method development

Measuring swimming performance of small fishes contributes to a better understanding of how environmental factors affect individual organisms and potentially populations dynamics (e.g., through variable dispersal and connectivity). Here, we automated multi-lane swimming chambers to reduce operator interference and optimize swimming performance measurements of early life stages of fishes. Testing different experimental protocols, we found species-specific sensitivities in offspring from two tropical fishes.

In this study, we showed that critical thermal maxima differ across species and life stages in tropical fishes. Furthermore, body mass and experimental heating rate had a strong influence on the measured thermal tolerance. This suggests that these factors need to be accounted for when estimating and comparing heat tolerance across early ontogeny in tropical fishes.