Multivariate analysis was adopted to analyze 30 morphometrical characteristics of 121 one-year-old juvenile silver carp （Hypophthalmichthys molitrix） and bighead carp （Aristichthys nobilis） bred during the 1950s ...Multivariate analysis was adopted to analyze 30 morphometrical characteristics of 121 one-year-old juvenile silver carp （Hypophthalmichthys molitrix） and bighead carp （Aristichthys nobilis） bred during the 1950s （＂the former population＂） and 2008 （＂the current population＂） and collected from the middle reach of the Yangtze River. The average discriminant accuracies of the former and current silver and bighead carp population were 94.2% and 98.0%, respectively. Discriminant analysis also revealed that significant differences in morphology occurred between the former and current populations of both carp in overall characteristics. One-way analysis of variance indicated that between former and current populations, silver carp showed highly significant differences （P0.01） in twelve of their characteristics and significant differences （P0.05） in eight of their characteristics, while bighead carp showed highly significant differences （P0.01） in eight of their characteristics and significant differences （P0.05） in eight of their characteristics. Six head morphology variables of the current silver and bighead carp were significantly or highly significantly larger than the former populations; fourteen characteristics of silver carp and ten characteristics of bighead carp of the current populations, mainly reflecting truck and tail morphology, were significantly or very significantly smaller than the former populations. Our results indicate that silver and bighead carp have developed a larger head and smaller truck and tail during the last 50 years. Due to such morphological changes, it seems apparent that the heads of these fish species need to be considered in regards to human diets, particularly in relation to economic and nutritious value.展开更多
Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suc...Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suction volume was much greater than the former’s so the filtering rate(filtering frequency mul-tiplied by the suction volume)of silver carp was smaller than that of bighead carp.The filtering efficien-cy of silver carp for phytoplankton was greater than that of bighead carp for them.The removal ratesof silver carp for phytoplankton were greater than those of bighead carp,but for zooplankton the formerwere smaller than the latter.For food particles about 70 μm both removal rates were almost equal.The feeding habits of the two species in natural waters is also discussed in the paper.展开更多
Myosin subfragment-1 was prepared from the myofibrils of bighead carp (Aristichthys nobilis). The myosin subfrag- ment-1 was proved to have the activity of tripolyphosphatase (TPPase) responding to the hydrolysis of s...Myosin subfragment-1 was prepared from the myofibrils of bighead carp (Aristichthys nobilis). The myosin subfrag- ment-1 was proved to have the activity of tripolyphosphatase (TPPase) responding to the hydrolysis of sodium tripolyphosphate (STPP). The optimum temperature and pH for the TPPase of myosin subfragment-1 were 30℃ and pH 5.0, and at pH 8.0 the TPPase also showed a high activity. Mg2+ was necessary to TPPase. The TPPase activity of myosin subfragment-1 was activated by Mg2+ under low concentrations, but was inhibited when the concentration was over 17 mmolL-1. The TPPase activity was also affected by KCl. The optimum concentration of KCl for TPPase was 0.3 molL-1 under the condition of 17 mmolL-1 Mg2+. The TPPase activity was significantly inhibited by EDTA-Na2. Reagents such as KBr, KI and KIO3 could inhibit the TPPase effectively. K2Cr2O7 as well as KMnO7 and KNO3 exhibited weak inhibiting effects. The TPPase converted STPP to pyrophosphate (PP) and orthophosphate (Pi) stoichiometrically with a KM of 3.2 mmolL-1.展开更多
Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of t...Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of tilapia(Oreochromis mossambicus)and bighead carp(Aristichthys nobilis)from Hongchaojiang Reservoir in Guangxi,China were investigated by ITS sequencing.Based on this,we obtained 1763478 high-quality tags,which clustered into 1089 operational taxonomic units(OTUs).In total,404 OTUs were annotated,of which 310,68,and 26 belonged to Ascomycota,Basidiomycota,and other,respectively.Results show significant differences in the community composition of intestinal fungi between tilapia and bighead carp but not within their different intestinal segments.Furthermore,154 of the 404 annotated OTUs were considered reliable and were classified into three trophic modes and nine guilds.The three trophic modes consisted of 108 OTUs of saprotrophic fungi,41 OTUs of pathotrophic fungi,and five OTUs of symbiotrophic fungi.The top three most abundant OTUs overall(i.e.,Otu000002,Scopulariopsis acremonium;Otu000018,Alternaria palandui;Otu000034,Aureobasidium pullulans)showed lower abundance in the hind-intestinal segments of bighead carp,suggesting uneven distribution of these fungi in this species.In addition,saprotrophic and pathotrophic fungi were markedly decreased in the hindintestine.It is indicated that the fungal community was not only related to host species specificity but also to the respective physiological functions of different intestinal segments.These findings provide valuable information on the composition,structure,and potential function of the intestinal fungi community associated with different intestinal segments in tilapia and bighead carp under natural conditions,thus highlighting the importance of fungi as an integral part of the inte stinal microbiota in maintaining host health.展开更多
The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquat...The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquatic organisms and aquatic environment. The results showed that the development of bighead and silver carp embryos was delayed, the mortality and abnormality rates were raised when the embryos were treated with ≥0.010 mg·L^-1 nitrobenzene, and with ≥0.085 mg· L^-1 nitrobenzene, the mortality rates showed 100%展开更多
The relationship between crustacean zooplankton and(planktivorous)fish has not been well clarified in bigheaded-carps-dominated reservoirs,for most of the past studies to explore that kind of knowledge above are often...The relationship between crustacean zooplankton and(planktivorous)fish has not been well clarified in bigheaded-carps-dominated reservoirs,for most of the past studies to explore that kind of knowledge above are often obtained from the studies in temperate lakes and/or shallow lakes.The limitation of these studies is that crustacean zooplankton lack of either large grazers such as the bigheaded carps or the vertical migrating space for zooplankton to avoid predation by planktivorous fish.Reservoirs are more and more important drinking water source for human consumption,so a better environmental management of reservoirs will rely on a better understanding on the relationship between zooplankton and fish in bigheaded carp dominated reservoirs.To help reach that goal,we investigated the structure and variation of zooplankton and studied the relationship between zooplankton and fish in Tangpu reservoir,Zhejiang province,China.Our results showed that the species of crustacean zooplankton were richer.A total of 59 species of crustacean zooplankton were detected,including 33 species of copepods and 26 species of cladoceran,and dominated by larger species.The density of crustacean zooplankton varied between 15.5–68.5 ind./L with an annual average density of 24.9±14.4 ind./L,it is higher in this planktivorous carps dominated deep reservoir than in many carp-less-dominated reservoirs or in shallow lakes.We also found that zooplankton and fish had a differential vertical distribution,i.e.,zooplankton occurred 5 m–10 m but fish occurred 0.5 m–10 m in many months of the year.This could well explain why zooplankton were not reduced and not dominated by small species in bigheaded carps dominated reservoir,so we concluded that in planktivorous carp dominated deep reservoir ecosystems,zooplankton might not compete directly with planktivorous carps for phytoplankton,instead by distributing or migrating to deeper water column,they may survive and thrive on the phytoplankton in deeper column and the detritus resulted from the feces of planktivorous fish,thus might be able to coordinately improve water quality with planktivorous fish.展开更多
Background Since the late 1990s,bigheaded carps(largely silver carp[Hypophthalmichthys molitrix]but also bighead carp[H.nobilis])have established throughout the lower Mississippi River basin.Using previously studied o...Background Since the late 1990s,bigheaded carps(largely silver carp[Hypophthalmichthys molitrix]but also bighead carp[H.nobilis])have established throughout the lower Mississippi River basin.Using previously studied oxbow lakes in the lower White River basin,Arkansas,we compared current(2017,“post-carp”establishment)fish assemblages to historical(2002,“pre-carp”establishment)fish assemblages.Fish assemblages were comprehensively assessed using multiple gears,including boat electrofishing,mini-fyke nets,and experimental small-mesh gill nets.Results T-tests suggested that fish assemblage indices of richness,diversity,evenness,and dominance were often greater(P<0.05)during the post-carp period as reflected by boat electrofishing and experimental gill nets.However,all indices were generally similar(P>0.05)between the pre-carp and post-carp period with fish assemblages depicted using mini-fyke nets.Nonmetric multidimensional scaling analyses indicated that fish assemblages differed structurally between pre-carp and post-carp periods.Assemblage differences were linked to both small and large abundance changes for more than 20 species.Abundances of gizzard shad(Dorosoma cepedianum),emerald shiner(Notropis atherinoides),pugnose minnow(Opsopoeodus emiliae),crappies(Pomoxis spp.),bluegill(Lepomis macrochirus),orangespotted sunfish(L.humilis),and yellow bass(Morone mississippiensis)declined between the pre-carp and postcarp periods.Conversely,abundances of weed shiner(N.texanus),pallid shiner(Hybopsis amnis),longear sunfish(L.megalotis),buffalofishes(Ictiobus spp.),and gars(Lepisosteus spp.)generally increased during the same period.Conclusions Although not possible to conclude assemblage shifts were entirely related to bigheaded carps due to the absence of an appropriate reference system where carps did not establish,the wide establishment of these carps is one of the most pervasive changes to have occurred in the lower White River ecosystem during the past two decades.Thus,it is probable to conclude that post-carp establishment observations from this study were at least,in part,attributable to bigheaded carp establishment.Impacts of further range expansions by bigheaded carps in the White River and other lower Mississippi River sub-basins are unclear,though this study suggests probable effects on native fish assemblages,underscoring the need for further research and monitoring.展开更多
Silver carp, Hypophthalmichthys molitrix, and bighead carp, Aristichthys nobilis, habitually celebrated for their being cultured easily with fewer diseases and high-yield, have suffered from a new severe epidemic dise...Silver carp, Hypophthalmichthys molitrix, and bighead carp, Aristichthys nobilis, habitually celebrated for their being cultured easily with fewer diseases and high-yield, have suffered from a new severe epidemic disease recently. The spread of the epizootic has been far and wide, from several provinces in South China to the Beijing and Tianjin area. The affected fish suffered heavy mortafity in one week, and even died off.展开更多
基金National Natural Science Foundation of China (30630051)Aquaculture E-Institute of Shanghai Universities(03E009)Shanghai Leading Academic Discipline Project(S30701)
文摘Multivariate analysis was adopted to analyze 30 morphometrical characteristics of 121 one-year-old juvenile silver carp （Hypophthalmichthys molitrix） and bighead carp （Aristichthys nobilis） bred during the 1950s （＂the former population＂） and 2008 （＂the current population＂） and collected from the middle reach of the Yangtze River. The average discriminant accuracies of the former and current silver and bighead carp population were 94.2% and 98.0%, respectively. Discriminant analysis also revealed that significant differences in morphology occurred between the former and current populations of both carp in overall characteristics. One-way analysis of variance indicated that between former and current populations, silver carp showed highly significant differences （P0.01） in twelve of their characteristics and significant differences （P0.05） in eight of their characteristics, while bighead carp showed highly significant differences （P0.01） in eight of their characteristics and significant differences （P0.05） in eight of their characteristics. Six head morphology variables of the current silver and bighead carp were significantly or highly significantly larger than the former populations; fourteen characteristics of silver carp and ten characteristics of bighead carp of the current populations, mainly reflecting truck and tail morphology, were significantly or very significantly smaller than the former populations. Our results indicate that silver and bighead carp have developed a larger head and smaller truck and tail during the last 50 years. Due to such morphological changes, it seems apparent that the heads of these fish species need to be considered in regards to human diets, particularly in relation to economic and nutritious value.
文摘Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suction volume was much greater than the former’s so the filtering rate(filtering frequency mul-tiplied by the suction volume)of silver carp was smaller than that of bighead carp.The filtering efficien-cy of silver carp for phytoplankton was greater than that of bighead carp for them.The removal ratesof silver carp for phytoplankton were greater than those of bighead carp,but for zooplankton the formerwere smaller than the latter.For food particles about 70 μm both removal rates were almost equal.The feeding habits of the two species in natural waters is also discussed in the paper.
基金This work was supported by the National Natural Science Foundation of China （No. 30671632）supported by the National High-tech Research and Development Project of China （No. 2006AA09Z444）.
文摘Myosin subfragment-1 was prepared from the myofibrils of bighead carp (Aristichthys nobilis). The myosin subfrag- ment-1 was proved to have the activity of tripolyphosphatase (TPPase) responding to the hydrolysis of sodium tripolyphosphate (STPP). The optimum temperature and pH for the TPPase of myosin subfragment-1 were 30℃ and pH 5.0, and at pH 8.0 the TPPase also showed a high activity. Mg2+ was necessary to TPPase. The TPPase activity of myosin subfragment-1 was activated by Mg2+ under low concentrations, but was inhibited when the concentration was over 17 mmolL-1. The TPPase activity was also affected by KCl. The optimum concentration of KCl for TPPase was 0.3 molL-1 under the condition of 17 mmolL-1 Mg2+. The TPPase activity was significantly inhibited by EDTA-Na2. Reagents such as KBr, KI and KIO3 could inhibit the TPPase effectively. K2Cr2O7 as well as KMnO7 and KNO3 exhibited weak inhibiting effects. The TPPase converted STPP to pyrophosphate (PP) and orthophosphate (Pi) stoichiometrically with a KM of 3.2 mmolL-1.
基金the Guangxi Science and Technology Major Project(No.AA17204095-8)the Open Fund of Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture(No.GXKEYLA2019-05)the China-ASEAN Maritime Cooperation Fund(No.CAMC-2018F)。
文摘Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of tilapia(Oreochromis mossambicus)and bighead carp(Aristichthys nobilis)from Hongchaojiang Reservoir in Guangxi,China were investigated by ITS sequencing.Based on this,we obtained 1763478 high-quality tags,which clustered into 1089 operational taxonomic units(OTUs).In total,404 OTUs were annotated,of which 310,68,and 26 belonged to Ascomycota,Basidiomycota,and other,respectively.Results show significant differences in the community composition of intestinal fungi between tilapia and bighead carp but not within their different intestinal segments.Furthermore,154 of the 404 annotated OTUs were considered reliable and were classified into three trophic modes and nine guilds.The three trophic modes consisted of 108 OTUs of saprotrophic fungi,41 OTUs of pathotrophic fungi,and five OTUs of symbiotrophic fungi.The top three most abundant OTUs overall(i.e.,Otu000002,Scopulariopsis acremonium;Otu000018,Alternaria palandui;Otu000034,Aureobasidium pullulans)showed lower abundance in the hind-intestinal segments of bighead carp,suggesting uneven distribution of these fungi in this species.In addition,saprotrophic and pathotrophic fungi were markedly decreased in the hindintestine.It is indicated that the fungal community was not only related to host species specificity but also to the respective physiological functions of different intestinal segments.These findings provide valuable information on the composition,structure,and potential function of the intestinal fungi community associated with different intestinal segments in tilapia and bighead carp under natural conditions,thus highlighting the importance of fungi as an integral part of the inte stinal microbiota in maintaining host health.
文摘The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquatic organisms and aquatic environment. The results showed that the development of bighead and silver carp embryos was delayed, the mortality and abnormality rates were raised when the embryos were treated with ≥0.010 mg·L^-1 nitrobenzene, and with ≥0.085 mg· L^-1 nitrobenzene, the mortality rates showed 100%
文摘The relationship between crustacean zooplankton and(planktivorous)fish has not been well clarified in bigheaded-carps-dominated reservoirs,for most of the past studies to explore that kind of knowledge above are often obtained from the studies in temperate lakes and/or shallow lakes.The limitation of these studies is that crustacean zooplankton lack of either large grazers such as the bigheaded carps or the vertical migrating space for zooplankton to avoid predation by planktivorous fish.Reservoirs are more and more important drinking water source for human consumption,so a better environmental management of reservoirs will rely on a better understanding on the relationship between zooplankton and fish in bigheaded carp dominated reservoirs.To help reach that goal,we investigated the structure and variation of zooplankton and studied the relationship between zooplankton and fish in Tangpu reservoir,Zhejiang province,China.Our results showed that the species of crustacean zooplankton were richer.A total of 59 species of crustacean zooplankton were detected,including 33 species of copepods and 26 species of cladoceran,and dominated by larger species.The density of crustacean zooplankton varied between 15.5–68.5 ind./L with an annual average density of 24.9±14.4 ind./L,it is higher in this planktivorous carps dominated deep reservoir than in many carp-less-dominated reservoirs or in shallow lakes.We also found that zooplankton and fish had a differential vertical distribution,i.e.,zooplankton occurred 5 m–10 m but fish occurred 0.5 m–10 m in many months of the year.This could well explain why zooplankton were not reduced and not dominated by small species in bigheaded carps dominated reservoir,so we concluded that in planktivorous carp dominated deep reservoir ecosystems,zooplankton might not compete directly with planktivorous carps for phytoplankton,instead by distributing or migrating to deeper water column,they may survive and thrive on the phytoplankton in deeper column and the detritus resulted from the feces of planktivorous fish,thus might be able to coordinately improve water quality with planktivorous fish.
基金U.S.Fish and Wildlife Service—Gulf States Marine Fisheries Commission through the Gulf&Atlantic Regional Panel on Aquatic Invasive Speciesthe U.S.Fish and Wildlife Service—Lower Mississippi River Conservation CommitteeAdditional financial support and facilities were provided by the Aquaculture/Fisheries Center at the University of Arkansas at Pine Bluff(UAPB)
文摘Background Since the late 1990s,bigheaded carps(largely silver carp[Hypophthalmichthys molitrix]but also bighead carp[H.nobilis])have established throughout the lower Mississippi River basin.Using previously studied oxbow lakes in the lower White River basin,Arkansas,we compared current(2017,“post-carp”establishment)fish assemblages to historical(2002,“pre-carp”establishment)fish assemblages.Fish assemblages were comprehensively assessed using multiple gears,including boat electrofishing,mini-fyke nets,and experimental small-mesh gill nets.Results T-tests suggested that fish assemblage indices of richness,diversity,evenness,and dominance were often greater(P<0.05)during the post-carp period as reflected by boat electrofishing and experimental gill nets.However,all indices were generally similar(P>0.05)between the pre-carp and post-carp period with fish assemblages depicted using mini-fyke nets.Nonmetric multidimensional scaling analyses indicated that fish assemblages differed structurally between pre-carp and post-carp periods.Assemblage differences were linked to both small and large abundance changes for more than 20 species.Abundances of gizzard shad(Dorosoma cepedianum),emerald shiner(Notropis atherinoides),pugnose minnow(Opsopoeodus emiliae),crappies(Pomoxis spp.),bluegill(Lepomis macrochirus),orangespotted sunfish(L.humilis),and yellow bass(Morone mississippiensis)declined between the pre-carp and postcarp periods.Conversely,abundances of weed shiner(N.texanus),pallid shiner(Hybopsis amnis),longear sunfish(L.megalotis),buffalofishes(Ictiobus spp.),and gars(Lepisosteus spp.)generally increased during the same period.Conclusions Although not possible to conclude assemblage shifts were entirely related to bigheaded carps due to the absence of an appropriate reference system where carps did not establish,the wide establishment of these carps is one of the most pervasive changes to have occurred in the lower White River ecosystem during the past two decades.Thus,it is probable to conclude that post-carp establishment observations from this study were at least,in part,attributable to bigheaded carp establishment.Impacts of further range expansions by bigheaded carps in the White River and other lower Mississippi River sub-basins are unclear,though this study suggests probable effects on native fish assemblages,underscoring the need for further research and monitoring.
文摘Silver carp, Hypophthalmichthys molitrix, and bighead carp, Aristichthys nobilis, habitually celebrated for their being cultured easily with fewer diseases and high-yield, have suffered from a new severe epidemic disease recently. The spread of the epizootic has been far and wide, from several provinces in South China to the Beijing and Tianjin area. The affected fish suffered heavy mortafity in one week, and even died off.
