The Cleaner Wrasse is famous for its 'cleaning stations' on the reef, where it removes parasites and dead tissue from other, often much larger, fish. It has a distinctive blue body with a black stripe that widens towards the tail. While its behavior is fascinating, this fish has a dismal survival rate in captivity. It is an obligate parasite feeder, and prepared foods are almost never a sufficient long-term substitute. Most experts strongly discourage their purchase. An interesting fact is that 'client' fish recognize cleaner wrasses and will queue up for their services, even predators will not harm them during the cleaning.