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Shark Facts

Common Sharks Caught off Ocean City

Angel Shark Mako Shark
Atlantic Sharpnose Shark Sand Shark
Blacknose Shark Sandbar Shark
Blacktip Shark Sand Tiger Shark
Blue Shark Spinner Shark
Dogfish (Spiny & Smooth) Thresher Shark
Dusky Shark Tiger Shark
Hammerhead Shark  

Mako Shark
Mako Shark

The Shortfin Mako Shark (Isurus oxyrinchus "sharp nose"), commonly just called Mako Shark despite not being the only species of mako, is a large shark of the Lamnidae family.

With a full-grown size of 9-13 feet (2.754 m). It has been reported to weigh up to 1750 pounds (800 kg) and has a bluish top and a white underside. Although the sexes grow at about the same rate, females are thought to have a longer life span. Females grow larger and weigh more than the males. Shortfin Makos are renowned for their speed and their ability to leap out of the water.

The shortfin mako is found in temperate and tropical seas all around the world.

The sharks speed has been recorded at over 22 miles (35 kilometers) per hour, with perhaps a burst speed of up to 60 miles (100 kilometers) per hour.

This high leaping, boat attacking fish is sought as game worldwide. Some of the largest makos in the world can be found in New England waters. The closely related Longfin Mako Shark, Isurus paucus, is found in the Gulf Stream or warmer offshore waters. Shortfin Makos were popularized in the movie Deep Blue Sea.

The Shortfin Mako Shark is a yolk-sac ovoviviparous shark, meaning it gives birth to live young who feed off of a sac full of yolk in the womb. The gestation period for a Mako Shark is 15-18 months. Mako embryo in the female's body literally consume each other to get nutrients. This is called intrauterine cannibalism. (From Wikipedia, the free encyclopedia)

Blue Shark
Blue Shark

The Blue Shark (Prionace glauca) is a carcharhinid shark. They are surface predators in the deep waters of the world's temperate and tropical oceans. They prefer cooler waters and are not found, for example, in the Gulf of Mexico, the Adriatic or Red Sea. Blue Sharks are known to migrate long distances from New England to South America for example. Although generally lethargic, they are capable of moving very quickly if the need arises. Blue Sharks are viviparous (give live birth) and are noted for their large litters of 25 to over 100 pups. They feed primarily on small fish and squid although they are perfectly capable of taking larger prey should the opportunity present itself. They are often found in schools segregated by sex and size.

Blue Sharks are light bodied with long pectoral fins. The top of the body is deep blue lightening on the sides. The underside of the shark is white. The animals grows to lengths of 3.8 meters or more, but the usual size is 1.8 to 2.4 meters. Typical weight is 30 to 50 kg. Blue Sharks are not easily confused with any other species. They are occasionally sought as game fish. The flesh is edible, but not widely sought after. Blue Sharks are frequent accidental catches by commercial fisherman seeking swordfish or tuna.

Blue Sharks are rarely or never found in shallow water and thus are not included in lists of sharks endangering humans. However, they are believed to attack victims of air and sea disasters. (From Wikipedia, the free encyclopedia)

Thresher

Thresher sharks are large lamniform sharks of the family Alopiidae. Found in all temperate and tropical oceans of the world, the family contains three species all within the genus Alopias.

Like all large sharks, threshers are slow growing and are therefore threatened by commercial fisheries. Other than for its meat, the sharks are hunted for their liver oil, skin (for leather), and their fins, for use in shark-fin soup.

The genus and family name derive from the Greek word alopex, meaning fox. Indeed the Long-tailed Thresher Shark (Alopias vulpinus) is named the Fox Shark by some authorities.

Named for and easily recognized by their exceptionally long, thresher-like tail or caudal fins (which account for 50 percent of their total body length), thresher sharks are active predators; the tail is actually used as a weapon to stun prey. By far the largest of the three species is the thintail thresher (Alopias vulpinus) which may reach a length of 7.6 metres and a weight of 348 kilograms. The bigeye thresher (Alopias superciliosus) is next in size, reaching a length of 4.89 metres; at just 3 metres, the pelagic thresher (Alopias pelagicus) is the smallest.

Thresher sharks are fairly slender, with small dorsal fins and large, recurved pectoral fins. With the exception of the bigeye thresher, these sharks have relatively small eyes. Coloration ranges from brownish, bluish or purplish gray dorsally with lighter shades ventrally.

Although occasionally sighted in shallow, inshore waters, thresher sharks are primarily pelagic; they prefer the open ocean, staying within the first 500 metres of the water column. They are also found in coastal waters over continental shelves.

Pelagic schooling fish (such as bluefish, juvenile tuna, and mackerel), squid and cuttlefish are the primary food items of the thresher sharks. They are known to follow large schools of fish into shallow waters. Crustaceans and the odd seabird are also taken.
Thresher sharks are solitary creatures which keep to themselves. They do not appear to be a threat to humans, although some divers have been whacked with the upper tail lobe. It is known that thresher populations of the Indian Ocean are separated by depth and space according to gender. All species are noted for their highly migratory or oceanodromous habits.

No distinct breeding season is observed by thresher sharks. Fertilization and embryonic development occur internally; this ovoviviparous or live-bearing mode of reproduction results in a small litter (usually 2-4) of large well-developed pups, up to 150 centimetres at birth in thintail threshers. The young fish exhaust their yolk sacs while still inside the mother, at which time they begin feeding on the mother's unfertilized eggs; this is known as oophagy.

Thresher sharks are slow to mature, males reaching sexual maturity between 7-13 years of age and females between 8-14 years in bigeye threshers. They may live for 20 years or more. (From Wikipedia, the free encyclopedia)

Hammerhead Shark

The hammerhead shark (genus Sphyrna) is a member of the family Sphyrnidae. The only other genus of Sphyrnidae, Eusphyra, contains only one species, E. blochii, the winghead shark).

The eight species of hammerhead range from 26 m long, and all species have projections on both sides of the head that give it a resemblance to a flattened hammer. The shark's eyes and nostrils are at the tips of the extensions.

It is an aggressive predator that eats fish, rays, other sharks, cephalopods, and crustaceans. It is found in warmer waters along coastlines and continental shelves.

The shape of the head seems to act as a wing, aiding in close-quarters maneuverability, allowing sharks to execute sharp turns without loss of stability. It also seems to help in electrolocation by separating the receptors, thus giving hammerheads a wider area of search. These sharks have been able to detect an electronic signal of half a billionth of a volt. The hammer shaped head also gives these sharks larger nasal tract, increasing the chance of finding a particle in the water by at least 10 times as compared to other 'classical' sharks. Hammerheads have proportionately small mouths and seem to do a lot of bottom-hunting. They are also known to form schools during the day, sometimes in groups of over 100. In the evening, like other sharks, they become lonely hunters.

Reproduction in the hammerhead shark occurs once a year and each litter contains 1215 pups. Hammerhead shark mating courtship is a very violent affair. The male will bite the female until she acquiesces, allowing mating to occur. Unlike many other shark species, the hammerhead shark has internal fertilization which creates a safe environment for the sperm to unite with the egg. The embryo develops within the female inside a placenta and is fed through an umbilical cord, much like in mammals. The gestation period is 1012 months. Once the pups are born the parents do not stay with them and they are left to fend for themselves.

Of the eight species of hammerhead, three (3) can be dangerous to humans: the scalloped, great, and smooth hammerheads.

Since sharks do not have mineralized bones and rarely fossilize, it is their teeth alone that are commonly found as fossils. The hammerheads seem closely related to the carcharhinid sharks that evolved during the mid-Tertiary Period. Because the teeth of hammerheads resemble those of some carcharhinids, it has been difficult to determine when hammerheads first appeared. It is probable that the hammerheads evolved during the late Eocene, Oligocene or early Miocene.

There are two schools of thought for the odd head shape of the hammerheads. One states that it is because of the greater area for sensors to scan the bottom of the seafloor for food and the other that it provides lift (Hammerheads are one of the most negatively buoyant of sharks) and added maneuverability. Both of the theories are probably correct. (From Wikipedia, the free encyclopedia)

Dogfish

The name dogfish is applied to a number of small sharks found in the northeast Atlantic, Pacific, and Mediterranean, especially those in the three families Scyliorhinidae, Dalatiidae and Squalidae. The name is applied only loosely and does not signify a close taxonomic relationship. A number of other unrelated fish, notably the bowfin,eelpout/burbot are also sometimes referred to as dogfish and commonly sold as Rock Salmon (or Huss) as Fish and chips.

Spiny Dogfish
Two features distinguish the spiny dogfish from the smooth variety. First, rows of small white dots run along its slate-grey sides, and second, it has a sharp spine in front of each of its two dorsal fins.

The shark uses the spine defensively by curling around in a bow to strike an enemy. The spines are also thought tobe slightly poisonous.

Spiny dogfish are common in the Mid-Atlantic region and are considered pests by commerial and sportfishermen because it has no great value on the local market and doesn't put up much of a fight when hooked.

Smooth Dogfish
(Mustelus canis) -- Averaging 3 to 4 feet in length, the Smooth Dogfish Shark is one of the most abundant sharks on the East Coast.

The smooth dogfish is found in great numbers in summer in the Delaware Bay and more of them are caught here than all of the other sharks combined.

They will leave the area in mid-October when the water starts to cool and by early November most of them will have headed south. They won't return until mid-April or when the water rises above 50 degrees.

Smooth dogfish have many low, flat, pavement-like teeth that crush and grind more than they actually bite or tear. They feed mainly on lobster, crabs, small fish, razor clams and small hard clams.

Sandbar Shark

Common names include brown shark, queriman shark, and thickskin shark.
Order - Carcharhiniformes
Family - Carcharhinidae
Genus - Carcharhinus
Species - plumbeus

The sandbar shark is a coastal-pelagic species that inhabits temperate and tropical waters. It is the most abundant species of large shark in the Western Atlantic. It can be found in mid-Atlantic waters from May to September in the Delaware Bay area, which appears to be a mid-point in its migration to southern wintering and northern summering grounds.

The Sandbar Shark has a massive set of teeth that are triangular, serrated and razor sharp.

Because is it so scarce in this area, Sandbar shark meat isn't available commercially, but the fish does yield delicious meat.

C. plumbeus is essentially a bottom-dwelling, shallow coastal water species that is seldom seen at the water's surface. It tends to prefer waters on continental shelves, oceanic banks, and island terraces but is also commonly found in harbors, estuaries, at the mouths of bays and rivers, and shallow turbid water. It is believed that the sandbar shark favors a smooth substrate and will avoid coral reefs and other rough-bottom areas. It spends most of the time in water from 20-65 m (60-200 ft) deep but undoubtedly moves into deeper water to undergo migration.

Sand Shark

(Carcharias taurus) -- The Sand Shark likes to spend time in the bays and the larger ones are usually caught in the upper parts of our bays.

Most sand sharks are found from Cape Cod south, but they aren't found in great numbers below the Delaware Bay.

The sand shark's mouthful of teeth can send chills through you. Still, this is not a man-eater. Instead, it is somewhat sluggish and lives on the bottom of the sea or close to it.

The sand shark appears in our waters mostly in summer when the surface temperature reaches 60 to 70 degrees.

Most weigh less than 150 pounds but some have been caught weighing more than 200 pounds. The average length is 4 to 6 feet with the largest growing to 10 feet or more.

Blacknose Shark


The blacknose shark Carcharhinus acronotus is a common shark in inshore and moderately deep waters of the western Atlantic Ocean (North Carolina to the Bahamas to southeastern Brazil). This requiem shark averages about 4 feet (1.2 m) long, but can grow to 6 1/2 feet (2 m) long. It has gray skin above (and white skin below) and the snout is dark; some of these sharks have spots that fade with age. The fins are darker at the edges. When threatened, it exhibits a "hunch" display: this shark arches its back, raises its head, and lowers its tail. The blacknose is harmless to people - it is fished as game. The blacknose eats small fish; it is eaten by larger sharks and people. It is viviparous (it has a yolk-sac placenta to nourish the embryos). There are 3 to 6 pups in each litter; the gestation period is 8 to 9 months long. Newborns are 10-19 inches (25.5 to 48.5 cm) long. Classification: Order Carcharhiniformes (ground sharks), Family Carcharhinidae (requiem sharks), Genus Carcharhinus, Species C. acronotus

 Angel Shark

(Squatina californica)

The angel shark is lives on the sandy bottom of the ocean. It lives offshore, in bays, and along the fringe of kelp forests. Its flat body is gray with olive blotches and it has large pectoral fins that look like wings. Its shape and color help it to hide in the sand on the ocean bottom.

The angel shark preys on other fish by burying itself in the sand and ambushing them as they swim by. It likes to eat small fish and squid, and though it's not very dangerous to people, it can inflict a painful bite if surprised or harassed.

The female angel shark lays an egg case that looks like a little drawstring purse and is sometimes called a mermaid's purse.

 

 

Shark Facts:

There are three types of embryonic development, oviparous, ovoviviparous, and viviparous.

Did you know the largest shark known is called the Whale Shark? Some grow to be almost 50 feet long! One of the smallest sharks is the Midwater Shark which only grows to around 10 inches long.

Sharks have been known to shed as many as 30,000 teeth in a lifetime.

Certain shark species bite with the force of 42,000 pounds per square inch - compared to the adult male human's bite of 150 pounds per square inch.

At least eight known species of shark are endothermic, or warm blooded - controlling their temperature much as humans do.

The largest organ in a shark is the liver. The shark lacks flotation bladders and that is why most sharks will sink if they stop moving. The liver contains an oil, called squaleen, which helps to float sharks. The sharks stomach can be turned inside out if the shark swallows something it cannot digest. Male sharks have a pair of claspers that are formed from the inner pelvic fins. The shark's brain is similar in weight to those of birds and mammals making the shark the most intelligent of fish. Sharks can even be trained. The olfactory bulb is close to the front part of the brain.

THE SHARK'S SIXTH SENSE: The shark has all the senses that we humans do but they also have one we don't have. Tiny pores on the snout leads to jelly-filled sacs known as ampullae of Lorenzini. This sense can detect very weak electrical fields that can detect electrical "vibes" as weak half a billionth of a volt. Struggling or scared animal creates a strong electrical current, which flows through the water, and even though it gets weaker as it travels away from the animal sharks can pick it up. Every animal sends electrical "vibes". A shark can find animals under the sand, and at night, and when at the last moment of attack when the eyes are rolled back and it cannot see. In many cases when doing shark research the shark would attack the boat and other objects instead of the food offered. Humans used to
think that the shark was just a stupid, crazy eating machine that went after anything. It turns out however that the shark when coming for the prey would roll it's eyes back and have the ampullae of Loranzini direct it to the prey. The boat gives out very strong electrical "vibes" which confuse the shark and direct it to the boats direction, and since the shark cannot see at the moment it would not know the boat is not the prey. Hammerhead sharks have a large number of ampullae of Lorenzini on their heads. Hammerheads use their heads like mine sweepers to find stingrays, and other prey in the sand. Large number of hammerheads can be found near underwater volcanoes which attract them from miles away with their electrical fields. The rare and strange goblin shark has a strange snout hanging over is head which may be used the same way as a hammerheads head and help it hunt in the deep dark water it lives in. Goblin shark teeth have been found in underwater electrical cables.

THE LATERAL LINE: The lateral line is another sense that we human do not have. The lateral line is a fluid filled canal that is lined with tiny hair like receptors that are attuned to vibrations made by prey. These lateral lines are located just under the skin on the shark's snout and along both sides of the body. These lines are also in bony fish. Fish (sharks included) can also use these lines to sense water currents and pressures and even sounds. Some say that the bumping behavior of sharks allows external taste receptors to see if the organism is edible (this may explain why sharks often bump objects).

SMELL: Unlike the nostrils of "higher" animals, sharks are not used for repertory functions. The shark can sense one molecule of blood in a million molecules of water. Each nostril is divided by a skin flap, which separates the water flowing in and out. As the fish swims water enters the nostrils and through the nasal capsule that contains lamellae. Lamellae increase the shark's sensitivity to odors. The olfactory bulb is close to the front of the brain.

HEARING: The shark has an excellent sense of hearing and can hear the low pulsing sounds made by animals swimming, splashing, and struggling. These sounds are too low for humans to hear, however sharks can hear them from a thousand miles away. Sharks do not have external ear flaps, but instead have ears inside their heads on both sides of the brain case. Each ear leads to a small pore on the sharks head. A shark's inner ear can also detect acceleration, and gravity.

SIGHT: It was once thought that sharks had very bad eyesight, and were nearly blind. It is know known that sharks have very good eyesight, some better then ours. Like cats, a shark's eye contracts or expands to alter the size of the pupil, according to how much light there is. In the back of the eye there is a layer of cells known as the tapetum lucidum. The cells reflect light back onto the retina. This is where images are focused, making good use of light. Due to this a sharks can see in dim light, and the
eye "glows" like a cats when light is shined on them. With pigment layers a shark can protect it's eyes on sunny days. The shark's eyes also have cells called rods, and cones. The rods work in dim light and are sensitive to changes in light. The cones may allow sharks to see color. We humans have rods, and cones. Fish lack eyelids because they don't need to blink and clean their eyes due to their watery environment. During attack some sharks use their nictitating membranes (translucent eyelids) to protect them from the thrashing animal. Sharks that have no nictitating membranes, like the great white for example roll their eyes into the back to their heads. The size, shape, and overall look of a shark's eye depends on their environment. Deepwater sharks have large eyes to take in more light, while smaller eyes are on sharks that live closer to the surface.
 



Last Updated: 04/12/2006

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