The Blue Streak AKA Cleaner Wrasse gets all of it's nutritional needs from the parasites and ich it cleans off of other fish. That's why they usually starve to death even though they eat fish food. Thats why my friends and I share two cleaner wrasses. They are a mated pair. We have shared them for about two years now. Shared means we rotate them to different tanks so they always have something to clean.