Do Fish Sleep?

I was watching the fish in my fish pond at home .. A question that's always kept me wondering is whether fish sleep or not. My mother told me once that she saw the goldfish in our pond almost leaning on the small pebbles we've put in it. I almost didn't believe her until today when i finally managed to give up laziness(:P) and do a search on the web for an answer.

I learnt that fish do sleep, but not quite like we humans do.. It's more like, they go into a "resting phase" with reduced activity of brain and body.. except sharks which have to keep moving to push water through their mouths in order to breathe..

Now let's not give my fingers all that exercise with so much typing(:P), Here's a few links you could check for the answer:

1. Big Question: Wordpress
2. Ask a scientist

3. Discoverymagazine
4. Lifeslittlemysteries