Fish Identifier

Bicolor Anthias Identification Guide

Spot the sharp purple-to-yellow color split that instantly identifies this small Indo-Pacific anthias.

Read the full Bicolor Anthias encyclopedia entry →
Bicolor Anthias Identification Guide

Key identification features

  • Sharply two-toned body: front two-thirds lavender to magenta-pink, rear third bright yellow to orange, with a clean vertical boundary between the colors
  • Males develop an elongated filament on the dorsal fin along with slightly more saturated coloring than females
  • Slender, elongated anthias body with a forked tail and a small upturned mouth for feeding on zooplankton
  • Small size, typically under 5 in (13 cm), usually outnumbered by females within a group
  • Color intensity can vary somewhat with depth and lighting, but the sharp division between the two body colors remains a constant

Common look-alikes

  • Squarespot anthias — males show a squarish purple patch on an orange body instead of a clean bicolor split
  • Redfin anthias — pink overall with a red-tipped tail, lacking a sharp two-color division

Where you'll see one

Bicolor anthias favors steep outer reef slopes and current-exposed drop-offs across the Indo-Pacific, typically in deeper water (about 10-40 m), forming loose feeding aggregations above the reef alongside other anthias species.

Frequently asked questions

How do I recognize bicolor anthias underwater?

Look for the crisp color break partway down the body, purple-pink toward the head and yellow toward the tail, unlike other anthias whose colors blend gradually.

How can I tell a male from a female bicolor anthias?

Males show an elongated filament on the dorsal fin and more intense coloring, while females have a shorter, rounded dorsal fin and softer, more uniform pink-yellow tones.