Serpae Tetra Identification Guide
Spot a Serpae Tetra by its deep red-orange body, black shoulder blotch, and jet-black-edged dorsal fin.
Read the full Serpae Tetra encyclopedia entry →
Key identification features
- Deep, laterally compressed, diamond-shaped body typical of many tetras
- Rich blood-red to orange-red overall coloration, deepest along the back
- Distinct black, comma-shaped blotch just behind the gill cover on the shoulder
- Tall dorsal fin edged in solid black, contrasting sharply with the red body
- Anal fin also trimmed with a thin black margin
- Small adult size, generally 1.5-1.75 inches (4-4.5 cm) long
Common look-alikes
- Bleeding Heart Tetra is larger and rounder-bodied with a red spot centered on the flank rather than a black shoulder blotch.
- Flame Tetra shows a similar red hue but lacks the black-edged dorsal fin and has a smaller, less pronounced shoulder mark.
- Red Phantom Tetra has a translucent body with a dark shoulder spot but a clear, unmarked dorsal fin, unlike the Serpae's black-tipped one.
Where you'll see one
Native to slow, blackwater and clearwater tributaries of the Amazon and Paraguay-Paraná river basins in South America, where it schools in densely vegetated, tannin-stained waters with soft, acidic conditions.
Frequently asked questions
How can I tell a Serpae Tetra from a Flame Tetra?
Check the dorsal fin: Serpae Tetras have a bold black edge on the dorsal fin, while Flame Tetras have a plain red-orange dorsal fin without that dark trim.
What single mark best confirms a Serpae Tetra?
The black, comma-shaped blotch on the shoulder paired with the black-tipped dorsal fin together are the most reliable combination for confirming this species.