Tuesday, November 16, 2004

Today's science word is ...

Annelid.

This evening I have been packing up my pet worms to take to school. 'What?' You ask, 'You have pet worms?'

Well, so I exaggerate a little. They're not pets, but I do keep a bin full of earthworms in my kitchen. They are a kind of earthworm called the 'red worm' (Eisenia foetida), and the reason I have them hanging about the house is to compost my garbage into the best plant food on the planet.

Earthworms are segmented worms, belonging to the Phylum Annelida. They are commonly referred to as Annelids.

Did you know that earthworms have a primitive brain and nerve cord, several hearts and a complete circulatory system? That they are hermaphrodites, having both male and female sex organs on the same individual worm? Well, it was news to me too, before I took a closer look several years back.

Earthworms perform a valuable service aerating the soil and decomposing plant matter back into available nutrients. It's interesting, however, that nearly all the earthworms of North America are not native to the continent; they were brought over from Europe. This suggests that the ecological landscape 500 years ago was quite a bit different than it is today.

A few cool sites about Annelids can be found here, and here. Enjoy!

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