Lesson 3: Coral Adaptations
Abstract
In this two part lesson, students will compare and contrast the adaptive strategies of branching
coral and mounding coral through participation in an interactive PowerPoint and a hands-on lab
activity. Students complete a note-taking guide during the PowerPoint that provides background
information to be used during the lab. In the lab activity, teams of 4 students construct different
corals out of paper and test the design stability against physical disturbance.
Learning Objectives
After participating in an interactive PowerPoint and conducting a hands-on experiment, students
will be able to make inferences about why organisms with certain traits are found in their
specific habitats. Students will also be able to communicate ideas concerning the cohabitation of
competing species in the same habitat.
Level
Middle school
Time required
One 50-minute class period
California Science Education Standards (Grade 7)
Grade 7, Content Standard 3: Evolution-- Biological evolution accounts for the diversity of
species developed through gradual processes over many generations. As a basis for
understanding this concept:
a. Students know both genetic variation and environmental factors are causes of evolution
and diversity of organisms.
b. Students know the reasoning used by Charles Darwin in reaching his conclusion that
natural selection is the mechanism of evolution.
e. Students know that extinction of a species occurs when the environment changes and
the adaptive characteristics of a species are insufficient for its survival.
Grade 7, Content Standard 7: Scientific progress is made by asking meaningful questions and
conducting careful investigations. As a basis for understanding this concept and addressing the
content in the other three strands, students should develop their own questions and perform
investigations. Students will:
a. Select and use appropriate tools and technology (including calculators, computers,
balances, spring scales, microscopes, and binoculars) to perform tests, collect data, and
display data.
c. Communicate the logical connection among hypotheses, science concepts, tests
conducted, data collected, and conclusions drawn from the scientific evidence.
e. Communicate the steps and results from an investigation in written reports and oral
presentations.
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 1
Materials
Student worksheets
PowerPoint presentation (provided)
Lab Materials (see Advance Preparation)
Example paper coral structures (see Coral Model Construction Instructions)
Advance Preparation
Make copies of Warm-up worksheet, Coral Conundrum note-taking guide, and Coral
Conundrum Lab (1 per student)
Gather the following for each group of 4 students …
10 sheets, 8.5 x 11in paper
5 sheets, 8.5 x 11in cardstock
2 pairs of scissors
10 in of masking tape
1 pencil
1 ruler
Teacher Background
Coral belongs in the animal kingdom. Almost all corals are colonial organisms, which means that
each of the large coral structures that make up a reef are made of hundreds to hundreds of
thousands of individual animals. Each individual animal is called a polyp.
Polyps have a stomach that opens at one end that is surrounded by a circle of tentacles. The
polyp uses these tentacles for defense, to capture small planktonic organisms for food, and to
clear away debris. Inside the tentacles are small stinging cells called nematocysts that help
immobilize prey before it is drawn into the stomach. Once the food is digested, waste products
exit through the same opening.
Most corals also contain symbiotic alga cells within their polyps. These algae, called
zooxanthellae (or symbiodinium), have a mutualistic relationship with the coral. The coral
provides the algae with a protected environment and some of the compounds needed for
photosynthesis. In return, the zooxanthellae produce oxygen and supply the coral with important
metabolic compounds (like glucose, glycerol, and amino acids). In poor environmental
conditions coral polyps expel their zooxanthellae, which results in a white, bleached appearance.
This process, called coral bleaching, leads to the death of the polyps and is a major concern to
reef health throughout the world.
Coral requires specific environmental conditions in which to grow. Because of the bond between
zooxanthellae and coral polyps, coral must have plenty of light to promote photosynthesis. This
means that the water in which coral is found must be clear and shallow to allow sunlight to
penetrate effectively (most corals are found in less than 60 meters of water, although there are
exceptions). Waters with high turbidity often do not support corals due to the large amounts of
particulates that get swept into the water column.
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 2
There are many different groups of coral species, such as deep sea corals, temperate water corals,
soft corals, stony corals, etc. The species featured in this lesson are stony corals, meaning that the
polyps process calcium carbonate to build large, hard structures that support the soft tissue of the
polyps. The focal species are found in the tropics, and can be categorized into 2 groups—
branching corals and mounding corals. These 2 groups have developed different adaptations for
surviving in the same habitat. The point to be made to the students is that natural selection can
lead to many different successful strategies even for the same environmental factors.
The environmental factors that are central to this lesson are space, physical disturbance, and
sunlight. Below is a description of each group of coral and the advantages and disadvantages
each has for the environmental factors specified above.
Branching Corals
Branching corals include species like Staghorn coral and Elkhorn coral. These species are from
the same genus, Acropora. Like the name suggests, branching corals grow various sized
protrusions that resemble the branches of a tree or animal antlers.
Mounding Corals
Most massive, mounding corals belong to the families Mussidae, Meandrinidae, and Faviidae.
Like the name suggests, mounding corals are massive structures that are generally round in
shape, like large rocks.
Although these 2 groups of coral have very different strategies and often are competing against
one another for space, they still co-exist in the same environment. In general, the speed at which
branching corals grow is balanced by the susceptibility to damage by physical stress and the
aggressive nature of mounding corals.
See the tables below.
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 3
Branching Corals
Abiotic Environmental Factor
SpaceÆ enough physical area
in which to collect sunlight
and/or food particles, grow,
and reproduce.
SunlightÆ the essential
driving energy factor of
photosynthesis.
Physical DisturbanceÆ
intense wave action created
during storms, scuba divers
hitting the reef, boat anchors,
etc.
Advantageous Adaptations
Branching corals grow much
faster than mounding corals.
Because of this adaptation, the
branching corals can gradually
overtop any neighboring
mounding corals. The
mounding coral underneath
the branches does not receive
as much sunlight and does not
come into contact with as
many food particles
(plankton). This can cause the
overgrown species to
eventually die, which prevents
further competition for the
branching coral
Branching corals are more
self-nourishing (autotrophic)
because the multi-layered
growth form of branching
corals allows for a greater
surface area to collect light for
photosynthesis. The polyps of
branching corals tend to be
small, thereby exposing the
maximum area of internal
zooxanthellae to light. The
fast-growing nature of
branching corals enables them
to grow up toward the sunlight
and resist shading.
As mentioned previously,
branching corals grow faster
than mounding corals.
Therefore, if there were a
disturbance large enough to
demolish all the coral in a
given reef, the settlers that
would begin to grow first
would be branching corals.
Disadvantages
In some situations the fast,
continued growth of branching
corals may lead to their own
demise. Branching coral
colonies can become
overcrowded and die, and
eventually are overgrown by
another species. The quickly
built skeleton of branching
corals can also be more easily
damaged by physical
disturbances, such as wave
action.
Branching corals have
adaptations that maximize
photosynthesis, not catching
prey. So although these corals
are capable of heterotrophic
consumption, their heavy
reliance on autotrophic
processes can be detrimental if
conditions for photosynthesis
are poor. For instance, if the
water contains too many
particulates, it becomes cloudy
which prevents sunlight from
penetrating to the polyps.
Branching corals would be at
a disadvantage in this
situation.
Branches are by their very
nature more fragile than a
large, solid mound of coral.
Heavy wave action from a
storm can break branches and
diminish the size of the overall
coral.
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 4
Mounding Corals
Abiotic Environmental Factor
SpaceÆ enough physical area
in which to collect sunlight
and/or food particles, grow,
and reproduce.
Advantageous Adaptations
These corals can extrude long
filaments or tentacles
containing digestive juices
towards any neighboring
competitor. These substances
literally dissolve the
competitor’s polyps and create
a dead space in which the
mounding coral can grow.
Often a “hallow” of dead space
can be observed between 2
coral species exhibiting this
aggressive behavior (see
PowerPoint).
SunlightÆ the essential
driving energy factor of
photosynthesis.
Mounding corals rely more on
heterotrophic consumption
than branching corals. The
polyps of mounding corals
tend to be larger and thicker
than branching coral polyps,
which gives them greater
surface area for intercepting
zooplankton. This
heterotrophic strategy allows
mounding corals to live in
slightly more turbid waters
(where particulates in the
water column block sunlight)
because they can obtain energy
from sources other than
photosynthesis.
Physical DisturbanceÆ intense Mounding corals are massive,
wave action created during
rock-like structures that can
storms, scuba divers hitting the withstand a higher level of
reef, boat anchors, etc.
physical disturbance than the
spindly branches of their
competitors.
Disadvantages
Mounding corals have a
slower rate of growth than
branching corals. There is
always a possibility that a
branching species could grow
over the mounding coral and
prevent it from receiving light
and/or food particles
(plankton).
A reliance on heterotrophic
consumption might be a
disadvantage in an area with
less plankton in the water
column. These mounding
corals cannot survive solely on
energy derived from
photosynthesis.
If a physical disturbance is
strong enough to damage
mounding coral, their recovery
is much slower than for
branching corals due to their
slow growth rate.
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 5
Natural Selection Boxes
This is an effective tool for helping students visualize the process that lead to beneficial changes
(adaptations) in a species. The boxes work with almost any organism in any environment.
Simply choose a focal organism and a focal environmental factor and complete the cycle. See
example below for more details…
Resources
Background information for this lab was gathered from this website:
NOAA CoRIS
http://coris.noaa.gov/about/biology/
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 6
Instructional Procedure: Lesson 3, Coral Adaptations
Time
5 min
Instruction
Warm-up/Review: As students sit down
they must fill in an adaptations chart for at
least two example coral reef organisms.
One must be a coral.
The organism cards from the previous
lessons can be on the desks to aid students.
Have students share ideas with a partner.
15 min
Introduction to Coral
The teacher presents a PowerPoint that
reveals the characteristics of coral.
Many different examples of corals are
represented, but special attention is paid to
branching corals and massive, mounding
corals (these are the basis of the lab).
Students complete a worksheet during the
presentation that focuses on the affect of
environmental factors on coral adaptations.
Students compare and contrast the
strategies used by branching corals vs.
mounding corals for the same
environmental factors.
10 min
Reasoning
Students review some of the concepts
from the previous lessons that might be
pertinent to this upcoming lesson (such
as adaptations, environmental factors,
natural selection, etc.)
Since this lesson is focused on coral
adaptations, it is beneficial for the
students to begin to develop ideas about
this unique group of organisms.
Students might have trouble identifying
coral as a living organism since it does
not have many of the standard traits they
associate with animals (such as eyes, or
a head, etc.). This introduction activity is
designed to help students realize that
coral does share the characteristics and
needs common to all living organisms.
After illustrating that coral is indeed a
living organism, students apply the 4
steps to Natural Selection boxes (used in
previous lessons) in order to understand
how natural selection operates on this
group of organisms. These boxes will
serve as a reference for students to use
during the lab.
Review the 4 steps to Natural Selection
boxes using coral competing for space.
Complete 2 sets of boxes, one in which
branching coral out-competes mounding
coral and then vise versa. After this
activity, students should realize that
different growth strategies can be
advantageous adaptations depending on the
environmental circumstances.
This introduction is an important
Coral Growth Lab Introduction
reinforcement of the scientific method.
Students need a chance to be exposed to
Students are given the lab sheets and read
a problem and use their critical thinking
the investigation question: “What type of
skills to develop their own educated
coral is best adapted for our classroom
guesses.
environment?”
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 7
Materials, including design examples, are
placed at tables.
As a whole class, students brainstorm
possible environmental factors within the
classroom that could influence their paper
coral adaptations.
10 min
Students use the brainstormed ideas to
develop independent hypotheses using the
“I think…because…” format.
Coral Growth Lab
Students are in groups of 4. Groups are
given 4 minutes to construct as many
corals of design #1 as possible. Then
students are given another 4 minutes to
construct as many corals of design #2 as
possible.
The “I think…because…” format
encourages students to defend their ideas
with background information rather than
making a random guess.
This activity allows students to be
kinesthetically involved with the
scientific content. Students will actually
be able to experience how different
adaptations are useful under different
environmental conditions.
Students record how many of each design
they were able to construct in the given
time.
10 min
Teacher introduces a disturbance
(“hurricane winds” from a fan). Students
record the remaining numbers of each
design after the disturbance.
Coral Growth Lab Data Analysis
Students construct a bar graph to compare
the percentage of surviving coral for each
design after the disturbance.
Advanced Students can take the data from
all of the groups, find the average
percentage of surviving coral for each
design and add this to their bar graph.
After visually seeing the results in graph
form, students will literally see how
each design is advantageous in its own
way.
The overall concept students should
grasp is that natural selection has lead to
2 different growth strategies that both
work in specific situations.
Students use their tables/graphs and work
as a team to write answers to the remaining
conclusion questions on their worksheets.
5 min
Wrap-up/Connection to real Coral Reefs
At this point, students have learned the
basics of coral structure and have
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 8
Teacher initiates a discussion with this
question: On the island of Moorea, there
are different types of ocean habitats. At the
reef crest large waves continually crash,
but in the lagoon the waters are more
consistent. Make a hypothesis about the
types of corals you would find in these
locations.
experienced the benefits of different
growth strategies. Now they can apply
this background knowledge to develop
ideas about a real life situation.
Going Further (extensions for High School)
Have students extrapolate the number of coral colonies built over time using dimensional
analysis. Students find the class average number of colonies constructed in 5 minutes and then
use dimensional analysis to find how many would be made in an hour, a day, a year, etc…
Ex:
7 corals x
5 min
60 min
1 hr
x
24 hr
1 day
x
365 days
1 yr
= 735, 840 corals made per yr
Assessment
Formative Assessment Opportunities
1. The warm-up at the beginning of the lesson prompts students to apply concepts learned in
the previous lessons. The teacher monitors student responses to look for concepts
students are struggling with, which then allows the teacher to review the specific ideas
that students need help understanding.
2. Several of the PowerPoint slides prompt students to apply their knowledge of the
influence of environment on organism adaptations. Student responses can again help the
teacher look for concepts students are struggling with, which then allows the teacher to
review the specific ideas that students need help understanding.
3. The background research portion of the lab requires students to apply their knowledge of
environmental factors to a completely new, albeit analogous, scenario (the classroom).
This is a perfect opportunity for the teacher to find out if students really grasp the concept
of environmental factors.
Summative Assessment Opportunities
The students will each turn in their completed worksheets at the end of the lab. The final wrap-up
questions require students to apply the knowledge gained from the lesson. The students’ abilities
to develop ideas and use facts from the lesson to support those ideas can be assessed through this
section of the worksheet.
Teacher Instructions for Coral Model Construction
For Mounding Coral…note, measurements should be EXACT, make them carefully with the
ruler
1. Cut 2 strips from the cardstock. One is 4 inches wide down the length of the paper,
the other is 2.5 inches wide down the length of the paper.
2. Every 1.5 inches down the length of the paper make a small mark
3. Use the pencil to poke 4 holes vertically in the strips about at each 1.5 inch mark.
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 9
4. Use 1 inch of tape to secure the strips into circles. Place the taller circle inside of the
shorter circle.
For Branching Coral…note, measurements are approximate! Don’t spend time making exact
measurements
1. Cut a strip of regular paper 2.5 inches wide down the length of the paper. Roll into a
cylinder and tape together with 0.5 inches of tape.
2. Cut a square of regular paper 4.5 inches by 4.5 inches. Place the square on top of the
cylinder.
3. Rip strips of regular paper 0.5 inches by 4 inches.
4. Crumple the strips slightly with your hand and place them on top of the square.
Left: Mounding Coral
Right: Branching Coral
Teacher Instructions for Coral Testing
Physical disturbance is represented by a fan. In a pinch, using your lungs to blow on the model
corals will work. Place the fan next to the corals and then switch on the fan for 30 seconds.
Students record the number of coral structures that remain after the disturbance.
If time allows, use a textbook to test models as well. Place the book atop each structure. The
flimsy branching coral will crumble, while the cardstock mounding coral will support the weight
of the book.
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 10
Name________________________________________ Date ______________ Period ________
Warm-up: Coral Reef Organism Adaptations Chart
Use what you have learned about coral reefs to fill in the chart for 3
organisms living in this habitat. One of the organisms must be coral.
Organism
Coral
Environmental
Factor
Adaptation
How the adaptation helps
with survival
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 11
Name________________________________________ Date ______________ Period ________
Coral Conundrum
1. What is coral?
Coral is part of the __________________ kingdom. The large reef structures are
made of many __________________ animals living together in a _____________.
Each individual animal is called a _____________. Draw an arrow from each
definition to its location on the polyp…
Tentacles: Capture
____________ for
food with stinging
cells.
Stomach opening:
Where _______
goes in and _______
comes out.
Zooxanthellae: _______
cells that give the polyp
sugars after photosynthesis.
Describe 2 things that coral needs in its
environment in order to survive…
__________________________________________
_____________________________________________________
_____________________________________________________
2. What are some types of coral? Record facts about 2 types of coral
shown during the presentation.
Type of Coral
Facts
One adaptation that might help this
coral survive in its environment is…
*
*
*
*
*
*
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 12
3. Branching Coral vs. Mounding Coral
Name 3 environmental factors corals must cope with in tropical waters…
_____________
_______________________
_______________________
Even though branching and mounding corals face the same environmental factors,
each group has evolved different adaptations to survive in the same habitat…
Environmental Factor
Branching Coral Adaptation
Mounding Coral Adaptation
Grow _____________ than
mounding coral.
______________ competitors
with digestive juices.
The many _____________ on
this coral provide a lot of area
to collect more light.
Large ___________ allow this
coral to capture more food, so
it does not need as much light.
These corals grow
__________, so recover more
_________________________ quickly when damaged.
These corals are tough and do
not ____________ as easily as
branching coral.
_____________
Corals need room to grow!
_________________
for photosynthesis.
_________________________
Corals can be broken by storm
waves, boat anchors, etc.
4. Natural Selection How do coral species develop these adaptations?
Overproduction
Selection
Variation
Competition
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 13
Name________________________________________ Date ______________ Period ________
Coral Conundrum: Lab
Question: What type of paper coral is best adapted for our classroom
environment?
Background Research: You will be constructing branching coral and
mounding coral. Describe at least 2 environmental factors within this classroom
that might influence paper coral adaptations…
1. ________________________________________________________________
__________________________________________________________________
2. ________________________________________________________________
__________________________________________________________________
Hypothesis: I think _____________________ coral is best adapted to our
classroom environment because ________________________________________
__________________________________________________________________
Experiment: Your team has 5 minutes to build each type of coral.
Data Table
A
B
Coral Type
# of colonies built
in 5 minutes
# of Colonies still
standing after physical
disturbance
% of coral that survived
physical disturbance
A / B x 100 =
Percentage of
Surviving Coral
Percentage of Surviving Coral Graph
100
90
80
70
60
50
40
30
20
10
Branching
Mounding
Class Branching Class Mounding
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 14
Conclusions: Your choice! Answer #1 or #2, AND #3 or #4. Total of 2 answered questions.
1. If the environment had no physical disturbances, which type of paper coral would be
most common in the classroom environment? Why? (use data as evidence for your idea!)
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
2. If the environment was constantly disturbed, which type of paper coral would be
most common in the classroom environment? Why? (use data as evidence for your idea!)
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
3. Was your hypothesis correct? Use your data to explain which type of paper coral is
best adapted to the classroom environment.
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
4. How do the results of this lab relate to real coral reef habitats?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 15
Name________________KEY_____________________ Date ___________ Period ________
Warm-up: Coral Reef Organism Adaptations Chart
Use what you have learned about coral reefs to fill in the chart for 3
organisms living in this habitat. One of the organisms must be coral.
Organism
Coral
Environmental
Factor
sunlight
that
Has zooxanthellae
Adaptation
energy in the form of sugar.
This provides the coral with
How the adaptation helps
with survival
photosynthesize.
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 16
Name_______________KEY_______________ Date ______________ Period ________
Coral Conundrum
1. What is coral?
Coral is part of the ___animal___ kingdom. The large reef structures are made of
many ___individual___ animals living together in a ___colony___. Each
individual animal is called a ____polyp____. Draw an arrow from each definition
to its location on the polyp…
Tentacles: Capture
__plankton__ for food
with stinging cells.
Stomach opening:
Where __food__
goes in and _waste_
comes out.
Zooxanthellae: _algae_ cells
that give the polyp sugars
after photosynthesis.
Describe 2 things that coral needs in its
environment in order to survive…
_____Coral need sunlight so the zooxanthellae_________
____can photosynthesize and provide energy. Coral also need ____
___space in which to grow, catch food, etc._______
2. What are some types of coral? Record facts about 2 types of coral
shown during the presentation.
Type of Coral
Temperate coral
Facts
* Found in Santa Barbara
One adaptation that might help this
coral survive in its environment is…
Very big polyps allow this coral to
catch large food items.
* Large polyps
* Does not form reefs
*
Answers vary
depending on
which coral
students choose.
*
*
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 17
3. Branching Coral vs. Mounding Coral
Name 3 environmental factors corals must cope with in tropical waters…
_Warm water__Coral-eating fish_ (answers vary as students make up own ideas)
Even though branching and mounding corals face the same environmental factors,
each group has evolved different adaptations to survive in the same habitat…
Environmental Factor
____Space_
Branching Coral Adaptation
Mounding Coral Adaptation
Grow __faster__ than
mounding coral.
___attack_ competitors with
digestive juices.
The many ___branches__ on
this coral provide a lot of area
to collect more light.
Large ___polyps__ allow this
coral to capture more food, so
it does not need as much light.
Corals need room to grow!
___sunlight_
for photosynthesis.
_____Physical___
_______Disturbance_____
These corals grow __fast__, so These corals are tough and do
recover more quickly when
not __break__ as easily as
damaged.
branching coral.
Corals can be broken by storm
waves, boat anchors, etc.
4. Natural Selection How do coral species develop these adaptations?
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 18
Name________________Key___________________ Date ______________ Period ________
Coral Conundrum: Lab
Question: What type of paper coral is best adapted for our classroom
environment?
Background Research: You will be constructing branching coral and
mounding coral. Describe at least 2 environmental factors within this classroom
that might influence paper coral adaptations…
1. ______Student generated, so answers will vary____
2. _______Fluorescent lighting might not be as strong as sunlight so corals might
need big polyps to capture more food
Hypothesis: I think ___mounding___ coral is best adapted to our classroom
environment because it has larger polyps and would be able to catch more food.
Experiment: Your team has 5 minutes to build each type of coral.
Data Table
Coral Type
A
# of colonies built
in 5 minutes
B
# of Colonies still
standing after physical
disturbance
% of coral that survived
physical disturbance
B / A x 100 =
branching
10
2
20 %
mounding
4
3
75 %
Percentage of
Surviving Coral
Percentage of Surviving Coral Graph
100
90
80
70
60
50
40
30
20
10
Optional as time permits
Branching
Mounding
Class
Branching
Class
Mounding
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 19
Conclusions: Your choice! Answer #1 or #2, AND #3 or #4. Total of 2 answered questions.
Time might be running out at this point, so students have the power of choice
1. If the environment had no physical disturbances, which type of paper coral would be
most common in the classroom environment? Why? (use data as evidence for your idea!)
_______The branching coral might eventually take over because it was easier to
construct. We made two times more branching coral than mounding coral in the same
amount of time._______
2. If the environment was constantly disturbed, which type of paper coral would be
most common in the classroom environment? Why? (use data as evidence for your idea!)
_______The mounding coral would be more abundant in this situation because it was
much sturdier. Only 20% of the branching coral survived physical disturbance, but 75%
of mounding coral survived.__________
3. Was your hypothesis correct? Use your data to explain which type of paper coral is
best adapted to the classroom environment.
_____________My hypothesis was not correct. I think the mounding coral is actually
better adapted to the classroom environment because even though it took longer to
build, it was able to withstand the disturbance with a 75% survival rate. With all of the
people that come and go in this room, I think a heartier coral will survive better than a
fragile, branching coral.____________
4. How do the results of this lab relate to real coral reef habitats?
_________In some ways this lab models situations that might occur in real reefs. If a
powerful hurricane ripped through a lagoon in Moorea, the branching corals would
most likely be destroyed first._______________________________________
Moorea Coral Reef Long Term Ecological Research Program
Permission granted for printing and copying for local classroom use without modification
Developed by Meghan Saxer as a part of the Research Experience for Teachers program
Development and distribution funded by the National Science Foundation
Page 20