From the Grade 7 Science IRP's:

Compare and contrast asexual and sexual reproduction in both plants and animals

Describe the growth and changes in the development of an organism

Objectives:

1. The student will be able to point out the differences between the three and four phase life cycles of insects.
2. The student will be able to explain the life cycle stages of a leech and a scud.
3. The student will be able to explain how mayflies mate and reproduce.
4. The student will be able to explain how leeches mate and reproduce.
5. The student will be able to compare and contrast the mating procedures of leeches and mayflies.

Materials Needed:

• Computers
• Overhead projector
• Student notebooks
• Aquatic Fish Foods Worksheet #S-4a (Three and Four Phase Life Cycles)
• Aquatic Fish Foods Worksheet #S-4b (Leech and Scud Life Cycles)

Activity:

For this Activity students will need to have access to the Insect life cycle, Leech, Scud, and Mayfly information presented in the Aquatic fish Foods section of www.kidfish.bc.ca . These pages can be printed out, photocopied, and put into booklets, or students can work directly off any school or home computers that have internet access.

Hand out the "Aquatic Fish Foods Worksheet #S-4a (Three and Four Phase Life Cycles)".

Make an overhead copy of the diagrams for yourself in advance. Go over the information for each of the Life Cycle patterns as discussed in the Insect Life Cycle section. Next, in their notebooks, have students list the following six aquatic insects: Midges, Caddisflies, Waterboatmen, Damselflies, Dragonflies, and Mayflies. Have the students research which life cycle pattern each insect has and put this information down by the name of the insect listed in their notebook.

Hand out the "Aquatic Fish Foods Worksheet #S-4b (Leech and Scud Life Cycles)". Go over the information for the Life Cycle patterns as discussed in the Leech and Scud sections.

Next have a discussion with students taking notes. Discuss the mating and egg laying procedures of leeches and then mayflies. Use the information found under the "Life Cycle" sections of these Aquatic Fish Foods as a guide. Especially contrast the hermaphroditic qualities of a leech compared to the male or female qualities of a Mayfly.

On a separate sheet of paper have the students write a short paragraph that points out some differences that they have noted. This activity can be organized as an individual, group or class wide activity depending on teacher preference.