There are many mysteries in the ocean, if for no other reason than it
is hard to make studies under water. One of the most interesting
examples of ocean mysteries is cleaner shrimp and cleaner fish. These
small animals called cleaners live in reef areas that eat parasites and
dead skin. Larger fish including sharks and rays come to the cleaners
to have parasites and dead skin removed from them. In recent years
observers have noted that the cleaner fish will be cleaning a shark
hanging vertically in the water over where the fish
operates, while ten or fifteen other sharks will be swimming in a
circle nearby. The fish being cleaned will assume unnatural positions
that allows the cleaning to be more efficient and complete. As soon as
the shark being cleaned swims away, another shark peels away from the
circle and swims up to the cleaner fish to be cleaned. The observers
have not observed any conflict among the sharks or rays, and there has
never been a case where any of these animals ate or in any way harmed
the smaller cleaner fish or cleaner shrimp. In cases like the grouper
this is remarkable, since shrimp and small fish make up their entire
There are many complications in the behavioral patterns that are taking place here. Normally sharks are very competitive, and for them to lie still while being cleaned is very difficult for the shark. Sharks are very primitive fish, and normally have to swim constantly to keep sufficient water flowing through their gills to get enough oxygen. If there are strong currents, this problem is lessened, but it seems that sharks will seek out the cleaner fish no matter where the fish is located even if it is very difficult for the shark.
How does such a relationship come about? Evolutionary theory would suggest that sharks that allow themselves to be cleaned survive more readily than those that do not. That simple explanation does not explain the original development of the behavior. Is this a learned behavior? What would have caused either the cleaners or the fish being cleaned to attempt it? Why would the cleaner fish expose itself to such a risk, and why do not other fish eaters and shrimp eaters wipe out the exposed cleaners? It seems there is a special value assigned to the cleaners by all the animals of the area, and all fish no matter what their normal aggressiveness and behavior seem to honor the cleaners.
We would suggest this is an example of a designed behavior. The cleaned fish and the cleaner fish seem to have a genetic program designed into their genome that allows this system to function. It benefits the whole reef and the entire ecology of the ocean, but its complexity and design seems to be beyond the reach of blind mechanistic chance. This is just one more example of seeing things in the natural world which helps us to know there is a God through the things He has made (Romans1:19). Reference: Natural History, March 2007, page 8.
Back to Contents
Does God Exist?, NovDec07.