Fish Identifier

Clown Knifefish Identification Guide

Spot a Clown Knifefish by its blade-shaped body, humped back, and row of large dark eye-spots along the tail.

Read the full Clown Knifefish encyclopedia entry →
Clown Knifefish Identification Guide

Key identification features

  • Strongly compressed, knife-shaped body that tapers to a point at the tail
  • Long ribbon-like anal fin fused with a reduced tail, forming one continuous fin edge from mid-body to the tail tip
  • Tiny, separate dorsal fin set well behind the head
  • Arched, humped dorsal profile just behind the head
  • Silvery-gray body marked with a row of four to ten large dark, ring-edged eye-spots along the lower rear body
  • Upturned mouth; adults commonly exceed 2-3 feet

Common look-alikes

  • Spotted (Indonesian) knifefish: has irregular dark blotches instead of clean, ringed eye-spots
  • Bronze/featherback knifefish: much smaller and slimmer overall, with no spots anywhere on the body
  • African featherfin knifefish: sports a long feathery dorsal fin running nearly the whole body length, unlike the clown knifefish's short stub of a dorsal fin

Where you'll see one

Clown knifefish are native to slow, vegetated rivers, canals, and flooded forest pools of the Mekong and Chao Phraya basins in Southeast Asia. They have also become an established invasive species in canals and waterways of southern Florida, where they now breed in warm, still, weedy water.

Frequently asked questions

How do I recognize a clown knifefish versus other knifefish species?

Look for the row of large, dark, ring-edged spots running along the lower rear third of the body — this ocelli pattern is the clown knifefish's clearest field mark.

What body shape hints tell me it's a knifefish at all?

A blade-flat compressed body with a long fin running underneath from mid-body to the tail, paired with only a tiny dorsal fin, is the signature knifefish silhouette.