Investigating the effects of hypersalinity on the cardiac performance of the invasive gastropod Melanoides tuberculata (Müller, 1774)

Abstract

Anthropogenic activities have propelled the exploitation of natural environments, which along with climate change have resulted in salinity intrusion to freshwater ecosystems worldwide. To determine the extent the hypersalinity stressor has on freshwater ecosystems, physiological cardiac responses in the freshwater gastropod Melanoides tuberculata were analysed during an acute exposure to varying salinity concentrations. A non-invasive method was used to monitor the cardiac activity of the organisms. The mean heart rate (bpm) of M. tuberculata declined significantly between 20 ppt and 30 ppt. Melanoides tuberculata exhibited a hypersalinity threshold of 25 ppt and tolerated salinity concentrations up to 50 ppt. Data collected provide background data for the use of M. tuberculata as a bioindicator organism to assess the effects of hypersalinity on cardiac response of organisms in a freshwater ecosystem.