I have been teaching myself some marine biology by reading stuff from textbooks, web pages and scientific papers. And now I am digging into Introduction to the Biology of Marine Life (James L. Sumich & John F. Morrissey, Jones & Bartlett Publishers, 8th edition, 2004).
One thing I just learnt that really interests me is the role of the cleaner fish and cleaning stations in community fish health. It seems that in a coral reef ecosystem, for example, there are some cleaner fishes whose job is to pick away parasites and dead tissues from bigger fishes. These small cleaner fish would even get inside the bigger guys' mouths or gills to do their jobs. Those bigger clients will visit these 'cleaning stations' from time to time to have their body 'cleaned'. It reminds me of manicure shops where people can visit regularly for nailcare services. Only that this is more than just for good looks. Some study showed that when all cleaner fishes were removed from a coral reef community, the location was quickly vacated of most fishes and those remaining had frayed fins and suffered increased parasite attack.
Some questions came up in my mind:
(1) Are cleaner fishes selective of the type of diseased tissues or parasites that they would eat?
(2) My first thought is this: these cleaner fishes may have a powerful digestive system that breaks down all diseased stuff they eat. That way, they are protected from the diseases or parasites they pick up.
(3) If not, these cleaner fishes must be immune to quite a wide range of parasites or diseases, I think. And this will make them a wonderful research topic. Who knows what we can find out from them that may eventually be used to help boost human immune system or used to treat immune system-related human illness?