Hormesis-stimulation of colony growth in Campanularia flexuosa (hydrozoa) by copper, cadmium and other toxicants
In: Aquatic Toxicology. Elsevier Science: Tokyo; New York; London; Amsterdam. ISSN 0166-445X; e-ISSN 1879-1514, more
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| Keywords |
Chemical elements > Metals
Chemical elements > Metals > Heavy metals > Cadmium
Chemical elements > Metals > Transition elements > Heavy metals > Copper
Hormesis
Population functions > Growth
Hydroida [WoRMS]
Marine/Coastal |
| Abstract |
It is shown experimentally that subinhibitory concentrations of a number of toxic, or other agents that are typically inhibitory (copper, cadmium, tributyl tin fluoride, reduced salinity), may stimulate the growth of colonies of the hydroid Campanularia flexuosa, exhibiting a phenomenon known as hormesis. It is suggested that the stimulation of growth is not due to the specific properties of the different toxicants, but to an adaptive response of the hydroid to the inhibitory effect that they have in common. Growth is regulated by a control mechanism and it is proposed that the increased growth is a consequence of overcorrections to low levels of an inhibitory challenge. Examination of the toxicological literature shows that hormesis is a more common occurrence that is generally supposed, and it is suggested that the explanation given here might apply in other cases of hormesis. |
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