Thermal tolerance of Acartia tonsa: In relation to acclimation temperature and life stage

Abstract

The Acartia tonsa, a calanoid copepod species, has high survival and thermal acclimation capacity in aquatic environments characterized by temperature variations. Dynamic and static thermal polygon areas of this species are 495 °C2 and 267 °C2 for nauplii stage, while adult stage has 747 °C2 and 411 °C2 dynamic and static thermal polygon area, respectively. In addition, Acartia tonsa is a copepod species which is more resistant to both high and low lethal temperatures, with its resistance zone of 105 °C2 and 131 °C2 for nauplii and adults, respectively. Acartia tonsa nauplii acclimated to 18 °C, 23 °C and 28 °C have lover and upper thermal limit (CTMin-CTMax) of 6.82–26.15 °C, 8.65–29.49 °C, and 11.70–34.10 °C, respectively. This species in the adult stage has a CTMin-CTMax of 4.47–30.30 °C, 6.35–33.94 °C, and 9.92–35.90 °C at acclimation temperatures mentioned above. Its broad dynamic and static thermal tolerance polygon areas and, accordingly, its significant thermal limits allow Acartia tonsa to survive at warm or cold extremes in their natural environment.