Parasite Or Food?

[jlOisAhoTti]

Alright, I took a picture of what I thought was a blackworm but I took it into the local pet store today and my knowledgeable friend that worked there couldn't tell. In the picture I took I have a blackworm and my worm that I found colonizing in my 10 gallon guppy tank. Is it a parasite or is it a blackworm?

 

[Amunet]

Well I have no idea, but they certainly do look similar.. cept for the color obviously.