A strategy that informs on countries' potential losses due to lack of climate action may facilitate global climate governance. Here, we quantify a distribution of mitigation effort whereby each ...country is economically better off than under current climate pledges. This effort-sharing optimizing approach applied to a 1.5 °C and 2 °C global warming threshold suggests self-preservation emissions trajectories to inform NDCs enhancement and long-term strategies. Results show that following the current emissions reduction efforts, the whole world would experience a washout of benefit, amounting to almost 126.68-616.12 trillion dollars until 2100 compared to 1.5 °C or well below 2 °C commensurate action. If countries are even unable to implement their current NDCs, the whole world would lose more benefit, almost 149.78-791.98 trillion dollars until 2100. On the contrary, all countries will be able to have a significant positive cumulative net income before 2100 if they follow the self-preservation strategy.
Cultured
Nibea albiflora
rarely die from cryptocaryoniasis. To explore the resistance of
N. albiflora
against the invasion of
Cryptocaryon irritans
, in this study, 40 g
N. albiflora
was artificially ...infected with
C. irritans
at a median lethal concentration (2050 theronts/g fish). The food intake, survival, relative infection intensity, and immobilization titer variation of serum and mucus at different time points after the infection were compared. Results showed that the ingestion of
N. albiflora
could be resumed only 1 day after feed deprivation by the disease, which indicated the quick resilience of
N. albiflora
.
N. albiflora
did not die out even if it was cultured continually for up to 15 days at 27 °C in a culture tank with a large quantity of
C. irritans
tomonts. It was because that, without any exterior force,
N. albiflora
could block the
C. irritans
cell proliferation, and then the pathogens disappear gradually. In vitro immobilization titer test results confirmed that the serum and mucus could directly eradicate
C. irritans
.
Large yellow croaker (Larimichthys crocea) is one of the most valuable marine fish in southern China. Given to the rapid development of aquaculture industry, the L. crocea was subjected to ciliate ...ectoparasite Cryptocaryon irritans. It therefore is indispensable and urgent to understand the mechanism of L. crocea host defense against C. irritans infection. In the present study, the extensively analysis at the transcriptome level for Cryptocaryoniasis in L. crocea was carried out. These results showed that 15,826,911, 16,462,921, and 15,625,433 paired-end clean reads were obtained from three cDNA libraries (A: 0 theronts/fish, B: 12,000 theronts/fish, and C: 24,000 theronts/fish) of the L. crocea immune-related tissues by Illumina paired-end sequencing technology. Totally, 30,509 unique transcript fragments (unigenes) were assembled, with an average length of 1715 bp. In B/A, C/A, and C/B pairwise comparison, 972, 900, and 1126 genes showed differential expression respectively. Differently expressed immune-related genes (DEIGs) were scrutinized, in B/A pairwise comparison, 48 genes showed differential expression, including 26 up-regulated genes and 22 down-regulated genes in B; in C/A pairwise comparison, there were 39 DEIGs, including 7 up-regulated genes and 32 down-regulated genes in C; in C/B pairwise comparison, 40 genes showed differential expression, including 11 up-regulated genes and 29 down-regulated genes in C. There were 16 DEIGs enriched KEGG pathways, in which the complement and coagulation cascades pathway was the top most DEIGs enriched pathway (B:A = 42; C:A = 28; C:B = 42). The coagulation and fibrinolytic system was in a highly active state after infected by C. irritans with non-lethal concentration; the alternative complement pathway may play an important role in the early stages of C. irritans infection. These results demonstrated that low-concentration infection can significantly induce the immunological response in fishes, however, when fishes were in fatal conditions, the immunity was suppressed.
•Analysis at the transcriptome level for cryptocaryoniasis in Larimichthys crocea.•30,509 unigenes were assembled, with an average length of 1715 bp.•Coagulation and fibrinolytic system was activated after non-lethal concentration C. irritans infection.•Alternative complement pathway plays an important role in the early stages of C. irritans infection.•High concentration infection can significantly suppress the immunity.
Marine mollusks are commonly subjected to heat stress. To evaluate the effects of heat stress on the physiological metabolism of the ark shell
, clams were exposed to different high temperatures (24, ...28 and 32 °C) for 72 h. The oxygen consumption and ammonia excretion rates were measured at 2, 12, 24, 48 and 72 h. The results indicated that the metabolic rates of the ark shell significantly increased with increasing heat stress, accompanied by mortalities in response to prolonged exposure. A metabolomics approach based on gas chromatography coupled with mass spectrometry was further applied to assess the changes of metabolites in the mantle of the ark shell at 32 °C. Moreover, multivariate and pathway analyses were conducted for the different metabolites. The results showed that the heat stress caused changes in energy metabolism, amino acid metabolism, osmotic regulation, carbohydrate metabolism and lipid metabolism through different metabolic pathways. These results are consistent with the significant changes of oxygen consumption rate and ammonia excretion rate. The present study contributes to the understanding of the impacts of heat stress on intertidal bivalves and elucidates the relationship between individual-level responses and underlying molecular metabolic dynamics.
•Serum ion and biochemical parameters were influenced by infection with C. irritans.•High level of protective immunity following poly-infection by C. irritans.•ACP and AKP may play crucial roles in ...the immune response against this disease.•Multiple infections enhance pompano's immunity while causing limited harm.
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To investigate the response of pompano fish (Trachinotus ovatus) to white spot disease, we used the protozoan Cryptocaryon irritans to infect live 450-g specimens at concentrations of 40,000 theronts/fish. We assessed the relative infection intensity (RII), serum immobilizing titer, and immunity-related enzyme activities (ACP, AKP, LZM), and assessed feeding, serum ion concentrations (Na+, Cl−, Ca2+ and K+) and blood biochemistry (ALT, AST, LDH) of pompano. The fish were then treated with a lethal dose of C. irritans (70,000 theronts/fish) and the number of deaths was recorded. We found that the relative infection intensities of the control group, group I, and group II were 0, 0.630 ± 0.179, and 0.014 ± 0.006. Poly-infection induced a significant increase in the serum immobilizing titer (853.33 ± 295.60) of group II. In terms of the biochemical assessment, group II had significantly higher alkaline phosphatase and acid phosphatase activities than the other groups, and the lowest lysozyme activity (P < 0.05), compared to higher activity in the control group and the highest level in group I. Only the fishes of group I had stopped feeding after treatment. The concentrations of Na+, Cl−, and Ca2+ in blood serum did not differ significantly among the three groups, but K+ concentration increased with the increasing infection frequency. Alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase activities in fish of group II were significantly higher than those of the other groups. Survival of the fish subjected to the lethal dose of C. irritans was 0, 0, and 100 in groups control, I, and II, respectively. In conclusions, based on the food intake of group II, along with the results of relative infection intensity, serum immobilizing titer, and survival, we speculate that the fish in that group acquired high protective immunity following poly-infection by C. irritans, experiencing limited harm for pompano.
Introduction
High rainfall and excessive urea application are counterproductive to summer maize growth requirements and lower grain yield and water/nitrogen (N) use efficiency. The objective of this ...study was to determine whether ETc irrigation based on summer maize demand and reduced nitrogen rate in the Huang Huai Hai Plain increased water and nitrogen use efficiency without sacrificing yield.
Methods
To achieve this, we conducted an experiment with four irrigation levels ambient rainfall (I0) and 50% (I1), 75% (I2), and 100% (I3) of actual crop evapotranspiration (ET
c
) and four nitrogen rates no nitrogen fertilizer (N0), recommended nitrogen rate of urea (NU), recommended nitrogen rate of blending controlled-release urea with conventional urea fertilizer (BCRF) (NC), and reduced nitrogen rate of BCRF (NR) in 2016–2018.
Results
The results show that reduced irrigation and nitrogen rate reduced Fv/Fm,
13
C-photosynthate, and nitrogen accumulation both in the kernel and plant. I3NC and I3NU accumulated higher
13
C-photosynthate, nitrogen, and dry matter. However,
13
C-photosynthate and nitrogen distribution to the kernel was decreased from I2 to I3 and was higher in BCRF than in urea. I2NC and I2NR promoted their distribution to the kernel, resulting in a higher harvest index. Compared with I3NU, I2NR increased root length density by 32.8% on average, maintaining considerable leaf Fv/Fm and obtaining similar kernel number and kernel weight. The higher root length density of I2NR of 40–60 cm promoted
13
C-photosynthate and nitrogen distribution to the kernel and increased the harvest index. As a result, the water use efficiency (WUE) and nitrogen agronomic use efficiency (NAUE) in I2NR increased by 20.5%–31.9% and 11.0%–38.0% than that in I3NU, respectively.
Discussion
Therefore, 75%ET
c
deficit irrigation and BCRF fertilizer with 80% nitrogen rate improved root length density, maintained leaf Fv/Fm in the milking stage, promoted 13C-photosynthate, and distributed nitrogen to the kernel, ultimately providing a higher WUE and NAUE without significantly reducing grain yield.
Cryptocaryon irritans is a type of marine ectoparasitic ciliate that infects teleost fishes. To illustrate the susceptibility and innate immune mechanism of fishes to C. irritans, four species of ...marine perciform fishes were selected in Fujian Province, a high-prevalence area of cryptocaryoniasis in China. The survival, diameter/number of tomonts, and infection ratio among Larimichthys crocea, Lateolabrax japonicus, Pagrus major, and Nibea albiflora were compared after artificial infection. Meanwhile, the immobilization titers of four fish species with no C. irritans infection were detected. Results showed that survival and serum immobilization titer of N. albiflora were significantly higher than those of the other three fish species. A strong negative linear correlation was found between the survival/serum immobilization titer and the mean tomont diameter. In addition, the smallest C. irritans infection ratio was found in N. albiflora, implying that the serum of fishes especially that of N. albiflora, inhibited the development of parasitic C. irritans cells, and the smallest tomont size was directly related to the number of infective theronts corresponding to the highest survival of fish. Moreover, complement activity inhibition assays suggested that the alternative complement pathway might play a major role in C. irritans resistance.
•Susceptibility and resistance of four marine perciform fishes to C. irritans infection.•N. albiflora has the strongest anti-C. irritans resistance among four fish species.•Alternative complement pathway of N. albiflora might play a major role in C. irritans resistance.
Pampus chinensis is a commercially important fishery species in the Indo-West Pacific region. In the present study, the genetic variation of P. chinensis among 10 sampling localities along the China ...coast and one from the Indonesia region was evaluated using mitochondrial DNA control region sequences. As a result, a total of 30 variable sites were detected in the 458 bp segment of the control region among 330 individuals from 11 localities, and 41 haplotypes were defined. Samples in the China coast present a high level of genetic diversity, with the values of haplotype diversity ranged from 0.674 to 0.860, and nucleotide diversity from 0.820% to 1.502%. Pairwise F
ST
statistics showed a moderate genetic divergence (−0.027 to 0.384) among samples from different geographical locations. Median-joining network analysis revealed a similar pattern of phylogeographic structure in samples from Ningbo and Dongxing although they were far apart. Therefore, joint influences of dispersal capability, spatial distance, ocean current and geographic segregation on the formation of the present population structure in P. chinensis was proposed. The results of the present study would be helpful for the sustainable utilization and management of this species.
The fish-gut microbiota play a key role in the physiology, development, and fitness of its host. An understanding of fish-gut microbial communities and the factors influencing community composition ...is crucial for improving fish performance. In this study, we compared the gut microbiota of juvenile black sea bream
among habitats: (1) wild, (2) offshore cage-culture, and (3) pond-culture. We also explored the relationships between the gut microbiota and host-associated environmental factors. Gut samples and associated environmental compartments were investigated using 16S rRNA gene sequencing. Our results revealed significant habitat-specific differences among the gut microbiota of juvenile
. Wild populations of juvenile
had more diverse gut microbiota than populations cultured in pond habitats due to their omnivorous feeding habits and the corresponding abundance of natural food resources. Significant variations in the composition, core taxa, and diversity of the microbiota were also found between the gut and the environmental compartments. However, no significant differences were observed among the microbiota of the environmental compartments in the relatively isolated pond habitat. Source tracking analysis recovered connections between the fish-gut microbiota and the diet, water and sediment environmental compartments. This connection was especially strong between the microbiota of the fish gut and that of the diet in the pond habitat: the diet microbiota accounted for 33.48 ± 0.21% of the gut microbiota. Results suggested that all
shared a core gut microbiota, regardless of differences in diet and habitat. However, environmental factors associated with both diet and habitat contributed to the significant differences between the gut microbiota of fish living in different habitats. To the authors' knowledge, this study presents the first comparison of gut microbiota among juvenile
with different diets and habitats. These findings enrich our understanding of the gut microbiota of
and help to clarify the interaction between gut microbiota and environmental factors. Our results may also help to guide and improve fish ecological fitness via the regulation of gut microbiota, thereby increasing the efficacy of stock enhancement programs for this species.
To determine the optimal larval density for hatchery culture of the clam
Meretrix meretrix, experiments with stocking densities of 5, 10, 20, 40 and 60 larvae ml
−
1
were designed, which included the ...developmental stages from D-veliger to 8 days post-settlement. Shell length, settlement time and survival rate of the larvae were recorded. Results showed that, at each sampling time, larvae reared at the highest density had the smallest mean size, whereas larvae reared at the lowest density had the largest mean size. Statistical differences in mean shell length at different stocking densities appeared from day 2, and greater differences occurred with increased culture time. Specific growth rate (SGR) in the rapid growing stage (day 0–3) was negatively correlated with density; however, no correlation was found between SGR and density in the slow growing stage (days 3–7). Settlement time was prolonged and shell length of settled larvae decreased as density increased. However, larval survival rate (74.8–79.1%) was independent of stocking density. Results showed that a high stocking density, in the designated range, is feasible for larval culture of the clam
M. meretrix. However, for large-scale culture, in the interest of costs and safety, a stocking density of 10–20 larvae ml
−
1
is recommended.
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