Effects of a saxitoxin-producer strain ofCylindrospermopsis raciborskii (cyanobacteria) on the swimming movements of cladocerans
| Autor: | Manuel Gustavo Leitão Ribeiro, Sandra M.F.O. Azevedo, Simone M. Costa, Aloysio da Silva Ferrão Filho |
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| Rok vydání: | 2008 |
| Předmět: |
Cyanobacteria
Movement Health Toxicology and Mutagenesis Zoology Branchiopoda Management Monitoring Policy and Law Toxicology Daphnia Cylindrospermopsis raciborskii chemistry.chemical_compound Toxicity Tests Acute Animals Ecotoxicology Swimming Saxitoxin Dose-Response Relationship Drug biology General Medicine Cladocera biology.organism_classification Pulex chemistry Cylindrospermopsis |
| Zdroj: | Environmental Toxicology. 23:161-168 |
| ISSN: | 1522-7278 1520-4081 |
| Popis: | This study evaluated the effects of a saxitoxin-producer strain (T3) of the cyanobacteria species Cylindrospermopsis raciborskii on the swimming movements of three cladoceran species (Daphnia gessneri, D. pulex, and Moina micrura). Acute toxicity bioassays were designed to access the effects of T3 strain, of a nonsaxitoxin producer strain (NPLP-1) of the same species and of a raw water sample from Funil reservoir (Rio de Janeiro, Brazil), that contained this and other cyanobacteria. In the acute bioassays, animals were exposed to C. raciborskii filaments or Funil water for 24-48 h and then transferred to food suspensions without cyanobacterial filaments for a further 48 h. During the exposure time to T3 strain filaments there was a decrease in the number of swimming individuals, with animals showing progressive immobilization. The same effect was observed with Funil water sample. Animals stayed alive on the bottom of the test tube and recovered swimming movements when transferred to food suspensions without toxic cells. This effect was not observed with the strain NPLP-1. The cladoceran D. pulex showed to be extremely sensitive to T3 strain and to Funil water containing C. raciborskii filaments, showing complete paralysis after 24-h exposure to T3 cell densities of 10(3) and 10(4) cells mL(-1), and after 24-h exposure to only 10% of raw water. However, D. gessneri was not sensitive to both T3 and to Funil water, whereas M. micrura was intermediate in sensitivity. This is the first report on the effects of cyanobacterial saxitoxins on movements of freshwater cladocerans, showing also difference in sensitivity among closely related Daphnia species. |
| Databáze: | OpenAIRE |
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