30 
from decreasing photo-periods to that of in- 
creasing photo-periods; and that there is some 
correlation between deposition of brood number 
one and increase in water surface temperature. 
However, these suppositions need a considerable 
amount of research to test their validity. 
COPULATION: No data as to the time, method, 
or frequency of copulation were obtained. 
OOGENESIS AND EGG DEPOSITION: The exact 
time at which oogenesis begins is not known, 
but a projected curve suggests that it begins 
in October. By early November some of the 
ovaries show considerable development of the 
ova, while others have ova ranging around 0.015 
mm in size. However, by the end of November 
those few specimens examined had ova averag- 
ing about 0.35 mm in diameter and bearing 
a yellow-orange pigment. By the end of January 
most of the ova measured about 0.68 X 0.60 
mm. Throughout February there is a very slight 
increase in size until deposition occurs. Figure 
7 shows the season of egg deposition for both 
the first and second broods as far as our data 
will permit. From the latter part of February 
until mid-April egg deposition occurs rapidly 
but then begins to taper off until the middle of 
May, when over 97% of the females have eggs. 
Hatching begins toward the end of May and 
continues until the first week of August, when 
the last of brood number one hatches. Brood 
number two begins before the first of June and 
egg deposition is rapid until the early part of 
August, when from 74 to 80% of the females 
carry new eggs. From here a theoretical curve 
would show that hatching follows very quickly 
and that brood number two probably is com- 
pleted by the end of September or the early part 
of October. It is possible, therefore, that oogen- 
esis may begin again while brood number two 
is still carried on the pleopods. 
PRODUCTIVITY: The number of eggs carried 
by 37 different females was determined. Cara- 
pace length ranged from 6.9 mm to 13.6 mm. 
Broods ranged from only 10 eggs in the smallest 
individual to 1,580 in the largest specimen. The 
average count for 37 individuals was 621 per 
brood. If each female produced two broods per 
year, a total of about 1,250 would be produced. 
Considering that only up to 80% of the females 
produce a second brood, a more accurate annual 
production for all females would be about 1,100 
PACIFIC SCIENCE, Vol. XVIII, January 1964 
eggs per year. The extremely large size of the 
egg of this species (about 0.75-0.80 mm) dem- 
onstrates that a larger larval form is produced, 
which theoretically could better fend for itself 
and thus lessen the danger of predation and 
starvation. 
Pachycheles rudis 
HABITAT: The habitat of Pachycheles rudis 
is below the minus-zero tide level where water 
currents are strong, in such places as are listed 
by Haig (1960:172): under stones, the hold- 
fasts of kelp, in sponge cavities, among rock 
oysters and mussels, in tunicate beds, and in 
the discarded burrows of dead burrowing clams. 
MacGinitie (1935:712) states that males and 
females live together in pairs. This species was 
taken on occasion under rocks with P etrolisthes 
eriomerus at the Tacoma Narrows. It was found 
in great abundance, however, at Port Orchard, 
in the situations cited by Haig. Most frequently 
pairs were found within the empty burrows of 
rock-burrowing clams ( Petricola ) . The size of 
the animals within the burrows often seemed 
much greater than the outer aperture of the 
burrow. When the burrows were opened with 
a geological pick larger specimens seemed unable 
to escape by means of the normal aperture, or 
else were reluctant to do so. It is suggested that 
young pairs occupy these burrows, feed on 
plankton and grow, reproduce, and continue 
their existence until they have reached a size 
much greater than the tapered burrow opening. 
Specimens brought to the Point Defiance labora- 
tory would occupy any small cavity provided, 
such as small vials, cones made out of screen 
wire, and empty shells. Animals removed from 
these artificial chambers again proved to be in 
pairs. In the laboratory this species was ex- 
tremely sensitive to the oxygen content of the 
water. If the running sea water was shut off 
within the 30-gal tanks for a period of several 
hours, death occurred, and increased as time 
progressed. This species was more sensitive in 
this respect than the other crab-like Anomura 
we worked with, and the Anomura in turn 
proved to be more sensitive than the Brachyura. 
REPRODUCTIVE ACTIVITY: Our field records 
for P. rudis from the middle of December 
through August show that between 75 and 100% 
