Journal article
Dangerous relations in the Arctic marine food web: Interactions between toxin producing Pseudo-nitzschia diatoms and Calanus copepodites
University of Copenhagen1
National Institute of Aquatic Resources, Technical University of Denmark2
Section for Marine Ecology and Oceanography, National Institute of Aquatic Resources, Technical University of Denmark3
Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research4
Aarhus University5
Diatoms of the genus Pseudo-nitzschia produce domoic acid (DA), a toxin that is vectored in the marine food web, thus causing serious problems for marine organisms and humans. In spite of this, knowledge of interactions between grazing zooplankton and diatoms is restricted. In this study, we examined the interactions between Calanus copepodites and toxin producing Pseudo-nitzschia.
The copepodites were fed with different concentrations of toxic P. seriata and a strain of P. obtusa that previously was tested to be non-toxic. The ingestion rates did not differ among the diets (P. seriata, P. obtusa, a mixture of both species), and they accumulated 6%–16% of ingested DA (up to 420 μg per dry weight copepodite).
When P. seriata was exposed to the copepodites, either through physical contact with the grazers or separated by a membrane, the toxicity of P. seriata increased (up to 3300%) suggesting the response to be chemically mediated. The induced response was also triggered when copepodites grazed on another diatom, supporting the hypothesis that the cues originate from the copepodite.
Neither pH nor nutrient concentrations explained the induced DA production. Unexpectedly, P. obtusa also produced DA when exposed to grazing copepodites, thus representing the second reported toxic polar diatom
Language: | English |
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Publisher: | MDPI |
Year: | 2015 |
Pages: | 3809-3835 |
ISSN: | 16603397 |
Types: | Journal article |
DOI: | 10.3390/md13063809 |
ORCIDs: | 0000-0001-6213-6657 , 0000-0002-4327-6387 , 0000-0002-2035-1997 , Nielsen, Torkel Gissel and 0000-0002-7640-3514 |