1a |
Dorsal fin origin more anterior than anal fin origin |
go to 2 |
1b |
Anal fin or gonopodium more anterior than dorsal fin |
go to 3 |
2a |
Horizantal stripes of dark pigmentation, Mouth superior and pointed |
Poecilia latipinna (Sailfin Molly) |
2b |
Female only species, small dorsal fin, and depressed head |
Poecilia formosa (Amazon Molly) |
3a |
Arched back, deep bodied, and rounded snout |
Gambusia nobilis (Pecos Gambusia) |
3b |
elongated body |
go to 4 |
4a |
Head rounded, melanophores on scales form crescent shapes, 8 dorsal fin rays~ This species is endangered |
Gambusia gaigei (Big Bend Gambusia) |
4b |
Head depressed and/or no cresent markings |
go to 5 |
5a |
Snout rounded with melanophores clustered on lower jaw~ dark midventral stripe present with overall yellow body |
Gambusia geiseri (Largespring Gambusia) |
5b |
Snout pointed, suborbital bar may be present, brood patch found in pregnant females |
Gambusia affinis (Western Mosquitofish) |