376 
BULLETIN OF THE BUREAU OF FISHERIES 
9. 6 -millimeter stage. — Dorsal VI, 10 (broken and incomplete); anal I, 7. Total 
length, 9.6; standard length, 8.1; length to vent, 5.1; greatest depth, 1.54; diameter of 
eye, 0.9 millimeter. Myomeres, 15 to vent plus 22 behind. Changed from preceding 
principally in partial development of spines and rays ; further development of ventrals 
and pectorals, completion of caudal, and the addition of a few scattered chroma to- 
phores over head, dorsal aspect of body, and lateral line. 
15.0- millimeter stage. — Dorsal VIII, 11; anal I, 8. Total length, 15.0; standard 
length, 12.6; length to vent, 8.0; greatest depth, 2.45; diameter of eye, 1.1 millimeters. 
Myomeres, 15 to vent plus 22 behind. Adult characters apparent with completion 
of fins, and addition of more chromatophores on snout, head, and sides of body, giving 
typically blotched appearance; fins still colorless except for a few chromatophores 
near base of caudal. 
35 .0 - millimeter stage. — Small adult female with ripe eggs. 
BREEDING 
The eggs of the Johnny darter are attached to objects usually about a foot or so 
below the surface of the water. The flat undersides of stones are a favorite nest, over 
which the parent fish guards assiduously. The breeding season is in May and June, 
at which time the anterior part of the male becomes very black. 
45. Poecilichthys coeruleus coeruleus (Storer). Rainbow darter; soldier darter; 
blue darter. [Oligocephalus coeruleus (Storer). Jordan, Evermann, Clark, p. 291.] 
RECORD OF CAPTURE 
The rainbow darter is never found in Lake Erie, but frequents the shallow creeks 
of the region, where it is common. 
DESCRIPTION 
Its incomplete lateral line, moderately decurved snout, and anal rays numbering 
12 to 14 differentiate the rainbow from other darters of this genus. 
22. 6 -millimeter stage. — Total length, 22.6; standard length, 19.1; length to vent, 
11.6; length of head, 5.6; diameter of eye, 1.6; greatest depth, 4.0 millimeters. 
Dorsal X, 12; anal II, 7 ; ventrals large, inserted close together. Myomeres, about 15 
to vent plus 21 behind. Body rather stout; head large; lower jaw slightly included; 
premaxillaries not protractile. 
Pigmentation. — Chromatophores are thickly distributed over head with a black 
band extending from tip of snout through eye to back of head. On dorsal aspect 
they are arranged in about 10 blocks crossing ridge and extending down the sides 
somewhat. The chromatophores in these blocks are arranged around outlines of 
scales. On lateral aspect occur about 13 crossbars, narrower than the dorsal blocks, 
neither opposite nor connecting with them. The last bar is darker than the others, 
situated at base of caudal, and it has a dark round spot above and below on dorsal 
