Temperature of the water in a Jonkershoek pond
Temperature is pivotal to the functioning physiology of ectotherms, and for the principally aquatic frog Xenopus laevis the water temperature dictates the temperature of the animals throughout the year. We know that most of the invasive populations of X. laevis were sourced from the South African Cape region in general, and the Jonkershoek hatcheries near Stellenbosch in particular (van Sittert & Measey 2016).
For the past year, I have had a temperature logger recording the water temperature just above the bottom in a pond in Jonkershoek.
The same pond has been the source of Xenopus laevis for numerous studies, and likely contains animals that are closely related to those shipped from South Africa all over the world.
The temperatures between November 2023 and 2024 show that the water reaches maximum temperatures in early February (27.32 C), and a low 6 months later in early August (7.98 C). Despite these extremes, the water temperature varied only 15 C between 10 and 25 C. This is relatively little change compared to the same loggers deployed in Kwa-Zulu Natal (see here).
Thanks to Martine Jordaan and Andrew Turner who helped with the deployment and collection of this logger.
