Summer Worlds Tour: Sharks
Audience: All groups are included in this outline, but differentiated
instruction is included
Program Size: Varies for each session
Program Length: 1.5 hrs.
Time Management & Materials: (per activity)
5 minutes
30 minutes
5 minutes
35 minutes
30 minutes
15 minutes
What do you know about sharks?
Shark jaws biofact
SMARTBoard
Shark stuffed animal
Shark short storybook
Wild Reef Exhibit Visit
Role in Environment
Build-a-Shark
Construction paper
Scissors
Balloon
Glue sticks
Googley eyes
Markers/Crayons/Colored pencils
Aquatic Show
Environmental Impact on Sharks
SMART Board game
Notecards
Colored pencils/Crayons
Procedures:
I.
What do you know about sharks?
A. Hold up biofact of shark jaws and ask campers what animal they think it is from.
Once campers guess sharks, ask them why they guessed that. As students describe a
shark, point out relevant parts on the biofact (i.e. rows of teeth, sharp teeth).
B. Transition into “What do you know about sharks?” For 5-6 year olds, hold up a shark
stuffed animal and put a picture of a shark on the SMART Board. For 7-8 & 9-10 year
olds, record their responses on the SMART Board. (This SMART Board slide will be used
as a comparison after the campers visit Wild Reef).
C. For 5-6 year olds, read a short story on sharks, and then inform campers they are
going to the Wild Reef to look at real sharks. For 7-8 and 9-10 year olds, inform
campers they are going to the Wild Reef to observe Shedd’s collection of sharks.
II.
Wild Reef Exhibit Visit
A. Either prior to visiting the Wild Reef or while visiting the exhibit, ask campers to
make basic observations about sharks (i.e. How does it move? What type of habitat
does it live in? Does it share a habitat? What types of body parts does it have? If you
were a scientist, what would you name it?)
B. Also, ask campers if they still believe the facts they mentioned earlier when asked
“What do you know about sharks?” are true. This might be an ideal time to address
any misconceptions or myths.
III.
Role in Environment
A. Ask campers what they learned while venturing around the exhibit. Discuss the role
of a shark in the environment. Topics may include: Predator-prey relationship (apex
predator), sharks ability to keep the habitat’s populations of species in balance, shark
as a fish, etc. For 5-6 year olds, instead of having a discussion, consider role playing.
Have a couple campers be sharks, and some campers are fish. Let the sharks eat (tag)
the fish. Simulate what would happen if sharks were not part of the food chain.
IV.
Build-a-Shark
A. Have pre-traced shark body parts (fins(for 7-8 & 9-10 year old groups provide specific
fins, body, mouth, teeth, nose, gills, swim bladder(7-8 & 9-10), ampullae of
lorenzini(7-8 & 9-10) on construction paper. Inform campers that they are going to
be building their own shark today. Ask 7-8 & 9-10 year old campers, “What types of
body parts does a shark have?” For 5-6 year olds, ask campers, “What are the special
parts of a shark?” If campers, need help revert to a picture of a shark. As campers
guess body parts, hold up the pre-traced drawings and hand them out to each
camper.
B. Campers will probably guess many of the parts and know what they are used for. You
can discuss how specific fins are used for steering and others for propulsion. For the
parts they are not able to guess, give them an explanation for it. For example, you
may have to explain to the 7-8 & 9-10 year olds that sharks have a swim bladder that
allow them to float to the top of the surface and sink to the bottom. An easy way for
them to understand this anatomical structure is by comparing it to a balloon (you may
even want to have a balloon as a prop). Also, you will most likely have to explain the
ampullae of lorenzini to the 7-8 and 9-10 year old groups. You can tell campers about
the extra special sense sharks possess. The ampullae of lorenzini appear as tiny black
dots on a shark’s snout and are able to sense electrical pulses. Almost every living
thing emits an electrical pulse. This allows sharks to detect where other fish are in
the water.
C. Once campers receive all the pieces of the shark, let them cut out the shark anatomy
and put it together. You may want to have a demo already made so campers have
guidance.
D. When finished, give campers the googley eyes and a glue stick to attach to their
shark. Encourage them to name their shark at this point. For the 7-8 & 9-10 year
olds, ask them to label the parts of their shark.
V.
Environmental Impact on Sharks
A. Pull up SMART Board game which entails a picture of an Ocean habitat with a shark
and several fish on it. Inform campers that we are going to observe what happens
when certain events occur in the environment (for 5-6 year old groups, you will have
to modify this wording). You will have a set of notecards with various scenarios on
them. Each scenario will correspond with a certain slide of the SMART Board game.
B. Choose a volunteer to come select a notecard and read it. For 5-6 year old groups,
you will have to read the notecard. Once the notecard is read, ask campers what
they predict will happen. For each situation read, show the SMART Board slide that
matches it. For example, one slide may be about fisherman retrieving too many
sharks out of the ocean. The shark population will decline. This will allow for the
fish populations to boom and resources to deplete.
C. After each scenario, ask campers if they have a solution to the problem on the
notecard.
D. Once you complete the game, pass out a notecard to each camper. Have the 7-8 & 910 year old campers write one thing on the notecard that they can do to help out
sharks. For the 5-6 year old groups, ask them to draw a picture of what they can do
to help sharks. Also, for the 5-6 year old groups, you may have to give them ideas.
Suggest reading a book about sharks and learning about them to help out or ask them
to recycle, turn off water when brushing teeth, etc.
E. If campers finish this activity, and time is left, let them decorate their notecard or
finish decorating their Build-a-Shark.
VI.
Aquatic Show
A. Start getting ready around 1:30.
B. Be sure to ask if campers need a bathroom break.
C. Reserved seating – enter near the south lobby entrance. Tell them you are for Summer
Worlds Tour.
© John G. Shedd Aquarium
Extra information that may be important to know or of interest:
Shark Myths
Think you know all about sharks? Well, here are some commonly held myths about sharks - how many do you think are true?
Most sharks are harmful to people.
Sharks must roll over on their sides to bite.
Sharks eat continuously.
Sharks prefer human blood.
Sharks are not discriminating eaters and scavenge the sea.
Whale sharks, the largest species of sharks, are voracious predators.
The great white shark is a common, abundant species found off most beaches visited by humans.
Sharks are not found in freshwater.
Most sharks cruise at high speed when they swim.
Sharks have peanut-sized brains and are incapable of learning.
Shark meat is poisonous to people.
All sharks have to swim constantly.
Sharks have poor vision.
Sharks are hard to kill.
A shark is a shark is a shark.
Sharks are trash fish.
The biggest enemy to sharks is man.
Source: Mote Marine Laboratory, Sarasota, Florida
Now for some insight on the topic!
Sharks are trash fish - No Way!
Sharks are a critical part of marine ecosystems, a source for knowledge to help the human condition, and the basis of a valuable
fishery.
Sharks have poor vision - Erroneous!
Sharks' eyes, which are equipped to distinguish colors, employ a lens up to seven times as powerful as a human's, and some shark
species can detect a light that is as much as ten times dimmer than the dimmest light the average person can see.
All sharks have to swim constantly - Misconceived!
Some sharks can respire by pumping water over their gills through opening and closing their mouths while at rest on the bottom.
The great white shark is a common, abundant species found off most beaches visited by humans - Not!
Great whites are relatively uncommon large predators that prefer cooler waters. In some parts of their range, great whites are close to
being endangered.
Whale sharks, the largest species of sharks, are voracious predators - Incorrect!
Whale sharks, which are the largest fish that ever lived, are plankton feeders like the great whales, thus the name.
Most sharks are harmful to people - Untrue!
Of the more then 350 shark species, about 80% are unable to hurt people or rarely encounter people.
A shark is a shark is a shark - Misconstrued!
There is no "typical" shark. The more than 350 species all differ in habitat, lifestyle and body form.
Sharks are hard to kill - Off Base!
Stress of capture weakens a shark, and so some sharks are easily killed in hook-and-line or net fishing.
Shark meat is poisonous to people - Wrong!
Although there have been some reports of people being poisoned by shark meat, the meat from the majority of sharks is edible and
delicious when properly handled and prepared.
Sharks have peanut-sized brains and are incapable of learning - Fallacious!
Sharks' relatively large and complex brains are comparable in size to those of supposedly more advanced animals like mammals and
birds. Sharks also can be trained.
Most sharks cruise at high speed when they swim - Invalid!
Although some sharks may swim at bursts of over 20 knots (23 miles per hour), most sharks swim very slowly at cruising speeds of
less than 5 knots (5.75 miles per hour).
Sharks are not found in freshwater - Forget it!
A specialized osmoregulatory system enables the bull shark to cope with dramatic changes in salinity -- from the freshwaters of some
rivers to the highly saline waters of the ocean.
Sharks are not discriminating eaters and scavenge the sea - Wrong!
Most sharks prefer to eat certain types of invertebrates, fish and other animals. Some sharks eat mainly fish. Others eat other sharks or
marine mammals. Some sharks are even plankton-eaters.
Sharks prefer human blood - False!
Most sharks don't appear to be especially interested in the blood of mammals as opposed to fish blood.
Sharks eat continuously - Preposterous!
Sharks eat periodically depending upon their metabolism and the availability of food. For example, juvenile lemon sharks eat less than
2% of their body weight per day.
Sharks must roll over on their sides to bite - No!
Sharks attack their prey in whichever way is most convenient, and they can protrude their jaws to bite prey items in front of their
snouts.
The biggest enemy to sharks is man - Absolutely! That's why man must now do all he can to preserve them.
There are almost as many myths and misconceptions about sharks as there are species. NOVA asked Dr. Samuel
"Sonny" Gruber, arguably the world's leading shark researcher, to unmuddy the waters about this most maligned of fish. A
professor of marine biology at the University of Miami's Rosenstiel School of Marine and Atmospheric Science, Gruber
has been called the "guru of sharks." He has more than 100 published scientific papers to his credit, and his work on the
behavior and physiology of lemon sharks in Bimini constitutes the most extensive studies on any shark species.
NOVA: Are sharks really the vicious killers they're made out to be?
Gruber: Most sharks are far too small to be vicious killers of men and women, and many sharks live
in the deep sea where no humans swim. The fact remains that around 100 shark attacks do occur
each year, but elephants are bigger killers; they do in 200-plus mahoots and trainers each year. Talk
about vicious—dogs kill thousands. And get this: Soda machines killed more people last year than
sharks did. People get angry at the machines when they steal the $0.75 the person honestly inserts
for a cool, refreshing soda. But if no soda comes out, people often viciously attack the machine, trying
to make it cough up the soda or the cash. The machines viciously retaliate by falling on and crushing
their tormentors.
NOVA: Do sharks have enemies?
Gruber: The greatest enemy of sharks is man. He kills and hacks off the fins of 30 to 100 million
sharks each year. That is, in three to five years fishers kill the equivalent of the entire population of
the U.S. Humans are not natural predators of sharks, as we are terrestrial hunters and didn't really
fish for sharks until we became civilized. Now we cut off fins and throw the living creature back to die
on the bottom of the sea. Is that civilized? It's true, some shark species are adapted to feed on other
sharks; a prime example is the bull shark. In theory, any large shark could consume a smaller one,
though this is not usually the case. The most numerous natural enemies of sharks are the various
parasites that can kill a shark if they get out of hand.
NOVA: Are sharks stupid compared to mammals and birds?
Gruber: I wrote a paper with Neil Schneiderman in 1975 demonstrating that lemon sharks learn
faster and retain a conditioned response longer than a cat or rabbit. Sharks and their large-brained
allies the rays have brain/body weight ratios in the range of birds and mammals. Personally, I don't
think they're as intelligent as birds or mammals—whatever intelligence is. Still, if you've ever dealt
with a chicken you'd think sharks were genius-level creatures.
NOVA: Can sharks really find prey without seeing or smelling them?
Gruber: Absolutely. A shark is like the Starship Enterprise, bristling with sensors. The most amazing
is its electrical sense. Measurements demonstrate that a shark can detect electric fields of a
magnitude similar to a 12-volt car battery placed in the middle of the Atlantic Ocean, with the positive
pole connected to Boston Harbor and the negative pole placed in the harbor at Plymouth, England.
The miniscule current flowing across the ocean—1/1,000,000,000 volt per square centimeter—would
be at a level detectable by sharks. Translated to hunting, a shark can sense a prey in turbid water or
buried beneath the seafloor by electrical sense alone. Hearing provides another cue. Sounds of
struggling fish attract sharks. Their senses are truly a marvel to behold.
NOVA: Can sharks, as I've read, really detect the smell of as
little as one drop of fish extract in a quarter-acre lagoon six and
a half feet deep?
Gruber: I've seen lemon sharks go wild over a single drop of
blood in a 2,000-gallon tank. In the underwater world of noses,
catfish and eels may take the cake, and salmon, of course, find
their home stream after a year or more at sea strictly by smell.
Wondrous! But sharks are keen predators and, because they
A Lemon shark patrols the shallows.
are always searching for food, show up first if there is fish scent
in the water. That's why chumming is so effective for sharks. It
comes down to the concentration of the stimulating chemical at the nose's receptor cell that
determines if an animal will detect a smell. That level is parts per million in sharks and parts per billion
in catfish.
NOVA: Can sharks see in the dark?
Gruber: Yes, and so can we and cats, too. But sharks are especially good at it. In tests I did for my
doctorate, I trained sharks to respond to minimum light levels and compared these to human
subjects. Sharks were about ten times more sensitive than a human tested in the exact same
apparatus. I think sharks can see by starlight on a clear, moonless night.
NOVA: Do sharks make sounds?
Gruber: They make hydrodynamic sounds when swerving and accelerating, and they make
crunching sounds with their teeth and jaws. But they don't have special organs for sound production
and apparently don't communicate with sound.
NOVA: Sharks have an endless supply of teeth?
Gruber: Yes, and they are unique in this way, too. They produce teeth continuously. Their teeth are
not set in sockets like those of other vertebrates but rather loosely and flexibly attached by tendons to
their jaws. If they didn't replace teeth continuously—up to 50,000 in a lifetime—their teeth would fall
out. That is why shark teeth are the most abundant vertebrate fossil material on the Earth and in the
sea.
NOVA: Do sharks have to keep swimming to breathe?
Gruber: Several species do, including hammerheads and mackerel sharks. Typically, pelagic sharks
that never encounter the bottom are adapted to swim all their lives. But the vast majority of sharks
have a buccal (mouth) pump and are not so-called "obligate ram ventilators." (Ram ventilators like
hammerheads and great whites must swim to pass water over their gills.) So the answer is no,
emphatically. There are even some sharks with spiracles, holes on the top of their head that allow
water to enter their gill chambers when the mouth is on the bottom.
NOVA: Do sharks have to roll over to bite?
Gruber: No way, Jose! Sharks have a unique, loose jaw suspension that allows them to raise their
snout and loosen their jaw from the braincase, thrusting it forward so that, in effect, the shark has a
terminal mouth right out there at the end. But in reality, sharks rarely bite pieces out of a prey.
Usually, they engulf them with their amazing buccal or mouth pump, which acts like a slurp gun.
NOVA: Are sharks warm-blooded?
Gruber: Mackerel sharks, including great whites, makos, threshers, and
porbeagles, have a heat-conserving mechanism known as the rete mirabile
("wonderful net"), a structure for warming blood passing over the gills.
Whites can keep their core temperature up to 15°F above ambient
seawater.
Great white shark
NOVA: Are sharks insensitive to pain?
Gruber: Hard to say, because we don't know what pain means to an animal and can hardly describe
it ourselves. Some people are almost insensitive to pain, others are highly sensitive. I have done
minor surgery on sharks, and they seem not to feel it. On the other hand, using what is clearly
aversive conditioning I was able to train sharks, showing that they do respond to pain, which can be
used as a conditioned stimulus—and a powerful one. So yes, sharks feel something we would call
pain.
NOVA: Can sharks survive finning (when the dorsal fin is cut off for shark-fin soup and the animal
released)?
Gruber: In nature, occasionally fins get bitten off with no detriment to the shark, and finned sharks
have been caught in a starved state during shark-fishing tournaments. But generally finning kills
sharks.
NOVA: Do shark embryos really eat one another?
Gruber: One group, the sand tigers, has evolved a true survival-of-the-fittest strategy in the womb.
Six to eight embryos are produced in each of the mother's two oviducts. The strongest, fastestgrowing sibling kills and consumes the others, so that sand tigers typically have two babies, one per
oviduct. This is really a great system, as only the best are born. They're big, up to two-fifths the length
of the mother. It's a good head start. Otherwise, the different groups of sharks have evolved all the
usual developmental strategies—egg laying, egg laying with eggs retained, even up to a real
maternal-fetal connection via an authentic placenta.
NOVA: Can shark cartilage cure some cancers?
Gruber: Yes and no. All cartilage—shark cartilage, cow cartilage, whatever—possesses an antiangiogenesis (AG) factor that, if injected into a solid tumor, will cause the growth to dry up, shrink,
and die. Merely eating shark cartilage will give you some extra calcium, but it will be useless against
cancers, as no complex molecules pass through the gut wall. Even if the AG factor got through, how
and why would it seek out the tumor like a magic bullet? I say if you want calcium take supplements!
This hocus pocus is bad for cancer victims, as they get false hope and discard their effective but
uncomfortable treatments for snake oil, and they die. And it is bad for sharks, as they have to give up
their skeletons for nonsense.
NOVA: Do sharks get cancer?
Gruber: The Registry of Tumors in Lower Animals housed at the Smithsonian Institution has
recorded tumors, and I have seen things that appear to be neoplasms. But sharks are very resistant
to cancers. Carl Lauer at the Mote Marine Laboratory in Florida has shown that the usual carcinogens
do not induce cancer. I have several theories as to why they're so resistant. First, the AG factor in
their cartilage is very strong in the living shark, though they still have the same problem of getting it to
a potential tumor site. Next, sharks have a primitive but very potent immune system—the key to
cancer resistance. Finally, shark DNA is very conservative and resistant to mutations.
NOVA: Are sharks primitive?
Gruber: New evidence suggests that the cartilaginous fishes to which sharks belong may be the
oldest of the jawed vertebrates. So they are ancient. Indeed, some sharks survived as a group for
200 million years. (They are all gone now; no trace of them exists outside of some teeth and scales.)
But modern sharks, skates, and rays arose only 30 million years ago. The biological definition
© John G. Shedd Aquarium