Differences in growth of Trypanoplasma borreli in carp serum is dependent on transferrin genotype.

Kinetoplastid parasites require transferrin (Tf), being the main source of iron, for growth and multiplication. This group of parasites developed a unique receptor-mediated system for acquiring host Tf which bears no structural homology with the host transferrin receptor. Trypanoplasma borreli, a blood parasite of common carp, probably uses a similar mechanism to sequester iron from host transferrin. In this study, we demonstrate a critical role of Tf for parasite growth. For in vitro studies we isolated and purified Tf from carp homozygous for the D or G allele of Tf. We obtained Tf-depleted serum using specific antibodies to carp Tf and studied gene expression in vivo during T. borreli infection with Real Time-quantitative PCR. We demonstrate that T. borreli cannot survive in medium supplemented with Tf-depleted serum while reconstitution with Tf restores normal growth. The critical role of Tf for parasite survival was shown in incomplete medium (medium without serum): addition of purified Tf significantly increased parasite survival. We also demonstrate that Tf polymorphism has a significant impact on T. borreli multiplication. Cultured parasites die more quickly in an environment containing D-typed Tf, as compared to medium with G-typed Tf. Gene expression during T. borreli infection in carp did not show an acute phase response. We could, however, observe an increased transcription of Tf in the head kidney, which may be associated with an immunological function of the Tf protein.

Effects of dietary marjoram, Origanum majorana extract on growth performance, hematological, antioxidant, humoral and mucosal immune responses, and resistance of common carp, Cyprinus carpio against Aeromonas hydrophila.

The present study aimed to investigate the potential effects of dietary marjoram extract on growth performance, health, and disease resistance in common carp, Cyprinus carpio. To this purpose, the fish were assigned into four treatments and fed by diets supplemented with 0 (control), 100, 200, and 400 mg marjoram extract kg-1 over eight weeks and then challenged with Aeromonas hydrophila. According to the results, 200 mg kg-1 dietary marjoram extract inclusion showed the highest final weight, weight gain, and specific growth rate, and lowest feed conversion ratio (FCR). White blood cell number, Red blood cells, hematocrit, hemoglobin, mean corpuscular volume and mean corpuscular hemoglobin were markedly increased particularly at 200 mg kg-1 treatment. Marjoram extract significantly increased plasma superoxide dismutase activity and decreased malondialdehyde level compared to the control treatment. Plasma complement and lysozyme activities and total immunoglobulin levels, mucosal complement, lysozyme and alkaline phosphatase activities and immunoglobulin levels were significantly increased compared to the control group. The lowest post-challenge survival rate was observed in the control treatment, whereas the highest value was related to the 200 mg kg-1 marjoram treatment. In conclusion, the present study demonstrated that, marjoram extract is a suitable feed supplements for common carp, as it stimulates the fish growth, antioxidant, and immune systems, which suppress the fish mortality during Aeromonas septicemia. According to the results, 200 mg marjoram extract kg-1 is recommended for carp feed formulation.

Modulatory effects of laurel-leaf cistus (Cistus laurifolius) ethanolic extract on innate immune responses and disease resistance in common carp (Cyprinus carpio).

Medicinal herbs are used for growth promotion, disease control and other health benefits in aquaculture industry. Here, we examined the effect of dietary laurel-leaf cistus (Cistus laurifolius) ethanolic extract on growth performance, digestive enzyme activity, haematological profile and nonspecific immune responses in common carp (Cyprinus carpio). In addition, resistance against Aeromonas hydrophila infection was examined. Common carp was fed diets containing 0 (Control), 0.1 (CL0.1), 0.5 (CL0.5) and 1 (CL1) g kg-1 laurel-leaf cistus extract for 45 days. After 30 days, superoxide anion production (SAP) increased in CL0.1 and CL0.5 fish groups and at the end of the study all experimental fish groups had higher SAP compared to that of the control (P ˂ 0.05). Lysozyme activity (LA) was elevated in CL0.5 and CL1 treated groups on 30th day (P < 0.05), and this increase was only observed in C0.1 fish group at the end of study compared to control (P ˂ 0.05). Myeloperoxidase activity was significantly increased in CL0.5 and CL1 fish groups at the end of study. IL-1ßgene expression was significantly increased in treated fish in a dose-depended manner. Similar results were observed for transcription of IL-6 and IL-8 (P < 0.05). Anti-inflammatory cytokines, IL-10 and TGF-ß were highly up-regulated in the intestine and head kidney of CL treated fish groups compared to control (P < 0.05). At the end of experiment, significantly higher final body weight, weight gain, and specific growth rate were obtained in CL0.1 treated fish group compared to control. However, growth was negatively affected in CL1 fish group (P < 0.05). CL1 fish group had also a significantly higher FCR. Amylase activity was significantly increased in all experimental fish groups compared to control (P ˂ 0.05). Trypsin activity was decreased in CL0.1 and CL1 fish groups (P ˂ 0.05). WBC and RBC were significantly increased (P ˂ 0.05) in CL0.5 and CL1 fish groups, whereas haemoglobin, haematocrit, mean cell, mean cell haemoglobin contents were no significantly changed among control and treatment groups. Result of challenge test with A. hydrophila exhibited that survival rate in all treatment groups was significantly higher than that of control. These findings demonstrated that laurel-leaf cistus at 0.1 g kg-1 can be a suitable candidate for growth promotion, immune system induction and infection control in fish.

Sulfadiazine pharmacokinetics in grass carp (Ctenopharyngodon idellus) receiving oral and intravenous administrations.

This study aimed to examine the bioavailability (BA) and pharmacokinetic (PK) characteristics of sulfadiazine (SDZ) in grass carp (Ctenopharyngodon idellus) after oral and intravenous administrations. Blood samples were collected at predetermined time points of 0.083, 0.17, 0.5, 1, 2, 4, 8, 16, 24, 48, 72, and 96 hr (n = 6). The samples were extracted and purified by organic reagents and determined by the ultra-performance liquid chromatography. The software named 3P97 was used to calculate relevant PK parameters. The results demonstrated that the concentration-time profile of SDZ was best described by a one-compartmental open model with first-order absorption after a single oral dose. The main PK parameters of the absorption rate constant (Kα ), the absorption half-life (t1/2 Kα ), the elimination rate constant (Ke ), the elimination half-life (t1/2Ke ), and the area under concentration-time profile (AUC0-∞ ) were 0.3 1/h, 2.29 hr, 0.039 1/h, 17.64 hr, and 855.78 mg.h/L, respectively. Following intravenous administration, the concentration-time curve fitted to a two-compartmental open model without absorption. The primary PK parameters of the distribution rate constant (α), the elimination rate constant (ß), the distribution half-life (t1/2α ), the elimination half-life (t1/2ß ), the apparent distribution volume (VSS ), the total clearance (CL), and AUC0-∞ were 9.62 1/hr, 0.039 1/hr, 0.072 hr, 17.71 hr, 0.33 L/kg, 0.013 L h-1  kg-1 , and 386.23 mg.h/L, respectively. Finally, the BA was calculated to be 22.16%. Overall, this study will provide some fundamental information on PK properties in the development of a new formulation SDZ in the future and is partially beneficial for the appropriate usage of SDZ in aquaculture.

High stocking density alters growth performance, blood biochemical profiles, and hepatic antioxidative capacity in gibel carp (Carassius gibelio).

This study investigated the effect of stocking density on growth performance, blood biochemical profiles, antioxidative capacity, and muscle quality of gibel carp (Carassius gibelio). Gibel carps (initial body weight 57.04 ± 1.89 g) were reared at high stocking density (HSD, 10.85 kg m-3), medium stocking density (MSD, 5.06 kg m-3), and low stocking density (LSD, 1.47 kg m-3) for 60 days. The LSD group exhibited the highest growth rate, while HSD significantly inhibited fish growth. The muscular compositions of crude fat, crude ash, and moisture were significantly changed by stocking density, but crude protein content did not differ significantly. The stocking density altered the muscular texture profiles of gibel carp. Compared to either the HSD group or the MSD group, the highest levels of resilience and springiness occurred in the LSD group. Significant differences were observed in the levels of plasma glucose, alanine aminotransferase, aspartate aminotransferase, cholesterol, and creatinine among three groups. The fish exhibited the highest level of plasma cortisol as well as the lowest levels of triiodothyronine and thyroxine in the HSD group. The fish stocked in the LSD group showed the highest activities of superoxide dismutase, glutathione peroxidase, and catalase as well as the highest content of glutathione in liver. The significant highest total antioxidant capacity occurred in the fish stocked in the LSD group. The results showed that HSD resulted in chronic crowding stress, and exerted negative impact on growth performance, muscle quality, and antioxidative capacity of gibel carp.

Protein kinase A activity and NO are involved in the regulation of crucian carp (Carassius carassius) red blood cell osmotic fragility.

Activation of the cAMP pathway by ß-adrenergic stimulation and cGMP pathway by activation of guanylate cyclase substantially affects red blood cell (RBC) membrane properties in mammals. However, whether similar mechanisms are involved in RBC regulation of lower vertebrates, especially teleosts, is not elucidated yet. In this study, we evaluated the effects of adenylate cyclase activation by epinephrine and forskolin, guanylate cyclase activation by sodium nitroprusside, and the role of Na+/H+-exchanger in the changes of osmotic fragility and regulatory volume decrease (RVD) response in crucian carp RBCs. Western blot analysis of protein kinase A and protein kinase G substrate phosphorylation revealed that changes in osmotic fragility were regulated via the protein kinase A, but not protein kinase G signaling pathway. At the same time, the RVD response in crucian carp RBCs was not affected either by activation of adenylate or guanylate cyclase. Adenylate cyclase/protein kinase A activation significantly decreased RBC osmotic fragility, i.e., increased cell rigidity. Inhibition of Na+/H+-exchanger by amiloride had no effect on the epinephrine-mediated decrease of RBC osmotic fragility. NO donor SNP did not activate guanylate cyclase, however affected RBCs osmotic fragility by protein kinase G-independent mechanisms. Taken together, our data demonstrated that the cAMP/PKA signaling pathway and NO are involved in the regulation of crucian carp RBC osmotic fragility, but not in RVD response. The authors confirm that the study has no clinical trial.

The blood and mRNA levels of antioxidant-related factors in common carp (Cyprinus carpio) fed p-Coumaric acid.

The natural antioxidants are well known for their antioxidative activity without side effects when compared to antibiotics. Hence, the present study aimed at evaluating p-Coumaric acid as an antioxidant additive on the blood and mRNA levels of antioxidant-related factors in common carp (Cyprinus carpio). Fish fed the basal diet supplemented with p-Coumaric at 0, 0.5, 1, and 1.5 g/kg for 56 days, then the serum, intestine, and liver samples were collected. The growth performance of fish fed with CA showed significantly (P < 0.05) improved FW, WG, and SGR compared to those of the control one. However, the feed conversion ratio was significantly (P < 0.05) reduced in fish fed 1 and 1.5 g/kg diet levels. SOD was not significantly differed among the groups fed with varied p-Coumaric acid (P > 0.05). Serum GPX and TAC were enhanced considerably by p-Coumaric acid regarding the control with the highest being in fish fed 1.5 g/kg diet (P < 0.05). Serum CAT was more elevated in fish provided p-Coumaric acid at 1 or 1.5 g/kg than the control while fish fed 0.5 g/kg did not display significant changes. MDA level significantly decreased by all p-Coumaric acid groups compared to the control one, and the lowest level was observed in 1.5 g/kg (P < 0.05). The mRNA level of CAT was significantly upregulated in the liver by p-Coumaric acid at 1 or 1.5 g/kg (P < 0.05), while the intestine CAT did not influence by p-Coumaric acid (P > 0.05). The measured SOD in the liver and intestine samples revealed no changes in common carp fed p-Coumaric acid (P > 0.05). GPX was significantly upregulated in the intestine by p-Coumaric acid at 1 or 1.5 g/kg (P < 0.05), whereas the liver GPX was upregulated by p-Coumaric acid at 1.5 g/kg. The mRNA level of the GST gene in the intestine of common carp was upregulated by p-Coumaric acid at 1.5 g/kg, whereas the liver displayed upregulated GST in fish fed 1 g/kg diet. The present study approved the application of p-Coumaric acid as a natural antioxidant for friendly, sustainable aquaculture.

Dietary selenium promotes the growth performance through growth hormone-insulin-like growth factor and hypothalamic-pituitary-thyroid axes in grass carp (Ctenopharyngodon idella).

Selenium (Se), an essential component of deiodinases (DIOs), regulates the contents of thyroid hormones and thus improves animal growth. To explore the influences of selenium supplementation on fish growth metabolism, a total of 270 healthy grass carp (Ctenopharyngodon idella) were divided into three groups and feed three graded dietary selenium (0.141, 0.562, and 1.044 mg Se/kg) levels. The results showed that after 60-day feeding, dietary selenium improved the final body weight and specific growth rate (SGR) of grass carp. The hepatic DIO activities in selenium-supplemented groups were higher than those in control group. A significant increase in triiodothyronine (T3), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) levels was accompanied by a decrease in the contents of thyroxine (T4) and free thyroxine (FT4) in selenium-supplemented groups. The histopathological observation of thyroid suggested that selenium deficiency resulted in hypertrophy of follicular epithelial cells. Moreover, the gene relative expression levels of dio1, dio2, and dio3 showed an increasing trend with the rising concentration of dietary selenium. The transcription levels of HPT axis-related genes (crh, tsh-ß, ttr, tr-s, tpo, nis) and GH/IGF1-related genes (gh, ghr, igf1, igf1r) were significantly upregulated in selenium-supplemented groups. No significant differences in the above indicators were observed between 0.562 and 1.044 mg Se/kg diet group except T3 content and dio1 relative expression ratio. These results indicate that dietary selenium supplementation improves the hepatic DIO activities and thyroid hormone metabolism and regulates the transcription levels of HPT and GH/IGF axis-related genes, which may be responsible for the growth promotion in grass carp.

Gonad development and reproductive hormones of invasive silver carp (Hypophthalmichthys molitrix) in the Illinois River.

Reproduction is a major component of an animal's life history strategy. Species with plasticity in their reproductive biology are likely to be successful as an invasive species, as they can adapt their reproductive effort during various phases of a biological invasion. Silver carp (Hypophthalmicthys molitrix), an invasive cyprinid in North America, display wide variation in reproductive strategies across both their native and introduced ranges, though the specifics of silver carp reproduction in the Illinois River have not been established. We assessed reproductive status using histological and endocrinological methods in silver carp between April and October 2018, with additional histological data from August to October 2017. Here, we show that female silver carp are batch spawners with asynchronous, indeterminate oocyte recruitment, while male silver carp utilize a determinate pattern of spermatogenesis which ceases in the early summer. High plasma testosterone levels in females could be responsible for regulating oocyte development. Our results suggest that silver carp have high spawning activity in the early summer (May-June), but outside of the peak spawning period, female silver carp can maintain spawning-capable status by adjusting rates of gametogenesis and atresia in response to environmental conditions, while males regress their gonads as early as July. The results of this study are compared to reports of silver carp reproduction in other North American rivers as well as in Asia.

Ginger (Zingiber officinale) extract affects growth performance, body composition, haematology, serum and mucosal immune parameters in common carp (Cyprinus carpio).

The present study was designed to investigate the dietary effects of ginger extract (Zingiber officinale) on common carp (Cyprinus carpio). Three hundred and sixty fish weighing 10.9 ± 0.17 g were randomly divided into four experimental treatments in triplicates. Four experimental diets were designed containing different inclusion levels of ginger extract as 0% (control), 0.1%, 0.2%, and 0.4% named T1, T2, T3, and T4, respectively, and fish were fed 3% of body weight daily for 60 days. Feed conversion ratio, weight gain, and specific growth rate parameters were measured higher in the groups fed with ginger extract compared to the control, especially in T3 (P < 0.05). Also, fish treated with ginger extract showed lower carcass moisture and lipid, but higher protein contents compared to the control. The results showed significant increase in the number of erythrocytes and leucocytes, as well as the level of hematocrit and hemoglobin in fish fed with supplemented diets. In addition, significant enhancement was observed in cases of serum parameters, including total protein, albumin, globulin, lysozyme, superoxide dismutase, catalase, and total immunoglobulins in T3 and T4 compared to the control. The lowest serum cortisol level was noticed in T3. Furthermore, the T3 group showed the highest activities of skin mucus lysozyme, alkaline phosphatase, and protease (P < 0.05). In conclusion, the present results demonstrated that Zingiber officinale extract at a 0.2% level can effectively improve the growth and health status of Common Carp (Cyprinus carpio).

Effects of dietary fern (Adiantum capillus-veneris) leaves powder on serum and mucus antioxidant defence, immunological responses, antimicrobial activity and growth performance of common carp (Cyprinus carpio) juveniles.

A 56-day research was performed to examine the influence of graded levels (0 (control), 0.5, 1 and 2%) of Fern (Adiantum capillus-veneris) leaves powder (FLP) in diet on immune competence and growth of common carp (Cyprinus carpio, initial weight = 20 g). The serum total immunoglobulins content and lysozyme activity in the 1 and 2% FLP groups remarkably increased compared to the other groups (P < 0.05). The skin mucosal lysozyme activity enhanced with increasing dietary FLP level in a dose-response manner. Fish fed on the FLP-supplemented diets had higher skin-mucosal superoxide dismutase activity than the control (P < 0.05). However, serum antioxidant enzymes were not affected by dietary fern (P > 0.05). The serum bactericidal activity against human and fish pathogens increased with enhancing the FLP level in diet against Staphylococcus aureus, Escherichia coli (EHEC ATCC 43895), Escherichia coli (CI), Pseudomonas aeruginosa, Klebsiella pneumonia and Aeromonas hydrophila. The serum antibacterial activity against Yersinia ruckeri in the 2% FLP group was higher than the other treatments. Furthermore, the serum bactericidal activity against P. aeruginosa (ATCC 27853) only observed in fish fed on the 1 and 2% FLP-supplemented diets. The skin mucosal bactericidal activity and inhibitory effects increased with enhancing the FLP level in diet against E. coli, K. pneumonia, Y. ruckeri and A. hydrophila in a dose response manner. Moreover, the skin mucosal bactericidal activity against S. aureus only observed in fish fed on 1 and 2% FLP-supplemented diets. The weight gain values in the 1 and 2% FLP groups were higher than the other treatments (P < 0.05). Feed conversion ratio (FCR) improved with increasing FLP level in diet in a dose-response manner (P < 0.05). By considering serum and mucosal bactericidal activities against different pathogenic bacteria, the supplementation of 2% FLP in diet is recommended for C. carpio during grow-out phase.

Surface display of spring viremia of carp virus glycoprotein on Lactococcus lactis and its protection efficacy in common carp (Cyprinus carpio L.).

Spring viremia of carp virus (SVCV) causes devastating disease in aquaculture, resulting in significant economic impact. To develop an effective means against SVCV infection, a Lactococcus lactis (L.lactis) based subunit vaccine (pNZ-UGA) was developed based on surface displaying of SVCV glycoprotein using anchoring motif of the cA (C terminus of the peptidoglyvsn-binding) domains of AcmA, a major autolysin from L.lactis. The surface expression of SVCV glycoprotein was verified by indirect immunofluorescence assay. The efficacy of the constructed vaccine was further evaluated in common carp. The results showed that the higher levels of specific IgM could be detected in fish vaccinated with pNZ-UGA, compared with that in PBS and L.lactis groups. Immune-related genes including TNF-α, IL-6b, IL-1ß, Cxcr 1, Cxca, IFNg2b, I-IFN, and IgM expression in pNZ-UGA group were strongly up-regulated, revealing that robust innate immune response was induced. Notably, the lowest cumulative mortality (13.46%) was observed in fish vaccinated with pNZ-UGA vaccine after SVCV challenge, whereas the cumulative mortality were 100.00% and 92.31% in PBS and L.lactis groups, respectively. This study suggests the potential use of the recombinant L.lactis with surface displaying antigen proteins as effective vaccines against SVCV and other fish virus infection.

The potential benefits of orange peels derived pectin on serum and skin mucus immune parameters, antioxidant defence and growth performance in common carp (Cyprinus carpio).

This study was performed to determine the effects of pectin derived from orange peel (PDOP) on growth performance, antioxidant enzyme activity and serum and skin mucus immune response of common carp (Cyprinus carpio). Common Carp (16.94 ± 0.03 g) were distributed into 12 tanks representing four treatments repeated in triplicates. Four diets were prepared to contain four levels of PDOP as follows: 0 (control), 0.5, 1, and 2% PDOP. Growth and immunological parameters as skin mucus lysozyme activity (SMLA) and total immunoglobulin (SMTIg), serum total immunoglobulin (STIg), serum peroxidase activities (SPA), Catalyse activity (CAT), DPPH radical scavenging activity, specific growth rate (SGR), weight gain (WG), final weight (FW), and feed conversion ratio (FCR) were assessed. Fish fed diets supplemented with PDOP showed an improvement of SGR, WG, FW, and FCR (P < 0.05). In terms of skin mucus immunological parameters, dietary inclusion of pectin significantly (P < 0.05) increased SMTIg. Likewise, carps fed either 1 or 2% PDOP showed notable enhancement of SMLA. In the case of serum immune parameters and antioxidant defence, carps in 1% PDOP treatment showed significantly (P < 0.05) higher SPA and CAT compared to fish fed either control diet or 0.5% OPDP. Additionally, no significant change (P > 0.05) was found in SPA and CAT of fish fed either 1% PDOP or 2% PDOP. Also, no significant (P > 0.05) difference was noticed between treated groups and control in the case of STIg. Furthermore, no significant differences were observed in DPPH radical activity among treatments (P > 0.05). Overall, these results suggested that inclusion of PDOP in common carp diet can beneficially affect growth and immune response.

High temperature acclimation alters upper thermal limits and growth performance of Indian major carp, rohu, Labeo rohita (Hamilton, 1822).

Increase in water temperature due to anthropogenic and climatic changes is expected to affect physiological functions of fish. In this study, we determined high temperature tolerance (CTmax) of a common aquacultured Indian major carp, rohu, Labeo rohita fingerlings (15.96 ± 0.72 g BW, 11.56 ± 0.42 cm TL) followed by acclimatization at three temperatures (30, 33, 36 °C). To determine the CTmax, we analyzed the major hemato-biochemical indices - hemoglobin (Hb), red blood cell (RBC), white blood cell (WBC), blood glucose levels, and erythrocytic nuclear abnormalities (ENAs) and erythrocytic cellular abnormalities (ECAs) of peripheral erythrocytes in the fish sampled at the start and end point at each acclimated temperature. Significantly decreased CTmax of the fish was found at 36 °C compared to 30 °C and 33 °C. The fish in the highest (36 °C) temperature were found with significantly lower Hb and RBC content and significantly higher WBC and blood glucose levels than that of the fishes in the lowest (30 °C) temperature both at the start and end points. The highest frequencies of ENAs and ECAs were found in the highest (36 °C) temperature group compared to the lowest (30 °C) temperature group at both the points. We also evaluated growth performance of the rohu fingerlings reared in the three temperatures for 60 days. The growth parameters - final weight gain, percent weight gain and specific growth rate were the highest at 33 °C and the lowest at 36 °C. The present study revealed that the highest temperature (36 °C) tested here may be hazardous to rohu and the temperature should be kept below 36 °C in the aquaculture setting to avoid physiological damage and growth and production loss to the fish.

Ammonia excretion and blood gas variation in naked carp (Gymnocypris przewalskii) exposed to acute hypoxia and high alkalinity.

Naked carp (Gymnocypris przewalskii), endemic to the saline-alkaline Lake Qinghai, have the capacity to tolerate combined hypoxia and high alkalinity. This study evaluated the effect of the interaction between carbonate alkalinity and hypoxia on ammonia excretion and blood gas variation in naked carp. Naked carp were subjected to normoxic, hypoxic and reoxygenation phases at two different carbonate alkalinity levels (CA0 = 0 mmol/L; CA32 = 32 mmol/L) for 4 days. The ammonia excretion rate (JAmm) of the CA0 group rapidly decreased under hypoxia and recovered under normoxia for four consecutive days. The JAmm under CA32 also decreased under hypoxia and recovered to its previous level in the first 2 days. However, the JAmm under CA32 was lower than that under CA0. The blood pO2, sO2 of CA0 and CA32 group was significantly reduced under hypoxia, after which both groups recovered. Blood pCO2 of the CA32 group was lower than CA0 throughout the experiment. There were no changes in haematocrit of the naked carp exposed to carbonate alkalinity and hypoxia. The alkaline water increased the pH of the blood and contributed to increased haemoglobin O2 affinity. Overall, the present findings reveal that naked carp is a tolerant species that can maintain main ionic homeostasis under severe alkalinity and hypoxia. The high alkaline water is beneficial for naked carp to adapt to hypoxic environment.

Protective effects of metallothionein and vitamin E in the trunk kidney and blood of cadmium poisoned Ctenopharyngodon idellus.

Cadmium (Cd), a substance with one of the most critical health hazard indices, can cause damage to both the blood and kidneys and accumulates in the body at last. The present work studied the toxicological effects of Cd and the therapeutic effects of metallothionein (MT) and vitamin E (VE) on the trunk kidney and blood of freshwater grass carp (Ctenopharyngodon idellus). Grass carp were divided into three groups: Cd + phosphate-buffered saline (PBS) group, Cd + VE group, and the Cd + MT group. Fish were injected with CdCl2 on the first day and then VE, MT, or PBS was administered 4 days post-injection. Fish not injected with Cd were used as a negative control. The blood and trunk kidney amassed Cd and suffered severe damage in the forms of organ toxicity cytotoxicity, and immunotoxicity. However, the MT reduced the Cd content in the trunk kidney and blood and partially stabilized the damaged organs. Treatment with VE, however, only demonstrated weaker protection against on Cd-induced toxicity. The results indicate that exogenous MT may play an essential role in restoring homeostasis of the Cd-poisoned urinary and circulatory system and that it may help eliminate Cd in aquatic animals.

THE EFFECT OF ANESTHETIC TIME AND CONCENTRATION ON BLOOD GASES, ACID-BASE STATUS, AND ELECTROLYTES IN KOI (CYPRINUS CARPIO) ANESTHETIZED WITH BUFFERED TRICAINE METHANESULFONATE (MS-222).

Anesthesia is commonly employed in aquatic medicine to facilitate physical exams, diagnostics, and surgical interventions. Tricaine methanesulfonate (MS-222) is the most commonly used anesthetic for fish and is currently the only anesthetic approved by the US Food and Drug Administration Center for Veterinary Medicine for food-producing fish. Despite the frequency of anesthetic procedures in fish, anesthetic monitoring remains rudimentary in many facilities. This study evaluated the impact on blood gases, acid-base balance, and electrolytes in koi (Cyprinus carpio) anesthetized at concentrations of 100 mg/L and 150 mg/L MS-222. Blood samples from 25 fish per treatment were collected at 5 and 20 min of anesthetic immersion. Forty-nine of 50 fish recovered uneventfully from anesthesia; one fish did not recover and was euthanatized. Results showed significant increases in partial pressure of carbon dioxide (pCO2) (P = 0.006) and hyperglycemia (P = <0.0001) with increasing anesthetic concentration and time under anesthesia and a significant decrease in partial pressure of oxygen (pO2) with increased anesthetic time (P = 0.021). There were several electrolyte changes observed with both increasing anesthetic time and concentration. All electrolytes except potassium remained within published reference ranges for koi, while potassium showed a significant decrease in concentration associated with anesthetic time and concentration. The results of this study indicate that MS-222 at 100 mg/L and 150 mg/L represent safe anesthetic concentrations for koi undergoing minimally invasive diagnostics; however, koi anesthetized with MS-222 at a concentration of 150 mg/L experienced more significant changes in blood gases, acid-base balance, and electrolyte concentrations.

Analysis of O-Acetylated Sialic Acids in Dried Blood Spots.

Sialic acid is a family of N- and O-substitutions of neuraminic acid. Plasma or serum sialic acid has been established as a potential disease marker. For example, the presence of 9- O-acetyl on the sialic acid of some glycans and glycoconjugates (e.g., 9- O-acetyl GD3 ganglioside) could be related to cancer occurrence. A variety of assays are available to measure serum or plasma sialic acid; however, sample preparation and storage can alter the O-acetylation profile due to the loss of O-acetyl groups and/or the migration of O-acetyl groups. Herein, we report dried blood spot (DBS) sampling, in combination with diamino-4,5-methylenedioxybenzene derivatization, for profiling sialic acids in blood samples with minimal alteration in O-acetylation patterns. The feasibility of the method was first evaluated by analyzing sialic acids in crucian carp blood and comparing with traditional blood/plasma sample preparation procedures. A total of 19 different sialic acids were identified by using liquid chromatography-Orbitrap mass spectrometry, including four mono-O-acetylated N-acetylneuraminic acids, four mono-O-acetylated N-glycolylneuraminic acids, six di-O-acetylated N-acetylneuraminic acids, and three tri-O-acetylated N-acetylneuraminic acids. The long-term storage study indicated that DBS sampling could effectively preserve the O-acetylation information for at least 6 weeks. Thus, it is demonstrated that this method is a valuable tool for the study of sialic acid diversity, especially for the characterization of isomeric structures.

Hematological analysis of Ctenopharyngodon idella, Megalobrama amblycephala and Pelteobagrus fulvidraco: Morphology, ultrastructure, cytochemistry and quantification of peripheral blood cells.

The grass carp (Ctenopharyngodon idella), blunt snout bream (Megalobrama amblycephala) and yellow catfish (Pelteobagrus fulvidraco) are economically important fishes in China. Fish hematological features, especially the type and number of peripheral blood cells, are crucial for the evaluation of fish health and the diagnosis of fish diseases. Since the automatic blood cell count equipment for human is not suitable for fishes, the manual method is critical in the quantification of fish blood cells. To make sense of the comparison and interpretation of the blood cell count studies in different articles, the standardization of blood cell classification is necessary. In this study, erythrocytes (red blood cell, RBC), thrombocytes (TC) and leucocytes (i.e. white blood cells, WBC, including lymphocytes, neutrophils and monocytes) were well distinguished in blood smears with Giemsa staining and confirmed by transmission electron microscopy. RBC, TC and WBC were directly counted with an improved Neubauer counting chamber in a modified diluting solution. The differential leucocyte count (DLC) was carried out in blood smears. In view of the labeling characteristics of peroxidase (PO) positivity in neutrophils and non-specific esterase (α-ANAE) positivity in monocytes, PO positive cell percentage and α-ANAE positive cell percentage were also determined in cytochemistry staining smears. No difference was found for the percentages of neutrophils and monocytes between Giemsa staining and cytochemistry staining. The standardized classification, normal count ranges and sizes of the peripheral blood cells by the present systemic studies will provide useful references for monitoring the health status of grass carp, blunt snout bream and yellow catfish.

Dietary supplementation of olive leaf extract increases haematological, serum biochemical parameters and immune related genes expression level in common carp (Cyprinus carpio) juveniles.

The present study investigated the effects of dietary olive leaf (Olea europea L.) extract (OLE) on some blood parameters and immune (TNF-α, IL-1ß and IL-8) related genes in different tissues (head kidney, liver and spleen) and resistance of common carp, Cyprinus carpio to Edwardsiella tarda. Five diets were prepared for fed fish (mean body weight 15.90 ±â€¯0.93 g) with different rates of OLE (0.0%, 0.1%, 0.25%, 0.50% and 1.0%). A control diet was prepared non-supplemented with OLE. Increased haematocrit ratio, serum myeloperoxidase activity, immune response gene levels (IL-1ß in head kidney tissue and TNF-α in spleen tissue) and survival rate against E. tarda particularly in the 0.1% OLE treatment group. In conclusion, results of the present study show that feeding common carp with a diet containing 1 g/kg OLE over a period of 60 days might be adequate to improve fish immune parameters, and survival rate against E. tarda. Therefore, OLE can be used as a dietary additive to prevent E. tarda in common carp.