Validation of a two-generational reproduction test in Daphnia magna: An interlaboratory exercise

Abstract

Effects observed within one generation disregard potential detrimental effects that may appear across generations. Previously we have developed a two generation Daphnia magna reproduction test using the OECD TG 211 protocol with a few amendments, including initiating the second generation with third brood neonates produced from first generation individuals. Here we showed the results of an inter-laboratory calibration exercise among 12 partners that aimed to test the robustness and consistency of a two generation Daphnia magna reproduction test. Pyperonyl butoxide (PBO) was used as a test compound. Following experiments, PBO residues were determined by TQD-LC/MS/MS. Chemical analysis denoted minor deviations of measured PBO concentrations in freshly prepared and old test solutions and between real and nominal concentrations in all labs. Other test conditions (water, food, D. magna clone, type of test vessel) varied across partners as allowed in the OECD test guidelines. Cumulative fecundity and intrinsic population growth rates (r) were used to estimate “No observed effect concentrations “NOEC using the solvent control as the control treatment. EC10 and EC-50 values were obtained regression analyses. Eleven of the twelve labs succeeded in meeting the OECD criteria of producing >60 offspring per female in control treatments during 21 days in each of the two consecutive generations. Analysis of variance partitioning of cumulative fecundity indicated a relatively good performance of most labs with most of the variance accounted for by PBO (56.4%) and PBO by interlaboratory interactions (20.2%), with multigenerational effects within and across PBO concentrations explaining about 6% of the variance. EC50 values for reproduction and population growth rates were on average 16.6 and 20.8% lower among second generation individuals, respectively. In summary these results suggest that the proposed assay is reproducible but cumulative toxicity in the second generation cannot reliably be detected with this assay.

Assessment of long term ecotoxicity of urban stormwaters using a multigenerational bioassay on Ceriodaphnia dubia: A preliminary study

“…[3,4,5] Endocrine disrupting activities can lead to adverse effects on exposed organisms, but also on their progeny, creating adverse effects on subsequent generations. [6,7] Nowadays, there is undoubtedly an important concern about the long term ecotoxicity assessment of single chemicals and of multi-contaminated matrixes and the scientific community is actively working to create harmonization (OECD guidelines) of multigenerational bioassays on cladocerans (D. magna)…”

“…to detect long-term impairments, as done recently by Barata et al [6] Multigenerational (3 to 5 generations) reproduction inhibition tests have already been developed on C. dubia. Rose et al [8,9] used such an approach for testing the long-term reproduction toxicity of low concentration of 3,4-dichloroaniline (3,4 DCA), a by-product of the herbicide diuron.…”

Avaliação ecogenotoxicológica de corante natural extraído de micro-organismo

“…Diversos estudos ecotoxicológicos realizados em daphnídeos aplicam avaliações de imobilidade, reprodução, comportamento e análises fisiológicas (MARTINS et al, 2007;REN et al, 2009;PESTANA et al, 2010;NOSS et al, 2013;OKAMOTO et al, 2014;BARATA et al, 2016). A seguir, apresentaremos brevemente os ensaios selecionados para a realização deste trabalho.…”

“…(BAE et al, 2006;FREEMAN, 2007;LIU et al, 2007;KANHERE et al, 2014;DARSANA et al, 2015). O critério para a determinação da toxicidade aguda é a completa imobilização destes organismos após 24-48 horas de exposição à substância química em estudo (OECD Guideline 202, 2004 Sob condições adversas, as fêmeas podem responder com a produção de ovos de resistência, alterações no tempo de maturação reprodutiva e no número e tamanho de descendentes (COORS et al, 2004;PESTANA et al, 2010;FURUHAGEN et al, 2014;STANLEY et al, 2016;TRAUDT et al, 2016;BARATA et al, 2016). Do ponto de vista ecológico, alterações na reprodução podem acarretar em uma redução na taxa intrínseca de crescimento populacional dos organismos, a qual compromete a manutenção da população e eleva os riscos de extinções das populações locais (PESTANA et al, 2010).…”

“…Condições ambientais desfavoráveis podem causar um declínio nos custos metabólicos de daphnídeos, analisados pela quantificação da taxa respiratória dos organismos (MICHELS et al, 2000;MARTINS et al, 2007;REN et al, 2009;BAHRNDORFF et al, 2015;HANSEN;ROSLEV, 2016;HÄDER;ERZINGER, 2017). Estas alterações no consumo de oxigênio são associadas a alterações na alocação energética que causam prejuízo a outras funções fisiológicas, como crescimento, reprodução e desenvolvimento (CHOPELET et al, 2008;PESTANA et al, 2010;PESTANA et al, 2013;BARATA et al, 2016).…”