Organisms
Lesson 7
Observing Freshwater Snails
The focus shifts from plants to animals. The freshwater snail will be introduced into the freshwater habitat.
3. Lesson set up and Management
INQA Scientific investigations involve asking and trying to answer a question about the natural world by making and recording observations.
INQC Scientists develop explanations, using recorded observations (evidence).
INQD Scientists report on their investigations to other scientists, using drawings and words.
INQF All scientific observations must be reported honestly and accurately.
SYSA Living and nonliving things are made of parts. People give names to the parts that are different from the name of the whole object, plant, or animal.
LS1B All plants and animals have various external parts.
LS1C The parts of a plant or animal appear different under a magnifier compared with the unaided eye.
LS2A There are different kinds of natural areas, or habitats, where many different plants and animals live together.
LS3A Some things are alive and others are not.
LS3B There are many different types of living things on Earth. Many of them are classified as plants or animals.
LS3C External features of animals and plants are used to classify them into smaller groups.
- Student will observe, draw and describe freshwater snails to understand characteristics of animal organisms.
- Students will develop an understanding of what pond snails and other animals need in order to live.
3. Lesson set up and Management
Materials:
- Snails and guppies should have been ordered with at least 20 days prior to this lesson. Be sure to let the office know to be on the lookout for a Live Materials order and open the box immediately.
- See to the needs of the snails immediately. During shipping they may have contaminated the shipping container to near its maximum capacity. Rinse the snails off in conditioned water which you have kept on hand and place them in a holding pail of conditioned water.
- Do lessons 7 and 8 as soon as possible to ensure that the animals are in good condition for observing.
- Two pinches of fish food will probably last the snails for a week.
- If a snail is floating or lying on the bottom for a period of time pick it up. If it retracts into the shell it is alive if not, discard it.
- Put one snail in about 1/3 cup water so that each team can have two to observe.
- It is a good idea to have aged water on hand for this and other live organisms. To age water, fill a gallon jug and allow it to sit with no lid for 24 or more hours. This will allow chemicals in the water to dissipate.
- If the teacher is having students write directly in the science notebook rather than on Recording Sheet 7-A make a line halfway down the page and use the top half for recording about the snail and the bottom half for recording about the guppy in the next lesson.
- Teachers may opt to use the box & T-chart instead of a Venn diagram. It is easier to use for the guppies side as well as the snail side and the box is an easier way to deal with the “same” piece than the intersection of the two Venn diagram circles.
- The Management Tip in the Organisms Teacher’s guide discusses maintaining the aquariums if they must be left unattended for a period of days. The fish and snails are pretty tough and usually do fine if left for up to a week.
Students should handle snails only
very briefly.Sometimes it is easier to observe snails
out of the cup.Students can record observations and
labeled diagrams in their science notebooks
instead of on the record sheets from the
unit.
Student Management:
- Put one snail in about 1/3 cup water so that each team can have two to observe.
- A good rule with living organisms is to "Look but don't touch." However, students can briefly hold the snails, keeping in mind that too much salt from student hands will damage the snails.
- Sometimes it is easier to observe snails out of the cup.
- Use the class observing table developed in lesson 2 with the pictures of the eye, nose, ear and hand to remind students how to observe.
The class observing table will remind
students how to observe organisms.
- It is quite difficult for students to see and understand the parts of the snail. In Lesson 7 of the Organisms Teacher's Guide is a diagram of a snail which is useful to show as an overhead to the class pointing out what they might observe before they look at the snails.
- Teachers may want to look ahead at Lessons 11 and 12. These lessons call for some observing and writing about the aquarium which they may wish to do as they move through the lesson to which it directly pertains.
- The Organism Teacher's Guide provides some bulleted questions. The bulleted questions should be part of the ongoing, running dialogue in which the teacher engages as students observe the snails. These questions include: What did you find out about the snail? What are some words that describe the snail? What is the snail’s body like? What did you find out about the way the snail moves? What did the snail do while you were observing it?
- Snails are gastropods, which means "stomach-footed". They are "invertebrates," which means they have no bones like we do. Talking about these science words and their meanings with students can provide some rich vocabulary experience.
Writing Support:
- There are blackline masters of each of animal provided in the Organisms Teacher's Guide. Their suggested use is to color two and staple them together and stuff them with paper towel or batting. These "stuffed snails" can make great classroom mobiles. Add lines and they become great creative writing or poetry writing paper.
Reading Support:
- Read Snail's Spell by Joanne Ryder. Then have students act out the passages describing what it feels like to be a land snail and have them act out the role of a water snail.
- A book students can read independently is Snail by Sandra England.