Systematics of Prickly Sculpin, II — Krejsa 
lakes and streams relatively close to the sea, 
where access to the sea is open and relatively 
easy to achieve, do not migrate seaward. They 
also undertake only local movements and spawn 
within the fresh-water system in which they are 
found. Such primary differences in behavior, 
correlated with distinct differences in prickling 
patterns, geographical distribution, and iodine 
metabolism, further corroborate the contention 
that "coastal” and "inland” forms of C. asper 
are genetically distinct. 
Figure 5 shows a lag of about two months 
in the appearance of young-of-the-year C. asper, 
12-25 mm S.L., after the first recorded spawn- 
ing in March. Water temperatures in March 
are normally from 8° to 10° C. Eggs spawned 
early in March probably have an incubation 
period several days longer than the 15-16 day 
period found to be typical at 12° C in the 
laboratory. The lag shown in Figure 5 probably 
is due to an incubation period of 3 weeks 
followed by a pelagic larval stage of 4-5 weeks. 
Plankton tows taken during late April in the 
shallow back-eddies of the stream have captured 
a few larvae 9-10 mm S.L. (not recorded in 
Kg- 5). 
An upstream migration of adults precedes 
that of the young-of-the-year in late summer. 
This is probably related to the food habits of 
the two groups and also to the fact that a 
later return of the young-of-the-year coincides 
with lower water levels in the stream, when re- 
duced water velocity facilitates access upstream. 
The usual spawning temperature range for 
C. asper is from 8° to 13° C. It is assumed 
that in most populations spawning is initiated 
within this 5° range of temperature, which pro- 
ceeds in somewhat of a thermal "wave” from 
south to north in both inland and coastal locali- 
ties (Fig. 6). This is not to say that they all 
spawn at the same temperature within the range. 
Furthermore, because the monthly rate of in- 
crease of ambient temperature is greater in the 
north, the duration of exposure of prickly scul- 
pin eggs to any given temperature within the 
5° C temperature range may be shorter. Eggs 
subjected to these conditions presumably would 
have a faster development than eggs which de- 
veloped under relatively more thermostable con- 
ditions, such as occur in the south of the dis- 
tributional range. Low meristic counts are gen- 
421 
erally (although not invariably) associated with 
faster rates of development. An experimental 
analysis of temperature-determined morpholog- 
ical differences is needed, especially of meristic 
differences, between "coastal” and "inland” 
populations of C. asper at the same latitude and 
between fishes from the north and south ends 
of their respective ranges. The implications and 
the desirability of such studies in determining 
the validity of the proposed genetic distinction 
between "inland” and "coastal” populations are 
obvious. The existing meristic evidence (Krejsa, 
1965) is equivocal. 
SUMMARY 
1. The stream studied, the Little Campbell 
River, is a small coastal stream, the lower 
mile of which is subject to tidal inundation of 
mixohaline waters. 
2. In late winter and early spring, the adults 
and juvenile prickly sculpins migrate down- 
stream to the estuarine region of the Little 
Campbell River, the only region in the lower 
4 miles in which suitable spawning substrate is 
available. 
3. Males set up nesting sites under large 
cobbles and rocks, and courtship occurs both 
outside and within the nest. 
4. Spawning occurs from March throughout 
early May. 
5. Newly-hatched larvae begin swimming 
immediately and remain pelagic for a period of 
30—35 days before metamorphosing and settling 
to the bottom. 
6. In May, metamorphosed young-of-the- 
year (approximately 12 mm S.L.) begin appear- 
ing only in those collections taken in the estu- 
arine portion of the river. They occur in great 
abundance until September, when the numbers 
decrease in the estaury and increase in upstream, 
nones tuarine waters. 
7. During the nonmigratory phase of its life 
history, the prickly sculpin population in the 
Little Campbell River is distributed primarily 
in the low gradient, low velocity, portions of 
the stream. 
8. Within any given population of prickly 
sculpins, the males are reproductively active 
longer, in a given season, than the females. The 
period of reproductive activity of both sexes is 
