Moiseev et ai: Effects of pot fishing on the physical condition of Chionoecetes opilio and Chionoecetes bairdi 
241 
A 
C 
Figure 6 
Changes in mean hemocyanin concentration 
[He] in snow crab ( Chionoecetes opilio ) and 
southern Tanner crab (C. bairdi) after starva- 
tion in crab pots. Open bars indicate mean [He] 
observed in crabs sampled immediately after 
capture (9 individuals for snow crab and 5 for 
southern Tanner crab for each experiment), 
and shaded bars indicate mean [He] observed 
in crabs sampled after starvation (5 individuals 
for snow crab and 9 and 5 for southern Tanner 
crab for experiments with pot soaking time of 
25 days and 55 days, respectively): (A) southern 
Tanner crab, pot soaking time=25 days, Bering 
Sea (area I), 7 July-2 August 2008; (B) south- 
ern Tanner crab, pot soaking time=55 days, 19 
September-12 November 2008, Sea of Okhtosk 
(area I); and (C) snow crab, pot soaking time=55 
days, 19 September-12 November 2008, Sea of 
Okhtosk (area I). An asterisk (*) indicates val- 
ues were significantly different by Student’s 
t-test (PcO.001), compared with mean [He] ob- 
served in crabs immediately after capture. Error 
bars indicate ±1 standard error of the mean. 
In experiment 9, pots soaked for 55 days. At the end 
of this experiment, mean [He] in southern Tanner crab 
decreased by 44% compared with mean [He] in control 
crab immediately after capture (Fig. 6B), but the differ- 
ence between the experimental and control animals was 
not significant (Student’s t-test, P>0.05). In snow crab, 
mean [He] decreased by 67% compared with mean [He] 
in control crab (Fig. 6C), and the difference was signifi- 
cant (Student’s t-test, P<0.001). 
During experiment 4, 2 crab died. At the end of the 
remaining experiments, all experimental animals were 
alive and their vitality was high (VI=2-3). At the end 
of all experiments, the weight of experimental crabs 
and the amount of meat in crab limbs did not change 
significantly. 
Effects of long-term exposure to air on snow crab 
In experiment 10, after long-term exposure to air, the 
vitality of snow crab was low ( VI=0 — 1) and mean [He] 
in these animals was comparable with the mean [He] 
in control crabs immediately after capture. After long- 
term exposure to air, most of the crab that were sub- 
jected to the pot-hauling process were dead after the 
first pot-hauling event. Some individuals were able to 
survive 2-3 pot hauls (Table 1). Samples of hemolymph 
could be obtained from crab only after the first pot 
haul. [He] in hemolymph of those animals was compa- 
rable with the mean [He] in control crab immediately 
after capture. 
Histological investigations 
In our experiments both control and experimental ani- 
mals were hauled from the water in the pot at least 
once and, therefore, gas embolism was observed in 
hearts and gills of both control and experimental ani- 
mals during gross examination of dissected crabs (Fig. 
7). Histopathological investigations found intact and de- 
formed gill lamellae in both experimental and control 
individuals of snow crab and southern Tanner crab (Fig. 
8, A and B; Fig. 9, A-C). Hemolymph spaces of deformed 
gill lamellae were greatly expanded, sometimes in the 
form of vesicular swellings, or, conversely, the opposite 
walls of lamellae were stuck together (Fig. 9A). Often 
the connections of pillar cells in dilated parts of lamel- 
lae were torn (Fig. 9B). Marginal canals had irregular 
shapes or were swollen and filled with a large number 
of hemocytes. Opposite walls of lamellae under the mar- 
ginal canals, as a rule, were stuck together (Fig. 9C). 
Gas bubbles and aggregations of hemocytes were found 
in the myocardia of individuals of both experimental 
and control snow crab and southern Tanner crab. Simi- 
lar changes often were observed in antennal glands, in 
skeletal muscles, and in connective tissues of the stom- 
achs and guts of crabs. Infiltrations of hemocytes and 
different-size, melanized inclusions often were found in 
the gill lamellae of both control and experimental crabs 
(Fig. 9D). We were unable to find or show dependence 
