Effect of salinity on hypoxia tolerance of resting green crabs, Carcinus maenas, after feeding
Legeay, A.; Massabuau, J.-C. (2000). Effect of salinity on hypoxia tolerance of resting green crabs, Carcinus maenas, after feeding. Mar. Biol. (Berl.) 136(3): 387-396. http://dx.doi.org/10.1007/s002270050698
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, more
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| Authors | | Top |
- Legeay, A.
- Massabuau, J.-C.
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| Abstract |
Mechanisms that can influence the tolerance of hypoxia in brackish waters were studied in resting and fed crabs, Carcinus maenas, at 15?°C. Mortality, blood oxygenation, acid-base status and lactate concentration were analysed in fed crabs held in full-strength normoxic seawater (32.5‰?S) and then transferred for 24?h to a partial pressure of oxygen (Po2) of 3?kPa (1.4?mg?l-1) and various salinities (17, 12.5, 10, 8‰?S). At salinity levels >10‰, fed crabs tolerated Po2 values as low as 3?kPa in the ambient water and 0.5?kPa in their arterial blood for 24?h without switching to anaerobic metabolism. Only below 10‰?S did their blood-lactate content rise, leading to their death despite the fact that their blood O2-content was twice the control value measured in full-strength normoxic seawater and their blood Po2 did not decrease below values recorded at higher salinity levels. Addition of CO2 to 8‰?S water (CO2 partial pressure increasing from 0.1 to 0.3?kPa) decreased blood-lactate production and mortality, suggesting that at 10‰?S impairment of the O2 supply is limited by an excessive blood O2-affinity. The results are discussed in terms of the distribution (?10‰?S) of C. maenas along salinity gradients in estuaries and bays. |
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