Charles Q. Choi
Source: MSNBC
November 16, 2010

Just as some people must sleep with mosquito nets to ward off the bloodsuckers, coral reef fish apparently spin cocoons of mucus before slumbering to keep away biting parasites, scientists find.

Coral reef fishes such as parrotfishes and wrasses sleep soundly in mucus cocoons that have long fascinated recreational scuba divers and are often a main attraction on night dives. Surprisingly, until now, no experimental studies had examined their function.

Past observational studies have suggested these gooey blankets, which are secreted from the fishes' mouths, somewhat protect fish from nocturnal predators such as moray eels. However, researchers also found many cocooned fish were still eaten.

To read the full text of the article, click here.