Squarespot Anthias Identification Guide

Key identification features

• Males: deep orange-red body with a large, sharply squared magenta-purple patch centered on the flank, bordered by faint violet streaking toward the head
• Females: pinkish-orange body with a pale yellow stripe running along the back, no square marking, and a more uniform, plainer overall tone
• Slender, elongated anthias body with a forked to lunate tail and a small, upturned mouth suited to picking plankton from the water column
• Small size, rarely exceeding 7 in (18 cm), with males noticeably larger and more colorful than females in the same group

Common look-alikes

• Bartlett's anthias (Pseudanthias bartlettorum) — smaller pink-and-yellow fish that never develops the male's square purple patch and has a plainer tail
• Threadfin anthias (Pseudanthias huchtii) — males show a purple wash and a long trailing dorsal filament but lack a defined squared blotch on the flank

Where you'll see one

Squarespot anthias favor outer reef slopes and current-swept drop-offs across the Indo-Pacific, usually in deeper water (about 15-40 m), where they form loose to large aggregations near walls and ledges, feeding on drifting zooplankton just above the reef.