Royal Gramma Identification Guide

Key identification features

• Small, slender body rarely exceeding 3 inches (8 cm)
• Bold two-tone coloration: deep violet-purple on the front half, bright yellow-orange on the rear half
• Sharp, clean demarcation line between the two colors, running diagonally behind the head
• A distinct black spot on the front of the dorsal fin
• Thin dark line running through the eye
• Often seen swimming upside down under ledges
• No scales are visible under normal light, giving the skin a smooth, glossy look

Common look-alikes

• Bicolor Dottyback: similar purple/yellow split but lacks the dorsal fin black spot and has a more evenly rounded color break rather than a diagonal one
• Royal Dottyback: nearly identical color scheme, but the color transition is more blended and it lacks the sharp diagonal edge seen in the Royal Gramma
• Orchid Dottyback: shows an overall purple wash without a defined yellow rear half, so the two-color split is missing entirely

Where you'll see one

Royal Grammas inhabit reef drop-offs, caves, and ledges throughout the Caribbean Sea, typically at depths of 20-200 feet, where they hover near shelter and dart back inside caves when approached. Small groups often share the same overhang, staying oriented with their bellies toward the ceiling.