Stygobitic copepods in the face of climate change: insights from Moraria sp. in Corchia Cave

Currently, there is a lack of comprehensive knowledge regarding the life-history traits of stygobitic copepods, the dominant crustacean group inhabiting groundwater ecosystems. Moreover, the responses of stygobitic copepods to climate change are still scarcely investigated. We collected specimens of Moraria sp., a harpacticoid species endemic to the Corchia Cave in the Apuan Alps (Italy). We monitored their development, survival, and reproduction rates in the laboratory for one year, to investigate the life-history traits of this species. In addition, we measured the oxygen consumption rates of adult females in a temperature range from 8°C (i.e., the average annual temperature of the dripping waters of the Corchia Cave) to 12.5°C (i.e., the maximum temperature expected in the next century according to climate change scenarios). Our findings suggest that Moraria sp. is a stenothermal species with remarkable stygobitic traits (long life spans, low metabolic rates). We also found that even a 1.5°C heat increment had a considerable impact on its metabolism. According to our results, this species did not experience any metabolic compensation after two weeks of exposure to temperatures above 8°C. Therefore, Moraria sp. might not be able to withstand the heat fluctuations brought on by climate change.