Osmoregulation in Estuarine Crabs: Using Cell and Molecular Biology, but Remembering the Whole Organism
Don Lovett, Department of Biology, The College of New Jersey
18 Nov 2005
The Atlantic blue crab, Callinectes sapidus, is a strong hyper-osmoregulator in dilute seawater. Although it has been known that a number of cellular and physiological changes occur when the crab acclimates to low salinity, most studies have compared crabs acclimated to low salinity with crabs acclimated to high salinity. Specifically, acclimation to low salinity is accompanied by a dramatic increase in the activity of Na+,K+-ATPase in the gills, the primary organ for osmoregulation, and changes in the ultrastructure of cells in the gills. Both of these changes are preceded by up-regulation of some genes. However, early studies failed to detect changes in gene expression because only fully-acclimated animals were examined. These findings have led us to examine a number of short-term and long-term mechanisms that may be involved in modulating the crab's response to changes in salinity.