Seasonal metabolic and oxidative stress responses of commercially important invertebrate species — Correlation with their habitat

Habitat conditions play a crucial role in food acquisition and the energetic and physiological performance of marine organisms during seasonal changes. However, across a wide distribution, populations of the same species might face physiological constraints driven by the oceanographic and climatological characteristics of their habitats. In the context of climate change, biochemical and metabolic data may be important in identifying marine areas in which inhabiting organisms are more or less physiologically constrained. As a first step in identifying such marine areas on the Greek coast, we studied the seasonal metabolic and antioxidant responses of blue crab Callinectes sapidus, cuttlefish Sepia officinalis, sea cucumber Holothuria tubulosa and clam Venus verrucosa, collected from 3 different Greek gulfs: Thermaikos, Pagasitikos and Vistonikos. Seasonal analysis of metabolic responses was based on the activity of the following intermediary metabolic enzymes: lactate dehydrogenase (L-LDH), octopine dehydrogenase (ODH), β-hydroxyacylCoA dehydrogenase (HOAD) and citrate synthase (CS). Antioxidant responses were based on the activities of the following enzymes: superoxide dismutase (SOD), glutathione reductase (GR) and catalase, and on lipid peroxidation estimation. The blue crab and clam exhibited the most significant seasonal changes compared to the sea cucumber and cuttlefish, which exhibited no changes. The intermediary metabolism enzymatic activity of blue crab and clam decreased and antioxidant enzymatic activity increased during summer. Higher activity levels for all examined species were observed in Pagasitikos and lower levels in Vistonikos Gulf, indicating corresponding oxidative stress. These results are correlated with the spatial oceanographic conditions of the habitats and are discussed based on future projections of global warming in the Mediterranean Sea. © Inter-Research 2021 · www.int-res.co

Seasonal cellular stress responses of commercially important invertebrates at different habitats of the North Aegean Sea

In many aquatic species, the negative effect of temperature variations has a significant impact on physiological performance since beyond Tp (upper pejus) and Tc (critical temperatures), according to the oxygen- and capacity-limited thermal tolerance (OCLTT), transition to hypoxemia and mitochondrial metabolism triggers the increase in reactive oxygen species (ROS) production. However, climate change may have different spatial impact, and as a result, areas with more favorable climatic conditions (refugia) can be identified. The aim of the present study, based on cellular stress responses, is the demarcation of these areas and the preservation of commercially important marine species. Under this prism, individuals of the species Callinectes sapidus (blue crab), Sepia officinalis (common cuttlefish), Holothuria tubulosa (sea cucumber) and Venus verrucosa (clam) from Thermaikos, Pagasitikos and Vistonikos gulf were collected seasonally. The results showed an increase in the levels of several stress indicators exhibiting the triggering of Heat Shock Response, MAPK activation, apoptotic phenomena and increased ubiquitilination during the summer sampling in relation to the spring and autumn samplings concerning blue crab and clam, while no changes were observed for common cuttlefish and sea cucumber. It seems that these cellular responses consist a cytoprotective mechanism against environmental thermal stress. Regarding collection sites, for all examined species, higher cellular stress levels were observed in Pagasitikos, and lower in Vistonikos gulf. This analysis of biochemical and molecular markers is expected to provide a clearer picture for the definition of “refugia” for the above species. © 2020 Elsevier Inc

Seasonal metabolic and oxidative stress responses of commercially important invertebrate species — Correlation with their habitat

Habitat conditions play a crucial role in food acquisition and the energetic and physiological performance of marine organisms during seasonal changes. However, across a wide distribution, populations of the same species might face physiological constraints driven by the oceanographic and climatological characteristics of their habitats. In the context of climate change, biochemical and metabolic data may be important in identifying marine areas in which inhabiting organisms are more or less physiologically constrained. As a first step in identifying such marine areas on the Greek coast, we studied the seasonal metabolic and antioxidant responses of blue crab Callinectes sapidus, cuttlefish Sepia officinalis, sea cucumber Holothuria tubulosa and clam Venus verrucosa, collected from 3 different Greek gulfs: Thermaikos, Pagasitikos and Vistonikos. Seasonal analysis of metabolic responses was based on the activity of the following intermediary metabolic enzymes: lactate dehydrogenase (L-LDH), octopine dehydrogenase (ODH), β-hydroxyacylCoA dehydrogenase (HOAD) and citrate synthase (CS). Antioxidant responses were based on the activities of the following enzymes: superoxide dismutase (SOD), glutathione reductase (GR) and catalase, and on lipid peroxidation estimation. The blue crab and clam exhibited the most significant seasonal changes compared to the sea cucumber and cuttlefish, which exhibited no changes. The intermediary metabolism enzymatic activity of blue crab and clam decreased and antioxidant enzymatic activity increased during summer. Higher activity levels for all examined species were observed in Pagasitikos and lower levels in Vistonikos Gulf, indicating corresponding oxidative stress. These results are correlated with the spatial oceanographic conditions of the habitats and are discussed based on future projections of global warming in the Mediterranean Sea. © Inter-Research 2021 · www.int-res.co

Seasonal cellular stress responses of commercially important invertebrates at different habitats of the North Aegean Sea

In many aquatic species, the negative effect of temperature variations has a significant impact on physiological performance since beyond Tp (upper pejus) and Tc (critical temperatures), according to the oxygen- and capacity-limited thermal tolerance (OCLTT), transition to hypoxemia and mitochondrial metabolism triggers the increase in reactive oxygen species (ROS) production. However, climate change may have different spatial impact, and as a result, areas with more favorable climatic conditions (refugia) can be identified. The aim of the present study, based on cellular stress responses, is the demarcation of these areas and the preservation of commercially important marine species. Under this prism, individuals of the species Callinectes sapidus (blue crab), Sepia officinalis (common cuttlefish), Holothuria tubulosa (sea cucumber) and Venus verrucosa (clam) from Thermaikos, Pagasitikos and Vistonikos gulf were collected seasonally. The results showed an increase in the levels of several stress indicators exhibiting the triggering of Heat Shock Response, MAPK activation, apoptotic phenomena and increased ubiquitilination during the summer sampling in relation to the spring and autumn samplings concerning blue crab and clam, while no changes were observed for common cuttlefish and sea cucumber. It seems that these cellular responses consist a cytoprotective mechanism against environmental thermal stress. Regarding collection sites, for all examined species, higher cellular stress levels were observed in Pagasitikos, and lower in Vistonikos gulf. This analysis of biochemical and molecular markers is expected to provide a clearer picture for the definition of “refugia” for the above species. © 2020 Elsevier Inc