I have had a 4"Crocea and a 10" Deresa in my tank now for probably 3 years, I know I have plenty of bristle worms. I got rid of one that was 18" long when I was scrubbing rock this winter. I have also had a few different types of wrasses, including a six line and nothing has ever bothered them. Unfortunatly I have a beautiful big Powder blue tang that rules my tank and adding new fish is very difficult, somehow he learned the trick of chasing fish to the top of the tank and flipping them out with his tale. Once the clams get acclimated and find a spot they like they are actually pretty hardy.