Killifishes (Fundulidae)
# characteristics results
1a Large mouth, red or brown spots forming horizontal lines Fundulus dispar (Starhead Topminnow)
1b Small to normal sized mouth go to 2
2a Thick/dark midlateral stripe present go to 3
2b Thin or nonexistent midlateral stripe go to 4
3a Numerous small dark specks on body (especially posterior) and the more posterior fins (anal, dorsal, and caudal) Fundulus olivaceus (Blackspotted Topminnow)
3b Faint or absent dark specks on body (especially posterior) and on caudal, anal, and dorsal fins. Fundulus notatus (Blackstripe Topminnow)
4a Scales outlined with melanophores, body laterally compressed, and mouth superior. Lucania parva (Rainwater Killifish)
4b Melanophores not present go to 5
5a Lower jaw protrudes farther than upper jaw. Fundulus grandis(Gulf Killifish)
5b Jaws are in line go to 6
6a Snout is long (visually about twice as long as the diameter of the eye, looks stretched) Fundulus similis (Longnose Killifish)
6b Short snout go to 7
7a Terminal mouth and body has dark vertical bars (makes overall body looked striped hence the species name zebrinus) Fundulus zebrinus (Plains Killifish)
7b Superior/sub terminal mouth and golden or red flecks present on body (especially posterior) and caudal fin. Note: redish specks are present only on larger breeding age males. *Fundulus chrysotus (Golden Topminnow)