54 
Fishery Bulletin 109(1 ) 
and crab size. Guillory (1993), one of few to evaluate 
blue crab escape from derelict pots, found an average 
of 45% of crabs that entered pots escaped. This number 
mirrors the 41% escape rate determined in our field 
study, and Guillory acknowledges that his 45% escape 
rate is likely an underestimate because of the number 
of crabs that enter and exit pots during the intermis- 
sion between pot sampling. 
Our mesocosm observations clearly showed the abil- 
ity of blue crabs to freely enter and exit commercial 
crab pots. Crab behavior does not appear to play a 
substantial role in commercial crab trap efficacy, and it 
appears that behavioral dynamics of blue crabs, in re- 
lation to conspecifics, are different when food is acces- 
sible and inaccessible (Clark et al., 1999). This study is 
limited to adult blue crabs at molt stage C. A number 
of factors impact blue crab behavior and catch. The 
observed behavioral patterns exhibited in this study 
might have been different if female crabs or crabs in a 
different molt stage had been used. For example water- 
men in the Chesapeake Bay use male crabs as bait in 
pots to attract peeler females (“peeler” is a term ap- 
plied to shedding crabs caught by soft-shell fishermen) . 
Blue crab behavior effects crab pot catch and escape 
rates. Eighty-five percent of blue crabs that entered 
pots were shown to escape, and escape rates may have 
something to do with the accessibility of food in crab 
pots. However, the behavioral interactions between blue 
crabs were not observed or quantified as impacting 
catch or escape rates. Blue crabs in this study exhib- 
ited few quantifiable aggressive interactions, which is 
atypical of their documented aggressive nature (Clark 
et al. 1999; deRivera et al., 2005). The escape rates 
documented in this study may impact blue crab popula- 
tion dynamics based on CPUE and should be further 
investigated. We also demonstrate that in population 
studies, two species with similar agonistic behavior 
characteristics (such as the American lobster and blue 
crab) can behave differently under similar conditions 
and therefore require species-specific assessments. 
Moreover, we caution against broad generalizations 
about species with perceived similarities in their be- 
havioral characteristics. 
Acknowledgments 
This work was supported in part by the National Sci- 
ence Foundation funded LSAMP grant to K. Clark, and 
by the Smithsonian Environmental Research Center for 
providing research facilities. We also thank G. Abbe 
for a helpful critique and critical discussions. This is 
contribution number 3118 from the Virginia Institute 
of Marine Science. 
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