Yellowfin Rainbowfish Identification Guide
Field marks for spotting the yellow-finned Yellowfin Rainbowfish of northern Australia and separating it from similar rainbowfish.
Read the full Yellowfin Rainbowfish encyclopedia entry →Key identification features
- Slender, moderately deep body, laterally compressed
- Olive to bluish-grey back with silvery flanks and a faint horizontal stripe formed by dark scale edges
- Bright yellow tinge across the dorsal, anal, and caudal fins, more intense in males
- Two dorsal fins, the second longer-based than the first
- Small dark blotch or bar sometimes visible just behind the gill cover
- Rounded snout and moderately large eyes
- Grows to about 6-9 cm
Common look-alikes
- Black-banded rainbowfish: shows a bolder, more continuous dark midlateral band rather than the faint stripe seen here.
- Western rainbowfish: fins washed with blue or red tones rather than the strong yellow of this species.
- Threadfin rainbowfish: males grow elongated, trailing dorsal and anal fin rays that yellowfin rainbowfish lack.
Where you'll see one
Found in rivers, billabongs, and floodplain waterholes across northern Australia, including the Top End of the Northern Territory and the Kimberley region of Western Australia, typically in still or slow-flowing, well-vegetated water, often in loose schools near submerged timber or reed beds.
Frequently asked questions
What's the easiest way to spot a yellowfin rainbowfish?
Look for the yellow wash across the dorsal, anal, and tail fins combined with only a faint, not bold, dark stripe along the flank.
How do I separate it from a threadfin rainbowfish?
Threadfin rainbowfish males have long, trailing filaments on the dorsal and anal fins; yellowfin rainbowfish fins stay short and rounded.