Elasmobranchs possess a unique system for osmoregulation. They are slightly hyperosmotic compared to their environment due to high levels of urea and trimethylamino oxide in their body.
metal exposure
Genetic characterisation of several tidal organisms along a pollution gradient in the Scheldt estuary
The genetic population structure of natural populations of the indirect developing (i.e. planctonic development) periwinkle, Littorina littorea and of the direct developer (i.e. non-planctonic development) L.
An integrated study of the relationship between exposure and accumulation of metals by the wood mouse (Apodemus sylvaticus)
Over the years, our environment became polluted by various hazardous substances, such as heavy metals. Contamination by heavy metals may have severe effects on every level of biological organisation, i.e. from cell to ecosystem. An important problem that frequently occurs in ecotoxicological metal studies is that a clear relationship between exposure, accumulation and effects of heavy metals in an organism is often not found under natural conditions. There are two possible explanations. First, in many papers the absolute concentration of heavy metals in the soil and in the food are quantified while a large fraction of these metals are not bioavailable for the organism. Second, acclimatisation and/or adaptation to heavy metal contamination can result in a reduced uptake and accumulation of the bioavailable fraction of heavy metals and an altered sensitivity or tolerance. However, it is still unclear how and to what extent organisms can adapt and/or acclimatise to heavy metal contamination. Possible ways are: (1) a reduced absorption of heavy metals, (2) an increased excretion of heavy metals, (3) a different organ and tissue distribution and (3) a more efficient induction of detoxifying mechanisms like metallothionein (MT).
Characterisation and dynamics of metal toxicity in carp by means of gene expression profiling
Although cadmium toxicity is a well studied theme in the field of aquatic toxicology, still little is known concerning the molecular mechanisms of its toxic action. Moreover most laboratory studies only consider waterborne cadmium exposure, whereas dietary exposure can also contribute to the accumulation and effects of cadmium in fish. For a better understanding of the toxic responses leading to adverse effects there is an increasing need for more sensitive tools to determine early reactions on cadmium exposure and accumulation.
