Can you guys give me some advice on what these little worm things are? These pics are from my 15 column with cherry shrimp and oto catfish, I had guppy fish in there but moved the last one out about 10 days ago. I noticed these little worms in the substrate and on the almond leaves I have in the tank. Are these some kind of parasite? Do I need to get rid of them? If so, how?