Fig. 4.—Pigmentation patterns 
f breeding male and female 
'ercina sciera. 
id June less than 40 mm lacked mature eggs, but 
rger yearlings collected at the same time and place 
tained mature eggs and appeared ready to spawn. 
The reproductive cycle of the female was divisible 
to a prespawning period, the spawning act, and post- 
awning period. The prespawning period was charac- 
rized by the differentiation and maturation of ova, 
€ spawning act by the release of mature eggs, and the 
stspawning period by absorption of the remaining 
/a and recovery of the ovaries. 
Two characteristics of ova maturation — size and 
lor — were easily observable and allowed the devel- 
ing Ova to be categorized. The ova were all small in 
e earliest stages of maturation, but in late spring 
1en development was most rapid the ova were con- 
tently present in three different size groups: less than 
mm, between .6 and 1.0 mm, and from 1.1 to 1.5 
m in diameter. The smallest ova were white, the inter- 
ediate ones were yellow, and the largest were dark 
llow or orange. 
Percentages of differentiated ova (Table 1) were 
Sed on estimates rather than actual counts but the 
iimates were consistently made and are comparable. 
1€ prespawning period began when the ova first 
gan to differentiate in early October. A specimen 
llected in September had almost no ova that could be 
issed as differentiated, but one collected on October 
had an estimated 10 percent of the ova differentiated, 
hough they were still white and less than .5 mm in 
ameter. The initiation and progression of ova devel- 
ment may vary with the size and age of the fish and 
ssibly with climatic conditions. 
Early stages of differentiation proceeded slowly, and 
My / 
“yy, 
VA pag, 
TaBLe 1.—Differentiation and growth of ova in Percina sciera 
collected in the study area between August 4, 1967, and June 8, 1969. 
Percent of Differentiated 
Ova by Size Group 
Date of Hstimated Percent of .1-.5 .6-1.0 1.1-1.5 
Collection Differentiated Ova mm mm mm 
Oct. 14 10 100 0 0 
Nov. 1 15 100 0 0 
Dec. 7 25 100 0 0 
Feb. 23 80 92 8 0 
Mar. 29 75 69 31 0 
April 28 over 90 64 25 11 
May 15 over 90 64 24 12 
June 25% over 90 60 26 14 
July 7* over 90 56 24 20 
Aug. 4 10 100 0 (0) 
Sept. 21 0 0 0 i) 
® 1968 only; in 1969 Percina sciera spawned in early June. 
not until the water warmed and spawning time ap- 
proached did recognizably mature eggs appear (Fig. 5). 
Examination of a specimen collected on March 7 indi- 
cated that as many as 90 percent of the ova had 
differentiated but all were white and less than .5 mm, 
just as those of the October specimen had been. 
A specimen collected on April 28 contained ova 
clearly divisible into the three size and color categories 
mentioned above (the smallest ova were white and 
less than .5 mm in diameter, the intermediate ova 
yellow and between .6 and 1.0 mm, and the largest 
orange and between 1.1 and 1.5 mm). Sixty-four per- 
