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1.
ABSTRACT:   Prey fish selection by Far Eastern catfish and largemouth bass were examined using bluegill, Japanese dace and crucian carp as food fish. In both aquaria (1.2 m × 0.45 m) and ponds (2.8 m × 1.2 m), bluegill was not preyed on by catfish and bass more than dace and crucian carp. In aquaria, there was no significant difference in the consumption of dace and crucian carp between catfish and bass, but in ponds, catfish preyed on dace and crucian carp more and less than bass, respectively. In the case that only bluegill and catfish were introduced in ponds, catfish consumed 4–15 g of bluegill per day. The introduction of catfish into ponds and lakes for the purpose of eradicating bluegill is considered appropriate for areas with few native fish species.  相似文献   

2.
Channel catfish virus (CCV) disease is an acute haemorrhagic disease in juvenile channel catfish ( Ictalurus punctatus ). To date channel catfish is the only species affected by natural outbreaks of the CCV but juvenile large mouth bass ( Micropterus salmoides ) and silurus ( Silurus meriaionalis ) have suffered high mortalities in recent years in China. Histopathological phenomenon of sick fish is similar to CCV disease, and the identified virus was CCV. In this report, the pathogenicity of infectious CCV was examined by infection trials on the first known host species, the channel catfish and other teleosts. Our results indicated that there were higher detection rates of CCV from large mouth bass and silurus fish. Channel catfish virus did not induce mortality in other cypriniformes, but histopathological studies revealed that carp might be infected by both bathing and intraperitoneal infection. No deaths, clinical or histopathological signs, were found in the six other species exposed by immersion or injection. Experimental infection studies confirm that CCV infect not only channel catfish but also other species (large mouth bass, silutus and carp). The outbreaks of CCV disease only occurred when the cultured temperature was above 25 °C.  相似文献   

3.
Uptake and clearance of Edwardsiella ictaluri in the peripheral blood of channel catfish Ictalurus punctatus fingerlings were monitored for 216 h after exposure to E. ictaluri for 4 h and 8 h under static conditions. Most fish exposed to E. ictaluri developed bacteriemia 24 h post-exposure, and by 72 h post-exposure E. ictaluri was recovered from all the blood of all exposed fish. The number of E. ictaluri colony forming units (CFU) in the blood of moribund fish ranged between 1.7 × 103 to 1.6 × 105 CFU/50 μL whole blood. Clearance of bacteria from the blood was observed by 216 h post-exposure and all fish surviving bacterial exposure developed agglutinating antibody against E. ictaluri . The pathogenesis of the infection was accompanied by the shedding of viable E. ictaluri into the water which may serve as a mechanism by which fish to fish transmission occurs.  相似文献   

4.
There has been strong interest in the use of peracetic acid (PAA) in aquaculture as it can be used to disinfect water and hard surfaces and thereby eliminate or lower the burden of fish pathogens. Unfortunately, there has been little research on the toxicity of PAA to fish. Twelve species of fingerling fish that are important to aquaculture were exposed to PAA for 24 h in static toxicity bioassays in well water. These fish were: fathead minnow, Pimephales promelas; black‐nose crappie, Pomoxis nigromaculatus; bluegill, Lepomis macrochirus; blue tilapia, Oreochromis aureus; channel catfish, Ictalurus punctatus; golden shiner, Notemigonus crysoleucas; goldfish, Carassius auratus; grass carp, Ctenopharyngodon idella; largemouth bass, Micropterus salmoides; rainbow trout, Oncorhynchus mykiss; sunshine bass, Morone chrysops × M. saxatilis; and walleye, Sander vitreus. Median lethal concentration (LC50) values were estimated with the trimmed Spearman–Karber method using nominal PAA concentrations. The mean 24‐h LC50 values ranged from 2.8 to 9.3 mg/L PAA. Fathead minnow were very sensitive and blue tilapia were very tolerant to PAA exposure; LC50 values of other species tested were within the range of 4.1–6.2 mg/L PAA. More importantly, the 24‐h no‐observed‐effect concentration (NOEC) ranged from 1.9 to 5.8 mg/L PAA; the NOEC would be considered as the safe range for culturists to investigate the use of PAA. Decreased alkalinity/hardness increased the toxicity of PAA, while a small increase of dissolved organic content had no effect on PAA toxicity. Results of the present study are important information on the safe application of PAA for the aquaculture industry.  相似文献   

5.
Abstract— Alternative fish species that can be cultured together with catfish Ictalurus punctatus provide an opportunity to diversify caffish farms. A 2-yr study was conducted in 0.10-ha earthen ponds to evaluate the effect of bighead carp (BHC) stocking density on growth, yield, dressout yield, and net returns. Initially, bighead carp (average weight of 22 g) were stocked at rates of 380, 750, or 1,130 fishha in ponds with catfish. Caffish were cultured under commercial conditions by stocking caffish at a density of 12,500/ha, aerating nightly and feeding at an average rate of 82 kgha per d. Stocking rates for 2-yr-old fish were reduced to 77, 260, and 435/ha in the second growing season. There were no significant differences among treatments ( P > 0.05) in summer growth of bighead carp in either year. Bighead carp stocked at 1,130 fishha had significantly higher yields than those stocked at 380/ha, but did not reach minimum market size of 2.2 kg during the first year ( P > 0.05). There were no significant differences ( P > 0.05) in caffish growth, yield, survival, or feed conversion ratios due to the bighead carp stocking densities. Partial budget analysis indicated that net benefits were positive for all three treatments over a range of prevailing prices of bighead carp. Bighead carp production in catfish ponds is economically feasible over a wide range of prices. Given the market risk of producing smaller fish at the higher density, the medium density is the preferred stocking density of fingerling bighead carp in catfish ponds.  相似文献   

6.
Abstract  Standard methods for comparing population characteristics within and among fish populations greatly enhance communications among fisheries scientists, improve the efficiency of data analysis, and provide insight that helps guide management actions. Although standard methods are available for comparing some fish population characteristics (e.g. length structure, body condition), similar methods are lacking for comparing growth. The purpose of this study was to provide standards (i.e. percentiles and a standard growth model) for nine ecologically and recreationally important fish species. Percentile distributions of mean back-calculated length at age were estimated using data obtained from the published literature and from data solicited from state and federal agencies throughout North America. Percentiles of growth were estimated for bluegill, Lepomis macrochirus Rafinesque, common carp, Cyprinus carpio Linnaeus, flathead catfish, Pylodictis olivaris (Rafinesque), largemouth bass, Micropterus salmoides (Lacepède), sauger, Sander canadensis (Griffith & Smith), smallmouth bass, Micropterus dolomieu Lacepède, white bass, Morone chrysops (Rafinesque) and yellow perch, Perca flavescens (Mitchill). Standard growth models (i.e. von Bertalanffy models) were developed for these species and for channel catfish, Ictalurus punctatus (Rafinesque). These results provide tools that will help scientists compare growth of fishes across North America.  相似文献   

7.
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8.
Fine ML, Mayo MS, Newton SH, Sismour EN. Largemouth bass predators reduce growth, feeding and movement in juvenile channel catfish. Ecology of Freshwater Fish 2011: 20: 114–119. © 2010 John Wiley & Sons A/S Abstract – Animals utilise sensory cues to make decisions that will decrease their vulnerability to predation. With a well‐developed olfactory system and taste buds located inside the mouth and on the external body surface, catfishes are excellent subjects to investigate nonconsumptive predator effects. Juvenile channel catfish Ictalurus punctatus are often eaten by largemouth bass Micropterus salmoides, and we tested the hypothesis that largemouth bass fed catfish would adversely affect foraging and growth in channel catfish. Groups of catfish were placed in tanks partitioned by a mesh screen: experimental tanks had a largemouth bass on the other half of the tank, and control tanks had an empty chamber. Experimental catfish exhibited a long‐term decrease in spontaneous motion, feeding and growth. Feeding catfish to the bass caused the experimental catfish to freeze after a multi‐second latency suggesting transport of an alarm cue. Thus, there were long‐term effects from the continuous presence of the bass and additional short‐term cues from the bass consuming a catfish.  相似文献   

9.
Francisella orientalis is a highly virulent, emerging bacterium that causes mass mortalities in tilapia. This pathogen also affects numerous other warm-water fish species, including three-line grunt, hybrid striped bass and various ornamental fish. This study sheds light on two new species of fish that are susceptible to F. orientalis. Asian seabass and largemouth bass showed variable levels of susceptibility in a bacterial challenge experiment. After intraperitoneally injected with a dose of 106 CFU/fish, a total of 64.28% and 21.42% mortalities were obtained in Asian seabass and largemouth bass, respectively. Meanwhile, Nile tilapia showed acute mortality of 100%. All fish showed typical lesions of francisellosis, including multifocal granulomas in the spleen and head kidney. Immunohistochemical analysis revealed strong positive signals inside the granulomas of all fish. The bacterial recovery in solid media from infected fish was highest in Nile tilapia (85.71%), followed by Asian seabass (35.71%) and largemouth bass (21.42%). PCR results tested 100% positive for Nile tilapia, and 78.57% and 21.42% for Asian seabass and largemouth bass, respectively. In conclusion, Asian seabass and largemouth bass are susceptible to this pathogen, which warrants new management strategies when employing predation polyculture systems of these species with tilapia.  相似文献   

10.
Mycobacteriosis in fish can result in ulcers, emaciation, and in some cases death. Mycobacteria have been previously isolated from a variety of Chesapeake Bay fish species, and the current study was designed to identify potential host specificity and location fidelity of mycobacterial isolates. Mycobacteria were isolated from wild fish of the Chesapeake Bay collected from the Upper Bay, the Choptank River, Herring Bay, the Chicamacomico River, the Pocomoke River and the Potomac River in 2003–2006. Mycobacterial isolates were recovered from striped bass, Morone saxatilis , Atlantic menhaden, Brevoortia tyrannus , white perch, Morone americana , summer flounder, Paralichthys dentatus , spot, Leiostomus xanthurus , largemouth bass, Micropterus salmoides , channel catfish, Ictalurus punctatus , common carp, Cyprinus carpio carpio , spotted seatrout, Cynoscion nebulosus , killifish, Fundulus sp., blueback herring, Alosa aestivalis , American gizzard shad, Dorosoma cepedianum and American silver perch, Bairdiella chrysoura . Twenty-nine well-defined mycobacterial groups resulted from gas chromatography dendrogram clustering of isolates. The majority of groups included more than one host species and more than one site of collection. However, four groups contained only striped bass isolates, three of which were similar to M. shottsii . Therefore, multiple Chesapeake Bay fish species are colonized with multiple mycobacterial isolates, of which few appear to be host or location specific.  相似文献   

11.
Growth of second-year triploid and diploid bighead carp, Hypophthalmichthys nobilis, was compared in a 189- to 190-day yield trial; the fish were grown separately in 0.04-ha earthen ponds at 625/ha and were also grown communally in 0.05-ha earthen ponds at 640ha. When grown communally, bighead carp were polycultured with channel catfish, Ictalurus punctatus (7,50Oha), and grass carp, Cienopharyngodon idella (40/ha); when they were grown separately, they were polycultured with grass carp at 501ha. When cultured separately, diploids were longer (526 vs 499 mm) and heavier (1,645 vs 1,427 g) than the triploids at harvest, but the differences were not significant (P 5 0.05). When cultured communally, the diploids were significantly longer (519 vs 485 mm) and heavier (1,621 vs 1,321 g) than their triploid counterparts at harvest. Ploidy of all bighead carp was determined after fish were harvested, and 7.9% of the presumed triploids that were stocked separately were actually diploids. Growth of the triploids appeared to be acceptable for commercial use where diploid bighead carp are banned. The efficiency of producing triploid bighead carp must be improved if they are to be cultured in states where bighead carp are illegal.  相似文献   

12.
These studies were conducted to evaluate the efficacy of a live attenuated Edwardsiella ictaluri vaccine against enteric septicemia of catfish. In one study channel catfish fingerlings (72 d of age post hatch) were immersed for 30 min in water containing E. ictaluri RE-33 at dosages of 1 × 106, 1 × 107 and 2 × 107 CFU/ML of water. No mortalities were observed following vaccination. Following exposure to virulent Edwardsiella ictaluri the cumulative mortality of fish vaccinated with dosages of at least 1 × 107 CFU/mL were significantly lower than that of non-vacccinated fish in both laboratory and field challenges. Vaccination with 1 × 106 CFU RE-33mL provided some protection during the laboratory challenge but failed to protect fish under field conditions. In a second study, vaccination of 6 full-sib families of channel catfish at a vaccine dosage of 1 × 107 CFU/mL resulted in a relative percent survival among families ranging from 67.1 to 100%. Significant differences in mortality were found among families and between vaccinated and unvaccinated groups, but there was no family by vaccine interaction. Families with the highest mortality after vaccination were also shown to have the highest mortality without vaccination (r = 0.82; P = 0.04).  相似文献   

13.
Nutritional amino acid requirements of varying size classes of largemouth bass were estimated using A/E ratios. Nutrient and amino acid contents of roe and carcass of the different size classes were determined and compared to results of selected, classic works related to the concept of ideal protein and relationship between the contents of individual, essential amino acids and the total contents of essential amino acids – A/E ratios. Protein content in the roes of the largemouth bass were higher in comparison to the carcass, but the content of lipids of the roes and of the carcass didn’t present significant difference (P<0.05). Largemouth bass showed higher muscle protein content in comparison to other species. Although some authors report variation in the contents of some amino acids in the carcass of selected species, differences observed in this study regarding carcass amino acid contents of tilapia, speckled catfish and largemouth bass were not significant (P<0.05), values of the ratio A/E followed the same trend. Results, herein presented, indicate that the amino acid profile of largemouth bass could be used as complementary tool for balancing amino acids in formulated feed for the species, and in the validation of amino acid requirements determined in performance studies.  相似文献   

14.
Edwardsiella ictaluri is a primary bacterial pathogen of channel catfish, Ictalurus punctatus, and the causative agent of enteric septicaemia of catfish . Edwardsiella ictaluri is known to gain entry to the host by infection of the nares, gastrointestinal tract, and gills, and to disseminate to organs via an as yet uncharacterized acute bacteraemia. In this study, fluorescent microscopy showed E. ictaluri on the gill within 5 min of immersion challenge and E. ictaluri could also be isolated from the circulation within 5 min. When removed to clean water, catfish cleared circulating bacteria within 15 min and the blood remained free of E. ictaluri until its reappearance at the 12 h post-infection sampling. However, Aeromonas hydrophila , the aetiological agent of motile aeromonad septicaemia, appeared within the circulation 7 h post-challenge with E. ictaluri and was detected in all fish at 12 h post-infection. Only 20% of fish carried A. hydrophila in the trunk kidney that could be detected by plate culture on Rimler–Shotts agar; however, 100% of challenged and stress-control fish were A. hydrophila complex positive at 24 h post-challenge. These results suggest that although the catfish is capable of clearing its circulation of E. ictaluri , superinfection with latent A. hydrophila may enhance clinical signs of edwardsiellosis. This is the first report of a bacterial superinfection appearing in fish.  相似文献   

15.
A 74‐day experiment was conducted to evaluate the production performance and water quality variation in three types of farming system for largemouth bass Micropterus salmoides. The tested aquaculture models included monoculture of largemouth bass (MC), polyculture of largemouth bass, gibel carp Carassius auratus gibelio and silver carp Hypophthalmichthys molitrix (PC), and integrated culture of largemouth bass, gibel carp, silver carp and freshwater pearl mussel Hyriopsis cumingii (IC). The ratio of largemouth bass, gibel carp and silver carp was 30:2:1 in the PC model, and the ratio of largemouth bass, gibel carp, silver carp and mussel was 30:2:1:5 in the IC model. The largemouth bass were fed with formulated feed twice daily. No significant differences were found in weight gain and yield of largemouth bass, total fish yield, nitrogen (N) and phosphorus (P) utilization efficiencies, N and P wastes, pH, nitrite, nitrate, reactive phosphate, total nitrogen, total phosphorus, total organic carbon, chemical oxygen demand, 5‐day biochemical oxygen demand, chlorophyll a, primary productivity among the MC, PC and IC models. The ammonia was lower, while the dissolved oxygen was higher in the PC tanks than in the MC tanks. These results suggest that the environment situation was better in the PC tanks relative to that in the MC tanks. The present study reveals that the PC model should be a way to optimize the aquaculture model for commercial largemouth bass farming.  相似文献   

16.
Juveniles from all possible crosses among USDA 102. USDA 103, and Norris channel catfish Ictalurus punctatus strains were compared for: 1) survival and mix-Edwardsiella ictaluri antibody after exposure to live E. ictaluri bacterium (isolate 597-458); 2) antibody level after injection with formalin-killed E. ictaluri (597-458); and 3) pre-stress. post-stress, and stress-recovery serum Cortisol levels. Purebred and crossbred USDA 102 strain fish had higher survival (mean of five genetic groups = 87%) and lower anti- E.ictaluri antibody (mean optical density (OD) of five genetic groups = 0.167) 30 d after live E. ictaluri challenge than purebred Norris and USDA 103 strains and their crosses (means of four genetic groups = 60% survival and 0.210 OD antibody level). Significant general combining ability, line effects, and heterosis indicated that the USDA 102 strain contributed additive and dominance genetic effects for increased survival and lower antibody level after live E. ictaluri challenge. Antibody response to formalin-killed, intra-peritoneally injected E. ictaluri was not different among genetic groups (overall mean = 0.198 OD). Serum Cortisol was measured prior to (pre-stress), immediately after (post-stress), and 2 h after (stress-recovery) a standard stressor. Serum Cortisol level was highest in post-stress fish (35.8 ng/mL), intermediate in stress-recovery fish (10.9 ng/mL), and lowest in pre-stress fish (6.5 ng/mL), but was not different among genetic groups within a stress time period. Results indicate diat differences exist among genetic groups of channel catfish for survival and antibody production after live E. ictaluri challenge, but these differences were not related to antibody response to killed E. ictaluri or serum Cortisol levels.  相似文献   

17.
Abstract. Monoclonal antibodies were made against the reference strain of Edwardsiella ictaluri (ATCC 3320). Antibody produced by one of seven anti- E. ictaluri hybridomas reacted positively by the immunofluorescent antibody technique against 17 other E. ictaluri isolates. All hybridoma antibodies failed to react with six other bacterial species pathogenic to fish including E. tarda . Ouchterlony tests indicated that four anti- E. ictaluri clones produced only one kind of immunoglobulin. Electrophoresis of 14 different E. ictaluri isolates indicated identical protein bands at 36 and 60 kilodaltons (KD) in all isolates except an isolate from Thailand. Using the immunoblot method, channel catfish anti- E. ictaluri serum reacted with protein bands at 34 and 60 KD, which indicates that this molecular weight protein in the bacterium may be the dominant immunoprotein.  相似文献   

18.
Cross-protection of channel catfish ( Ictalurus punctatus Rafinesque) immunized with a low dose of virulent Edwardsiella ictaluri and challenged with six E. ictaluri strains was examined in four trials. The relative per cent survival among low-dose immunized and then challenged fish ranged from 27.7% to 100%. Significant protection ( P <0.05), with the exception of strain ATCC-33202, was conferred by immunization with a given E. ictaluri strain challenged either with a homologous or a heterologous strain. Antibody titres of pooled serum collected on day 22 from surviving fish examined by enzyme-linked immunosorbent assay (ELISA) ranged from 1:40 to 1:320, but no differences were apparent among different vaccinated groups. The protein profiles of six E. ictaluri strains examined by Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a relatively homogeneous pattern. Immuno-blots probed with pooled serum from immunized and challenged fish showed a pattern similar to LPS-reaction patterns observed with E. ictaluri in other studies. Since the present studies further corroborate that E. ictaluri is a clonal bacterial species with no apparent antigenic differences, it is possible that immunization with a single E. ictaluri field strain should confer protection against any other strain.  相似文献   

19.
采用电子显微镜观察和细胞培养等技术, 从湖北黄陂某养殖场患病大口黑鲈(Micropterus salmoides)体内发现并分离到一株蛙病毒。患病大口黑鲈的临床症状主要表现为体表出血、溃疡, 肝脏发白。将病鱼内脏组织匀浆超微滤液接种鳜脑细胞系(mandarin fish brain, MFB)细胞能产生典型细胞病变效应(cytopathic effect, CPE), 病毒滴度达到 108.36±0.15 TCID50/mL。细胞培养病毒的超薄切片电镜观察结果显示, 细胞质中存在大量直径约为 150 nm 左右的正六边形病毒粒子, 呈晶格排列。细胞培养病毒的人工感染大口黑鲈试验结果显示, 7 d 内试验鱼死亡率高达 100%, 其临床症状与自然发病鱼相似。采用大口黑鲈病毒(largemouth bass virus, LMBV)的特异性 PCR 检测方法对患病鲈组织样品和细胞培养病毒样品进行检测, 均能扩增出 241 bp 的单一目的条带。进一步根据 GenBank 中 LMBV 主衣壳蛋白(major capsid protein, MCP)基因序列设计特异性引物, 均能从上述样品中扩增出 1392 bp 的 MCP 基因开放阅读框(open reading frame, ORF)全长。将 MCP 氨基酸全序列进行比对, 结果显示其与 Santee-Cooper 蛙病毒、孔雀鱼病毒 6 型及大口黑鲈溃疡综合征病毒的 MCP 氨基酸序列同源性高达 100%。系统进化结果显示, 与感染鱼类的虹彩病毒科蛙病毒属病毒, 如鳜鱼蛙病毒、Santee-Cooper 蛙病毒、孔雀鱼病毒 6 型和大口黑鲈溃疡综合征病毒等聚成一支。这些结果证明, 该分离株为虹彩病毒科蛙病毒属的成员, 暂命名为大口黑鲈蛙病毒(largemouth bass ranavirus, LMBRaV)湖北株 LMBRaV-HB001。病毒敏感细胞系筛选试验结果表明, 病毒 LMBRaV-HB001 感染鲤上皮瘤细胞(epithelioma papulosum cyprinid, EPC)、草鱼性腺细胞(grass carp ovary, GCO)、大鲵肌肉细胞(giant salamander muscle, GSM)和鲫脑组织细胞(gibel carp brain, GiCB)均能产生典型 CPE, 病毒滴度可达 108.0 TCID50/mL 以上。本研究首次在湖北省养殖大口黑鲈体内分离与鉴定了 LMBRaV 病毒, 建立了病毒的细胞培养方法, 为进一步研究该病毒的传播、诊断和防控技术提供了重要参考。  相似文献   

20.
Abstract. Bacterial agglutination, passive haemagglutination, complement-dependent passive haemolysis, indirect immunofluorescence, agar gel immunodiffusion and agglutination with fractions of immunized fish serum were compared for detecting humoral antibody to the lipopolysacchande (LPS) of Edwardsiella icialuri Hawke in channel catfish. Bacterial agglutination titres averaged 1: 672; passive haemagglutination titres averaged 1: 1152; and complement-dependent haemolysis titres averaged 1: 2360. Serum from non-vaccinated fish ranged from 0 to 1:32. Indirect fluorescence and immunodiffusion demonstrated positive reactions to the LPS antibody. Fractionation of immune sera produced three fractions, one of which strongly haemagglutinated E. ictaluri but the other two did not. All six serological techniques were sensitive to E. ictaluri LPS antibody.  相似文献   

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