As a kid, would you hide under your blanket to avoid monsters lurking in your closet? Well, many Chlorurus genera of parrotfish, such as the Bullethead Parrotfish (Chlorurus spilurus), not only hide from predators, but make the blanket that they hide under! They will find a nook in the coral reef in the evening and secrete mucous around themselves, that can be up to 3 inches (7.6cm) thick in some places. This mucous “sleeping bag” is hypothesized to protect the parrotfish from eels, who hunt by smell at night. It is also hypothesized that the mucous covering may deter small parasites, acting as a “mosquito net”.

Sketch and fact contributed by Karli Chudeau

Sources:

Hoover, J.P. (2008). The Ultimate Guide to Hawaiian Reef Fishes: Sea Turtles, Dolphins, Whales, and Seals. Honolulu, HI: Mutual Publishing.

Grutter, A.S., Rumney, J.G., Sinclair-Taylor, T., Waldie, P., & Franklin, C.E. (2010). Fish mucous cocoons: the ‘mosquito nets’ of the sea. The Royal Society Journal, 7(2), 292-294, DOI: 10.1098/rsbl.2010.0916.