Cadmium, zinc and the uptake of calcium by two crabs, Carcinus maenas and Eriocheir sinensis
In: Aquatic Toxicology. Elsevier Science: Tokyo; New York; London; Amsterdam. ISSN 0166-445X; e-ISSN 1879-1514, more
Also appears in:Grosell, M.; Brix, K.V. (Ed.) (2005). Mechanisms in metal toxicology. Aquatic Toxicology, 72(1-2). Elsevier: Amsterdam. 3-176 pp., more
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| Keywords |
Chemical elements > Metals > Alkaline earth metals > Calcium
Chemical elements > Metals > Heavy metals > Cadmium
Chemical elements > Metals > Heavy metals > Zinc
Crabs
Crabs
Invertebrates > Arthropods > Crustacea > Malacostraca > Decapoda > Shellfish > Crabs
Uptake
Carcinus maenas (Linnaeus, 1758) [WoRMS]; Eriocheir sinensis H. Milne Edwards, 1853 [WoRMS]
ANE, British Isles, Scotland [Marine Regions]
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| Author keywords |
uptake; cadmium; zinc; calcium; crabs; Carcinus; Eriocheir |
| Authors | | Top |
- Rainbow, P.S.
- Black, W.H.
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| Abstract |
The uptake of dissolved cadmium and zinc by crustaceans can usually be explained by the passive process of facilitated diffusion involving a transport protein in the membranes of permeable surfaces. Cadmium ions will also enter via uptake routes for calcium, given the similar size of the two free ions. This study has investigated the interaction of cadmium (and comparatively zinc) and calcium uptake in two crabs that show different permeability responses to changes in salinity, with consequently different effects on the uptake of cadmium and zinc with salinity change. Ca uptake rates in Carcinus maenas decreased in reduced salinity (33–15) with the decreased Ca concentration of the medium and increased if the Ca concentration was increased at salinity 20. It is concluded that Ca uptake over the salinity range 33–15 is via apical Ca channels in gill ionocytes, passively down an electrochemical gradient. The Ca uptake rate of Eriocheir sinensis showed no significant decrease over the salinity range 33–10 (probably because of the small differences in an already low Ca uptake rate in this crab against a background of inter-individual variability), but decreased significantly at salinity 5. Added calcium increased the Ca uptake rate of E. sinensis at salinities 15 and 5, supporting the interpretation that Ca uptake in gills is typically passive via apical Ca channels. Cadmium (but not zinc) inhibited calcium uptake in both crabs at 15 salinity, indicating sharing of Ca channels by Cd, but not at salinity 5 (E. sinensis only) when Ca may be taken up into gill ionocytes by another (active?) physiological process. |
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