Effects of dietborne cadmium on life history and secondary production of a tropical freshwater cladoceran

Autor(es)

Souza, J. P. ^[1] ; Melo, D. C. ^[1] ; Lombardi, A. T. ^[2] ; Melao, M. G. G. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Hydrobiol Dept, Plankton Lab, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Algae Biotechnol Lab, Dept Bot, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ECOTOXICOLOGY; v. 23, n. 9, p. 1764-1773, NOV 2014.
• Citações Web of Science: 4

Resumo

The presence of metals in aquatic environments has increased worldwide. Environmental assessments of metals in freshwater ecosystems presume that toxicity is mainly caused by aqueous exposure, but dietborne exposure (contaminated food) in zooplankton may occur because microalgae carry metal ions through adsorption/absorption of dissolved metal species, resulting in toxic effects once ingested by the animals. However, official regulations for ecotoxicological assays in most countries do not consider the toxic effects caused by dietborne exposure. Here, we provide life history parameters and secondary production of Simocephalus serrulatus (Koch 1841) (Cladocera: Daphniidae) fed with cadmium (Cd) contaminated algae during a 21-day bioassay. The microalgae Chlorophyceae Scenedesmus quadricauda was exposed for 96 h to dissolved Cd concentrations of 0.03; 5.87; 12.27 and 22.27 A mu g Cd l(-1) (equivalent to 1.6 x 10(-10); 3.2 x 10(-8); 6.7 x 10(-8); 1.2 x 10(-7) mol l(-1)) that resulted in algae internal Cd burdens of 0.004; 0.032; 0.270 and 0.280 pg Cd cell(-1), respectively. Significant toxic effects on life history parameters of S. serrulatus were observed. Time of embryonic development, generation time and age at first reproduction (primipara) showed significant delay. Length at first reproduction, number of eggs and clutches produced per female, hatching percentage, body length, survival and feeding rates were significantly reduced. Secondary production, that is, accumulated biomass for growth and reproduction, decreased significantly with dietborne Cd concentrations. Our results emphasize that food can be an important source of metals to zooplankton in aquatic ecosystems. Environmental regulations should consider the diet in ecotoxicological assessments. Furthermore, secondary production may be considered as a suitable endpoint in ecotoxicity tests. (AU)

• Processo FAPESP: 08/05464-7 - Toxicidade, bioacumulação e padrões de recuperação em uma cadeia alimentar experimental aquática exposta a alimento contaminado com metal pesado.
• Beneficiário: Jaqueline Pérola de Souza
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 08/02078-9 - Estudos ecofisiológicos e de processos produtivos do Anostraca dulcícola Dendrocephalus brasiliensis Pesta 1921 e suas implicações nas comunidades zooplanctônica e nectônica
• Beneficiário: Maria da Graça Gama Melão
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 08/03487-0 - Cultivo de microalgas em fotobiorreator como ferramenta para o sequestro do CO2 atmosférico
• Beneficiário: Ana Teresa Lombardi
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - PITE