Parkinson's Rainbowfish Identification Guide
Field marks for identifying Parkinson's Rainbowfish, a red-finned rainbowfish of southeastern Papua New Guinea streams.
Read the full Parkinson's Rainbowfish encyclopedia entry →
Key identification features
- Deep, laterally compressed body typical of rainbowfishes
- Iridescent blue-green back fading to silvery-yellow flanks
- Reddish-orange tint on the dorsal, anal, and caudal fins, especially in males
- Two dorsal fins, with the second dorsal and anal fins showing a pointed rear edge in mature males
- Faint rows of reddish spots or dashes along the midbody
- Silvery-white belly contrasting with the darker back
- Large eyes and a moderately steep forehead
- Reaches about 10-12 cm
Common look-alikes
- Lacustrine rainbowfish: shows a more solid, vivid blue body without the reddish flank spotting seen here.
- Sepik rainbowfish: typically deeper-bodied with a more olive-toned back and different fin coloration.
- Boeseman's rainbowfish: has a sharply two-toned blue-front, yellow-rear body pattern absent in this species.
Where you'll see one
Found in rivers and streams of the Milne Bay and Central provinces of southeastern Papua New Guinea, usually in clear, flowing forest streams with sandy or rocky beds and overhanging vegetation providing shade and cover.
Frequently asked questions
How do I separate Parkinson's rainbowfish from the lacustrine rainbowfish?
Parkinson's shows reddish flank spotting and orange-tinged fins, while lacustrine rainbowfish has a more uniform, solid blue body.
What confirms a rainbowfish as Parkinson's rather than another Papua New Guinea species?
Its combination of a blue-green back, silvery-yellow flanks with faint red dashes, and reddish fin edges is distinctive among the region's rainbowfishes.