238 
Fishery Bulletin 111(3) 
Table 2 
Dates, locations, depths, hauling conditions, and sampling for histology during repeated pot hauls in experiments conducted in 
2010 to study the effects of commercial pot fishing on the physical condition of snow and southern Tanner crabs ( Chionoecetes 
opilio and C. bairdi ) in the Bering Sea and in Russian waters of the Sea of Okhotsk. 
Total number of 
crabs sampled 
for histology 
Experiment 
number Year 
Date 
Areas 2 
Depth 
(m) 
°C at 
depth 
Hauling 
intervals 
min/max 
(day) 
Duration of 
experiment 
(day) 
No. of 
pot lifts 
Crab 
species 
Imme- 
diately 
after 
capture 
During 
repeated 
pot 
hauls 
1 
2010 
4-11 Sept 
Bering Sea 
170-260 
2.5-3. 5 
2/3 
7 
3 
C. opilio 
3 
5 
area II 
C. bairdi 
3 
5 
2 
2010 
28 Oct- 
Sea of Okhtosk 
230-340 
1.6-2. 5 
2/3 
5 
2 
C. opilio 
3 
5 
2 Nov 
area III 
1 See Figures 1 and 2. 
ner crabs, unlike in many other crabs, flocculent pre- 
cipitate is formed during blood coagulation and can be 
removed easily by centrifugation. 
Histological examinations 
To examine the histopathological condition of organs 
and tissues in crabs that were subjected to repeated pot 
hauls, tissue samples were taken from both crab species 
during repeated pot hauls at time intervals of 2-3 days 
(Table 2). In each experiment, samples were taken from 
5 individuals used in that experiment and from 3 freshly 
caught individuals that served as control animals. Frag- 
ments of internal organs were fixed for 24-40 h with 
Davidson’s fluid (Bell and Lightner, 1988) prepared in 
seawater. After fixation, the samples were transferred 
to 70% alcohol, in which they were kept in the labora- 
tory. This material was further treated with standard 
histological techniques: samples were dehydrated in an 
alcohol series of increasing concentrations, clarified with 
chloroform, and embedded in paraffin. Sections were 
stained with Meyer’s hematoxylin-eosin (Johnson, 1980) 
and slides were examined under an Olympus Al-2 light 
microscope (Olympus Corp., Tokyo, Japan 1 ). 
Ionic composition of hemolymph 
Colorimetric tests (DiaSys Diagnostic Systems GmbH, 
Holzheim, Germany) were used to measure concentra- 
tions of Ca 2+ ([Ca 2+ ]), Mg 2+ ([Mg 2+ ]), and Cl - ([Cl - ]) in 
hemolymph. Concentration of K + ([K + ]) and Na + ([Na + ]) 
were determined by flame photometry (FLAPHO 4, 
Carl Zeiss, Jena, Germany). 
1 Mention of trade names or commercial companies is for iden- 
tification purposes only and does not imply endorsement by 
the National Marine Fisheries Service, NOAA. 
Hemocyanin concentration 
The [He] in the hemolymph of individual crabs was 
estimated with an established spectrophotometric 
method (Nickerson and Van Holde, 1971; deFur et ah, 
1990). An aliquot of serum was diluted by 50 mmol 
L -1 Tris HC1, containing 10 mmol L -1 EDTA, pH 8.9 
(1:39). The absorbance of the resultant mixture was 
measured at 338 nm. The [He] was calculated with 
the extinction coefficient given by Nickerson and 
van Holde (1971), by assuming an average molecular 
weight of 75 kDa for subunits of hemocyanins (He’s) 
from snow crab and southern Tanner crab. 
Electrophoresis 
To estimate the molecular weight of the different sub- 
units of the He’s from snow crab and southern Tan- 
ner crab, sodium dodecyl sulfate polyacrylamide gel 
electrophoresis (SDS/PAGE) was carried out on whole 
hemolymph by using the discontinuous buffer system 
of Laemmli (1970) on slab gels. The stacking gel was 
made of 4.0% and 2.7% acrylamide and bis-acrylamide, 
respectively, with a pH of 6.8, and the resolving gel 
was made of 10.0% and 2.7%, respectively, with a pH 
of 8.8. The samples (10 pg) were run at 4°C and 20 
mA with a tris-glycine buffer (pH 8.3). The gels were 
stained with Coomassie Brilliant Blue (Bio-Rad Labo- 
ratories, Hercules, CA). 
Copper content in the hepatopancreas 
In experiments 6 and 7, which involved repeated pot 
hauls at short time intervals (<3 days), samples of he- 
patopancreas were dissected, after blood was sampled 
(Table 1). Samples of hepatopancreas also were dis- 
sected from southern Tanner crab after starvation in 
