Red porgy?s (Pagrus pagrus) cellular physiology and antioxidant defense in response to seasonality

Physiological stress patterns of marine organisms in their natural habitats are considerably complex in space and time. These patterns can eventually contribute in the shaping of fish' thermal limits under natural conditions. In the view of the knowledge gap regarding red porgy's thermal physiology, in combination with the character-ization of the Mediterranean Sea as a climate change hotspot, the aim of the present study was to investigate this species biochemical responses to constantly changing field conditions. To achieve this goal, Heat Shock Response (HSR), MAPKs pathway, autophagy, apoptosis, lipid peroxidation and antioxidant defense were esti-mated and exhibited a seasonal pattern. In general, all the examined biochemical indicators expressed high levels parallel to the increasing seawater temperature in spring, although several bio-indicators have shown increased levels when fish were cold-acclimatized. Similar to other sparids, the observed patterns of physiological re-sponses in red porgy may support the concept of eurythermy.

Automated summary

Physiological stress patterns of marine organisms play a crucial role in determining the thermal limits of fish in their natural habitats. This study aims to investigate the biochemical responses of red porgy to constantly changing field conditions, bridging the knowledge gap in its thermal physiology and considering the Mediterranean Sea as a climate change hotspot. Various biochemical indicators, including Heat Shock Response, MAPKs pathway, autophagy, apoptosis, lipid peroxidation, and antioxidant defense, exhibited a seasonal pattern, with higher levels correlated with increasing seawater temperature in spring. The observed physiological responses in red porgy suggest its ability to adapt to a wide range of temperatures, supporting the concept of eurythermy.