The current study investigates the toxic effects of acute dose of an endocrine disruptor atrazine on Grass carp (<em>Ctenepharyngodon idella</em>) using histopathological changes as biomarkers. Histopathol...The current study investigates the toxic effects of acute dose of an endocrine disruptor atrazine on Grass carp (<em>Ctenepharyngodon idella</em>) using histopathological changes as biomarkers. Histopathology is promising field for research in aquatic toxicology, in this manner vital organs;brain, gills, and liver tissues were inspected histological after exposing to sublethal groupings of atrazine 0.025 and 0.03 μl/L for 3, 6, 9, 12 and 15 days individually with equal untreated control group. Against various doses, rapid movements, gulping of air and jumping of fish to scat from toxic medium were noticed. Various severe (+++) morphological modifications in tissue were documented in comparison with control group comprised of degenerated neurons, vacuolization, inflammatory cells infiltration and neural necrosis in brain tissue. The most well-known gills tissue alteration at all concentrations of atrazine was epithelial hyperplasia, desquamation, epithelial lifting and smaller aneurism while hepatic injuries were described by overcast expanding of hepatocytes esteemed as cloudy swelling of hepatocytes followed by karyolysis, karyohexis and dilation of sinusoids which shows that atrazine introduction upgraded the toxicosis impacts with the increase concentration, influenced the strength of the fish, inferable from histological inconsistencies.展开更多
The effects of digested sludge on the ultrastructure of gills of Sarotherodon mossambicus were investigated.Samples of digested sludge were collected from the Shatin Sewage Treatment Plant in Hong Kong and.they were (...The effects of digested sludge on the ultrastructure of gills of Sarotherodon mossambicus were investigated.Samples of digested sludge were collected from the Shatin Sewage Treatment Plant in Hong Kong and.they were (1)sun-dried(NS)or(2)sterilized in an autoclave(SS).They were then used as supplementary fish feed to cultivate the freshwater tilapia,S.mossambicus,for 50 days under laboratory conditions.The SS at low dosage(25%)had the lowest toxicity among different treatments.A swelling of lamellar epithelium,the enlargement of the subepitlaelial space,the collapse of capillaries,and the infiltration of polymorphonuclear cells in the lamellae offish gills were common to fish fed 50 to 100% NS and SS.The thickening of the basal lamina in the gill lamellae is a common feature found in the sludge-treated fish.1989 Academic Press.Inc.展开更多
The distribution and concentrations of Cd, Cu, Pb and Zn were determined in the gills and remaining soft tissues of Perna viridis collected from 12 geographical sites (10 from the west and 2 from the east coastal wate...The distribution and concentrations of Cd, Cu, Pb and Zn were determined in the gills and remaining soft tissues of Perna viridis collected from 12 geographical sites (10 from the west and 2 from the east coastal waters) of Peninsular Malaysia. All samples showed that the levels of Cd, Pb and Zn were generally higher in the gill than those in the remaining soft tissues. These results could be due to the fact that gills are the first organ of metal accumulation and larger surface area with mucus sheets in the organ. Since the mussel gill is a better accumulator of Cd, Pb and Zn of ambient seawater than remaining soft tissue, it is a potential indicator of ambient levels of dissolved metals in the ambient seawater. However, further validations based on laboratory conditions are needed.展开更多
This paper deals with the proportional distribution, niche breadth and niche overlap of two metazoan parasites(copepods species, Ergasilus anchoratus Markewitsch, 1946 and Pseudergasilus parasiluri Yamaguti, 1936) and...This paper deals with the proportional distribution, niche breadth and niche overlap of two metazoan parasites(copepods species, Ergasilus anchoratus Markewitsch, 1946 and Pseudergasilus parasiluri Yamaguti, 1936) and monogeneans (in the genus Silurodiscoides Gussev, 1976) found on gills of the fish, Silurus asotus L. from Jiangkou Reservoir in Jiangxi Province,China. E.anchoratus was the common and dominant metazoan parasite on gills of the fish in this locality as indicated by the higher infection levels, and distributed almost evenly on gill arches without any observed gill arch preference, as shown by the wide proportional distribution and broad niche breadth. P. parasiluri and monogeneans in Silurodiscoides were found also without any significant gill arch preference although they had a rather narrow niche breadth. The observed significant overlap between P. parasiluri and Silurodiscoides spp. may be simply due to the lower infection levels of the parasites. The observed pattern of unrestricted distributions of the parasitic copepods on gills of the fish may be accounted for, at least in part, by the moving ability of the copepods, and may also indicate that the parasite does not exhibit any feature of gill arch preference. However, further experimental research is needed to verify the microhabitat distribution of the parasites.展开更多
There has been an increasing interest in marine oysters (order: Petridae) in recent years because their numbers are declining in many parts of the world and also because they are used as monitors of pollution. The pre...There has been an increasing interest in marine oysters (order: Petridae) in recent years because their numbers are declining in many parts of the world and also because they are used as monitors of pollution. The present study describes the microscopic structure of gills as viewed by light and electron microscopy in two locations selected in Alexandria coast, Eastern Harbor (E.H.) and El Asafra. The specimens in the E.H. represent the presence of extracellular mineralized granules.展开更多
Moringa oleifera is well known as a highly nutritious plant and a water purifier in fish culture.Tilapia fish has many impressive qualities making them very suitable for aquaculture.Therefore,this study aimed to evalu...Moringa oleifera is well known as a highly nutritious plant and a water purifier in fish culture.Tilapia fish has many impressive qualities making them very suitable for aquaculture.Therefore,this study aimed to evaluate the effect of supplementation of Moringa oleifera aqueous extract(MOAE)at varying concentrations(0,100,200,and 400 mg/kg diet for 90 days)on growth performance,hematological,and some biochemical parameters of Nile tilapia.Additionally,histological changes and immunohistochemical expression of caspase 3 in gills and livers were evaluated.Significant enhancements(P<0.05)in the final weight,weight gain,specific growth rate,red blood cells,hemoglobin,packed cell volume,white blood cells,and total serum protein were observed in fish fed 200 mg MOAE/kg diet compared with other groups.However,a significant reduction(P<0.05)of liver and kidney function tests and non-significant changes in lipid profile were recorded.On the other hand,fish fed 400 mg MOAE/kg diet revealed disturbance in the corresponding parameters.Severe histological degenerative changes were detected in the gills and liver of fish fed 400 mg MOAE/kg diet.In comparison,fish fed 200 mg MOAE/kg diet showed the best histo-architectures of these organs compared with other groups.Concomitant immune expressions of caspase 3 were determined where gills and liver of fish fed 400 mg MOAE/kg diet revealed extensive number of positive caspase 3 cells indicating severe apoptotic features.Accordingly,a dietary MOAE at 200 mg/kg diet is recommended to improve the growth performance,hematological parameters,liver and kidney functions in Nile tilapia.Meanwhile,caution must be considered when using MOAE at a concentration over 200 mg/kg diet.展开更多
Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas det...Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas detection.In this paper,to improve efficiency in the detection of the dissolved gas phase in seawater,a better flat membrane contactor is proposed to achieve efficient degassing,inspired by the way fish breathe underwater and the special structure of fish gills.The bioinspired flow channel structures in the flat membrane contactor are suggested along with the distribution of internal blood vessels in the gill platelet and the feature of the gill platelet surface.Using 3D printing,the special degassing devices are manufactured,and comparative analysis of relevant flow parameters is made using different flow channels,combined with the CFD simulation.The final result showed that the proposed flow channel in the degasser achieves a better degassing effect compared with conventional flow channel when the membrane contact area is limited,which can provide good conditions for subsequent gas detection.展开更多
We focused on elucidating the toxic effects of water-borne copper on the giant freshwater prawn Macrobrachium rosenbergii.After seven days of exposure to copper(Cu2+)at concentrations ranging from 0.01 mg L–1 to 0.5 ...We focused on elucidating the toxic effects of water-borne copper on the giant freshwater prawn Macrobrachium rosenbergii.After seven days of exposure to copper(Cu2+)at concentrations ranging from 0.01 mg L–1 to 0.5 mg L–1,three isozymes,malate dehydrogenase,alkaline phosphatase and esterase,were analyzed and compared using polyacrylamide electrophoresis(PAGE)and biochemical staining.The results indicated that the electrophoretic patterns of the isozymes showed a copper-concentration-related difference.Low doses of copper stimulated strong expression of the three isozymes.Electrophoretic patterns of malate dehydrogenase and alkaline phosphatase gradually became weaker or even lost as the level of copper increased.In contrast,esterase patterns exhibited an increased molecular heterogeneity at higher copper concentrations.A transmission electron microscope was used to study ultrastructure differences in the gills and hepatopancreas of M.rosenbergii,and the results showed significant structural damage at increased levels of copper compared with the control group.The basement mem-branes and mitochondira in the gills were seriously damaged,the cuticle electron density distribution was not homogeneous,and an infolded basement membrane,circularized nucleus,disintegrated nuclear membrane,and decreased mitochondria number and size were observed in the gills.Similarly,flowing out of karyoplasms,partly falling microvilli,decreased mitochondrion,partly disappeared mitochondrial cristae,and a thinned matrix were observed in the hepatopancreas.These findings indicate that exposure to elevated copper levels might damage the ultrastructure of the gills and hepatopancreas of M.rosenbergii and might further weaken their normal physical activities.Isozymes were quite sensitive to environmental stress and changes in isozyme elctrophoretic patterns might be effective biomarkers of environmental contamination.展开更多
The Brantas River is currently vulnerable to microplastics pollution.Microplastics not only pollute the aquatic environment but also enter the body of fish and other aquatic organisms.This research is aimed at decidin...The Brantas River is currently vulnerable to microplastics pollution.Microplastics not only pollute the aquatic environment but also enter the body of fish and other aquatic organisms.This research is aimed at deciding if microplastics were present in the waters and the gills and digestive tract of the Gambusia affinis fish of the river.It also looked at differences in the abundance of several types of microplastics found in the various organ samples and locations.Field research was conducted from January 2020 to March 2020.The microplastics were identified by type,size,color,and the abundance of each type was calculated.The types of microplastics identified were fragments,fibres,films,and pellets.Microplastics of 0.1 mm size are predominant and formed about 76%-100%of the microplastics that were found.Black microplastics were more common in water samples(24%),gills(43%),and digestive tract(46%).The greatest abundance of microplastic fragments was found in water samples of 4066.67 particles/m^(3),1352.78 particles/gram in gill samples,and 2138.89 particles/gram in the digestive tract.Multivariate tests for variants of microplastic types found in the organs at different sampling locations gave a p-value<0.05.These results indicate a difference in the abundance values of microplastic species in different organ samples and sites.展开更多
Objective:To study the histopathological symptoms owing to cymothoid isopod that were categorised as gross lesions.Methods:Nature of damage fish tissues and gills were taken from the parasite attachment area of infest...Objective:To study the histopathological symptoms owing to cymothoid isopod that were categorised as gross lesions.Methods:Nature of damage fish tissues and gills were taken from the parasite attachment area of infested and uninfested fishes which were cut out in fresh condition fixed in 10%buffered neutral formalin.Fresh and recently preserved tissues and gills were washed in tap water and dehydrated using alcohol series.The tissues gills were then cleaned in methylbenzoate and benzene and embedded in paraffin wax.The serial sections cutting 4 to 5 m thickness,were stained with Erlich’s haematoxylin and Eosin for histopathological analysis.Results:In normal muscle tissue,the tensile strength of muscle fibers with extra cellular matrix collagen was extensively tight associated.This gave a rigid musculature pattern to the tissues.Infested fish exhibited histopathological anomalies such as tissue reactions,primarily associated with the formation of granulomas consisted of macrophages and epitheleioid cells,which were occasionally surrounded by a thin rim of fibroblasts.The infestations such as lipofibrosis,hyperaemia,haemorhagic lesions and penetration of dactylus usually pressure atrophy often accompanied by the presence of parasites.Lesions had well developed granulomas that underlined in the muscle or overlying subcutaneous tissue,form these spread to underlying organs.Conclusions:It could be concluded that the infection studies of parasite that attaches or settles on the host body,at first,causes localized inflammatory changes,but with time,assuring a different or diffused character.The changes always begin with hyperaemia in the angles between adjacent sides at the site of attachment and then move towards deeply situated area.展开更多
Gill morphological changes and physiological responses in juvenile large yellow croaker(Larimichthys crocea)were examined upon exposure to low salinity after indoor culture of the fish at salinities of 2,4,6,8,and 24...Gill morphological changes and physiological responses in juvenile large yellow croaker(Larimichthys crocea)were examined upon exposure to low salinity after indoor culture of the fish at salinities of 2,4,6,8,and 24‰(control group).The thickness of the lamellae was significantly higher in the low-salinity groups than in the control group;in contrast,the interlamellar space was significantly lower in the low-salinity groups than in the control group.Additionally,a significant negative correlation was found between the thickness of lamellae and interlamellar spaces(P<0.01).Mitochondria-rich cells(MRCs)were mainly found in the filament at 24‰salinity and proliferated in the lamellae at lower salinities,suggesting that filament and lamellar MRCs are responsible for ion secretion and absorption,respectively.Meanwhile,the activity of Na+/K+-ATPase(NKA)was significantly elevated with the decrease in salinity from 24‰to 4‰(P<0.05),which was consistent with MRCs proliferation.Finally,the activity of NKA declined at 2‰salinity(P<0.05),indicating the limit of osmoregulation,which was consistent with the degeneration and necrosis of the lamellae.Additionally,different levels of gill histopathological lesions,including pavement cell(PVC)exfoliation,lamellar epithelial lifting,edema,fusion,aneurism,and necrosis,were observed from salinities of 24 to 4‰,likely reducing the respiratory efficiency and compromising the health of juvenile fish.In conclusion,large yellow croaker juveniles could improve the osmoregulatory capacity by increasing lamellar MRCs and NKA activity with the decrease in salinity from 24 to 4‰.However,the associated histopathological lesions are likely to negatively influence the fish by affecting respiration and osmoregulation,especially when the salinity is below 4‰.展开更多
Objective:To monitor the response of gills of Cyprinus carpio var. communis to LC_(50) levels of ammonia over a period of 96 h by bath exposure, using scanning electron microscopy (SEM). Methods: Cyprinus carpio procu...Objective:To monitor the response of gills of Cyprinus carpio var. communis to LC_(50) levels of ammonia over a period of 96 h by bath exposure, using scanning electron microscopy (SEM). Methods: Cyprinus carpio procured from a local fish farm in Vadalore, Cuddalore District, Tamil Nadu, India were acclimatized under laboratory conditions for 20 d. Fish were placed into experimental tanks with 20 L of water and 22 mg/L ammonia. A total of 10 fish were collected from each experimental tank every 24 h for histopathological studies. Results:Histopathological studies showed these changes in the gills:secondary lamellar fusion, haemorrhage, oedema, epithelial hyperplasia, and chloride cell proliferation. Occasionally, multifocal necrosis of inter-lamellar regions of gill filaments but with no apparent haemorrhage was observed under electron microscopy. Conclusion:The present study shows that histopathological and ultrastructural alterations in gills are useful indicators for ammonia toxicity in Cyprinus carpio.展开更多
Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus i...Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus in response to short-term low salinity stress,the experiments of gradually decline and recovery as well as abrupt decline in salinity were carried out.The results showed that P.trituberculatus could survive in a certain low salinity range in the short term,and salinity 12 was the lowest tolerable salinity under the present experimental conditions.The change of the hemolymph osmotic pressure displayed significant positive correlations with water salinity,and the pressure was always higher than seawater osmotic pressure.Short-term low salinity stress changed the structure and morphology of gill tissue.The expansion of gill filament ends and epithelial cell shedding were conducive to osmotic adjustment.The activities of key ion transport enzymes such as Na^(+)-K^(+)-ATPase,carbonic anhydrase and V-ATPase also changed with the osmotic regulation,while Na^(+)-K^(+)-ATPase played a dominant role.In summary,as an osmotic adjustment species,P.trituberculatus rapidly adapt to the short-term low-salinity environment by osmotic adjustment in vivo,but salinity below salinity 12 is not conducive to its survival.Our result enriched the theoretical mechanism of osmotic regulation of P.trituberculatus,providing reference for the development of aquaculture technology of P.trituberculatus.展开更多
[Objective] The curative effect of onion on bacterial rotted gill disease in grass carp was researched [Method] The combination method of taking medicine through oral and spraying was used to cure sick grass carp for ...[Objective] The curative effect of onion on bacterial rotted gill disease in grass carp was researched [Method] The combination method of taking medicine through oral and spraying was used to cure sick grass carp for 1 period of treatment in room under artificial conditions. [Result] Different concentrations of onion generated different cure rates. When the combination was adding 1.0% - 2.0% medicine into feed and spraying 2.0 g,/m3 - 5.0 g,/m3, the curative result was the best with cure rate was 70% -90% [ Conclusion] The onion was effective on curing bacterial rotted gill disease in grass carp and could be taken as curative medicine.展开更多
文摘The current study investigates the toxic effects of acute dose of an endocrine disruptor atrazine on Grass carp (<em>Ctenepharyngodon idella</em>) using histopathological changes as biomarkers. Histopathology is promising field for research in aquatic toxicology, in this manner vital organs;brain, gills, and liver tissues were inspected histological after exposing to sublethal groupings of atrazine 0.025 and 0.03 μl/L for 3, 6, 9, 12 and 15 days individually with equal untreated control group. Against various doses, rapid movements, gulping of air and jumping of fish to scat from toxic medium were noticed. Various severe (+++) morphological modifications in tissue were documented in comparison with control group comprised of degenerated neurons, vacuolization, inflammatory cells infiltration and neural necrosis in brain tissue. The most well-known gills tissue alteration at all concentrations of atrazine was epithelial hyperplasia, desquamation, epithelial lifting and smaller aneurism while hepatic injuries were described by overcast expanding of hepatocytes esteemed as cloudy swelling of hepatocytes followed by karyolysis, karyohexis and dilation of sinusoids which shows that atrazine introduction upgraded the toxicosis impacts with the increase concentration, influenced the strength of the fish, inferable from histological inconsistencies.
文摘The effects of digested sludge on the ultrastructure of gills of Sarotherodon mossambicus were investigated.Samples of digested sludge were collected from the Shatin Sewage Treatment Plant in Hong Kong and.they were (1)sun-dried(NS)or(2)sterilized in an autoclave(SS).They were then used as supplementary fish feed to cultivate the freshwater tilapia,S.mossambicus,for 50 days under laboratory conditions.The SS at low dosage(25%)had the lowest toxicity among different treatments.A swelling of lamellar epithelium,the enlargement of the subepitlaelial space,the collapse of capillaries,and the infiltration of polymorphonuclear cells in the lamellae offish gills were common to fish fed 50 to 100% NS and SS.The thickening of the basal lamina in the gill lamellae is a common feature found in the sludge-treated fish.1989 Academic Press.Inc.
文摘The distribution and concentrations of Cd, Cu, Pb and Zn were determined in the gills and remaining soft tissues of Perna viridis collected from 12 geographical sites (10 from the west and 2 from the east coastal waters) of Peninsular Malaysia. All samples showed that the levels of Cd, Pb and Zn were generally higher in the gill than those in the remaining soft tissues. These results could be due to the fact that gills are the first organ of metal accumulation and larger surface area with mucus sheets in the organ. Since the mussel gill is a better accumulator of Cd, Pb and Zn of ambient seawater than remaining soft tissue, it is a potential indicator of ambient levels of dissolved metals in the ambient seawater. However, further validations based on laboratory conditions are needed.
文摘This paper deals with the proportional distribution, niche breadth and niche overlap of two metazoan parasites(copepods species, Ergasilus anchoratus Markewitsch, 1946 and Pseudergasilus parasiluri Yamaguti, 1936) and monogeneans (in the genus Silurodiscoides Gussev, 1976) found on gills of the fish, Silurus asotus L. from Jiangkou Reservoir in Jiangxi Province,China. E.anchoratus was the common and dominant metazoan parasite on gills of the fish in this locality as indicated by the higher infection levels, and distributed almost evenly on gill arches without any observed gill arch preference, as shown by the wide proportional distribution and broad niche breadth. P. parasiluri and monogeneans in Silurodiscoides were found also without any significant gill arch preference although they had a rather narrow niche breadth. The observed significant overlap between P. parasiluri and Silurodiscoides spp. may be simply due to the lower infection levels of the parasites. The observed pattern of unrestricted distributions of the parasitic copepods on gills of the fish may be accounted for, at least in part, by the moving ability of the copepods, and may also indicate that the parasite does not exhibit any feature of gill arch preference. However, further experimental research is needed to verify the microhabitat distribution of the parasites.
文摘There has been an increasing interest in marine oysters (order: Petridae) in recent years because their numbers are declining in many parts of the world and also because they are used as monitors of pollution. The present study describes the microscopic structure of gills as viewed by light and electron microscopy in two locations selected in Alexandria coast, Eastern Harbor (E.H.) and El Asafra. The specimens in the E.H. represent the presence of extracellular mineralized granules.
文摘Moringa oleifera is well known as a highly nutritious plant and a water purifier in fish culture.Tilapia fish has many impressive qualities making them very suitable for aquaculture.Therefore,this study aimed to evaluate the effect of supplementation of Moringa oleifera aqueous extract(MOAE)at varying concentrations(0,100,200,and 400 mg/kg diet for 90 days)on growth performance,hematological,and some biochemical parameters of Nile tilapia.Additionally,histological changes and immunohistochemical expression of caspase 3 in gills and livers were evaluated.Significant enhancements(P<0.05)in the final weight,weight gain,specific growth rate,red blood cells,hemoglobin,packed cell volume,white blood cells,and total serum protein were observed in fish fed 200 mg MOAE/kg diet compared with other groups.However,a significant reduction(P<0.05)of liver and kidney function tests and non-significant changes in lipid profile were recorded.On the other hand,fish fed 400 mg MOAE/kg diet revealed disturbance in the corresponding parameters.Severe histological degenerative changes were detected in the gills and liver of fish fed 400 mg MOAE/kg diet.In comparison,fish fed 200 mg MOAE/kg diet showed the best histo-architectures of these organs compared with other groups.Concomitant immune expressions of caspase 3 were determined where gills and liver of fish fed 400 mg MOAE/kg diet revealed extensive number of positive caspase 3 cells indicating severe apoptotic features.Accordingly,a dietary MOAE at 200 mg/kg diet is recommended to improve the growth performance,hematological parameters,liver and kidney functions in Nile tilapia.Meanwhile,caution must be considered when using MOAE at a concentration over 200 mg/kg diet.
基金funded by Science-Technology Development Plan Project of Jilin Province,20210203099SF,Zhiyong ChangScience and Technology Development Project of Jilin Province,20190303061SF,Yongming Yao13th Five-Year Plan Scientific Research Foundation of the Education Department of Jilin Province,JJKH20190190KJ,Zhiyong Chang.
文摘Over the past decades,membrane-based separation processes have found numerous applications in various industries.Membrane contactor is an important part of the separation of dissolved gas in the early stage of gas detection.In this paper,to improve efficiency in the detection of the dissolved gas phase in seawater,a better flat membrane contactor is proposed to achieve efficient degassing,inspired by the way fish breathe underwater and the special structure of fish gills.The bioinspired flow channel structures in the flat membrane contactor are suggested along with the distribution of internal blood vessels in the gill platelet and the feature of the gill platelet surface.Using 3D printing,the special degassing devices are manufactured,and comparative analysis of relevant flow parameters is made using different flow channels,combined with the CFD simulation.The final result showed that the proposed flow channel in the degasser achieves a better degassing effect compared with conventional flow channel when the membrane contact area is limited,which can provide good conditions for subsequent gas detection.
基金supported by the Ministry of Personnel(Scientific Research Foundation for Returned Overseas Chinese Scholars,2004,Project No.2-105053)the Chinese Academy of Fishery Sciences for Chief Scientists(Project No.1-105011)+1 种基金the Science and Technology Department of Shanghai(Project No.07DZ12038)the Cultivation Fund of The Key Scientific and Technical Innovation Innovation Project,the Ministry of Education of China under contract(Project No.704023).
文摘We focused on elucidating the toxic effects of water-borne copper on the giant freshwater prawn Macrobrachium rosenbergii.After seven days of exposure to copper(Cu2+)at concentrations ranging from 0.01 mg L–1 to 0.5 mg L–1,three isozymes,malate dehydrogenase,alkaline phosphatase and esterase,were analyzed and compared using polyacrylamide electrophoresis(PAGE)and biochemical staining.The results indicated that the electrophoretic patterns of the isozymes showed a copper-concentration-related difference.Low doses of copper stimulated strong expression of the three isozymes.Electrophoretic patterns of malate dehydrogenase and alkaline phosphatase gradually became weaker or even lost as the level of copper increased.In contrast,esterase patterns exhibited an increased molecular heterogeneity at higher copper concentrations.A transmission electron microscope was used to study ultrastructure differences in the gills and hepatopancreas of M.rosenbergii,and the results showed significant structural damage at increased levels of copper compared with the control group.The basement mem-branes and mitochondira in the gills were seriously damaged,the cuticle electron density distribution was not homogeneous,and an infolded basement membrane,circularized nucleus,disintegrated nuclear membrane,and decreased mitochondria number and size were observed in the gills.Similarly,flowing out of karyoplasms,partly falling microvilli,decreased mitochondrion,partly disappeared mitochondrial cristae,and a thinned matrix were observed in the hepatopancreas.These findings indicate that exposure to elevated copper levels might damage the ultrastructure of the gills and hepatopancreas of M.rosenbergii and might further weaken their normal physical activities.Isozymes were quite sensitive to environmental stress and changes in isozyme elctrophoretic patterns might be effective biomarkers of environmental contamination.
文摘The Brantas River is currently vulnerable to microplastics pollution.Microplastics not only pollute the aquatic environment but also enter the body of fish and other aquatic organisms.This research is aimed at deciding if microplastics were present in the waters and the gills and digestive tract of the Gambusia affinis fish of the river.It also looked at differences in the abundance of several types of microplastics found in the various organ samples and locations.Field research was conducted from January 2020 to March 2020.The microplastics were identified by type,size,color,and the abundance of each type was calculated.The types of microplastics identified were fragments,fibres,films,and pellets.Microplastics of 0.1 mm size are predominant and formed about 76%-100%of the microplastics that were found.Black microplastics were more common in water samples(24%),gills(43%),and digestive tract(46%).The greatest abundance of microplastic fragments was found in water samples of 4066.67 particles/m^(3),1352.78 particles/gram in gill samples,and 2138.89 particles/gram in the digestive tract.Multivariate tests for variants of microplastic types found in the organs at different sampling locations gave a p-value<0.05.These results indicate a difference in the abundance values of microplastic species in different organ samples and sites.
基金Supported by Department of Science and Technology(Grant No.SR/FF/LS-088/2007)Ministry of Environment&Forest,Government of India(Grant No.22-18/2008-CS-I).
文摘Objective:To study the histopathological symptoms owing to cymothoid isopod that were categorised as gross lesions.Methods:Nature of damage fish tissues and gills were taken from the parasite attachment area of infested and uninfested fishes which were cut out in fresh condition fixed in 10%buffered neutral formalin.Fresh and recently preserved tissues and gills were washed in tap water and dehydrated using alcohol series.The tissues gills were then cleaned in methylbenzoate and benzene and embedded in paraffin wax.The serial sections cutting 4 to 5 m thickness,were stained with Erlich’s haematoxylin and Eosin for histopathological analysis.Results:In normal muscle tissue,the tensile strength of muscle fibers with extra cellular matrix collagen was extensively tight associated.This gave a rigid musculature pattern to the tissues.Infested fish exhibited histopathological anomalies such as tissue reactions,primarily associated with the formation of granulomas consisted of macrophages and epitheleioid cells,which were occasionally surrounded by a thin rim of fibroblasts.The infestations such as lipofibrosis,hyperaemia,haemorhagic lesions and penetration of dactylus usually pressure atrophy often accompanied by the presence of parasites.Lesions had well developed granulomas that underlined in the muscle or overlying subcutaneous tissue,form these spread to underlying organs.Conclusions:It could be concluded that the infection studies of parasite that attaches or settles on the host body,at first,causes localized inflammatory changes,but with time,assuring a different or diffused character.The changes always begin with hyperaemia in the angles between adjacent sides at the site of attachment and then move towards deeply situated area.
基金This work was supported by the National Key R&D Program of China(2018YFD0900906)the AoShan Talents Cultivation Program Supported by the Qingdao National Laboratory for Marine Science and Technology(2017ASTCP-ES07)+3 种基金the Key Laboratory of Sustainable Development of Marine Fisheries,Ministry of Agriculture,P.R.China(2018HY-XKQ01)the STS project of Fujian Province(2017T3016)the Ningde Normal University Special Fund Program(2019ZX406)the Fujian Province Think Tank of Science and Technology(decision-making consulting)key projects(FJKX-A1618).
文摘Gill morphological changes and physiological responses in juvenile large yellow croaker(Larimichthys crocea)were examined upon exposure to low salinity after indoor culture of the fish at salinities of 2,4,6,8,and 24‰(control group).The thickness of the lamellae was significantly higher in the low-salinity groups than in the control group;in contrast,the interlamellar space was significantly lower in the low-salinity groups than in the control group.Additionally,a significant negative correlation was found between the thickness of lamellae and interlamellar spaces(P<0.01).Mitochondria-rich cells(MRCs)were mainly found in the filament at 24‰salinity and proliferated in the lamellae at lower salinities,suggesting that filament and lamellar MRCs are responsible for ion secretion and absorption,respectively.Meanwhile,the activity of Na+/K+-ATPase(NKA)was significantly elevated with the decrease in salinity from 24‰to 4‰(P<0.05),which was consistent with MRCs proliferation.Finally,the activity of NKA declined at 2‰salinity(P<0.05),indicating the limit of osmoregulation,which was consistent with the degeneration and necrosis of the lamellae.Additionally,different levels of gill histopathological lesions,including pavement cell(PVC)exfoliation,lamellar epithelial lifting,edema,fusion,aneurism,and necrosis,were observed from salinities of 24 to 4‰,likely reducing the respiratory efficiency and compromising the health of juvenile fish.In conclusion,large yellow croaker juveniles could improve the osmoregulatory capacity by increasing lamellar MRCs and NKA activity with the decrease in salinity from 24 to 4‰.However,the associated histopathological lesions are likely to negatively influence the fish by affecting respiration and osmoregulation,especially when the salinity is below 4‰.
基金Supported by the Annamalai University Grants Commission[39-562/2010(SR)].
文摘Objective:To monitor the response of gills of Cyprinus carpio var. communis to LC_(50) levels of ammonia over a period of 96 h by bath exposure, using scanning electron microscopy (SEM). Methods: Cyprinus carpio procured from a local fish farm in Vadalore, Cuddalore District, Tamil Nadu, India were acclimatized under laboratory conditions for 20 d. Fish were placed into experimental tanks with 20 L of water and 22 mg/L ammonia. A total of 10 fish were collected from each experimental tank every 24 h for histopathological studies. Results:Histopathological studies showed these changes in the gills:secondary lamellar fusion, haemorrhage, oedema, epithelial hyperplasia, and chloride cell proliferation. Occasionally, multifocal necrosis of inter-lamellar regions of gill filaments but with no apparent haemorrhage was observed under electron microscopy. Conclusion:The present study shows that histopathological and ultrastructural alterations in gills are useful indicators for ammonia toxicity in Cyprinus carpio.
基金supported by the National Key R&D Pro-gram of China(No.2020YFD0900203)the China Agricul-ture Research System of MOF and MARAthe K.C.Wong Magna Fund in Ningbo University。
文摘Salinity is a significant environmental factor that can affect the survival,metamorphosis,growth and feeding of Portunus trituberculatus.In order to analyze the key physiological characteristics of P.trituberculatus in response to short-term low salinity stress,the experiments of gradually decline and recovery as well as abrupt decline in salinity were carried out.The results showed that P.trituberculatus could survive in a certain low salinity range in the short term,and salinity 12 was the lowest tolerable salinity under the present experimental conditions.The change of the hemolymph osmotic pressure displayed significant positive correlations with water salinity,and the pressure was always higher than seawater osmotic pressure.Short-term low salinity stress changed the structure and morphology of gill tissue.The expansion of gill filament ends and epithelial cell shedding were conducive to osmotic adjustment.The activities of key ion transport enzymes such as Na^(+)-K^(+)-ATPase,carbonic anhydrase and V-ATPase also changed with the osmotic regulation,while Na^(+)-K^(+)-ATPase played a dominant role.In summary,as an osmotic adjustment species,P.trituberculatus rapidly adapt to the short-term low-salinity environment by osmotic adjustment in vivo,but salinity below salinity 12 is not conducive to its survival.Our result enriched the theoretical mechanism of osmotic regulation of P.trituberculatus,providing reference for the development of aquaculture technology of P.trituberculatus.
基金The Natural Science Project of Xichang College(xA0509)~~
文摘[Objective] The curative effect of onion on bacterial rotted gill disease in grass carp was researched [Method] The combination method of taking medicine through oral and spraying was used to cure sick grass carp for 1 period of treatment in room under artificial conditions. [Result] Different concentrations of onion generated different cure rates. When the combination was adding 1.0% - 2.0% medicine into feed and spraying 2.0 g,/m3 - 5.0 g,/m3, the curative result was the best with cure rate was 70% -90% [ Conclusion] The onion was effective on curing bacterial rotted gill disease in grass carp and could be taken as curative medicine.
