Survivorship of juvenile surf clams Donax serra (Bivalvia, Donacidae) exposed to severe hypoxia and hydrogen sulphide
Laudien, J.; Schiedek, D.; Brey, T.; Arntz, W.E. (2002). Survivorship of juvenile surf clams Donax serra (Bivalvia, Donacidae) exposed to severe hypoxia and hydrogen sulphide. J. Exp. Mar. Biol. Ecol. 271: 9-23. https://dx.doi.org/10.1016/S0022-0981(02)00030-8 In: Journal of Experimental Marine Biology and Ecology. Elsevier: New York. ISSN 0022-0981; e-ISSN 1879-1697, more |  |
| Keywords | Anoxic conditions
Biology > Physiology > Ecophysiology
Chemical compounds > Sulphur compounds > Sulphides
Chemical compounds > Sulphur compounds > Sulphides > Hydrogen compounds > Hydrogen sulphide
Detoxification
Developmental stages > Juveniles
Diseases > Human diseases > Hypoxia
Environments > Aquatic environment > Benthic environment > Littoral zone
Environments > Aquatic environment > Marine environment > Intertidal environment
Fauna > Aquatic organisms > Aquatic animals > Shellfish > Marine organisms > Marine molluscs
Population dynamics
Population functions > Recruitment
Properties > Biological properties > Toxicity
Survival
Topographic features > Landforms > Coastal landforms > Beaches
Donax serra Röding, 1798 [WoRMS]
PSW, Benguela Upwelling; PSW, Namibia [Marine Regions]; PSW, South Atlantic [Marine Regions]
Marine/Coastal |
| Authors | | Top | - Laudien, J.
- Schiedek, D., more
- Brey, T.
- Arntz, W.E.
| | |
| Abstract | Toxic "sulphide eruptions" sporadically occur in the highly productive inshore regions of the central Namibian Benguela Upwelling system. The surf clam Donax serra (Roeding, 1798) dominates the intertidal and upper subtidal of large exposed sandy beaches of southern Africa and its recruitment seems to be affected by sulphide events. The reaction of juvenile surf clams to low oxygen concentrations and sulphide occurrence (0.1 mmol l -1) was examined by in vitro exposure experiments in a gas-tight continuous flow system. After 2 h of hypoxic- and hypoxic/sulphidic conditions, clams moved to the sediment surface, aiding their passive transport to areas with more favourable conditions. The clams showed a high sulphide detoxification capacity by oxidizing the penetrating hydrogen sulphide to non-toxic thiosulphate. Moreover, juvenile D. serra switched to anaerobic energy production, indicated by the significant accumulation of succinate and, to some extent, alanine. Test animals were not able to reduce their energy requirements enough to withstand long periods of exposure, leading to a median survival time (LT 50) of 80 h under hypoxic sulphide incubation. In conclusion, natural "sulphide eruptions", especially those with a large spatial and temporal extension, have to be considered as an important factor for D. serra recruitment failures. Hydrogen sulphide is assumed to be a potential community structuring factor. |
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