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Probiotics are kinds of beneficial live microbes that impart beneficial effects on the host. Recent studies have proven that when given supplementation with probiotics, farmed fish showed improved disease prevention and growth promotion.

Aqueous electrolyte is one of the most favored choices for various high-energy, low-cost and safe batteries. However, the undesired parasitic hydrogen evolution reaction (HER), especially on high reactive metal anodes, brought by aqueous electrolyte remains the development bottleneck of these batteries. Here, introducing solvents to manipulate the hydrogen-bond network of aqueous electrolyte is proposed to suppress the parasitic HER. Significantly, theoretical simulations and experimental characterizations demonstrate that donor number of the solvents could serve as a descriptor to ability of confining the free water and reducing the water activity. The solvent additive with high donor number exhibits remarkable suppression on the self-discharge and hydrogen evolution of Al anodes in alkaline electrolyte, which endows a flow-based Al-air battery with an outstanding energy density of 3106.04 Wh kg−1. The findings not only provide a guidance on the rational design of aqueous electrolyte but also expand the application of high-donor solvents.

Metallic lithium (Li) is known to consider a critical role in next-generation rechargeable batteries. However, the uncontrolled growth of Li dendrites result in low Coulombic efficiency and safety issues in applications of Li metal batteries. High capacity and stable dense deposits of lithium metal are of great significant for high energy density battery. Herein, we propose a suitable degree of substitution for Carboxymethylcellulose Lithium (CMC-Li) as an artificial SEI layer, which has a high ionic transference number (0.66), high Young's modulus (24.6 GPa) and good lithiophilicity, then it can adapt to the volume changes of the lithium anode, enable superdense lithium deposits on Cu collector. The metallic lithium anode with CMC-Li films (CMC-Li@Li) delivers excellent cycling performance in the symmetrical cell at a large current density of 10 mA cm−2 and an areal capacity of 10 mAh cm−2 for almost 300 h. Moreover, the CMC-Li@Li||NCM613 full cell (N/P=2) delivers an initial specific capacity of 165 mAh g−1 with a high retention of 80% after 200 cycles.

Recently, the frequent salinity fluctuation has become a growing threat to fishes. However, the dynamic patterns of gene expression in response to salinity changes remain largely unexplored. In the present study, 18 RNA-Seq datasets were generated from gills of rainbow trout at different salinities, including 0 ‰, 6 ‰, 12 ‰, 18 ‰, 24 ‰ and 30 ‰. Based on the strict thresholds, we have identified 63, 1411, 2096, 1031 and 1041 differentially expressed genes in gills of rainbow trout through pairwise comparisons. Additionally, weighted gene co-expression network analysis was performed to construct 18 independent modules with distinct expression patterns. Of them, green and tan modules were found to be tightly related to salinity changes, several hub genes of which are known as the important regulators in taurine and glutamine metabolism. To further investigate their potential roles in response to salinity changes, taurine, glutamine, and their metabolism-related glutamic acid and α-ketoglutaric acid were accurately quantitated using liquid chromatography-tandem mass spectrometry analysis. Results clearly showed that their concentrations were closely associated with salinity changes. These findings suggested that taurine and glutamine play important roles in response to salinity changes in gills of rainbow trout, providing new insights into the molecular mechanism of fishes in salinity adaptation.

This study evaluated the effect of dietary taurine levels on growth, serum biochemical parameters, salinity adaptability, and antioxidant activity of rainbow trout (Oncorhynchus mykiss). Four diets were formulated with taurine supplements at 0, 0.5, 1, and 2% w/v (abbreviated as T(0), T(0.5), T(1), and T(2), respectively). Rainbow trouts (initial weight of 80.09 ± 4.72 g) were stocked in tanks (180 L capacity), and were fed these diets for six weeks and subsequently underwent salinity acclimation. Physiological indicators were determined before salinity acclimation at 1, 4, 7, and 14 days afterwards. Results showed that there were no significant differences in growth performance (final mean weight ranged from 182.35 g to 198.48 g; percent weight gain was between 127.68% and 147.92%) of rainbow trout in freshwater stage, but dietary taurine supplement significantly increased serum-free taurine content. After entering seawater, the Na(+)-K(+)-ATPase activity of T(2) group returned to its freshwater levels, and the serum cortisol content was significantly higher than T(0) and T(0.5) groups. At the end of this experiment, the liver superoxide dismutase activity in the T(0) and T(0.5) groups was significantly lower than in the T(1) and T(2) groups, and the liver catalase in the T(0) group was the lowest whereas that in the T(2) group was the highest. Muscle malondialdehyde content was the highest in the T(0) group, and the lowest in the T(2) group. Based on the results of this study, supplement of dietary taurine (0.5–2%) enhanced the salinity tolerance in rainbow trout, which increased with the higher taurine concentration.

The study investigated the effects of seawater acclimation at constant and diel temperatures on the growth, osmoregulation, and branchial phospholipid fatty acid (PLFA) composition in rainbow trout (Oncorhynchus mykiss). The fish (initial weight, 62.28 ± 0.41 g) were reared at a constant 13.0 °C (CT) or with a diel cycle of either 13.0 ± 1.0 °C (VT2) or 13.0 ± 2.0 °C (VT4) for 6 weeks, and subsequently subjected to seawater acclimation. Diel temperature variations (of up to 4 °C) did not affect the growth rate of rainbow trout maintained in freshwater, but alleviated the impairment on the growth after seawater challenge. Under all temperature conditions, rainbow trout were well prepared to seawater acclimation. The diel cyclic temperature resulted in fish with reduced fluctuations in plasma electrolyte levels, branchial Na+–K+ ATPase activity, and plasma osmolality. In freshwater, the sum of the monounsaturated fatty acids was significantly higher in the VT4 relative to CT and VT2 treatment. Conversely, the sum of polyunsaturated fatty acids was significantly lower in the VT4 fish. After seawater transfer, the branchial PLFA profiles of the fish significantly changed, but those in CT and VT2 did not recover afterwards (the degree of unsaturation was downregulated). The PLFA composition of fish in the VT4 treatment appeared to be steadier under seawater acclimation. This study suggests that a diel cyclic temperature (13.0 ± 2.0 °C) can alleviate the impairment of growth, enhance osmoregulation capability, and improve the stability of the branchial PLFA composition in rainbow trout after seawater acclimation.

This physiological study aimed to evaluate the effects of dietary docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on the fatty acid composition and digestive enzyme activities of rainbow trout (Oncorhynchus mykiss) during salinity acclimation. Rainbow trout with an average initial weight of 90.61 g ±9.25 g were fed diets with the quantities of DHA and EPA equaling to 0.54%, 0.95%, 1.40% and 1.79% (abbreviated as DE-0.54, DE-0.95, DE-1.40, and DE-1.79, respectively) for eight weeks, after which the gastric and intestinal fatty acids composition were analyzed. Subsequently, the fish underwent salinity acclimation. On days 1, 4, 7, and 14 after the freshwater was replaced by seawater and at the end of the 8-week period, gastric and intestinal digestive enzyme activities were determined. The results showed that the gastric and intestinal DHA and EPA contents of the fish were positively correlated to their dietary DHA and EPA levels. Low dietary DHA and EPA levels inhibited the protease activity of rainbow trout. Fish in the DE-0.54 group increased the lipase activity to enhance the utilization of lipids maybe due to the inadequate essential fatty acids for fish in this group. Hence, rainbow trout in the DE-0.54 group failed to maintain suitable activities of digestive enzymes after salinity acclimation. Therefore, a diet with minimum 0.95% DHA and EPA levels is necessary for rainbow trout during salinity acclimation.

3D carbon frameworks are promising hosts to achieve highly reversible lithium (Li) metal anodes, whereas insufficient effects are attributed to their single electron conductivity causing local aggregating of electron/Li

This study was conducted to evaluate the effect of dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels on the fatty acid composition, salinity tolerance and antioxidant status of rainbow trout (Oncorhynchus mykiss). Four diets were formulated with total EPA and DHA contents of 5.41, 9.55, 13.97 and 17.88 g/kg (abbreviated as ED‐5.41, ED‐9.55, ED‐13.97 and ED‐17.88 respectively). Rainbow trout (initial weight of 90.61 ± 9.25 g) were fed the experimental diets for 8 weeks to accumulate significant differences in fatty acid composition and subsequently underwent salinity acclimation. Our results indicated that high dietary EPA and DHA significantly improved the EPA and DHA content in fish tissues. The serum osmolality of fish returned to their freshwater values in the ED‐9.55, ED‐13.97 and ED‐17.88 groups. The Na⁺, K⁺‐ATPase (NKA) activity of fish in the ED‐13.97 group changed dramatically to adapt the fish to the hypertonic environment. Moreover, there was no significant difference in the serum cortisol concentration and liver catalase (CAT) activity of fish in the ED‐13.97 group during salinity acclimation. The liver superoxide dismutase (SOD) activity in the ED‐13.97 group was significantly higher than that in ED‐5.41 and ED‐9.55 groups at the end of salinity acclimation. The muscle malondialdehyde (MDA) content in the ED‐13.97 group was significantly lower than that in the ED‐17.88 group before salinity acclimation and significantly lower than the ED‐5.41 and ED‐17.88 groups on day 7 of acclimation. The results of this study indicate that the rainbow trout in the ED‐13.97 group exhibited optimal salinity acclimation performance.

In order to meet the demand of salmon market, Chinese scientists and entrepreneurs are working on salmon mariculture far offshore in the Yellow Sea, China. Rainbow, steelhead trout and Atlantic salmon were selected as the main culture species. The aims of the present study were as follows: (a) investigate the effect of the salinity acclimation method on the growth, osmoregulation and energy budget in two forms of Oncorhynchus mykiss, rainbow and steelhead trout and (b) explore the optimal size of steelhead trout for the seawater entry. In trial I, rainbow (mean = 99.44 g) and steelhead trout (mean = 99.01 g) were reared for 40 days after undergoing salinity acclimation at three rates: an abrupt increase in salinity from 0 to 30 g/L (T30); an abrupt increase in salinity to 14 g/L, followed by a daily increase of 2 g/L (T2) or 6 g/L (T6) until reaching 30 g/L; and no salinity exposure (control treatment) (T0). In trial II, steelhead trout with body weights of approximately 100 and 400 g were cultured for 60 days with two treatments, T0 and T2, and the specific growth rate (SGR) was calculated every 10 days. In trial I, in both kinds of fish, the optimal growth performance, survival rate, osmoregulation and energy budget were observed in the T0 treatment, followed by the T2 treatment. These results indicate that O. mykiss with a body weight of approximately 100 g can adapt to sea water with a gradual transition (T2), but they are still not suitable for the seawater entry because of low growth. Based on the recorded SGRs in trial II, our formulated regression formula revealed that approximately 200 g is the optimal size of steelhead trout for the transition to sea water.

In the present study, juvenile rainbow trout (Oncorhynchus mykiss) were acclimated at 5 temperatures. Fish in the control group (C0) were reared at a constant temperature (16°C); trout in four other treatments (A0, A3, A6, and A9) were acclimated to a high temperature (22°C) for 0, 3, 6, and 9 d, respectively, and then returned to normal temperature (16°C) for 7 d. The temperature was then raised to 20°C and the fish were cultured for 40 d. The results showed that the growth rates of A3, A6, and A9) were higher than that of A0 but lower than that of C0. The growth rate of A9 was the highest among the 4 acclimation groups. The activities of serum transaminase and liver antioxidant enzyme significantly increased during acclimation. At the beginning of growth, the activities of enzymes were lower in A3, A6, and A9 with the lowest in A9. In addition, the transcript abundance of heat shock protein (HSP) 60 gene in A9 was not significantly different from that of C0 during growth. HSP70 in A9 significantly increased at the beginning and returned to that of C0 at the end. Our findings indicated that pre-acclimation improved the high temperature tolerance with the best effectiveness observed at 22°C for 9 d. A possible mechanism underlining such phenomenon is the improvement of antioxidant defense system.

Salinity is an important environmental factor that directly affects the survival of aquatic organisms, including fish. However, the underlying molecular mechanism of salinity adaptation at post-transcriptional regulation levels is still poorly understood in fish. In the present study, 18 RNA-Seq datasets were utilized to investigate the potential roles of alternative splicing (AS) in response to different salinity environments in the livers of three euryhaline teleosts, including turbot (

Redox flow batteries (RFBs) stand out as one of the most promising candidates for stationary energy storage with high scalability and separate control over energy and power. Nevertheless, the widespread application of commercial RFBs is restricted by the relatively high stack cost as well as the uncompetitive performance metrics. Developing new-concept RFBs beyond conventional design frameworks can effectively alleviate these concerns. In this review, we aim to provide comprehensive fundamentals of new chemistries in RFBs toward widespread practical applications. We first introduce the technological features of conventional RFBs, followed by the specific cell architectures and possible optimization approaches on each component. We further review in detail the design principles and demonstrations of the newly developed RFBs, including novel redox species, integrated energy systems, and innovative cell structures. We conclude with a summary on the current challenges and future perspectives in this research field.

Significance Oxidation and reduction steps in catalysis are always in series, and excellent activity can be achieved when they occur in close proximity. Photooxidation and photoreduction are generally separated and rarely in series. This work develops defect engineering at the metal–oxide interface to make photooxidation sites close to photoreduction sites. Taking solar hydrogen production from aqueous alcohols over Pt/ T i O 2 as an example, the proximity effect triggers unusual reactions and thus increases hydrogen yield per photon from 0.046 to 1.28. Our study provides a direction for the development of efficient photocatalysis.

In this study, the changes of the fatty acid composition of phospholipid in different tissues (muscle, heart, brain and spleen) of steelhead trout (Oncorhynchus mykiss) were analyzed when the water temperature decreased gradually from 16°C to 12°C, 8°C, 6°C, 4°C, 2°C and 1°C. Three fish individuals each tank (average weight 70.32 g ± 9.12 g) were collected and used to analysis at each designed temperatures. At normal temperature (16°C), the fatty acid composition of phospholipid of muscle and heart was similar each other. The highest concentration of saturate fatty acids (SFA) was found in the phospholipid of spleen. The brain phospholipid contained higher oleic acid (18:1n9) than the phospholipid of other tissues at 16°C. When the environmental temperature decreased, the concentration of unsaturated fatty acids of phospholipids in all tissues increased, and accordingly the ratio pf the unsaturated to saturated fatty acids (U/S) and unsaturation index (UI) increased, indicating that steelhead trout can compensate temperature- dependent changes in membrane fluidity by remodeling the fatty acid composition of phospholipids. The changes in the fatty acid composition of phospholipid were tissue-specific. At the early stages of the experiment (16°C to 8°C), the fatty acid composition of phospholipid changed remarkably in muscle, heart, and spleen. When temperature decreased to less than 8°C, an obvious response of phospholipid fatty acid was observed in all tissues. The change of phospholipid composition of steelhead trout tissues may be affected by both cold stress and starvation when the temperature decreased to 2°C, and the change of phospholipid composition of muscle was very obvious.

This study examined the effect of different salinities (0, 5, 10, 15, 20, 25 and 30) on the growth performance and energy budget of juveniles of two different ecotypes of Oncorhynchus mykiss, landlocked rainbow trout and anadromous steelhead trout. In the 42 d experiment, fish were cultured in three replicate tanks per salinity treatment (eight fish per tank). At the end of the experiment, the growth of rainbow and steelhead trouts was significantly higher at salinities of 5 and 10, respectively, than at all other salinities. The protein, lipid and energy content of both ecotypes declined with the increase of salinity. Based on their energy budgets, the percentage of energy consumed for growth by rainbow and steelhead trouts were significantly higher at salinities of 5 (34.00% ± 1.69%) and 10 (43.76% ± 1.29%), respectively, than at all other salinities. The percentage of energy consumed for respiration by rainbow and steelhead trouts was lower at salinities of 5 (54.90% ± 1.77%) and 10 (46.73% ± 0.62%), respectively, than at all other salinities. Our results indicated that the salinity adaptation ability of juvenile steelhead trout was slightly better than that of juvenile rainbow trout, and salinities of 10 and 5, respectively, were most suitable for growth of these two fishes.

Solar energy is regarded as the most promising source of electricity considering its large magnitude on earth every day. The effective use of such an intermittent energy source relies on development of affordable, inexhaustible and clean solar energy conversion and storage technologies. Here, we design a novel solar-driven regenerative electrochemical system for simultaneous photoelectric energy harvesting and storage. With rational screening of redox species and comprehensive electrochemical study, a high Seebeck coefficient of −1.8 mV K−1 is achieved by solely exploiting earth-abundant materials based on the thermogalvanic effect. A high energy conversion efficiency (1.23%, and 11.9% versus the Carnot efficiency) is achieved under a low temperature gradient of 35 °C. Moreover, the durability of the proof-of-concept device has been examined under solar irradiation employing the bifunctional current collector/solar absorber with good electrical conductivity, efficient solar absorption and photothermal transduction. This innovative cell design integrating simultaneous energy conversion and storage represents an alternative approach towards cost-effective harnessing of solar energy and even more broad thermal energy in ambient environments.

Summary Recent development of high-energy-density organic-based redox flow batteries for large-scale energy storage systems is challenged by the stability and limited molar concentration of the redox-active molecules. Here, we report green and effective eutectic-based anolytes to achieve enhanced reversibility and high concentration through phthalimide derivatives. A nearly 6-fold increase in solubility can be achieved with the eutectic electrolytes composed of phthalimide derivatives, urea, and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The interaction between phthalimide derivatives and LiTFSI weakens the chemical bonds, facilitating the formation of eutectic electrolytes. Meanwhile, urea contributes to decreasing the viscosity of the eutectic solvent as well as to improving the reversibility of phthalimide radical anions generated during the electrochemical process. Compared with previously reported organic redox flow batteries, the resulting redox flow battery demonstrates comparable storage capacity but superior cycling stability, showing the promise of the eutectic-phthalimide-based organic molecules for high-performance organic redox flow batteries.

Florida pompano perform well on soy‐based, low‐animal protein diets. These diets may be improved through the use of enzymes as a feed supplement or as pretreatment of the soy product prior to inclusion. Novel soy products produced through enzyme treatment or fermentation often have higher protein content and lower levels of indigestible carbohydrates. Two trials were conducted to evaluate the potential of enzyme supplements. The first trial evaluated the effects of carbohydrase supplementation to diets based on two different soybean meals (commodity or selectively bred meal). Pompano fed the selected soybean had significantly improved growth rates and feed efficiency, while enzymatic supplementation had no significant effect on fish performance. However, enzyme supplementation increased phosphorus and energy retention when added to diets based on commodity soybean meal. Carbohydrase supplementation improved dry matter digestibility in commodity soy‐based diets but had no significant effect on selected soybean‐based diets. The second growth trial consisted of an increasing inclusion of an enzymatically treated soybean meal product (NutriVance). Results indicate that NutriVance can replace the totality of commodity soybean without impacting fish performance. Digestibility of the commodity soy, NutriVance, and a fermented soybean meal (Pepsoygen) was also evaluated, with no detectable difference in digestibility values.

This study was conducted to evaluate the critical thermal maximum (CTMax), the routine metabolism rate (MO2) and the limiting oxygen saturation (LOS) of three salmonids with four different body weights ranging from 16 g to 131 g. The CTMax was estimated at three different heating rates including 0.5°C min−1, 1°C h−1 and 2°C d−1. Results showed that the CTMax of maple trout (Oncorhynchus mykiss) was the highest, which was followed by steelhead trout (O. mykiss) and Atlantic salmon (Salmon salar). The CTMax of the salmonid fish decreased with the increment of body weight, and was significantly influenced by the heating rate. The MO2 of the salmonid fish increased with the increment of temperature, and decreased with the increment of body weight. Suffocation points of the fish decreased with increasing body weight and temperature. Steelhead trout was more tolerant to hypoxia than maple trout and Atlantic salmon, while the MO2 of Atlantic salmon was the highest among these three salmonids. The LOS of the fish generally had a positive trend with temperature and body weight, and the LOS of steelhead trout was significantly lower than that of maple trout and Atlantic salmon. In conclusion, maple trout was the most tolerant kind to high temperature, while steelhead trout was the most tolerant to hypoxia among three kinds of salmonids. Moreover, the abilities to tolerate higher temperature of three salmonids were affected by their body weight and the heating rate, while the abilities to tolerate hypoxia were influenced by their body weight and the water temperature.

This study investigated the fatty acid (FA) composition of gill and liver phospholipids in Steelhead trout (Oncorhynchus mykiss) (average weight: 75.45 ± 6.27 g) and Atlantic salmon (Salmo salar) (average weight: 72.89 ± 3.12 g) as water temperature decreased from 16 °C to 12 °C, 8 °C, 6 °C, 4 °C, 2 °C, and 1 °C. At normal temperature (16 °C), both gill and liver phospholipids of Atlantic salmon had lower saturated fatty acid (SFA) and higher unsaturated (UFA) compositions than those of Steelhead trout. Atlantic salmon was more sensitive to the temperature decline than Steelhead trout at the early stage of the experiment. Polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid (MUFA) contents of Atlantic salmon liver phospholipids significantly increased as temperature decreased from 16 °C to 12 °C. However, both PUFA and MUFA contents decreased significantly at temperatures below 4 °C. In contrast, there was only a negligible decrease in MUFA content in Steelhead trout liver phospholipids at 1 °C. Starvation and cold stress influenced liver phospholipid FA composition in Atlantic salmon but not in Steelhead trout, suggesting that the latter can better adapt to low temperatures. Changes in gill phospholipid composition in response to temperature fluctuations were species-specific. When the ambient temperature was below 8 °C, SFA content of gill phospholipids decreased whereas PUFA content increased and MUFA content was unaltered in Atlantic salmon. Although the FA composition of gill phospholipids in Atlantic salmon was altered at 6 °C, it remained stable as temperature further decreased. These results indicate that the FA composition of gill phospholipids in Atlantic salmon is less influenced by starvation stress than that of liver phospholipids. Moreover, fewer changes in FA composition were observed for gill as compared to liver phospholipids in both species of fish. Our results can be useful for optimizing Atlantic salmon and Steelhead trout aquaculture systems.

Background Rainbow trout is an economically important fish in aquaculture and is a model species in environmental physiology. Despite earlier research on the seawater adaptability of rainbow trout at different temperature regimes, the influence on the liver and intestine in this species is still unknown. Two trials were conducted to investigate the effects of constant and diel cyclic temperatures on phospholipid fatty acid (PLFA) composition in the liver and intestine of rainbow trout during seawater acclimation. Results At the end of growth trial 1, fish at 9 and 12.5 °C showed significantly higher ratios of unsaturated to saturated (U/S) and unsaturation index (UI) than those at 16 °C in liver and intestine phospholipids. After day 1 of seawater acclimation, the U/S, UI, and average chain length (ACL) of liver and intestinal phospholipids in fish at 16 °C significantly increased. Two weeks after seawater acclimation, the liver and intestinal PLFA composition adapted to salinity changes. In trial 2, significantly higher U/S, UI, and ACL were found in intestinal phospholipids at 13 ± 2 °C. On the first day after seawater acclimation, UI and ACL in liver phospholipids significantly increased at 13 °C, while fish at 13 ± 2 °C showed significantly decreased U/S, UI, and ACL in the intestine. At the end of growth trial 2, liver PLFA compositions were stable, whereas intestinal PLFA at 13 and 13 ± 1 °C showed significantly decreased U/S, UI, and ACL. A two-way analysis of variance and principal component analysis revealed significant effects of different constant temperatures, seawater acclimation, and their interaction on the liver and intestinal phospholipids, a significant effect of diel cyclic temperature on intestinal phospholipids, and the effects of seawater acclimation and its interaction with diel cyclic temperature on liver phospholipids. Conclusion Temperatures of 9 and 12.5 °C could elevate membrane fluidity and thickness in the liver and intestine of rainbow trout in freshwater, whereas no significant effects were found with diel temperature variations. After seawater acclimation, constant and diel cyclic temperatures significantly influenced the membrane fluidity and thickness of the liver and intestine. Compared with constant temperature, diel temperature variation (13 ± 2 °C) can enhance the adaptability of rainbow trout during seawater acclimation.

This study aimed to investigate the effects of different temperatures on seawater acclimation in rainbow trout (Oncorhynchus mykiss), in terms of growth performance, osmoregulatory capacity, and branchial phospholipid fatty acid (PLFA) composition. The fish (initial weight, 94.73 g) were reared at 9, 12.5, and 16 °C for 28 days, then acclimated to seawater, and subsequently reared for 14 days. Sampling points were on the last day in freshwater, and the 1st, 4th, 7th, and 14th days after the salinity reached 30. The results showed the final weight, percent weight gain, and specific growth rate of rainbow trout at 12.5 °C were significantly higher than those at 9 °C, while the thermal growth coefficient at 16 °C was significantly lower than that in other treatments. The branchial PLFA composition in rainbow trout changed more rapidly at 9 and 12.5 °C than at 16 °C. The branchial PLFA composition was significantly affected by temperature and salinity and their interaction. The polyunsaturated fatty acid content of phospholipids in the gill at 9 and 12.5 °C was significantly higher than those at 16 °C. Low temperature (9 °C) and seawater acclimation significantly increased the degree of unsaturation of membrane, enhancing membrane fluidity, which is related to Na+–K+ ATPase activity. Responses of plasma ion, Na+–K+ ATPase activity, and plasma glucose followed a similar pattern at different temperatures. Overall, the study suggests that 12.5 °C is the ideal temperature for seawater acclimation in rainbow trout.

Aquaculture is the fastest growing food production industry in terms of annual growth rate and has become an important contributor in supplying essential macro-and micro-nutrients for the global population. However, there is a great deal of uncertainty in its further development due to the high and increasing pressure of environmental challenges and of resource constraints. To achieve overall sustainable development of the aquaculture sector in China, the dominant producer of farmed seafood in the world, the priority is to clarify the sustainability of major aquaculture production systems (APSs) and to seek a holistic approach to improve their sustainability. Here the sustainability of ten major types of APSs in China, was evaluated comparatively by three objective and subjective methods involving eleven social, economic, environmental, and resource criteria. Accordingly, ecological intensification of aquaculture systems (ELIAS), integrating anthropogenic inputs with aquaculture ecosystem services, is proposed to improve the sustainability of these APSs. ELIAS that should be widely adopted by the multiple stakeholders provides a feasible solution to realize the goals of increasing aquaculture outputs with less negative environmental influence while saving energy at the same time.