How to Identify Bicolor Parrotfish

To identify Bicolor Parrotfish (Cetoscarus bicolor), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Highly variable with age and sex. Juveniles are predominantly white with a prominent orange-red saddle on the back and a black spot on the dorsal fin. Initial Phase (IP) adults (typically females, but also some males) are mottled brown to reddish-brown with lighter undersides. Terminal Phase (TP) males are vibrant, with a green body, pinkish-orange margins on the scales, a blue-green head with pinkish-orange markings around the mouth and eyes, and often a prominent hump on the forehead. The caudal fin is typically blue-green with pinkish-orange margins.

Scale type

cycloid

Mouth position

terminal

Distinctive features

Strong, fused beak-like teeth for scraping algae from coral and rock surfaces., Pronounced sexual dichromatism and ontogenetic color changes., Terminal phase males often develop a nuchal hump., Large, robust body., Large scales.

Dorsal fin

9 spines, 10 soft rays; continuous.

Tail fin

Truncate to slightly emarginate in juveniles and IP, becoming more rounded or slightly emarginate in TP males.

Pectoral fin

14-15 rays; relatively large.

Distinctive fins

Pelvic fins are thoracic, with 1 spine and 5 soft rays. Anal fin has 3 spines and 9 soft rays.

Identification Tips

1. 1

   Juvenile coloration

   Look for the distinctive white body with a large orange-red saddle on the back and a black spot on the dorsal fin. This is a key identifier for young individuals.

2. 2

   Initial Phase (IP) coloration

   Observe for mottled brown to reddish-brown bodies, often with lighter ventral surfaces. These are typically females or non-dominant males.

3. 3

   Terminal Phase (TP) coloration

   Identify the vibrant green body with pinkish-orange scale margins, a blue-green head with pinkish-orange facial markings, and a potential nuchal hump. This indicates a dominant male.

4. 4

   Body shape and size

   Note the robust, elongated body and the large size (up to 90 cm total length) compared to many other parrotfish species.

5. 5

   Beak-like mouth

   All parrotfish possess fused teeth forming a beak, but Cetoscarus bicolor's is particularly prominent for its size, used for scraping algae.

Explore Bicolor Parrotfish