I don't think all of them are bad, but the ones that show up in our tanks are usually a problem. They either eat something we have, reproduce to plague like proportions etc.
Picture would be helpful.
Not all are killers however can be a nuisance when in numbers. Time to hire a full time security guard - Lunare or Melanurus wrasse. They eat All flatworms
Picture would be helpful.
Not all are killers however can be a nuisance when in numbers. Time to hire a full time security guard - Lunare or Melanurus wrasse. They eat All flatworms