I've heard the same as Chris. It sounds to me as if H. melanurus is the best among wrasses for pest control; it doesn't hurt that it is also a gorgeous fish and is fairly well suited for captivity. Unfortunately, you'll find that they are hard to find in Canada although American suppliers occasionally get them. That said I just found one at J&L last week, completely by chance (juvenile coloration so they didn't even know what it was)
