Mollusks Animal Study & Lapbook
created by Dianna Leigh
Slug Minit Books
What is a Mollusk?
Octopus 8 Facts
Mollusk Anatomy Tab
Snail Characteristics Petal
All in the Mollusk
Research and Lessons
Mollusks are invertebrates who are characterized by their soft bodies. Many have hard outer shells for protection. You can find mollusks in oceans all over the world; you will also find them in freshwater and on land in moist conditions. This is a huge group of animals with 100,000 different species! Obviously, you won't be able to study all the various kinds of mollusks. There are seven different classes within the group. Three of the main classes include gastropods, cephalopods, and bi-valves. While this unit focuses mainly on gastropods and cephalopods, you should at least introduce your student tob-valves.
Gastropods include mollusks who have a muscular foot at the bottom; the word gastropod means "stomach-foot." Most gastropods have distinct heads with sense organs as well as spiral shells. Snails and slugs as well as cowries and limpets are examples of gastropods.
The word cephalopod literally means "head-foot"; the foot of a cephalopod lies close to the head. Animals in this classification are the most active of all mollusks; they also have muscular sucker-bearing arms, highly developed eyes, and usually a bag of inky fluid which can be released for defense. This group includes the following mollusks: squid, octopuses, nautiluses, and cuttlefish.
Mollusks that have two movable shells held together by a toothed hinge are known as bivalves. Most bivalves live in sandy burrows or attach themselves to rocks. This group includes (but is not limited to): clams, scallops, oysters, and mussels.
The remainder of this unit will focus on four mollusks- octopus, squid, snail, and slug. Some other resources have been created in case your older student would like to research other common mollusks.
Here are some words to learn in order to understand the information presented
for the animals in this unit:
camouflage- the method or result of concealing oneself from the enemy by making them appear to be part of the natural surroundings; Concealment by
disguise or protective coloring.
crustaceans- a large class of mostly water-dwelling arthropods with exoskeletons made of chitin and paired, jointed limbs; includes lobsters, crabs, shrimps, and barnacles, characteristically having a segmented body
flexible- capable of being bent
herbivore- plant eating only
invertebrates- lacking a backbone or spinal column
nocturnal- most active at night
predator- an organism that lives by preying on other organisms
prey- an animal hunted or caught for food
What is an octopus?
The Octopus has eight tentacles that are covered in two rows of suckers. The name Octopus shows the basis of the creature’s name. The prefix octo indicates eight. Octopi can camouflage themselves in seconds. The Octopus uses it’s siphon and legs to move.
A bottom-dwelling animal, the octopus makes its home in a hole or rock crevice in shallow water. Sometimes it digs a gravel nest or forms a protective area with a pile of rocks. The Octopus a nocturnal creature. Nocturnal means it is most active at night.
The octopus does most of its hunting at night. It emerges from its rocky lair to seek crabs, crayfish, and mollusks, which are its favorite foods.
The octopus catches most of its prey by stealth. Having changed color to blend in with its surroundings, the well-camouflaged octopus will wait for prey to pass by and then seizes it with its long arms. The arms are powerful and flexible, with two rows of suckers that help it grip its slippery prey. The octopus then stuns its victim with a secretion of nerve poison. This toxin also helps to soften flesh. To stalk lobsters and other dangerous prey, the octopus squirts ink into the water to form a screen. Hiding behind the dark cloud, it creeps up on its victim and grabs it from behind.
An octopus can lay anywhere from 150 eggs from the Pygmy Octopus to 250,000 in the Common Octopus. If the octopus lays fewer eggs, it usually indicate that the eggs are larger and when they hatch will be almost full-grown. Opposed to those octopi which lay over 100,000, when they hatch they will float around as plankton for a few weeks before being able to swim on their own. Out of these 100,000+ Octopus eggs, only one or two will live to be old enough to give birth to their own young one day. After the eggs hatch, the mother stays with her eggs the entire length of time. This leads to death by starvation because the incubation period for the eggs is between 50 – 60 days.
The Octopus’s predators include: moray eels, conger eels, dolphins and sharks. The Octopus will use it’s siphon to use jet propulsion to try and escape predators. The Octopus also can use camouflage to hide from predators. As a last defense, it will squirt out a screen of black ink to give it a few seconds longer to escape.
There are about 100 species of octopus, with both the largest and smallest species being found off the west coast of the United States. The largest, the North Pacific octopus, where many of the octopus fables come from, can reach up over 30 feet from the tip of one tentacle to another and grossing over 100 lbs. The smallest octopus is the Californian Octopus, it can be found off the coast of California, and measures less than an inch.
What is a squid? Squids are closely related to the octopus. They are soft bodied cephalopods that are invertebrates. The squid only has one eye. Squids have 8 tentacles. The tentacles are similar to the octopus because they are covered in suckers. Octopi can camouflage themselves. The squid uses it’s siphon and legs to move.|
The depth of the squid’s habitat depends on the type of squid. Some squids live in the middle layer of the ocean, while some live right above the bottom of the floor. Like the octopus, the squid can see in dim light.
Squid eat fish, crustaceans and other squids. They use a parrot like beak to eat their pray. The food must be in very small pieces before swallowing because the esophagus runs through the brain.
Squids do not live a very long life, which is why females release such enormous amounts (up to 11 pounds) of eggs to ensure the continuation of their species. Squids usually spawn in groups. While most squid lay their eggs in masses on the sea bed, some squid carry a clutch of eggs to guard them. The adult squid does not live long after mating. Baby squid hatch as larvae and grow into maturity in about 3-5 years.
Squids have many predators, including humans. Other predators are: sharks, some fish, whales, and other squids. The squid has defense mechanisms like the octopus.
Squids live in oceans. Giant squids lurk in deep depths of 660 to 2300 feet under the sea, while other species like to swim about and call the middle layer of the ocean home.
What is a snail?
Snails belong to a group of animals with a soft body, called mollusks. Snails
are also known as gastropods (literally translated as stomach foot, the name
implies the structure of their body. The snail stomach lies above it’s feet.).
They have soft, unsegmented bodies which are protected by a hard shell. The body
of the snail is long, moist and slimy. The snail moves by gliding along on mucus
that it secretes.
What is a slug? A slug is very similar to a snail, the only difference is that slugs do not have shells. It is also a mollusk and is known as a gastropod. Slugs also use mucus to slide across surfaces.
The common snail favors moist environments and search for a moist home that is well shaded. You may find them under logs, leaf debris in the forest or bricks. They can be seen out and about shortly after a rain, or during high humidity.
Most gastropods are herbivores and eat fungi, dead animal material and plant matter, such as bulbs, leaves and stems.
Gastropod predators include: ground beetles, snakes, frogs, toads, turtles, birds, chickens, ducks and geese.
Slugs and snails love moist environments. You are most likely to find a slug or snail after a nice warm rain has finished! Just look by the shrubs or in the garden and you will find a few!
Slugs are considered pests by most gardeners because they feast on the crops. Gardeners are likely to use salt as a line of defense against the slug, pouring a line of salt all the way around the perimeter of the garden. Salt can harm slugs, it literally looks like they melt in front of your eyes, so they will not cross the line. Slugs are creatures of habit, following the same paths, so the salt line needs to be repeated for at least a week.
Learn tons about snails- Snail Animal Study & Lapbook
I Spy - Mollusk Observations
I Spy Octopi and Squids
Take a trip to your local aquarium, be sure to take a pencil and notepad with you. Spend a great deal of time observing the octopuses. Here are some questions to help you on your way:
1. What are they doing?
2. Did you see them eat?
3. How many are in the tank together?
4. Do you see how
long the webbing is? If you did see the octopus eat, did you notice how the
webbing helped it catch food?
local aquarium have squids? If so, follow steps 1-4 listed under octopus. If
not, then feel free to let your student be artistic and draw/color a squid from
I Spy Slugs & Snails
This is backyard nature at its best! Go outside after a cool rain for the best chances of finding slugs! You can also look under leaf debris, rocks and logs. I let my girls use tabbed index cards detailing the exploration (What did I do? What did I find? Where did I find it? Also, any other information the want to include. Maybe, a simple sketch of the slug/snail in it’s environment!) and add them to the lapbook.
NF indicates non-fiction; F indicates fiction.
Octopus by Lynn M. Stone. F. ISBN- 9781595154408
Gentle Giant Octopus by Karen Wallace. F. ISBN- 9780763617301
by Patricia Lauber. F. ISBN- 9780064451574
Squirting Squids by Natalie Lunis. F. ISBN- 9781597165136
Octopuses and Squids by Mary Jo Rhodes. NF. ISBN- 9780516253503
The Snail and The Whale by Julia Donaldson. F. ISBN- 9780803729223
Snails by Peter Murray. NF. ISBN- 9781592966509
The Adventures of Snail at School by John Stadler. F. ISBN- 9780064442022
Some Smug Slug by Pamela Duncan Edwards. F. ISBN- 9780064435024
Slugs by Anthony D Fredericks. NF. ISBN- 9780822530411
You Tube Videos
There are several examples of the intelligence and wonderous behaviors of the octopus online. I found quite a few videos through You Tube. My favorite links are below. Please don’t scroll through the comments as some are very rated R, and be sure to preview the videos before showing to your students.
1. Octopus escaping through a 1 inch hole
2. Wild Chronicles
3. Showing Camouflage
Paper Mache Octopus
This is messy, but so much fun!
Flour and water
pan and a stirrer
Green tempera paint
Green crepe paper streamers
TADA! (You can also make a squid paper mache by using the long ‘clown’ balloons instead of the round one used above.)
Slug and Snail Art
Have your child
use air hardening clay to mold a slug and a snail. After the artwork has dried
according to the package directions, have the child add an artistic flair!
Take pictures of your crafts and post them on one of these frames or on this octopus frame. Cut out and add to your lapbook!