Current Articles
2025, Volume 47, Issue 9
Display Method:
2025,
47(9):
1-22.
doi: 10.12284/hyxb2025120
Abstract:
The Asian continental marginal seas are among the most representative “source-to-sink” coupled systems globally. Understanding their organic carbon (OC) burial processes under the context of Quaternary climate change is of great significance for unraveling the evolution of the global carbon cycle. This study provides a comprehensive review of the sources, burial flux variations, and driving mechanisms of OC in sediments from major Asian marginal seas. The results indicate that during glacial periods, most marginal seas exhibit increased OC content and burial fluxes. In many regions, total organic carbon (TOC) content, organic carbon isotopic composition (δ13Corg), and TOC/total nitrogen (TOC/TN) ratios display cyclic variations on orbital timescales. Mechanistically, sea-level changes regulate the process and intensity of terrigenous material delivery, monsoon systems influence watershed erosion and water column structure, while ocean currents and the distribution of oxygen minimum zones (OMZs) jointly control the spatial variability of carbon sink efficiency. Sedimentary records from representative sites suggest that increased terrigenous input, OMZ development, or higher sedimentation rates during glacials often enhance the preservation and burial of OC. However, in certain high-latitude or deep-water regions (e.g., the Sea of Okhotsk and the Sea of Japan), reduced marine productivity during glacials may lower OC burial efficiency. Furthermore, this study employs combined proxies such as δ13Corg and TOC/TN ratios to quantify the mixing characteristics and evolutionary history of different OC sources, and estimates of OC burial fluxes reveal the differential responses of regional carbon sinks to glacial–interglacial cycles. Despite significant progress, challenges remain in end-member construction, proxy standardization, and high-resolution spatiotemporal reconstructions. Future research should focus on cross-regional comparisons, coupled mechanistic modeling, and refined chronological controls. These efforts will enhance our understanding of the evolution of carbon sinks in Asian marginal seas and their geological roles in the global carbon cycle, contributing to more accurate predictions of oceanic carbon sink dynamics under future climate change scenarios.
The Asian continental marginal seas are among the most representative “source-to-sink” coupled systems globally. Understanding their organic carbon (OC) burial processes under the context of Quaternary climate change is of great significance for unraveling the evolution of the global carbon cycle. This study provides a comprehensive review of the sources, burial flux variations, and driving mechanisms of OC in sediments from major Asian marginal seas. The results indicate that during glacial periods, most marginal seas exhibit increased OC content and burial fluxes. In many regions, total organic carbon (TOC) content, organic carbon isotopic composition (δ13Corg), and TOC/total nitrogen (TOC/TN) ratios display cyclic variations on orbital timescales. Mechanistically, sea-level changes regulate the process and intensity of terrigenous material delivery, monsoon systems influence watershed erosion and water column structure, while ocean currents and the distribution of oxygen minimum zones (OMZs) jointly control the spatial variability of carbon sink efficiency. Sedimentary records from representative sites suggest that increased terrigenous input, OMZ development, or higher sedimentation rates during glacials often enhance the preservation and burial of OC. However, in certain high-latitude or deep-water regions (e.g., the Sea of Okhotsk and the Sea of Japan), reduced marine productivity during glacials may lower OC burial efficiency. Furthermore, this study employs combined proxies such as δ13Corg and TOC/TN ratios to quantify the mixing characteristics and evolutionary history of different OC sources, and estimates of OC burial fluxes reveal the differential responses of regional carbon sinks to glacial–interglacial cycles. Despite significant progress, challenges remain in end-member construction, proxy standardization, and high-resolution spatiotemporal reconstructions. Future research should focus on cross-regional comparisons, coupled mechanistic modeling, and refined chronological controls. These efforts will enhance our understanding of the evolution of carbon sinks in Asian marginal seas and their geological roles in the global carbon cycle, contributing to more accurate predictions of oceanic carbon sink dynamics under future climate change scenarios.
2025,
47(9):
23-42.
doi: 10.12284/hyxb2025108
Abstract:
Global warming and extreme thermal events have induced widespread coral bleaching, leading to the rapid degradation of coral reef ecosystems across the globe. Identifying functional genes associated with thermotolerance is crucial for elucidating coral adaptation mechanisms to climate warming and enabling scientific predictions regarding coral reef ecosystem trajectories. However, the current understanding of the molecular mechanism of coral holobiont in response to heat stress is very insufficient. Therefore, this paper reviews the research progress of functional genes related to coral thermal adaptation. Initially, pattern recognition receptors (PRRs), including Toll-like receptors (TLRs), play a crucial role in detecting heat stress and activating downstream signaling cascades, thereby initiating the immune response process. These responses primarily involve: upregulation of heat shock proteins (HSPs) to facilitate the refolding of denatured polypeptides; induction of antioxidant protein genes to mitigate oxidative damage caused by reactive oxygen species (ROS); genes associated with apoptosis and pyroptosis play a crucial role in eliminating “harmful” cells. As thermal stress intensifies, corals initiate a sophisticated network of cellular processes to maintain. As heat stress intensifies, corals initiate a series of complex processes to jointly maintain cellular homeostasis. This includes: rapid activation of photoprotective protein genes to repair the photosynthetic apparatus of Symbiodiniaceae; expression of host fluorescent proteins to maintain redox balance; calcium channel proteins maintain the stability of intracellular Ca2+ levels; modulation of metabolic pathways to ensure adequate nutrient supply; inhibition of cell cycle progression to conserve energy; maintenance of cytoskeletal integrity to preserve structural stability; and regulation of ubiquitin-proteasome system for protein quality control. Furthermore, recurrent thermal stress events can induce acclimatization in corals, potentially enhancing their thermal tolerance through multiple mechanisms: downregulation of host metabolic rate, protection of heat-sensitive proteins, and upregulation of antioxidant enzymes and ammonium assimilation pathways.
Global warming and extreme thermal events have induced widespread coral bleaching, leading to the rapid degradation of coral reef ecosystems across the globe. Identifying functional genes associated with thermotolerance is crucial for elucidating coral adaptation mechanisms to climate warming and enabling scientific predictions regarding coral reef ecosystem trajectories. However, the current understanding of the molecular mechanism of coral holobiont in response to heat stress is very insufficient. Therefore, this paper reviews the research progress of functional genes related to coral thermal adaptation. Initially, pattern recognition receptors (PRRs), including Toll-like receptors (TLRs), play a crucial role in detecting heat stress and activating downstream signaling cascades, thereby initiating the immune response process. These responses primarily involve: upregulation of heat shock proteins (HSPs) to facilitate the refolding of denatured polypeptides; induction of antioxidant protein genes to mitigate oxidative damage caused by reactive oxygen species (ROS); genes associated with apoptosis and pyroptosis play a crucial role in eliminating “harmful” cells. As thermal stress intensifies, corals initiate a sophisticated network of cellular processes to maintain. As heat stress intensifies, corals initiate a series of complex processes to jointly maintain cellular homeostasis. This includes: rapid activation of photoprotective protein genes to repair the photosynthetic apparatus of Symbiodiniaceae; expression of host fluorescent proteins to maintain redox balance; calcium channel proteins maintain the stability of intracellular Ca2+ levels; modulation of metabolic pathways to ensure adequate nutrient supply; inhibition of cell cycle progression to conserve energy; maintenance of cytoskeletal integrity to preserve structural stability; and regulation of ubiquitin-proteasome system for protein quality control. Furthermore, recurrent thermal stress events can induce acclimatization in corals, potentially enhancing their thermal tolerance through multiple mechanisms: downregulation of host metabolic rate, protection of heat-sensitive proteins, and upregulation of antioxidant enzymes and ammonium assimilation pathways.
2025,
47(9):
67-81.
doi: 10.12284/hyxb2025104
Abstract:
The coastal estuarine ecosystem is a unique ecosystem formed at the confluence of rivers and oceans. It has high primary productivity, can provide food and habitat for many organisms, and plays an important role in maintaining the stability of ecosystem structure. In order to explore the temporal and spatial dynamics of phytoplankton community and its environmental impact factors in Liuqing River Bay, four cruises were carried out at seven sampling sites in Liuqing River Bay in winter (March), spring (May), summer (August) and autumn (October) of 2023. The results showed that a total of 97 species of phytoplankton belonging to 56 genera and 3 phyla were identified in the four cruises. The phytoplankton community structure was mainly composed of diatoms and dinoflagellates. The cell abundance of phytoplankton in Liuqing River Bay has obvious temporal and spatial dynamic changes. From the time dimension, the average abundance of phytoplankton in the four seasons from high to low is winter, autumn, summer and spring. In terms of spatial distribution, the phytoplankton abundance in Liuqing River Bay reflects seasonal spatial distribution differences. The high abundance areas in spring, autumn and winter are concentrated in the northeast coastal waters, which are mainly driven by terrestrial input. The low abundance area is continuously distributed in the northwest sea area, which is mainly related to turbulent mixing. The overall spatial pattern is characterized by near-shore enrichment and offshore decline. Dominant species mainly include Bacillaria paradoxa, Coscinodiscus argus, Chaetoceros decipiens f. decipiens, Chaetoceros curvisetus, Coscinodiscus asteromphalus var. asteromphalus, Coscinodiscus granii of the phylum Bacillariophyta, and Ceratium macroceros, Ceratium tripos of the phylum Dinophyta. The biodiversity in summer and autumn was significantly higher than that in spring and winter. The results of redundancy analysis showed that salinity, DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphorus) were the key environmental factors affecting the changes of phytoplankton community structure.
The coastal estuarine ecosystem is a unique ecosystem formed at the confluence of rivers and oceans. It has high primary productivity, can provide food and habitat for many organisms, and plays an important role in maintaining the stability of ecosystem structure. In order to explore the temporal and spatial dynamics of phytoplankton community and its environmental impact factors in Liuqing River Bay, four cruises were carried out at seven sampling sites in Liuqing River Bay in winter (March), spring (May), summer (August) and autumn (October) of 2023. The results showed that a total of 97 species of phytoplankton belonging to 56 genera and 3 phyla were identified in the four cruises. The phytoplankton community structure was mainly composed of diatoms and dinoflagellates. The cell abundance of phytoplankton in Liuqing River Bay has obvious temporal and spatial dynamic changes. From the time dimension, the average abundance of phytoplankton in the four seasons from high to low is winter, autumn, summer and spring. In terms of spatial distribution, the phytoplankton abundance in Liuqing River Bay reflects seasonal spatial distribution differences. The high abundance areas in spring, autumn and winter are concentrated in the northeast coastal waters, which are mainly driven by terrestrial input. The low abundance area is continuously distributed in the northwest sea area, which is mainly related to turbulent mixing. The overall spatial pattern is characterized by near-shore enrichment and offshore decline. Dominant species mainly include Bacillaria paradoxa, Coscinodiscus argus, Chaetoceros decipiens f. decipiens, Chaetoceros curvisetus, Coscinodiscus asteromphalus var. asteromphalus, Coscinodiscus granii of the phylum Bacillariophyta, and Ceratium macroceros, Ceratium tripos of the phylum Dinophyta. The biodiversity in summer and autumn was significantly higher than that in spring and winter. The results of redundancy analysis showed that salinity, DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphorus) were the key environmental factors affecting the changes of phytoplankton community structure.
2025,
47(9):
82-90.
doi: 10.12284/hyxb2025092
Abstract:
This study is based on survey data of fish communities in the Zhoushan fishing ground and uses a resampling technique to simulate the random loss of rare and common species. It also employs a biomass proportion reduction method to simulate scenarios of biomass loss, in order to explore the mechanisms by which the loss of different ecological groups affects functional diversity in fish communities. The results show that although rare species account for only 3% of the total community biomass, their species richness constitutes nearly 40% of the community, indicating an important ecological niche within the community structure. The simulation of species loss scenarios revealed that the loss of rare species’ richness directly impacts the functional diversity indices, specifically leading to a decrease in functional richness and an increase in functional evenness, while functional divergence and Rao’s quadratic entropy indices showed no significant changes. In contrast, the loss of common species’ richness resulted in a decline in functional richness, while the other three functional diversity indices remained relatively stable. Under the biomass loss scenarios, the reduction in rare species’ biomass led to unchanged functional richness but declines in functional evenness, functional divergence, and Rao’s quadratic entropy indices. The functional evenness index exhibited a nonlinear decline that started slowly and then accelerated, while the other two indices showed linear decreasing patterns. In contrast, the loss of common species’ biomass caused the latter three indices to decline in a pattern that started rapidly and then slowed down. Rare species occupy unique functional niches in the community, with their functional traits distributed at the edges of the multidimensional functional space. They play a unique role in maintaining community functional diversity. Strengthening the protection of rare species and their habitats is a key strategy for maintaining regional ecosystem diversity and stability.
This study is based on survey data of fish communities in the Zhoushan fishing ground and uses a resampling technique to simulate the random loss of rare and common species. It also employs a biomass proportion reduction method to simulate scenarios of biomass loss, in order to explore the mechanisms by which the loss of different ecological groups affects functional diversity in fish communities. The results show that although rare species account for only 3% of the total community biomass, their species richness constitutes nearly 40% of the community, indicating an important ecological niche within the community structure. The simulation of species loss scenarios revealed that the loss of rare species’ richness directly impacts the functional diversity indices, specifically leading to a decrease in functional richness and an increase in functional evenness, while functional divergence and Rao’s quadratic entropy indices showed no significant changes. In contrast, the loss of common species’ richness resulted in a decline in functional richness, while the other three functional diversity indices remained relatively stable. Under the biomass loss scenarios, the reduction in rare species’ biomass led to unchanged functional richness but declines in functional evenness, functional divergence, and Rao’s quadratic entropy indices. The functional evenness index exhibited a nonlinear decline that started slowly and then accelerated, while the other two indices showed linear decreasing patterns. In contrast, the loss of common species’ biomass caused the latter three indices to decline in a pattern that started rapidly and then slowed down. Rare species occupy unique functional niches in the community, with their functional traits distributed at the edges of the multidimensional functional space. They play a unique role in maintaining community functional diversity. Strengthening the protection of rare species and their habitats is a key strategy for maintaining regional ecosystem diversity and stability.
2025,
47(9):
91-100.
doi: 10.12284/hyxb2025098
Abstract:
Nearshore coral reefs are frequently subjected to prolonged exposure to high levels of suspended particulate matter (SPM). However, the tolerance threshold of scleractinian corals to SPM remains inadequatedly understood, complicating the protection and management of nearshore scleractinian coral communities. In this study, we investigated the physiological responses of Dipsastraea speciosa and Cyphastrea sp., the dominant species of scleractinian corals in the Dongshan waters, which represent the northern distribution limit of scleractinian coral communities, under varying SPM mass concentrations (0 mg/L, 35 mg/L, 50 mg/L and 100 mg/L). A SPM-controlled simulated system was employed by injecting SPM into experimental tanks to regulate its concentration over a 28-day period. Morphological characteristics and a series of photosynthetic physiological parameters were used as indicators. The results indicated that the polyps of both coral species exposed to three groups of SPM treatments exhibited shrinkageduring the initial stages of the experiment, but quickly recovered over time. No individual of coral bleaching or mortality were observed. Additionally, both coral species demonstrated significant photosynthetic physiological plasticity, evidenced by rising ΦPSⅡ values with SPM mass concentration increased, reaching a maximum at 100 mg/L. This suggests that the two coral species can mitigate light shading by enhancing their photosynthetic efficiency in response to high SPM mass concentrations. Furthermore, Fv/Fm ratios, chlorophyll content, and zooxanthella density for both coral species remained relatively stable under high SPM exposure, indicating that their photosynthetic performance remained healthy despite elevated SPM levels. This implies that the tolerance threshold for SPM mass concentration of these two scleractinian corals to SPM may exceed 100 mg/L. This study is the first experiment in China to successfully maintain high SPM levels over an extended period, and the findings provide essential data for the protection and management of scleractinian coral communities in China.
Nearshore coral reefs are frequently subjected to prolonged exposure to high levels of suspended particulate matter (SPM). However, the tolerance threshold of scleractinian corals to SPM remains inadequatedly understood, complicating the protection and management of nearshore scleractinian coral communities. In this study, we investigated the physiological responses of Dipsastraea speciosa and Cyphastrea sp., the dominant species of scleractinian corals in the Dongshan waters, which represent the northern distribution limit of scleractinian coral communities, under varying SPM mass concentrations (0 mg/L, 35 mg/L, 50 mg/L and 100 mg/L). A SPM-controlled simulated system was employed by injecting SPM into experimental tanks to regulate its concentration over a 28-day period. Morphological characteristics and a series of photosynthetic physiological parameters were used as indicators. The results indicated that the polyps of both coral species exposed to three groups of SPM treatments exhibited shrinkageduring the initial stages of the experiment, but quickly recovered over time. No individual of coral bleaching or mortality were observed. Additionally, both coral species demonstrated significant photosynthetic physiological plasticity, evidenced by rising ΦPSⅡ values with SPM mass concentration increased, reaching a maximum at 100 mg/L. This suggests that the two coral species can mitigate light shading by enhancing their photosynthetic efficiency in response to high SPM mass concentrations. Furthermore, Fv/Fm ratios, chlorophyll content, and zooxanthella density for both coral species remained relatively stable under high SPM exposure, indicating that their photosynthetic performance remained healthy despite elevated SPM levels. This implies that the tolerance threshold for SPM mass concentration of these two scleractinian corals to SPM may exceed 100 mg/L. This study is the first experiment in China to successfully maintain high SPM levels over an extended period, and the findings provide essential data for the protection and management of scleractinian coral communities in China.
2025,
47(9):
101-114.
doi: 10.12284/hyxb2025100
Abstract:
Symbiodiniaceae are indispensable partners in the coral symbiotic system, and different species exhibit varying sensitivities to environmental stress, thereby influencing the environmental adaptability of their coral hosts. This study investigates the stress response patterns of two widely distributed coral symbiotic Symbiodiniaceae species—environmentally sensitive Cladocopium goreaui and environmentally tolerant Durusdinium trenchii—under heat stress from the perspective of lipid metabolism. The results showed that heat stress significantly affected their cell density, photosynthetic pigment content, photochemical efficiency of photosystem Ⅱ (Fv/Fm), and antioxidant activity, with statistically significant differences (P < 0.05). Lipidomics revealed that lipid-differentiated metabolites such as phosphatidylcholine, triglycerides, phosphatidylethanolamine and lysophosphatidylcholine were significantly enriched in glycerophospholipid metabolism, triglyceride metabolism, and polyunsaturated fatty acid-related metabolic pathways in response to heat stress in C. goreaui and D. trenchii. Notably, the two species exhibited significant differences in sphingolipid metabolism: D. trenchii downregulated ceramide levels to reduce oxidative stress damage, regulate autophagy, and adapt to changes in membrane fluidity, whereas C. goreaui primarily upregulated lipid molecules rich in polyunsaturated fatty acids to maintain membrane stability and regulate signal transduction. A deeper understanding of the lipid metabolic stress response mechanisms of Symbiodiniaceae with different environmental sensitivities under heat stress provides new insights into enhancing coral adaptability to environmental changes from a symbiotic partner perspective.
Symbiodiniaceae are indispensable partners in the coral symbiotic system, and different species exhibit varying sensitivities to environmental stress, thereby influencing the environmental adaptability of their coral hosts. This study investigates the stress response patterns of two widely distributed coral symbiotic Symbiodiniaceae species—environmentally sensitive Cladocopium goreaui and environmentally tolerant Durusdinium trenchii—under heat stress from the perspective of lipid metabolism. The results showed that heat stress significantly affected their cell density, photosynthetic pigment content, photochemical efficiency of photosystem Ⅱ (Fv/Fm), and antioxidant activity, with statistically significant differences (P < 0.05). Lipidomics revealed that lipid-differentiated metabolites such as phosphatidylcholine, triglycerides, phosphatidylethanolamine and lysophosphatidylcholine were significantly enriched in glycerophospholipid metabolism, triglyceride metabolism, and polyunsaturated fatty acid-related metabolic pathways in response to heat stress in C. goreaui and D. trenchii. Notably, the two species exhibited significant differences in sphingolipid metabolism: D. trenchii downregulated ceramide levels to reduce oxidative stress damage, regulate autophagy, and adapt to changes in membrane fluidity, whereas C. goreaui primarily upregulated lipid molecules rich in polyunsaturated fatty acids to maintain membrane stability and regulate signal transduction. A deeper understanding of the lipid metabolic stress response mechanisms of Symbiodiniaceae with different environmental sensitivities under heat stress provides new insights into enhancing coral adaptability to environmental changes from a symbiotic partner perspective.
2025,
47(9):
115-128.
doi: 10.12284/hyxb2025106
Abstract:
To evaluate the toxicological effects of polystyrene microplastics (PS-MPs) on the intestinal health of Sebastiscus marmoratus, individuals were exposed to PS-MP solutions at concentrations of 0, 1, and 10 mg/L for 21 days. A combination of analytical approaches, including enrichment analysis, histological examination, transcriptomic profiling, and 16S rRNA gene sequencing, was employed to assess alterations in intestinal morphology, gene expression, and microbial community composition. The results demonstrated a time-dependent accumulation of PS-MPs in the intestines, with mass fraction reaching 16.20 × 10–6 (μg/g) by day 7. Histopathological analysis revealed dose-dependent intestinal damage: at 1 mg/L, necrosis, detachment, and vacuolar degeneration of mucosal cells were observed; at 10 mg/L, severe villus atrophy, necrosis, vacuolization, and significant reductions in intestinal wall thickness, muscle layer thickness, and villus length and width were evident. Transcriptomic analysis identified 313 and 169 differentially expressed genes (DEGs) after 7 and 21 days of exposure, respectively. KEGG pathway enrichment revealed that DEGs at day 7 were primarily involved in the p53 signaling pathway, starch and sucrose metabolism, and Toll-like receptor signaling pathway. By day 21, enrichment was observed in pathways related to steroid biosynthesis, arachidonic acid metabolism, and NOD-like receptor signaling pathway. Although no significant changes in microbial composition were detected at the phylum level, notable increases in the relative abundances of Fusobacteriaceae, Vibrionaceae at the family level and Cetobacterium, Prevotella at the genus level were observed, potentially indicating enhanced intestinal barrier repair and anti-inflammatory responses. In conclusion, PS-MP exposure resulted in structural damage to intestinal tissues, disruption of the mucosal barrier, and inflammatory responses in S. marmoratus, ultimately compromising organismal health.
To evaluate the toxicological effects of polystyrene microplastics (PS-MPs) on the intestinal health of Sebastiscus marmoratus, individuals were exposed to PS-MP solutions at concentrations of 0, 1, and 10 mg/L for 21 days. A combination of analytical approaches, including enrichment analysis, histological examination, transcriptomic profiling, and 16S rRNA gene sequencing, was employed to assess alterations in intestinal morphology, gene expression, and microbial community composition. The results demonstrated a time-dependent accumulation of PS-MPs in the intestines, with mass fraction reaching 16.20 × 10–6 (μg/g) by day 7. Histopathological analysis revealed dose-dependent intestinal damage: at 1 mg/L, necrosis, detachment, and vacuolar degeneration of mucosal cells were observed; at 10 mg/L, severe villus atrophy, necrosis, vacuolization, and significant reductions in intestinal wall thickness, muscle layer thickness, and villus length and width were evident. Transcriptomic analysis identified 313 and 169 differentially expressed genes (DEGs) after 7 and 21 days of exposure, respectively. KEGG pathway enrichment revealed that DEGs at day 7 were primarily involved in the p53 signaling pathway, starch and sucrose metabolism, and Toll-like receptor signaling pathway. By day 21, enrichment was observed in pathways related to steroid biosynthesis, arachidonic acid metabolism, and NOD-like receptor signaling pathway. Although no significant changes in microbial composition were detected at the phylum level, notable increases in the relative abundances of Fusobacteriaceae, Vibrionaceae at the family level and Cetobacterium, Prevotella at the genus level were observed, potentially indicating enhanced intestinal barrier repair and anti-inflammatory responses. In conclusion, PS-MP exposure resulted in structural damage to intestinal tissues, disruption of the mucosal barrier, and inflammatory responses in S. marmoratus, ultimately compromising organismal health.
2025,
47(9):
129-144.
doi: 10.12284/hyxb2025110
Abstract:
Anchisquilla fasciata belongs to the Squillidae (Latreille, 1802). In this study, the complete mitochondrial genome of Anchisquilla fasciata was obtained through next-generation sequencing technology. Analysis of the basic structural characteristics of the genome revealed that it contains a total of 37 genes, including 13 protein-coding genes (PCGs), 2 rRNA genes, and 22 tRNA genes. Analysis of nucleotide composition showed that A had the highest content at 35.42%, while G had the lowest content at 12.83%. Selection pressure analysis was conducted on the mitochondrial genomes of 11 species within the Squillidae, and it was found that all PCGs were under purifying selection. Additionally, a phylogenetic tree was constructed using the 13 PCGs of mitochondrial genomes from two subclasses of Malacostraca, revealing that the Squillidae forms a monophyletic group with species within the family branching off into a distinct clade, showing clear differentiation from other related Hoplocarida (such as the Lysiosquillidae). Comparison of mitochondrial gene rearrangements within Malacostraca showed that the Stomatopoda did not exhibit any rearrangements. The reconstructed chronogram of divergence times within the Hoplocarida indicated that the earliest diversification of existing species occurred during the Cretaceous period of the Mesozoic era, with a significant diversification of species in the Cenozoic era. These results will provide better insights into the phylogenetic relationships among different species of Squillidae and the evolutionary positions and relationships among subclasses within Malacostraca.
Anchisquilla fasciata belongs to the Squillidae (Latreille, 1802). In this study, the complete mitochondrial genome of Anchisquilla fasciata was obtained through next-generation sequencing technology. Analysis of the basic structural characteristics of the genome revealed that it contains a total of 37 genes, including 13 protein-coding genes (PCGs), 2 rRNA genes, and 22 tRNA genes. Analysis of nucleotide composition showed that A had the highest content at 35.42%, while G had the lowest content at 12.83%. Selection pressure analysis was conducted on the mitochondrial genomes of 11 species within the Squillidae, and it was found that all PCGs were under purifying selection. Additionally, a phylogenetic tree was constructed using the 13 PCGs of mitochondrial genomes from two subclasses of Malacostraca, revealing that the Squillidae forms a monophyletic group with species within the family branching off into a distinct clade, showing clear differentiation from other related Hoplocarida (such as the Lysiosquillidae). Comparison of mitochondrial gene rearrangements within Malacostraca showed that the Stomatopoda did not exhibit any rearrangements. The reconstructed chronogram of divergence times within the Hoplocarida indicated that the earliest diversification of existing species occurred during the Cretaceous period of the Mesozoic era, with a significant diversification of species in the Cenozoic era. These results will provide better insights into the phylogenetic relationships among different species of Squillidae and the evolutionary positions and relationships among subclasses within Malacostraca.
2025,
47(9):
145-154.
doi: 10.12284/hyxb2025102
Abstract:
Calcium carbonate (CaCO3), as a major component of shells, interacts with the organic matter framework to form shells and provide protection for mollusks. Ca2+ is an important component of CaCO3, and its acquisition, transport, and precipitation processes can significantly affect calcium carbonate deposition in mollusks. However, there is still a lack of clarity regarding the process of calcium carbonate deposition and mechanism of related genes in forming shells. Calmodulin (CaM) is a protein widely found in eukaryotic cells and specifically binds to Ca2+, which is mainly involved in a variety of physiological processes such as cellular signal transduction, regulation of target enzyme activities and regulation of Ca2+ homeostasis. In order to investigate the relationship between CaM gene and calcium carbonate deposition in shells, we performed molecular identification and expression characterization of CaM gene in Sinonovacula constricta (ScCaM), and investigated the Ca2+-binding activity of the recombinant protein ScCaM and its role in calcium carbonate deposition. The results showed that the ScCaM gene encoded a total of 149 amino acids and contained four consecutive EF-hand structural domains. ScCaM was expressed in all tissues, with the expression level in gill and mantle tissues being significantly higher than in foot, siphon, adductor muscle and hepatopancreas tissues (P < 0.05). Furthermore, the content of calcium carbonate in shells was positively proportional to their shell weight. Meanwhile, individuals with larger shell weights had higher expression levels of ScCaM. ScCaM recombinant protein had calcium ion binding activity, which can accelerate the rate of calcium carbonate deposition, and the promotion effect showed an obvious protein concentration dependence. The results showed that ScCaM gene/protein expression was closely related to shell calcium carbonate content: elevated ScCaM gene/protein expression could enhance Ca2+ transport efficiency, promote shell calcium carbonate deposition, and thus increase shell weight. This study preliminarily investigated the role of ScCaM gene in shell calcium carbonate deposition, and provided a theoretical basis for analyzing the molecular mechanism of shell formation in S. constricta.
Calcium carbonate (CaCO3), as a major component of shells, interacts with the organic matter framework to form shells and provide protection for mollusks. Ca2+ is an important component of CaCO3, and its acquisition, transport, and precipitation processes can significantly affect calcium carbonate deposition in mollusks. However, there is still a lack of clarity regarding the process of calcium carbonate deposition and mechanism of related genes in forming shells. Calmodulin (CaM) is a protein widely found in eukaryotic cells and specifically binds to Ca2+, which is mainly involved in a variety of physiological processes such as cellular signal transduction, regulation of target enzyme activities and regulation of Ca2+ homeostasis. In order to investigate the relationship between CaM gene and calcium carbonate deposition in shells, we performed molecular identification and expression characterization of CaM gene in Sinonovacula constricta (ScCaM), and investigated the Ca2+-binding activity of the recombinant protein ScCaM and its role in calcium carbonate deposition. The results showed that the ScCaM gene encoded a total of 149 amino acids and contained four consecutive EF-hand structural domains. ScCaM was expressed in all tissues, with the expression level in gill and mantle tissues being significantly higher than in foot, siphon, adductor muscle and hepatopancreas tissues (P < 0.05). Furthermore, the content of calcium carbonate in shells was positively proportional to their shell weight. Meanwhile, individuals with larger shell weights had higher expression levels of ScCaM. ScCaM recombinant protein had calcium ion binding activity, which can accelerate the rate of calcium carbonate deposition, and the promotion effect showed an obvious protein concentration dependence. The results showed that ScCaM gene/protein expression was closely related to shell calcium carbonate content: elevated ScCaM gene/protein expression could enhance Ca2+ transport efficiency, promote shell calcium carbonate deposition, and thus increase shell weight. This study preliminarily investigated the role of ScCaM gene in shell calcium carbonate deposition, and provided a theoretical basis for analyzing the molecular mechanism of shell formation in S. constricta.
2025,
47(9):
43-54.
doi: 10.12284/hyxb2025094
Abstract:
Stable carbon isotope (δ13C) and nitrogen isotope (δ15N) compositions are powerful tools for elucidating fish physiology, trophic interactions, and origin. However, pretreatment methods can substantially influence isotopic results, and the underlying mechanisms remain poorly understood. This study investigates the effects of lipid removal from muscle and acid leaching of scales on the δ13C and δ15N values of large yellow croaker (Larimichthys crocea), a major mariculture species in China. We found that lipid extraction significantly increased muscle δ13C, while acid leaching decreased scale δ13C. An isotope mixing model effectively explained these δ13C variations. Conversely, both pretreatments increased δ15N, suggesting potential losses of specific nitrogen isotope signals. Utilizing a dynamic equilibrium model, we established a theoretical relationship between carbon and nitrogen isotopes in muscle and scales, validating scales as a muscle proxy for nitrogen isotope analysis. This research provides critical baseline data for understanding stable isotope heterogeneity in large yellow croaker, contributes to our understanding of inter-tissue metabolic dynamics, and supports the application of non-lethal sampling in fish stable isotope studies.
Stable carbon isotope (δ13C) and nitrogen isotope (δ15N) compositions are powerful tools for elucidating fish physiology, trophic interactions, and origin. However, pretreatment methods can substantially influence isotopic results, and the underlying mechanisms remain poorly understood. This study investigates the effects of lipid removal from muscle and acid leaching of scales on the δ13C and δ15N values of large yellow croaker (Larimichthys crocea), a major mariculture species in China. We found that lipid extraction significantly increased muscle δ13C, while acid leaching decreased scale δ13C. An isotope mixing model effectively explained these δ13C variations. Conversely, both pretreatments increased δ15N, suggesting potential losses of specific nitrogen isotope signals. Utilizing a dynamic equilibrium model, we established a theoretical relationship between carbon and nitrogen isotopes in muscle and scales, validating scales as a muscle proxy for nitrogen isotope analysis. This research provides critical baseline data for understanding stable isotope heterogeneity in large yellow croaker, contributes to our understanding of inter-tissue metabolic dynamics, and supports the application of non-lethal sampling in fish stable isotope studies.
2025,
47(9):
55-66.
doi: 10.12284/hyxb2025096
Abstract:
A self-developed separation and enrichment device was employed to investigate the pretreatment method for isolating and concentrating 15 trace elements (Al, Sc, V, Fe, Co, Ni, Cu, Zn, Ga, Cd, Nd, Pb, Bi, Th, and U) from seawater using Toyopearl AF-Chelate 650M chelating resin. Key parameters including sample loading pH, washing solution composition and volume, and eluent type and volume were optimized. High-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) was used for accurate determination. The results demonstrated that when 8.92 mL of seawater sample was mixed with acetic acid-ammonium acetate buffer solution at a 1:1 ratio (loading pH = 5.25) and loaded onto the resin, matrix impurities could be effectively removed by washing with 8.0 mL of Milli-Q water. After matrix removal, the adsorbed trace elements were quantitatively recovered by elution with 2.25 mL of 0.8 mol/L HNO3. Rh was added as an internal standard to the eluent prior to HR-ICP-MS analysis. Method blanks ranged from 0.27 pg (Cd) to 52.5 pg (Al), with method detection limits between 0.06 ng/L (Cd) and 1.67 ng/L (Zn). Excellent linearity (R2 > 0.999) was achieved across the concentration range of 0.01−50.0 μg/L. The method was validated using certified reference materials GBW(E)080040 and CASS-6. For GBW(E)080040, measured mass concentrations of Cu, Zn, Cd and Pb agreed well with certified values (relative error < 4.1%, RSD < 4.1%), with spike recoveries of 92.6%−107% for all 15 elements. Results for CASS-6 also showed good agreement with certified and reported values (RSD < 6.4%). This method features simple and rapid pretreatment, efficient matrix removal, low detection limits, high accuracy and good precision, making it suitable for simultaneous determination of 15 trace elements in various water matrices including natural freshwater, drinking water, estuarine and marine waters.
A self-developed separation and enrichment device was employed to investigate the pretreatment method for isolating and concentrating 15 trace elements (Al, Sc, V, Fe, Co, Ni, Cu, Zn, Ga, Cd, Nd, Pb, Bi, Th, and U) from seawater using Toyopearl AF-Chelate 650M chelating resin. Key parameters including sample loading pH, washing solution composition and volume, and eluent type and volume were optimized. High-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) was used for accurate determination. The results demonstrated that when 8.92 mL of seawater sample was mixed with acetic acid-ammonium acetate buffer solution at a 1:1 ratio (loading pH = 5.25) and loaded onto the resin, matrix impurities could be effectively removed by washing with 8.0 mL of Milli-Q water. After matrix removal, the adsorbed trace elements were quantitatively recovered by elution with 2.25 mL of 0.8 mol/L HNO3. Rh was added as an internal standard to the eluent prior to HR-ICP-MS analysis. Method blanks ranged from 0.27 pg (Cd) to 52.5 pg (Al), with method detection limits between 0.06 ng/L (Cd) and 1.67 ng/L (Zn). Excellent linearity (R2 > 0.999) was achieved across the concentration range of 0.01−50.0 μg/L. The method was validated using certified reference materials GBW(E)080040 and CASS-6. For GBW(E)080040, measured mass concentrations of Cu, Zn, Cd and Pb agreed well with certified values (relative error < 4.1%, RSD < 4.1%), with spike recoveries of 92.6%−107% for all 15 elements. Results for CASS-6 also showed good agreement with certified and reported values (RSD < 6.4%). This method features simple and rapid pretreatment, efficient matrix removal, low detection limits, high accuracy and good precision, making it suitable for simultaneous determination of 15 trace elements in various water matrices including natural freshwater, drinking water, estuarine and marine waters.
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