Shark Scavenger Huntreview

What is mutualism?Mutualism is the mutual beneficial

association between different kinds of organisms

The shark benefits the remora and the pilot fish by giving them protection and providing them with food scraps. The remora helps the shark by eating the tiny parasites which grow on a shark’s skin.

What is a baby shark called? SHARK BABIESBaby sharks are called pups.  Just like there are many types of sharks, there are also different ways that sharks come into this world.  There are three ways that sharks are born:•eggs are laid (like birds)•eggs hatch inside the mother and then are born•pups sharks grow inside the mother (like humans)Sharks can have from 1 to 100 babies at a time, depending on the type of shark.  The ones with pups that grow inside the mother have fewer babies at a time than sharks that lay eggs outside the body.Sharks do not care for their babies after they are born, but they do search for a safe place where they can lay their eggs or give birth.

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Where is the lateral line on a shark? It is located on both sides of the shark’s body

– running from the snout to the tail, just under the shark’s skin.

What is the purpose/function of the lateral line?If you wiggle your hand in a sink full of water, you

can feel the water motion you create. A shark senses prey in the distance by detecting water movement made by fish or other swimming prey. Sharks have a special system, called a lateral line, that picks up the vibrations in the water. This narrow strip of sensory cells runs along the sides of the body and into the head. Sharks use the lateral line to detect the erratic motions of sick or wounded prey (easy-to-catch meals) when they are about three to 10 feet away.

What are denticles?Denticles are teeth like scales covering a

shark’s body. Denticles are mainly used for protection and aids in streamline swimming.

Why do most sharks have to swim at all times?Sharks are fish, and virtually all fish breathe through the use of

gills. These are the collection of slit-like openings on the sides of fish, located behind the head. Behind the gills are networks of complex capillaries. These networks of tiny blood vessels withdraw oxygen from the water as it passes over them.

Bony fish have swim bladders (which inflate like a balloon) so that they can hover motionless in the water. But most sharks do not have swim bladders. Their constant motion allows water to pass through their gills so that they can breathe.

Most species of shark breathe by swimming, using the forward motion to pass water over their gills. These sharks must be in constant forward motion, or they will suffocate.

What is the function of the spiral valve?This is the lower part of the shark’s intestine

that is corkscrew in shape. In the spiral valve, food is broken down into its basic parts, or nutrients.

What is the function of the ampullae of Lorenzini?These are tiny pores covering the snout of

the shark that detect electrical impulses in the water. These pores can help a shark locate prey, orient themselves, and detect changes in water temperature.

What is the function of the spiracle?The spiracle is an opening just behind the eye

in many sharks (and all rays) that allows water into the gills while the shark is eating (or while the ray is buried in sand).

Where is Sharktooth Hill?It is found in Kern County in Bakersfield,

California

What is unusual about the Lake Nicaragua Shark?The Lake Nicaragua Shark (also called the

bull shark) is unusual because it has adapted to living in freshwater. It is found in Lake Nicaragua, the largest lake in Central America.

What is a feeding frenzy?A shark feeding frenzy occurs when a number of sharks

fight for the same prey. Sharks are usually solitary diners, and a feeding frenzy indicates why that might be. To an observer, it looks like the sharks lose their mind biting at anything that's in their way in an uncontrollable rage. They thrash around, their snouts elevating and their backs arching, all signs that indicate an impending attack. Some accounts tell of sharks eating each other and of sharks continuing to feed even after they've been disemboweled by other sharks.

What are barbels?Nasal barbels are sensory projections near

the nostrils and mouth of some sharks (e.g., the nurse shark). These barbels are whisker-like feelers used to taste and feel.

What sharks have barbels?Nurse sharkBarbeled hounstooth sharkCarpet sharkSawtooth sharkAngel shark

What does viviparous mean?Viviparous means producing live young

instead of eggs (like humans).

What does oviparous mean?Oviparous means producing eggs that

develop and hatch outside the maternal body (like birds).

What does ovoviviparous mean?Ovoviviparous means producing eggs that are

hatched within the body of the mother shark and then born alive.

What does oophagus mean?Oophagus literally means “egg eating”. It

happens in some species of sharks when unborn pups eat the unfertilized eggs released by the mother.

What is a mermaid’s purse?This is a name sometimes given to the egg

cases of sharks such as the swell shark and the angel shark. The egg case is shaped like a piece of kelp with a drawstring. One baby shark grows inside it.

What is rugae?These are the folds inside the stomach that

aid in the absorption of food.

What are some facts about the megaladon?Megalodon was a giant shark that lived between 2

million and 16 million years ago. Little is known for sure about these giant predators

because all that remains of their existence are fossilized teeth. But what teeth they are! These giant shark teeth range in size from 3 inches long to 7 inches long.

Adults were 55 to 60 feet long and weighed as much as 100 tons.

They probably dined on whales.Megalodon had a truly global distribution, terrorizing

whales in warm-water oceans all over the world.

What interactions might sharks have with humans?Fisheries

Shark attacks

Sport fishing and commercial fishing

Conservation and research

What are the conditions under which most shark attacks occur?Warm, shallow waterShiny objectsDiving in deep coral seas or wreck sites (their

territory)SplashingTime of day (dusk or dawn)Resembling preyMurky water, blood, swimming around their food source, teasing or bothering the

shark

What are the predators of sharks?

Although sharks have very few natural predators, sometimes rival sharks might attack other sharks. Some animals eat shark eggs and, therefore, thin the shark population in this way. Orcas (killer whales) have also been known to attack sharks. Humans often hunt sharks for sport, and in some cultures humans use the shark’s fins for food and even medical purposes. Also, sharks are sometimes killed accidentally when caught in large fishing nets.

What are the hunting strategies of the following sharks?

Megamouth – It has a glowing lining inside its mouth that attracts krill (small shrimplike crustaceans).

Angel shark – It uses camouflage to capture its prey. It mostly eats fish, crustaceans, and some mollusks.

Gray reef shark – It swims in an exaggerated fashion, arching its back and lowering its pectoral fins. Scientists believe this behavior is used to intimidate other sharks (and even divers) that might come near its territory.

Why have sharks survived for millions of years?Sharks have a unique ability to adapt to

different environments. They are uniquely in tune with their environment and have very few natural predators.

How are sharks and rays alike?They both are cartilagenous fish.They both have gill slits instead of gill covers.

How are sharks and rays different?Rays are generally bottom-dwellers. Although some

sharks are bottom-dwellers too, most live in other zones of the ocean.

Rays have a flat body while sharks are more fish-shaped.

Rays have no free upper eyelid while sharks do.Rays have a spiracle for breathing (draws in water

and takes it to gills, then ejects it through gill slits). Most sharks breathe by drawing water in through the mouth, passing it over gills, and then ejects it through gill slits.

Swimming movements are different.

Be sure to study all of this information for your test next week.

Good luck!