Temperature effect on the macroalgae consumption and respiration rate of the invasive crab Percnon gibbesi in the Mediterranean Sea

Abstract

[eng] The Mediterranean Sea is the most invaded marine region in the world. The rise in sea temperatures occurring in this region in the past decades may be exacerbating the ecological impact of exotic species from warmer regions. The invasion of the crab P. gibbesi presents a unique opportunity to study how temperature influences the ecological impact of marine exotic herbivores. This study examines the relationship between temperature and the physiological performance of Percnon gibbesi, particularly focusing on how it affects the herbivory rate on the macroalgae Haliptilon virgatum and the metabolic respiration rate of the crab. The findings highlight that P. gibbesi exhibits an optimal thermal range for algae consumption and respiration between 26.3°C and 31.1°C, with average optimal values per crab of 2.706 g WW macroalgae d-1 crab−1 and 0.915 mg O2 h −1 crab−1, respectively. A theoretical upper thermal limit of P. gibbesi was calculated at 35.39°C. Temperatures within 50% of optimal consumption rates (23.21 – 30.05°C) were considered peak performance, likely occurring during the months of June and November in the shallow rocky subtidal shores in the island of Mallorca. The results underline the potential ecological threat posed by P. gibbesi in the context of global climate change, emphasizing the need for effective management strategies to mitigate its impact on native ecosystems.