How to Identify Bicolor Anthias

To identify Bicolor Anthias (Pseudanthias bicolor), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Males typically exhibit a striking bicolor pattern: the anterior half of the body is bright yellow to orange-yellow, transitioning sharply to a magenta or purplish-pink posterior half. The dorsal fin often has elongated rays, and the caudal fin is deeply forked with elongated filaments. Females and juveniles are generally more uniformly orange-yellow to pinkish-orange, lacking the distinct bicolor demarcation and elongated fin rays of the males. Some individuals may display a prominent red or purple stripe running from the eye to the pectoral fin base.

Scale type

ctenoid

Mouth position

superior

Distinctive features

Sharp bicolor demarcation in males (yellow anterior, magenta posterior), Elongated dorsal fin rays and caudal fin filaments in mature males, Deeply forked caudal fin, Small, ctenoid scales

Dorsal fin

X spines, 16-17 soft rays; third dorsal spine often elongated in males.

Tail fin

Deeply forked with elongated filaments in males.

Pectoral fin

16-18 rays, typically clear to yellowish.

Distinctive fins

Pelvic fins are relatively long, reaching beyond the anal fin origin in males.

Identification Tips

1. 1

   Coloration (Males)

   Look for the distinct yellow anterior and magenta/purplish-pink posterior body coloration. This sharp bicolor pattern is a key identifier for mature males.

2. 2

   Fin Elongation (Males)

   Observe the elongated third dorsal fin spine and the filamentous extensions on the deeply forked caudal fin of males.

3. 3

   Coloration (Females/Juveniles)

   Females and juveniles are more uniformly orange-yellow to pinkish-orange, lacking the sharp bicolor pattern. They also lack the elongated fin rays.

4. 4

   Habitat

   Typically found hovering in schools over outer reef slopes and drop-offs, feeding on zooplankton.

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