Odd worm/centipede type creature in my tank

Question
Hi,
I am in the process of fishless cycling with three various sized tanks. I am using live plants, though my apologies because I only really know the name of the Amazon sword, but needless to say, each tank has a good variety of plants. I am using scattered rocks and smooth river rocks and have planted my plants in soil with a good layer of fine gravel on top of that and then larger stone to stop my goldfish from trying to eat the gravel.

A couple of hours ago I noticed a piece of plant near the bottom of the tank...very odd because this plant normally floats if uprooted from its pot. Upon further inspection, I saw that there was a bright light green worm-type creature inside the stem of the plant, sticking its head? out and it also had what looked like little legs, like a centipede. It could move quite swiftly up and down the glass, going in and out of the plant stem and moving the small chunk of plant with it. I removed the chunk of plant and creature and put it in a container with aquarium water in case it was actually something good. I did try and take a picture, but it really is difficult to see, most especially since its color really matches the green of the plant so well.

Any clue what this might be and what I should do about it?

Thank you,

Barb

Answer
Hi Barb
Here's a link, try clicking on the insect stages and the arthropods links at the bottom.  They're just drawings, but will give you a better idea of maybe what it is, then you could do a search for more information on it:

http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/pond/...

Hope that helps, and hope it's nothing bad :)

Christy