1. 1.

    Measurements of electrical-potential difference (TEP) and Na+ efflux, across the integument have been made for Corophium volutator acclimated to 85 or 15%SW.

  2. 2.

    The TEP of acclimated animals in 85 or 15%SW is l.4mV or 11.1 mV respectively (haemolymph negative). For acclimated animals, unidirectional Na+ efflux is 154.3 nmol mg−1 body weight h−1 in 85%SW [efflux rate constant (k) = 0.70 h-1] and approximately 35.5 nmol mg−1 h−1 in 15%SW (k = 0.50h−1 in 10%SW).

  3. 3.

    The results indicate that Na+ and Clare passively distributed across the ion-permeable (gill) integument of acclimated animals in 85%SW, but that active uptake of Cl, and possibly Na+ also, occurs across the gills of acclimated animals in 15%SW. The ion transport mechanisms appear to effect electroneutral transfers across the gill integumental epithelium.

  4. 4.

    Corophium volutator gill integument has a high permeability to ions; permeability to Na+(PNa) is 7.5×10−8ms−1, and the ratio PCl/PNa is 0.45, for animals acclimated to either salinity. The resistance of the gill epithelium of acclimated animals has been calculated to be 5.3×10−3Ωm2 and 2.0×10−2Ωm2 in 85 and 15%SW respectively.

This content is only available via PDF.