The Rainbow Parrotfish

Scarus guacamaia, more commonly known as the rainbow parrotfish, is the largest herbivorous fish native to the Atlantic Ocean. Adult males of this species can get to 1.2 meters in length. These fish are named for one of their life phase colorations in which they have deep teal-green bodies with flashes of vibrant orange, pink, and blue as well as for their beak-like mouths which they use to scrape up algae and corals for food. Rainbow parrotfish utilize mangroves such as those at Koch Key as nursery grounds before they move on to live at coral reefs. As a class, we observed these parrotfish at many of the reef sites that we visited such as Looe Key, Cheeca Rocks, and Tennessee Light. Parrotfish are diurnal, meaning they are active only during the day. At night, the rainbow parrotfish is known to retreat into crevices and rocky ‘caves’ within the reefs to sleep. One of the coolest facts about these fish is that they secrete a special mucous ‘cocoon’ around their bodies when they settle in to sleep. There are a few hypotheses on why the parrotfish secrete this mucous with the most well-supported offering that it aids in masking their scent from predators while they’re sleeping as well as acting as a protective covering to prevent sand from clogging up their gills. Another fun fact about rainbow parrotfish is that males of the species are known to have harems of females and, when the male dies, the most dominant of the females (usually the largest) changes her gender and takes his place. 

http://www.arkive.org/rainbow-parrotfish/scarus-guacamaia/
http://www.fishchannel.com/fish-news/2011/02/18/parrotfish-extra-slime-coat.aspx

Photo credits: Corey Corrick 

Photo credits: Dr. Joshua Voss

Photo credits: Dr. Joshua Voss