•Why the Odd Name?"Stoplight Parrotfish" might sound like a funny name, but it fits this fish perfectly. Divers will notice immediately that it has a strong beak resembling a parrot's. Just like traffic signals, Stoplight Parrotfish undergo a color change during their lifecycles: they change from red to green.
•Identification: How Divers Can Spot a Stoplight Parrotfish
Male and female Stoplight Parrotfish look very different. Both males and females have obvious beaks, but the similarities end there.
Adult females display large, black and white scales and a bright red belly and fins. Their faces have an almost marbled appearance, with a swirling pattern of black and white, and a black beak. Females are 5 to 10 inches long on average.
Adult males are bright green, with a yellow crescent on the tip of their tails, and a row of brilliant yellow scales at the tail base. A bright yellow spot marks their heads above the gills. Males are much larger than females, and measure 13 to 17 inches.
Juvenile, or young, Stoplight Parrotfish, have dark reddish-brown bodies, lighter, yellowish heads, and are marked with three rows of white spots on the body, as well as a white bar at the base of the tail. They are 2-5 inches long.
•Habitat: Where Can Divers Encounter the Stoplight Parrotfish?
Stoplight Parrotfish thrive throughout the Caribbean and Western Atlantic, South Florida, the Gulf of Mexico, the Bahamas, and Bermuda. Divers encounter these versatile fish at depths ranging from 3- 50 meters. Young fish hide camouflaged in sea grass beds, while adults hover in plain view over the coral reef.
A good way to locate Stoplight Parrotfish when diving is to look for bite marks on the coral. These will be white exposed patches in the otherwise colorful reef that are normally about a quarter in size. Male Stoplight Parrotfish bite chunks out of healthy coral to mark their territory. When you see bite marks, expect to see one green male and numerous red females (his harem) in the area.
•Why Are Stoplight Parrotfish Interesting to Watch on a Dive?
Stoplight Parrotfish appear unconcerned about divers’ presence, and only move away when very closely approached. Many times, if they are chowing down on a tasty piece of coral, they don’t even notice divers. This allows divers to watch them closely for some interesting behaviors.
They Snack on Coral: Stoplight Parrotfish use their beaks to break of pieces of both dead and living coral, which they grind up in their mouths to release the algae living inside. Divers can be entertained for an entire dive watching these parrotfish take greedy bites from the reef. They are noisy eaters, and if divers pay attention, they can hear loud crunches and scraping noises as the parrotfish eat. Learn to recognize this sound, and it can alert you to unseen parrotfish in the area.
They Poop Sand: Stoplight Parrotfish digest rocky coral and release the ground-up limestone as sand. Divers frequently see parrotfish releasing long lines of digested sand, which drift and hang like curtains in the water before settling gently to the ocean floor. Stoplight Parrotfish are some of the greatest fish producers of sand on the reef, and it is very likely that divers will see this behavior wherever Stoplight Parrotfish are present. Large parrotfish can produce up to 1 ton of sand a year.
Deloach, Ned and Humann, Paul, Reef Fish Behavior. Pages 280-285, and 293-296, New World Publications, 1999.
Deloach, Ned and Humann, Paul, Reef Fish Identification. Pages 198-199, New World Publications, 1989.
Leonard, Jared, "Stoplight Parrotfish" http://jrscience.wcp.muohio.edu/fieldcourses03/PapersMarineEcologyArticles/StoplightParrotfish.html 2003
Smith,Tim, "The Bahamas: A Closer Look at the Colorful and Unique Parrotfish." http://jrscience.wcp.muohio.edu/fieldcourses02/PapersMarineEcologyArticles/TheBahamas.ACloserLookatt.html, 2002