The mangrove rivulus lives in streams that are prone to drying up, so air breathing is a
definite advantage. A recent study done in Belize and Florida has found that these fish
can find out-of-water refuge in an odd place: the inside of rotting logs. These logs
have long galleries inside them that were originally bored by terrestrial insects. The
rivulus, which normally are very aggressive towards one another, agree to a truce and
pack themselves tight inside those galleries. There they can remain, without food,
breathing moist air, for up to 66 days.15