Materials
> Container of shells.
> Laminated cards of:
 Gastropods
 Bivalves
 2 sets of “What am I?” cards (one for oyster, clam and scallop)
For younger children, use cards with bigger letters and “dots”
Follow-up Activity
Shell Identification Activity
(oyster – clam – scallop comparison)
The Shell Identification Activity is designed to help students learn to
identify shells from the Mollusk phylum’s Gastropod and Bivalve
classes. The activity is ideally designed for explaining taxonomy to 5th
and 6th grade students but includes ways to expand the activity or
incorporate it into another lesson.
Activity
“What am I?” cards:
1. Look at picture on front of the card, and at the real shells.
2. Guess which bivalve it is (oyster, clam or scallop?)
3. Flip card over for answer and learn about bivalve facts.
“What are we?” cards:
Flip card over & learn about bivalves or gastropods.
> Younger kids:
Ask them to act like an oyster, clam or scallop that detects
danger.
How does the oyster, clam or scallop deal with the situation?
Answer: oyster shuts it shells
clam digs in deeper
scallop quickly swims away
> Older students:
Use bivalves to discuss habitat adaptation. Extension: smart
coping skills in general
Note: Activity can be used as part of table top display.
- Not heavy to transport and doesn’t take up a lot of space.
- Do-it-yourself activity; doesn’t require prior knowledge of
booth attendant.
I am an OYSTER

I live in the same spot most of my life.

I live stuck to a hard surface, above the sand or mud.
I would choke in the sand or mud.

I eat tiny, tiny plants you can only see with a microscope.

When I eat, I relax my big muscle, opening my shells and
drink the water I live in because the tiny, tiny plants I eat
also live in this water.

When I am scared, I close my shells to protect myself.
I am super strong! When I flex my muscle, almost
no one can open my shells.
.
I am a CLAM

I live on the bottom of the ocean and rivers.

When I am scared, I flex my muscle, close my shells
and dig into the sand or mud with my foot.
I am a fantastic digger! Almost no one can find me
when I hide.
.
I am a SCALLOP

I live near the bottom of the ocean or bay.

When I am scared, I flex my muscle, open and close
my shells to squirt out water, and use my foot to quickly
swim away. I am a fantastic swimmer and escape artist!
OYSTERS
Oysters start as eggs. Then they are planktonic and float for about
3 weeks. They grow quickly. Young oysters develop a “foot” and
swim looking for a good, hard surface on which to live; often on
other oysters, forming oyster beds. They become sessile and
live in the same spot the rest of their lives.
To
assure the survival of their oyster bed
population, they are hermaphrodites. They can change sex back
and forth from male to female.
As spats, teenagers, young oysters cement to a hard surface
because they would choke in the mud or sand. Oysters are filter
feeders. They eat phytoplankton, tiny plant matter floating in
the upper layers of the water column. This plankton, like all plant
matter, gets its energy from sunlight.
An oyster’s defense mechanism is to flex its very strong adductor
muscle and close its bivalves, two shells, really tightly.
.
.
CLAMS
Clams live in the benthic zone, the bottom of the ocean or river.
Cape May Lenni Lenape Native Americans first made wampum
from the white and purple inside of clam shells (mother of pearl).
A clam’s defense mechanism is to clam up! It closes its bivalves
(two shells) flexing its adductor muscles that hold the shells
tightly closed, and dig with their foot into the sand to hide.
.
.
SCALLOPS
Sea scallops are much bigger than bay scallops.
A scallop’s defense mechanism is to flex and relax its very strong
adductor muscle that opens and closes their bivalves, two shells.
A scallop rapidly escapes the danger zone, squirting out water and
using its “foot” to steer.
What am I ?
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What am I ?
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What am I ?
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What am I ?
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What am I ?
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What am I ?
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What are we ?
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What are we ?
Bivalves = 2 shells
Class:
Phylum:
Kingdom:
Bivalvia (bivalves)
Mollusca (mollusks)
Animalia (animals)
Valve means shell
Bivalves






2 shells
hinge that attaches the shells
adductor muscle(s) that close the shells
a “foot”
aquatic
live in salt, brackish and fresh water
filter feeders; select food particles out of water
.
Wikipedia
.
Gastropods
Class:
Phylum:
Kingdom:
Gastropods
Mollusca (mollusks)
Animalia (animals)
Gastropods are also called univalves
because many have 1 valve. Valve means shell.
Gastropods



1 shell (e.g. snails)
or no shell (e.g. slugs)
aquatic, live in water (e.g. conch)
or terrestrial, live on land (garden snail)
herbivore (eat plants)
or carnivore (eat meat)
or omnivore (eat everything)
Wikipedia