The Banded Coral Shrimp (Stenopus hispidus), also known as the Banded Cleaner Shrimp, is a well-known inhabitant of tropical coral reefs. It is found in the Western Atlantic from Brazil all the way up to Canada, throughout the entire Caribbean region and even around Australia and New Zealand. Often initially spotted by its long, bright-white antennae sticking out of crevices, where it likes to hang upside down, its appearance quickly changes to a stiking colouration with alternating bands of dark-red and white. The deepest it has ever been found, is at the depth of 210 metres, but since the fish that it cleans to gather its food are most abundant in the shallow reefs, it is commonly found just below the low tide line, in waters between two to four metres deep.
Whereas the carapace (body) can grow up to 6 centimetres, the length of the antennae can be triple that size. Being a cleaner shrimp, it is with these exceptionally long antennae that it signals to passing fish to let them know that they can get themselves cleaned. It whips its antannae, while it performs a little ‘dance’ swaying its body from side to side. This attracts fish that, in turn, start flashing their colours to signal to the shrimp that they need cleaning. The fish moves in close enough for the shrimp to reach or, when the fish is big enough, it simply just ‘jumps’ on using their swimmerets, after which it starts removing parasites, fungi and damaged tissue using its three pairs of claws.
The adult Banded Coral Shrimp does not seem to have any natural predators. The symbiosis between the shrimp and the reef community is highly developed to a point where the shrimp can safely enter the mouth and gills of a fish without being eaten. In an experimental set up, a Banded Coral Shrimp was even placed in a tank with an octopus, which are known to eat crustaceans at a regular basis. Even though the octopus was not being fed during the experiment, the shrimp was not eaten for several weeks, until the moment the octopus apparently got too hungy.
Two things you might not know about this little creature is that first of all, it is very faithful. A trait mostly associated with mammals and some birds, this little crustacean also choses its mate to pair for a lifetime. The other thing is that they’re very territorial and being as small as they are, this means that their territories can’t be that big. So when you plan your holidays on the same tropical island two years in a row, you will have a big chance of finding the exact same Banded Coral Shrimp (or its mate) within a metre from where you saw it last year.