Fish and birds live in very different worlds, to say the least. So how can the average seabird, who feeds on many ocean residents, form a partnership with a fish? As it turns out, there exists an unusual symbiotic relationship between sunfish and seabirds. The sunfish itself is an unusual specimen to begin with. These large, tailless fish are not going to win any deep-sea beauty contests, but they have caught the attention of one flighty oceangoer: the albatross.
In the waters of the North Pacific, a Japanese research vessel spotted a most unusual pairing. A large school of mola mola sunfish was observed floating at the surface, a number of albatrosses in the water close at hand. Upon closer inspection, the team observed that these fish were carrying parasites called Penella, a copeod crustacean. The Penella buries its head into the flesh of its victim, leaving a long egg string hanging out.
As the scientists watched, the fish would follow the birds, and the albatross would extract the parasite and eat it! Other birds caught on and a full fledged sunfish cleaning ensued. The sunfish were seen trying to attract the birds, swimming alongside them and exposing their sides to their winged helpers.
Of course, this is not the only example of cross-species symbiotic relationships. On land, aptly named “tick birds” are often observed riding along on mammals like cows and water buffalo, cleaning parasitic insects from the host’s fur. Under the water’s surface, small fish like the cleaner wrasse or cleaner shrimp are doing swift business with the daily parasite removal from their reefmates. Sharks have their own special maid service in the form of the remora, which picks off parasites as well as clearing up any leftovers the shark may inadvertently drop.
But how did the sunfish figure out that the albatross could be the perfect cleaning service? Is this an exclusive relationship or will other birds help out? Science hasn’t answered these questions yet but clearly the sunfish-albatross bond is definitely one of the more unusual in the animal, and fish, kingdom.
