Extreme Environments Research Articles

Seasonal Gene Profiling in Tuz Lake with Regard to Biogeochemical Cycling

Tuz Lake, a thalassohaline lake with a salt rate of 32%, is a unique habitat for a halophilic microbiome. Culture-dependent and independent methods have been applied to identify prokaryotic microbial diversity in Tuz Lake. However, the key processes and genes involved in biogeochemical cycles in Tuz Lake have not been investigated seasonally. The aim of the study is to investigate seasonal gene profiling in Tuz Lake associated with biogeochemical cycling and thereby reveal more about the ecosystem dynamics of this extreme environment. Therefore, the PICRUSt2 tool was applied to analyze the metabolic function of archaeal and bacterial diversity in Tuz Lake. As a result of metabolic functions based on 16S rDNA amplicon sequencing data, it was observed that methane production by H2 and CO2 by anaerobic archaea in Tuz Lake was the predominant methanogenesis pathway. It was determined that sulfur oxidation was the dominant sulfur metabolism, while the reductive citric acid cycle was the dominant carbon fixation pathway.

A low-noise, radiation-hardened charge-sensitive amplifier for Silicon carbide neutron detector

Silicon carbide(SiC) neutron detectors can be applied to extreme environments with high temperature and strong radiation. The total noise factor is most significantly influenced by the noise factor of the first stage in a cascade amplifier. Hence, the preamplifier must exhibit exceptional noise performance. The readout circuit is inevitably exposed to the influence of radiation, which may result in temporary or even permanent failure of electronic systems. The connection method between the SiC neutron detector and the readout circuit is typically DC-coupled. When the sensor is working, the leakage current generated by the sensor will enter the input end of the CSA and change the baseline position of the CSA. In this paper, a low-noise CSA with leakage current compensation circuit(LCC) is presented. The circuit’s voltage-to-charge amplification is 2.98mV/fC, and the error due to nonlinearity is below 0.01%. Without considering the input parasitic capacitance, ENC is 43.12e-. In addition, the circuit also has good radiation resistance and leakage current compensation function. It is implemented and simulated in the DB Hitek 0.18μm CMOS process model.

An all paper based triboelectric nanogenerators with high output performance in extreme environment manufactured by multi-layer papers forming technology

Triboelectric nanogenerators (TENGs) are regarded as a promising technology to drive the development of flexible/wearable electronics and self-powering sensor. Application of cellulose paper as the triboelectric positive materials makes TENGs more environmentally friendly. However, the limited output and stability in harsh environments and oxidation and corrosion of the metal electrodes have limited the practical application of cellulose paper based triboelectric nanogenerators (CPTENGs). Here, we have integrated cellulose paper-based triboelectric material and electrode in one sheet by using multi-layer forming technology in paper industry; the upper triboelectric layer shows excellent triboelectric positive performance, hydrophobicity and acid and alkali resistance, while the bottom electrode exhibits promise conductivity. The all CPTENGs can yield a maximum open-circuit voltage (VOC) of 227.1 V, a short-circuit current (ISC) of 6.9 μA. Furthermore, the VOC values of the all CPTENGs increase from 0.02 V to 225.1 V at the load resistance of 100 Ω ∼ 10 GΩ; and a power density of 520 mW·m−2 is also obtained at a load resistance of 30 MΩ. Moreover, the VOC of CPTENGs not only retains up to 78 % of its initial value at a high relative humidity of 90 %, but also almost maintains unchanged in a wide range of the pH environment (pH = 1 ∼ 13). More importantly, the CPTENGs can be readily matched with paper-based zinc supercapacitor (P-ZISC) to act as an all paper based self-charging power system (PSCPS). The PSCPS is capable of driving various miniaturized electronics, such as electronic watch, temperature/humidity indicator, demonstrating its potential application in a sustainable power source for portable and green electronics.

Temperature dependence tensile behaviors of additively manufactured GH4099 Ni-based superalloy

Additive manufacturing was currently widely used to fabricate complex-shaped superalloy components for extreme environment applications. To replace the components prepared by the traditional approaches, it is crucial to ensure the reliability of AMed superalloys, especially in a thermal-stress environment. In this work, the high-temperature tensile properties of AMed GH4099 nickel-based superalloy are studied to establish the relationships among deformation temperatures, mechanisms, and failure responses. The results show that the deformation mechanisms at 600 °C are mainly cross-slip of the slip bands and arrays, which induced a ductile fracture. Increasing the tensile temperature will cause a shift of the dislocation movement from cross-slip to Orowan looping and stacking fault shearing to dislocation entangles-recovery-recrystallization, and the fracture mode transformed from pure ductile to mixed ductile-brittle. Additionally, the neighboring grain boundaries and the carbide-grain boundary bondings will also change with the temperature, which is further linked to the mediate-temperature brittleness and high-temperature abnormal plasticity of this superalloy.

A reference-grade genome of the xerophyte Ammopiptanthus mongolicus sheds light on its evolution history in legumes and drought-tolerance mechanisms

Plants that grow in extreme environments represent unique sources of stress-resistance genes and mechanisms. Ammopiptanthus mongolicus (Leguminosae) is a xerophytic evergreen broadleaf shrub native to semi-arid and desert regions; however, its drought-tolerance mechanisms remain poorly understood. Here, we report the assembly of a reference-grade genome for A. mongolicus, describe its evolutionary history within the legume family, and examine its drought-tolerance mechanisms. The assembled genome is 843.07 Mb in length, with 98.7% of the sequences successfully anchored to the nine chromosomes of A. mongolicus. The genome is predicted to contain 47 611 protein-coding genes, and 70.71% of the genome is composed of repetitive sequences; these are dominated by transposable elements, particularly long-terminal-repeat retrotransposons. Evolutionary analyses revealed two whole-genome duplication (WGD) events at 130 and 58 million years ago (mya) that are shared by the genus Ammopiptanthus and other legumes, but no species-specific WGDs were found within this genus. Ancestral genome reconstruction revealed that the A. mongolicus genome has undergone fewer rearrangements than other genomes in the legume family, confirming its status as a “relict plant”. Transcriptomic analyses demonstrated that genes involved in cuticular wax biosynthesis and transport are highly expressed, both under normal conditions and in response to polyethylene glycol-induced dehydration. Significant induction of genes related to ethylene biosynthesis and signaling was also observed in leaves under dehydration stress, suggesting that enhanced ethylene response and formation of thick waxy cuticles are two major mechanisms of drought tolerance in A. mongolicus. Ectopic expression of AmERF2, an ethylene response factor unique to A. mongolicus, can markedly increase the drought tolerance of transgenic Arabidopsis thaliana plants, demonstrating the potential for application of A. mongolicus genes in crop improvement.

Energy-efficient rapid additive manufacturing of complex geometry ceramics

Energy-intensive industries are one of the key greenhouse gas emitters, and decarbonization of such industries is a top priority to promote global sustainability. As one of the top energy-intensive industries, ceramic manufacturing industries are urged to boost energy efficiency in ceramic structure production. In this paper, we present a rapid and low carbon footprint strategy for freeform manufacturing spatial ceramic composites. Our approach integrates layer-by-layer deposition, photothermal in-situ solidification, and self-sustaining ceramization, enabling consolidation using only 1920 J energy. Compared to state-of-the-art processes, energy consumption can be reduced by over 100-fold, resulting in an estimated 1000-fold decrease in CO2 emissions. This energy-efficient process also demonstrates the rapid fabrication of ceramic gyroid heat exchangers, capable of withstanding extreme environments.

Design of a Flexure-Based Flywheel for the Storage of Angular Momentum and Kinetic Energy

The flywheel is a widespread mechanical component used for the storage of kinetic energy and angular momentum. It typically consists of cylindrical inertia rotating about its axis on rolling bearings, which involves undesired friction, lubrication, and wear. This paper presents an alternative mechanism that is functionally equivalent to a classical flywheel while relying exclusively on limited-stroke flexure joints. This novel one-degree-of-freedom zero-force mechanism has no wear and requires no lubrication: it is thus compatible with extreme environments, such as vacuum, cryogenics, or ionizing radiation. The mechanism is composed of two coupled pivoting rigid bodies whose individual angular momenta vary during motion but whose sum is constant at all times when the pivoting rate is constant. The quantitative comparison of the flexure-based flywheel to classical ones based on a hollow cylinder as inertia shows that the former typically stores 6 times less angular momentum and kinetic energy for the same mass while typically occupying 10 times more volume. The freedom of design of the shape of the rigid bodies offers the possibility of modifying the ratio of the stored kinetic energy versus angular momentum, which is not possible with classical flywheels. For example, a flexure-based flywheel with rigid pivoting bodies in the shape of thin discs stores 100 times more kinetic energy than a classical flywheel with the same angular momentum. A proof-of-concept prototype was successfully built and characterized in terms of reaction moment generation, which validates the presented analytical model.

Synergy of Spall Strength and Toughness in Nanograined Metals.

Under shock loading, the spall strength of nanocrystals exhibits intricate grain-size effects due to the presence of abundant grain boundary and dislocation activities. However, the influence of size on spall toughness and void evolution has been largely overlooked. This study employs molecular dynamics simulations to investigate the damage accumulation characteristics of nanocrystalline aluminum across various grain sizes. Unlike the trade-off observed in quasi-static loading conditions, our study reveals a consistency in which grain size governs both nanovoid nucleation and coalescence, yielding a novel spall strength-toughness synergy. These insights highlight grain sizes that are particularly susceptible to spall fracture, offering a crucial understanding of nanocrystal failure mechanisms in extreme environments.

Consequences of Exposure to Hypobaric Hypoxia Associated with High Altitude on Spermatogenesis and Seminal Parameters: A Literature Review.

Preclinical research has provided compelling evidence indicating that exposure to hypobaric hypoxia (HH) results in a deterioration of spermatogenesis. This adverse effect extends to the underlying molecular mechanisms, progressively leading to impairments in the seminiferous epithelium and germ cells and alterations in semen parameters. Indeed, several studies have demonstrated that animals exposed to HH, whether in natural high-altitude environments or under simulated hypoxic conditions, exhibit damage to the self-renewal and differentiation of spermatogenesis, an increase in germline cell apoptosis, and structural alterations in the seminiferous tubules. One of the primary mechanisms associated with the inhibition of differentiation and an increase in apoptosis among germ cells is an elevated level of oxidative stress, which has been closely associated with HH exposure. Human studies have shown that individuals exposed to HH, such as mountaineers and alpinists, exhibit decreased sperm count, reduced motility, diminished viability, and increased sperm with abnormal morphology in their semen. This evidence strongly suggests that exposure to HH may be considered a significant risk factor that could elevate the prevalence of male infertility. This literature review aims to provide a comprehensive description and propose potential mechanisms that could elucidate the infertility processes induced by HH. By doing so, it contributes to expanding our understanding of the challenges posed by extreme environments on human physiology, opening new avenues for research in this field.

Dryland microbiomes reveal community adaptations to desertification and climate change.

Drylands account for 45% of the Earth's land area, supporting approximately 40% of the global population. These regions support some of the most extreme environments on Earth, characterized by extreme temperatures, low and variable rainfall, and low soil fertility. In these biomes, microorganisms provide vital ecosystem services and have evolved distinctive adaptation strategies to endure and flourish in the extreme. However, dryland microbiomes and the ecosystem services they provide are under threat due to intensifying desertification and climate change. In this review, we provide a synthesis of our current understanding of microbial life in drylands, emphasizing the remarkable diversity and adaptations of these communities. We then discuss anthropogenic threats, including the influence of climate change on dryland microbiomes and outline current knowledge gaps. Finally, we propose research priorities to address those gaps and safeguard the sustainability of these fragile biomes.

Evolutionary accessibility of random and structured fitness landscapes

Biological evolution can be conceptualized as a search process in the space of gene sequences guided by the fitness landscape, a mapping that assigns a measure of reproductive value to each genotype. Here, we discuss probabilistic models of fitness landscapes with a focus on their evolutionary accessibility, where a path in a fitness landscape is said to be accessible if the fitness values encountered along the path increase monotonically. For uncorrelated (random) landscapes with independent and identically distributed fitness values, the probability of existence of accessible paths between genotypes at a distance linear in the sequence length L becomes nonzero at a nontrivial threshold value of the fitness difference between the initial and final genotypes, which can be explicitly computed for large classes of genotype graphs. The behaviour of uncorrelated random landscapes is contrasted with landscape models that display additional, biologically motivated structural features. In particular, landscapes defined by a tradeoff between adaptation to environmental extremes have been found to display a combinatorially large number of accessible paths to all local fitness maxima. We show that this property is characteristic of a broad class of models that satisfy a certain global constraint, and provide further examples from this class.

Analysis of UAV data communication stability method in extreme environment

In order to get in touch with the affected area smoothly after the disaster, this paper uses drones as air base stations. Their high mobility and sensitivity make them apt for such critical roles. However, during extreme weather conditions, these unmanned aerial vehicles (UAVs) encounter various challenges that can impair their stability and, consequently, their ability to serve as reliable air base stations. As a result, signal transmission can be interrupted or severely limited. Among the common factors affecting UAV stability are strong winds, temperature fluctuations, heavy rainfall, and electromagnetic interference. These factors can cause the UAVs to deviate from their intended flight paths, drop in altitude, or even lose connection with the ground control. As a consequence, the reliability of communication, so critical in emergency situations, gets compromised. To address the problem of degraded UAV stability, several solutions have been proposed and implemented. One approach involves enhancing the drone's onboard stabilization systems, incorporating advanced algorithms that allow it to autonomously adjust to environmental changes. Another strategy is the deployment of a network of drones, ensuring redundancy. If one drone faces difficulties, another can take over, maintaining the communication link. Furthermore, advances in materials science have led to the development of UAVs with more robust structures, capable of withstanding the rigors of adverse weather conditions. Lastly, the use of ground-based boosters or repeaters can amplify signals, ensuring that even if a UAV's transmission is weak, the communication remains uninterrupted.

Salt and heat stress enhances hydrogen production in cyanobacteria.

Cyanobacteria are among the most suitable organisms for the capture of excessive amounts of CO2 and can be grown in extreme environments. In our research we use the single-celled freshwater cyanobacteria Synechococcus elongatus PCC7942 PAMCOD strain and Synechocystis sp. PCC6714 for the production of carbohydrates and hydrogen. PAMCOD strain and Synechocystis sp. PCC6714 synthesize sucrose when exposed to salinity stress, as their main compatible osmolyte. We examined the cell proliferation rate and the sucrose accumulation in those two different strains of cyanobacteria under salt (0.4M NaCl) and heat stress (35 0C) conditions. The intracellular sucrose (mol sucrose content per Chl a) was found to increase by 50% and 108% in PAMCOD strain and Synechocystis sp. PCC6714 cells, respectively. As previously reported, PAMCOD strain has the ability to produce hydrogen through the process of dark anaerobic fermentation (Vayenos D, Romanos GE, Papageorgiou GC, Stamatakis K (2020) Photosynth Res 146, 235-245). In the present study, we demonstrate that Synechocystis sp. PCC6714 has also this ability. We further examined the optimal conditions during the dark fermentation of PAMCOD and Synechocystis sp. PCC6714 regarding H2 formation, increasing the PAMCOD H2 productivity from 2 nmol H2 h- 1 mol Chl a- 1 to 23 nmol H2 h- 1 mol Chl a- 1. Moreover, after the dark fermentation, the cells demonstrated proliferation in both double BG-11 and BG-11 medium enriched in NaNO3, thus showing the sustainability of the procedure.

PVD coating strategies: Developing a combination of AlCrN and AlTiSiN for enhanced surface performance during threading of super duplex stainless steel

Super duplex stainless steel (SDSS) is one of the difficult-to-machine materials due to its high tendency to work-harden and low thermal conductivity. According to recent findings, PVD hard coatings based on Al, Cr, and Ti are recommended for SDSS machining. In this work, three different PVD coating systems were applied for the threading process of SDSS. Monolayer Al50Cr50N, Al60Cr40N, and multilayer Al60Cr40N/Al50Ti45Si5N were deposited on cemented carbide inserts. This paper highlighted the effect of alloying and coating architecture design on the cutting tools' mechanical properties, tribological characteristics, and wear performance. A novel balanced combination of AlCrN/AlTiSiN multilayer coating with a Si content of 5 at. % was proposed, and it exhibited improved adhesion, beneficial mechanical properties, and superior cutting tool life. Furthermore, tribological characteristics under extreme environments were analyzed through a heavy-load, high-temperature tribometer, as well as XPS and AES measurements. The surface integrity of workpiece material machined by various coatings was also examined through microstructure, microhardness, and residual stress measurements. The depth profiles of residual stress reveal that the machining process significantly impacts the outcome, influenced by the tribological properties of the coatings. Specifically, the AlCrN/AlTiSiN coating exhibits a minimal effect on the surface. These investigations enhance the comprehension of the mechanisms that cause material mechanical surface transformation in threading operations, contributing to a deeper understanding of machining processes.

Climate and soil stressed elevation patterns of plant species to determine the aboveground biomass distributions in a valley-type Savanna.

Extreme environments such as prolonged high temperatures and droughts can cause vulnerability of vegetation ecosystems. The dry-hot valleys of Southwestern China, known for their extremely high annual temperature, lack of water, and unique non-zonal "hot island" habitat in the global temperate zone, provide exceptional sites for studying how plant adapts to the prolonged dry and hot environment. However, the specific local biotic-environment relationships in these regions remain incompletely elucidated. The study aims to evaluate how valley-type Savanna vegetation species and their communities adapt to long-term drought and high-temperature stress environments. The study investigated the changes in species diversity and communities' aboveground biomass of a valley-type Savanna vegetation along an elevation gradient of Yuanmou dry-hot valley in Jinsha River basin, southwest China. Subsequently, a general linear model was utilized to simulate the distribution pattern of species diversities and their constituent biomass along theelevation gradient. Finally, the RDA and VPH mothed were used to evaluate the impacts and contributions of environmental factors or variables on the patterns. The field survey reveals an altitudinal gradient effect on the valley-type Savanna, with a dominant species of shrubs and herbs plants distribution below an elevation of 1700m, and a significant positive relationship between the SR, Shannon-Wiener, Simpson, and Pielou indices and altitudes. Relatively, the community aboveground biomass did not increase significantly with elevation, which was mainly due to a decreased biomass of herbaceous plants along the elevation. Different regulators of shrub-herbaceous plant species and their functional groups made different elevation patterns of species diversity and aboveground biomass in valley-type Savannas. Herbaceous plants are responsible for maintaining species diversity and ensuring stability in the aboveground biomass of the vegetation. However, the influence of shrubs on aboveground biomass became more pronounced as environmental conditions varied along the altitudinal gradient. Furthermore, species diversity was mainly influenced by soil and climatic environmental factors, whereas community biomass was mainly regulated by plant species or functional groups. The study demonstrates that the spatial pattern of valley-type Savanna was formed as a result of different environmental responses and the productive capacity of retained plant species or functional groups to climate-soil factors, highlighting the value of the Yuanmou dry-hot Valley as a microcosm for exploring the intricate interactions between vegetation evolution and changes in environmental factors.

Heat Transfer by Sweat Droplet Evaporation.

Sweating regulates the body temperature in extreme environments or during exercise. Here, we investigate the evaporative heat transfer of a sweat droplet at the microscale to unveil how the evaporation complexity of a sweat droplet would affect the body's ability to cool under specific environmental conditions. Our findings reveal that, depending on the relative humidity and temperature levels, sweat droplets experience imperfect evaporation dynamics, whereas water droplets evaporate perfectly at equivalent ambient conditions. At low humidity, the sweat droplet fully evaporates and leaves a solid deposit, while at high humidity, the droplet never reaches a solid deposit and maintains a liquid phase residue for both low and high temperatures. This unprecedented evaporation mechanism of a sweat droplet is attributed to the intricate physicochemical properties of sweat as a biofluid. We suppose that the sweat residue deposited on the surface by evaporation is continuously absorbing the surrounding moisture. This route leads to reduced evaporative heat transfer, increased heat index, and potential impairment of the body's thermoregulation capacity. The insights into the evaporative heat transfer dynamics at the microscale would help us to improve the knowledge of the body's natural cooling mechanism with practical applications in healthcare, materials science, and sports science.

Elastic, antiflaming phenolic aerogels for advanced thermal protection at extreme environments

In practical applications, thermal protection demands materials with reliable structural stability under extreme conditions. Phenolic aerogels exhibit remarkable thermal protection capabilities; however, their inherent brittleness and porous structure make them susceptible to catastrophic failure when subjected to mechanical stresses or thermal oxidation. To address this, robust phenolic composite (PFR@SiO2) aerogels were synthesized through a three-step process involving sol-gel generation, ambient-pressure drying, and chemical vapor deposition. The resulting PFR@SiO2 aerogels display impressive mechanical properties, as well as a high degree of flame resistance. Furthermore, under fatigue stress/strain cycling tests or ultrahigh-temperature oxidation circumstance, such phenolic composite aerogels also exhibit exceptional structural stability. Overall, these combined properties position the PFR@SiO2 aerogels as a promising material system for robust thermal superinsulation under extreme conditions.

Design and multimodal locomotion plan of a hexapod robot with improved knee joints

AbstractHexapod robots represent complex and highly redundant robotic systems capable of handling various tasks in extreme environments, such as planetary exploration and disaster response. To enhance the terrain adaptability and maneuverability of hexapod robots, we present a novel multimodal hexapod robot in this research. Our multimodal hexapod robot design incorporates knee joints with an improved multiparallel quadrilateral transmission mechanism, addressing singularity issues commonly encountered in legged robots. This enhancement not only improves the mechanical transmission characteristics of the knee joints but also increases the workspace of a single leg to achieve leg‐arm reuse functionality. In the presence of flat and structured terrain, the robot seamlessly switches to a wheeled locomotion mode, enabling swift traversal. Conversely, when faced with rough and unstructured terrain, it transitions into a legged mode, employing adaptive gait stability to navigate effectively. A novel operational mode in which the hexapod robot utilizes four legs for body support, while the remaining two legs are repurposed as arms is proposed. This innovative approach empowers the hexapod robot to perform dual‐arm manipulation without the need for additional degrees of freedom for the manipulator. To validate the effectiveness of our designed hexapod robot and multimodal motion planning algorithm, comprehensive experimental testing has been conducted, demonstrating the practicality and versatility of our system.

Fecal microbiota reveal adaptation of herbivores to the extreme environment of the Qinghai–Tibet Plateau

AbstractBackgroundGut microbiota is pivotal in regulating hosts' biological processes and maintaining homeostasis, but knowledge about its role in wild herbivores in extreme environments remains limited.MethodsGut bacteria and fungi were sequenced in ruminant (Chiru and Yak) and nonruminant (Kiang) herbivores on the Qinghai–Tibet Plateau, and their community structure, co‐occurrence networks, functions, and assembly mechanisms were investigated using multivariate ecological and statistical methods.ResultsKiang had lower gut microbial diversity than Chiru and Yak. Bacterial host‐specific exclusivity was greater than that of fungi. In addition to the evidence of glycan biosynthesis and carbohydrate metabolism, Chiru had a high Firmicutes/Bacteroidetes ratio and low animal pathogen abundance, suggesting better adaptation to the plateau's harsh environment. Additionally, members of gut microbiota tended to co‐occur rather than co‐exclude in all herbivores. Different network complexity and stability patterns were observed between bacterial and fungal communities. Furthermore, gut bacterial assembly was primarily controlled by stochastic dispersal limitation and drift, whereas fungal assembly was primarily controlled by deterministic homogeneous selection except in Chiru.ConclusionsOn the Qinghai–Tibet Plateau, Chiru and Yak exhibit more diverse gut microbiota and more diverse metabolic functions than Kiang, and gut bacteria are more divergent than gut fungi in these herbivores.

Differential tissue immune stimulation through immersion in bacterial and viral agonists in the Antarctic Notothenia rossii

The genome evolution of Antarctic notothenioids has been modulated by their extreme environment over millennia and more recently by human-caused constraints such as overfishing and climate change. Here we investigated the characteristics of the immune system in Notothenia rossii and how it responds to 8 h immersion in viral (Poly I:C, polyinosinic: polycytidylic acid) and bacterial (LPS, lipopolysaccharide) proxies. Blood plasma antiprotease activity and haematocrit were reduced in Poly I:C-treated fish only, while plasma protein, lysozyme activity and cortisol were unchanged with both treatments. The skin and duodenum transcriptomes responded strongly to the treatments, unlike the liver and spleen which had a mild response. Furthermore, the skin transcriptome responded most to the bacterial proxy (cell adhesion, metabolism and immune response processes) and the duodenum (metabolism, response to stress, regulation of intracellular signal transduction, and immune system responses) to the viral proxy. The differential tissue response to the two proxy challenges is indicative of immune specialisation of the duodenum and the skin towards pathogens. NOD-like and C-type lectin receptors may be central in recognising LPS and Poly I:C. Other antimicrobial compounds such as iron and selenium-related genes are essential defence mechanisms to protect the host from sepsis. In conclusion, our study revealed a specific response of two immune barrier tissue, the skin and duodenum, in Notothenia rossii when exposed to pathogen proxies by immersion, and this may represent an adaptation to pathogen infective strategies.