Download Structured to Survive

Grades
4–5
Unit 4
Structured to
Survive
Two Talented Swimmers:
bit.ly/toptalentepi4
Which animal is Georgia Aquarium’s top talent?
You decide! The electric eel takes on the manta ray
in a swim-off before a panel of three penguin judges.
Take the plunge to check out the shockingly athletic
displays by these amazing animals in the “Aquarium’s
Top Talent” video presented by Georgia-Pacific.
Next Generation Science Standard:
Structure and Function, 4-LS1-1
Plants and animals have both internal and external structures that serve various functions in
growth, survival, behavior and reproduction. The electric eel and the manta ray are among the
most unusual animals seen swimming in warm waters. They both have internal and external body
structures that help them survive. The electric eel has gills but gets most of the oxygen it needs by
breathing air. Its complex circulatory system allows it to remain underwater for up to 10 minutes
before surfacing for air. The manta ray is a filter
feeder; it unfurls fins on either side of its
WORDS TO KNOW
mouth to funnel water through its mouth
and out of its gills, trapping the plankton it
circulatory system: the body system of blood,
eats in its mouth.
vessels and the heart
external: something that is located on the outside
gills: an organ for obtaining oxygen from the water
internal: something located on the inside
INTRODUCING THE LESSON:
1. Display pictures of a manta ray and an
electric eel. (An Internet search will provide you
with a variety of choices.) Point out that both of these animals live in warm waters; electric
eels can be found in the Amazon and Orinoco rivers of South America, and manta rays swim in
tropical waters of the Atlantic Ocean.
2. Explain that animals have internal and external structures that work in different ways to help
them survive. Tell students that both the manta ray and the electric eel have gills, which are
organs that obtain oxygen from water. Then perform the simple demonstration below to show
how gills work.
DEMONSTRATION STEPS
1. Mix a cup or more of ground coffee with water in a measuring cup to make a soupy
mixture. Tell students the coffee represents oxygen.
2. Use a rubber band to secure a paper towel over a large clear cup, explaining that the
paper towel represents fish gills.
3. Pour the coffee mixture into the cup. Have students observe what happens. (The paper
towel filters the coffee grounds from the water the same way gills remove oxygen
from the water so a fish can breathe.)
3. Tell students that manta rays breathe solely through gills. Electric eels have gills too, but they
get only about 20 percent of their oxygen through their gills. They must swim to the surface
about every 10 minutes to inhale the rest of the air they need through their mouths.
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
Grades
4–5
Structured to
Survive
Fishy Research
Booklet
Next Generation Science Standard:
Structure and Function, 4-LS1-1
Plants and animals have both internal and external
structures that serve various functions in growth, survival,
behavior and reproduction.
ESTIMATED LESSON TIME: Two 35–40 minute
class periods
MATERIALS:
copy of the booklet pattern page for each student
access to online and print reference materials
paper strips
scissors
tape
Background Information:
The electric eel’s current is made using three pairs of electric organs. The organs consist of
thousands of special cells, or electrocytes, that store power like tiny batteries. The cells discharge
to create a burst of electric current.
The manta ray’s mouth is on the top of its head instead of the bottom. It has two sets of fins.
When hunting for food, it unfurls its cephalic fins. These
act as a funnel, guiding water into the manta
ray’s open mouth as it moves through the
WORDS TO KNOW
water.
cephalic: of or near the head
current: a stream of electric charge
organ: a part of an animal made up of cells and
tissues and designed for a certain task
Lesson:
Day 1
1. Divide the class into groups of three or
four students, designating each group as a research team for either the electric eel or
manta ray. (Make sure there is an equal number of teams studying each animal.)
2. Have students in each research team use the reference materials to identify special
body structures (internal and/or external) that help their animal survive in its
habitat. Tell students to take notes and be prepared to share their information.
©2014Georgia-Pacific. Text and design by The Education Center, LLC
Grades
4–5
Structured to
Survive
Day 2
1. Pair each manta ray research team with an electric eel research team. Then provide up to
10 minutes for the paired teams to share information.
2. Follow up by having each student make a pocket booklet by following the directions below.
Internal structure that helps it survive
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MANTA RAY
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MANTA RAY
DIRECTIONS FOR EACH STUDENT:
1. Cut out the booklet pattern on the bold outer line.
Then, starting at the large •, cut on the dotted
line between the two pictures.
2. Fold the paper to make two sections as shown.
3. To make two pockets, tape along the outer
side and bottom by each photo. (The photos
are the front of the pockets.)
4. On the inside of the booklet, write the
information you learned about the
manta ray and electric eel. Write other
interesting facts on paper strips and store
the strips in the booklet’s pockets.
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The male electric eel cares for its
offspring. It builds the nest for the female to
lay eggs in and then guards the eggs until they
hatch. The male also guards the young eels in
its mouth for several weeks after they hatch,
not feeding itself during that time.
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
ELECTRIC EEL
ELECTRIC EEL
DID YOU KNOW?
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
MANTA RAY
ELECTRIC EEL
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Internal structure that helps it survive:
External structure that helps it survive:
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Internal structure that helps it survive:
External structure that helps it survive:
NameDate
Specialized structures (4-LS1-1)
Body Part or Behavior?
Read each statement about manta rays.
Then trace the border around each statement according to the color code.
Color Code
blue—about a body part/structure that helps with survival
green—about a behavior that helps with survival
1. When it eats, water flows
into a manta ray’s mouth
and passes out through
its gills. Plates along
the gills trap the food in
its mouth so only water
passes back out.
3. Manta rays often
feed at night.
That’s when
they have a
better chance of
finding food.
2. The manta ray
moves slowly in
the water. This
allows it to take
in a great deal of
water and food.
4. The manta ray has two
sets of fins. The cephalic
fins are about 20 feet wide
when they’re spread out,
allowing the manta ray to
scoop more water toward
its huge mouth.
6. Some manta rays feed on
their own, barrel-rolling
backward to funnel planktonrich water through their
mouths and gills.
8. Researchers believe
the manta ray may use
its cephalic fins to pick
up electrical signals
from other animals
moving in the water.
5. The manta ray’s mouth
is located on top rather
than at the bottom of its
head. This allows more
water to enter its mouth
as it swims.
7. If plankton is thick, manta rays may
form feeding chains. They loop
around to form columns, causing the
water to spin like a cyclone and pull
the plankton closer to them.
9. Manta rays may be
black, blue, brown or
gray. Their coloring
helps camouflage them,
letting them blend with
their surroundings.
10. Although they tend to
stay close to coral reefs,
manta rays are known
to migrate into the open
seas in search of food.
Bonus: Are manta rays dangerous
for humans? Research to find out!
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
Note to the teacher: Students will need markers, colored pencils or crayons to complete this page.
STRUCTURED TO SURVIVE
Body Part or Behavior?
ANSWER KEY
1.blue
2.green
3.green
4.blue
5.blue
6.green
7.green
8.blue
9.blue
10. green
Bonus: Answers will vary.
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
NameDate
Structure and function (4-LS1-1)
The Shocking Truth
About Electric Eels
Electric eels generate electricity to survive. This
ability helps them defend themselves, catch food and
navigate underwater. Learn more about these “shocking”
animals below.
Predators and Prey
The body of an electric eel contains thousands of power
cells. These cells are like tiny batteries. They are packed into
the tail, which makes up 80% of the body. Eels can generate
600 volts of electricity. That’s five times the power of a wall
socket! A thick skin protects eels from shocking themselves.
Electric eels are not fierce. They only use their electrical
power to defend themselves or to stun prey. The shock does
not kill the prey. It just makes the prey stop moving. Eels do not have upper teeth. So they have trouble
eating fish that are thrashing around.
Other fish are afraid of eels, so eels do not have many enemies. Humans usually avoid them too.
People along the Amazon River rarely eat eels because the eels can give off shocks eight hours after
death. Luckily, very few humans have ever died from electric eel shocks. However, they could have a heart
attack or stop breathing. People also have drowned after being shocked.
Other Survival Tactics
Electric eels live in muddy streams and ponds. They are almost blind. They navigate underwater by
giving off a weak electrical charge in all directions. This helps them detect other fish. It also helps them
identify other electric eels and find a mate.
Electric eels have gills, but they breathe underwater only 20% of the time. They need to swim to the
surface frequently and gulp air though their mouths. This feature helps eels survive in muddy water and
during dry season, when there isn’t much oxygen in the water.
Answer the questions.
1. Where is the power source in an electric eel’s body?___________________________________________
2. Why don’t electric eels electrocute themselves?______________________________________________
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3. True or false? Electric eels kill their prey before eating it._______________________________________
4. Besides defending themselves and catching food, what else do electric eels do with their electrical
charge?________________________________________________________________________________
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5. How do electric eels breathe?_____________________________________________________________
_______________________________________________________________________________________
©2014 Georgia-Pacific. Text and design by The Education Center, LLC
STRUCTURED TO SURVIVE
The Shocking Truth About
Electric Eels
ANSWER KEY
1.tail
2. Their thick skin protects them.
3.false
4. navigate underwater and find a mate
5. through their gills and through their mouths
©2014 Georgia-Pacific. Text and design by The Education Center, LLC