A couple of weeks ago, I found the cutest little leaf sheep. A sea slug that looks adorable and who has the most amazing ability – an animal that can rely on sunshine for its nutrition.
It sounds like a test from school and you would definitely fail if you ticked that genes from an algae should work inside an animal cell. But the leaf sheep, Costasiella kuroshimae, is the most unusual sea slug that can photosynthesize. The slug is only a couple of millimetres long and found near Japan, Indonesia and the Philippines. The slug can retain the chloroplasts from food and use this to create their own energy. This is process is similar to what a plant is doing and is called kleptoplasty. Some species of sea slug can live for months on the energy that they produce themselves.
The leaf sheep suck out the chloroplasts from the algae and then incorporate them into their own bodies. The leaf sheep is more or less solar-powered slugs.
Photo: Lynn Wu
Studying the leaf sheep can lead to the most wonderful ideas. From these ideas and suggestions it is possible to explore a topic from a range of different angles. For example, the process of photosynthesis or why leaf turn yellow and orange in the autumn. Often curriculum and schools materials teach things that were true a year ago, five years ago or even 50 years ago. There is a fear of using new knowledge and of confusing children. In this particular case, learning about the photosynthesis is hard enough.
Yet, I believe that it is cases like the leaf sheep that capture children’s attention and imagination. Also it may help them to remember the underlying principles of a process such as photosynthesis.
Basically, photosynthesis is the conversion of light energy into chemical energy in cells that contain chlorophyll, a green pigment. This process occurs in most plants and algae and in some bacteria and protozoans. And in some animals, like sea slugs. It is one of the most important processes on the planet. It provides humans with breathable air and it is the foundation for the entire food chain. For photosynthesis to occur, water, carbon dioxide, chlorophyll, and light are necessary.
We came up with the idea of an Eternal Magic Leaf Sheep Snack Bar. All you need is a bit of sunshine and the bar refills itself. Also we figured out that we needed to water the bar well – just the occasional drop of water. Then we added some leaf to symbolize chloroplasts.