Lesson: Molluscs: General Lesson Plan

BY: Avril Bourquin and Robynn Honeychurch

First things first! Printout and use the lesson plan checklist to assist you in making the most out of your lesson plan


Length of Lesson: Approximately 3 hours for the general lesson plan. This however, can be any length depending on the plan you choose to use or make up from the materials presented here. Their is more than enough information and additional resources presented here, that it can quite easily be split into many different lesson plans formats.

*Please note that this is an extensive lesson plan containing a lot of information and ideas. You, as the teacher should take the time to read through the following pages and determine which format and which activities will work best for you and your students.

TEACHERS:By no means try to present all the information in one lesson plan. Scan this lesson plan, then decide which lesson plan format and materials you wish to use for your class.

Lesson Plans presented in this package
Lesson Plan Format
Classroom Grade suggested
Time Length
General Lesson Plan
K through 12 3 hours plus
K - 3 K-3 1-2 hours
4 - 8 4-8 1-2 hours
9 -12 9-12 2 hours plus
Suggested lesson plans that can be created from the information found in this general lesson plan
  • Snails, Bivalves and Octopus: decide which grade level and materials are most appropriate for you. A lot of information and activities have been placed here so that you may easily personalize a lesson plan best suited for you and your class and time available for this subject.
  • Gastropods (Marine Gastropods lesson plan information is coded brown)
  • Bivalves (Bivalve lesson plan information is Coded Green)
  • Cephalopods (Cephalopod information is coded Navy Blue)


Instructional Goal
To provide students with an introduction to the invertebrate phylum, mollusca and to help them gain a basic understanding of molluscs in general.
In most of these lesson plans, three main classes will be discussed in general. Those classes are; the gastropods, bivalves and cephalopods. The main emphasis in the K to 8 lesson plans will be on the terrestrial (land snail) gastropods mainly. The 8 - 12 lesson plan will also include a discussion on the other classes. Those of the Polyplacophora, Scaphopoda, Monoplacophora and Aplacophora.

Discussions and materials presented will cover such things as anatomy of the mollusc, needs of the mollusc and procreation of the molluscs. Your students will also learn how and why molluscs are important to humans and the environment. They will also be presented with the habitat and environmental problems involved around and with molllusc.

Performance Objective
Students will create a report, including drawings and notes based on the information presented to them and the observations they make of their molluscs, shells, habitats and work sheets presented in this lesson plan.

Students should be encouraged to participate in discussions about molluscs, their value to humans and the environment and a bit on "Molluscs: Friend or foes?".

Students should also help out in making a molluscan habitat and other classroom projects (e.g. posters) based on molluscs.

Molluscs are an integral part of our environment. In studying this life form, students will observe the way these animals are a very important member of our world today. The mollusc's reliance upon the environment in which they live, and the way in which we humans rely on them, exemplifies the interconnectedness of all the ecosystems of the earth.


Lesson Content


Planning Ahead
The following steps should be taken well in advance of teaching this lesson:

  1. Print out a copy of this lesson plan for yourself to follow. Decide what printed materials will be used for your lesson and have the appropriate pages photocopied. (See the enclosed in the the lesson plan checklist)

  2. Research your locality for available resources such as, museums with shell collections, local aquariums, local shell clubs and or shell collectors in your vicinity. Often you can find someone willing to come into your classroom to present and display their shell collection. Field trips may also be planned as part of your lesson plan.

  3. Teachers should also collect some shells to share with their students. Do this a few weeks before you first lesson. Check your local museums, ask friends, look for shell clubs in your area. Many people collect shells and may have some to lend you.

  4. Several weeks before your first Mollusc lesson, encourage your students to look for shells of all kinds. Perhaps their relatives or friends will have shells which they are willing to lend out. Place each student's contribution in their own labeled bag, so that shells can be returned to the rightful owner after the completion of the lesson.

    If you live by the seashore, lakes, rivers or other bountiful snail and slug areas,encourage students to bring in their own shells to class. Make sure these shells are clean and not inhabited or filled with decaying matter (soaking shells in a bleach and water solution used under strict adult supervision, cleans up most shells). Unshelled molluscs such as slugs should be placed in an air tight jar filled with rubbing alcohol. These shells should also be placed in bags and labeled with the students name. You should also encourage the student to place a paper with their find as to where the shell was found the date it was found and if it was alive or dead when collected. Have them write down as many details as they can in regards to their finds. If they become a shell collector, collection data slips help to increase the educational and economical value of their collection.

    *** Be sure to heed this, and share this with students: if shells are brought from far away, make sure there is nothing living in them! Clean out the shells before they leave their place of origin. The propagation of misplaced molluscs can cause serious environmental and ecological damage!

  5. If in your lesson plan you are going to include living snails in a terrarium or aquarium; be sure you have the appropriate food, water and other necessities such as a calcium source available for feeding the snails that you will collect and house.. Have your snail's terrarium or aquarium created BEFORE you collect or purchase your snails. (See the habitat preparations in the next section).

  6. If you plan to use garden snails for your students to observe, plan to collect them well before you want to use them in the classroom. Sudden changes in the weather can send an apparently plentiful supply into hiding so that none will be available. This is also good advise if using live freshwater snails.
    Often live terrarium or aquarium snails can be purchased at pet stores. See details of collecting and looking after snails. (See the habitat preparations in the next section).

  7. If teaching younger children, be sure to print out "Sammy's Adventure" story, and any additional worksheets , colouring sheets, etc. that you plan to use (see the lesson plan checklist). All materials found on this lesson plan are the property of Man and Mollusc and are not copyrighted for educational use and can be freely used for all educational needs. The exception is "Sammy's Adventure". This story is copyrighted but may be used freely for all classroom lessons. An illustrated "Sammy's Adventure" story book will be published within the next year (2002). To learn where and when this book will be available, check with the owner, Avril Bourquin: avril@rockies.net

  8. Optional: A few weeks before you teach this lesson, check through some of the sites listed on the Additional Resources section at the end of this lesson plan. There are extra more games, puzzles, pictures and much more information about molluscs that you may wish to use.

  9. A few days before your first class, search out books at your school or community library on molluscs to bring into your classroom and share with your students. Bring as many of your School Library books on molluscs to your class as possible. This way students will know what to look for in their own school library.

    Optional Ideas that take some preplanning

  10. Escargot (canned) can usually be bought ahead of time at most grocery stores and can be brought in to class to show students an example of edible terrestrial snails. For class use; open a container of escargot, wash and place them in a clean container filled with rubbing alcohol. Replace alcohol, as needed, when it begins to go brown.

  11. Oysters, clams, scallops and mussels can usually be bought ahead of time at most grocery stores or fish markets to be preserved for class as well in alcohol or formaldehyde.

  12. Living marine molluscs can also be purchased or found nearby if you live at the ocean and these may be kept in a saltwater aquarium and kept alive for the classroom (see habitat info in next section) . Use local beach water for these specimens unless you are used to maintaining a salt water aquarium. This water must be replaced regularity and an aeration stone is a must. I would only encourage you to keep such living specimens for one day only unless you are proficient at salt water aquarium keeping. Plan to return these to their original home.

  13. If you are a really ambitious and creative teacher you may even decide to cook up a seafood meal for your students as an introduction to this mollusc unit. Parents may be of help in preparing a seafood or molluscan feast . Notes sent home with a student well in advance of this lesson may help you to present the idea and help you locate volunteers.

  14. A field trip could be planned to search out molluscs and to observe them in their natural habitat. Seashore rock pool or tide pools, lake shores creeks, and rivers make an excellent field trips.

    A word of advise: visit these areas well in advance of taking your students so that you know for sure where to locate snails. If going to a beach, be sure to know what the tide status will before this day as well. Tide and rock pools may totally disappear if you have a high tide. Also be sure to have adequate supervision for all students if undergoing such a field trip. Once again, check whether or not you have a local shell club which might be of help to you on such a trip and if their are collecting bans or bag limits.

  15. Museums or aquariums with a focus on sea life or molluscs can also make a good field trip destination for this unit. Often if you speak to the curators of such facilities, special arrangements can be made to have a special displays and onsite talks for your class. Give these people as much time as you can for arranging such a visit.


Materials and Aids

  1. Make sure to have a copy of the lesson plan checklist
  2. Copy of the general lesson plan and if using one of the other plans, copy that out as well
  3. Rubbing alcohol and or formaldehyde and jars with tight fitting lids for preserving any living tissues to be used for the classroom
  4. You may want to bring a jug of strong bleach water to class to clean any shells requiring extra cleaning
  5. Bags (Zip locks work great!) and a labeling pen for storing the students' shell contributions
  6. Collected shells (found by students or teacher or both). Make sure they are well contained and labeled as well so they can be returned to the rightful owner on completion of this lesson.
  7. For younger children: "Sammy's Adventure" story (see the the lesson plan checklist)
  8. Colouring pictures (see the the lesson plan checklist)
  9. Printed handouts on molluscs for students (see the the lesson plan checklist)
  10. Miscellaneous sheets of coloured paper
  11. Blank paper, pencils and erasers for drawing snails and recording facts
  12. Crayons and or pencil crayons for colouring pictures and drawing snails and shells
  13. Scissors for children's use
  14. Glue or glue sticks
  15. Large Bristol board for making a class poster
  16. A piece of glass or Plexiglas about 6 by 12 inches with well taped edges for safety.
  17. Terrarium, aquarium or other habitat containers
  18. Snails, plus their correct food and water source. Keeping a living exhibit is discussed in the next section of this plan
  19. Shells
  20. Library books


Making a terrarium habitat: This can be kept as simple as a jar or as complex and imaginative as you and your students wish. These are just guidelines.

Active snails can be kept for classroom viewing in a terrarium made from an aquarium, a large, wide-mouth jar turned on its side, plastic tubs, fish bowls,etc. The top should be securely covered with a fine meshed nylon screen or part of a nylon stocking. Lids which have holes punched in them do not allow for adequate ventilation and the sharp edges on the interior are a safety risk to both snails and students.

To collect terrestrial snails, you will need a shovel and a container (to put your snails in). Make sure your container is not airtight so that the snails can breathe by making tiny holes in the lid. Use a plastic container to avoid sharp edges. (You need a lid to cover your container because snails can crawl on any texture or surface.)

To find the snails; choose a damp spot such as, under leaf litter or near a pond. Use your shovel to loosen the ground and you should find many snails just beneath the surface. Be sure to collect some of the soil or leaf litter for use in your terrarium.

Terrestrial snails may be collected around gardens and in trees in your own area. Be sure to locate these snails well in advance so you know where to find them for your classroom. Looking for them at night time is best as most are nocturnal and or like to like in dark damp places so that they don't dry out so fast. Be sure to know what they eat and collect as much food from their natural environment as possible to include in your terrarium. Non-clohorinated or natural (Rain, lake or stream) water is also a must, so collect enough for the entire time you plan to keep your snails. Herbivores also will generally enjoy lettuce broccoli, fruits etc.

Keep the terrarium clean and food and water supplies fresh and clean. Plan to release these snails back to their original home upon completion of the lesson. If they are a known pest, you might well have them properly destroyed and keep the shell for future class use.

In your terrarium, drinking water can be supplied in a shallow dish, plastic lid or in a deeper dish containing a water soaked sponge, or by generously sprinkling lettuce or other fresh, leafy food with water. Create a sample habitat by including damp soil, or sand, plants, and rocks preferably from the snail's original habitat.

Food can also be placed into a shallow plastic lid in the terrarium. Most terrestrial snails are vegetarians and eat many kinds of plant material. Cornmeal, oatmeal, and fresh green leaves (Lettuce, broccoli, fruit, etc.) are all appropriate foods. Chalk, a cuttlefish bone from pet store (NOTE: this is a mollusc) or eggshells should be placed into the terrarium to provide the calcium necessary for healthy shells. Snails need calcium for healthy strong bones, much as we need calcium for strong, healthy bones.

Cleaning to remove stale or moldy food, the build up of mucus, and droppings, should be done on a regular basis. Water should also be kept clean and fresh. Encourage your students to help with this chore.

Snails which withdraw into their shells during class can usually be coaxed out by a brief dip in a shallow container of water.

Overcrowding snails should be avoided. In terrariums, too many snails in too small a space, or inadequate ventilation can cause the humidity to rise to unacceptable levels and the snails will die.

If time permits, (are you keeping the snail for a few weeks or more), the lifecycle of the snail can be observed in the classroom. Adult snails can be recognized by a small lip that is added to the open end of their shell when growth is complete.

Most terrestrial snails are hermaphroditic (each snail had both male and female sex organs), any two snails can mate. Each fertilizes the eggs of the other. The eggs are usually laid in a hole that the snail digs in the damp soil or under bark or damp leaf litter The small, translucent white eggs about the size of small peas.

Upon completion of your lesson, plan to return all snails to their original home. If they happen to be a known pest species, they may be disposed of appropriately and their shells cleaned and kept for future lessons. Soft parts may also be kept in formaldehyde or rubbing alcohol.


Make a Freshwater Aquarium Habitat: This can again be kept very simple or as complex and fancy as you wish to be.

For freshwater snails, search along the lake shores river or creeks. Be sure to look under wharfs, stones and on water plants. Use a fine meshed collecting net to retrieve snails. Be sure to collect a good supply of the water the snail is found in. This is the best way to make sure the snail remains healthy. Use only this water (you may add an aeration stone, and filter system to keep the snails healthy and happy. Rocks covered with mosses and algae found around the snail should also be added to the aquarium. This aquarium should also have a lid or stocking cover as pond snails sometime do crawl out of the water.

Aquariums, large glass jars, fish bowls or any solid water proof container can be used. Just make sure it has a fine meshed top or stocking top for a lid. Molluscs are great escape artists.

You may have a fully water-filled aquarium or just a pool of water around such things as rocks and old tree branches from the area where you found the snail. This allows the snail to crawl on and up out of the water. An aquarium lid or mesh top to prevent escapes is still a vital part of this setup.

Be sure to return all living snails to their place of origin or have them properly disposed of, if they by chance are a known pest species, at the completion of your lesson.


Saltwater Aquariums:

Unless you are just keeping a salt water habitat for a few hours, it is best to have a well established saltwater aquarium or at minimum a lot of replacement water from where you caught the molluscs.

Sometimes salt water molluscs can be found at a pet stores or if you live by the ocean, they may also be collected on the seashore around rocks in the inter-tidal zone.

Be sure to collect a good supply of the water where they live for your aquarium. These molluscs should be returned back to the ocean ASAP as they will not survive long in a simple aquarium. You should also collect a few rocks, sea weed and a bit of bottom sand or detritus to add to your habitat.

If you are going to use an established salt water aquarium, I would strongly suggest that you understand the basics of maintaining such an aquarium. Another option would be to have a knowledge person placed in charge of your aquarium for you. Check at your local pet shops for such help.

If self-collecting molluscs, be sure to know and observe local collecting bag limits and restrictions. Usually this can be found out a government offices. Permits to collect may also be required.


Salt Water Tide Pools:

If you live near the ocean, you may wish to set up a classroom tide pool. Collect molluscs, rocks, algae, sand, water weeds or whatever else you find in the natural tide pool . Be sure to check with the authorities on legalities of live collecting and disturbing a habitat. If you explain that it is a school project, and that everything will be returned to it's original place after the lesson, there is generally no problem.

Something like a large plastic Rubbermaid container or baby bath makes for an excellent tide pool.

Make sure you collect lots of water to keep it fresh and well aerated. You may also use an aeration stone however, the water still becomes fouled very quickly. Artificial tide pools should only be kept about 24 to 48 hours unless you are familiar with caring for such a habitat and know what molluscs you have and what their needs are.

Again, make sure you have a good mesh cover as these molluscs also love to wonder about especially if you happen to have picked up a shell inhabited by a hermit crab..


Teaching Procedures

  1. Teachers should encourage students to share what knowledge they already have about molluscs ahead of actually starting the lesson. Have students bring in shells and bag and label them as discussed above. This may be done any time before the beginning of the actual lesson plan.

  2. Teachers may have the students help to set up a live habitat or do something like a diorama ahead of the actual lesson as well.

  3. Teachers should read "Sammy's Adventure" to younger students (also enclosed in the the lesson plan checklist), first instructing students to listen for the facts about snails that are hidden throughout the story.

  4. Teachers should ask students what they have learned about a snail from this story or about other molluscs from materials you present

  5. Students will be asked to carefully observe the molluscs in their habitat (the terrarium or aquarium or other habitat that the teacher and they have set up). Send students up in small groups to study the habitat, while the other students remain in their seats and record, in note form on the same sheet where they will draw their snails, the facts they've learned about snails from the story they heard.

  6. If there's time and you're using terrestrial or pond snails, teacher can remove several snails from the habitat, and place them on moist surface such as a big leaf from a head of lettuce to also observe then move about and eat.

  7. Encourage students to gently touch and pick up the snails so that they can closely observe their colours, shell pattern, body shape, size and texture.

  8. Have the students carefully place the mollusc onto the piece of prepared glass so they can observe the snail moving. A small bit of cornmeal or cornstarch can also be placed on the glass and you might actually see the mollusc feed by using it's radula. Small scratch marks will be left visible if they do feed. Remind students that they will be returning to their seats to do a detailed drawing of the snails they've observed. Have students also observe the contents of the habitat as well , so that they can draw these in as well.

  9. Upon returning to their seats, students should draw the molluscs in its habitat from memory, and write any additional facts or observations that they have made from observing the snails. Encourage students to draw in as many details as they can: including the foot, tentacles, eyes, body and shell of the mollusc, plus whatever else is in their habitat to keep the snail alive and happy.

  10. Handout the snail diagrams, other work sheets stories or quizzes that you plan to use for students to study and label.

  11. Be sure to cover such facts with your students such as:
  12. Teachers should encourage students to brainstorm:
    (If desired and have them prepared, hand out the pages on Introduction to Molluscs, Cephalopoda, Bivalves, and Gastropoda. These pages are from Man and Molluscs Beginner's (and are also enclosed in the the lesson plan checklist)

  13. Discuss what other sea creatures and land beasties can your students think of that might be molluscs? (be sure not to get mixed up with such things as starfish, sea biscuits and sand dollars etc., which are echinoderms) (Ex: slugs, nudibranchs, sea butterflies, nudibranchs, etc.)

  14. What do your students think molluscs eat? ( you may want to talk about herbivores, carnivores. Omnivores and parasites if the age group lends to this. Filter feeding bivalves to the hunting carnivores such as fish-eating cone shells may be touched upon here as well.)

  15. What do molluscs need to live? (food, moisture, and a clean oxygen supply)

  16. Can students think of ways in which humans use molluscs? And their shells?
  17. What do your students think happens when the environment (ocean) where molluscs live becomes polluted: like with an oil spill or when sewage from homes or industrial pollutants and garbage gets dumped into the earth's water systems?
    Ballast water from ocean liners is also another danger to ports. This is how such things as the zebra mussel got into the Great Lakes where they have created massive damage.
    Snails moved from one habitat to another may become bad pests and devastate crops and other vegetation.

  18. Discuss with your students what happens when the environment is disrupted due to lack of molluscs that were once present or when new introduced species overruns an area.
    Animals and man that feed upon this mollusc are losing a food supply. Where invasive molluscs go, food supplies that other rely on are jeprodised and or crops may also be destroyed. How does all this affect man?
    What happens to terrestrial snails when their habitats are destroyed? Tree snails in areas of deforestation, or freshwater molluscs when their marshlands are drained, or chaparral areas that are torched, or beaches that are restored by dredging sand where molluscs normally live(both where the sand is collected and where the sand is dumped).
    There are many great environmental ramifications that can be studied about and discussed with your class in this area.

  19. Age level and time permitting, you may even want to touch upon some ways in which the medical world is presently studying molluscs. Such things as pain killers, cancer cures, skin adhesives for operations and materials for healing broken bones are just a few medical objectives being developed from molluscs.
    Ancient and traditional medicine use many molluscs for their curative powers.
    Medically, molluscs are also responsible for spreading many illnesses such as schistosomiasis. More information on Molluscs and Medicine can be found on the Man and Mollusc site at: /links_medicine.html

NOTE: Students can write down additional facts on the report they are creating about snails, as the discussion progresses. Teacher should prompt for this by writing key words and ideas on the board.


General Mollusc Information That Should Be Covered:

This is a more comprehensive list of molluscan facts to cover is in the next section on" Snail Facts to Refer to When Discussing and Marking Projects":

More Snail Facts to Refer to When Discussing and Marking Projects:

More detailed anatomy and physiology facts both for beginners ( A Beginner's Guide to the Molluscs ) and seniors (The Phylum Mollusc) can be found on the Man and Mollusc Lesson Plan-Checklist for Printouts

Molluscs (Mollusks; both spellings are correct)

Gastropods: Terrestrial or Garden Snail Facts :

Achitina fulica (Giant African Land Snail)


Gastropods: Aquatic (Pond or other Freshwater) SNAIL Facts:

Pomacea bridgesi (Golden apple snail)

Marine Gastropods Facts (these are the conchs (Strombidae), whelks (Buccinidae), limpets (Lotiidae), periwinkles (Littorinidae), cones (Conidae), volutes (Volutidae), and cowries (Cypraeidae) that we mostly know)

Cypraea moneta (Money cowrie)

Bivalve Facts:

(Giant Bittersweet Clam)


Cephalopod Facts

Giant Pacific Octopus






The following Three Classes are for the more senior level of students:





  1. Have students examine the shells that have been collected for this lesson plan. With the use of books or Internet resources (like the visual identification kit) see if students can identify their finds. Have each student choose a shell to take back to his or her desk to draw. Encourage them to use colour.

  2. Students should write up a report on a selected mollusc or molluscs. This should containe both a drwned picture and written facts. Collect these molluscan reports, dreawings and worksheets to mark. This will also let you know what points they have learned and it will also help you to prepare fpr future classes

  3. Students can also make and cut out drawings once they are completed. Students can arrange these cut-out shell drawings g;ue them on to the large poster board provided.Shells can be labeled and poster displayed in class. Sample title for this is "Molluscs We Have Found."

  4. Provide students with colouring sheets to colour in class, or to take home, if there's not time in class. Discuss what colours the molluscs in the pictures would likely be (camouflage). Continue on with any additional activities that you wish to add to the unit.

  5. If time and space permits, keep the snails in their terrarium of aquariums in the classroom for several weeks. Actually, this could become a very interesting yearly class project. Have the students help in feeding them and keeping their home clean. Have them observe the lifecycles of their snails. Further report or notes and pictures should be encouraged. observations in the form of a small report about their lifecycle could be a great long-term project

  6. OPTIONAL: Man and Mollusc has a children's art and story page set up online where children may have their works of art, stories, limericks, poems etc. placed. These can be viewed fro the Children's Zone at: /kid_zone.html. To have items placed on these pages, contact Avril Bourquin and arrange for this


Evaluation Procedures

  1. Evaluate what the students have learned (glean whether or not students are comprehending and absorbing the information you are presenting). This can be done by discussing and brainstorming about molluscs with students.
  2. Mark the snail and shell drawings, and written reports to see what each student has been able to observe, learn, and record about snails, and molluscs in general from this lesson.
  3. Consider the contribution each student made to the brainstorm/discussion on molluscs, as well.
  4. Consider the ability of each student, the accuracy of their observations, and the time they each spent on these class projects.
  5. Did your students enjoy this lesson? If not ask them how or what they would suggest you change. So much can be learned from children. Never under estimate their contributions!
  6. Optional:If you have chosen to keep the snails in the classroom and have asked the students to do a follow-up report on the lifecycle of the snails, make sure to collect these and mark them based on the accuracy of their observations and the time they've put into their project.


  1. Man and Mollusc web site: www.manandmollusc.net by Avril Bourquin
  2. "Sammy 's Adventure" story by Robynn Honeychurch, Anna Palumbo and Avril Bourquin


Additional Resources

  1. Web pages: Many good educational pages may be accessed through Man and Molluscs Teacher's Zone at:
  2. A Visual Identification Kit put together by Avril Bourquin to accompany this lesson plan and can be found on the Man and Mollusc Lesson Plan-Checklist for Printouts
  3. These websites also have games, pictures and other materials you might use:

Lesson Plan Inclusions: Go to the Man and Mollusc Lesson Plan-Checklist for Printouts to use the printouts you wish to use