Common Carp Production Research Articles

The rank of intensification factors strength in intensive pond production of common carp (Cyprinus carpio L.)

Intensive common carp (Cyprinus carpio L.) pond production offers an alternative to traditionally practiced extensive and semi-intensive farming technologies. Global warming increases the scarcity of water available for aquaculture, requiring increased productivity per unit of used water. The present trial was conducted on intensive rearing of two-summer-old common carp (0.5 ± 0.1) kg. Fractional factorial design (24–1, resolution IV) was applied to identify how production performance is affected by the following four factors and their interactions: I) feeding rate: ad libitum (4%) vs. restricted (2%); II) stocking density: low (1.1 t/ha) vs. high (2.2 t/ha); III) aeration rate: low (11 kW/ha) vs. high (25 kW/ha); and IV) presence or absence of co-cultured species: monoculture vs. polyculture with pikeperch (Sander lucioperca L.) reared in cages. The feeding rate appeared to be the most influential factor in growth, meat quality, water quality, and stress parameters. Although the higher stocking density might be economically justified in the short term, due to impaired welfare it brings risks in the long run. The higher rate of artificial aeration showed a negative effect on meat and water quality; however, its cooling effect might be helpful in tackling issues with extreme water temperature. The test showed feasible cage production of pikeperch even in intensive pond production. The recommended goals for feasible intensification of common carp pond aquaculture are feeding regimes aiming at better feed utilization instead of growth maximization, stocking densities up to the limits of fish welfare (gross yield <11 t/ha), optimized paddle wheel aeration in favor of algae development (<11 kW/ha), and species/technology diversification.

Partial replacement of pelleted feed by moist fermented feed improved the feed conversion efficiency, liver and intestine health, and gut microbiota structure in common carp (Cyprinus carpio)

This study aimed to explore whether the substitution of basic pellet feed by different proportions of moist fermented pellet feed affect the growth performance, liver and gut health, and intestinal microbiota structure of common carp (Cyprinus carpio). The experiment was divided into 5 groups: the control group was fed with the basic pellet feed, and the treatment groups were fed with the feed that moist fermented pelleted feed (MFF) substituted 5% (MFF5), 10% (MFF10), 15% (MFF15) and 20% (MFF20) of the basic pellet feed. Feeding trial was lasted 8 weeks. The results showed that the feed efficiency of MFF10 groups was significantly higher than that of control group. MFF replacement had no significant effect on the weight again and survival rate of C. carpio compared with Control. In addition, MFF substitution showed that the liver anti-inflammatory factors TGF-β in MFF groups except MFF5 group showed a significant upward trend, liver IL-10 of MFF15 and MFF20 groups and intestinal TNF-α of MFF10 were significantly higher than those of control group. Moreover, the intestinal zo-1 of MFF5 and MFF10 groups, hepcidin of MFF5, and defensin in MFF5 and MFF10 were significantly elevated compared with the control (P < 0.05). We also found that the abundance of Fusobacteria in the MFF10 group and Firmicutes in MFF15 increased significantly compared with the control (P < 0.05), while the abundance of Bacteroidota in MFF10 was remarkably lower than that of MFF5 and MFF15 groups (P < 0.05). Meanwhile, Chao1 and Shannon indexes in MFF15 and Ace index in MFF20 were significantly higher than those of the control (P < 0.05). These result suggested that replacement of basic pellet feed with a range of 5–15% of fermented feed could be considered as an important way to improve the health and production of common carp.

Salinity induced changes in growth and gill structure of freshwater carp, Cyprinus carpio Linn.

Aim: The present study was carried out to evaluate salinity induced changes in the growth and gill structure of cosmopolitan freshwater carp, Cyprinus carpio (Linn.). Methodology: Inland saline water (15 ‰ or g l-1) was collected from the salt affected waterlogged areas of village Shajrana (30.3346 0N, 74.1196 0E) in District Fazilka, Punjab (India) and diluted with underground freshwater for preparing different salinity levels (2 to 10 ‰). Fingerlings (10 ±2 cm) of C. carpio were exposed to 0 (control), 2, 4, 6, 8 and 10 ‰ salinity after gradual acclimatization with salinity increase @ 1 ‰ hr-1. Results: At the end of 120 days of rearing under saline conditions, 100% fish survival was observed up to 6 ‰ salinity, while 86.66 and 70.00% survival was recorded in 8 and 10 ‰, respectively. However, fish growth declined significantly at all salinity levels (p≤0.05). Gill structure was also affected at all salinity level, but pronounced changes were observed at salinity levels ≥ 6 ‰, including lamellar oedema, epithelial lifting, lamellar hyperplasia, hypertrophy, lamellar fusion, hyalinisation, aneurysm, blood congestion, etc. Interpretation: The results offer referral database to explore optimised economic production of common carp in inland saline areas of the region at salinity levels below 6 ‰. Key words: Carp, Gills, Growth, Production, Salinity, Survival

Effects of adding Moringa oleifera seeds on the performance and production of common carp (Cyprinus carpio L.)

The objective of this study was to assess the effects of utilizing Moringa oleifera at various inclusion levels in fish meal-based diets for common carp fish. In this study, we employed seeds at various concentrations, such as 2% Moringa oleifera seeds (MOS) for T2, 4% MOS for T3, and 6% MOS for T4, in comparison to control treatment T1 without it (0% MOS). The treatment T4 substantially (P&gt; 0.05) reached the highest specific growth rate, which was recorded at (0.781%), before dropping to records of (0.689%, 0.610%, and 0.229%) for treatments T3, T2, and the control group T1. Additionally, Treatment (T4) had the highest relative growth rate (13.25%), which then decreased to records of (11.21%, 9.567%, and 3.033%) for Treatments (T3), T2, and Control Treatment (T1), respectively. The treatment T4 reached the maximum value of the daily growth rate, which was recorded at (0.283%), before dropping to records of (0.238), (0.2203), and (0.063%) for the treatments T3, T2, and the control treatmentT1, respectively. Treatment (T4) had the highest reported value of the ultimate body weight, coming in at 49.44g. After then, it started to fall, and records of 45.49g for Treatments (T3), 42.43g for Treatments (T2), and 30.51g for Control Treatment were made (T1). The total recorded feed intake for treatment (T4) was 7.54g, which was the highest value. Following that, it began to decrease, and measurements of 7.07g for Treatments (T3), 6.77g for Treatments (T2), and 5.83g for Control Treatment were made (T1). The body gained weight to its highest ever recorded level of 92.74g as a result of treatment (T4). It then began to decline, with records of 78.43g for Treatments (T3), 66.96g for Treatments (T2), and 22.21g for Control Treatment (T1). Significantly, Treatment (T4) contributed to the feed conversion ratio increasing to 3.16%, the highest level ever recorded. After that, it started to go down, with records of 2.83% for Treatments (T3), 2.51% for Treatments (T2), and 0.92% for Control Treatment (T1). Contrarily, partly as a result of the Control Treatment, the Feed Efficiency Ratio improved to 1.09%, the highest level ever recorded (T1). After that, it began to decline, with records of 0.39 percent for Treatments (T2), 0.35 percent for Treatments (T3), and 0.32 percent for Treatment (T4). The effect of the treatment caused the Protein Efficiency Ratio to rise sharply to its highest recorded value of 0.81%. (T4). After then, it started to fall, with records for Treatments (T3) of 0.68 percent, Treatments (T2) of 0.59 percent, and Control Treatment of 0.19 percent (T1). The greatest level of Protein Productive Value was likewise attained by Treatment (T4), which was 3.65%; thereafter, Treatments (T3), T2, and Control Treatment (T1) each achieved records of 3.32%, 2.98%, and 3.33 %. The maximum Fat Efficiency Ratio was attained by Treatment (T3) (10.49%), but it thereafter dropped to records for Treatments (T4), (T2), and Control Treatment (T1) of 8.43%, 7.75%, and 1.70%, respectively. The aim of this study is for the purpose of providing healthy nutrition requirements for fish. It concludes that T4 treatment which contains 6% moringa seeds was the best ratio to obtain best growth performance for common carp.

Effects of demand-feeding and dietary protein level on nitrogen metabolism and symbiont dinitrogen gas production of common carp (Cyprinus carpio, L.).

Ammonia accumulation is a major challenge in intensive aquaculture, where fish are fed protein-rich diets in large rations, resulting in increased ammonia production when amino acids are metabolized as energy source. Ammonia is primarily excreted via the gills, which have been found to harbor nitrogen-cycle bacteria that convert ammonia into dinitrogen gas (N2) and therefore present a potential in situ detoxifying mechanism. Here, we determined the impact of feeding strategies (demand-feeding and batch-feeding) with two dietary protein levels on growth, nitrogen excretion, and nitrogen metabolism in common carp (Cyprinus carpio, L.) in a 3-week feeding experiment. Demand-fed fish exhibited significantly higher growth rates, though with lower feed efficiency. When corrected for feed intake, nitrogen excretion was not impacted by feeding strategy or dietary protein, but demand-fed fish had significantly more nitrogen unaccounted for in the nitrogen balance and less retained nitrogen. N2 production of individual fish was measured in all experimental groups, and production rates were in the same order of magnitude as the amount of nitrogen unaccounted for, thus potentially explaining the missing nitrogen in the balance. N2 production by carp was also observed when groups of fish were kept in metabolic chambers. Demand feeding furthermore caused a significant increase in hepatic glutamate dehydrogenase activities, indicating elevated ammonia production. However, branchial ammonia transporter expression levels in these animals were stable or decreased. Together, our results suggest that feeding strategy impacts fish growth and nitrogen metabolism, and that conversion of ammonia to N2 by nitrogen cycle bacteria in the gills may explain the unaccounted nitrogen in the balance.

The use of superior common carp for a better aquaculture

Fish farming is an economic business activity that has been carried out for a long time in Indonesia. One of the most popular commodities cultured is common carp. In 2001, common carp production was 418,910 MT, equivalent to 63.5% of Indonesia’s national production. However, the existence of obstacles in common carp culture, especially the outbreak of KHV in 2002 and the decrease of the genetic quality of fish, indicated by the slower growth of fish, resulted in a significant decrease in common carp production. The use of lower genetic quality fish causes the efficiency of the feed used is getting lower, as indicated by the high value of the FCR. In-efficient use of feed has an impact on increasing feed waste in the cultural environment. To increase common carp production, several varieties of superior common carp have been released for the farmer. Empirically, superior fish carp have a better growth rate and are more efficient in the use of feed. Culture of these superior varieties impacted to increase in the national production of common carp, by an average of 8.7%/year. On the other hand, the culture environment is kept clean due to up to 47.0±4.8% reduction in waste.

Study on the Stocking Density of Fry for Fingerling Production of Common Carp at BAPARD Nursery Ponds

Study on the Stocking Density of Fry for Fingerling Production of Common Carp at BAPARD Nursery Ponds

Impact of climate-driven temperature increase on inland aquaculture: Application to land-based production of common carp (Cyprinus carpio L.).

Climate change will expose the food-producing sector to a range of challenges. Inland aquaculture farms are particularly vulnerable, due to the difficulty in changing their location, and therefore require specific tools to predict the influence of direct and indirect effects on production, environment and economic feasibility. The objective of our study was to apply a simple set of models to produce a set of growth, risk and suitability maps for stakeholders within the common carp sector in Poland, to assist decision-making under two different scenarios of climate change: a moderate situation (RCP 4.5) and an extreme situation (RCP 8.5). We used present (2000-2019) and future projections (2080-2099) for water surface temperature based on land surface temperature data from regionally downscaled climate models to draw maps to: (i) show optimal temperature conditions for carp growth, (ii) assess risk of disease outbreak caused by three important common carp pathogens: Cyprinid herpesvirus 3 (CyHV-3), carp oedema virus (CEV) and spring viremia of carp (SVCV) and (iii) predict potential suitability changes of carp farming in Poland. The study identified areas with the most and least favourable temperature conditions for carp growth, as well as those areas with the highest/lowest number of days with suitable temperatures for virus infection. These suitability maps showed the combined effect of direct and indirect effects of climate change projections under RCP 8.5 and RCP 4.5 scenarios. The approach applied herein will be of use worldwide for analysing the risks of temperature increase to land-based aquaculture, and the results presented are important for carp farmers in Poland and elsewhere, industry in general, and government stakeholders, to understand the direct and indirect effects of climate change on the triple bottom line of people, planet, and profit.

Negative effects of undesirable fish on common carp production and overall structure and functioning of fishpond ecosystems

Planktivorous undesirable fish may threaten both fishpond ecosystem functioning and common carp ( Cyprinus carpio ) farming. The present study revealed a mechanistic understanding of the adverse ecosystem and production impacts that topmouth gudgeon ( Pseudorasbora parva ), an invasive omnivorous fish species from Asia, could represent for eutrophic fishponds in South Bohemia (Czechia). In an outdoor experiment conducted under natural conditions, six similar ponds of small size (ca. 1 ha) were similarly stocked with the same size-class common carps (1+ year-old age cohort). Three ponds were additionally stocked with heterogenous size-class of topmouth gudgeon, other three were control ponds (stocked solely with common carp). Our sampling covered one vegetation season from March to September 2020. Environmental parameters, fish and zooplankton assemblage were sampled monthly, while zoobenthos bimonthly (in April, June and August). To assess the potential effect of overall fish predation and its change during the season, we calculated a fish stock index combining fish density and biomass at the time, referred as FSI C for stocked fish (common carp) and FSI U for undesirable fish (topmouth gudgeon). Some tenfold increase in FSI U reflected an overall effect of topmouth gudgeon predation. Significantly ( p < 0.05) lower FSI C indeed indicated the adverse effect of topmouth gudgeon on the carp populations compared to the control ponds since August. Our results clearly showed a significant top-down effect of topmouth gudgeon on planktonic crustaceans, especially large Daphnia spp. and other cladoceran species. The complete elimination of cladocerans in the second half of the growing season probably contributed to impaired growth of carp and increased consumption of zoobenthos observed in the undesirable fishponds. Our study suggested indeed that water transparency, often used as a simple indicator of water quality in fishponds, did not correspond well with the ecological status, not even biodiversity, of the fishponds under study. The voracious undesirable fish overexploited zooplankton and significantly out-competed commercially reared common carp, which then switched more to foraging on zoobenthos. Thus, efficient eradicating undesirable fish seems to be a superior tool for overall restoring the eutrophic fishpond ecosystems and improving their ecological status. • Voracious undesirable fish cause a threat to carp production and fishpond ecosystem. • Planktivorous fish out-compete carp, which then switch to foraging on zoobenthos. • Eradicating undesirable fish is a superior tool for restoring eutrophic fishponds.

Correlation of planktonic biomass with other physico-chemical parameters of water quality in fertilized fish ponds

The production of common carp (Cyprinus carpio) was studied in pond fertilized with cow-dung @ 0.1g N/10g in the presence of planktonic biomass. The correlation of planktonic biomass with water quality physicochemical parameters of three fish ponds, was studied. The parameters such as pH, temperature, dissolved oxygen, total alkalinity, total dissolved solids, total hardness, magnesium, calcium, light penetration, total solids, carbonates and bicarbonates, were analyzed in a laboratory using standard protocols. Data collected at the end of the present experimental study was subjected to an appropriate statistical analysis to appraise the correlation coefficients of planktonic biomass with several physicochemical parameters of three ponds under study. In most cases significant correlations were recorded between biomass and key physico-chemical attributes of the ponds.

Genetic Investigation of Aral Wild Common Carp Populations (Cyprinus carpio) Using ddRAD Sequencing

Common carp (Cyprinus carpio) is a widespread freshwater fish species of the Cyprinidae family, one of the largest and most diverse fish families. The natural habitats of C. carpio extend from Western Europe to South-East Asia. Common carp has remained an economically important fish species in aquaculture for many centuries and its production nowadays exceeds 4 million tons worldwide and continues to grow. The taxonomy of C. carpio is complicated, since this species is usually distinguished in two, three, and even four distinct subspecies. In the present study, we used ddRAD-sequencing to genotype 30 specimens from five wild common carp populations from the Ponto-Caspian, Balkhash-Ile, and Aral Sea geographical regions. It is demonstrated that they differ at the population level according to F-statistics analysis. At the same time, the subspecies status of C. carpio aralensis has not yet been confirmed. We found several loci that can be used as a discriminant for Aral and Ponto-Caspian wild common carp populations. It is suggested that Aral carp (C. carpio aralensis), which inhabits Balkhash-Ile and Aral Sea basins, is related to Ponto-Caspian or European carp (C. carpio carpio). Moreover, Aral carp might be the ancestor for European carp subspecies. Our results can be used to develop population-specific, high-density SNP marker panels, allowing the trade control of common carp production in the Eurasian Economic Union.

Отримання та вирощування мальків великоротого окуня (Micropterus salmoides (Lacеpеde, 1802)) в умовах тепловодних ставових рибних господарств (огляд)

Purpose. Largemouth bass (Micropterus salmoides), a fish species native to freshwaters of North America, is a promising object of aquaculture all over the world. This is evidenced by the fact that this species is currently actively cultivated in aquaculture of more than 50 countries worldwide, on all continents, with the exception of Antarctica and Australia, both for recreational fishing and as a table fish. If we consider the history of breeding and cultivation of the largemouth bass, we can note a tendency to a continuous expansion of the stages of cultivation and transition from polyculture to monoculture. For example, in the first half of the last century, fish farms in the United States raised mainly juveniles of largemouth bass for stocking to natural water bodies, but currently most farms use the full production cycle from fry to marketable fish. In addition, earlier largemouth bass was used in many countries mainly as an additional object of aquaculture (biomeliorator) to increase the production of common carp, but now, thanks to the development of recreational fishing, it is increasingly becoming the main object of aquaculture, which is facilitated by the intensification of cultivation methods. Nowadays, there are many methods of growing largemouth bass, from the simplest, extensive, when fish are raised on natural food supply, to most intensive using flow-through aquaculture systems and off-season spawning. On the territory of Ukraine, it may be effective to use pond aquaculture of largemouth bass, which begins from the production of larvae and fry at fish farms. This stage of fish farming will be discussed in this article. Findings. This article contains brief information on method of natural spawning of largemouth bass, filling ponds with water, selection of broodstock and norms for their stocking to spawning ponds, spawning behavior of fish, peculiarities of caring for larvae and fry, sorting juveniles, as well as minimizing injuries during manipulations with fish. Practical value. Information from this review can be used for development of a new method for production of largemouth bass larvae and fry at warm-water pond farms in Ukraine, taking into account climatic conditions and local specificities of aquaculture. Key words: Largemouth bass, Micropterus salmoides, recreation fishing, sport fishing, pond fish farm, aquaculture, biomeliorator, larvae, fry, polyculture, monoculture, intensification, perspective species.

Evaluation of different types of feed in carp polyculture

An experiment was conducted to assess the effects of different types of feed on the growth and production of common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella), and rohu (Labeo rohita) for 6 months in 9 ponds of 150 m2 each. They were fed on mash feed (T1), sinking pellet (T2), and floating pellet (T3) @ 5% of total body weight daily along with finely chopped Dubo grass (Cynodon dactylon) for grass carp. Combined extrapolated gross and net fish yield was found the highest in T3, intermediate in T2, and lowest in T1. The feed conversion ratio was found the least in T3 followed by T2 and T1. Total production costs involved in fish production were found the highest in T3 followed by T2 and T1. The gross margin was significantly higher in T2 and T3 than in T1 (p

Genetic Diversity and Structure of Common Carp (Cyprinus carpio L.) in the Centre of Carpathian Basin: Implications for Conservation

Hungary is one of the largest common carp-production countries in Europe and now, there is a large number of local breeds and strains in the country. For proper maintenance of the animal genetic resources, information on their genetic diversity and structure is essential. At present, few data are available on the genetic purity and variability of the Hungarian common carp. In this study, we genetically analyzed 13 strains in Hungary and, in addition, the Amur wild carp, using 12 microsatellite markers. A total of 117 unique alleles were detected in 630 individuals. Low levels of genetic differentiation (Fst and Cavalli–Sforza and Edwards distance) were estimated among strains. The AMOVA showed the low but significant level of genetic differentiation among strains (3.79%). Bayesian clustering analysis using STRUCTURE classified the strains into 14 different clusters. The assignment test showed that 93.64% of the individuals could be assigned correctly into their original strain. Overall, our findings can be contributed to complementing scientific knowledge for conservation and management of threatened strains of common carp.

Nutrient footprint and ecosystem services of carp production in European fishponds in contrast to EU crop and livestock sectors

There have been some arguments concerning supplementary feed (cereals) based common carp production in fishponds and water pollution, mostly in Central Europe. Using Czech Republic (top producer in EU) as a benchmark and combining data on nutrient digestibility of feedstuffs used combined with analyses of literature data, we have assessed – nutrient footprint (∼9.4–10.8 kg N ha−1, ∼2.7–3.2 kg P ha−1; 1.5–4 × < EU crop-livestock sectors); nutrient utilization efficiencies (NUEN ∼36%, NUEP ∼50%; 1.5–1.7 × > EU livestock average); autochthonous nutrient removal (∼8–9.2 kg N ha−1, 1.4–1.6 kg P ha−1); eco-cost burden (13–29 × ≪ positive services); eco-services (∼74.5–100.6 million € country−1; ∼2375 € ha−1) of carp production in Central Eastern European Region (CEER). Digestible nutrients offered by natural prey (7.9% N, 1% P on dry matter basis) to carp are ∼5–8 times higher than those provided by cereals and remains the key determinant for production. Despite this, 70–90% of nutrient footprint from feeding is contributed by cereals. Neutral footprint (∼374 kg ha−1) and exclusively natural (up to 300 kg ha−1) carp production intensities were identified, following which, commercial interest of carp farming may falter (costing intangible losses >56.5 million € in CEER), despite achieving ‘greener-goals’. Per production cycle, carp aquaculture in CEER fishponds offer at least 579 million € worth of services. Our results show that carp production in ponds have lesser nutrient burden than crop and livestock productions in EU. Existing management of fishponds ‘barely meet’ optimum P requirements of common carp and present production intensity should not be vilified as a pollution causing activity. Risks and solutions for achieving both environmental (minimized footprint) and aquaculture goals (uncompromised production) are discussed.

Comparision of growth of mature all-female and mixed-sex Common carp (Cyprinus carpio L.) stocks in RAS

The common carp (Cyprinus carpio L.) is the most important fish species in Hungary, it is more than 70% of the total Hungarian fish production. The common carp production is important not only just in Hungary but in Middle-East Europe, as well as Southeast Asia. Majority of the production comes from fishpond culture. If the production sector wants to meet the increasing customer demands, there is need to intensify research on the intensive fish production opportunities for example all-female common carp technologies. The all-female technology is one of a genom-manipulation technology. Its production showed better growth rate than mixed-sex population in pond culture. Our experiment combined the recirculation aquaculture system (RAS) and the all-female common carp stocks intensification technologies. The reason for the experiment, is that there are no result about the growth of all-female common carp growth in RAS. &#x0D; The experiment used the „Tatai grey scale type” common carp stocks. We propagated two all-female stocks (T2 and T3) and a control group (TK). Due to technological characteristics of RAS, the water quality parameters were the same for all treatments and corresponded to the technological tolerance of common carp.&#x0D; The experimental period was from July 10, 2019 – November 20, 2019. Result of growth performance showed that the growth of mixed-sex stock was significantly higher than all-female stocks; (Control=3692.0±590.5g, T2=3438.8±415.4g, T3=3294.1±659.1g). Feed conversation ratio (Control=1.3±0.1 T2=1.5±0.2 T3=1.6±0.5) and SGR% (Control=0.8±0.0 T2=0.7±0.1 T3=0.7±0.1) were similar. &#x0D; By the results it can be said the all-female common carp technology has neither advantages nor disadvantages compared to the mixed-sex stock. The all-female technology can be beneficial if the consumers need female common carps. It is worth continuing the experiment and examine how the stocks will perform above 3kg body weight.

Breeding and fingerling production of common carp (Cyprinus carpio) in coldwater region with water optimization

Breeding and fingerling production of common carp (Cyprinus carpio) in coldwater region with water optimization

Different transcriptional response between susceptible and resistant common carp (Cyprinus carpio) fish hints on the mechanism of CyHV-3 disease resistance

BackgroundInfectious disease outbreaks form major setbacks to aquaculture production and to further development of this important sector. Cyprinid herpes virus-3 (CyHV-3) is a dsDNA virus widely hampering production of common carp (Cyprinus carpio), one of the most farmed fish species worldwide. Genetically disease resistant strains are highly sought after as a sustainable solution to this problem. To study the genetic basis and cellular pathways underlying disease resistance, RNA-Seq was used to characterize transcriptional responses of susceptible and resistant fish at day 4 after CyHV-3 infection.ResultsIn susceptible fish, over four times more differentially expressed genes were up-regulated between day 0 and 4 compared to resistant fish. Susceptible and resistant fish responded distinctively to infection as only 55 (9%) of the up-regulated genes were shared by these two fish types. Susceptible fish elicited a typical anti-viral response, involving interferon and interferon responsive genes, earlier than resistant fish did. Furthermore, chemokine profiles indicated that the two fish types elicited different cellular immunity responses. A comparative phylogenetic approach assisted in chemokine copies annotation pointing to different orthologous copies common to bony-fishes and even carp-specific paralogs that were differentially regulated and contributed to the different response of these two fish types. Susceptible fish up-regulated more ccl19 chemokines, which attract T-cells and macrophages, the anti-viral role of which is established, whereas resistant fish up-regulated more cxcl8/il8 chemokines, which attract neutrophils, the antiviral role of which is unfamiliar.ConclusionsTaken together, by pointing out transcriptional differences between susceptible and resistant fish in response to CyHV-3 infection, this study unraveled possible genes and pathways that take part in disease resistance mechanisms in fish and thus, enhances our understanding of fish immunogenetics and supports the development of sustainable and safe aquaculture.

Carbon nanotube-based DNA vaccine against koi herpesvirus given by intramuscular injection

Koi herpesvirus (KHV) also named Cyprinid Herpesvirus 3 (CyHV-3) is one of the most threatening pathogens affecting common carp production as well as the valued ornamental koi carp. The current commercial vaccines available are costly and potentially cause severe stress caused by live virus. KHV ORF149 gene has been proved encoding one of the main immunogenic proteins for KHV. In this study, we coupled a plasmid expression vector for ORF149 to single walled carbon nanotubes (SWCNTs) for an anti-KHV vaccine. The vaccine conferred an 81.9% protection against intraperitoneal challenge with KHV. Importantly, SWCNTs as a promising vehicle can enhanced the protective effects 33.9% over that of the naked DNA vaccine at the same dose. The protection was longer and serum antibody production, enzyme activities and immune-related gene expression were all induced in fish vaccinated with the nanotube-DNA vaccine compared with the DNA alone. Thereby, this study demonstrates that the ORF149 DNA vaccine loaded onto SWCNTs as a novel vaccine might provide an effective method of coping with KHV disease using intra-muscular vaccination.

Current knowledge and future prospects of vaccines against cyprinid herpesvirus 3 (CyHV-3)

Aquaculture is one of the world's most important and fastest growing food production sectors, with an average annual growth of 5.8% during the period 2001–2016. Common carp (Cyprinus carpio) is one of the main aquatic species produced for human consumption and is the world's third most produced finfish. Koi carp, on the other hand, are grown as a popular ornamental fish. In the late 1990s, both of these sectors were threatened by the emergence of a deadly disease caused by cyprinid herpesvirus 3 (CyHV-3; initially called koi herpesvirus or KHV). Since then, several research groups have focused their work on developing methods to fight this disease. Despite increasing knowledge about the pathobiology of this virus, there are currently no efficient and cost-effective therapeutic methods available to fight this disease. Facing the lack of efficient treatments, safe and efficacious prophylactic methods such as the use of vaccines represent the most promising approach to the control of this virus. The common carp production sector is not a heavily industrialized production sector and the fish produced have low individual value. Therefore, development of vaccine methods adapted to mass vaccination are more suitable. Multiple vaccine candidates against CyHV-3 have been developed and studied, including DNA, bacterial vector, inactivated, conventional attenuated and recombinant attenuated vaccines. However, there is currently only one vaccine commercially available in limited regions. The present review aims to summarize and evaluate the knowledge acquired from the study of these vaccines against CyHV-3 and provide discussion on future prospects.