Smithers has performed multiple Medaka Extended One Generation Reproduction Tests (MEOGRTs) for clients in recent years. These complex studies require meticulous planning and organization, as well as the most experienced ecotoxicologists to ensure satisfactory performance over multiple endpoints.
Tracey Goodband, Senior Manager, Aquatic Ecotoxicology
in Harrogate, and her team focused on improving reliability of the more challenging control validity criteria of the MEOGRT - fecundity for the first (F0
) and second (F1
) generations and hatching success of the F1
generations. By establishing breeding pairs prior to fin clipping for PCR for the F0
generations enables an early assessment of fecundity, and reduces the number of fish subjected to clipping. The team also evaluated using a slightly modified egg chamber design to reduce study contamination.
Another beneficial modification was to shift the day-night cycle of the laboratory lighting to make the “dawn” align with the start of the working day. This means that the eggs can be collected as produced, reducing the risk of eggs being dropped and consumed. This adaptation has beneficial welfare considerations as it reduces the handling, and therefore the stress, of the fish.
Smithers has focused on reducing risk of not meeting control validity criteria, as well as enhancing animal welfare in the MEOGRT. These adaptations help to ensure the first-time successful conduct of the study, with data that can be relied on for global regulatory submissions.
For more information, download the SETAC Europe poster or contact Tracey