Some divers who are familiar with the antics of
cleaner shrimp, which eat parasites and dead skin off
fish, do this party trick underwater -- remove their
regulators and encourage these industrious little critters
into their own mouths to clean their teeth. Why
do shrimp do this for us, and should we let them?
Benjamin Titus, a biologist at the American
Museum of Natural History, told National Geographic,
"Shrimp have very poor vision, which might explain
why they don't shy away from human clients." They
may just see a diver as a very large client fish.
However, Eleanor Caves, a researcher at Duke
University, suggests that by occupying a shrimp's
cleaning station, a diver may be scaring off or physically
blocking clients that need cleaning. "It's great
when people gain a broader understanding of what's
actually on a reef, but the best practice for divers,
and anyone out enjoying nature, is to leave the animals
alone."
From a diver's perspective, the only hazard is
that you need to hold your breath while letting the
little critter get to work on your teeth. This could
be dangerous if you inadvertently start ascending
because, as Titus reminds us, "the first rule of diving
is 'don't hold your breath,' which can increase your
risk of a lung expansion injury."