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PACIFIC SCIENCE, VoL XXI, July 1967 
portant that the substrate surface be relatively 
rough in texture, since the adhesive eggs adhere 
only temporarily to a smooth surface such as 
glass or plastic. Old automobile exhaust pipes, 
or muffler tubes, are "preferred” nesting sites 
when available in the environment (as they are 
in the Little Campbell River). 
Females aggregate upstream (about station 
C-3) above the main spawning area and then 
move individually onto the spawning beds where 
they display to, and are courted by, males both 
outside and inside their nests. After a male 
selects a female to occupy his nest, further 
courtship and prespawning behavior occurs 
within the nest. The adhesive eggs are laid in a 
jelly-enclosed cluster on the ceiling of the spawn- 
ing chamber. Ovariotomy of preserved gravid 
females from throughout the distributional 
range of C. asper yielded counts of 336 mature 
oocytes in a 49. 5 -mm S.L. female, to 5,652 
mature oocytes in a female of 119.5 mm S.L. 
The largest female examined was 192 mm S.L., 
but she was spent. A conservative estimate of 
the number of mature oocytes would be about 
10,000 for this female. Numbers of viable eggs, 
in masses collected in the field, varied from 700 
to 4,000 per cluster. However, one male may 
court and successfully mate with as many as 10 
different females (personal observation). As 
many as 10 egg masses, in varying stages of 
development from newly-fertilized to near- 
hatching, have been found in the nest of a sin- 
gle brooding male. An estimated 25,000-30,000 
eggs were present in this one nest. 
After spawning, the spent females leave, or 
are chased from, the nests and they again aggre- 
gate above the spawning areas and begin feed- 
ing. The males remain in the nests, fanning and 
protecting the eggs, and do not eat until hatch- 
ing of all egg clusters is completed. Much of 
the courtship and prespawning behavior, as well 
as most of the paternal brooding behavior 
through hatching, has been documented and 
will be reported elsewhere. 
Laboratory studies on the behavior of C. asper 
larvae, done in extension of salinity-tolerance 
experiments (also to be reported elsewhere), 
indicate that at 12° C the larvae 5-7 mm in 
total length begin swimming immediately upon 
hatching. They remain pelagic, as lightly- 
pigmented transparent larvae, for a period of 
30-35 days before metamorphosing and settling 
to the bottom. 
Figure 5 Illustrates numbers and distribution 
of C. asper young-of-the-year, 12-25 mm S.L., 
taken in a total of 700 seine hauls. In late spring 
and throughout the summer, the newly meta- 
morphosed young-of-the-year are found in great 
numbers around and below the spawning site. 
The concentration is greatest around station C- 
1A, where there is a bed of fine, pea-size gravel 
adjacent to a large oyster bed. In mid-summer, 
there is a definite upstream migration of the 
young-of-the-year. In both I960 and 1961, the 
increasing abundance of young-of-the-year at 
stations C-4 and C-5 was correlated with the 
decreasing abundance of specimens In the estu- 
arine areas of the river (Fig. 5). 
Spawning Period and Temperature 
Relationships 
Egg clusters were collected from several lo- 
calities in the lower Fraser Valley (cf. Fig. 1) 
and in the Little Campbell River. Gonads were 
examined in over 1,100 preserved museum spec- 
imens from all latitudes within the distribu- 
tional range of C. asper. These data indicate 
that egg deposition begins in the south of the 
distribution range (low latitudes) in February, 
and progresses northward until late July. Males 
usually attain full reproductive maturity about 
a month before, and remain in spawning condi- 
tion for almost a month after, the period of 
oviposition in females. Gravid females have 
been found over a 4- week period in Squakum 
Lake, and a 6-week period in the Little Camp- 
bell River. Ripe males have been taken over an 
8-12 week period, respectively, in these same 
localities. 
The earliest date on which a ripe male, in 
nuptial dress and with flowing sperm, was col- 
lected is February 6, in San Francisco Bay. The 
earliest collection of gravid females was In 
Waddell Creek, California, on February 24. In 
the north end of the range, gravid females 
were taken as late as June 20 in Petersen Creek, 
near Juneau, Alaska, and on July 22 in streams 
entering Juskatla Inlet, Queen Charlotte Is- 
lands. Gravid females have also been collected 
from Middle River, near Takla Lake, on June 
28, and from Meziadin Lake, B. C, on July 25. 
Field records and personal observations indi- 
