10 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
The markings on the fins of the males become at this period very bright and dis- 
tinct, and add more to its ornamental appearance than the brightest coloration does to 
other species. The colors assumed at this period are a mingling of delicate and inde- 
finable shades of blue and green with bronze and iridescent reflections, which, with the 
striking effect produced by the markings, make it perhaps as beautiful as any of the 
family, if not so gorgeously colored. 
The “rainbow darter,” also called blue darter, soldier fish, etc., is probably not 
found east of the Allegheny Mountains. It is one of the most highly colored species 
of the family Percidce. The prominent colors are red, yellow, orange, blue, and green, 
arranged in conspicuous patches, or regular patterns of the most striking character. 
The specimens in the aquaria are from the vicinity of Cincinnati, Ohio, and Neosho, 
Missouri, and correspond perfectly in color and markings. 
The following probably inadequate description of the markings may give some 
idea of the gorgeous colors of the fish: Lower half of spinous dorsal deep brick-red 
with a line of lemon-color arranged in a series of arches on the membrane just above 
the back; a lemon-color line, composed of a series of arches also, at the upper margin 
of the dark brick-red, arranged in reverse order to the lower lemon line, that is, with 
the concavity of the arches turned upward; the upper half of the fin of a very deep 
indigo-blue. Soft dorsal, an artistically arranged pattern of green, blue, yellow, and 
light brick-red, difficult to describe except by diagram. Ventral and anal fins with 
broad band of pale- blue (becoming more intense at times of greatest excitement) at base 
and tips, with a broad central band of deepest indigo-blue; pectoral fins transparent, 
yellow at base; caudal transparent, bordered with dusky and pale blue; a blue blotch 
across the nape; breast with small orange spot; a lemon-yellow dash around the throat. 
This species is more addicted to perching on aquatic plants near the top of the 
water; this habit, with its darting movements (which are analogous to the flight of 
birds), not having a swimming bladder, make it very bird-like in appearance. 
At the spawning period a spot would at times be selected, apparently, among the 
plants as a place of deposit for the eggs, and, although in their active sexual demon- 
strations they would travel to every part of the tank, they would invariably return 
and perch in the same place. As with the tessellated darter, there was undoubtedly a 
mating, although usually two or three other males would hover very near and 
frequently make rushes to join the female, in which they were invariably defeated and 
driven away by the chosen male. At times the spawning would take place among 
the pebbles on the bottom of the tank, the female dragging herself along in a quiv- 
ering manner, the male pressing closely alongside, and other males following closely 
in the rear, evidently bent on assisting in the fertilization of the eggs. All the fish 
not actually engaged in the spawning were evidently in a state of great excitement, 
and followed after, eating the eggs as fast as they were deposited. As the tessellated 
darters are much the larger, the eggs could hardly have been protected from them, 
although many smaller fish, notably the 4-spined stickleback, under like circumstances, 
would attack anything regardless of size. 
It is probable that in a wholly natural condition the eggs are deposited on the 
under or protected sides of stones where they would be more easily guarded. In the 
limited space of an ordinary aquarium tank, well stocked for exhibition, there would 
hardly be a sufficiency of desirable spawning-places for all. In some cases the females 
would remove the sand from beneath a part of small stones by means of the fins and 
