362 
BULLETIN OF THE BUREAU OF FISHERIES 
Family PERCID/E, Perches 
38. Perea flavescens (Mitchill). Yellow perch. 
RECORD OF CAPTURE 
Young of this very common Lake Erie species were taken abundantly during the 
middle of July, 1928, from Bertie Bay on the Canadian shore to Angola in Helgoland 
and meter-net towings from 0 to 4 meters below the surface, and again in the middle 
of July a few were captured off Silver Creek. From June 7 to August 6, 1929, great 
numbers of larvae and postlarvae were taken throughout the length of Lake Erie, 
usually inshore in shallow water but sometines even in the very center of the lake. 
So numerous were they off Rondeau in 19 meters of water on June 17, that 118 were 
taken in a 5-minute meter-net towing at 1 meter above the bottom. A fully devel- 
oped young fish, 50 millimeters long, was taken on August 6 on the bottom at 11 
meters depth. 
DESCRIPTION 
The rounded head, large rounded yolk sac with one large oil globule, and pigment 
which spreads from the ventral ridge up a short distance along the myocommata are 
Figure 84 . — Perea flavescens, 5.6 millimeters 
constant early larval characters, and the serrated preopercle, lack of canine teeth, 
oblong compressed body with ventrals close together distinguish the later stages. 
Egg . — The eggs of the yellow perch are spawned in a long tube-shaped mass, 
closed at the ends and folded like the bellows of an accordion. The mass contracts 
to a length of less than a foot through this folding, but can be stretched out 3 or 4 
times as long. Such a mass was spawned in the Buffalo Musem Aquarium on May 
26, 1930, but inability to procure a ripe male made einbryological study impossible. 
5 .6 -millimeter stage . — Total length, 5.6; length to vent, 2.75; length of head, 0.75; 
snout, 0.17; diameter of eye, 0.32; greatest depth before vent, 0.93; depth behind vent, 
0.75 millimeters. Myomeres, 18 to vent plus 18 behind (incomplete). Characterized 
by large yolk sac with one large clear yellow oil globule, about 0.4 millimeter in 
diameter, placed anteriorly; embryonic marginal fin fold granular in texture, originat- 
ing dorsally at base of brain and ventrally at middle of yolk sac, moderate in height 
without pronounced elevation; pectorals well developed. 
Pigmentation. — The eye is very dark. Sparsely distributed large light-colored 
stellate chromatophores occur on bottom of yolk sac and usually one or more on dorsal 
and ventral aspects of intestine. An uneven series of very small unequal chromato- 
phores is evident ventrally behind the vent, and the divisions of the myomeres (few 
or all depending on the individual) are marked by black pigment lines running from 
ventral edge to lateral line. 
7.3-millimeter stage . — Total length, 7.3; length to vent, 3.6; greatest depth, 0.95; 
diameter of eye, 0.45 millimeter. Mouth terminal, slightly below mid-line; yolk 
much absorbed with one large, oval, yellowish oil globule occupying the anterior part; 
