Dataset on temperature dependency of zebrafish early development.

Zebrafish (Danio rerio) early development stages that do not feed independently, are classified as non-protected life stages under EU Directive 2010/63. Zebrafish reach the independently feeding stage not earlier than 120 hours post fertilization, depending on the incubation temperature. This paper presents a dataset documenting zebrafish early development at two commonly used temperatures 26 °C and 28 °C. We recorded onset of heartbeat and hatching as well as body length, eye size, yolk sac consumption, and swim bladder inflation. Additionally, locomotor activity was tracked after 96 and 119 hours post fertilization. The dataset offers a reference for selecting appropriate experimental conditions and optimizing toxicological study designs. They also facilitate the comparison of experimental results recorded at these two temperatures. Furthermore, the data provide empirical evidence for amending current guidelines for tests with zebrafish embryos, in particular moving away from a rigid 120 hours post fertilization maximum test duration towards a temperature-dependent maximum test duration that is still in line with the aims of the German Animal Welfare Act.