SIXTY-TWO SPECIES OF FISHES FROM LAKE ERIE 373 
43. Rheocrypta copelandi Jordan. Copeland’s darter. [Cottogaster copelandi, 
(Jordan). Jordan, Evermann, Clark, p. 285.] 
RECORD OF CAPTURE 
Although this is a common species in Lake Erie and the larger tributaries, only 
one larva taken by the survey can be assigned even tentatively to it. This was a 
7-millimeter specimen taken on June 7, 1929, in 12 meters near Point Abino on the 
Ontario shore. The fact that many adults seek streams in which to spawn probably 
accounts in this species, as in many others, for the scanty number of young found 
in the lake towings. The older specimen described below was captured at the mouth 
of Cattaraugus Creek in late August. 
DESCRIPTION 
Concerning the older stages the color pattern of many darters is so similar that 
it fails to be useful as a field character. However, there are certain definite differences 
which careful examination will disclose. In the first place, the premaxillaries of this 
species are protractile, distinguishing it from Hadropterus and Percina, and the mid- 
line of belly has a single series of enlarged, spinous scales which are lacking in Imos- 
toma and Ammocrypta and others. The color pattern and general characters resemble 
Boleosoma closely, but the latter has only 1 instead of 2 anal spines, its belly is covered 
with normal scales, and the anal fin is shorter than the second dorsal. 
6.1 -millimeter stage. — Total length, 6.1; length to vent, 2.6; length of head, 1.2; 
snout, 0.25; diameter of eye, 0.26; greatest depth before vent, 1.0; depth behind vent, 
1.1 m i l l imeters. Myomeres, 14 to vent plus 24 behind. Moderate marginal fin 
fold, alike above and below, originating in vent region; pectorals large, not reaching 
quite halfway to vent. Vent located away from body, at ventral margin of fin fold. 
Although traces of the yolk still are present, the intestine is large and coiled. It 
differs from Lota of like size taken simultaneously in the less deep head, smaller 
eye, absence of air bladder, and especially in the fewer number of myomeres in tail. 
Coitus is suggested in general shape and myomere count but it is much smaller than 
a sculpin of like development. The body is sturdier than in the comparatively 
elongate Perea flavescens, which species, too, is recognized by its pigment series. 
Pigmentation. — The 6.1 -millimeter larva is entirely colorless except for its 
dark eye. 
43.0 millimeter stage. — Total length, 43.0; standard length, 35.8; length to vent, 
22.2; length of head, 8.5; snout, 2.5; diameter of eye, 2.6; greatest depth, 6.0; length 
to first dorsal, 11.5; to anal, 22.4 millimeters. Vertebrae, 18 plus 20. Dorsal XI, 
12; anal II, 9. Body rather slender, elongate; head large and long, resembling 
Boleosoma, with small, subinferior, horizontal mouth and protractile premaxillaries. 
Mid-line of belly with single series of enlarged, spinous, thickened scales. 
