Heart rate responses to different temperatures in juvenile Poppiana dentata ( )

Abstract Temperature is one of the main factors that influences cardiovascular functioning in ectotherms. Hence this study sought to investigate heart rate responses of a freshwater crab species, Poppiana dentata, to different temperature exposures since the species generally reside in habitats of fluctuating physicochemistry. Heart rates were non-invasively determined in juvenile crabs for three temperature regimes, each over an 8-day session; A: temperature exposures of 26 °C (2 days) to 30 °C (3 days) to 26 °C (3 days), B: 26 °C (2 days) to 32 °C (3 days) to 26 °C (3 days) and C: a control at constant 26 °C. Heart rate variations were significant among the regimes (P