internal fertilization happens. Different types of development of the egg occurs. Usually external fertilization involves the production of many, I mean many, eggs. They end up floating in the plankton and most don't survive. This is OVIPAROUS, or the egg develops outside the body and feeds off the yolk

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*Some fish, mainly cartilaginous ones, have eggs that develop inside the body and the young are born alive. This is OVOVIVIPAROUS. Some rock fish have this method of reproduction.

In some sharks and rays, the embryos actually feed off nutrients of the mother. This is like mammals and is known as VIVIPAROUS.

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Lampreys.. eel-like and has one or two dorsal fins a caudal fin and no paired fins. The mouth, jawless, is a disk adapted for sucking, with a complex arrangement of teeth, their arrangement specific to the species and therefore used in classification (Agnatha-2 classes, 1 order each, Lampreys have 3 families with a total of 72 species

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*Hag fish or slime eels are eel like have a fleshy fin, and flattened caudal region. They have 4 to 6 tentacles around the mouth. No jaws or stomach but are parasites of larger fish and defend themselves by releasing slime

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*Sturgeons are the largest and longest lived freshwater fish and provide food! Caviar! The sturgeon and paddle fish are the only survivors of an ancient group of fish. They migrate to and from the sea.Sizes are impressive...1800lbs,

Bowfin and Garfish...bowfin can survive out of water using their air bladder as a lung.

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* Garfish, long bodied predators long jaws and many teeth and armor like scales.

Tarpons, Eels, Notacanths...weird that these unalike fish are grouped together but all have larva unlike the adult.

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*Bristlemouths...luminous organs, bristle like teeth eyes on stalks

Lizard fish and Lantern fish...sit on pelvic fin and lower tail lobe

Spiny finned fish latest flowering of bony fish evolution.

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*Billfish

The term billfish encompasses two closely related families, the Istiophoridae: sailfish, spearfish, and marlins and the Xiphiidae, the swordfish.

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*The term billfish is usually reserved for the istiophorids and call the only member of the family Xiphiidae, a swordfish. Both families of fish have members whose upper jaw is extremely elongated and narrow. These are all fast-swimming, aggressive fish in the open ocean with a tall dorsal fin and lunate (quarter moon shaped) tail.

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*They have a unique circulatory system that keeps the warmth generated by their active swimming retained in the muscles. This makes their muscles slightly warmer than the surrounding water and gives them an advantage over the slower-moving, completely cold-blooded fishes.

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*Most are tropical and subtropical in distribution but are often caught in temperate waters, especially in summer months.

They are among the oceans fastest swimmers. Sailfish have been clocked at a minimum of 70 MPH for short bursts and probably cruise at 20 to 30 MPH. The long bill is thought to be a cutwater which aids these fish in very fast swimming.

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*It is also used to decimate schools of fish by thrashing it back and forth horizontally through the water and is thought to be used in "battles" with other bill fish. The lunate tail and narrow, keeled peduncle (area just before the tail) are also adaptations for fast swimming.

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*Even the dorsal and pelvic fins of the sailfish fit into neat grooves on the body to prevent any unwanted drag. Although marlin may be somewhat slower than sailfish, and swordfish slower yet, "slower" in this case is still close to 40-50 MPH.

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*There are eleven species of billfishes and swordfish, five of which are found in the Gulf of Mexico. The term includes two fish families, which inhabit tropical and sub-tropical oceans worldwide.

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*The family Istiophoridae contains ten members: the marlins (genus Makaira), the spear fishes and white marlins (genus Tetrapturus), and the sailfishes (genus Istiophorus). The swordfish, Xiphias gladius, is the only member of the family Xiphiidae.

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*Swordfish can easily be distinguished from the istiophorids. The sword or bill of the swordfish is a broad flat blade making up about one-third of the body length. In addition, the fish lacks pelvic fins, and in the adult, teeth and scales.

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*Although all billfish are large, (at least 5 feet), the two edible species outdo themselves. Both marlins and swordfish are taken at lengths of 6 to 15 feet and 300 lbs to 1000 lbs.

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*They undergo long distance migrations and range far afield for their food. One fish, tagged off the Virgin Islands, was caught four months later 4,500 miles away off the coast of West Africa.

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•Young fish less than an inch in length, may take refuge from predators under floating Sargassum or sea grass. Here they prey on smaller, less active fish who are also seeking safe harbor

•Adult billfish eat a wide variety of fish: flying fish, scad, mullet, round herring, ballyhoo, mackerel, tuna, and jacks.

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*They also eat squids and other billfish. Only humans and mackerel sharks, killer whales and bigger billfish eat billfish.

The bill can be used in aggressive encounters with other billfish as evidence of billfish caught with pieces of bill embedded in their bodies. Whales have also been attacked by billfish.

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*Catch them on hook and line, baited with live mullet, mackerel or squid though the numbers are dropping rapidly.

Large marlin are always females. Whether males change sex as they attain greater size and become females or just stop growing as fast as the females is presently being studied. Small specimens of males and females are found its just only females are the record catches!

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*Sharks.

Over 350 million yrs ago, something new happened in the primeval seas...an entirely new class of vertebrates evolved which were quite different from anything before. They had tiny tooth-like body armor called placoid scales, exposed strap-like gill openings, unique paired copulatory organs and flexible skeletons of cartilage

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*These groups settled on a lifestyle that has persisted to the present. They are slow growing, late maturing, produce small numbers of well formed young of whom a mother invests a lot of resources during development but virtually nothing after the young are born.

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*Most people think sharks are large, fast swimming elegant savage predators. This is true of some species but only a minority. The group should be of general interest because of the intriguing aspects of biology found in sharks, the exceptional sense of smell, electropreception, and giving birth to live young.

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**One notable feature is its teeth. In the highly predaceous sharks, these are large and razor sharp used for cutting and shredding their prey into bite size pieces. Some however are bottom feeding species and eat mollusks and crustaceans and their teeth are flattened for crushing the shells of their prey. The fish eaters have long thin teeth to help catch and hold their prey..

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*A shark may have up to 3000 teeth arranged in 6 to 20 rows according to the species. In most sharks only the first row or two are actively used for feeding. The remaining rows are used for holding prey. They are in various stages of formation with the newest at the back.

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*As a tooth in the functioning row breaks or is worn down, it falls out and a replacement tooth moves forward in a sort of conveyor belt system. They can be replaced every few days. This keeps the functional row sharp. The shark may use over 20,000 teeth in a lifetime and the strength of the jaws can exert a biting strength of 3000kg per sq. cm. (44000 lb/sq. in. on the teeth. (humans are 150lbs).

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*Sharks find their prey through a number of sensory systems. Many have poor eyesight but some are real good. Some have barbels around their mouth to taste the sea bed for prey. All sharks have a very keen sense of smell. Their nostrils are used only for smelling, not for breathing. The part of the sharks brain that deals with smelling is twice as large as the rest of the brain.

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*Sharks can detect 1 part of blood per million parts of seawater (1 drop in 25 gal). They have a lateral line system which is a series of canals on the entire body and head which are filled with a jelly-like substance, which are sensory receptors which pick up pressure waves caused by movements of other animals or even by the shark itself.

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*On the snout are ampullae of Lorenzini, a series of electro-receptive pits which are the most sensitive electro-perceptive devices found in any animal. They are capable of picking up one-millionth of a volt, which is less than the electric charge produced by nerves in an animals body. The sharks can find their prey from the prey's natural electric output.

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*Sharks..The six and seven gilled sharks have extra sets of gills preferring cold water some being filmed at 1800m. The orectoloboids are five closely related families of sharks ranging from 3'long to the whale shark 50' long.

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*All but the whale shark are bottom dwellers and spend most of their time just sitting on the ocean floor and actually skeletons modified so they can actually use their fins for walking on the ocean floor. They have sensory barbels around their mouth

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*The whale shark has gill arches specially modified to act like a sieve to filter out the planktonic organisms upon which it feeds. Because it of its bulk it needs constant fuel and feeds as it swims.

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*The thresher, mackerel are among the largest group of sharks in the world. They have a long upper lobe on their caudal fin and use it by swimming through a school of small fish, thrashing the tail and killing or stunning the fish which are then eaten.

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*The family of mackerel sharks include the great white, mako and basking sharks. Their caudal fins have lobes being nearly equal in length. Most if not all are homothermic which means they can keep their body temperature above that of their surroundings. The Mako is probably the fastest, measured at 60mph and is known to have out swum and eaten swordfish.

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*The great white/white death/white pointer etc. mainly feeds on marine mammals, the only shark to do so, and has broad serrated teeth designed for biting large chunk of flesh from whales and seals. It is viviparous, meaning the embryos develop in the uterus. The basking shark is another filter feeder and the second largest in size...45'.

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*The requiem sharks, are the typical sharks, the bull shark, which can enter freshwater and has been found more than a thousand miles from the mouth of large rivers. The largest is the Tiger shark..18' and the most dangerous. It swallows almost anything, including roles of tar paper, shoes, gas cans, license plates, cans of paint and human parts

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*Hammerhead sharks, also in this group, have large lateral expansions of their head on which the eyes are set. They grow to 15' and the expanse of the head gives a better field of vision, and a more expansive electro-detecting system.

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*Shark Reproduction

Success is due to the reproductive adaptations. Males have claspers which release sperm into the cloaca. Young are born as miniatures of the adults and few in number. Their large size reduces predators and allow for more nutrients for the young. Eggs are produced with large yolks.

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*3 types of egg laying:

1. ovipariy- egg laying...bull head, some nurse sharks

2. ovovivipary- thin shelled eggs hatching in the uterus before full development. No placental development, use yolk. Tiger, dogfish.

3. Vivipary-no shells-some yolk but mostly nourished by mother through the placenta. Bull, lemon, hammerhead, great white.

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*Skates Rays and Chimaeras.

Examples are the eagle rays, electric rays, guitar fish, mantas, sawfish, skates, stingrays, and the chimaeras. There are about 300 species of rays and skates which have flattened bodies and live usually on the bottom (Demersal).

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*There are some rays that look like sharks and some sharks with flattened bodies so the way to tell is that the skates and rays all have heir gill slits on the ventral surface. The enlarged pectoral fins are fused to the head and the eyes are on top of the head.

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*The stingrays have a whiplike tail usually equipped with spines for defense. Poison glands produce venom. Skates are like rays but lack a whiplike tail and stinging spines. Some can have electric organs .

Rat Fish ..about 25 species of this deep water chimaera, is separated because the gill slits are covered by a flap of skin. The long tail gives it the name "ratfish".

• A modern Tarpon fishing method that has surfaced recently is to sight fish these creatures which can be really rewarding. Tarpon can be found rolling and feeding on the surface throughout Charlotte Harbor. Live bait and artificial are the weapons of choice here. These fish are feeding in 5-15 foot of water and when hooked on the end of your line become explosive. Tackle is 25-30lb gear with 100lb leader and 7/0 hook for live bait or a variety of plugs and/or flies for the Fly-Guys.

• There are no crowds to contend with and if there is another boat in the area he's probably your buddy. This gives you the room for unforgettable action allowing ample space and time to fight even the biggest of Tarpon. On a typical day you can easily jump 10 Tarpon fishing, and perhaps boat 2 or 3. But one thing for sure it beats fighting a crowd and makes a trip a lot more memorable, And the scenery in Charlotte Harbor is magnificent.

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Vicious Fishes and their Friends!

.The icthys or fish symbol has been a sign of peace for 2000 years. Most fishes cooperate and live up to the stereotype - they are peace loving, at least where humans are concerned. Being instinctively man-shy helps finfish survive in a hostile world full of hooks, nets and spears.

But some fishes contradict the peaceful image, having impressive weaponry of their own.

. These devils are well equipped for defense; under the wrong circumstances they will even attack careless or ignorant intruders. Science has come up with a specific antidote for the venom of only one of these beasts -the stonefish. Results of contact with such fishes include brief discomfort, excruciating pain, and death.

. Our goal here isn't to scare you - just to make you aware of what may lurk beneath the waves, and what you can do to protect yourself.

Sharks, of course, are a well-known group of fishes that sometimes harm surfers. There are quite a few other finfish that can deal out misery. Some make their homes on the edges of surfing's frontiers --the remote tropical areas where waves are

. abundant and uncrowded, but where medical care is sketchy or nonexistent. Others are right beneath you in heavily surfed parts of Australia, Hawaii, Mexico, the Caribbean and Europe. What you don't know can hurt you. It's worth knowing what the worst and most common of these guys look like, where

they hang out, how to avoid them, and as a last resort how to deal with the damage they inflict.

. S T I N G R A Y

Stingrays are related to sharks and are feared not for their bite but for the painful sting they can inflict. They account for most of the injuries caused by all venomous fish. Because stingrays often lie half-buried in the sand, most injuries occur when an unwary diver or swimmer accidentally steps on one.

. SPINE: The ray's sharp spine is located at the end of a whip-like tail; it can inject venom, causing excruciating pain and even death.

VENOM: The venom affects the victim's cardiovascular system, causing loss of blood pressure and a rapid heartbeat.

. CAMOUFLAGE: When lying on the ocean bottom buried in sand, stingrays are almost impossible to detect.

TAIL: The ray's tail can lash in all directions, increasing its chances of inflicting a wound.

PREDATOR: sharks PREY: molluscs, decaying matter

. STINGRAYS

live on sandy bottoms^,

in temperate and tropical seas around

the world. The body shape is triangular with a long, whiplike tail bearing one or more barbed spines. Stingrays come in colors and patterns that blend with their surroundings.

.How they get you: Stingrays bury be themselves in sand with their large, winglike pectoral fins. If you step on one you will make it mad, and your weight will give it the leverage it needs to whip its spine into your ankle or calf – which it can do very accurately. Symptoms; Lacerations, severe pain. The spines are sharp at the tip for good penetration, but barbed along the sides for difficult removal.

. This trashes nearby tissues and gives venom a better chance to ooze in. By the way, stingrays get big.

One Aussie had a ten-foot specimen

drove a spine right through his leg,

making a 4" gash on the far side.

. Treatment: (Study this section well;methods for treating stingray wounds basically apply to any fish sting.)

Time is a critical factor. If emergency medical help is available nearby, by all means go for it, and quickly. If not, you're on your own. Immediately irrigate the wound well with cold seawater. Carefully explore for any pieces of the spine's wrapper.

.This is the venom secreting tissue, and all of it should be removed.

Cleanse thoroughly and soak the injured area in water as hot as the victim can stand for 1/2 to 1¹/2 hours. Primary shock may set in (nausea, faintness, vertigo); treat this with encouragement of the, "you'll be all right" variety. Opiates are effective against the pain. Do not use ice or ammonia.

. The hot soak complete, check once more for foreign matter. If the wound is large, get the victim to medical help as soon as possible for sutures; if it is small and looks as though it will close up by itself, elevate the injured area, apply antibiotic ointment, keep it clean and dry, and update tetanus as necessary.

. Prevention: Always shuffle your feet when wading an muddy or sandy bottoms in unfamiliar territory. Abdominal, head or neck stings are very serious, so avoid swimming and horsing around in the shallows.

. L I 0 N F I S H

The lionfish is a beautiful and ornate reef fish. Lionfish are typically found moving slowly, fearlessly, and majestically through warm, shallow reef waters. They are also called turkey fish because they spread their fanlike pectoral fins much like turkeys spread their plumage.

. SPINES: Hidden in the attractive fins are 13 dorsal spines, 3 anal spines, and 2 pelvic spines. At the top of these sharp thin spines are glands which produce venom.

VENOM: The venom of the lionfish causes an immediate, sharp, intense, and throbbing pain. The pain usually lasts a few days, although some species carry a stronger venom in their spines.

. ^-ZEBRAFISH Alias turkeyfish, liontish, featherfish,tirefish (USA), Man bambou (Indonesia)

Once you've seen oneyou ‘ll never forget it. They seem to love to

show off their long, lacy, feathery-looking fins - which are well armed with venomous spines. The color combo is maroon, black and white. Anything but shy, these guys like to cruise open shallow water near rock or reef crevices, often in pairs.

. How they get you: These gorgeous, fearless little fishes are tempting for the naive snorkeler or wader, new to the tropics, to touch or approach. Don't! Zebrafish venom is quite potent, and they are good at aiming and jabbing with the spines concealed in their fins. Unlike their close relatives, the stonefish and scorpionfish, zebrafish are so brilliantly colored and distinctive that they are easy to avoid - once you know they're venomous.

. Symptoms: Immediate, intense pain, which may last for several hours. Tissues around the wound may disintegrate and gangrene may set in, especially after inadequate treatment. Heart attacks, delirium, convulsions and death have been reported.

Treatment: Get medical help if possible. Otherwise treat as with stingray stings, again encouraging bleeding to flush venom out of punctures.

. Opiates may or may not be of any use against the pain.

.Puffer Fish

Puffers and blow fish are so named because of their ability to inflate their bodies when threatened by predators.

They are the most poisonous marine fish to eat because of the deadly toxin contained in parts of their internal organs.

. The poison (tetrodotoxin) is so powerful and quick-acting that death can occur within 15 minutes after the fish has been eaten. There is no know antidote. Victims of puffer fish poisoning experience extreme pain and complete paralysis.

.Triggerfish

The colorful triggerfish is found in coral reefs. It gets its name from the spine located on its dorsal side. This spine can be extended like a jack-knife, and the triggerfish uses it to lock itself into crevices where it can hide.

. The triggerfish uses its sharp teeth to break off the spines of the sea urchin, its favorite food. One species, the ocean triggerfish, is known as the "piranha of the reef" because it has been known to use its sharp teeth to attack divers.

. TEETH: The triggerfish is dangerous because of its teeth, and it can be poisonous to eat. While the meat of the triggerfish itself is not poisonous, the triggerfish feeds on substances that they make it poisonous when eaten. This is called ciguatera poisoning.

. SURGEONFISH

Alias tang, doctorfish (USA); kaia,

rnanini, paksimk/ (Hawaii); labahita (Philippines), vana ki (Indonesia) are very common reef fishes throughout the, tropics. They have high foreheads, hang out in schools, and come in many beautiful colors, even within the species. This fish gets its name and nasty reputation from the sharp, hard blades which it can erect on both sides of the narrow part of the tail.

. When at rest, the blade lies in a groove which is lined with venom glands; it is constantly bathed in venom and ready for action. The dorsal spines (down the center of the back) are also venomous.

How they get you: 1: Wading through shallow water containing lots of surgeonfish.

. When alarmed they whip out their blades and go into a slashing frenzy. causing deep, painful cuts in whomever's flesh is handy.

2: Removing a surgeonfish from a net or spear.

Symptoms: treatment: Pain,

secondary infection. Treat as with stingray attack.

E L E C T R I C E E L

The electric eel, a river dweller, can generate more than 650 volts of electricity.

Scientists have pondered over the electric eel's ability to generate such power and after a century of research they still do not completely understand the process. They do know that the electric organs consist of several electroplates and the discharge is

. controlled by nerves in the spinal cord.

SIZE: These fish can grow to a length of 9 feet. The electric organs take up four-fifths of the entire body.

. ELECTRIC SHOCK: When searching for prey, the eel emits weak discharges of about 40-50 volts in order to locate its food. A more powerful discharge is emitted to stun prey.

. Because water conducts electricity extremely well, a strong discharge could stun a horse in the water nearby. Repeated shocks could render a person in the water completely helpless and thereby cause drowning.

. ELECTRIC EEL

Electric eels are not true eels, they are only eel-like in shape. Electrophorus electricus is famous for its ability to produce strong
electrical currents, reaching 500-650 volts. This strong discharge is used to stun or kill prey. This electrical discharge is also used to ward off potential predators.

. Up to 6,000 electroplates are arranged like a dry cell in the eel's body. Its internal organs are all in a small area behind the head, with 7/8 of the eel being tail. The electrical shocks come from muscles mainly in the tail portion of the electric eel's body. The body of an electric eel is similar to a battery. The tail end of the eel has a positive charge and the head region is negatively charged.

When the eel touches its tail and head to other animals it sends electric shocks through their bodies. When the eel is at rest, there is no generation of electrical impulses.

Species: Electrophorus electricus

SIZE:

Electric eels can grow to be 6-9 feet in length.

Voltage potentials recorded from different electric rays vary tremendously, having been measured at as little as 8 to 37 volts (narcinids) up to 220 volts (in the torpedinid Torpedo nobiliana). The result is a jolt of electricity ranging from moderately tingly to stunningly powerful. In some forms, the shock is directed upward - where it may serve to deter would-be predators -

and in others downward - where it may be used to incapacitate prey.

. NEEDLEFISH

Alias aha'aha, auau in Hawaii, where they are plentiful, aren't venomous, but at least one death by needlefish puncture has been reported. As the name implies this is a long, thin silvery fish up to 6' long with a sharp pointed beak. They like it near shore and near the surface.

. How they get you: Needlefish are very swift swimmers. Either by accident or because it thinks surfer, trunks or board is needlefish food, the beast will ram its beak into these targets. My friend David was surfing Hanalei when he was gored by a needlefish; he says it slammed into him like a freight train. The locals gave him a hard time when he started yelling "shark!" "That's just aha'aha, stupid

haole!" David says it hurt like hell, even if it wasn't a shark.

Symptoms: Puncture wound, often with chunks of fish beak broken off under the skin.

Treatment: Simple puncture: so encourage bleeding, disinfect by an irrigating with alcohol or peroxide, apply its antibiotic ointment, update tetanus as an necessary. Imbedded fragments: get an medical help for removal.

. ORIENTAL STRIPED CATFISH

Alias gigi (Japan), barber (S. Africa), ikan sembilang (Indonesia), patuna (Philippines) are pleasant-looking marine catfish native to the entire Indo-Pacific region; they are also one of the most dangerous fishes in the ocean. Young ones are black with two or three lengthwise yellow stripes; the stripes fade in adults, which reach 3' in length.

. ***How* they get *you:*** These fishes love rivermouths and shallow bays – also good spots for waves: they move around

in large schools which, water clarity

permitting, appear as dark roundish

shapes which revolve slowly. A surfer could easily paddle or wade through one of these "fish balls" and get lanced by venomous dorsal and pectoral spines.

. Symptoms: Violent pain, lasting 48 hours or more. Areas around stings turn white, then bluish, finally red. Improperly treated stings turn gangrenous; even properly treated wounds take weeks to heal.

One victim was stung on the thumb: he couldn't use it for 5¹/2 months.

. Treatment and Prevention: Treat as with stingray stings, but encourage bleeding to flush venom out of puncture wounds.

Obviously, leave these fishes strictly alone.

SCORPIONFISH

(Hawaii), waspfish (Australia), rascacio (Caribbean), hogfish, sea scorpion (England), are masters of disguise. Native to most temperate and tropical seas, with the more venomous kinds in the tropics, they have an uncanny ability to blend with their surroundings. A famous and excellent surf spot

. (Padang Padang, Java) gets its name from these beasts. They range from an inch or two to 3 or 4' long, and have venomous spines on their backs and gill covers: they look like fish-shaped rocks.

How they get you: Scorpionfish are

basically passive: you could step on or brush against one while picking your

way over submerged rocks or reefs.

. You could also catch one in a net or on hook-and-line: serious wounds have resulted from handling dead specimen.

Stay off reefs; avoid handling all spiny fishes; steer clear especially of their dorsal spines.

Symptoms: Immediate, intense,
throbbing pain lasting several hours;
swelling, reddening and hardening of rapid pulse.

. Treatment: Get emergency medical

right away, it possible Otherwise, encourage bleeding to help remove venom; clean thoroughly and hot-soak

as for stingray stings. Again, opiates may or may not be effective against !he pain.

. S T O N E F I S H

The stonefish is considered the world's deadliest venomous fish. This sluggish, slow moving fish resembles a stone or chunk of coral and

can inject venom into the unlucky individual who happens to step on it.

. CAMOUFLAGE: The stonefish blends in well with coral and rocks and is very easily mistaken for a rock

Spines: Thirteen sharp spines resembling hypodermic needles are located on the back. The spines are strong enough to puncture the thick rubber sole of a tennis shoe.

. VENOM: The stonefish's venom is a neurotoxin which is deadly as cobra venom and causes rapid pain and swelling. Death can occur with two hours.

. STONEFISH

Alias warty-ghoul (Australia), ikan-satan (Indonesia), tupu (Philippines), are one of the most venomous fishes around -and certainly the ugliest! They look like slimy, crud-encrusted rocks with wide frowning mouths. They are related to scorpionfish, but their venom is quite a bit more severe. They occur only in the Australasian area, reaching a foot or so in length.

. How they get you: Stonefish are even more passive than scorpionfish, and even better at camouflage. They won’t chase you; they will sting only if stepped on or otherwise provoked. Avoid all contact with the bottom if stonefish are uspected in the neighborhood.

Symptoms:treatment:

Excruciating, violent pain, soon involving a large area around the sting.

. Victims may be in such agony that they will flail about on the ground screaming, or simply pass out. Radical swelling, breathing difficulty and death may occur. In minor cases, swelling and painlast for months; abscesses, ulcers, and gangrene may set in.

Obviously, to be stung by a stonefish is an extremely serious injury and should get prompt, intensive medical care. If this is totally impossible, treat as with stingray stings…AND

. Hope like hell that your traveling 1^st aid kit has emetine hydrochloride or stonefish antivenin…..Inject it directly into the wound!

. WEEVERFISH

Alias dragonfish (England), aragna (France ), arana (Spain), aranhuco (Portugal), are one of the few very dangerous fishes that live exclusively in cool waters. Native to the Atlantic coasts of Europe and N. Africa, weevers are considered quite a delicacy in France, but the fishery for them is small due to the violence of the venom. During spring and early summer weeverfish move into coastal waters to spawn.

. These are small (18" max.) drab fishes with frowning mouths, and venomous spines on back and gill covers. They often have turquoise highlights around mouth and eyes, but otherwise are sand or gravel colored.

How they get you: Like stingrays, weeverfish bury themselves just under the sand. But unlike stingrays, weevers will dart out and strike very accurately at anything that moves near them.

.

. Wading, swimming or even paddling in shallow Atlantic waters can be a risky business, as can fishing with hook and lineunless you know weeverfish.

Symptoms: A weeverfish sting results in immediate burning, stabbing or "crushing" pain. This reaches an intense peak within ¹/2 hour or less; victims are prone to scream, roll around on the ground or pass out.

. One early account speaks of a weever-stung fellow - whacking off his finger to relieve the pain: a more recent report mentions fishermen flogging themselves with heavy implements and trying to set fire to the wounds as last-ditch means of getting some relief. The pain is, in a word, radical. Over the next few hours after the stinging, the entire area near the sting will swell up and take on a bruised discoloration; this will last 2 weeks or longer.

. Treatment: As with stingray stings. . Get emergency medical help as soon as possible. Opiates are useless against the pain,but magnesium chloride, a mild anaesthetic, dissolved in the hot-soak water may help somewhat. Gangrene may develop in it (properly treated wounds, often necessitating amputation. Complete recovery will take weeks or months.

Octopus. There are many species of octopus, most of which are harmless to man. However, one species, the tiny blue-ringed octopus, is highly venomous. A bite from this six-inchlong creature can cause death in less than a minute (depending on the victim's sensitivity or allergic reaction to the venom.)

. A close relative of the octopus, the squid, has been known to attack man and even ships.

TENTACLES: The octopus uses its eight arms (which may reach a length of 60 feet in the giant squid) for grasping and holding prey.

BEAK: The octopus has a sharp, parrotlike beak in the center of its circle of arms.

. VENOM: The venom of the blue-ringed octopus is a neurotoxin released from specialized salivary glands directly into the bite wound.

PREDATOR: sharks, seals, man PREY: crustaceans, mollusks

.Cone Shell

Cone shells are attractive and colorful and highly prized by shell collectors (one shell brought a price of $2,000.) But one should be extremely cautious about picking up a living cone shell because some species (such as the Episcopal cone shell) are highly venomous. The animal injects the venom by means of a harpoon-like tooth located at the tip of its tongue.

. It can sting so rapidly that victims may not even notice they have been stung.

VENOM: The venom is a neurotoxin which creates a general numbness over most of the body and has been known to cause heart and respiratory failure within minutes.

http://grimwade.biochem.unimelb.edu.au/cone/index1.html

P O R T U G U E S E M A N- O F- W A R .

This jellyfish is actually a floating colony of smaller animals with tentacles that are armed with stinging cells. A person stung by these tentacles experiences intense and long lasting pain which may even paralyze the victim's respiratory system and thereby causes drowning.

. CAMOUFLAGE: Most jellyfish are nearly transparent, which makes them difficult to see as they float on the surface of the water.

TENTACLES: The most dangerous jellyfish have dozens of streaming tentacles which may reach

a length of 50 feet. These tentacles are armed with hundreds of thousands of tiny stinging cells called

. nematocysts; each nematocyst con

tains minute amounts of venom similar to cobra venom.

STING: A jellyfish is usually very painful. The effects can range from a mild reaction to shock, paralysis and even death.

[Box jellyfish is considered the most venomous marine creature. It can kill more people than stonefish, sharks and crocodiles combined].

Sea Anemone.

The sea anemone or "flower of the sea" is an animal that is found fastened to rocks or coral in tidepools and coral reefs. It catches food with the tentacles that spread out around its mouth. Each tentacle is_.armed with stinging cells called nematocysts. The poisonous nematocysts protect the anemone from predators.

. The anemone can "fire" these nematocysts to stun or kill prey. The tentacles then pull the prey into the anemone's mouth.

SIZE: Anemones range from 3-4 inches wide up to 2 feet across (giant anemone of Australia).

. POISONOUS TENTACLES: The effects on a person who accidentally touches a sea anemon can range from a mild rash of slow-healing welts to extremely painful, almost paralizing stings.

PREDATOR: fish, sea stars

.Sea Urchin

A sea urchin is a globe-shaped invertebrate with a spine-studded shell encasing its body. The brittle, sharp spines stick out of its body like pins in a pin cushion. The spines of some sea urchins are filled with venom.

.SPINES: Sea urchins pose a potential danger since they are difficult to see when burrowed into rocks and crevices. The sea urchin's spines are brittle and sharp and can easily become lodged in an intruder's flesh.

PREDATOR: fish, sea otters

PREY: algae, decaying matter

.Walrus

Although this marine mammal is often thought of as a friendly, comical creature, it is an extremely powerful predator and can be very dangerous when protecting its young. Walrus have been known to kill animals as large as polar bears, beluga whales, and even killer whales in attempts to guard their young.

. Any person that ventures into a walrus's territory and threatens the young is in danger. Entire herds (100 or more) have been observed attacking boats that contained hunters, smashing their huge bodies against the boats and even plunging their tusks through the planking.

SIZE: A bull walrus can weigh as much as 3,000 pounds and grow to a length of 12 feet.

.

TUSKS: The tusks are actually canine teeth which can grow to a length of three feet and are sharp enough to be lethal weapons.

PREDATOR: killer whale, man

PREY: fish, clams, squid, octopus

. On that cheerful note, we end this glimpse into the bizarre and painful world of dangerous and venomous marine life. Remember that the ocean is the original source of almost everything we value ---our food, our water, our waves, ourselves, and that nature is always in balance ... good and evil, yin and yang. If the waves and conditions are perfect, that's the time to be suspicious. Danger of one kind or another is hiding there, somewhere. Go for it - but be careful!

.

. Sharks-Myth or Menace

by Steve Lissau

July 1980

Surfer Magazine V21 #7..pp33-35

. They say that being attacked by a

shark is about as probable as being

struck by lightning, but when you spot the greyish, torpedo-like form of a big

shark cruising toward you only twenty feet away, the theoretical odds are not very comforting.

. Fortunately, few of us will ever tangle with a share, but when swimming, diving or surfing in the ocean, we will nevertheless think about their foreboding jaws and rows of razor-sharp teeth. For these primitive beasts, which have been on the earth for about three hundred million years, are the only large group of animals left on earth that are capable of eating man - a fate that must be the most horrible death imaginable.

. Yet most shark attacks are single-bite affairs, with the animals using their teeth and abrasive hides to lacerate the victim rather than to tear off a chunk of flesh, suggesting that they were not motivated by hunger. With fewer than one hundred attacks a year around the world, sharks are more a psychological threat than a physical one. But they are a threat, nevertheless, that prevents us from fully enjoying the ocean.

. Tigers of the Sea

Like the sea itself, sharks are shrouded in mystery, and scientists know very little about them. No one knows exactly how many sharks live in different parts of the world, nor do they know much about their breeding and migratory habits. And, as a result of the lack of information about sharks, they have acquired a reputation for being unpredictable.

. Part of the problem is that there are more than three hundred and fifty different species and they all seem to behave differently. Only a handful of these are actually dangerous.

Most of the big offshore sharks that live in the open ocean - such as the Mako, Silky and the voracious Great White (which of course was the villain of "Jaws" and the subject of the film "Blue Water, White Death") -

. rarely stray into coastal waters, and they are mainly a hazard in nautical disasters. However, they do come close to shore occasionally, as- the teeth marks of a Great White shark found in a surfboard after a 1969 attack at Makaha Beach, Hawaii indicate. (The shark had apparently been lured in by the carcass of a dead whale.)

. Sharks that live closer to shore include the Sandbar, Tiger, Hammerhead, Galapagos and Gray Reef. Tiger sharks, which sometimes grow to lengths of fifteen feet or more, currently lead Great Whites in numbers of confirmed attacks. They are the most vicious of the inshore sharks and are known to eat almost anything.

. Such varied items as a woman's handbag, birds, milk cartons, tinfoil, rags, bits of other sharks and human remains have been found inside their stornachs. Tiger sharks can be identified either by their large bodies, blunt noses or the vertical stripes on their bodies when young.

. A Feast of Frenzy

Though the Tiger shark is the only species that feeds so indiscriminately, most people refuse to eat any type of shark meat, probably because of the animal's man-eating reputation and the fear of cannibalism by proxy. This attitude was largely responsible for the elimination of shark from Japanese style fishcake in Hawaii.

. Moreover, sharks were gods to the old Hawaiians, and each family, had their own particular shark god or "aumakua" (which was supposedly born of a shark father and a human mother) that . protected them in the sea. Though it would have been unthinkable to eat one's own aumakua, it apparently was alright to eat someone else's.

. So while the early Hawaiians did eat sharks, they ate only certain species, arid the flesh of "Niuhi," the Great White shark, was forbidden to women.

When properly prepared, the flesh,of most sharks is extremely tasty,, and sharks are regularly eaten in Australia, New Zealand, Canada; Japan and in parts of Europe. In California, shark is, sold as " greyfish.“The only real problem with shark meat is that it's

laden with a metabolic waste called urea that gives off ammonia after the fish dies, thus leaving the meat with a pungent odor. However, the urea can be removed after filleting the meat by soaking it in brine and a little vinegar for about six hours and then freezing it for two or three weeks. Furthermore, fresh shark that is iced immediately won't smell. Shark can be served in any of the ways that swordfish is typically prepared.

. Interesting Observations

How often will you see sharks in the water? Probably never, unless you happen to do a lot of scuba diving in waters known for sharks. Most inshore sharks seem to prefer depths of one hundred fifty feet or so, but as the attack records indicate, they frequently do venture into shallow water. Most shark attacks occur at dusk and dawn, when visibility is limited

and reef fish are separating from schools and are heading back to the security of their holes. (Day fish hole up at night, while night fish hole up during the day.) Since predators like sharks tend to single out stragglers from fish schools, dawn and dusk are the limes when they are most likely to be ^searching for food.

. Moreover, the low light levels give them an advantage since it's easier for them to stalk prey in the darkness and their vision is rather poor anyway.

It should be no surprise, then, that under these conditions of obscured visibility, sharks occasionally bite people thinking they're fish.

Though many attacks seem to be a case of mistaken identity, some are motivated by other factors.

. For example, a shark may attack defensively when molested by a diver or startled by a swimmers sudden entrance to the water. Moreover, when sharks are feeding in a group, they are particularly voracious, and, while in a "feeding frenzy;' they are liable to strike at almost anything.

Some sharks, most notably the Pacific Grey Reef, tend to defend a certain territory which they regard as home,

. and they will attack any person who intrudes in their domain. Typically, they will "threat posture" before attacking, lowering their pectoral (side) fins, hunching their bodies and thrashing their heads wildly from side to side. (So far, threat posturing has been observed only with Grey Reef sharks,) but others, like the Great White apparently attack because they fear nothing and are just plain mean.

. Some Smart Advice

While surfing or swimming at the surface. one has-little chance of seeing a shark and even less of fending him off. Sharks do not necessarily cruise with their dorsal fin out of the water, although they are attracted to objects at the surface when foraging for food. Though a surfboard probably doesn't provide much protection, the chance of an attack is minute compared to that of a freeway collision,

. and with a little common sense it can be reduced even more. Here are some simple guidelines:

Avoid areas that are known for sharks, especially if the water is murky, and leave the water if fish are behaving in an unusual manner. Stay away from spearfishermen since they attract sharks. Swim and surf during daylight

hours and keep splashing (which-sounds like the flutters of a wounded fish to a

. shark) to a minimum. Since human blood probably both attracts and excites sharks, do not go in the water if you have a bleeding wound. (A shark's sense of smell is so keen that it can detect one part of blood in a million parts of water.) Do not swim in areas near channels or deep drop-offs, which provide easy access for sharks.

. Avoid swimming at dusk, dawn or during the night. It you ever happen to spot a shark, keep an eye on him and swim quietly to shore using the breast or side strokes.

Remember, sharks cue in on fleeing prey, so don’t swim too quickly. In unfamiliar areas, ask local residents about shark dangers before venturing out..

. Since their vision is comparatively poor, sharks are most sensitive to bright, reflective colors and vivid contrasts. Thus, a person wearing a dull colored swim suit that matches his skin, would be less likely to be spotted by a shark. Body contrast caused by uneven tanning apparently has also been a factor in several attacks.

Many attacks have been a direct result of spearfishing, since sharks are attracted to both blood and the low frequency sounds produced by the flutters of speared fish. Both stimuli are a dinner bell to sharks, with their keen sense of smell and sensitive lateral line - that can detect the vibrations of a wounded fish from distances as great as three hundred yards.

. (Smell brings them in slower than sound, but from greater. distances.) Currents can carry blood: from speared fish seaward, attracting far away sharks to its source As they excitedly home in, they occasionally bite the fisherman instead of his fish.

Dangerous Game Most

If you do see a shark while snorkeling

or scuba diving, you are in a much better position to deal with hire than a person swimming obviously on the surface. Sharks are curious animals and are always looking for a meal. Consequently, one may start circling you, gradually_. coming closer and closer. When this happens, you should leave the water as quickly and as quietly as

. possible without taking your eyes off the shark. For, as shark expert Rhelt McNair pointed out in a recent article in Skin. Diver magazine, sharks circling a diver seem to be very aware of his eyes, and they will keep their distance as long as they know that they are being watched. However, the moment one turns away, they will move in. When a shark starts making close passes, many divers recommend taking evasive action toward the animal in order to

. drive him off. Providing that the shark is not a very big one, you may be able to scare him away by simply moving toward him while yelling and blowing bubbles. If this doesn't work, you might try to hit him with a blunt object such as the butt of a speargun (sharks often react aggressively when poked with a sharp object like a spear or knife) in his eyes, gills or snout, which are the most sensitive parts of his body.

Though my friend the late Jose Angel, who used to hunt sharks underwater for sport with an explosive powerhead, once told me that sharks behave like scared dogs when they know they are being stalked, one should also remember that aggressive action toward an otherwise docile shark may cause it to attack in self-defense.

.A defensive approach is recommended with excited sharks such as a threat-posturing Grey Reef. By backing yourself up against a wall or large rock (if one is available), which will prevent the shark from maneuvering around you, you will force him to come at you from a head-on direction, which he may not want to do. In this situation, the animal will sometimes withdraw and sometimes attack.

If he chooses the latter option, you will at least be in a good position to deliver a blow to one of the sensitive areas of his body before he hits you, and the surprise contact may drive him off. But if it doesn't, the odds are that you will be bitten only once. Afterwards, you should immediately try to reduce the bleeding using both direct pressure and a tourniquet (if the wound is on an extremity).

. Loss of blood is the main cause of death from shark attack.

So sharks, like ancient dragons from

the deep, continue to be the symbol of

fear in the ocean, and because of this many ideas about sharks are myths. Two erroneous beliefs are that they must always keep moving in order to breathe, and that porpoises are capable of killing them.

. To the contrary, many species of sharks (notably the Reef Whitetip, which sleeps in caves during the day) can remain motionless for long periods, since they have muscles to pump water through their gills: and porpoises will curly occasionally fight sharks as a last resort to protect themselves or their ,young. Moreover, they don't always win, and scientists have found it

impossible to get a porpoise to attack a shark under controlled laboratory conditions.. But sharks themselves are not myths: they are more like characters in a recurring bad dream, lurking in the shadows beneath the indigo surface of the sea.

. Though the odds against attack are as great as being struck by-lightning, you don't need to live through the experience to respect the danger and take precautions to reduce the risk.

Review answers

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