Green Swordtail Identification Guide
Identify the green swordtail by its olive-green body, reddish lateral stripe, and the male's black-edged sword.
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Key identification features
- Elongated, streamlined body with an olive-green base color
- A reddish-brown to brownish horizontal stripe runs from behind the gills to the base of the tail
- Males grow a long, saber-like extension from the lower caudal fin rays, typically yellow-orange with a black lower margin
- Dorsal fin is modest and unremarkable in size
- Females lack the sword and appear deeper-bodied and rounder
- Adults reach about 4-6 inches including the sword in males
Common look-alikes
- Red swordtail (color strain): same body shape and sword but with an overall red rather than green base color.
- Platy: lacks any sword extension and has a shorter, deeper body.
- Female green swordtails vs. female platies: both are plain, but swordtail females are more elongated and slightly larger with a hint of the lateral stripe.
Where you'll see one
This is the classic wild-type coloring of the swordtail species, found in fast-flowing streams and rivers across Mexico and northern Central America, from Veracruz south to Honduras, in clear, well-oxygenated water.
Frequently asked questions
How is a green swordtail different from other swordtail color strains?
It shows the natural wild-type coloring: an olive-green body crossed by a reddish-brown lateral stripe, whereas selectively bred strains show solid red, black, or other colors instead.
What confirms a male green swordtail versus a female?
Only males grow the long sword-like extension on the lower tail fin edged in black; females are rounder-bodied, lack the sword entirely, and are otherwise plainer.