I just found this mysterious dude in my tank. He seems to only be eating detrius so I'm guessing/hoping it's harmless. I did my best to get clear pics but it was difficult. This guy is round with a small black head and about 1/8" thick give or take. He also has a black stripe part of the way down his body .I have bristle worms so I know what they are but this dude is a mystery .