12 
TABLE 4. — Standard lengths of Etheostoma squamiceps at 1, 2, and 3 years (12, 24, and 36 months) of age. These 
specimens were collected in April 1971 and 1973. 
Neen ——— lt 
Study Area 
Bn ae Age Number 
Big Creek males 1 15 
Big Creek females il 22 
Ferguson Creek males 1 3 
Ferguson Creek females al 21 
Big Creek males 2 17 
Big Creek females 2 33 
Ferguson Creek males 2 2 
Ferguson Creek females 2 4 
Big Creek males 3 5 
Big Creek females 3 3 
Ferguson Creek males* 3 2 
a No 3-year-old females were found in Ferguson Creek. 
contrast to the mottled pattern of adults, they had 
a pattern consisting of large spots over all areas of 
the body except the belly. At 16 mm the lateral-line 
canal had begun to form. At 19 mm the mottled 
pattern characteristic of the adult was present, scales 
were present on the nape, breast, and belly; and 
the lateral line extended to the soft-dorsal fin. 
Both populations studied grew at nearly the same 
decreasing rate (Fig. 9). The equation expressing 
the relationship between standard length (Y) and 
age in months (X) of Big Creek males is Y — —7.00 
51 49.83 log X Mere U.900, mecre Ee Creek females 
is Y = -0.35 + 34.21 log X, r = 0.962; of Ferguson 
Creek males is Y = —3.08 + 41.99 log X, r — 0.921, 
and of Ferguson Creek females is Y = 3.19 + 34.92 
log X, r = 0.947. 
During the first year of growth sex had little 
influence on the growth rate. During subsequent 
years, however, males grew more rapidly than did 
females (Fig. 9), and by the third year males were 
significantly larger than females (t = 3.78, ue = a 
for the Big Creek population; t = 2.79, df = 27 for 
the Ferguson Creek population). Males in younger 
year classes were not significantly larger than females. 
The largest specimen examined was a 72-mm male 
from Ferguson Creek. Table 4 presents the standard 
lengths of 1-, 2-, and 3-year-old E. squamiceps col- 
lected in April. 
E. squamiceps reached one-half of the first year’s 
mean growth in approximately 12 weeks; this period 
is much longer than that required for E. gracile 
(1 week, Braasch & Smith 1967:9) and Percina 
phoxocephala (2 weeks, Page & Smith 1971:9). 
Although captive E. squamiceps individuals oc- 
casionally swam up and down the side of an aquarium 
seeking to escape, the species in general has almost 
totally. benthic habits. Both field and aquarium ob- 
servations indicated that the fry, juveniles, and adults 
mainly rest on the substrate or dart about in short, 
Standard Length 
Standard 
Mean Range Deviation 
34.8 27.1-43.2 4.1 
36.2 28.0—43.1 4.1 
Sie 27.4-46.7 on 
37.2 31.9-44.6 4.0 
51.3 43.3-59.8 4.4 
45.5 37.9-55.3 4.4 
57.5 51.4-63.5 8.6 
54.7 48.0—55.6 4.9 
61.2 53.5-65.9 5.4 
57.4 56.2-58.7 ee 
64.6 62.3-66.9 ore 
jerky movements. The only rapid swimming observed 
in the field were escape maneuvers, which usually 
involved distances of less than 2 m. 
DEMOGRAPHY 
Density 
On four separate dates at approximately 3-month 
intervals, quantitative samples of E. squamiceps were 
taken in both Big and Ferguson creeks by repeatedly 
seining a measured area of stream until no more 
darters were collected. The number of specimens 
collected was transposed into the number per square 
meter (Table 5). 
In Big Creek the highest density of adults was 
consistently found in the slab pools. In Ferguson 
Creek the highest densities of adults during the 
nonspawning season were in the slab riffles and in 
April were in slab pools, where they had moved to 
spawn. 
Young darters in Big Creek were common in 
both slab pools and riffles in summer and autumn, 
but common only in the slab pools in winter and 
spring. Young in Ferguson Creek were consistently 
most common in the slab riffles although at 1 year 
of age many had moved to the slab pools where the 
spawning activity was greatest. 
Including both young and adults, the greatest 
density of E. squamiceps in Ferguson Creek (9.6 
per m?) was in the slab riffles in July, and in Big 
Creek the greatest density (2.0 per m*) was in the 
slab pools in April. 
Composition 
Of the 601 E. squamiceps collected in Big Creek, 
55.7 percent were up to | year of age, 34.6 percent 
were over | and up to 2 years of age, 9.2 percent were 
over 2 and up to 3 years, and 0.5 percent were Ove 
3 years. Of the 430 specimens collected in Ferguson 
