Specific protein responses in the calanoid copepod Eurytemora affinis (Poppe, 1880) to salinity and temperature variation

The distribution of the calanoid copepod Eurytemora affinis (Poppe, 1880) i n the Chesapeake Bay seems to be limited by salinity and temperature. Resul ts in the laboratory suggest it should be able to accommodate to the entire range of salinity-temperature combinations encountered. Yet, at high tempe ratures and salinities, in particular, E. affinis is not found. In this stu dy, we examined changes in protein expression in E. affinis exposed to extr eme temperature-salinity combinations as well as to salinity-temperature co mbinations where they are found in the Chesapeake Bay. The protein changes observed were specific to treatment. The number of proteins present or abse nt compared to intermediate conditions tended to increase with the degree o f stress. Some of these proteins may be involved in regulation of free none ssential amino acids or have direct interaction with inorganic ions. (C) 20 01 Elsevier Science B.V. All rights reserved.