18a. (From 17a.) Lateral stripe terminating in distinct, basicaudal spot; posterior portion of dorsal fin with black blotch (best seen in adults); body coloration silver to blue-green and without numerous black or brown speckles; pharyngeal teeth 0, 4-4, 0.
spotfin chub
Cyprinella monacha

18b. (From 17a.) Lateral stripe (if present and continuous) not terminating in basicaudal spot; posterior portion of dorsal fin without black blotch; body coloration with numerous black or brown speckles; pharyngeal teeth 2, 4-4, 2.
blacknose dace
Rhinichthys atratulus