I had them with a 4" bichir in growout as well. Didn't harm them. They are the ones that wiggle really fast in the water, but don't really go anywhere right?
They're not bloodworms. Bloodworms prefer a muddier environment. Tanks will not suit them well.
They are still harmless creatures to me. No parasitic worms will stay outside of the fish's body for a period of time especially with the lack of nourishment from their host.
