Storm_Rider: Well, they are worms from my tank and they look like Tubifex and act like Tubifex, so I would say that they are Tubifex worms.
Here's more pictures: tubifex - Google Image Search
California blackworms (Lumbriculus variegatus)
do look a bit like Tubifex (Tubifex tubifex
), but they are totally different species. They both belong to class Oligochaeta, but tubifex worms belong to order Clitellata and family Tubificidae, blackworms belong to order Lumbriculida and family Lumbriculidae.
Wasserpest: Thank you for making this sticky. I am really happy with this 350D, it fits my tiny hands perfectly.
spypet: Thank you for your contribution, the pictures are great. I'll be adding some information and the pictures to the first post as soon as I have time, so we will have everything in the first post and in some sort of order.