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 t