Respiration and osmoregulation of the estuarine crab, Rhithropanopeus harrisii (Gould): effects of the herbicide, alachlor.

1. The effects of a sudden decrease in salinity and exposure to sublethal concentrations of the herbicide, alachlor, on osmoregulation and respiration of the crab, Rithropanopeus harrisii, were studied. 2. Crabs were hyperosmotic regulators at salinities below 24 ppt and became hypoosmotic at higher salinities. Upon a salinity decrease from 20 to 1 ppt, crabs adjusted their haemolymph osmolality to a stable hyperosmotic level in 8 hr. Alachlor concentrations to 50 ppm did not affect this adjustment. 3. A salinity decrease from 10 to 0 ppt elevated VO2 and the critical oxygen tension. This response was unaffected by alachlor concentrations as high as 25 ppm.

Duke Scholars

Author Richard B. Forward Marine Science and Conservation