Rock Sebastian, Rodenburg Frans, Schaaf Marcel J M, Tudorache Christian
Institute of Biology, Leiden University, Leiden, Netherlands.
Front Physiol. 2022 Apr 11;13:827282. doi: 10.3389/fphys.2022.827282. eCollection 2022.
Research on stress coping style, i.e., the response of an organism to adverse conditions, which is constant over time and context, gained momentum in recent years, to better understand behavioural patterns in animal welfare. However, knowledge about the ontogeny of stress coping style is still limited. Here, we performed a detailed analysis of the light dark challenge behavioural assay in zebrafish larvae, where after acclimation in ambient light sudden alternating dark and light phases elicit an anxiety-like response. A principal component analysis on parameters related to locomotion (distance moved, swimming velocity, acceleration, mobility) and directionality (angular velocity, meandering of swimming path) revealed independence between the parameters determined in the light and the dark phases of the assay, indicating unrelated generalised behaviours per phase. However, high collinearity was observed between behavioural parameters within the same phase, indicating a robust response to the stimulus within behavioural phenotypes. Subsequently, this assay was used to determine the correlation between individual hatching time and the behavioural phenotype. The results show that fish that had hatched during daytime have a stronger behavioural response to the dark phase at 5 days post-fertilisation in locomotion related parameters and a weaker response in directionality related parameters, than fish that had hatched during nighttime. These results show that behavioural responses to the light dark challenge assay are robust and can be generalised for the light and the dark phase, and that diel hatching time may determine the behavioural phenotype of an individual.
对应激应对方式的研究，即生物体对不利条件的反应，这种反应在时间和环境上是恒定的，近年来得到了进一步发展，以便更好地理解动物福利中的行为模式。然而，关于应激应对方式个体发生的知识仍然有限。在此，我们对斑马鱼幼体的明暗挑战行为试验进行了详细分析，在该试验中，幼体在环境光下适应后，突然交替的黑暗和光明阶段会引发类似焦虑的反应。对与运动（移动距离、游泳速度、加速度、活动能力）和方向性（角速度、游泳路径曲折度）相关的参数进行主成分分析，结果显示试验的明相和暗相中所测定的参数相互独立，这表明每个阶段的一般行为是不相关的。然而，在同一阶段内的行为参数之间观察到高度共线性，这表明在行为表型内对刺激有强烈反应。随后，该试验被用于确定个体孵化时间与行为表型之间的相关性。结果表明，与夜间孵化的鱼相比，白天孵化的鱼在受精后5天对暗相的运动相关参数有更强的行为反应，而在方向性相关参数方面反应较弱。这些结果表明，对明暗挑战试验的行为反应是强烈的，并且可以推广到明相和暗相，而且昼夜孵化时间可能决定个体的行为表型。
