Two faces of one coin: Beneficial and deleterious effects of reactive oxygen species during short-term acclimation to hypo-osmotic stress in a decapod crab.

Exposure to environmental changes often results in the production of reactive oxygen species (ROS), which, if uncontrolled, leads to loss of cellular homeostasis and oxidative distress. However, at physiological levels these same ROS are known to be key players in cellular signaling and the regulation of key biological activities (oxidative eustress). While ROS are known to mediate salinity tolerance in plants, little is known for the animal kingdom.

REVIEW: Evidence supporting the 'preparation for oxidative stress' (POS) strategy in animals in their natural environment.

Hypometabolism is a common strategy employed by resilient species to withstand environmental stressors that would be life-threatening for other organisms. Under conditions such as hypoxia/anoxia, temperature and salinity stress, or seasonal changes (e.g.

Wastewater sequencing as a powerful tool to reveal SARS-CoV-2 variant introduction and spread in French Guiana, South America.

The origin of introduction of a new pathogen in a country, the evolutionary dynamics of an epidemic within a country, and the role of cross-border areas on pathogen dynamics remain complex to disentangle and are often poorly understood. For instance, cross-border areas represent the ideal location for the sharing of viral variants between countries, with international air travel, land travel and waterways playing an important role in the cross-border spread of infectious diseases. Unfortunately, monitoring the point of entry and the evolutionary dynamics of viruses in space and time within local populations remain challenging.

Salinity stress in the black-chinned tilapia Sarotherodon melanotheron.

Physiological and morphological acclimation capacities of black-chinned tilapia, Sarotherodon melanotheron were studied from fish to gill cell level when fish are maintained in freshwater, seawater, and hypersaline conditions. Fish osmoregulatory capacity, gill ionocyte morphology, osmo-respiratory compromise, O consumption rate, branchial antioxidative defense, and cell apoptosis were considered. Captive juvenile tilapias were maintained in controlled freshwater conditions (FW: 0.

ONTdeCIPHER: an amplicon-based nanopore sequencing pipeline for tracking pathogen variants.

Motivation: Amplicon-based nanopore sequencing is increasingly used for molecular surveillance during epidemics (e.g. ZIKA, EBOLA) or pandemics (e.

Metabolic Cost of the Immune Response During Early Ontogeny of the Scallop .

The scallop is an important resource for Chilean and Peruvian aquaculture. Seed availability from commercial hatcheries is critical due to recurrent massive mortalities associated with bacterial infections, especially during the veliger larval stage. The immune response plays a crucial role in counteracting the effects of such infections, but being energetically costly, it potentially competes with the physiological and morphological changes that occur during early development, which are equally expensive.

Effects of temperature and salinity on antioxidant responses in livers of temperate (Dicentrarchus labrax) and tropical (Chanos Chanos) marine euryhaline fish.

Temperature and salinity are abiotic factors that affect physiological responses in aquaculture species. The European sea bass (Dicentrarchus labrax) is a temperate species that is generally farmed at 18 °C in seawater (SW). In the wild, its incursions in shallow habitats such as lagoons may result in hyperthermal damage despite its high thermal tolerance.

The hepatopancreas of the mangrove crab Neosarmatium africanum: a possible key to understanding the effects of wastewater exposure (Mayotte Island, Indian Ocean).

Mangrove crabs are ecosystem engineers through their bioturbation activity. On Mayotte Island, the abundance of Neosarmatium africanum decreased in wastewater-impacted areas. Previous analyses showed that global crab metabolism is impacted by wastewater, with a burst in O consumption that may be caused by osmo-respiratory trade-offs since gill functioning was impacted.

Environmental stress responses in sympatric congeneric crustaceans: Explaining and predicting the context-dependencies of invader impacts.

The role of ecophysiology in mediating marine biological pollution is poorly known. Here we explore how physiological plasticity to environmental stress can explain and predict the context-dependencies of invasive species impacts. We use the case of two sympatric skeleton shrimps, the invader Caprella scaura and its congener C.

The use of an in vitro approach to assess marine invertebrate carboxylesterase responses to chemicals of environmental concern.

Carboxylesterases (CEs) are key enzymes which catalyse the hydrolysis reactions of multiple xenobiotics and endogenous ester moieties. Given their growing interest in the context of marine pollution and biomonitoring, this study focused on the in vitro sensitivity of marine invertebrate CEs to some pesticides, pharmaceuticals, personal care products and plastic additives to assess their potential interaction on this enzymatic system and its suitability as biomarkers. Three bivalves, one gastropod and two crustaceans were used and CEs were quantified following current protocols set for mammalian models.

Are we neglecting earth while conquering space? Effects of aluminized solid rocket fuel combustion on the physiology of a tropical freshwater invertebrate.

Space launchers often use aluminized-solid fuel ("propergol") as propellant and its combustion releases tons of AlO and HCl that sink in terrestrial and aquatic environments, polluting and decreasing water pH. We studied the impact of these events on the biochemical/physiological performance of the freshwater shrimp Macrobrachium jelskii, with wild specimens collected from a non-impacted site in French Guiana. In the laboratory, shrimps were exposed for one week to: i) undisturbed conditions; ii) AlO exposure (0.

How do life-history traits influence the fate of intertidal and subtidal Mytilus galloprovincialis in a changing climate?

Coastal organisms (i.e. intertidal or upper subtidal species) live in between the terrestrial and aquatic realms, making them particularly vulnerable to climate change.

Biomarker considerations in monitoring petrogenic pollution using the mussel Mytilus galloprovincialis.

Mussels are worldwide bioindicators in pollution monitoring since they fulfil the requirements for being good sentinels. However, some methodological concerns arise in the use of particular biomarkers, particularly those displaying low enzymatic rates and/or limited responsiveness to chemicals and biological-related variability. In the present study, the suitability of oxidative stress and detoxification parameters when using mussels as sentinels of polycyclic aromatic hydrocarbon (PAH) pollution is addressed.

Copper and cadmium administration induce toxicity and oxidative stress in the marine flatworm Macrostomum lignano.

The contamination of coastal regions with different toxicants, including heavy metal ions such as copper and cadmium jeopardize health and survival of organisms exposed to this habitat. To study the effects of high copper and cadmium concentrations in these marine environments, we used the flatworm Macrostomum lignano as a model. This platyhelminth lives in shallow coastal water and is exposed to high concentrations of all toxicants that accumulate in these sea floors.

Wastewater bioremediation by mangrove ecosystems impacts crab ecophysiology: In-situ caging experiment.

Mangroves are tidal wetlands that are often under strong anthropogenic pressures, despite the numerous ecosystem services they provide. Pollution from urban runoffs is one such threats, yet some mangroves are used as a bioremediation tool for wastewater (WW) treatment. This practice can impact mangrove crabs, which are key engineer species of the ecosystem.

Twenty years of the 'Preparation for Oxidative Stress' (POS) theory: Ecophysiological advantages and molecular strategies.

Freezing, dehydration, salinity variations, hypoxia or anoxia are some of the environmental constraints that many organisms must frequently endure. Organisms adapted to these stressors often reduce their metabolic rates to maximize their chances of survival. However, upon recovery of environmental conditions and basal metabolic rates, cells are affected by an oxidative burst that, if uncontrolled, leads to (oxidative) cell damage and eventually death.

Hypoxically Induced Nitric Oxide: Potential Role as a Vasodilator in Gills.

Intertidal experience rapid transgression to hypoxia when they close their valves during low tide. This induces a physiological stress response aiming to stabilize tissue perfusion against declining oxygen partial pressure in shell water. We hypothesized that nitric oxide (NO) accumulation supports blood vessel opening in hypoxia and used live imaging techniques to measure NO and superoxide anion ( ) formation in hypoxia-exposed gill filaments.

Reproduction Immunity Trade-Off in a Mollusk: Hemocyte Energy Metabolism Underlies Cellular and Molecular Immune Responses.

Immune responses, as well as reproduction, are energy-hungry processes, particularly in broadcast spawners such as scallops. Thus, we aimed to explore the potential reproduction-immunity trade-off in , a species with great economic importance for Chile and Peru. Hemocytes, key immunological cells in mollusks, were the center of this study, where we addressed for the first time the relation between reproductive stage, hemocyte metabolic energetics and their capacity to support immune responses at cellular and molecular levels.

Exploring alternative biomarkers of pesticide pollution in clams.

Acetylcholinesterase (AChE) is a reliable biomarker of pesticide exposure although in clams this activity is often very low or undetectable. Carboxylesterases (CEs) exhort several physiological roles, but also respond to pesticides. Searching for an AChE alternative, baseline CE activities were characterised in Ruditapes decussatus gills and digestive glands using five substrates suggestive of different isozymes.

Salinity Variation in a Mangrove Ecosystem: A Physiological Investigation to Assess Potential Consequences of Salinity Disturbances on Mangrove Crabs.

Salinity is one of the main environmental factors determining coastal species distribution. However, in the specific case of mangrove crabs, salinity selection cannot be understood through ecological approaches alone. Yet understanding this issue is crucial in the context of mangrove conservation, since this ecosystem is often used as biofilter of (low- salinity) wastewater.

The use of carboxylesterases as biomarkers of pesticide exposure in bivalves: A methodological approach.

Bivalves are worldwide sentinels of anthropogenic pollution. The inclusion of biomarker responses in chemical monitoring is a recommended practise that has to overcome some difficulties. One of them is the time frame between sample collection and sample processing in order to ensure the preservation of enzymatic activities.

Effects of domestic effluent discharges on mangrove crab physiology: Integrated energetic, osmoregulatory and redox balances of a key engineer species.

Mangroves are increasingly used as biofiltering systems of (pre-treated) domestic effluents. However, these wastewater discharges may affect local macrofauna. This laboratory study investigates the effects of wastewater exposure on the mangrove spider crab Neosarmatium meinerti, a key engineering species which is known to be affected by waste waters in effluent-impacted areas.

Osmoregulation, bioenergetics and oxidative stress in coastal marine invertebrates: raising the questions for future research.

Osmoregulation is by no means an energetically cheap process, and its costs have been extensively quantified in terms of respiration and aerobic metabolism. Common products of mitochondrial activity are reactive oxygen and nitrogen species, which may cause oxidative stress by degrading key cell components, while playing essential roles in cell homeostasis. Given the delicate equilibrium between pro- and antioxidants in fueling acclimation responses, the need for a thorough understanding of the relationship between salinity-induced oxidative stress and osmoregulation arises as an important issue, especially in the context of global changes and anthropogenic impacts on coastal habitats.

Salinity stress from the perspective of the energy-redox axis: Lessons from a marine intertidal flatworm.

In the context of global change, there is an urgent need for researchers in conservation physiology to understand the physiological mechanisms leading to the acquisition of stress acclimation phenotypes. Intertidal organisms continuously cope with drastic changes in their environmental conditions, making them outstanding models for the study of physiological acclimation. As the implementation of such processes usually comes at a high bioenergetic cost, a mitochondrial/oxidative stress approach emerges as the most relevant approach when seeking to analyze whole-animal responses.

Subcellular evidences of redox imbalance in well-established populations of an endangered limpet. Reasons for alarm?

Intertidal species are more vulnerable to anthropogenic disturbances than others inhabiting subtidal and offshore habitats. Coastal development frequently results in trace-metal pollution. For endangered species such as Patella ferruginea it can be a high risk that leads local populations to extinction.