Bicolor Parrotfish, Scarus rubroviolaceus

Bicolor Parrotfish, Scarus rubroviolaceus, Juvenile. Underwater photograph taken in Zihuantanejo Bay, Guerrero, in January 2023. Photograph courtesy of Ron Woheau, Zihuantanejo.

Bicolor Parrotfish, Scarus rubroviolaceus, Initial Phase (IP), Female. Fish caught from coastal waters off Green Island, Taiwan, October 2018. Length: 13 cm (5.1 inches).  Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).

Bicolor Parrotfish, Scarus rubroviolaceus, Initial Phase (IP), Female. Underwater photographs taken in coastal waters of Los Cabos, Baja California Sur, May 2018. Photographs courtesy of Bob Hillis, Ivins, Utah.

Bicolor Parrotfish, Scarus rubroviolaceus, Terminal Phase (TP), Male. Underwater photograph taken in coastal waters off Kailua-Kona, Hawaii, November 2015. Photograph courtesy of Bob Hillis, Ivins, Utah.

Bicolor Parrotfish, Scarus rubroviolaceus, Terminal Phase (TP),  Male. Underwater photograph taken in coastal waters of Los Cabos, Baja California Sur, May 2018. Photograph courtesy of Bob Hillis, Ivins, Utah.

The Bicolor Parrotfish, Scarus rubroviolaceus, is a member of the Parrotfish or Scaridae Family, that is also known as the Ember Parrotfish and the Redlip Parrotfish and in Mexico as loro bicolor. Globally, there are sixty-four species in the genus Scarus, of which ten are found in Mexican waters, six in the Atlantic and four in the Pacific Ocean.

The Bicolor Parrotfish has an elongated, oval, and compressed body. Juveniles have whitish bodies with clear fins. They have three broken brown lines across their flanks, the lower one being the widest and having pale dots along its length. As they mature, their body becomes white and they have three brown to olive color stripes with white spots, a large white blotch at their caudal fin base, and a dark bar extending down from the front of their dorsal fin. Initial Phase (IP) females are gray anteriorly and transition to light tan posteriorly with small black spots and dark lines on their side; they have red fins. Terminal Phase (TP) males are green to blue-green; many have a purple anterior half which gives rise to their common name; they have a pair of blue bands on their chin, pink lines above and below their mouth, and a blue-green beak; they have a steep, blunt, and square head with large males developing a strong hump on top. They have 1 or 2 canine teeth on the rear side of their top jaw. Their anal fin has 3 spines and 9 rays; their caudal fin is slightly concave in juveniles and very concave in mature adults; and, their dorsal fin has 9 spines and 10 rays and is continuous. They are covered with large smooth scales. Their lateral line has two sections.

The Bicolor Parrotfish is a shallow water benthopelagic coastal species found in and around rocky and coral reefs in tropical and subtropical waters at depths up to 37 m (120 feet). They are fast-growing and reach a maximum of 70 cm (2 feet 4 inches) in length. They are found as solitary individuals, in pairs or in large dense schools. They are daytime foragers spending 80% of their time in search of food, primarily scraping algae and small organisms off rocks. At night they retire within the reef and construct a cocoon in which they sleep. They are protogynous hermaphrodites with mature females changing to males around age thirteen. Reproduction is oviparous with spawning occurring in large aggregations. The eggs are fertilized externally and are pelagic but settle to the bottom and hatch fairly quickly. They have lifespans of up to twenty years. The Bicolor Parrofish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Bicolor Parrotfish is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found only in the southern half of the Sea of Cortez and along the coast of the mainland south to Guatemala.

The Bicolor Parrotfish is similar to, and can be confused with, the various phase colors of the Azure Parrotfish, Scarus compressus, the Bluechin Parrotfish, Scarus ghobban, the Bumphead Parrotfish, Scarus perrico, the Loosetooth Parrotfish, Nicholsina denticulata, and the Stareye Parrotfish, Calotomus carolinus, however, these fish all have more pointed snouts and lack the pink lines found above and below the mouth of the Bicolor Parrotfish.

From a conservation perspective the Bicolor Parrotfish is currently considered to be of Least Concern, with stable, widely distributed populations but will most likely be reclassified as NEAR THREATENED within the next  ten years. Loss of habitat (coral reefs and mangroves) and overfishing combined with declines in numbers and sizes make their long-term survival of concern. They are an important food fish in many parts of their range. They are also used by the aquarium trade at a nominal level.