The effects of PCB exposure on the behavior of the shore crab Hemigrapsus oregonensis

• Main Author: Pearson, Walter H.
• Other Authors: Holton, Robert L.
• Language: en_US
• Published: 2012
• Subjects: Crabs
• Online Access: http://hdl.handle.net/1957/28795

The behavior of the shore crab Hemigrapsus oregonensis was assessed with and without exposure to polychlorinated biphenyls (Aroclor 1260). After describing the crab's behavioral repertoire, activity budgets were developed from observations of the time crabs spent in 20 categories of shelter use, posture, and activity while held in habitat replicas with sinusoidal tides of 12.4 hours. Without PCBs exposure female crabs spent more time sheltered and feeding but less time displaying than males. The sexes also differed in the kinds of displays given. For both sexes certain activities prevailed at certain tidal stages. Crabs readily accumulated PCBs from contaminated sand. Whole body burdens reached as high as 190 ppm PCBs and were related to sex and time spent in feeding. In two experiments the primary effect of PCBs exposure upon the activity budgets of both sexes was to decrease the time spent in pre-feeding and feeding behaviors. When given a variety of food types in a third experiment, crabs under exposure shifted from feeding upon PCBs-contaminated sand to uncontaminated food. By changing its feeding behavior Hemigrapsus oregonensis actively reduced the received dose of PCBs and its presumed adverse effects from what they would otherwise have been. === Graduation date: 1977