1. Sharks’ Sense of Smell
Edwin
ISM
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2. Have you
ever been
bitten by a
shark?
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3. What is a shark?
A type of fish / Mostly heard in the news about surfers
bitten by sharks even in our area like Monterey Bay!
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4. Shark basic information
• Been around about 400 million years
• Over 400 species
• Largest 39 ft, smallest 6.7 in
• Never run out of teeth; use 20,000 in life
• Feed on plankton, squid, small fish, and other
SHARKS—STRANGE!
• Found in all seas
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5. Sharks’ anatomy
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6. Shark senses
• Like us, sharks’ senses are smell, taste,
touch, eyesight, and hearing.
• A shark’s primary sense is its sense of
smell; 2/3 brain dedicated to smell.
• Sharks have good eyesight. They have
color vision –so they see color pictures!
• Sharks are very sensitive to low frequency
sounds: hear sounds more than 700 ft
away!
• Sharks have taste buds in their mouth.
• Sharks touch things by biting them.
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7. Sharks’ sense of smell
How do sharks sense smell under water?
• Sharks’s primary sense is the sense of
smell. The smell organs in the noses of
some sharks are so strong that they can
detect ONE droplet of blood in A MILLION
drops of sea water.
• Two nostrils at the front of a shark’s face
pull water into a nasal chamber where
smells are detected. Water flows through
the nostrils giving the shark olfactory
information. This is how sharks smell
things.
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8. Sharks’ sense of smell, continued
The chemistry of sharks’ sense of smell
• Oh, boy this is the real HARD part, 
since it’s getting SO technical. First I didn’t
understand the question, nor did my
parents. I asked Mr. Spedding. I was told
it’s about molecules and atoms that I
actually missed before I came here. Then
I emailed Mr. Manny Ezcurra, the shark
expert at the Monterey Aquarium for help.
He gave me some pointers, which are
very very helpful. So here you go!
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9. Sharks’ sense of smell, continued
• Sharks are attracted to the chemicals
found in the guts of animals.
• Smells begin when odor molecules that
travels through water stimulate olfactory
receptor cells in the nostrils.
• The cell sends electrical impulses to a
particular microregion of olfactory bulb.
• The microregion that receives the
information then passes it to sharks’ brain.
This is how sharks sense a certain smell. 9

10. Sharks’ sense of smell, continued
• Sharks are guided by the nostril that
detects the prey’s odor first.
• The odor reaches one nostril before the
other, signaling whether to turn left or
right.
• The ocean is a smelly place, full of odors
or scents of hundreds of different kinds of
animals. Sharks can sort it all out.
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11. Chemistry of sharks’ sense of smell
—SUMMARY
Molecules (of odor)  Receptor
cells (in nostrils)
 (Sends electrical impulses to)
Microregions (of olfactory bulbs)
 (Passes info to) Sharks’ brains
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12. Sharks’ sense of smell —Scenario
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13. Any questions?
Thank you for listening!
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