Fig. 245.—Black-sided Darter, Hadropterus aspro (Cope & Jordan). Chickamauga River.
The genus Hadropterus includes many handsome species, most of them with a black lateral band widened at intervals. The black-sided darter, Hadropterus aspro, is the best-known species and one of the most elegant of all fishes, abounding in the clear gravelly streams of the Ohio basin and northwestward.
Hadropterus evides of the Ohio region is still more brilliant, with alternate bands of dark blue-green and orange-red, most exquisite in their arrangement. In the South, Hadropterus nigrofasciatus, the crawl-a-bottom of the Georgia rivers, is a heavily built darter, which Vaillant has considered the ancestral species of the group. Still more swift in movement and bright in color are the species of Hypohomus, which flash their showy hues in the sparkling brooks of the Ozark and the Great Smoky Mountains. Hypohomus aurantiacus is the best-known species.
Fig. 246.—Green-sided Darter, Diplesion blennioides Rafinesque. Clinch River. Family Percidæ.
Diplesion blennioides, the green-sided darter, is the type of numerous species with short heads, large fins, and coloration of speckled green and golden. It abounds in the streams of the Ohio Valley.
Fig. 247.—Tessellated Darter, Boleosoma olmstedi (Storer). Potomac River.
The tessellated darters, Boleosoma, are the most plainly colored of the group and among the smallest; yet in the delicacy, wariness, and quaintness of motion they are among the most interesting, especially in the aquarium. Boleosoma nigrum, the Johnny darter in the West, and Boleosoma olmstedi in the East are among the commonest species, found half hidden in the weeds of small brooks, and showing no bright colors, although the male in the spring has the head, and often the whole body, jet black.
