878 
Fishery Bulletin 96(4), 1 998 
nj 
E 
CD 
OJ 
LU 
60 
50 
40 
30 
20 
10 
100 150 200 250 300 
Branchial volume (mL) 
Figure 7 
Volume of single egg masses as a function of the 
volume of the branchial chambers of the host crab. 
ro 
E 
cr> 
O) 
a> 
200 
400 600 
800 
200 
400 
600 
800 
Depth (m) 
Figure 8 
Number of egg masses by 100-m depth intervals for pink 
snailfish (solid line) and red snailfish (dotted line, up- 
per). Incidence, or proportion of all crabs having snailfish 
eggs or larvae of either species, by 100-m depth interval 
(lower). 
Table 2 
Summary statistics of the fitted logistic models. 
Model 1 (1982 survey data) 
logit( incidence) = intercept + sex + length 
h depth + 
depth 2 + sex*depth + 
sex x depth 2 
Coefficient 
Value 
Intercept 
-8.6724639 
Sex 
-2.2823274 
Length 
0.0261672 
Depth 
0.0310400 
Depth 2 
-0.0000432 
Sex x depth 
0.0187658 
Sex x depth 2 
-0.0000512 
Significance tests of main effects 
Effect Likelihood ratio 
df 
Probability 
Length 8.87 
1 
0.003 
Sex 25.02 
3 
<0.001 
Depth 20.92 
4 
<0.001 
Model 2 (1996 port sampling of commercial catch) 
logit( incidence) = intercept + 
area + dead 
or alive 
Coefficient 
Value 
Intercept 
-2.744489 
Area 
-0.667367 
Dead or alive 
-0.300833 
Significance tests of main effects 
Effect Likelihood ratio 
df 
Probability 
Area 22.39 
1 
<0.001 
Dead or alive 3.96 
1 
0.046 
carrying uneyed embryos (Table 4). As crab embryos 
became more developed, so too did the snailfish em- 
bryos. Thus, crabs with eyed embryos were not found 
with uneyed snailfish embryos, and crabs with 
hatched embryos were not found with uneyed or eyed 
snailfish embryos. Considering the three develop- 
ment stages of both species as an ordered random 
variable, the crab developmental stages were highly 
correlated (rho=0.68, P=0.005) with the snailfish 
developmental stages. 
Genetic determination of species identity 
All 14 of the fish samples, but only 10 of the 23 egg 
and larvae samples, collected by commercial fishery 
observers were sufficiently well preserved to allow 
