ABSTRACT: The aim of this study was to understand the relationship between acoustic characteristics and body size of Korean rockfish Sebastes schlegelii in order to better estimate the body length of S. schlegelii by passive acoustic techniques. In this study, S. schlegelii, with a body length ranging from 21.7 to 24.8 cm (mean ± SD = 23.33 ± 0.93 cm) and a body weight of 144.2 to 250.3 g were selected as subjects. The aim was to explore the relationship between the acoustic characteristics of the fish and their standardized lengths through aquarium experiments. The vocalization frequency exhibited a main peak at around 150 Hz, a sub-peak at approximately 100 Hz, and the primary vocalization band extended from 100 to 350 Hz, with a pulse duration of 15.2 ± 2.4 ms. The results indicated that the peak frequency was negatively correlated with the standardized length, swim bladder length, width, and height (p <0.001). This research contributes to the understanding of the relationship between acoustic properties and body size and suggests the potential utility of passive acoustic monitoring techniques for estimating the body lengths of target species.
{"title":"Sound properties produced by Korean rockfish Sebastes schlegelii in relation to body and swim bladder size","authors":"Mingyuan Song, Binbin Xing, Dehua Gong, Xiaojie Cui, Leiming Yin, Mingzhi Li","doi":"10.3354/ab00771","DOIUrl":"https://doi.org/10.3354/ab00771","url":null,"abstract":"ABSTRACT: The aim of this study was to understand the relationship between acoustic characteristics and body size of Korean rockfish <i>Sebastes schlegelii</i> in order to better estimate the body length of <i>S. schlegelii</i> by passive acoustic techniques. In this study, <i>S. schlegelii</i>, with a body length ranging from 21.7 to 24.8 cm (mean ± SD = 23.33 ± 0.93 cm) and a body weight of 144.2 to 250.3 g were selected as subjects. The aim was to explore the relationship between the acoustic characteristics of the fish and their standardized lengths through aquarium experiments. The vocalization frequency exhibited a main peak at around 150 Hz, a sub-peak at approximately 100 Hz, and the primary vocalization band extended from 100 to 350 Hz, with a pulse duration of 15.2 ± 2.4 ms. The results indicated that the peak frequency was negatively correlated with the standardized length, swim bladder length, width, and height (p <0.001). This research contributes to the understanding of the relationship between acoustic properties and body size and suggests the potential utility of passive acoustic monitoring techniques for estimating the body lengths of target species.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT: Polysaccharides exhibit a multitude of biological activities, including antioxidant, antitumor, immunoregulatory, hepatoprotective, and anti-inflammatory effects, but it is not known whether such effects occur in fish. Head kidney macrophages from turbot Scophthalmus maximus L. were isolated and cultured to examine the responsiveness to natural polysaccharides as potential immune stimulators. Polysaccharides used in the research included Echinacea purpurea polysaccharide (EPP), Astragalus polysaccharide (APS), lentinan (LNT), seaweed polysaccharide (SPS), and laminarin (LAM). The test compounds were added to the cultures and assessed for their effects on the growth and immunomodulatory functions of the cells. Based on the results of cell activity, reactive oxygen species, and nitic oxide assays, APS was selected as an immune stimulator. After addition of APS to the culture medium, a comprehensive proteomic analysis was conducted to identify signaling pathways responsible for the immune effects on macrophages. Specific immune pathway proteins were upregulated in cells in response to the addition of APS, including macrophage migration inhibitory factor, myosin-α, metalloproteinase inhibitor, and collagenase type III. In particular, compared with non-stimulated cells, the expression level of the TLR22 receptor was significantly increased in stimulated macrophages (p < 0.01). A KEGG pathway analysis indicated that relevant pathways were activated, including TNF, PI3K-Akt, and NF-κB signaling pathways. ELISA and qRT-PCR analysis also indicated that APS reduced IL-1β and TNF-α levels in the cells following lipopolysaccharide (LPS) stimulation. These data suggest that APS produced an immunoprotective effect on the head kidney macrophages of turbot at 800 µg ml-1, and enhanced cell proliferation. Our results provide evidence for anti-inflammatory properties of APS. As such, APS could be a candidate immunopotentiating agent for fish.
{"title":"Effects of polysaccharides on turbot Scophthalmus maximus: evaluation with a head kidney macrophage cellular model","authors":"Xu-Feng Dong#, Xiao-Xue Wang#, Zhi-Hua Qin","doi":"10.3354/ab00770","DOIUrl":"https://doi.org/10.3354/ab00770","url":null,"abstract":"ABSTRACT: Polysaccharides exhibit a multitude of biological activities, including antioxidant, antitumor, immunoregulatory, hepatoprotective, and anti-inflammatory effects, but it is not known whether such effects occur in fish. Head kidney macrophages from turbot <i>Scophthalmus maximus</i> L. were isolated and cultured to examine the responsiveness to natural polysaccharides as potential immune stimulators. Polysaccharides used in the research included <i>Echinacea purpurea</i> polysaccharide (EPP), <i>Astragalus</i> polysaccharide (APS), lentinan (LNT), seaweed polysaccharide (SPS), and laminarin (LAM). The test compounds were added to the cultures and assessed for their effects on the growth and immunomodulatory functions of the cells. Based on the results of cell activity, reactive oxygen species, and nitic oxide assays, APS was selected as an immune stimulator. After addition of APS to the culture medium, a comprehensive proteomic analysis was conducted to identify signaling pathways responsible for the immune effects on macrophages. Specific immune pathway proteins were upregulated in cells in response to the addition of APS, including macrophage migration inhibitory factor, myosin-α, metalloproteinase inhibitor, and collagenase type III. In particular, compared with non-stimulated cells, the expression level of the TLR22 receptor was significantly increased in stimulated macrophages (p < 0.01). A KEGG pathway analysis indicated that relevant pathways were activated, including TNF, PI3K-Akt, and NF-κB signaling pathways. ELISA and qRT-PCR analysis also indicated that APS reduced IL-1β and TNF-α levels in the cells following lipopolysaccharide (LPS) stimulation. These data suggest that APS produced an immunoprotective effect on the head kidney macrophages of turbot at 800 µg ml<sup>-1</sup>, and enhanced cell proliferation. Our results provide evidence for anti-inflammatory properties of APS. As such, APS could be a candidate immunopotentiating agent for fish.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142200585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT: Photosymbioses, in which photosynthetic microorganisms reside within heterotrophic hosts, are important components of aquatic ecosystems and are under threat from environmental warming. The immediate ecological consequences of acute warming for archetypal photosymbioses, such as those between corals and zooxanthellae, are well documented. In contrast, understanding of the evolutionary responses of photosymbioses to persistent warming remains limited and direct observations of evolution in response to warming are scarce, as many associations are slow-evolving and do not enable observations on a tractable timescale. To address this knowledge gap, we exposed the widespread microbial Paramecium bursaria-Chlorella spp. photosymbiosis to 295 d of continuous growth under +5°°C of persistent warming. We subsequently quantified the thermal responses of traits associated with symbiosis persistence and ecological function (growth rate, symbiont density [the number of symbionts within hosts], and metabolic rates) compared with cultures maintained at ambient temperature and cultures exposed to -5°°C of cooling for the same time period. Strikingly, while growth rate thermal optimum increased with warming, net photosynthesis and carbon-use efficiency (the proportion of photosynthetic carbon available for growth) both strongly declined to zero. These data suggest a significant change in ecological function with persistent warming. We also detected larger autonomous symbiont populations following 295 d of warming, and symbionts from the warm-adapted symbiosis demonstrated a ‘switch’ from exclusive growth on organic to inorganic nitrogen, suggesting that symbionts could have evolved increased autonomy from hosts. Thus, warming could erode the ecological function and promote symbiont autonomy in photosymbiosis over evolutionary timescales.
{"title":"One year of warming leads to the total loss of productivity in a widespread photosymbiosis","authors":"B. Makin, C. D. Lowe","doi":"10.3354/ab00769","DOIUrl":"https://doi.org/10.3354/ab00769","url":null,"abstract":"ABSTRACT: Photosymbioses, in which photosynthetic microorganisms reside within heterotrophic hosts, are important components of aquatic ecosystems and are under threat from environmental warming. The immediate ecological consequences of acute warming for archetypal photosymbioses, such as those between corals and zooxanthellae, are well documented. In contrast, understanding of the evolutionary responses of photosymbioses to persistent warming remains limited and direct observations of evolution in response to warming are scarce, as many associations are slow-evolving and do not enable observations on a tractable timescale. To address this knowledge gap, we exposed the widespread microbial <i>Paramecium bursaria-Chlorella </i>spp. photosymbiosis to 295 d of continuous growth under +5°°C of persistent warming. We subsequently quantified the thermal responses of traits associated with symbiosis persistence and ecological function (growth rate, symbiont density [the number of symbionts within hosts], and metabolic rates) compared with cultures maintained at ambient temperature and cultures exposed to -5°°C of cooling for the same time period. Strikingly, while growth rate thermal optimum increased with warming, net photosynthesis and carbon-use efficiency (the proportion of photosynthetic carbon available for growth) both strongly declined to zero. These data suggest a significant change in ecological function with persistent warming. We also detected larger autonomous symbiont populations following 295 d of warming, and symbionts from the warm-adapted symbiosis demonstrated a ‘switch’ from exclusive growth on organic to inorganic nitrogen, suggesting that symbionts could have evolved increased autonomy from hosts. Thus, warming could erode the ecological function and promote symbiont autonomy in photosymbiosis over evolutionary timescales.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Theodore S. Switzer, Sean F. Keenan, Ryan T. Munnelly, Sheri L. Parks, Brett R. Pittinger, Theresa K. Warner, Richard E. Matheson Jr., Ryan Maloney
ABSTRACT: Hard substrate and vertical relief are limited habitat resources for reef-associated species in many regions. On the West Florida Shelf (WFS) of the Gulf of Mexico, red grouper Epinephelus morio act as ecosystem engineers by excavating sediments to expose limestone bedrock. Excavations can exceed 25 m in diameter and 2 m in depth and are among the most abundant WFS seafloor features at depths between 40 and 110 m. As part of a survey of hard-bottom habitats and associated reef fish assemblages, 1203 excavations were identified in WFS waters along the Florida Panhandle between 2014 and 2019. These excavations often contained subsided artificial reef material within their interior and infrequently included E. morio among observed fishes. We video-identified red snapper Lutjanus campechanus excavating sediments around 2 subsided artificial reefs in 2015 and 2017 for a total of approximately 56 min of excavation activity. A total of 24 excavation events were documented around a tire pile in 2015, and 5 were documented around a pyramid-shaped reef module in 2017. These observations help to explain the subsidence of artificial reefs and apparent excavation around their bases despite the scarcity of previously known excavating species. This suggests that L. campechanus might be ecosystem engineers on the WFS.
{"title":"Red snapper excavate sediments around artificial reefs: observations of ecosystem-engineering behavior by a widely distributed lutjanid","authors":"Theodore S. Switzer, Sean F. Keenan, Ryan T. Munnelly, Sheri L. Parks, Brett R. Pittinger, Theresa K. Warner, Richard E. Matheson Jr., Ryan Maloney","doi":"10.3354/ab00768","DOIUrl":"https://doi.org/10.3354/ab00768","url":null,"abstract":"ABSTRACT: Hard substrate and vertical relief are limited habitat resources for reef-associated species in many regions. On the West Florida Shelf (WFS) of the Gulf of Mexico, red grouper <i>Epinephelus morio</i> act as ecosystem engineers by excavating sediments to expose limestone bedrock. Excavations can exceed 25 m in diameter and 2 m in depth and are among the most abundant WFS seafloor features at depths between 40 and 110 m. As part of a survey of hard-bottom habitats and associated reef fish assemblages, 1203 excavations were identified in WFS waters along the Florida Panhandle between 2014 and 2019. These excavations often contained subsided artificial reef material within their interior and infrequently included <i>E. morio</i> among observed fishes. We video-identified red snapper <i>Lutjanus campechanus</i> excavating sediments around 2 subsided artificial reefs in 2015 and 2017 for a total of approximately 56 min of excavation activity. A total of 24 excavation events were documented around a tire pile in 2015, and 5 were documented around a pyramid-shaped reef module in 2017. These observations help to explain the subsidence of artificial reefs and apparent excavation around their bases despite the scarcity of previously known excavating species. This suggests that <i>L. campechanus</i> might be ecosystem engineers on the WFS.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140887053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shiyun Chi, Jun Hu, Ming Li, Jinxiu Zheng, Hongjun Wang, Juxiang Hu
ABSTRACT: Few studies have explored the relationship between benthic and planktonic assemblages in reservoirs, despite their role in food chains and maintaining ecological functions. Macroinvertebrates play a crucial role in food webs and contribute about 42% of whole-lake secondary productivity. Therefore, their status is vital for maintaining good ecological functions. In this study, we selected Nanwan Reservoir, a eutrophic thermally stratified reservoir in China, to evaluate the community of macroinvertebrates in different seasons and explore the relationships between macroinvertebrate assemblages and different planktonic groups, including phytoplankton, protozoans, rotifers, and planktonic crustaceans. Cyanophyta and Bacillariophyta dominated the phytoplankton assemblages, and their proportions varied with seasons. The bad community of macroinvertebrates in summer, autumn, and winter could be attributed to the excessive growth of Cyanophyta or other phytoplankton. Based on the results of partial least squares regression, an algorithm used for prediction, we determined that the excessive growth of algae, crustaceans, protozoans, and Cyanophyta was detrimental to the development of macroinvertebrates, and was indicative of high nutrient loads in the reservoir. However, the growth of Bacillariophyta, Chrysophyta, and Euglenophyta was advantageous to macroinvertebrate assemblages and indicated a better ecological condition of the reservoir. The results of partial least squares structural equation modeling demonstrated close associations between phytoplankton and both zooplankton and macroinvertebrates, indicating their interdependence in this reservoir system. Our study results imply that the status of macroinvertebrates can be predicted by the abundance of some planktonic assemblages, and cost savings from selecting one of the planktonic groups to monitor ecological conditions could be accomplished in future studies.
{"title":"Benthic assemblages in relation to planktonic assemblages in a eutrophic, thermally stratified reservoir","authors":"Shiyun Chi, Jun Hu, Ming Li, Jinxiu Zheng, Hongjun Wang, Juxiang Hu","doi":"10.3354/ab00767","DOIUrl":"https://doi.org/10.3354/ab00767","url":null,"abstract":"ABSTRACT: Few studies have explored the relationship between benthic and planktonic assemblages in reservoirs, despite their role in food chains and maintaining ecological functions. Macroinvertebrates play a crucial role in food webs and contribute about 42% of whole-lake secondary productivity. Therefore, their status is vital for maintaining good ecological functions. In this study, we selected Nanwan Reservoir, a eutrophic thermally stratified reservoir in China, to evaluate the community of macroinvertebrates in different seasons and explore the relationships between macroinvertebrate assemblages and different planktonic groups, including phytoplankton, protozoans, rotifers, and planktonic crustaceans. Cyanophyta and Bacillariophyta dominated the phytoplankton assemblages, and their proportions varied with seasons. The bad community of macroinvertebrates in summer, autumn, and winter could be attributed to the excessive growth of Cyanophyta or other phytoplankton. Based on the results of partial least squares regression, an algorithm used for prediction, we determined that the excessive growth of algae, crustaceans, protozoans, and Cyanophyta was detrimental to the development of macroinvertebrates, and was indicative of high nutrient loads in the reservoir. However, the growth of Bacillariophyta, Chrysophyta, and Euglenophyta was advantageous to macroinvertebrate assemblages and indicated a better ecological condition of the reservoir. The results of partial least squares structural equation modeling demonstrated close associations between phytoplankton and both zooplankton and macroinvertebrates, indicating their interdependence in this reservoir system. Our study results imply that the status of macroinvertebrates can be predicted by the abundance of some planktonic assemblages, and cost savings from selecting one of the planktonic groups to monitor ecological conditions could be accomplished in future studies.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140572304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rashid Alijani Ardeshir, Sarina Shahidokht, Mehdi Mirzaei, Sara Rastgar
ABSTRACT: Fipronil (FPN) is an insecticide used in agriculture. This study focused on the biotransformation process and the histopathological effects of FPN in the liver of grass carp. Fish were exposed to environmental concentrations of FPN (3, 6, and 10 ug l-1) for up to 14 d. The alterations in phase I and II biotransformation enzyme activity (ethoxyresorufin-O-deethylase [EROD] and glutathione-S-transferase [GST]), malondialdehyde (MDA) content, and histopathology in the liver were studied on the 1st, 3rd, 7th, and 14th days. Results showed that EROD (dose-dependent) and GST activity (time-dependent) increased. The MDA content increased in a time- and dose-dependent manner. The most common types of hepatological damage were steatosis, vein dilatation, pyknosis, and increased melanomacrophage centers, probably due to oxidative stress originating from biotransformation enzyme activity (R2 = 0.88 for GST and MDA). The degree of tissue change (DTC) at the highest dose indicated moderate damage to the liver (R2 = 0.82 for GST and DTC). Nevertheless, the level of EROD and GST activity and MDA content indicated complex interactions among various phase I and phase II biotransformation enzymes which should be investigated in future studies with more replications.
摘要：氟虫腈（FPN）是一种用于农业的杀虫剂。本研究主要关注氟虫腈在草鱼肝脏中的生物转化过程和组织病理学效应。研究了第 1、3、7 和 14 天草鱼肝脏中 I 期和 II 期生物转化酶活性（乙氧基甲磺酰-O-脱乙基酶 [EROD] 和谷胱甘肽-S-转移酶 [GST]）、丙二醛 (MDA) 含量和组织病理学的变化。结果表明，EROD（剂量依赖性）和 GST 活性（时间依赖性）增加。MDA 含量的增加与时间和剂量有关。最常见的肝损伤类型是脂肪变性、静脉扩张、脓毒血症和黑色素细胞中心增加，这可能是由于生物转化酶活性引起的氧化应激所致（GST 和 MDA 的 R2 = 0.88）。最高剂量下的组织变化程度（DTC）表明肝脏受到了中度损伤（GST 和 DTC 的 R2 = 0.82）。不过，EROD 和 GST 活性水平以及 MDA 含量表明，各种 I 期和 II 期生物转化酶之间存在着复杂的相互作用，这一点应在今后进行更多重复的研究中加以探讨。
{"title":"The effect of fipronil exposure on the activity of biotransformation enzymes and histology in the liver of grass carp","authors":"Rashid Alijani Ardeshir, Sarina Shahidokht, Mehdi Mirzaei, Sara Rastgar","doi":"10.3354/ab00765","DOIUrl":"https://doi.org/10.3354/ab00765","url":null,"abstract":"ABSTRACT: Fipronil (FPN) is an insecticide used in agriculture. This study focused on the biotransformation process and the histopathological effects of FPN in the liver of grass carp. Fish were exposed to environmental concentrations of FPN (3, 6, and 10 ug l<sup>-1</sup>) for up to 14 d. The alterations in phase I and II biotransformation enzyme activity (ethoxyresorufin-O-deethylase [EROD] and glutathione-S-transferase [GST]), malondialdehyde (MDA) content, and histopathology in the liver were studied on the 1st, 3rd, 7th, and 14th days. Results showed that EROD (dose-dependent) and GST activity (time-dependent) increased. The MDA content increased in a time- and dose-dependent manner. The most common types of hepatological damage were steatosis, vein dilatation, pyknosis, and increased melanomacrophage centers, probably due to oxidative stress originating from biotransformation enzyme activity (R<sup>2</sup> = 0.88 for GST and MDA). The degree of tissue change (DTC) at the highest dose indicated moderate damage to the liver (R<sup>2</sup> = 0.82 for GST and DTC). Nevertheless, the level of EROD and GST activity and MDA content indicated complex interactions among various phase I and phase II biotransformation enzymes which should be investigated in future studies with more replications.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Timothy D. Mussen, Gry Mine Berg, Sara Driscoll, Justin D. Nordin, Lisa C. Thompson
ABSTRACT: Shallow-water habitats are being restored in the Sacramento-San Joaquin River Delta with the goal of enhancing phytoplankton production and food availability for higher trophic levels. However, elevated grazing pressure from the non-native freshwater clam Corbicula fluminea and localized depletions of dissolved inorganic nitrogen may limit phytoplankton biomass accumulation in restored habitats. To evaluate interactions between nutrients and grazing on phytoplankton productivity and biomass accumulation, Sacramento River water high or low in phytoplankton biomass was amended with wastewater effluent, presence of C. fluminea, or both, in 48 h in situ incubations. We measured changes in chl a concentration, phytoplankton community composition, and photosynthetic efficiency as well as carbon and nitrogen uptake rates as indicators of phytoplankton responses. Diatoms dominated phytoplankton communities before and after incubation. Chl a concentrations increased 0.7 and 7.4 times in the high and low phytoplankton biomass controls, respectively, and 4.5 and 14 times in the high and low phytoplankton biomass effluent-added treatments, respectively. In the clam treatments, chl a accumulation was suppressed to near zero regardless of effluent additions or initial phytoplankton biomass. In treatments with clams and effluent combined, phytoplankton photosynthetic efficiency was nearly 50% lower than in the effluent-only treatments, suggesting phytoplankton were stressed in the presence of clams. This experiment demonstrated that the presence of clams can prevent the accumulation of phytoplankton biomass, both directly by clam filtering and indirectly by depressing phytoplankton photosynthetic efficiency and rate of growth. We recommend that future wetland restoration projects promoting increased phytoplankton biomass assess clam settlement likelihood as well as nutrient availability.
ABSTRACT: 萨克拉门托-圣华金河三角洲正在恢复浅水生境，目的是提高浮游植物产量，为更高营养级提供食物。然而，非本地淡水蛤蜊（Corbicula fluminea）高强度的食草压力和局部地区溶解无机氮的消耗可能会限制恢复生境中浮游植物生物量的积累。为了评估营养物质和放牧对浮游植物生产力和生物量积累的相互作用，我们在萨克拉门托河浮游植物生物量较高或较低的河水中添加了废水、C. fluminea 或两者，并进行了 48 小时的原位培养。我们测量了 chl a 浓度、浮游植物群落组成、光合效率以及碳和氮吸收率的变化，以此作为浮游植物反应的指标。培养前后，硅藻在浮游植物群落中占主导地位。在高浮游植物生物量对照组和低浮游植物生物量对照组中，Chl a 浓度分别增加了 0.7 倍和 7.4 倍；在高浮游植物生物量处理组和低浮游植物生物量处理组中，Chl a 浓度分别增加了 4.5 倍和 14 倍。在蛤处理中，无论污水添加量或初始浮游植物生物量如何，chl a 的积累都被抑制到接近于零。在有蛤蜊和污水的处理中，浮游植物的光合效率比仅有污水的处理低近 50%，这表明浮游植物在有蛤蜊的情况下受到了压力。该实验表明，蛤类的存在可以防止浮游植物生物量的积累，既可以通过蛤类的直接过滤作用，也可以通过抑制浮游植物的光合效率和生长速度来间接防止浮游植物生物量的积累。我们建议，未来促进浮游植物生物量增加的湿地恢复项目应评估蛤类定居的可能性以及营养物质的可用性。
{"title":"Clams on stilts: a phytoplankton bioassay investigating effects of wastewater effluent amendments and Corbicula fluminea grazing","authors":"Timothy D. Mussen, Gry Mine Berg, Sara Driscoll, Justin D. Nordin, Lisa C. Thompson","doi":"10.3354/ab00764","DOIUrl":"https://doi.org/10.3354/ab00764","url":null,"abstract":"ABSTRACT: Shallow-water habitats are being restored in the Sacramento-San Joaquin River Delta with the goal of enhancing phytoplankton production and food availability for higher trophic levels. However, elevated grazing pressure from the non-native freshwater clam <i>Corbicula fluminea</i> and localized depletions of dissolved inorganic nitrogen may limit phytoplankton biomass accumulation in restored habitats. To evaluate interactions between nutrients and grazing on phytoplankton productivity and biomass accumulation, Sacramento River water high or low in phytoplankton biomass was amended with wastewater effluent, presence of <i>C. fluminea</i>, or both, in 48 h <i>in situ</i> incubations. We measured changes in chl <i>a</i> concentration, phytoplankton community composition, and photosynthetic efficiency as well as carbon and nitrogen uptake rates as indicators of phytoplankton responses. Diatoms dominated phytoplankton communities before and after incubation. Chl <i>a</i> concentrations increased 0.7 and 7.4 times in the high and low phytoplankton biomass controls, respectively, and 4.5 and 14 times in the high and low phytoplankton biomass effluent-added treatments, respectively. In the clam treatments, chl <i>a</i> accumulation was suppressed to near zero regardless of effluent additions or initial phytoplankton biomass. In treatments with clams and effluent combined, phytoplankton photosynthetic efficiency was nearly 50% lower than in the effluent-only treatments, suggesting phytoplankton were stressed in the presence of clams. This experiment demonstrated that the presence of clams can prevent the accumulation of phytoplankton biomass, both directly by clam filtering and indirectly by depressing phytoplankton photosynthetic efficiency and rate of growth. We recommend that future wetland restoration projects promoting increased phytoplankton biomass assess clam settlement likelihood as well as nutrient availability.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140129882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT: Plateau rivers are considered regional water resource depots, hydropower energy bases, cradles of aquatic dispersal, and barriers to invasive alien species. In this study, 20 major plateau rivers from Guizhou Province, China, were studied to (1) investigate the composition, functional feeding group distribution, and diversity of macroinvertebrates; and (2) assess the ecosystem health of the rivers using the macroinvertebrate Family Biotic Index. Among the macroinvertebrate species, the dammed river sections primarily contained Corbicula fluminea and C. nitens from the Lamellibranchia, the urban river sections harbored Bellamya aeruginosa and Semisulcospira cancellata from the Gastropoda, and the reference river sections contained sensitive taxa including mayfly Ecdyonurus yoshidae and caddisfly Stenopsyche tlenmushanensis. Among the major plateau rivers in Guizhou, urban river sections exhibited the highest density of macrobenthic organisms. The Shannon-Wiener index was lowest in dammed sections, followed by urban sections, while reference sections exhibited the highest diversity. As for functional feeding groups, the density of filter feeders was significantly higher than that of other groups. In contrast, the density of gatherer-collectors and the shredders was relatively low. Assessment of the aquatic ecosystem health in Guizhou Plateau rivers showed that dammed sections were primarily in an unhealthy state, urban sections mainly fell into the sub-healthy category, and reference sections had a relatively good health status. The results from this study provide baseline data that is useful for water resources management, hydropower energy utilization, and ecological and environmental protection of the plateau rivers.
{"title":"Macroinvertebrate community composition and river health assessment in plateau rivers of Guizhou Province, China","authors":"Sujuan Ge, Ziwu Fan, Yifan Su","doi":"10.3354/ab00763","DOIUrl":"https://doi.org/10.3354/ab00763","url":null,"abstract":"ABSTRACT: Plateau rivers are considered regional water resource depots, hydropower energy bases, cradles of aquatic dispersal, and barriers to invasive alien species. In this study, 20 major plateau rivers from Guizhou Province, China, were studied to (1) investigate the composition, functional feeding group distribution, and diversity of macroinvertebrates; and (2) assess the ecosystem health of the rivers using the macroinvertebrate Family Biotic Index. Among the macroinvertebrate species, the dammed river sections primarily contained <i>Corbicula fluminea</i> and <i>C. nitens</i> from the Lamellibranchia, the urban river sections harbored <i>Bellamya aeruginosa</i> and <i>Semisulcospira cancellata</i> from the Gastropoda, and the reference river sections contained sensitive taxa including mayfly <i>Ecdyonurus yoshidae</i> and caddisfly <i>Stenopsyche tlenmushanensis</i>. Among the major plateau rivers in Guizhou, urban river sections exhibited the highest density of macrobenthic organisms. The Shannon-Wiener index was lowest in dammed sections, followed by urban sections, while reference sections exhibited the highest diversity. As for functional feeding groups, the density of filter feeders was significantly higher than that of other groups. In contrast, the density of gatherer-collectors and the shredders was relatively low. Assessment of the aquatic ecosystem health in Guizhou Plateau rivers showed that dammed sections were primarily in an unhealthy state, urban sections mainly fell into the sub-healthy category, and reference sections had a relatively good health status. The results from this study provide baseline data that is useful for water resources management, hydropower energy utilization, and ecological and environmental protection of the plateau rivers.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139656720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Khanbo, S. U-thoomporn, W. Kongkachana, S. Charoensri, N. Narong, C. Maknual, P. Chumriang, P. Maprasop, P. Wanthongchai, S. Tangphatsornruang, W. Pootakham
{"title":"Genetic diversity and population structure of the Upriver Orange Mangrove (Bruguiera sexangula) along the coastlines of Thailand","authors":"S. Khanbo, S. U-thoomporn, W. Kongkachana, S. Charoensri, N. Narong, C. Maknual, P. Chumriang, P. Maprasop, P. Wanthongchai, S. Tangphatsornruang, W. Pootakham","doi":"10.3354/ab00761","DOIUrl":"https://doi.org/10.3354/ab00761","url":null,"abstract":"","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73660504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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