Utilization of Invertebrates in Breathing Experiment and Observation for the Sixth-grade-science

Abstract

The purpose of this research is to give students better understanding of respiration that breathing by the lungs is not the only way of respiration and some invertebrates whose mouths and noses are indistinct respire without mediating the lungs.

The present authors devised some methods for students'experiments to confirm

that invertebrates discharge carbon dioxide.

1. It was detected that Incilaria fruhstorferi respires through the parts except its

mouth by soaking it in a Bromo Thimol Blue solution. The color of BTB solution changed from green to yellow by carbon dioxide expired from the animal. This color distribution of BTB solution was fixed by animal mucilage.

2. We developed the method to check at the same time animals such as Geothelphusa dehaani living at the border of water and land discharge carbon dioxide into the water and the air.

3. The students understood visually that Pheretima communissima was struggling to demand the air.

4. Shapes of shellfish are quite different from fish. So the students are convinced that it might not breathe. But they could understand that it discharge carbon dioxide as same as fish.

By making experiment with invertebrates as above, in addition to mammals and fishes, the students understood that breathing is the common activity for living in all animals including invertebrates.