Environmental enrichment is the incorporation of materials into hatchery tanks to simulate a more natural rearing environment. This study investigated the use of a vertically-suspended plastic conduit array as enrichm...Environmental enrichment is the incorporation of materials into hatchery tanks to simulate a more natural rearing environment. This study investigated the use of a vertically-suspended plastic conduit array as enrichment in 3.63 m circular tanks during Atlantic salmon (Salmo salar) rearing. After 168 days, feed conversion ratio was significantly improved for salmon reared in tanks with enrichment compared to the barren control tanks. Final tank weights and weight gain were not significantly different, although the difference in mean gain of 182.0 kg in the enriched tanks compared to 162.9 kg in the control tanks approached significance. There were no significant differences in individual fish length, weight, or condition factor between the treatments, likely because of large variances in body size due to sexual dimorphism and small sample sizes. The suspended array did not interfere with the hydraulic self-cleaning of the circular tanks. The results of this study support the use of vertically-suspended structures to improve the hatchery rearing performance of Atlantic salmon in circular tanks.展开更多
The effects of different feeds and feeding regimes on growth performance, flesh quality and fecal viscosity of Atlantic salmon （Salmo salar L.） in recirculating aquaculture systems （R.AS） were investigated. Fish ...The effects of different feeds and feeding regimes on growth performance, flesh quality and fecal viscosity of Atlantic salmon （Salmo salar L.） in recirculating aquaculture systems （R.AS） were investigated. Fish （initial body weight of 1677 g＋ 157 g） were fed with four commercial feeds （Nosan salmon-NS, Aller gold-AG, Skretting salmon-SS and Hart ye-HY） in two feeding regimes （80% and 100% satiation） for 78 d. The results showed that salmon specific growth ratio （SGR） and weight gain ratio （WGR） were significantly affected by feed type and feeding regime （P〈0.05）. Feed conversion ratio （FCR） varied between 0.93 and 3.40, which was significantly affected by feed type （P〈0.05）, and slightly improved with increased satiation degree. The activities of digestive enzymes including protease, lipase and amylase were also significantly affected by feed type and feeding regime （P〈0.05）, increasing with satiation degree. Flesh qualities for vitamin E, hydroxyproline （HYP）, liquid loss and muscle pH among all groups showed significant differences （P〈0.05）, ranging from 26.67 to 29.67, while no obvious difference was found in flesh color. Fecal viscosity for different treatments showed no significant difference, though improvement was found in 100% satiation group. From present experiment, it was concluded that both feed type and feeding regime can affect the important quality attributes of Atlantic salmon.展开更多
Electronic tags are widespread tools for studying aquatic animal behavior;however,tags risk behavioral manipulation and negative welfare outcomes.During an experiment to test behavioral differences of Atlantic salmon ...Electronic tags are widespread tools for studying aquatic animal behavior;however,tags risk behavioral manipulation and negative welfare outcomes.During an experiment to test behavioral differences of Atlantic salmon Sal mo salar in different aquaculture cage types,including ones expected to elicit deeper swimming behavior,we found negative tagging effects depending on whether cages were depth-modified.In the experiment,data storage tags implanted in Atlantic salmon tracked their depth behavior and survival in unmodified sea-cages and depth-modified seacages that forced fish below or into a narrow seawater-or freshwater-filled snorkel tube from a 4 m net roof to the surface.All tagged individuals survived in unmodified cages;however,survival was reduced to 62%in depth-modified cages.Survivors in depth-modified cages spent considerably less time above 4 m than those in unmodified cages,and dying individuals in depth-modified cages tended to position in progressively shallower water.The maximum depth that fish in our study could attain neutral buoyancy was estimated at 22 m in seawater.We calculated that the added tag weight in water reduced this to 8 m,and subtracting the tag volume from the peritoneal cavity where the swim bladder reinflates reduced this further to 4 m.We conclude that the internal tag weight and volume affected buoyancy regulation as well as the survival and behavior of tagged fish.Future tagging studies on aquatic animals should carefully consider the buoyancy-related consequences of internal tags with excess weight in water,and the inclusion of data from dying tagged animals when estimating normal depth behaviors.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)to u...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 16S rRNA genes in the samples were analyzed by MiSeq 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 fish included Proteobacteria(44.33%),Actinobacteria(17.89%),Baeteroidetes(15.25%),and Firmicutes(9.11%),among which the families Mierococcaceae and Oxalobacteraceae and genera Sphingomonas,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 offers 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
Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using...Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P<0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P>0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.展开更多
Salmo trutta is one of the major native economic fishes in Tibet. The biological characteristics, muscle nutrition composition, molecular biology, breeding and resources status of S： trutta are summarized.
Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rare...Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.展开更多
This 121-day experiment evaluated the rearing performance of brown trout Salmo trutta fed one of two isonitrogenous and isocaloric diets and reared at velocities of either 2.8 or 16.1 cm/s. Fishmeal was the primary pr...This 121-day experiment evaluated the rearing performance of brown trout Salmo trutta fed one of two isonitrogenous and isocaloric diets and reared at velocities of either 2.8 or 16.1 cm/s. Fishmeal was the primary protein source for the reference diet, and bioprocessed soybean meal replaced approximately 67% of the fishmeal in the experimental diet. At the end of the experiment, there were no significant differences in gain, percent gain, feed conversion rates, or specific growth rates between the dietary treatments. There were also no significant differences in intestinal morphology, splenosomatic, hepatosomatic, and viscerosomatic indices related to diet composition. However, gain, percent gain, feed fed, and specific growth rate were all significantly greater in brown trout reared at the higher velocity. No significant differences in any of the other variables measured were observed between the velocity treatments. There were no significant interactions between diet and velocity in any of the variables. Based on the results of this study, bioprocessed soybean meal can replace at least 67% of the fishmeal in brown trout diets, regardless of the rearing velocities used in this study. However, higher rearing velocities are recommended to maximize juvenile brown trout growth rates.展开更多
Atlantic salmon(Salmo salar)is an important economic fish that is seriously threatened by various viruses.A cell line designated as ASF derived from the caudal fin tissue of Atlantic salmon was established and charact...Atlantic salmon(Salmo salar)is an important economic fish that is seriously threatened by various viruses.A cell line designated as ASF derived from the caudal fin tissue of Atlantic salmon was established and characterized in this study.ASF cells grew well in Dulbecco’s modified Eagle’s medium(DMEM)containing 20%fetal bovine serum at 20℃.DNA sequencing and comparative analysis of the cytochrome B gene verified that the ASF cell line originated from Atlantic salmon.Chromosome analysis indicated that the modal chromosome number of ASF cells was 58.Viral susceptibility test showed that ASF cells were susceptive to two important fish viruses,viral hemorrhagic septicemia virus(VHSV)and red-spotted grouper nervous necrosis virus(RGNNV).Viral replication in ASF cells was further confirmed by qRT-PCR and transmission electron microscopy.Moreover,VHSV and RGNNV infections could induce the cellular responses in ASF cells,as indicated by the differential expression of cellular antiviral response-related genes,interferon-1 and Mx-1.In conclusion,the newly established ASF cell line can be applied as an in vitro tool in fish virology and immunity studies.展开更多
The combined effects of feeding rate(0.8%,1.0%,and 1.2%initial body weight/day),feeding frequency(two,three,and four times/day) and stocking density(10,15,and 20 kg/m3) in recirculating aquaculture systems(RAS) on gro...The combined effects of feeding rate(0.8%,1.0%,and 1.2%initial body weight/day),feeding frequency(two,three,and four times/day) and stocking density(10,15,and 20 kg/m3) in recirculating aquaculture systems(RAS) on growth performance,digestion and waste generation of Atlantic salmon(Salmo salar L.) were investigated in an 8-week orthogonal experiment(L9(3)3) with a constant daily water renewal at 7.50%of total volume.No mortality occurred during the experimental period.Feed conversion ratio(FCR) varied from 0.90 to 1.13 and specific growth rate(SGR) ranged from 0.48%to 0.69%/day.SGR,thermal growth coefficient(TGC) and FCR were not significantly(P>0.05) affected by the three factors,while net protein utilization(NPU) was significantly(P<0.05) affected.Apparent digestibility coefficients(ADC) of dry matter in the present study were in the range 66.12%-73.55%.ADC in protein,lipid and energy were statistically different among all treatments and in the range of 90.07%-93.67%,81.54%-89.15%,and67.55%-71.87%,respectively.The proportion of mean total ammonia nitrogen excreted ranged from 1.37%to 1.64%of feed nitrogen at steady state,and the concentration of nitrogenous and phosphorus compounds were differently correlated to the three factors.The results will provide valuable reference data for culture management decisions in the Atlantic salmon farming industry.展开更多
Mariculture has been one of the fastest-growing global food production sectors over the past three decades.With the congestion of space and deterioration of the environment in coastal regions,offshore aquaculture has ...Mariculture has been one of the fastest-growing global food production sectors over the past three decades.With the congestion of space and deterioration of the environment in coastal regions,offshore aquaculture has gained increasing attention.Atlantic salmon(Salmo salar)and rainbow trout(Oncorhynchus mykiss)are two important aquaculture species and contribute to 6.1%of world aquaculture production of finfish.In the present study,we established species distribution models(SDMs)to identify the potential areas for offshore aquaculture of these two cold-water fish species considering the mesoscale spatio-temporal thermal heterogeneity of the Yellow Sea.The values of the area under the curve(AUC)and the true skill statistic(TSS)showed good model performance.The suitability index(SI),which was used in this study to quantitatively assess potential offshore aquaculture sites,was highly dynamic at the surface water layer.However,high SI values occurred throughout the year at deeper water layers.The potential aquaculture areas for S.salar and O.mykiss in the Yellow Sea were estimated as 52,270±3275(95%confidence interval,CI)and 146,831±15,023 km^(2),respectively.Our results highlighted the use of SDMs in identifying potential aquaculture areas based on environmental variables.Considering the thermal heterogeneity of the environment,this study suggested that offshore aquaculture for Atlantic salmon and rainbow trout was feasible in the Yellow Sea by adopting new technologies(e.g.,sinking cages into deep water)to avoid damage from high temperatures in summer.展开更多
文摘Environmental enrichment is the incorporation of materials into hatchery tanks to simulate a more natural rearing environment. This study investigated the use of a vertically-suspended plastic conduit array as enrichment in 3.63 m circular tanks during Atlantic salmon (Salmo salar) rearing. After 168 days, feed conversion ratio was significantly improved for salmon reared in tanks with enrichment compared to the barren control tanks. Final tank weights and weight gain were not significantly different, although the difference in mean gain of 182.0 kg in the enriched tanks compared to 162.9 kg in the control tanks approached significance. There were no significant differences in individual fish length, weight, or condition factor between the treatments, likely because of large variances in body size due to sexual dimorphism and small sample sizes. The suspended array did not interfere with the hydraulic self-cleaning of the circular tanks. The results of this study support the use of vertically-suspended structures to improve the hatchery rearing performance of Atlantic salmon in circular tanks.
基金supported by the National Key Technologies R&D Program(2011BAD13B04)the earmarked fund for Modern Agro-industry Technology Research System(CARS-48)the National Natural Science Foundation of China(No.31240012)
文摘The effects of different feeds and feeding regimes on growth performance, flesh quality and fecal viscosity of Atlantic salmon （Salmo salar L.） in recirculating aquaculture systems （R.AS） were investigated. Fish （initial body weight of 1677 g＋ 157 g） were fed with four commercial feeds （Nosan salmon-NS, Aller gold-AG, Skretting salmon-SS and Hart ye-HY） in two feeding regimes （80% and 100% satiation） for 78 d. The results showed that salmon specific growth ratio （SGR） and weight gain ratio （WGR） were significantly affected by feed type and feeding regime （P〈0.05）. Feed conversion ratio （FCR） varied between 0.93 and 3.40, which was significantly affected by feed type （P〈0.05）, and slightly improved with increased satiation degree. The activities of digestive enzymes including protease, lipase and amylase were also significantly affected by feed type and feeding regime （P〈0.05）, increasing with satiation degree. Flesh qualities for vitamin E, hydroxyproline （HYP）, liquid loss and muscle pH among all groups showed significant differences （P〈0.05）, ranging from 26.67 to 29.67, while no obvious difference was found in flesh color. Fecal viscosity for different treatments showed no significant difference, though improvement was found in 100% satiation group. From present experiment, it was concluded that both feed type and feeding regime can affect the important quality attributes of Atlantic salmon.
文摘Electronic tags are widespread tools for studying aquatic animal behavior;however,tags risk behavioral manipulation and negative welfare outcomes.During an experiment to test behavioral differences of Atlantic salmon Sal mo salar in different aquaculture cage types,including ones expected to elicit deeper swimming behavior,we found negative tagging effects depending on whether cages were depth-modified.In the experiment,data storage tags implanted in Atlantic salmon tracked their depth behavior and survival in unmodified sea-cages and depth-modified seacages that forced fish below or into a narrow seawater-or freshwater-filled snorkel tube from a 4 m net roof to the surface.All tagged individuals survived in unmodified cages;however,survival was reduced to 62%in depth-modified cages.Survivors in depth-modified cages spent considerably less time above 4 m than those in unmodified cages,and dying individuals in depth-modified cages tended to position in progressively shallower water.The maximum depth that fish in our study could attain neutral buoyancy was estimated at 22 m in seawater.We calculated that the added tag weight in water reduced this to 8 m,and subtracting the tag volume from the peritoneal cavity where the swim bladder reinflates reduced this further to 4 m.We conclude that the internal tag weight and volume affected buoyancy regulation as well as the survival and behavior of tagged fish.Future tagging studies on aquatic animals should carefully consider the buoyancy-related consequences of internal tags with excess weight in water,and the inclusion of data from dying tagged animals when estimating normal depth behaviors.
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 16S rRNA genes in the samples were analyzed by MiSeq 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 fish included Proteobacteria(44.33%),Actinobacteria(17.89%),Baeteroidetes(15.25%),and Firmicutes(9.11%),among which the families Mierococcaceae and Oxalobacteraceae and genera Sphingomonas,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 offers 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 Key Technologies R&D Program of China(No.2011BAD13B04)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-EW-Q212)+2 种基金the Public Service Sectors(Agriculture)Special Project(No.201003024)the Earmarked Fund for Modern Agro-Industry Technology Research Systemthe Shandong Program for Development of Science and Technology(No.2013GHY11514)
文摘Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P<0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P>0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.
基金Supported by Natural Science Foundation of the Tibet Autonomous Region"Compensation Growth and Compensation Mechanism of Salmo trutta Larvae after Starvation"(2016ZR-NK-15)
文摘Salmo trutta is one of the major native economic fishes in Tibet. The biological characteristics, muscle nutrition composition, molecular biology, breeding and resources status of S： trutta are summarized.
基金Supported by the Qingdao Postdoctoral Application Research Project(No.Y6KY01110N)the National Natural Science Foundation of China(Nos.31472312,41306152,31402283)+2 种基金the Qingdao Innovation Talents Program(No.13-CX-16)the National Key Technologies R&D Program of China(No.2014BAD08B09)the Earmarked Fund for Modem AgroIndustry Technology Research System(No.CARS-48)
文摘Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.
文摘This 121-day experiment evaluated the rearing performance of brown trout Salmo trutta fed one of two isonitrogenous and isocaloric diets and reared at velocities of either 2.8 or 16.1 cm/s. Fishmeal was the primary protein source for the reference diet, and bioprocessed soybean meal replaced approximately 67% of the fishmeal in the experimental diet. At the end of the experiment, there were no significant differences in gain, percent gain, feed conversion rates, or specific growth rates between the dietary treatments. There were also no significant differences in intestinal morphology, splenosomatic, hepatosomatic, and viscerosomatic indices related to diet composition. However, gain, percent gain, feed fed, and specific growth rate were all significantly greater in brown trout reared at the higher velocity. No significant differences in any of the other variables measured were observed between the velocity treatments. There were no significant interactions between diet and velocity in any of the variables. Based on the results of this study, bioprocessed soybean meal can replace at least 67% of the fishmeal in brown trout diets, regardless of the rearing velocities used in this study. However, higher rearing velocities are recommended to maximize juvenile brown trout growth rates.
基金supported by the China Postdoctoral Science Foundation (No. 2019M653152)the Pearl River S&T Nova Program of Guangzhou (No. 201806010047)+2 种基金the National Natural Science Foundation of China (No. 31771587)Fundamental Research Funds for the Central Universities (No. 19lgpy102)the Natural Science Foundation of Guangdong Province (No. 2019A1515110842)
文摘Atlantic salmon(Salmo salar)is an important economic fish that is seriously threatened by various viruses.A cell line designated as ASF derived from the caudal fin tissue of Atlantic salmon was established and characterized in this study.ASF cells grew well in Dulbecco’s modified Eagle’s medium(DMEM)containing 20%fetal bovine serum at 20℃.DNA sequencing and comparative analysis of the cytochrome B gene verified that the ASF cell line originated from Atlantic salmon.Chromosome analysis indicated that the modal chromosome number of ASF cells was 58.Viral susceptibility test showed that ASF cells were susceptive to two important fish viruses,viral hemorrhagic septicemia virus(VHSV)and red-spotted grouper nervous necrosis virus(RGNNV).Viral replication in ASF cells was further confirmed by qRT-PCR and transmission electron microscopy.Moreover,VHSV and RGNNV infections could induce the cellular responses in ASF cells,as indicated by the differential expression of cellular antiviral response-related genes,interferon-1 and Mx-1.In conclusion,the newly established ASF cell line can be applied as an in vitro tool in fish virology and immunity studies.
基金Supported by the Modern Agro-Industry Technology Research System(No.CARS-48)the National Natural Science Foundation of China(No.31240012)+1 种基金the Special Foundation for Postdoctoral Innovative Projects of Shandong Province(No.201101009)the National Key Technology R&D Program of China(No.2011BAD13B04)
文摘The combined effects of feeding rate(0.8%,1.0%,and 1.2%initial body weight/day),feeding frequency(two,three,and four times/day) and stocking density(10,15,and 20 kg/m3) in recirculating aquaculture systems(RAS) on growth performance,digestion and waste generation of Atlantic salmon(Salmo salar L.) were investigated in an 8-week orthogonal experiment(L9(3)3) with a constant daily water renewal at 7.50%of total volume.No mortality occurred during the experimental period.Feed conversion ratio(FCR) varied from 0.90 to 1.13 and specific growth rate(SGR) ranged from 0.48%to 0.69%/day.SGR,thermal growth coefficient(TGC) and FCR were not significantly(P>0.05) affected by the three factors,while net protein utilization(NPU) was significantly(P<0.05) affected.Apparent digestibility coefficients(ADC) of dry matter in the present study were in the range 66.12%-73.55%.ADC in protein,lipid and energy were statistically different among all treatments and in the range of 90.07%-93.67%,81.54%-89.15%,and67.55%-71.87%,respectively.The proportion of mean total ammonia nitrogen excreted ranged from 1.37%to 1.64%of feed nitrogen at steady state,and the concentration of nitrogenous and phosphorus compounds were differently correlated to the three factors.The results will provide valuable reference data for culture management decisions in the Atlantic salmon farming industry.
基金supported by the National Natural Science Foundation of China(U1906206 and 42025604)the National Key Research and Development Program of China(Project 2019YFD0901002)the Fundamental Research Funds for the Central Universities.
文摘Mariculture has been one of the fastest-growing global food production sectors over the past three decades.With the congestion of space and deterioration of the environment in coastal regions,offshore aquaculture has gained increasing attention.Atlantic salmon(Salmo salar)and rainbow trout(Oncorhynchus mykiss)are two important aquaculture species and contribute to 6.1%of world aquaculture production of finfish.In the present study,we established species distribution models(SDMs)to identify the potential areas for offshore aquaculture of these two cold-water fish species considering the mesoscale spatio-temporal thermal heterogeneity of the Yellow Sea.The values of the area under the curve(AUC)and the true skill statistic(TSS)showed good model performance.The suitability index(SI),which was used in this study to quantitatively assess potential offshore aquaculture sites,was highly dynamic at the surface water layer.However,high SI values occurred throughout the year at deeper water layers.The potential aquaculture areas for S.salar and O.mykiss in the Yellow Sea were estimated as 52,270±3275(95%confidence interval,CI)and 146,831±15,023 km^(2),respectively.Our results highlighted the use of SDMs in identifying potential aquaculture areas based on environmental variables.Considering the thermal heterogeneity of the environment,this study suggested that offshore aquaculture for Atlantic salmon and rainbow trout was feasible in the Yellow Sea by adopting new technologies(e.g.,sinking cages into deep water)to avoid damage from high temperatures in summer.
