Toxic and inhibitory effects of the blue-green alga Microcystis aeruginosa on herbivorous zooplankton
Blooms of blue-green algae are often associated with declines in populations of large-bodied cladocerans and increased importance of small cladocerans, copepods, and rotifers. We conducted toxicity and herbivory experiments, using a wide range of herbivore taxa, to test the hypothesis that the blue-...
| Published in: | Journal of Plankton Research |
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| Main Authors: | , |
| Format: | Text |
| Language: | English |
| Published: |
Oxford University Press
1987
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| Subjects: | |
| Online Access: | http://plankt.oxfordjournals.org/cgi/content/short/9/5/837 https://doi.org/10.1093/plankt/9.5.837 |
| Summary: | Blooms of blue-green algae are often associated with declines in populations of large-bodied cladocerans and increased importance of small cladocerans, copepods, and rotifers. We conducted toxicity and herbivory experiments, using a wide range of herbivore taxa, to test the hypothesis that the blue-green alga Microcystis aeruginosa most strongly inhibits large cladocerans. For a variety of herbivore taxa, M. aeruginosa was toxic or non-nutritious, and inhibited feeding on co-occurring nutritious food. The rotifer Brachionus calyciflorus was unique in several respects: it was unaffected by M. aeruginosa toxins, it showed some ability to grow and reproduce on a diet of M. aeruginosa , and it maintained high feeding rates on co-occurring nutritious food in the presence of bloom densities of M. aeruginosa . There was a strong relation between the toxicity of M. aeruginosa and its inhibitory effect on herbivore feeding rates. Copepods strongly avoided consuming M. aeruginosa , but all cladocerans and rotifers tested filtered unicellular M. aeruginosa at rates similar to or higher than nutritious Chlamydomonas reinhardi . Our results indicate that there are a variety of mechanisms whereby herbivorous zooplankton can coexist with blooms of M. aeruginosa , including resistance to toxic chemicals ( B. calyciflorus ), and avoidance of consumption of M. aeruginosa by chemosensory means (copepods), or by the inability to consume large colonies (some small cladocerans). |
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