Hermit Crab Unit:  What are the parts of the hermit crab?

 

Teaching method:  This lesson is based around the ideas of guided inquiry.  Students will be observing and drawing the hermit crabs on their own.  They will then choose a type of hermit crab to investigate further.

 

Contextual items:  Skill building lesson for students to practice their observation and diagramming skills as well as the skill of using a hand held lenses to make closer observations.  Students will also have a chance to revisit the internet and learn more about different varieties of land hermit crabs.

 

Time:  1 hour

 

Prerequisite knowledge:  This lesson should be completed after reading the two books (A House for a Hermit Crab and Pagoo).  Students should be familiar with the different types of hermit crabs and now be ready to focus in on the land hermit crab and its varieties. 

 

Goals and student objectives:  Students will practice using a hand lenses to make observations.  Students will draw a hermit crab in their science journals and label its body parts.  Students will then choose a hermit crab to research on the internet using the website: http://www4.tpg.com.au/users/vanessap/hermit/biology/anatomy.html.

 

State standards:  11.A, 12.A

 

Materials:  4-5 hermit crabs, a classroom poster of the parts of a hermit crab, a hand held lens for each student, a computer work center with internet access, science journals for each student, a poster sized drawing of a hermit crab missing the labels

 

Opening activity:  Begin by introducing the class to the hand lenses.  They may or may not have worked with these before.  Instruct students that they are to use the lenses to get a more accurate view of the hermit crabs.  Make sure students know how far to hold the lenses from the crabs and how to properly handle the lenses.  It would be ideal to have more than one hermit crab available.  The teacher may want to take each crab out of the cage and set them in the middle of the desk, this way they will be more likely to actually walk around and reveal their bodies. 

 

Procedure:

  1. After students have had a chance to observe the crab, they should begin drawing what they saw in their journals and taking notes.
  2. It will be difficult for them to be able to view all of the crab at once, as it will be in its shell.
  3. Have students then take turns going to the computer work center and looking up the parts of the crab online at the given website. 
  4. This website has a detailing drawing of the parts of the hermit crab with labels.
  5. Students should copy this drawing into their science journals.
  6. Next, students may research a crab of their choice using the website.
  7. Come back together as a class with a poster sized drawing of an unlabeled hermit crab.
  8. Have students label the hermit crab as a class.

Assessment:  Take note of the how the children did using the hand lenses.  The final assessment should be based on the class’s ability to accurately fill in the correct parts of the hermit crab on the poster.