[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
Fish gill is a multifunctional organ with role in acid-base balance, elimination of nitrogen waste and mainly gas exchange and ion regulation. There is a high energetic coast for ionregulation in freshwater fish maint...Fish gill is a multifunctional organ with role in acid-base balance, elimination of nitrogen waste and mainly gas exchange and ion regulation. There is a high energetic coast for ionregulation in freshwater fish maintained in salt water but a raise in growing taxes was observed for some species. The freshwater Nile tilapia, Oreochromis niloticus, is widely used in aquaculture farmers and the aim of this study was to investigate the changes on the gill filaments nltrastructure in fish kept under different salinities. Alevins were obtained and transported to laboratory of studies in animal stress Federal University of Paran~. Established groups in 0%0, 16%0 and 32%0 salt water with 12 animals in each one. After 30 days of exposition, the animals were anesthetized and the second gill arches were dissected and processed for scanning and transmission electron microscopy. The mitochondrial rich cells fractional area and density in the gill epithelia were determinated. The under scanning electron microscopy （SEM） in 0%0 salinity group reveal changes in the apical ridge of mitochondrial rich cells （MRCs）. In all other groups, the observations revealed numerous crypts disposed mainly in the filament epithelia. In transmission electron microscopy （TEM） two distinct types of MRCs were observed. The data of MRCFA and density revealed in 0%0 and 16%0 values significantly elevated in comparison to 32%0. Despite these lower values, the density in the gill epithelia was higher. The main differences found between the groups revealed that fish exposed to 16%o salinity have less MRCs aperture to the environment and are less related to ion regulation process.展开更多
The effects of salinity on hemolymph osmotic pressure, Na+ concentration and Na+-K+-ATPase activity of gill of Chinese crab Eriocheir sinensis were studied. The results showed that hemolymph osmotic pressure and Na+ c...The effects of salinity on hemolymph osmotic pressure, Na+ concentration and Na+-K+-ATPase activity of gill of Chinese crab Eriocheir sinensis were studied. The results showed that hemolymph osmotic pressure and Na+ concentration increased signifi- cantly (P<0.05), and the Na+-K+-ATPase activity of gills decreased significantly (P<0.05) when salinity increased from 0 to 16. The hemolymph osmotic pressure and Na+ concentration in each treatment group rose remarkably at 0.125 d or 0.25 d, while the Na+-K+-ATPase activity of gill reduced gradually with increased experiment time in 3 d. Then the three parameters remained at a constant level after 0.25 d, 0.125 d and 3 d, respectively, and higher hemolymph osmotic pressure, higher Na+ concentration and lower Na+-K+-ATPase activity of gill occurred at higher salinity. The effect of salinity change on protein concentration of hemolymph was indistinct (P>0.05); However, the protein concentration decreased gradually with the increase of salinity from 0.25 d to 1 d, and then tended to be stable from day 1 to day 15.展开更多
Adhesion of Vibrio alginolyticus to the gill mucus of Pseudosciaena crocea has been investigated using [ methyl-^3 H ] thymidine as isotope tracer. The results showed that： the adhesive quantity of V. alginolyticus i...Adhesion of Vibrio alginolyticus to the gill mucus of Pseudosciaena crocea has been investigated using [ methyl-^3 H ] thymidine as isotope tracer. The results showed that： the adhesive quantity of V. alginolyticus increased with bacterial concentrations and reached equilibrium after incubated for 180 min; the higher adhesive quantity was obtained at 15 ~ 30 ℃ and sourish conditions; adhesion of V. alginolyticus could not achieved without Na^＋ , and Ca^2＋ played an auxiliary role in the bacterial adhesion; adhesion of V. alginolyticus was inhibited remarkably by starvation, heat treatment and periodic acid treatment; all of the eight kinds of carbohydrates investigated enhanced the adhesion of V. alginolyticus to the gill mucus of P. crocea, among them, glucose, mannose, fructose and maltose showed the specially enhanced adhesion. The results indicated that E alginolyticus could adhere to the gill mucus of P. crocea facilely in seawater, and this bacterial adhesion was influenced by environmental factors and closely related to superficial carbohydrate structures and some heat-sensitive structures.展开更多
Until recently, little was known about the fungi found in shark gills and their biomedicinal potential. In this article, we described the isolation, bioactivity, diversity, and secondary metabolites of bioactive fungi...Until recently, little was known about the fungi found in shark gills and their biomedicinal potential. In this article, we described the isolation, bioactivity, diversity, and secondary metabolites of bioactive fungi from the gill of a shark （Carcharodon carcharias）. A total of 115 isolates were obtained and grown in 12 culture media. Fifty-eight of these isolates demonstrated significant activity in four antimicrobial, pesticidal, and cytotoxic bioassay models. Four randomly selected bioactive isolates inhibited human cancer cell proliferation during re-screening. These active isolates were segregated into 6 genera using the internal transcribed spacer-large subunit （ITS-LSU） rDNA-sequence BLAST comparison. Four genera, Penicillium, Aspergillus, Mucor, and Chaetomium were the dominant taxa. A phylogenic tree illustrated their intergenera and intragenera genetic diversity. HPLC-DAD-HRMS analysis and subsequent database searching revealed that nine representative strains produced diverse bioactive compound profiles. These results detail the broad range of bioactive fimgi found in a shark＇s gills, revealing their biopharmaceutical potential. To the best of our knowledge, this is the first study characterizing shark gill fungi and their bioactivity.展开更多
Based on the biological prototype characteristics of shark’s gill jet orifice,the flexible driving characteristics of ionic exchange polymer metal composites(IPMC)artificial muscle materials and the use of sleeve fle...Based on the biological prototype characteristics of shark’s gill jet orifice,the flexible driving characteristics of ionic exchange polymer metal composites(IPMC)artificial muscle materials and the use of sleeve flexible connector,the IPMC linear driving unit simulation model is built and the IPMC material-driving dynamic control structure of bionic gill unit is developed.Meanwhile,through the stress analysis of bionic gill plate and the motion simulation of bionic gill unit,it is verified that various dynamic control and active control of the jet orifice under the condition of different mainstream field velocities will be taken by using IPMC material-driving.Moreover,the large-deflection deformation of bionic gill plate under dynamic pressure and the comparative analysis with that of a rigid gill plate is studied,leading to the achievement of approximate revised modifier from real value to theoretical value of the displacement control of IPMC.展开更多
Flounder gill （FG） cells were used to isolate lymphocystis disease virus （LCDV） and two monoclonal antibodies （Mabs） （1A8 and 3G3） against LCDV were used to trace LCDV infection to FG cells. FG monolayer cells...Flounder gill （FG） cells were used to isolate lymphocystis disease virus （LCDV） and two monoclonal antibodies （Mabs） （1A8 and 3G3） against LCDV were used to trace LCDV infection to FG cells. FG monolayer cells was inoculated with LCDV supernatant, obtained from lymphocystis cells of diseased flounder, Paralichthys olivaceus. LCDV infection was detected with Mabs employing immunocytochemical assay （ICA） and indirect immunofluorescence assay test （IIFAT） technique. Detected by IIFAT, they were specifie for LCDV. The results of experimental infection illustrated that FG cells was sensitive to LCDV, and showed virus-infection positive detected by ICA. Cytopathic effect （CPE） occurred 1-2 days post inoculation （PI）, and half tissue culture infection dosage （TCID50） of vires supematant was 2^2.57 per 40μl. Tracing by IIFAT showed that LCDV positive signal first appeared at the cell membrane immediately PI, and then in cytoplasm at 24h PI, it reached the strongest positive at 48-72 h PI, and began to decrease at 96h PI.展开更多
The fingerling Grass carp. Ctenopharyngodon idellus. was exposed in differentconcentrations of meothrin nearby 24h LC_(50) and its gill morphology was examined by light and elec-tron microscopy. The results indicate...The fingerling Grass carp. Ctenopharyngodon idellus. was exposed in differentconcentrations of meothrin nearby 24h LC_(50) and its gill morphology was examined by light and elec-tron microscopy. The results indicate that meothrin caused fish convulsions. cough, ataxia,intermittent paralysis and overtumed. Morphological examination revealved severe alterations to com-pare with control fish. These initially consisted in hypertrophy of the secondary lamellae, andfinally resulted in local telangiectasia, fusion between secondary lamellae.Ultrustiuctural changes in the gills showed the pillar cell system collapse and resulted in largenon-tissue spaces which were invaded by leucocytes. The cytoplasin of the epithelial cells appearedmany myelin figures, electron dense deposits. Chloride cells were severely damaged with a degeneratedmitochondria and nuclear membrane. Higher concentration of meothrin caused a loss of adhesion be-tween the epithelial cells. accompanied by a collapsing of the structural integrity of the primarylamellae and degenerating of epithelial and chloride cells .展开更多
In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill （FG） cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was ...In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill （FG） cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was determined with methods including MTT and neutral red uptaking （NRU）, lactate dehydrogenase （LDH） releasing and Hoechst 33342 and propidiurn idodide （PI） double staining. Moderate cytotoxicity in a concentration-dependent manner was observed. The 24h-IC50 value of 53.48 ± 1.21, 59.13 ± 1.19 and 46.21 ± 1.24 mgL 1 carbaryl was obtained through MTT, NRU and LDH assays, respectively. Double fluorescence staining dem- onstrated that carbaryl induced the death of FG cells mainly through necrosis. There was no significant genotoxicity found in the FG cells exposed to the highest testing concentration of carbaryl （20mgL-1, P〉0.05） as was demonstrated by Comet assay. Zebrafish embryos exposed to carbaryl at concentrations 〉10 mg L-1 displayed moderate toxic effects on the survival, spontaneous movement, hatching, heart rates of the embryos and their development, which were evidenced by yolk and pericardial sac edemas, body length reduction and tail flexure in time- and concentration-dependent manners at specific stages. The 24h-, 48h- and 96h-LC50 values of carbaryl to zebra fish embryos were 41.80 ± 1.10, 17.80 ± 1.04 and 14.46 ± 1.05 mg L-1, respectively. These results suggested that car- baryl is moderately toxic to FG ceils cultured in vitro and zebrafish embryos, and the FG cells were similar to zebrafish embryos in their sensitivity to carbaryl as 24h-IC50 and LC50 indicated.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
由玛萨诸塞州技术学院(Massachusetts Institute of Technology)应用数学教授Greenspan Harvey P.等编写的高等数学教材名为《微积分——应用数学导论》(1986年第二版)。全书共八章,依次为极限、微分、积分、级数、向量、偏导数、重积...由玛萨诸塞州技术学院(Massachusetts Institute of Technology)应用数学教授Greenspan Harvey P.等编写的高等数学教材名为《微积分——应用数学导论》(1986年第二版)。全书共八章,依次为极限、微分、积分、级数、向量、偏导数、重积分、向量运算。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
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.
文摘Fish gill is a multifunctional organ with role in acid-base balance, elimination of nitrogen waste and mainly gas exchange and ion regulation. There is a high energetic coast for ionregulation in freshwater fish maintained in salt water but a raise in growing taxes was observed for some species. The freshwater Nile tilapia, Oreochromis niloticus, is widely used in aquaculture farmers and the aim of this study was to investigate the changes on the gill filaments nltrastructure in fish kept under different salinities. Alevins were obtained and transported to laboratory of studies in animal stress Federal University of Paran~. Established groups in 0%0, 16%0 and 32%0 salt water with 12 animals in each one. After 30 days of exposition, the animals were anesthetized and the second gill arches were dissected and processed for scanning and transmission electron microscopy. The mitochondrial rich cells fractional area and density in the gill epithelia were determinated. The under scanning electron microscopy （SEM） in 0%0 salinity group reveal changes in the apical ridge of mitochondrial rich cells （MRCs）. In all other groups, the observations revealed numerous crypts disposed mainly in the filament epithelia. In transmission electron microscopy （TEM） two distinct types of MRCs were observed. The data of MRCFA and density revealed in 0%0 and 16%0 values significantly elevated in comparison to 32%0. Despite these lower values, the density in the gill epithelia was higher. The main differences found between the groups revealed that fish exposed to 16%o salinity have less MRCs aperture to the environment and are less related to ion regulation process.
文摘The effects of salinity on hemolymph osmotic pressure, Na+ concentration and Na+-K+-ATPase activity of gill of Chinese crab Eriocheir sinensis were studied. The results showed that hemolymph osmotic pressure and Na+ concentration increased signifi- cantly (P<0.05), and the Na+-K+-ATPase activity of gills decreased significantly (P<0.05) when salinity increased from 0 to 16. The hemolymph osmotic pressure and Na+ concentration in each treatment group rose remarkably at 0.125 d or 0.25 d, while the Na+-K+-ATPase activity of gill reduced gradually with increased experiment time in 3 d. Then the three parameters remained at a constant level after 0.25 d, 0.125 d and 3 d, respectively, and higher hemolymph osmotic pressure, higher Na+ concentration and lower Na+-K+-ATPase activity of gill occurred at higher salinity. The effect of salinity change on protein concentration of hemolymph was indistinct (P>0.05); However, the protein concentration decreased gradually with the increase of salinity from 0.25 d to 1 d, and then tended to be stable from day 1 to day 15.
基金This study was funded by the National Hi-Tech Development Plan("863"Plan)of China under contract Nos 2001AA5070 and 2002AA639600the Natural Science Foundation of Fujian Province under contract No.B0410022.
文摘Adhesion of Vibrio alginolyticus to the gill mucus of Pseudosciaena crocea has been investigated using [ methyl-^3 H ] thymidine as isotope tracer. The results showed that： the adhesive quantity of V. alginolyticus increased with bacterial concentrations and reached equilibrium after incubated for 180 min; the higher adhesive quantity was obtained at 15 ~ 30 ℃ and sourish conditions; adhesion of V. alginolyticus could not achieved without Na^＋ , and Ca^2＋ played an auxiliary role in the bacterial adhesion; adhesion of V. alginolyticus was inhibited remarkably by starvation, heat treatment and periodic acid treatment; all of the eight kinds of carbohydrates investigated enhanced the adhesion of V. alginolyticus to the gill mucus of P. crocea, among them, glucose, mannose, fructose and maltose showed the specially enhanced adhesion. The results indicated that E alginolyticus could adhere to the gill mucus of P. crocea facilely in seawater, and this bacterial adhesion was influenced by environmental factors and closely related to superficial carbohydrate structures and some heat-sensitive structures.
基金Supported by the National Natural Science Foundation of China(No.20902009)the National Science Foundation for Post-Doctoral Scientists of China(Nos.2011M500051,2012T50258)+2 种基金the Yang Fan Scarce Top Talent Project of Guangdong Province(to ZHANG Yi)the Program for Scientific Research Start-up Funds of Guangdong Ocean University(GDOU)(to ZHANG Yi)the Natural Science Research Project of GDOU(No.C14519)
文摘Until recently, little was known about the fungi found in shark gills and their biomedicinal potential. In this article, we described the isolation, bioactivity, diversity, and secondary metabolites of bioactive fungi from the gill of a shark （Carcharodon carcharias）. A total of 115 isolates were obtained and grown in 12 culture media. Fifty-eight of these isolates demonstrated significant activity in four antimicrobial, pesticidal, and cytotoxic bioassay models. Four randomly selected bioactive isolates inhibited human cancer cell proliferation during re-screening. These active isolates were segregated into 6 genera using the internal transcribed spacer-large subunit （ITS-LSU） rDNA-sequence BLAST comparison. Four genera, Penicillium, Aspergillus, Mucor, and Chaetomium were the dominant taxa. A phylogenic tree illustrated their intergenera and intragenera genetic diversity. HPLC-DAD-HRMS analysis and subsequent database searching revealed that nine representative strains produced diverse bioactive compound profiles. These results detail the broad range of bioactive fimgi found in a shark＇s gills, revealing their biopharmaceutical potential. To the best of our knowledge, this is the first study characterizing shark gill fungi and their bioactivity.
基金Project(51275102)supported by the National Natural Science Foundation of ChinaProject(HEUCF140713)supported by the Fundamental Research Funds for the Central Universities,China
文摘Based on the biological prototype characteristics of shark’s gill jet orifice,the flexible driving characteristics of ionic exchange polymer metal composites(IPMC)artificial muscle materials and the use of sleeve flexible connector,the IPMC linear driving unit simulation model is built and the IPMC material-driving dynamic control structure of bionic gill unit is developed.Meanwhile,through the stress analysis of bionic gill plate and the motion simulation of bionic gill unit,it is verified that various dynamic control and active control of the jet orifice under the condition of different mainstream field velocities will be taken by using IPMC material-driving.Moreover,the large-deflection deformation of bionic gill plate under dynamic pressure and the comparative analysis with that of a rigid gill plate is studied,leading to the achievement of approximate revised modifier from real value to theoretical value of the displacement control of IPMC.
文摘Flounder gill （FG） cells were used to isolate lymphocystis disease virus （LCDV） and two monoclonal antibodies （Mabs） （1A8 and 3G3） against LCDV were used to trace LCDV infection to FG cells. FG monolayer cells was inoculated with LCDV supernatant, obtained from lymphocystis cells of diseased flounder, Paralichthys olivaceus. LCDV infection was detected with Mabs employing immunocytochemical assay （ICA） and indirect immunofluorescence assay test （IIFAT） technique. Detected by IIFAT, they were specifie for LCDV. The results of experimental infection illustrated that FG cells was sensitive to LCDV, and showed virus-infection positive detected by ICA. Cytopathic effect （CPE） occurred 1-2 days post inoculation （PI）, and half tissue culture infection dosage （TCID50） of vires supematant was 2^2.57 per 40μl. Tracing by IIFAT showed that LCDV positive signal first appeared at the cell membrane immediately PI, and then in cytoplasm at 24h PI, it reached the strongest positive at 48-72 h PI, and began to decrease at 96h PI.
文摘The fingerling Grass carp. Ctenopharyngodon idellus. was exposed in differentconcentrations of meothrin nearby 24h LC_(50) and its gill morphology was examined by light and elec-tron microscopy. The results indicate that meothrin caused fish convulsions. cough, ataxia,intermittent paralysis and overtumed. Morphological examination revealved severe alterations to com-pare with control fish. These initially consisted in hypertrophy of the secondary lamellae, andfinally resulted in local telangiectasia, fusion between secondary lamellae.Ultrustiuctural changes in the gills showed the pillar cell system collapse and resulted in largenon-tissue spaces which were invaded by leucocytes. The cytoplasin of the epithelial cells appearedmany myelin figures, electron dense deposits. Chloride cells were severely damaged with a degeneratedmitochondria and nuclear membrane. Higher concentration of meothrin caused a loss of adhesion be-tween the epithelial cells. accompanied by a collapsing of the structural integrity of the primarylamellae and degenerating of epithelial and chloride cells .
基金supported by the grants from National High-tech R&D Program of China (863 Program, Grant No. 2012AA 10A402)National Natural Science Foundation of China (Grant Nos. 31172391 and 31472274)+1 种基金Key Laboratory Open Foundation of Marine Bioactive Substances and Modern Analytical Technology, State Oceanic Administration (No. MBSMAT-2011-01)Fundamental Research Funds for the Central Universities of China (Grant No. 201122005)
文摘In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill （FG） cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was determined with methods including MTT and neutral red uptaking （NRU）, lactate dehydrogenase （LDH） releasing and Hoechst 33342 and propidiurn idodide （PI） double staining. Moderate cytotoxicity in a concentration-dependent manner was observed. The 24h-IC50 value of 53.48 ± 1.21, 59.13 ± 1.19 and 46.21 ± 1.24 mgL 1 carbaryl was obtained through MTT, NRU and LDH assays, respectively. Double fluorescence staining dem- onstrated that carbaryl induced the death of FG cells mainly through necrosis. There was no significant genotoxicity found in the FG cells exposed to the highest testing concentration of carbaryl （20mgL-1, P〉0.05） as was demonstrated by Comet assay. Zebrafish embryos exposed to carbaryl at concentrations 〉10 mg L-1 displayed moderate toxic effects on the survival, spontaneous movement, hatching, heart rates of the embryos and their development, which were evidenced by yolk and pericardial sac edemas, body length reduction and tail flexure in time- and concentration-dependent manners at specific stages. The 24h-, 48h- and 96h-LC50 values of carbaryl to zebra fish embryos were 41.80 ± 1.10, 17.80 ± 1.04 and 14.46 ± 1.05 mg L-1, respectively. These results suggested that car- baryl is moderately toxic to FG ceils cultured in vitro and zebrafish embryos, and the FG cells were similar to zebrafish embryos in their sensitivity to carbaryl as 24h-IC50 and LC50 indicated.
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.
