Brachyura and Anomura of Puget Sound — KNUDSEN 
31 
of the females were reproductively active. Egg 
deposition begins in the middle of December 
and continues into the spring and early summer. 
Without a doubt, developing embryos are car- 
ried long after the middle of August, although 
we have no observations for this species from 
that time on. Data suggest that two or three 
broods of eggs may be produced each season. 
The peak of hatching of the first brood is evident 
in April and May, though it may begin in the 
last week of March in some individuals. Fe- 
males carry new, orange colored eggs or "pre- 
hatch” eggs (gray and showing eyes) through- 
out April and May. A study of these animals 
in the first week of May shows that: ( 1 ) almost 
100% of the females with prehatch eggs have 
ovaries swollen with large, bright orange ova 
which will produce the second brood of off- 
spring; (2) about 50% of the females with 
new orange eggs attached to the pleopods have 
ovaries still engorged with bright orange ova 
which may represent brood two or three; and 
(3) about 50% of the females with new eggs 
attached to the pleopods have ovaries holding a 
few to about a half the normal number of ova 
in the bright orange, prefertilized state. These 
data may mean that either some females produce 
a first or late winter-to-spring brood, a second 
or spring brood, and a third or summer brood 
for a total of three broods (usually), or that 
females produce two broods. In the latter case, 
some of them would begin with a winter-spring 
brood and others would begin in the spring, 
thus giving a staggered timing and a seeming 
third brood. Our data show all of the females to 
be ovigerous in late December, thus suggesting 
three broods, but these data are too few to be 
more than suggestive. Eight of 16 females en- 
countered during the first week of August had 
eggs which were classified "almost prehatch,” 
but belonging to the second or new brood, while 
the remainder of the specimens had extremely 
new eggs attached to the pleopods. One field 
datum is of interest here. A single female bear- 
ing extremely new eggs was found to have a 
very soft exoskeleton and had obviously just 
molted. This suggests that the females may molt 
prior to extruding the new brood. 
PRODUCTIVITY: Fourteen females were pre- 
served and the eggs counted. The carapace width 
ranged from 12.0 to 16.8 mm, and the number 
of eggs ranged from 210 to 2,130. The average 
was 928 eggs per brood. This latter figure is 
misleading, in one sense, as to the reproductive 
capacity of P. rudis. O'f the females representing 
all size classes, 43% had large clutches of eggs 
(from 1,175 to 2,130), with an average of 
1,555 eggs per female. The remaining 57% 
had small clutches of eggs (from 210 to 625), 
with an average of 410 eggs per female. Of the 
large-brood females, half were with new eggs 
and half with prehatch eggs attached to the 
pleopods, while all had ovaries completely swol- 
len with bright orange ova. Of the small brood 
females ( 87 % with new eggs on the pleopods ) , 
63% had ovaries with some large orange ova, 
while 37% had ovaries filled with large orange 
ova. These data support the idea that three 
broods may be produced by this species each 
year, but suggest that not all broods are equally 
large that is, roughly proportional to carapace 
size, as is true for the Grapsidae and Xanthidae, 
etc. Rather, any one of the possible three broods 
may be small or large. 
family LITHODIDAE 
Haplogaster mertensii 
HABITAT: Haplogaster is not considered to 
be at all common in the southern Puget Sound 
area. It was collected only at one locality, the 
Tacoma Narrows. There, in the swift moving 
currents, this crab is located under rocks which 
afford good protection, but provide consider- 
ably more room for moving about than would 
be required by Petrolisthes eriomerus. Although 
in its ecological make-up the Port Orchard col- 
lecting site seems to be similar to the Tacoma 
Narrows, this crab is not found there. These 
animals were never collected in abundance, 
eight or nine being a large number for any one 
trip. With very few exceptions all of the speci- 
mens were released at the time of collecting to 
insure a continuous population for study. It is 
possible that currents are necessary in this habi- 
tat to clean debris from under rocks and thus 
insure ample space, and to bring food and oxy- 
gen to this crab. Experimentation has not been 
made as to oxygen requirements of this animal, 
but it seems possible that its restricted distribu- 
tion may be governed by any of the above 
factors, not least of all oxygen. 
