Prediction of acute fish toxicity:

The use of zebrafish (Danio rerio) embryos for the prediction of fish acute toxicity is a valuable and increasingly accepted alternative to animal test with juvenile or adult fish. Up to 5 days after fertilization, respectively until the onset of independent feeding, fish embryos do not fall under animal welfare regulation, with the assumption that embryos do not suffer pain because the nervous system is still in development. Yet it holds the complexity of an organism as a whole.

Numerous studies have demonstrated the excellent comparability of lethal concentrations (LC50s) obtained with zebrafish embryos compared to lethal concentrations determined in the conventional fish acute toxicity test (OECD 203). Zebrafish embryos have replaced tests with fish for effluent testing in Germany since 2005 according to ISO 15088; in July 2013, the OECD guideline 236 for testing of chemicals using the zebrafish embryo was adopted.

In the zebrafish embryo toxicity test according to OECD 236, the freshly fertilized embryos are exposed to the test item in 5 concentrations over a course of 96 hours. Every 24 hours, four apical parameters of acute toxicity are recorded and the lethal concentration (LC50) is calculated based on the 96 hours observation.

In addition to this standardized test, we offer flexible test designs according to your needs, e.g. extension of the test duration up to 120 hours and recording of sub-lethal effect parameters. We moreover hold strong expertise in the establishment of optimal test designs for the assessment of difficult to test chemicals, e.g. with respect to chemical stability.

For further information concerning the Zebrafish Embryo Test, see fact sheet Zebrafish Embryo Toxicity Tests.

Determination of other parameters:

The development of a fish embryo is a complex process. Exposure to chemicals or environmental samples does not necessarily cause macroscopically detectable lethal or sub-lethal effects. Such effects may, however, take shape on the molecular level and impact fish health later on.

Such effects can be recorded on the level of the expression of genes. Accordingly, we offer a wide variety of molecular biomarkers, which reflect a wide spectrum of cellular responses, such as endocrine disruption, general stress response, biotransformation and immune regulation.

Additionally, we offer diverse behavioral tests with zebrafish embryos up to 120 hours in order to capture neurotoxic reactions of the fish upon exposure to chemicals or environmental samples.