Viral diseases represent one of the major threats for salmonids aquaculture.Early detection and identification of viral pathogens is the main prerequisite prior to undertaking effective prevention and control measures...Viral diseases represent one of the major threats for salmonids aquaculture.Early detection and identification of viral pathogens is the main prerequisite prior to undertaking effective prevention and control measures.Rapid,sensitive,efficient and portable detection method is highly essential for fish viral diseases detection.Biosensor strategies are highly prevalent and fulfill the expanding demands of on-site detection with fast response,cost-effectiveness,high sensitivity,and selectivity.With the development of material science,the nucleic acid biosensors fabricated by semiconductor have shown great potential in rapid and early detection or screening for diseases at salmonids fisheries.This paper reviews the current detection development of salmonids viral diseases.The present limitations and challenges of salmonids virus diseases surveillance and early detection are presented.Novel nucleic acid semiconductor biosensors are briefly reviewed.The perspective and potential application of biosensors in the on-site detection of salmonids diseases are discussed.展开更多
There is an increasing demand for salmonid authentication due to the globalization of the salmonid trade.DNA barcoding and mini-DNA barcoding are widely used for identifying fish species based on a fragment of the mit...There is an increasing demand for salmonid authentication due to the globalization of the salmonid trade.DNA barcoding and mini-DNA barcoding are widely used for identifying fish species based on a fragment of the mitochondrial cytochrome c oxidase subunit I(COI)sequence.In this study,rainbow trout(Oncorhynchus mykiss),steelhead trout(O.mykiss),and Atlantic salmon(Salmo salar)collected from two salmonid aquaculture bases in China were authenticated by DNA barcoding(about 650 bp)and mini-DNA barcoding(127 bp)to evaluate the accuracy of the two methods in the identification of different salmonid species.The results revealed that both methods could effectively distinguish O.mykiss and S.salar with 100%accuracy.However,the two methods failed to separate rainbow trout(O.mykiss)and steelhead trout(O.mykiss),which are the same species but cultured in different water environments.Moreover,salmonid samples from three main distribution channels in the Qingdao area(traditional supermarkets,online supermarkets,and sushi bars)were identified by the two methods.Substitution of S.salar with O.mykiss was discovered,and the 27.78%overall substitution rate of salmonids in the Qingdao area was higher than those in other regions reported in previous studies.In addition,the mislabeling rates of salmonids from traditional supermarkets,online supermarkets,and sushi bars were compared in this study.The mislabeling rate was significantly greater in sushi bars(50%)than in the other two channels(16.67%),suggesting that stronger monitoring and enforcement measures are necessary for the aquatic food catering industry.展开更多
Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied spec...Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied species.Here we describe the morphological variability of two size groups of Siberian taimen juveniles from the eastern(Amur River basin)and western(Kama River basin)parts of the species distribution.The largest morphological differentiation of Siberian taimen juveniles was observed at the inter-basin level.In the Amur River basin,Siberian taimen juveniles also differed morphologically even at sites located at a distance of 20 km from each other,which may be explained by a small home-range inhabitation of juveniles leading to the formation of their morphotype determined by local environmental conditions.The pattern of allometry varies in taimen from different rivers,which could be related to the ontogenetic shift of ecological niches and the level of heterogeneity of the river environment.展开更多
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
This study examined the effects of five different colors of vertically-suspended environmental enrichment on the growth of juvenile Shasta strain rainbow trout (<i>Oncorhynchus mykiss</i>) during hatchery ...This study examined the effects of five different colors of vertically-suspended environmental enrichment on the growth of juvenile Shasta strain rainbow trout (<i>Oncorhynchus mykiss</i>) during hatchery rearing in circular tanks. The colors used were silver (unpainted aluminum—control), safety red, semi-gloss black, hunter green, and safety blue. After 86 days, total tank weight, weight gain, and feed conversion ration were not significantly different among any of the color treatments. Individual fish weights, lengths, and condition factors were also not significantly different among the treatments. The results of this study indicate that the relatively small amount of color present on the suspended structure did not affect rainbow trout growth. Thus, the inherent silver color of the aluminum angles does not need to be changed.展开更多
A combination of two forms of environmental enrichment (in-tank structure and exercise) was evaluated during the hatchery rearing of juvenile rainbow trout Oncorhynchus mykiss. The study used four treatments: 1) neith...A combination of two forms of environmental enrichment (in-tank structure and exercise) was evaluated during the hatchery rearing of juvenile rainbow trout Oncorhynchus mykiss. The study used four treatments: 1) neither exercise nor structure, 2) exercise without structure, 3) structure without exercise, and 4) both exercise and structure. Velocities in the unexercised tanks were a constant 12.2 cm-s-1. Velocities in the exercised tanks alternated weekly with one week at 12.2 cm-s-1 followed by a week at 30.5 cm-s-1. Structural enrichment consisted of an array of vertically-suspended aluminum angles. The use of either environmental enrichment technique significantly improved final tank weight, gain, percent gain, and specific growth rate. Feed conversion ratio was significantly and positively influenced only by structure, but fish on the exercise routine were overfed. There were no significant interactions between exercise and structure, indicating that each form of environmental enrichment operates independently. The results of this study indicate fish rearing performance can be improved with the addition of either vertically-suspended aluminum angles or an exercise routine, but the combination of the two techniques may not be needed to improve rainbow trout growth.展开更多
Freshwater salmonids gain increasing popularity as diet fish and are an important dietary source of omega-3 polyunsaturated fatty acids (PUFA) for humans. The aim of this study was to investigate effects of alternativ...Freshwater salmonids gain increasing popularity as diet fish and are an important dietary source of omega-3 polyunsaturated fatty acids (PUFA) for humans. The aim of this study was to investigate effects of alternative feeds from domestic sources on fish growth and lipid composition of the sparctic Alsatian charr (Salvelinus alpinus X fontinalis), commonly used in freshwater aquaculture in Europe. In this fish feeding experiment, we used a control feed (32% fish meal;feed F1) and experimental diets containing generally only half the amount of fish meal, which was replaced in equal parts by poultry (F2), two different pork by-product meals (F3 and F4), plant-based feeds (F5), or by a feed containing 25% fish and 15% poultry meal (F6) that had a similar caloric value compared to the other feeds. Six hundred charrs of similar initial weight (ca. 90 g) were randomly distributed into 12 tanks (50/tank) of 1.4 m3, supplied with subalpine spring water, and fed one of the feeds. Fish biomass development was the highest in fish fed diet F6, followed by F1, F2, and F5. Pork by-product meals as partial replacement of fish meal resulted on average in a 25% lower biomass gain compared to charr feeding on poultry by-product meal (F6). The use of poultry or pork by-product meals as partial fish meal replacements did not significantly change the total lipids or fatty acids retained in these fish. This study shows that these alternative feeds, with similar lipid sources, had no significant effect on the fatty acid composition in Alsatian charr, however, poultry by-product meal as partial replacement of marine fish meal clearly enhanced charr biomass by 15% relative to conventional fish meals.展开更多
Two hundred and forty-three juvenile rainbow trout <span style="font-size:12px;font-family:Verdana;">Oncorhynchus mykiss<span style="font-size:12px;font-family:Verdana;"> ranging from 7...Two hundred and forty-three juvenile rainbow trout <span style="font-size:12px;font-family:Verdana;">Oncorhynchus mykiss<span style="font-size:12px;font-family:Verdana;"> ranging from 73 to 119 mm <span style="font-size:12px;font-family:Verdana;">were <span style="font-size:12px;font-family:Verdana;">implanted with 8, 9, or 10 mm Passive Integrated Transponder (PIT) tags, with tag retention and fish survival observed for 343 days. Similarly, 173 brown trout <span style="font-size:12px;font-family:Verdana;">Salmo trutta<span style="font-size:12px;font-family:Verdana;"> ranging from 71 to 86 mm were implanted with 8 or 10 mm PIT tags and observed for 293 days. Over the entire duration of the study, rainbow trout ejected only six tags, while no tags were ejected from the brown trout. All of the rainbow trout tag ejections occurred before 50 days post-tagging. There was no significant difference in the length or weight of fish that ejected tags compared to those that retained tags. No fish died during the trials. These results indicate that rainbow trout and brown trout at the sizes used in this study can be safely implanted with, and subsequently retain, up to 10 mm PIT tags for durations of nearly one year.展开更多
An effect of hydropower and hydropeaking regulation in rivers is stranding of fish. Those fishes that survive stranding may experience stranding as a stressful situation. In four experimental stranding experiments (ea...An effect of hydropower and hydropeaking regulation in rivers is stranding of fish. Those fishes that survive stranding may experience stranding as a stressful situation. In four experimental stranding experiments (each with 6 individuals in 10 control and 10 treatment replicates), the energetic consequences of two forms of stranding (i.e. trapping and beaching) of juvenile Atlantic salmon (Salmo salar) were investigated in summer and winter. Restricted food access in the experimental channels ensured that effects of hydropeaking could be revealed. Mean fish length ranged between 60 mm and 110 mm among experiments. Both during the winter and summer experiments fish did not grow in length, neither in the control nor in the treatment channels and fish lost body mass as well as body fat in all experiments (body fat in summer trapping experiment not determined). The four experiments revealed similar results: stranding did not affect growth or energy content. Despite the severity of the stranding and the resulting mortality, which was especially high during summer, no stranding related effects on fish performance could be detected.展开更多
Experimental infection of fish for vaccine efficacy studies is associated with several limitations. Administration of live bacteria with the purpose of causing disease in fish can be performed by co-habitation, immers...Experimental infection of fish for vaccine efficacy studies is associated with several limitations. Administration of live bacteria with the purpose of causing disease in fish can be performed by co-habitation, immersion or injection. We have developed a new Aeromonas salmonicida challenge method for rainbow trout and have applied it for evaluation of furunculosis vaccine efficacy. The method reveals development of systemic immunity in fish as live bacteria are introduced in the tail fin epidermis distant from the vaccine injection site (peritoneal cavity). This method seeks to mimic natural infection in fish farms where tail biting and therefore bacterial exposure to tail fin ulcers is widespread. By use of a multi-needle device ten epidermal perforations were introduced in the dorsal part of the tail fin of anaesthetized rainbow trout (vaccinated or naive). Subsequently 100 μL (3.4 × 10<sup>8</sup> colony-forming units (CFU) mL<sup>-1</sup>) of a 48 hour culture of Aeromonas salmonicida subsp. salmonicida strain 090710-1/23 was placed at the perforation site for 60 sec whereafter fish were allowed to regain consciousness in clean freshwater. Immunohistochemistry and scanning electron microscopy illustrated the spread of bacteria from the injection site. Classical furunculosis symptoms associated with a high morbidity rate were observed in control fish whereas vaccinated fish exhibited a significantly higher survival.展开更多
This study evaluated the effects of two water velocities and three types of vertically-suspended environmental enrichment during the rearing of juvenile rainbow trout (Oncorhynchus mykiss;mean ± SE, initial weigh...This study evaluated the effects of two water velocities and three types of vertically-suspended environmental enrichment during the rearing of juvenile rainbow trout (Oncorhynchus mykiss;mean ± SE, initial weight 4 ± 1 g and total length 71 ± 2 mm) in 1.8m diameter circular tanks. The 2 × 3 experimental design used two velocities (12.2 cm·s-1 and 30.5 cm·s-1) and three structural treatments (aluminum rod array, plastic spheres, or no structure). After 116 days, the fish reared without any structure (control) at 30.5 cm·s-1 had significantly lower total tank weight, gain, percent gain, feed conversion ratio, and specific growth rate compared to the other treatments. Similarly, the fish reared with a velocity of 30.5 cm·s-1 without structure were significantly shorter and lighter than those in the other treatments. There was no significant difference in condition factor and relative fin lengths among the treatments. These results indicate that vertically-suspended environmental enrichment may be impacting fish rearing performance by altering tank water velocities.展开更多
Invasive hybridization and introgression pose a serious threat to the persistence of many native species. Understand- ing the effects of hybridization on native populations （e.g., fitness consequences） requires nume...Invasive hybridization and introgression pose a serious threat to the persistence of many native species. Understand- ing the effects of hybridization on native populations （e.g., fitness consequences） requires numerous species-diagnostic loci dis- tributed genome-wide. Here we used RAD sequencing to discover thousands of single-nucleotide polymorphisms （SNPs） that are diagnostic between rainbow trout （RBT, Oncorhynchus mykiss）, the world＇s most widely introduced fish, and native westslope cutthroat trout （WCT, （9. clarkii lewisi） in the northern Rocky Mountains, USA. We advanced previous work that identified 4,914 species-diagnostic loci by using longer sequence reads （100 bp vs. 60 bp） and a larger set of individuals （n = 84）. We sequenced RAD libraries for individuals from diverse sampling sources, including native populations of WCT and hatchery broodstocks of WCT and RBT. We also took advantage of a newly released reference genome assembly for RBT to align our RAD loci. In total, we discovered 16,788 putatively diagnostic SNPs, 10,267 of which we mapped to anchored chromosome locations on the RBT genome. A small portion of previously discovered putative diagnostic loci （325 of 4,914） were no longer diagnostic （i.e., fixed between species） based on our wider survey of non-hybridized RBT and WCT individuals. Our study suggests that RAD loci mapped to a draft genome assembly could provide the marker density required to identify genes and chromosomal regions in- fluencing selection in admixed populations of conservation concern and evolutionary interest [Current Zoology 61 （1）： 146-154, 2015].展开更多
This experiment evaluated the use of an exercise routine and vertically-sus<span style="font-family:Verdana;">-<span style="font-family:;" "=""><span style="font-...This experiment evaluated the use of an exercise routine and vertically-sus<span style="font-family:Verdana;">-<span style="font-family:;" "=""><span style="font-family:Verdana;">pended structure during juvenile landlocked fall Chinook salmon (<span style="font-family:Verdana;">Oncor<span style="font-family:Verdana;">hynchus tshawytscha<span style="font-family:Verdana;">;<span style="font-family:;" "=""> <span style="font-family:Verdana;">mean ± SE, initial weight 1.47 ± 0.03 g, total length 56.4 ± 0.4 mm) rearing. Four treatments were used: 1<span style="font-family:Verdana;">)<span style="font-family:Verdana;"> no exercise routine nor vertically-suspended structure, 2<span style="font-family:Verdana;">)<span style="font-family:Verdana;"> exercise and structure, 3<span style="font-family:Verdana;">)<span style="font-family:Verdana;"> exercise and no structure, and 4<span style="font-family:Verdana;">)<span style="font-family:;" "=""><span style="font-family:Verdana;"> no exercise and structure. <span style="font-family:Verdana;">Water velocities in tanks without exercise were 12 cm/s, where-as the exercise routine consisted of seven days at 12 cm/s followed by seven days at 18 cm/s. The structure was an array consisting of four vertically-suspended aluminum angles. Total tank gain and percent gain were significantly greater after 50 days in the tanks of salmon subjected to the exercise routine and structure compared to the three other treatments. <span style="font-family:Verdana;">Gain and percent gain were also significantly greater in the tanks receiving<span style="font-family:Verdana;"> structure without exercise compared to tanks with exercise and no structure or tanks with neither exercise nor structure. Feed conversion ratio was signif<span style="font-family:Verdana;">icantly improved in the salmon tanks with structure and without exercise<span style="font-family:Verdana;"> com<span style="font-family:;" "=""><span style="font-family:Verdana;">pared to all other treatments. There were no significant differences for indi<span style="font-family:Verdana;">vidual fish weight, total length, specific growth rate, or condition factor<span style="font-family:Verdana;"> among any of the treatments at the end of the experiment. <span style="font-family:Verdana;">These results indicate that the use of both an exercise routine and vertically-suspended structure may be beneficial during the rearing of juvenile landlocked fall Chinook salmon.展开更多
Eyed salmonid eggs can be subjected to large temperature swings during development, particularly when shipped in ice-filled containers from broodstock facilities to production hatcheries. This study examined the effec...Eyed salmonid eggs can be subjected to large temperature swings during development, particularly when shipped in ice-filled containers from broodstock facilities to production hatcheries. This study examined the effect of thermal tempering on the survival of brown trout <em>Salmo trutta</em> and rainbow trout <em>Oncorhynchus mykiss</em> eyed eggs to hatch. Eyed eggs at 1<span style="white-space:nowrap;">°</span>C were either directly placed in 11<span style="white-space:nowrap;">°</span>C water or allowed to thermally temper from 1<span style="white-space:nowrap;">°</span>C to 11<span style="white-space:nowrap;">°</span>C gradually over an hour. In addition, each of the tempering treatments occurred either with or without a 10-minute iodophor disinfection treatment. Tempering had no significant effect on survival-to-hatch in either species (85% - 97%). However, survival was significantly lower in rainbow trout eggs subjected to iodine disinfection (73% - 75%) compared to non-disinfected eggs (91% - 97%), likely because of the close proximity to hatch. The results of this study indicate that slowly raising the temperature (thermal tempering) of brown trout and rainbow trout eyed eggs is unnecessary. Additionally, iodine disinfection of eyed salmonid eggs in close proximity to hatching should be avoided.展开更多
The review presents data on structural changes,physiological and biochemical reactions occurring at salmon young fishes during smoltification.It is shown,that young salmon fishes located in fresh water,in the process ...The review presents data on structural changes,physiological and biochemical reactions occurring at salmon young fishes during smoltification.It is shown,that young salmon fishes located in fresh water,in the process of smoltification undergo a complex of structural,physiological and biochemical changes directed on preparation of the organism for living in the sea.These changes cause stress reaction which excites young fishes to migrate down the river towards the sea.Measures to improve reproduction of young salmon fishes at fish farms are offered.展开更多
基金supported by the National Key Research and Development Program of China(2022YFC2601304)National Key Research and Development Program of China(2022YFC2602100)。
文摘Viral diseases represent one of the major threats for salmonids aquaculture.Early detection and identification of viral pathogens is the main prerequisite prior to undertaking effective prevention and control measures.Rapid,sensitive,efficient and portable detection method is highly essential for fish viral diseases detection.Biosensor strategies are highly prevalent and fulfill the expanding demands of on-site detection with fast response,cost-effectiveness,high sensitivity,and selectivity.With the development of material science,the nucleic acid biosensors fabricated by semiconductor have shown great potential in rapid and early detection or screening for diseases at salmonids fisheries.This paper reviews the current detection development of salmonids viral diseases.The present limitations and challenges of salmonids virus diseases surveillance and early detection are presented.Novel nucleic acid semiconductor biosensors are briefly reviewed.The perspective and potential application of biosensors in the on-site detection of salmonids diseases are discussed.
基金the National Key Research and Development Program of China(No.2019YFD0901000)the Natural Science Foundation of Shandong Pro-vince,China(No.ZR2020MC194).
文摘There is an increasing demand for salmonid authentication due to the globalization of the salmonid trade.DNA barcoding and mini-DNA barcoding are widely used for identifying fish species based on a fragment of the mitochondrial cytochrome c oxidase subunit I(COI)sequence.In this study,rainbow trout(Oncorhynchus mykiss),steelhead trout(O.mykiss),and Atlantic salmon(Salmo salar)collected from two salmonid aquaculture bases in China were authenticated by DNA barcoding(about 650 bp)and mini-DNA barcoding(127 bp)to evaluate the accuracy of the two methods in the identification of different salmonid species.The results revealed that both methods could effectively distinguish O.mykiss and S.salar with 100%accuracy.However,the two methods failed to separate rainbow trout(O.mykiss)and steelhead trout(O.mykiss),which are the same species but cultured in different water environments.Moreover,salmonid samples from three main distribution channels in the Qingdao area(traditional supermarkets,online supermarkets,and sushi bars)were identified by the two methods.Substitution of S.salar with O.mykiss was discovered,and the 27.78%overall substitution rate of salmonids in the Qingdao area was higher than those in other regions reported in previous studies.In addition,the mislabeling rates of salmonids from traditional supermarkets,online supermarkets,and sushi bars were compared in this study.The mislabeling rate was significantly greater in sushi bars(50%)than in the other two channels(16.67%),suggesting that stronger monitoring and enforcement measures are necessary for the aquatic food catering industry.
文摘Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied species.Here we describe the morphological variability of two size groups of Siberian taimen juveniles from the eastern(Amur River basin)and western(Kama River basin)parts of the species distribution.The largest morphological differentiation of Siberian taimen juveniles was observed at the inter-basin level.In the Amur River basin,Siberian taimen juveniles also differed morphologically even at sites located at a distance of 20 km from each other,which may be explained by a small home-range inhabitation of juveniles leading to the formation of their morphotype determined by local environmental conditions.The pattern of allometry varies in taimen from different rivers,which could be related to the ontogenetic shift of ecological niches and the level of heterogeneity of the river environment.
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.
文摘This study examined the effects of five different colors of vertically-suspended environmental enrichment on the growth of juvenile Shasta strain rainbow trout (<i>Oncorhynchus mykiss</i>) during hatchery rearing in circular tanks. The colors used were silver (unpainted aluminum—control), safety red, semi-gloss black, hunter green, and safety blue. After 86 days, total tank weight, weight gain, and feed conversion ration were not significantly different among any of the color treatments. Individual fish weights, lengths, and condition factors were also not significantly different among the treatments. The results of this study indicate that the relatively small amount of color present on the suspended structure did not affect rainbow trout growth. Thus, the inherent silver color of the aluminum angles does not need to be changed.
文摘A combination of two forms of environmental enrichment (in-tank structure and exercise) was evaluated during the hatchery rearing of juvenile rainbow trout Oncorhynchus mykiss. The study used four treatments: 1) neither exercise nor structure, 2) exercise without structure, 3) structure without exercise, and 4) both exercise and structure. Velocities in the unexercised tanks were a constant 12.2 cm-s-1. Velocities in the exercised tanks alternated weekly with one week at 12.2 cm-s-1 followed by a week at 30.5 cm-s-1. Structural enrichment consisted of an array of vertically-suspended aluminum angles. The use of either environmental enrichment technique significantly improved final tank weight, gain, percent gain, and specific growth rate. Feed conversion ratio was significantly and positively influenced only by structure, but fish on the exercise routine were overfed. There were no significant interactions between exercise and structure, indicating that each form of environmental enrichment operates independently. The results of this study indicate fish rearing performance can be improved with the addition of either vertically-suspended aluminum angles or an exercise routine, but the combination of the two techniques may not be needed to improve rainbow trout growth.
文摘Freshwater salmonids gain increasing popularity as diet fish and are an important dietary source of omega-3 polyunsaturated fatty acids (PUFA) for humans. The aim of this study was to investigate effects of alternative feeds from domestic sources on fish growth and lipid composition of the sparctic Alsatian charr (Salvelinus alpinus X fontinalis), commonly used in freshwater aquaculture in Europe. In this fish feeding experiment, we used a control feed (32% fish meal;feed F1) and experimental diets containing generally only half the amount of fish meal, which was replaced in equal parts by poultry (F2), two different pork by-product meals (F3 and F4), plant-based feeds (F5), or by a feed containing 25% fish and 15% poultry meal (F6) that had a similar caloric value compared to the other feeds. Six hundred charrs of similar initial weight (ca. 90 g) were randomly distributed into 12 tanks (50/tank) of 1.4 m3, supplied with subalpine spring water, and fed one of the feeds. Fish biomass development was the highest in fish fed diet F6, followed by F1, F2, and F5. Pork by-product meals as partial replacement of fish meal resulted on average in a 25% lower biomass gain compared to charr feeding on poultry by-product meal (F6). The use of poultry or pork by-product meals as partial fish meal replacements did not significantly change the total lipids or fatty acids retained in these fish. This study shows that these alternative feeds, with similar lipid sources, had no significant effect on the fatty acid composition in Alsatian charr, however, poultry by-product meal as partial replacement of marine fish meal clearly enhanced charr biomass by 15% relative to conventional fish meals.
文摘Two hundred and forty-three juvenile rainbow trout <span style="font-size:12px;font-family:Verdana;">Oncorhynchus mykiss<span style="font-size:12px;font-family:Verdana;"> ranging from 73 to 119 mm <span style="font-size:12px;font-family:Verdana;">were <span style="font-size:12px;font-family:Verdana;">implanted with 8, 9, or 10 mm Passive Integrated Transponder (PIT) tags, with tag retention and fish survival observed for 343 days. Similarly, 173 brown trout <span style="font-size:12px;font-family:Verdana;">Salmo trutta<span style="font-size:12px;font-family:Verdana;"> ranging from 71 to 86 mm were implanted with 8 or 10 mm PIT tags and observed for 293 days. Over the entire duration of the study, rainbow trout ejected only six tags, while no tags were ejected from the brown trout. All of the rainbow trout tag ejections occurred before 50 days post-tagging. There was no significant difference in the length or weight of fish that ejected tags compared to those that retained tags. No fish died during the trials. These results indicate that rainbow trout and brown trout at the sizes used in this study can be safely implanted with, and subsequently retain, up to 10 mm PIT tags for durations of nearly one year.
基金part of the EnviPEAK-project and has been financed by Centre for Environmental Design of Renewable Energy(CEDREN),one of the Norwegian Research Council’s Research Centres for Environmental Friendly Energy(FME contract-number:193818).
文摘An effect of hydropower and hydropeaking regulation in rivers is stranding of fish. Those fishes that survive stranding may experience stranding as a stressful situation. In four experimental stranding experiments (each with 6 individuals in 10 control and 10 treatment replicates), the energetic consequences of two forms of stranding (i.e. trapping and beaching) of juvenile Atlantic salmon (Salmo salar) were investigated in summer and winter. Restricted food access in the experimental channels ensured that effects of hydropeaking could be revealed. Mean fish length ranged between 60 mm and 110 mm among experiments. Both during the winter and summer experiments fish did not grow in length, neither in the control nor in the treatment channels and fish lost body mass as well as body fat in all experiments (body fat in summer trapping experiment not determined). The four experiments revealed similar results: stranding did not affect growth or energy content. Despite the severity of the stranding and the resulting mortality, which was especially high during summer, no stranding related effects on fish performance could be detected.
文摘Experimental infection of fish for vaccine efficacy studies is associated with several limitations. Administration of live bacteria with the purpose of causing disease in fish can be performed by co-habitation, immersion or injection. We have developed a new Aeromonas salmonicida challenge method for rainbow trout and have applied it for evaluation of furunculosis vaccine efficacy. The method reveals development of systemic immunity in fish as live bacteria are introduced in the tail fin epidermis distant from the vaccine injection site (peritoneal cavity). This method seeks to mimic natural infection in fish farms where tail biting and therefore bacterial exposure to tail fin ulcers is widespread. By use of a multi-needle device ten epidermal perforations were introduced in the dorsal part of the tail fin of anaesthetized rainbow trout (vaccinated or naive). Subsequently 100 μL (3.4 × 10<sup>8</sup> colony-forming units (CFU) mL<sup>-1</sup>) of a 48 hour culture of Aeromonas salmonicida subsp. salmonicida strain 090710-1/23 was placed at the perforation site for 60 sec whereafter fish were allowed to regain consciousness in clean freshwater. Immunohistochemistry and scanning electron microscopy illustrated the spread of bacteria from the injection site. Classical furunculosis symptoms associated with a high morbidity rate were observed in control fish whereas vaccinated fish exhibited a significantly higher survival.
文摘This study evaluated the effects of two water velocities and three types of vertically-suspended environmental enrichment during the rearing of juvenile rainbow trout (Oncorhynchus mykiss;mean ± SE, initial weight 4 ± 1 g and total length 71 ± 2 mm) in 1.8m diameter circular tanks. The 2 × 3 experimental design used two velocities (12.2 cm·s-1 and 30.5 cm·s-1) and three structural treatments (aluminum rod array, plastic spheres, or no structure). After 116 days, the fish reared without any structure (control) at 30.5 cm·s-1 had significantly lower total tank weight, gain, percent gain, feed conversion ratio, and specific growth rate compared to the other treatments. Similarly, the fish reared with a velocity of 30.5 cm·s-1 without structure were significantly shorter and lighter than those in the other treatments. There was no significant difference in condition factor and relative fin lengths among the treatments. These results indicate that vertically-suspended environmental enrichment may be impacting fish rearing performance by altering tank water velocities.
文摘Invasive hybridization and introgression pose a serious threat to the persistence of many native species. Understand- ing the effects of hybridization on native populations （e.g., fitness consequences） requires numerous species-diagnostic loci dis- tributed genome-wide. Here we used RAD sequencing to discover thousands of single-nucleotide polymorphisms （SNPs） that are diagnostic between rainbow trout （RBT, Oncorhynchus mykiss）, the world＇s most widely introduced fish, and native westslope cutthroat trout （WCT, （9. clarkii lewisi） in the northern Rocky Mountains, USA. We advanced previous work that identified 4,914 species-diagnostic loci by using longer sequence reads （100 bp vs. 60 bp） and a larger set of individuals （n = 84）. We sequenced RAD libraries for individuals from diverse sampling sources, including native populations of WCT and hatchery broodstocks of WCT and RBT. We also took advantage of a newly released reference genome assembly for RBT to align our RAD loci. In total, we discovered 16,788 putatively diagnostic SNPs, 10,267 of which we mapped to anchored chromosome locations on the RBT genome. A small portion of previously discovered putative diagnostic loci （325 of 4,914） were no longer diagnostic （i.e., fixed between species） based on our wider survey of non-hybridized RBT and WCT individuals. Our study suggests that RAD loci mapped to a draft genome assembly could provide the marker density required to identify genes and chromosomal regions in- fluencing selection in admixed populations of conservation concern and evolutionary interest [Current Zoology 61 （1）： 146-154, 2015].
文摘This experiment evaluated the use of an exercise routine and vertically-sus<span style="font-family:Verdana;">-<span style="font-family:;" "=""><span style="font-family:Verdana;">pended structure during juvenile landlocked fall Chinook salmon (<span style="font-family:Verdana;">Oncor<span style="font-family:Verdana;">hynchus tshawytscha<span style="font-family:Verdana;">;<span style="font-family:;" "=""> <span style="font-family:Verdana;">mean ± SE, initial weight 1.47 ± 0.03 g, total length 56.4 ± 0.4 mm) rearing. Four treatments were used: 1<span style="font-family:Verdana;">)<span style="font-family:Verdana;"> no exercise routine nor vertically-suspended structure, 2<span style="font-family:Verdana;">)<span style="font-family:Verdana;"> exercise and structure, 3<span style="font-family:Verdana;">)<span style="font-family:Verdana;"> exercise and no structure, and 4<span style="font-family:Verdana;">)<span style="font-family:;" "=""><span style="font-family:Verdana;"> no exercise and structure. <span style="font-family:Verdana;">Water velocities in tanks without exercise were 12 cm/s, where-as the exercise routine consisted of seven days at 12 cm/s followed by seven days at 18 cm/s. The structure was an array consisting of four vertically-suspended aluminum angles. Total tank gain and percent gain were significantly greater after 50 days in the tanks of salmon subjected to the exercise routine and structure compared to the three other treatments. <span style="font-family:Verdana;">Gain and percent gain were also significantly greater in the tanks receiving<span style="font-family:Verdana;"> structure without exercise compared to tanks with exercise and no structure or tanks with neither exercise nor structure. Feed conversion ratio was signif<span style="font-family:Verdana;">icantly improved in the salmon tanks with structure and without exercise<span style="font-family:Verdana;"> com<span style="font-family:;" "=""><span style="font-family:Verdana;">pared to all other treatments. There were no significant differences for indi<span style="font-family:Verdana;">vidual fish weight, total length, specific growth rate, or condition factor<span style="font-family:Verdana;"> among any of the treatments at the end of the experiment. <span style="font-family:Verdana;">These results indicate that the use of both an exercise routine and vertically-suspended structure may be beneficial during the rearing of juvenile landlocked fall Chinook salmon.
文摘Eyed salmonid eggs can be subjected to large temperature swings during development, particularly when shipped in ice-filled containers from broodstock facilities to production hatcheries. This study examined the effect of thermal tempering on the survival of brown trout <em>Salmo trutta</em> and rainbow trout <em>Oncorhynchus mykiss</em> eyed eggs to hatch. Eyed eggs at 1<span style="white-space:nowrap;">°</span>C were either directly placed in 11<span style="white-space:nowrap;">°</span>C water or allowed to thermally temper from 1<span style="white-space:nowrap;">°</span>C to 11<span style="white-space:nowrap;">°</span>C gradually over an hour. In addition, each of the tempering treatments occurred either with or without a 10-minute iodophor disinfection treatment. Tempering had no significant effect on survival-to-hatch in either species (85% - 97%). However, survival was significantly lower in rainbow trout eggs subjected to iodine disinfection (73% - 75%) compared to non-disinfected eggs (91% - 97%), likely because of the close proximity to hatch. The results of this study indicate that slowly raising the temperature (thermal tempering) of brown trout and rainbow trout eyed eggs is unnecessary. Additionally, iodine disinfection of eyed salmonid eggs in close proximity to hatching should be avoided.
基金supported by the budgetary state project:Studying of adaptations of organisms,populations,communities of aquatic organisms and modeling ecosystems to environmental factors.State registration No.01201351909.
文摘The review presents data on structural changes,physiological and biochemical reactions occurring at salmon young fishes during smoltification.It is shown,that young salmon fishes located in fresh water,in the process of smoltification undergo a complex of structural,physiological and biochemical changes directed on preparation of the organism for living in the sea.These changes cause stress reaction which excites young fishes to migrate down the river towards the sea.Measures to improve reproduction of young salmon fishes at fish farms are offered.
