Emerald Rainbowfish Identification Guide

Key identification features

• Deep-bodied and laterally compressed, with a humped nape in mature males
• Bright emerald-green to yellow-green iridescent body in males
• Females and young are paler silvery-green and less vivid
• Two dorsal fins, with a faint yellow or greenish wash on the fins
• Steep, rounded forehead profile
• Large, dark eyes set high on the head
• Rounded caudal fin with a faint darker trailing edge
• Reaches about 8-10 cm

Common look-alikes

• Salmon-red rainbowfish: shares the same humped-back body shape but is salmon-red rather than green.
• Dwarf neon rainbowfish: much smaller and slimmer, with electric-blue rather than solid green coloration, and typically found in different, smaller drainages.
• Threadfin rainbowfish: males show elongated trailing fin rays that emerald rainbowfish lack.

Where you'll see one

Found in lakes and slow tributary streams of Papua and Papua New Guinea, typically in open water over vegetation near lake shorelines, often forming loose aggregations away from dense cover and close to drop-offs into deeper water.