Goldfish Research Articles

Unveiling potential sex-determining genes and sex-specific markers in autotetraploid Carassius auratus.

Autotetraploid Carassius auratus is a stable hereditary autotetraploid fish resulting from the hybridization of Carassius auratus red var. (RCC, ♀) × Megalobrama amblycephala (BSB, ♂), containing four sets of RCC chromosomes. However, the molecular mechanism underlying the determination of sex in this species remains largely unknown. Currently, there lacks a full understanding of the molecular mechanisms governing sex determination and specific molecular markers to differentiate sex in this species. In this study, 25,801,677 SNPs (Single-nucleotide polymorphism) and 6,210,306 Indels (insertion-deletion) were obtained from whole-genome resequencing of 100 individuals (including 50 female and 50 male). Further identification confirmed the candidate chromosomes as Chr46B, with the sex-determining region located at Chr46B: 22,500,000-22,800,000 bp. Based on the male-specific insertion (26 bp) within the candidate sex-determining region, a pair of sex-specific molecular markers has been identified. In addition, based on the screening of candidate sex-determining region genes and RT-qPCR validation analysis, ADAM10, AQP9 and tc1a were identified as candidate sex-determining genes. These findings provide a robust foundation for investigating sex determination mechanisms in fish, the evolution of sex chromosomes, and the development of monosex populations.

Effects of three different protein levels on the growth, gonad development, and physiological biochemistry of female Pengze crucian carp (Carassius auratus var. Pengze) broodstock

A 56-days feeding experiment was conducted to evaluate the effect of dietary protein levels on fish growth, gonad development, and physiological biochemistry of female Pengze crucian carp (Carassius auratus var. Pengze) broodstock. Three isoenergetic diets were formulated, and the crude protein levels were 26.85%, 35.73% and 44.38%, the lipid levels were 7.39%, 7.92% and 7.91%, respectively. The results showed that the weight gain rate (WGR), the specific growth rate (SGR) and the protein efficiency ratio (PER) of the female Pengze crucian carp broodstock increased significantly and the feed conversion ratio (FCR) decreased significantly when the dietary protein level was 35.73% (P < 0.05). The WGR, the SGR and the PER were significantly higher in the 35.73% and 44.38% protein groups than in the 26.85% protein group (P<0.05). Increasing dietary protein levels led to a significant increase in the gonad index and the egg menstrual length of the female Pengze crucian carp broodstock (P<0.05). The higher protein levels resulted in a significant increase in total amino acids, total essential amino acids, and total nonessential amino acids (P<0.05). The varying ovaries of each group of total saturated fatty acids, total highly unsaturated fatty acids, and total polyunsaturated fatty acids all increased significantly with increasing protein levels (P<0.05). Furthermore, the aspartate transaminase (AST), low-density lipoprotein cholesterol (LDLC), and malondialdehyde (MDA) contents in plasma were significantly lower in the 35.73% and 44.38% groups than in the 26.85% group (P < 0.05). The 35.73% group exhibited the highest plasma superoxide dismutase (SOD) activity,. The plasma vitellogenin (VTG), estradiol 2 (E2), and progesterone (PROG) in plasma of female Pengze crucian carp broodstock were significantly higher in the 35.73% and 44.38% protein groups than in the 26.85% protein group (P<0.05). The results showed that the addition of an appropriate amount of protein to the feed can significantly improve the growth, gonadal development, and health of female Pengze crucian carp. In this study, the effect of 35.73% protein concentration was better than in the other two groups.

Study of Some Environmental and Reproductive Aspects of Some Fish Species in the Tigris River West of the City of Samarra, Salah Al-Din / Iraq

The study was conducted on the Tigris River in the Qalaa area, west of the city of Samarra, Salah al-Din/Iraq, for the period between October 2023 and March 2024, 117 fish were caught, with one catch per month. It has been observed that the higher sex ratio tends to favor females in Carasobarbus luteus, Luciobarbus xanthopterus, Carassius auratus, Leuciscus vorax, and Cyprinus carpio with ratios of 7.0:1, 5.0:1, 4.6:1, 3.5:1 and 3.0:1 respectively, while the lower percentage tends to favor females in Acantho brama marmid, C. macrostomum and Chondrostoma regium in the ratio of 1.8:1, 1.5:1 and 1.19:1, respectively. show the monthly changes in gonad (G.S.I) function for male and female fish (Chondrostoma regium, Carassius auratus and Carasobarbus luteus), (Acantho brama marmid, Leuciscus vorax and Luciobarbus Xanthopterus) and (C. macrostomum and Cyprinus carpio) respectively. The water temperature ranged between 10 and 22°C. The highest water temperature was in October and the lowest in February. The highest value of dissolved oxygen was 8.4 mg/L in March and the lowest value of dissolved oxygen was 6.5 mg/L in October. The highest turbidity value was 49 NTU 1 in December, and the lowest value 39.5 NTU was recorded in February.

Cardiac regeneration in goldfish (Carassius auratus) associated with increased expression of key extracellular matrix molecules.

Cardiac regeneration is a natural phenomenon that occurs in many species outside of humans. The goldfish (Carassius auratus) is an understudied model of cardiac wound response, despite its ubiquity as pets as well as its relationship to the better-studied zebrafish. In this study, we examined the response of the goldfish heart to a resection injury. We found that by 70 days post-injury, goldfish scarlessly heal cardiac wounds under a certain size, with local cardiomyocyte proliferation driving the restoration of the myocardial layer. We also found the upregulation of extracellular matrix components related to cardiac regeneration in the injury site. This upregulation correlated with the level of cardiomyocyte proliferation occurring in the injury site, indicating an association between the two that warrants further exploration.

Growth performance, mucosal immunity and disease resistance in goldfish (Carassius auratus) orally administered with Escherichia coli Strain Nissle 1917.

The current research aimed to shed light on the efficacy of Escherichia coli strain Nissle 1917 (EcN) on goldfish (……) growth, gut immunity, morphology, bacterial nutritional enzyme activity and resistance to Aeromonas hydrophila infection. Fish fed with EcN at 106, 107 and 108CFU/g feed for 80days showed an enhancement in growth better than control fish. The gut innate immunity in terms of lysozyme activity, immunoglobulin and total protein levels was increased in the treatment fish with the best result being observed in fish fed EcN at 108CFU/ g. In addition, an increase was noted in the upregulation of immune-relevant genes, namely lysozyme, interleukin-1β, inducible nitric oxide synthase and tumor necrosis factor α of fish intestine. A marked surge in the number of proteolytic and heterotrophic bacteria was noted in the gut of fish nourished with the probiotic. Histological studies exhibited an improvement in the intestinal absorption surface area, intraepithelial lymphocyte count and goblet cell density. Significantly higher survival rate was obtained in fish fed EcN at 108CFU/g compared with the fish fed with the basal diet. These data exhibited the beneficial effect of EcN on goldfish growth, digestive enzymes, intestine heterotrophic bacteria and resistance against Aeromonas hydrophila challenge. This study confirmed the favorable outcomes resulting from the administration of EcN at108 CFU/g.

Potential effects of host competence and schooling behavior on parasite transmission in a host-pathogen system: a test of the dilution effect

High species diversity in a community may reduce the risk of infectious disease, termed the dilution effect. However, the generality of the dilution effect in different disease systems remains controversial as both host competence and behaviors of hosts may play roles in dilution or amplification of disease. Using the goldfish (Carassius auratus)-monogenean ectoparasite (Gyrodactylus kobayashii) system, effects of host competence and schooling behavior on parasite transmission were investigated while holding focal host density constant. Following competency tests of 12 fish species as potential hosts for the parasite, infection by G. kobayashii was determined on fins of goldfish mixed with each of three different species based on their level of host competence, including Prussian carp, Carassius gibelio (low competence), grass carp, Ctenopharyngodon idellus (non-competent), swordtail, Xiphophorus helleri (non-competent), and the four species combined. Compared with mean abundance (85.8 ± 25.1) on goldfish in the control group, the mean abundance on goldfish decreased significantly when paired with 10 Prussian carp (30.0 ± 16.5), but did not differ significantly when paired with 10 swordtail (70.0 ± 22.2), 10 grass carp (116.1 ± 33.2), or the multi-species of three Prussian carp, four grass carp and three swordtail (75.9 ± 30.8) during the 11-day experiment. The parasite was also found on the Prussian carp in the Prussian carp group and the multi-species group at a mean abundance of 7.1 and 10.9, respectively. Video recording showed that the school of goldfish mixed well with the Prussian carp, while they maintained separation from the grass carp and swordtail when mixed together. The distance between goldfish increased, and swimming speed and contact time decreased with the additional of other fish species for all groups. The results suggested that the presence of a low-competence host in sufficient numbers was a necessary condition for a dilution effect due to encounter reduction, and the dilution effect may also be enhanced by changes in schooling behavior of goldfish in the presence of low competence hosts. However, the presence of non-competent hosts did not result in any dilution effect owing to the specialist nature of the parasites and the lack of mixing with schools of goldfish.

Exposure to neonicotinoid pesticides induces physiological disorders and affects color performance and foraging behavior in goldfish.

We investigated the effects of neonicotinoid pesticides (NEOs) on the spontaneous swimming and foraging behavior, as well as the morphological and physiological changes of goldfish. Most fish reared in thiamethoxam (THM)-sprayed rice fields showed the scales easily peeled off, and increased ascites. Some individuals showed decreased bio-defense activity and low plasma Ca2+. Similar changes were found in the exposure test to THM (1.0 and 20.0 μg/L) and dinotefuran (1.2 and 23.5 μg/L). Next, the effects of a low concentration of THM (1.0 μg/L) on the spontaneous swimming and foraging behavior of fish were examined. Fish exposed to THM for 1 week became restless and had increased the swimming performance, especially under natural light, white LED lighting and blue LED lighting. Goldfish exposed to THM had also increased intake of shiny white beads under green LED illumination. These results indicate that the exposure to NEO, even for a short period and at low levels, not only suppressed bio-defense activities and metabolic abnormalities, but also stress response, the swimming and foraging behavior of the fish are likely to be significantly suffered.

Efficacy of clove oil and rosewood oil as anesthetics on goldfish (Carassius auratus)

Anesthetics have an essential role in aquaculture operations because they minimize physical injury during various handling practices such as sampling, weighing, length measurement and tagging, which decreases stress on fish. Many fish farmers are involved in using alternative fish anesthetic agents with minimal side effects to life such as herbal essential oils. This study aims at investigating the efficacy of clove oil and rosewood oil as anesthetics on goldfish Carassius auratus. Anesthesia effect of both oils was tested in six different concentrations (i.e., 100, 150, 200, 250, 300 and 350 mg/l of water) on ten fish between 6–25 g weight and 9–14 cm length. The efficacy of both oils was assessed on the basis of the fish behavior. The induction time (min) was assessed by loss of swimming (LS), partial loss of equilibrium (PLE), final loss of equilibrium (FLE), and medullar collapse (Mc). The fish were observed for balance and response to a tactile stimulus in each treatment. Both clove oil and rosewood oil contributed well as anesthetics as they caused loss of equilibrium and swimming ability in the goldfish. In contrast, clove oil generated more rapid induction, prolonged recovery, and a narrow margin of safety. Fish farmers should use natural and environment friendly anesthetic agents instead of chemical ones, as they may alter negatively the growth and health of fish.

Effects of coated Enterococcus faecium on the growth performance, immunity, digestive enzyme activity, intestinal morphometry, and microbiota of crucian carp (Carassius auratus gibelio)

The experiment was carried out to evaluate the effects of double-layer-coated Enterococcus faecium on the growth performance, liver biochemical indices, digestive enzyme activity, intestinal morphometry, immunity gene expression, and microbiota of crucian carps (Carassius auratus gibelio). A total of 320 fish (mean weight 11.0 ± 0.04 g) were randomly distributed into 3 treatment groups of 4 replicates per treatment (20 fish/replicate). Three different experimental diets were designed: dietary C without double-layer-coated E. faecalis, dietary LP supplemented with 1.0 × 107 CFU/g, and dietary HP supplemented with 1.0 × 108 CFU/g double-layer-coated E. faecalis. The fish was fed for 70 days with different diets, followed by a challenge with lipopolysaccharide (LPS). The results showed that the weight gain and specific growth rate increased and the feed conversion rate decreased in the dietary HP (P < 0.05). The dietary LP had higher lipase and protease activities, and amylase activity increased in the dietary LP and HP after the LPS challenge (P < 0.05). The dietary HP had higher villi height (VH), thicker muscular thickness (MT), and higher VH/MT (VCR) in the intestine (P < 0.05). The intestines were damaged by the LPS challenge; the damage to the dietary HP was alleviated, showing a higher VH, thicker MT, and higher VCR (P < 0.05). The glutathione peroxidase activity of the liver was increased in the dietary HP (P < 0.05). There was no significant difference in liver antioxidant capacity with the LPS challenge among all diets. There was no significant difference in the expression level of the Occludin and Claudin-12 genes among all diets that was up-regulated in dietary HP after LPS challenge (P < 0.05). High-throughput sequencing revealed that the supplementation of double-layer-coated E. faecium increased the species diversity of the intestinal. In conclusion, double-layer-coated E. faecium can improve the absorption of nutrients, enhance immunity, maintain balance in the intestine microbiota, and promote the growth of crucian carp. The supplementation of double-layer-coated E. faecium in the diet can alleviate the intestinal damage caused by LPS challenge.

Variation and Interaction of Distinct Subgenomes Contribute to Growth Diversity in Intergeneric Hybrid Fish.

Intergeneric hybridization greatly reshapes regulatory interactions among allelic and non-allelic genes. However, their effects on growth diversity remain poorly understood in animals. In this study, we conducted whole-genome sequencing and RNA sequencing (RNA-seq) analyses in diverse hybrid varieties resulting from the intergeneric hybridization of goldfish (Carassius auratus red var.) and common carp (Cyprinus carpio). These hybrid individuals were characterized by distinct mitochondrial genomes and copy number variations. Through a weighted gene correlation network analysis, we identified 3693 genes as candidate growth-regulated genes. Among them, the expression of 3672 genes in subgenome R (originating from goldfish) displayed negative correlations with growth rate, whereas 20 genes in subgenome C (originating from common carp) exhibited positive correlations. Notably, we observed intriguing patterns in the expression of slc2a12 in subgenome C, showing opposite correlations with body weight that changed with water temperatures, suggesting differential interactions between feeding activity and weight gain in response to seasonal changes for hybrid animals. In 40.31% of alleles, we observed dominant trans-regulatory effects in the regulatory interaction between distinct alleles from subgenomes R and C. Integrating analyses of allelic-specific expression and DNA methylation data revealed that the influence of DNA methylation on both subgenomes shapes the relative contribution of allelic expression to the growth rate. These findings provide novel insights into the interaction of distinct subgenomes that underlie heterosis in growth traits and contribute to a better understanding of multiple allele traits in animals.

Microfluidic Chip Coupled with MALDI-TOF MS for Multitarget Detection of Allergens in Crucian Carp (Carassius auratus).

The goal of the present study was to establish a rapid, simple method for simultaneous allergy testing of sera from multiple fish-allergic patients. Sera from fish-allergic patients were pooled and used for capturing allergens in fish muscle of crucian carp (Carassius auratus), which was studied as a fish model. Sarcoplasmic proteins of crucian carp (Carassius auratus) were extracted for the analysis of allergens. Anti-human IgE antibody-functionalized magnetic beads were utilized to collect IgE antibodies from human pooled sera. The isolation of allergenic proteins was immunomagnetically performed in microfluidic channels, and the elution of the captured allergenic proteins was done with 5% (v/v) acetic acid aqueous solution. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and peptide mass fingerprinting were used for the analysis of tryptic digests of eluted proteins. Ten potential allergenic proteins were identified from crucian carp (Carassius auratus). The present protocol provides a rapid, efficient, and simple method for simultaneous detection of multiple allergens, based on multitargeted antibodies from pooled sera of allergic patients. The constructed multiple antibody-modified MBs can be applied for the deallergenicity of food matrices. The efficiency of allergen detection can be greatly improved, with promising application in allergen discovery and filtration for other muscle-based foods.

Inherited anoxia tolerance and growth performance can result in enhanced invasiveness in hybrid fish.

Northern hemisphere freshwater ecosystems are projected to experience significant warming and shortening of winter duration in this century. This change coupled with depletion of oxygen (hypoxia) will result in a shift toward fish species with higher optimal temperatures for growth and reproduction that can mitigate hypoxic stress. Here, we tested the assumption that reproduction between two distant species, i.e. anoxic-intolerant common carp (Cyprinus carpio) and anoxic-tolerant goldfish (Carassius auratus), results in the expression of genes responsible for ethanol synthesis (alcohol dehydrogenase and pyruvate dehydrogenase subunit E1β2). The expression of this ethanol-producing pyruvate decarboxylase pathway may transform the biochemical characteristics of progeny into anoxic-tolerant hybrids, expanding their suitable environmental range and potentially increasing invasiveness. Concurrently, a genetic strategy for improving fish tolerance to oxygen-depleted environments will be a valuable physiological trait in fish culture. Differential quantification of gene expression by analyzing mRNA revealed that, compared with koi×koi, koi female×goldfish male (F1 hybrid) possessed the pyruvate dehydrogenase subunit E1β2 gene construct, which was expressed at significantly greater levels in red muscle. The potential of this hybrid to both survive in extreme anoxic conditions and grow at elevated water temperatures would likely contribute to their ecological success.

Optimizing Goldfish (Carassius auratus) Breeding and Larval Nurturing for Materialistic Aquaculture Utilizing Synthetic Hormones

Gold fish (Carassius auratus) are familiar in India as an ornamental freshwater fish with economic importance. This experiment aimed to explore the possibility for mass-scale breeding and larval rearing of goldfish under biofloc setup. Natural brooders were collected, acclimatized and induced to breed utilizing synthetic hormones at various dosages. Breeding execution parameters namely spawning success, fertilization rate and hatching performance were analysed. The highest fertilization and hatching rate were gradually noticed at 80.8% and 80.9% by using a dose of 0.4ml/kg body weight for females and 0.2ml/kg for males. Larval rearing was accomplish by applying several live and formulated feeds across various life stages in normal rearing tanks and biofloc tanks also. The growth performance of larvae in biofloc tanks express a satisfactory rate, with a maximum weight gain of 7.1 g and length gain of 5 cm over 120 days compared to 5.1 g and 3.5 cm in normal tanks. Water quality parameters were kept within the optimum range all over the experiment. The functionable study exhibits the viability of captive breeding and mass scale larval nurturing of goldfish employing induced breeding techniques and biofloc technology.

A leukocyte immune-type receptor specific polyclonal antibody recognizes goldfish kidney leukocytes and activates the MAPK pathway in isolated goldfish kidney neutrophil-like cells

Leukocyte immune-type receptors (LITRs) belong to a large family of teleost immunoregulatory receptors that share phylogenetic and syntenic relationships with mammalian Fc receptor-like molecules (FCRLs). Recently, several putative stimulatory Carassius auratus (Ca)-LITR transcripts, including CaLITR3, have been identified in goldfish. CaLITR3 has four extracellular immunoglobulin-like (Ig-like) domains, a transmembrane domain containing a positively charged histidine residue, and a short cytoplasmic tail region. Additionally, the calitr3 transcript is highly expressed by goldfish primary kidney neutrophils (PKNs) and macrophages (PKMs). To further investigate the immunoregulatory potential of CaLITR3 in goldfish myeloid cells, we developed and characterized a CaLITR3-epitope-specific polyclonal antibody (anti-CaL3.D1 pAb). We show that the anti-CaL3.D1 pAb stains various hematopoietic cell types within the goldfish kidney, as well as in PKNs and PKMs. Moreover, cross-linking of the anti-CaL3.D1-pAb on PKN membranes induces phosphorylation of p38 and ERK1/2, critical components of the MAPK pathway involved in controlling a wide variety of innate immune effector responses such as NETosis, respiratory burst, and cytokine release. These findings support the stimulatory potential of CaLITR3 proteins as activators of fish granulocytes and pave the way for a more in-depth examination of the immunoregulatory functions of CaLITRs in goldfish myeloid cells.

Comparative study of hypoxic tolerance between the hybrids of white crucian carp (♀) × red crucian carp (♂) and its parents

The hybrid of female white crucian carp (Carassius auratus cuvieri, WCC) × male red crucian carp (Carassius auratus red var. RCC) (WR), combines desirable characteristics of both parents, including tender meat, rapid growth rate, and strong resistance. To test the hypoxia tolerance of WR, an experiment of exposure to hypoxic conditions was conducted on WR, RCC, and WCC. The results showed that WR and RCC exhibited stronger hypoxia tolerance capacity compared to WCC. The strong resistance to hypoxia of WR and RCC was manifested by the absence of damage to the hepatopancreas after hypoxia, and the fish can adapt to the hypoxic environment by enhancing the hematopoietic function of hematopoietic tissue, remodeling gill morphology, and activating the antioxidant system. By contrast, after hypoxia, the number of red blood cells and the concentration of hemoglobin in the blood of WCC decreased, and the hepatopancreas was seriously damaged, indicating that the WCC is not as tolerant to low oxygen conditions as RCC and WR.

Immersion immunization with recombinant Saccharomyces cerevisiae displaying ORF25 induced protective immunity against cyprinid herpesvirus 2.

Displaying antigens on yeast surface as an oral vaccine has been widely explored, while its potential as an immersion vaccine has not been evaluated. Here, an immersion vaccine was prepared by displaying ORF25 of Cyprinid herpesvirus 2 (CyHV-2) on the surface of Saccharomyces cerevisiae. Carassius auratus gibelio was immersion immunized by 2 × 107 CFU/mL yeast for 2 h, and reinforce the immunity using the same method 14 days after the first immunization. The results showed that ORF25 specific antibody in immunized crucian carp serum was detected at a high level, and the mRNA expression level of IgM, IgT, IL-1β, and IFN-1 in vaccinated head-kidney and spleen tissues were higher than the control group, indicating that innate and adaptive immunity were induced. Moreover, the immersion vaccination provided effective protection for fish against CyHV-2, leading to a relative percent survival of 50.2%. Meanwhile, immersion vaccination restrained virus replication and histological damage in CyHV-2 infected crucian carp. Our data suggested that immersion immunization of S. cerevisiae-displayed ORF25 could be served as a candidate vaccine to prevent CyHV-2 infection.

Effect of fermented grain cereal milling by-product on the enhancement of physiological and reproductive parameters of goldfish (Carassius auratus) broodstock

The aim of this work was to assess the effect of feeding goldfish (Carassius auratus) broodstock with diets containing dietary fermented grain cereal milling by-product with Saccharomyces cerevisiae 5, 10, 20 g/Kg diet (FY) (a carbohydrate source) on fish growth, health, maturity, and reproductive performance. The broodstock were divided into four groups: FY0, FY5, FY10, and FY20 diet, and control (FY0) fed a basal diet for 68 days. Growth-related parameters, biochemical composition, and blood biochemical parameters were measured. For maturity progress ovarian histology, gonadotropins and sex steroid hormones (T and E2) were noticed, and to evaluate reproductive performance, fecundity and gonadosomatic index (GSI%) were evaluated. Adding FY to the experimental diets improved broodstock growth and hematological markers. Additionally, it enhanced the ovarian growth (GSI% and fecundity), which augmented significantly (p ≤ 0.05) in FY10 and. FY20 treated sets. Dietary FY significantly increased serum levels of globulin, albumin, total protein, and glucose compared with the control. In addition, gonadotropins and sex hormones were significantly elevated in a dose-dependent mode with increasing FY levels. This study demonstrated positive physiological effects with improving reproductive parameter response after FY dietary addition. The group fed FY20 exhibited the better growth performance than the other treatments. Therefore, nutritional FY management could be employed as a tactical approach to improve reproductive ability and maintain goldfish production.

Differential polyvalent passive immune protection of egg yolk antibodies (IgY) against live and inactivated Vibrio fluvialis in fish

Egg yolk antibodies (IgY) can be prepared in large quantities and economically, and have potential value as polyvalent passive vaccines (against multiple bacteria) in aquaculture. This study prepared live and inactivated Vibrio fluvialis IgY and immunized Carassius auratus prior to infection with V. fluvialis and Aeromonas hydrophila. The results showed that the two IgY antibodies hold effective passive protective rates against V. fluvialis and A. hydrophila in C. auratus. Further, the serum of C. auratus recognized the two bacteria in vitro, with a decrease in the bacteria content of the kidney. The phagocytic activity of C. auratus plasma was enhanced, with a decrease in the expression of inflammatory and antioxidant factors. Pathological sections showed that the kidney, spleen, and intestinal tissue structures were intact, and apoptosis and DNA damage decreased in kidney cells. Moreover, the immunoprotection conferred by the live V. fluvialis IgY was higher than that of the inactivated IgY. Addition, live V. fluvialis immunity induced IgY antibodies against outer membrane proteins of V. fluvialis were more than inactivated V. fluvialis immunity. Furthermore, heterologous immune bacteria will not cause infection, so V. fluvialis can be used to immunize chickens to obtain a large amount of IgY antibody. These findings suggest that the passive immunization effect of live bacterial IgY antibody on fish is significantly better than that of inactivated bacterial antibody, and the live V. fluvialis IgY hold potential value as polyvalent passive vaccines in aquaculture.

Effects of sub-lethal copper sulfate exposure on blood parameters and metabolic enzymes activity in prussian carp, Carassius auratus from river of Shatt Al-Arab, Iraq

Effects of sub-lethal copper sulfate exposure on blood parameters and metabolic enzymes activity in prussian carp, Carassius auratus from river of Shatt Al-Arab, Iraq

Histopathological and molecular responses of goldfish (Carassius auratus) exposed to sodium and manganese sulfates

Histopathological and molecular responses of goldfish (Carassius auratus) exposed to sodium and manganese sulfates