protocol-for-acute-chronic-ecotoxicity-testing-turquoise-killifish

Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish <em>Nothobranchius furzeri</em>

The killifish Nothobranchius furzeri is an emerging model organism in the field of ecotoxicology and its applicability in acute and chronic ecotoxicity ...

University of Leuven

university of the free state

Nothobranchius furzeri is a promising model for ecotoxicological research due to the species' short life cycle and the production of drought-resistant eggs. Although the species is an emerging vertebrate fish model for several fundamental as well as applied research domains, its potential for ecotoxicological research has not yet been tested. The aim of this study was to characterise the acute and chronic sensitivity of this species to copper as compared to other model organisms. Effects of both acute and chronic copper exposure were tested on survival, life history and physiological traits. We report a 24h-LC of 53.93µg Cu/L, which is situated within the sensitivity range of other model species such as Brook Trout, Fathead Minnow and Rainbow Trout. Moreover, in the full life cycle exposure, we show that an exposure concentration of 10.27µg/L did not cause acute adverse effects (96h), but did cause mortality after prolonged exposure (3-4 weeks). Also chronic, sublethal effects were observed, such as a reduction in growth rate, delayed maturation and postponed reproduction. Based on our results, we define the NOEC at 6.68µg Cu/L, making N. furzeri more sensitive to copper as compared to Brook Trout and Fathead Minnow. We found stimulatory effects on peak fecundity at subinhibitory levels of copper concentrations (hormesis). Finally, we found indications for detoxifying and copper-excreting mechanisms, demonstrating the ability of the fish to cope with this essential metal, even when exposed to stressful amounts. The successful application of current ecotoxicological protocols on N. furzeri and its sensitivity range comparable to that of other model organisms forms the basis to exploit this species in further ecotoxicological practices.

Acute and chronic sensitivity to copper of a promising ecotoxicological model species, the annual killifish Nothobranchius furzeri.

Higher temperatures and increased environmental variability under climate change could jeopardize the persistence of species. Organisms that rely on short windows of rainfall to complete their life-cycles, like desert annual plants or temporary pool animals, may be particularly at risk. Although some could tolerate environmental changes by building-up banks of propagules (seeds or eggs) that buffer against catastrophes, climate change will threaten this resilience mechanism if higher temperatures reduce propagule survival. Using a crustacean model species from temporary waters, we quantified experimentally the survival and dormancy of propagules under anticipated climate change and used these demographic parameters to simulate long term population dynamics.

Climate change jeopardizes the persistence of freshwater zooplankton by reducing both habitat suitability and demographic resilience.

Aquatic organisms of inland waters are often subjected to a combination of stressors. Yet, few experiments assess mixed stress effects beyond a select group of standard model organisms. We studied the joint toxicity of reference toxicants and increased temperature on the turquoise killifish, Nothobranchius furzeri, a promising model for ecotoxicological research due to the species' short life cycle and the production of drought-resistant eggs. The acute sensitivity of the larval stage (2dph) to three compounds (cadmium, 3,4-dichloroaniline and chlorpyrifos) was tested in combination with a temperature increase of 4 °C, mimicking global warming. Dose-response relationships were used to calculate 96h-LC of 0.28 mg/L (24 °C) and 0.39 mg/L (28 °C) for cadmium, 96h-LC of 9.75 mg/L (24 °C) and 6.61 mg/L (28 °C) for 3,4-dichloroaniline and 96h-LC of 15.4 μg/L (24 °C) and 14.2 μg/L (28 °C) for chlorpyrifos. After 24 h of exposure, the toxicity of all tested compounds was exacerbated under increased temperature. Furthermore, the interaction effect of cadmium and temperature could be predicted by the stress addition model (SAM). This suggests the applicability of the model for fish and at the same time indicates that the model could be suitable to predict effects of temperature-toxicant interactions.

Acute sensitivity of the killifish Nothobranchius furzeri to a combination of temperature and reference toxicants (cadmium, chlorpyrifos and 3,4-dichloroaniline).

Tom Pinceel

Animal Ecology,
Global Change and Sustainable Development,
Animal Ecology, Global Change and Sustainable Development

University of Leuven

Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish Nothobranchius furzeri

Tom Pinceel

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Animal Ecology,Global Change and Sustainable Development,Animal Ecology, Global Change and Sustainable Development

University of Leuven

Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish Nothobranchius furzeri

Animal Ecology,
Global Change and Sustainable Development,
Animal Ecology, Global Change and Sustainable Development