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title or topic of activity
Cool Communication of Cephalopods
Pearson, Jared Bond, Madeleine Thompson
| Students will learn about the
amazing communication of cephalopods by working hands-on to create
their own non-verbal communication system.
|4-5, but could be adapted for younger
or older elementary students. The activity itself may be too
complicated for lower grades.
The class cephalopoda, in the phylum Mollusca, includes octopus,
squid, cuttlefish and the rare nautilus. The word “cephalopod”
literally means “head-foot.” As a class in the phylum Mollusca,
cephalopods are also related to gastropods (snails) and bivalves
Although cephalopods are in the same class, they look remarkably
different from each other. However, all cephalopods do share
several characteristics. All cephalopods have sucker-bearing
arms around the front of their heads – squid and octopus have eight
while cuttlefish and nautilus have more. Additionally, squid and
cuttlefish have two long tentacles used for grabbing prey.
Cephalopods have highly developed eyes, large brains and a sac from
which they discharge a black mucus-bound ink. Ink is used for defense
and disguise. The ink obscures the cephalopod and can irritate
the eyes of the predator, which allows the cephalopod time to escape.
All cephalopods move by expelling water from a siphon under the
head. Octopods also use their arms to crawl.
Another characteristic shared by cephalopods is their amazing ability
to communicate through the use of chromatophores. Chromatophores
are pigment-bearing cells capable of causing color changes in the
cephalopods’ skin by expanding and contracting. (See http://www.mbl.edu/publications/Loligo/squid/skin.0.html
for diagram and animation of chromatophores). The expansion and
contraction of the cells is so quick, taking only a fraction of
a second, that no other color-change in animals comes near it in
speed. When the chromatophore cell is relaxed, its surface
area is small and the color is not visible. When the muscles
contract, the surface area becomes much greater and the color is
visible. Chromatophores can express yellow, orange, brown,
red, blue and black. Each chromatophore consists of a bag containing
filaments of pigment that are attached to nerve fibers. The
functioning of the chromatophore is all under the control of the
cephalopods’ advanced nervous system. Although cephalopods
are known for their large brains, they also have a great deal of
local control of their nerves - more than any vertebrate.
Thus, the cephalopods possess incredible control over their chromatophores.
Cephalopods use their ability for color change in a number of ways.
Along with their ink sacs, they use chromatophores for predator
avoidance, either through camouflage or disruptive coloration.
Camouflage can also aid in capturing prey because prey, like predators,
are unable to see the cephalopod. Cephalopods also use their
chromatophores to communicate between themselves. A male cephalopod
might display colors as a signal of aggression to another male who
seems to be intruding on his mate. In addition, chromatophores
may be used to signal a readiness to mate. (All information in this
section comes from Moynihan, 1985.)
Camouflage - concealment by means of disguise; behavior
or artifice designed to deceive or hide.
Cephalopod – the octopods, squids and other mollusks that
possess a foot modified into arms that surround the head.
Chromatophore – a skin cell that contains pigments.
Disruptive coloration – a color pattern that helps break
the outline of an organism.
Molluscs – the invertebrates with a soft, unsegmented body;
a muscular foot; and, with some exceptions, a calcareous shell.
Tentacle – a flexible, elongate appendage.
(Definitions from Castro, 2000 and http://school.discovery.com/lessonplans/programs/octopus/)
for the activity
|We got this idea from modifying
a lesson plan entitled “The Amazing Octopus” from http://school.discovery.com/lessonplans/programs/octopus/,
which was originally developed by Don DeMember, a science resource
teacher in Germantown, Maryland. Specifically, we modified the
Colorful Cuttlefish Communication activity.
time to do the activity
|Introductory presentation will take
20-30 minutes, the activity takes 30-45 minutes (activity can be repeated),
and the concluding discussion can be adapted to the time available.
- Gain an understanding of the characteristics of cephalopods.
- Gain an understanding of the unique manner of cephalopod communication
through the use of chromatophores.
- Encourage the students to think about other forms of non-verbal
communication in the animal kingdom, including human society.
Science Education Standards. (NSES)
content standards that this lesson plan covers:
- "Students need to have an understanding of regulation and behavior."
By explaining the chromatophore system of communication, students
will gain an understanding of a particular type of cephalopod
- "Students should develop an understanding of the diversity
and adaptations of organisms"” Examining chromatophores
illustrates a unique adaptation for survival and communication
within the class of cephalopods.
Pictures of octopus, squid, cuttlefish and nautilus to show cephalopod
diversity and similarities, preferably on overheads
Video to demonstrate cephalopod color changing (if possible)
20 pieces of construction paper of at least four different colors
|Locate pictures of cephalopods
on the internet (the pictures on this site can be used in the classroom)
or in books. If possible, transfer these pictures to transparencies.
It is also very helpful to obtain a video to better demonstrate the
chromatophore change. Please see our references for several
possible video titles.
Use the pictures/overheads and video to lead a discussion on similarities
and differences in cephalopods, possibly focusing on the information
provided in Background Information (see above). Depending
on your students’ prior knowledge, your introductory presentation
on cephalopods and chromatophores can be adapted to meet the interests
of your class.
Before starting the activity, ask students to discuss what cephalopods
might try to communicate using their chromatophores. The activity
focuses on predator avoidance, mate recognition, and prey capture,
so it is necessary to discuss these particular communications in
your presentation. Because this activity focuses on cephalopods’
use of non-verbal communication, discuss other types of non-verbal
communication, such as sign-language and body language.
Procedure for the Activity
(We based this activity on a classroom size of 30 students, but
it can be adapted accordingly based on your class size.)
- Divide 20 students into 5 groups of 4. Depending on your
class size, groups should range in size from 2-5 students.
- Gather the remaining 10 students together in one area.
You will be assigning them roles for the activity later.
- Give each of the 5 groups four different colored pieces of
construction paper (e.g. each group will get one piece of red
paper, one piece of blue, one piece of yellow, one piece of green).
- Each of the 5 groups needs to select a group leader.
- Explain the basics of the activity to all the students.
The 5 groups will be cephalopods (specify a particular type of
cephalopod). The remaining 10 students will be designated
as predators, prey or cephalopod mates. However, only the
group leaders will know which of the students will be predators,
prey or mates. Using the different colored construction
paper, the leaders will need to navigate their group through the
classroom. They must avoid the predators while finding a
mate and capturing a prey. Inform students that during the
actual game, they will not be able to talk and will only be able
to communicate by signaling to each other using the construction
- In their groups, the students should decide what they want
each color of construction paper to signify. It is up to
the students to decide how to use the paper; they do not have
to use all colors.
- While the groups are discussing, designate the remaining 10
students (from step 2) as predator, prey or mate. For a
group a 10, we chose 2 predators, 4 prey and 2 mates. Decide
on a specific type of predator and prey that would be appropriate
to the chosen cephalopod (sharks (predator) and shrimp (prey)
work for most cephalopods).
- Keep the group leaders, predators, prey and mates inside of
the classroom while you briefly send the other cephalopod students
out of the classroom.
- Tell the group leaders which of the students are predators,
prey and mates.
- Those students who are predators should find a place in the
classroom from which they cannot move their feet during the actual
game. They can, however, extend their arms to try to catch
the cephalopods. The prey and mates also need to find a
fixed spot in the class; however, once they are discovered by
a cephalopod, they can move with that group.
- The group leaders need to stay in one spot where their group
will be able to see their signals.
- Let the cephalopod students back into the classroom.
Explain that from this point on there will be no talking.
Each group will need to stick together and will need to pay attention
to their group leaders who will signal to them from their spots
to show them which students they should avoid (predators) or try
to find (prey and mates). Tell them to carefully observe
their group leaders because predators will be able to extend their
arms and if a predator touches them, their entire group will be
eliminated. It is also possible to eliminate just those
cephalopods touched by the predator, which allows the remaining
group to continue.
- Let the game run 5 minutes, or until all prey and mates
have been captured by the groups.
- After the activity, have students return to their seats for
- Immediately after the activity, before discussion questions,
it is interesting to discuss the results such as which groups
were most successful or unsuccessful and what the groups used
the colors to mean.
- The activity can be repeated which should allow students to
get increasingly better at using the colors to communicate.
work sheets, additional web pages
All images can be used for educational purposes.
Two Pacific Reef Squid, Sepioteuthis lessoniana, photographed at
night in the Red
The Red Octopus, Octopus rubescens.
The chambered Nautilus, Nautilus pompilius. This specimen was trap
caught at depths
of 200-300m in the Phillipines.
A courting pair of European Cuttlefish, Sepia officinalis. The male
guarding the female (background) from other males. These are
fully mature animals at
about one year of age. Note the bold zebra-like striping typical
of this species.
for discussion or conclusion
- What are some of the problems that you faced in communicating
during the activity?
- What is an adaptation that cephalopods possess to aid in their
communication and why is it an advantage for them?
- What types of things do cephalopods express using their chromatophores?
- What are some other forms of non-verbal communication?
|The lesson should introduce
students to the different species of cephalopods (octopus, squid,
cuttlefish, nautilus) while discussing the differences and similarities
between these species. Focus on the ability of the cephalopods
to communicate using chromatophores. Chromatophores are pigment
changing cells that are controlled by the cephalopod’s nervous system.
Changing colors allows cephalopods to conceal themselves from predators,
remain hidden while hunting prey, and signal to other cephalopods.
The activity focuses on using color as a form of non-verbal communication
and allows students to develop their own system of communication.
|Use the discussion questions to
initiate a discussion of cephalopod communication in order to assess
if the students understood the significance of non-verbal communication
and the function of chromatophores.
activities which relate to and extend the complexity of the experiment.
|Students could research a cephalopod
of their choice to learn more about the functions and adaptations
of the animal. Students could also research other types of animal
communication. See other types of activities focusing on cephalopods
A web address with information on the topic of the activity.
Castro, Peter and Michael Huber. Marine Biology. 3rd ed. Boston: McGraw
Incredible Suckers (video). Nature, 1995. PBS.
Moynihan, Martin. Communication and Noncommunication by Cephalopods.
Bloomington: Indiana University Press, 1985.
The Octopus Show (video). Nature, 2000. PBS.
The Ultimate Guide: The Octopus Video (video). Discovery
for information on ordering Nature