Dissolved oxygen(DO)is one of most important factors which affect wide range physiologic features of including immune responses and intestinal bacterial community.However,the underlying mechanisms remain enigmatic.To ...Dissolved oxygen(DO)is one of most important factors which affect wide range physiologic features of including immune responses and intestinal bacterial community.However,the underlying mechanisms remain enigmatic.To address this question,the intestinal bacterial community compositions and the immune features of Atlantic salmon(Salmo salar)grown in recirculating aquaculture systems(RAS)were characterized.Fish were reared under different DO saturation levels,e.g.,200% saturation named high group(H),100%saturation named control group(CK),and 60%saturation named lower group(L).Large variations in the operational taxonomic units(OTUs)frequency distribution for the intestinal bacterial community of Atlantic salmon were observed.The intestinal bacterial community of all groups was dominated mainly by three phyla,e.g.,Proteobacteria.Firmicutes,and Bacteroidetes.Interestingly,Acinetobacter baumannii,an opportunistic pathogen of salmon was increased significantly in L group.We further monitored the immunity features of fish under different DO levels.The results show that leucocyte number,cortisol level,the expressions of interleukin-1β(IL-1β),Toll-like receptor 4(TLR4),and nucleotide-binding oligomerization domain like protein 2(NOD2)were higher at significant levels in the L group than those in the other two groups.TLR4 and NOD2 are usually related with the bacterial infections;therefore,it is reasonable to believe that the stronger immune responses observed in the L group might be related with the higher abundance of A.baumannii in the inte stine of Atlantic salmon.Overall,these findings demonstrated that low DO level may induce stronger immunity responses in Atlantic salmon.展开更多
The contamination of Atlantic salmon with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has impeded the development of the cold-chain food industry and posed possible risks to the population.Electron beam...The contamination of Atlantic salmon with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has impeded the development of the cold-chain food industry and posed possible risks to the population.Electron beam(E-beam)irradiation under 2,4,7,and 10 kGy can effectively inactivate SARS-CoV-2 in cold-chain seafood.However,there are few statistics about the quality changes of salmon exposed to these irradiation dosages.This work demonstrated that E-beam irradiation at dosages capable of killing SARS-CoV-2 induced lipid oxidation,decreased vitamin A content,and increased some amino acids and ash content.In addition,irradiation altered the textural features of salmon,such as its hardness,resilience,cohesiveness,and chewiness.The irradiation considerably affected the L*,a*,and b*values of salmon,with the L*value increasing and a*,b*values decreasing.There was no significant difference in the sensory evaluation of control and irradiated salmon.It was shown that irradiation with 2−7 kGy E-beam did not significantly degrade quality.The inactivation of SARS-CoV-2 in salmon is advised at a dose of 2 kGy.展开更多
The objective of this study was to investigate the effect of gelatin(SG) isolated from salmon skin and its hydrolysate(SGH) on photoaging skin, and the mechanism responsible for anti-photoaging. The average molecular ...The objective of this study was to investigate the effect of gelatin(SG) isolated from salmon skin and its hydrolysate(SGH) on photoaging skin, and the mechanism responsible for anti-photoaging. The average molecular weights of SG and SGH were 65 k Da and 873 Da, respectively. The amino acid compositions of SG and SGH were similar. Both of them were abundant in hydrophobic amino acids. Twenty-five peptides were identified from SGH. SG and SGH could improve UV irradiation-induced pathological changes of macroscopical tissue texture and skin morphology. Hydroxyproline content is an indicator of matrix collagen content, SG and SGH could inhibit the decrease of hydroxyproline content in photoaging skin in a dose dependent manner. In addition, SG and SGH could alleviate UV irradiation-induced oxidative damages to skin by increasing the activities of total superoxide dismutase(T-SOD), glutathione peroxidase(GSH-Px) and catalase(CAT), increasing the content of glutathione(GSH) and decreasing the content of malonaldehyde(MDA). Moreover, SG and SGH could enhance immune regulation system by increasing the thymus index. Thus, the anti-photoaging mechanisms of SG and SGH were by inhibiting the depletion of antioxidant defense components, involving in the synthesis of collagen and enhancing the function of immune system. Besides, SGH showed a better result in protecting skin from photoaging than SG.展开更多
The present study sampled the intestinal content of healthy and unhealthy Atlantic salmon( Salmo salar L.), the ambient water of unhealthy fish, and the biofilter material in the recirculating aquaculture system(RAS) ...The present study sampled the intestinal content of healthy and unhealthy Atlantic salmon( Salmo salar L.), the ambient water of unhealthy fish, and the biofilter material in the recirculating aquaculture system(RAS) to understand differences in the intestinal microbiota. The V4–V5 regions of the prokaryotic 16 S r RNA genes in the samples were analyzed by Mi Seq high-throughput sequencing. The fish were adults with no differences in body length or weight. Representative members of the intestinal microbiota were identified. The intestinal microbiota of the healthy fishincluded Proteobacteria(44.33%), Actinobacteria(17.89%), Bacteroidetes(15.25%), and Firmicutes(9.11%), among which the families Micrococcaceae and Oxalobacteraceae and genera S phingomonas, Streptomyces, Pedobacter, Janthinobacterium, Burkholderia, and Balneimonas were most abundant. Proteobacteria(70.46%), Bacteroidetes(7.59%), and Firmicutes(7.55%) dominated the microbiota of unhealthy fish, and Chloroflexi(2.71%), and Aliivibrio and Vibrio as well as genera in the family Aeromonadaceae were most strongly represented. Overall, the intestinal hindgut microbiota differed between healthy and unhealthy fish. This study off ers a useful tool for monitoring the health status of fish and for screening the utility of probiotics by studying the intestinal microbiota.展开更多
Atlantic salmon reared in recirculating aquaculture system(RAS) may lead to inappropriately high stocking density, because ?sh live in a limited space. Finding the suitable stocking density of Atlantic salmon reared i...Atlantic salmon reared in recirculating aquaculture system(RAS) may lead to inappropriately high stocking density, because ?sh live in a limited space. Finding the suitable stocking density of Atlantic salmon reared in RAS is very important for RAS industry. In this paper, the in?uence of stocking density on growth and some stress related physiological factors were investigated to evaluate the ef fects of stocking density. The ?sh were reared for 220 days at ?ve densities(A: 24 kg/m^3; B: 21 kg/m^3; C: 15 kg/m^3; D: 9 kg/m^3 and E: 6 kg/m^3). The results show that 30 kg/m^3 might be the maximum density which RAS can af ford in China. The stocking densities under 30 kg/m^3 have no ef fect on mortality of Atlantic salmon reared in RAS. However, the speci?c growth rate(SGR), ?nal weight and weight gain in the high density group were signi?cantly lower than the lower density groups and middle density groups. Moreover, feed conversion rate(FCR) had a negative correlation with density. Plasma hormone T_3 and GH showed signi?cant decrease with the increase of the stocking density of the experiment. Furthermore, thyroid hormone(T 3), GH(growth hormone) activities were decreased with stocking density increase. However, plasma cortisol, GOT(glutamic oxalacetic transaminase) and GPT(glutamic pyruvic transaminase) activities were increase with stocking density increase. And the stocking density has no ef fects on plasma lysozyme of Atlantic salmon reared in RAS. These investigations would also help devise effcient ways to rear adult Atlantic salmon in China and may, in a way, help spread salmon mariculture in China.展开更多
Juvenile landlocked Chinook salmon (Oncorhynchus tshawytscha) (mean ± SD initial weight 2.6 ± 0.7 g, fork length 6.3 ± 0.5) were reared in three different water velocities [0.5, 1.5 and 3.0 body length/...Juvenile landlocked Chinook salmon (Oncorhynchus tshawytscha) (mean ± SD initial weight 2.6 ± 0.7 g, fork length 6.3 ± 0.5) were reared in three different water velocities [0.5, 1.5 and 3.0 body length/s (BL/s)] for four weeks to determine possible effects of water velocity on growth, condition, and survival. Fish were sampled for weight, fork length, condition factor, hepatosomatic index (HSI), viscerosomatic index (VSI), and fin erosion after four weeks of feeding to satiation. At the end of the feeding trial, the fish were handled and transported to simulate stocking, with survival observed over the following 10 d. Following four weeks of feeding, fish reared in 0.5 and 1.5 BL/s had the same growth and food conversion ratio, but fish reared at 3.0 BL/s had a significant reduction in both metrics. Furthermore, fish reared at 1.5 BL/s had a significantly higher condition factor than fish reared in other treatments. No significant differences were found for HSI, VSI, fin erosion, or survival. The results from this study indicate that a moderate velocity (1.5 BL/s), which is necessary for circular tanks to be self-cleaning, is not detrimental to fish growth or condition, but a faster water velocity (3.0 BL/s) negatively affects fish growth and food utilization.展开更多
In order to assess the effect of enhancement release of chum salmon(Oncorhynchus keta),otolith strontium(Sr)marking method was used to tag chum salmon released in Tangwang River in 2016.The homing chum salmon were det...In order to assess the effect of enhancement release of chum salmon(Oncorhynchus keta),otolith strontium(Sr)marking method was used to tag chum salmon released in Tangwang River in 2016.The homing chum salmon were detected and the samples were collected in Tangwang River,Ussuri River and Suifen River in the autumn of2018.The samples were analyzed by examining Sr and calcium(Ca)fingerprints in the otolith using electron probe microanalysis.The results suggested that two samples collected in Tangwang River had the marking ring near the core of otolith where the Sr concentration and Sr/Ca ratio were significantly higher than comparative samples.Proving that the two fish belonged to the released population in Tangwang River in 2016.This article indicated the success of the enhancement release of chum salmon from the Tangwang River for the first time and also confirmed the validity of Sr marking in enhancement release of fishes.展开更多
Several treatment options have been developed to minimize the spread of zebra mussel Dreissena polymorphaveligers (larvae) during fish transportation. However, the effect of these treatments on the survival of newly-f...Several treatment options have been developed to minimize the spread of zebra mussel Dreissena polymorphaveligers (larvae) during fish transportation. However, the effect of these treatments on the survival of newly-fertilized salmonid eggs has not been evaluated. This study examined the survival of water-hardened landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs after one of four different treatments: 1) Control (no chemicals), 2) 100 mg/L formalin for two hours, 3) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for two hours, and 4) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for three hours. The 100 mg/L formalin treatment produced complete egg mortality. Survival to hatch was not significantly different among the other three treatments. Based on these results, the use of 750 mg/L potassium chloride for one hour followed by 20 mg/L formalin for three hours is recommended when moving Chinook salmon eggs from waters potentially infested with zebra mussels to hatcheries for incubation.展开更多
Secondary structure of [Val. Ala]sCT- an analog of salmon calcitonin (sCT) not containing an N-terminal disultide bridge. was investigated by circular dichroism (CD) and Fourier-transform intrared spectroscopy (FTIR) ...Secondary structure of [Val. Ala]sCT- an analog of salmon calcitonin (sCT) not containing an N-terminal disultide bridge. was investigated by circular dichroism (CD) and Fourier-transform intrared spectroscopy (FTIR) methods. Both CD and FTIR results show that the main contbrmational structure of [Val Ala']sCT in aqueous solution is random coil structure. while in trifluorethanol (TFE) it displays a strong α-helical structure. The relationship between the biological activity and the conformational structure of [Val, Ala] sCT is als0 discussed.展开更多
Peptide analogs of salmon calcitonin (sCT) were synthesized by using Fmoc-based chemistry on MBHA resins. Salmon calcitonin was modified by 1) cysteines at positions 1 and 7 were replaced by valine and alanine respect...Peptide analogs of salmon calcitonin (sCT) were synthesized by using Fmoc-based chemistry on MBHA resins. Salmon calcitonin was modified by 1) cysteines at positions 1 and 7 were replaced by valine and alanine respectively to result in open chain analogs, 2) the glycine at position 30 was replaced by alanine, D-alanine and sarcosine respectively, and 3) some residues were deleted besides the above two modifications. A modified two-step deprotection / cleavage procedure, in which a solvent of TFA / TMSBr / thioanisole / EDT / m-cresol combines with HF cleavage, was adopted in SPPS.展开更多
In this mini review, we systematized current knowledge about the number of Caligus elongatus on farmed Atlantic salmon in relation to the use of lumpfish as cleaner fish. The review was prompted by reports of an unusu...In this mini review, we systematized current knowledge about the number of Caligus elongatus on farmed Atlantic salmon in relation to the use of lumpfish as cleaner fish. The review was prompted by reports of an unusually large number of sea lice(C. elongatus) infestation of farmed salmon in northern Norway, Faroese Islands and Iceland and the urgent need to determine if common lumpfish can be used to reduce the number on farmed Atlantic salmon by actively grazing on sea lice. Available data from Norway clearly indicate that lumpfish grazes on C. elongatus, and it is possible to enhance this grazing with the assistances of livefeed conditioning prior to sea pen transfer and selective breeding. Observations from Iceland, Faroese Islands and Scotland also indicate that lumpfish can effectively lower infestations of C. elongatus on salmon. Overall, this mini review expresses that lumpfish can actively lower the number of C. elongatus on farmed Atlantic salmon.展开更多
Atlantic salmon (Salmo salar) returns to rivers in Ireland have fallen in the last decade resulting in the dramatic closure or curtailment of traditional fisheries. Concerns that stocks were slow to recover prompted f...Atlantic salmon (Salmo salar) returns to rivers in Ireland have fallen in the last decade resulting in the dramatic closure or curtailment of traditional fisheries. Concerns that stocks were slow to recover prompted further investigation of all factors believed to impact on salmon. In examining geographic and temporal trends in Atlantic salmon stock abundance at a River Basin District level, the effect of salmon aquaculture sites and freshwater habitat quality as potential drivers of stock abundance are evaluated. This study found no correlation between the presence of aquaculture and the performance of adjacent wild salmon stocks. Freshwater habitat quality was found to have a highly significant correlation with stock status, suggesting that it may be a key driver, implicated in the survival of individual stocks.展开更多
Delayed fertilization of salmonid eggs can be a useful option to enhance the efficiency of artificial spawning operations. This experiment examined the fertility of landlocked fall Chinook salmon (Oncorhynchus tshawyt...Delayed fertilization of salmonid eggs can be a useful option to enhance the efficiency of artificial spawning operations. This experiment examined the fertility of landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs stored for various times after removal from female broodstock. Fertilization occurred either immediately after spawning or the eggs were stored with oxygen at 11°C and fertilized at 4, 6, 8, 12, or 20 hours post-spawn. Survival to the eyed stage of egg development was significantly greater in the eggs fertilized immediately or after four, six, or eight hours of storage compared to those eggs stored for 12 or 20 hours prior to fertilization (P = 0.024). Survival to hatch was also significantly different (P = 0.018) and followed the same pattern. This study is the first to document the successful fertilization of landlocked fall Chinook salmon eggs after eight hours of storage.展开更多
The effect of different carbohydrate-to-lipid ratios in feeds on the growth performance and organosomatic indices of Atlantic salmon, Salmon salar, was determined in this experiment. Four iso- energetic feeds were man...The effect of different carbohydrate-to-lipid ratios in feeds on the growth performance and organosomatic indices of Atlantic salmon, Salmon salar, was determined in this experiment. Four iso- energetic feeds were manufactured with increasing carbohydrate level (18%, 21%, 14%, 26%). Lipid level was decreasing from 14% to 11% for each diet for energetic balance. Fish were reared in triplicate tanks for each diet treatment for 49 days. The diet which contained 26% carbohydrate and 11% lipid provided the highest specific growth rate (SGR = 0.66% ± 0.04% per day) to the fish. However, the feed efficiency (FER) ranked from 0.71 to 0.91 had no significant differences between diets. Similarly, the values of condition index (K), relative gut length (RGL) and hepatosomatic index (HSI) had no significant differences between groups. The relationship between liver and carcass weight showed that with the increasing of fish carcass weight, the liver weight increased. According to this experiment, it suggests that based on an optimum level of carbohydrate in diet, the juvenile salmon has a better growth fed by a diet with a higher carbohydrate-to-lipid ratio.展开更多
基金Supported by the Shandong Province Key Research and Invention Program(No.2017CXGC010K)the China Agriculture Research System(No.CARS-47)+7 种基金the National Key Research and Development Program(No.2018YFD0901204)the National Infrastructure of Fishery Germplasm Resource(No.2019DKA30470)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0502-2)the National Natural Science Foundation of China(Nos.31872606,31572657,U1701233,31402283,31802319)the Department of Agriculture and Rural Areas of Guangdong Province(No.KA1911101)the Natural Science Foundation of Shandong Province(No.ZR2018BC053)the Agricultural Application Technology Innovation Project of Shandong Province in 2018/2019(No.SD2019YY011)the Shandong Province Major Scientific and Technological Innovation Projects(No.2019JZZY020710)。
文摘Dissolved oxygen(DO)is one of most important factors which affect wide range physiologic features of including immune responses and intestinal bacterial community.However,the underlying mechanisms remain enigmatic.To address this question,the intestinal bacterial community compositions and the immune features of Atlantic salmon(Salmo salar)grown in recirculating aquaculture systems(RAS)were characterized.Fish were reared under different DO saturation levels,e.g.,200% saturation named high group(H),100%saturation named control group(CK),and 60%saturation named lower group(L).Large variations in the operational taxonomic units(OTUs)frequency distribution for the intestinal bacterial community of Atlantic salmon were observed.The intestinal bacterial community of all groups was dominated mainly by three phyla,e.g.,Proteobacteria.Firmicutes,and Bacteroidetes.Interestingly,Acinetobacter baumannii,an opportunistic pathogen of salmon was increased significantly in L group.We further monitored the immunity features of fish under different DO levels.The results show that leucocyte number,cortisol level,the expressions of interleukin-1β(IL-1β),Toll-like receptor 4(TLR4),and nucleotide-binding oligomerization domain like protein 2(NOD2)were higher at significant levels in the L group than those in the other two groups.TLR4 and NOD2 are usually related with the bacterial infections;therefore,it is reasonable to believe that the stronger immune responses observed in the L group might be related with the higher abundance of A.baumannii in the inte stine of Atlantic salmon.Overall,these findings demonstrated that low DO level may induce stronger immunity responses in Atlantic salmon.
基金the grants from Hangzhou Global Scientific and Technological Innovation Center of Zhejiang University(KC2021ZY0B0003).
文摘The contamination of Atlantic salmon with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has impeded the development of the cold-chain food industry and posed possible risks to the population.Electron beam(E-beam)irradiation under 2,4,7,and 10 kGy can effectively inactivate SARS-CoV-2 in cold-chain seafood.However,there are few statistics about the quality changes of salmon exposed to these irradiation dosages.This work demonstrated that E-beam irradiation at dosages capable of killing SARS-CoV-2 induced lipid oxidation,decreased vitamin A content,and increased some amino acids and ash content.In addition,irradiation altered the textural features of salmon,such as its hardness,resilience,cohesiveness,and chewiness.The irradiation considerably affected the L*,a*,and b*values of salmon,with the L*value increasing and a*,b*values decreasing.There was no significant difference in the sensory evaluation of control and irradiated salmon.It was shown that irradiation with 2−7 kGy E-beam did not significantly degrade quality.The inactivation of SARS-CoV-2 in salmon is advised at a dose of 2 kGy.
基金supported by the National Natural Science Foundation of China (No.31401476)Specialized Research Fund for the Doctoral Program of Higher Education (No.20130132120024)+1 种基金the Fundamental Research Funds for The Central Universities (No.201313002)Shandong Province Regional Innovation and Development of Marine Economy Demonstration Projects
文摘The objective of this study was to investigate the effect of gelatin(SG) isolated from salmon skin and its hydrolysate(SGH) on photoaging skin, and the mechanism responsible for anti-photoaging. The average molecular weights of SG and SGH were 65 k Da and 873 Da, respectively. The amino acid compositions of SG and SGH were similar. Both of them were abundant in hydrophobic amino acids. Twenty-five peptides were identified from SGH. SG and SGH could improve UV irradiation-induced pathological changes of macroscopical tissue texture and skin morphology. Hydroxyproline content is an indicator of matrix collagen content, SG and SGH could inhibit the decrease of hydroxyproline content in photoaging skin in a dose dependent manner. In addition, SG and SGH could alleviate UV irradiation-induced oxidative damages to skin by increasing the activities of total superoxide dismutase(T-SOD), glutathione peroxidase(GSH-Px) and catalase(CAT), increasing the content of glutathione(GSH) and decreasing the content of malonaldehyde(MDA). Moreover, SG and SGH could enhance immune regulation system by increasing the thymus index. Thus, the anti-photoaging mechanisms of SG and SGH were by inhibiting the depletion of antioxidant defense components, involving in the synthesis of collagen and enhancing the function of immune system. Besides, SGH showed a better result in protecting skin from photoaging than SG.
基金Supported by the National Natural Science Foundation of China(Nos.31472312,41306152,31402283)the Qingdao Innovation Talents Program(No.13-CX-16)+2 种基金the National Key Technology Research and Development Program of China(No.2014BAD08B09)the Earmarked Fund for Modern Agroindustry Technology Research System(No.CARS-48)the Project for International S&T Cooperation Program of China(No.2014DFA31030)
文摘The present study sampled the intestinal content of healthy and unhealthy Atlantic salmon( Salmo salar L.), the ambient water of unhealthy fish, and the biofilter material in the recirculating aquaculture system(RAS) to understand differences in the intestinal microbiota. The V4–V5 regions of the prokaryotic 16 S r RNA genes in the samples were analyzed by Mi Seq high-throughput sequencing. The fish were adults with no differences in body length or weight. Representative members of the intestinal microbiota were identified. The intestinal microbiota of the healthy fishincluded Proteobacteria(44.33%), Actinobacteria(17.89%), Bacteroidetes(15.25%), and Firmicutes(9.11%), among which the families Micrococcaceae and Oxalobacteraceae and genera S phingomonas, Streptomyces, Pedobacter, Janthinobacterium, Burkholderia, and Balneimonas were most abundant. Proteobacteria(70.46%), Bacteroidetes(7.59%), and Firmicutes(7.55%) dominated the microbiota of unhealthy fish, and Chloroflexi(2.71%), and Aliivibrio and Vibrio as well as genera in the family Aeromonadaceae were most strongly represented. Overall, the intestinal hindgut microbiota differed between healthy and unhealthy fish. This study off ers a useful tool for monitoring the health status of fish and for screening the utility of probiotics by studying the intestinal microbiota.
基金Supported by the National Science Foundation for Young Scientists of China(No.31402314,31402283)the Agency of Science and Technology of Shandong Province(No.2013GHY11514)+4 种基金the Modern Agro-Industry Technology Research System(No.nycytx-50)the Scientific and Technology Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology(Nos.2015ASKJ02,2015ASKJ02-03-03)the Youth Innovation Promotion Association CAS,the Chinese Academy of Science and Technology Service Network Planning(No.KFJ-EW-STS-060)the China Agriculture Research System(No.CARS-47)the Shandong Provincial Key S&T Innovation Project(No.2017CXGC0101)
文摘Atlantic salmon reared in recirculating aquaculture system(RAS) may lead to inappropriately high stocking density, because ?sh live in a limited space. Finding the suitable stocking density of Atlantic salmon reared in RAS is very important for RAS industry. In this paper, the in?uence of stocking density on growth and some stress related physiological factors were investigated to evaluate the ef fects of stocking density. The ?sh were reared for 220 days at ?ve densities(A: 24 kg/m^3; B: 21 kg/m^3; C: 15 kg/m^3; D: 9 kg/m^3 and E: 6 kg/m^3). The results show that 30 kg/m^3 might be the maximum density which RAS can af ford in China. The stocking densities under 30 kg/m^3 have no ef fect on mortality of Atlantic salmon reared in RAS. However, the speci?c growth rate(SGR), ?nal weight and weight gain in the high density group were signi?cantly lower than the lower density groups and middle density groups. Moreover, feed conversion rate(FCR) had a negative correlation with density. Plasma hormone T_3 and GH showed signi?cant decrease with the increase of the stocking density of the experiment. Furthermore, thyroid hormone(T 3), GH(growth hormone) activities were decreased with stocking density increase. However, plasma cortisol, GOT(glutamic oxalacetic transaminase) and GPT(glutamic pyruvic transaminase) activities were increase with stocking density increase. And the stocking density has no ef fects on plasma lysozyme of Atlantic salmon reared in RAS. These investigations would also help devise effcient ways to rear adult Atlantic salmon in China and may, in a way, help spread salmon mariculture in China.
文摘Juvenile landlocked Chinook salmon (Oncorhynchus tshawytscha) (mean ± SD initial weight 2.6 ± 0.7 g, fork length 6.3 ± 0.5) were reared in three different water velocities [0.5, 1.5 and 3.0 body length/s (BL/s)] for four weeks to determine possible effects of water velocity on growth, condition, and survival. Fish were sampled for weight, fork length, condition factor, hepatosomatic index (HSI), viscerosomatic index (VSI), and fin erosion after four weeks of feeding to satiation. At the end of the feeding trial, the fish were handled and transported to simulate stocking, with survival observed over the following 10 d. Following four weeks of feeding, fish reared in 0.5 and 1.5 BL/s had the same growth and food conversion ratio, but fish reared at 3.0 BL/s had a significant reduction in both metrics. Furthermore, fish reared at 1.5 BL/s had a significantly higher condition factor than fish reared in other treatments. No significant differences were found for HSI, VSI, fin erosion, or survival. The results from this study indicate that a moderate velocity (1.5 BL/s), which is necessary for circular tanks to be self-cleaning, is not detrimental to fish growth or condition, but a faster water velocity (3.0 BL/s) negatively affects fish growth and food utilization.
基金The Natural Science Foundation of Heilongjiang Province of China under contract No.YQ2019C034the Special Financial Funds of the Ministry of Agriculture and Rural Affairs under contract No.2130135。
文摘In order to assess the effect of enhancement release of chum salmon(Oncorhynchus keta),otolith strontium(Sr)marking method was used to tag chum salmon released in Tangwang River in 2016.The homing chum salmon were detected and the samples were collected in Tangwang River,Ussuri River and Suifen River in the autumn of2018.The samples were analyzed by examining Sr and calcium(Ca)fingerprints in the otolith using electron probe microanalysis.The results suggested that two samples collected in Tangwang River had the marking ring near the core of otolith where the Sr concentration and Sr/Ca ratio were significantly higher than comparative samples.Proving that the two fish belonged to the released population in Tangwang River in 2016.This article indicated the success of the enhancement release of chum salmon from the Tangwang River for the first time and also confirmed the validity of Sr marking in enhancement release of fishes.
文摘Several treatment options have been developed to minimize the spread of zebra mussel Dreissena polymorphaveligers (larvae) during fish transportation. However, the effect of these treatments on the survival of newly-fertilized salmonid eggs has not been evaluated. This study examined the survival of water-hardened landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs after one of four different treatments: 1) Control (no chemicals), 2) 100 mg/L formalin for two hours, 3) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for two hours, and 4) 750 mg/L of potassium chloride for one hour followed by 20 mg/L formalin for three hours. The 100 mg/L formalin treatment produced complete egg mortality. Survival to hatch was not significantly different among the other three treatments. Based on these results, the use of 750 mg/L potassium chloride for one hour followed by 20 mg/L formalin for three hours is recommended when moving Chinook salmon eggs from waters potentially infested with zebra mussels to hatcheries for incubation.
文摘Secondary structure of [Val. Ala]sCT- an analog of salmon calcitonin (sCT) not containing an N-terminal disultide bridge. was investigated by circular dichroism (CD) and Fourier-transform intrared spectroscopy (FTIR) methods. Both CD and FTIR results show that the main contbrmational structure of [Val Ala']sCT in aqueous solution is random coil structure. while in trifluorethanol (TFE) it displays a strong α-helical structure. The relationship between the biological activity and the conformational structure of [Val, Ala] sCT is als0 discussed.
文摘Peptide analogs of salmon calcitonin (sCT) were synthesized by using Fmoc-based chemistry on MBHA resins. Salmon calcitonin was modified by 1) cysteines at positions 1 and 7 were replaced by valine and alanine respectively to result in open chain analogs, 2) the glycine at position 30 was replaced by alanine, D-alanine and sarcosine respectively, and 3) some residues were deleted besides the above two modifications. A modified two-step deprotection / cleavage procedure, in which a solvent of TFA / TMSBr / thioanisole / EDT / m-cresol combines with HF cleavage, was adopted in SPPS.
基金Financial support was given by the Norwegian Seafood Research Found (Nos. KEKS901539 and 901652EFFEKTIV)。
文摘In this mini review, we systematized current knowledge about the number of Caligus elongatus on farmed Atlantic salmon in relation to the use of lumpfish as cleaner fish. The review was prompted by reports of an unusually large number of sea lice(C. elongatus) infestation of farmed salmon in northern Norway, Faroese Islands and Iceland and the urgent need to determine if common lumpfish can be used to reduce the number on farmed Atlantic salmon by actively grazing on sea lice. Available data from Norway clearly indicate that lumpfish grazes on C. elongatus, and it is possible to enhance this grazing with the assistances of livefeed conditioning prior to sea pen transfer and selective breeding. Observations from Iceland, Faroese Islands and Scotland also indicate that lumpfish can effectively lower infestations of C. elongatus on salmon. Overall, this mini review expresses that lumpfish can actively lower the number of C. elongatus on farmed Atlantic salmon.
文摘Atlantic salmon (Salmo salar) returns to rivers in Ireland have fallen in the last decade resulting in the dramatic closure or curtailment of traditional fisheries. Concerns that stocks were slow to recover prompted further investigation of all factors believed to impact on salmon. In examining geographic and temporal trends in Atlantic salmon stock abundance at a River Basin District level, the effect of salmon aquaculture sites and freshwater habitat quality as potential drivers of stock abundance are evaluated. This study found no correlation between the presence of aquaculture and the performance of adjacent wild salmon stocks. Freshwater habitat quality was found to have a highly significant correlation with stock status, suggesting that it may be a key driver, implicated in the survival of individual stocks.
文摘Delayed fertilization of salmonid eggs can be a useful option to enhance the efficiency of artificial spawning operations. This experiment examined the fertility of landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs stored for various times after removal from female broodstock. Fertilization occurred either immediately after spawning or the eggs were stored with oxygen at 11°C and fertilized at 4, 6, 8, 12, or 20 hours post-spawn. Survival to the eyed stage of egg development was significantly greater in the eggs fertilized immediately or after four, six, or eight hours of storage compared to those eggs stored for 12 or 20 hours prior to fertilization (P = 0.024). Survival to hatch was also significantly different (P = 0.018) and followed the same pattern. This study is the first to document the successful fertilization of landlocked fall Chinook salmon eggs after eight hours of storage.
文摘The effect of different carbohydrate-to-lipid ratios in feeds on the growth performance and organosomatic indices of Atlantic salmon, Salmon salar, was determined in this experiment. Four iso- energetic feeds were manufactured with increasing carbohydrate level (18%, 21%, 14%, 26%). Lipid level was decreasing from 14% to 11% for each diet for energetic balance. Fish were reared in triplicate tanks for each diet treatment for 49 days. The diet which contained 26% carbohydrate and 11% lipid provided the highest specific growth rate (SGR = 0.66% ± 0.04% per day) to the fish. However, the feed efficiency (FER) ranked from 0.71 to 0.91 had no significant differences between diets. Similarly, the values of condition index (K), relative gut length (RGL) and hepatosomatic index (HSI) had no significant differences between groups. The relationship between liver and carcass weight showed that with the increasing of fish carcass weight, the liver weight increased. According to this experiment, it suggests that based on an optimum level of carbohydrate in diet, the juvenile salmon has a better growth fed by a diet with a higher carbohydrate-to-lipid ratio.