Juvenile Common Carp Research Articles

Responses of the hepatic glutathione antioxidant defense system and related gene expression in juvenile common carp after chronic treatment with tributyltin.

Recently, residual organotin compounds have generally been recognised as relevant sources of aquatic environmental pollutants. However, the effects of these contaminants on the glutathione (GSH)-antioxidant system of fishes have not been adequately studied. In the current study, the chronic effects of tributyltin (TBT) found within antifouling paints for ships, on the GSH antioxidant system and related gene expression in the liver of juvenile common carp (Cyprinus carpio) were investigated. Fishes were exposed to sub-lethal concentrations of TBT (75ng/L, 0.75 and 7.5μg/L) for 15, 30 and 60days. GSH levels and GSH-related enzymes activities, including glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), were quantified in the fish liver. The levels of malondialdehyde were also measured as a marker of oxidative damage. In addition, the expression levels of gstp1, gr and gpx1 in common carp chronically exposed to TBT were determined. The results of the current study indicate that chronic exposure of TBT results in reactive oxygen species stress in the liver of common carp, and mRNA expression levels are more sensitive than related enzyme levels. In short, the measured GSH-related indices could potentially be used as molecular indicators for monitoring organotin compounds in the aquatic environment.

Chronic effects of tributyltin on multiple biomarkers responses in juvenile common carp, Cyprinus carpio.

In this study, the chronic toxic effects of tributyltin (TBT), an antifouling paints commonly present in surface and ground water, on morphological indices, reactive oxygen species (ROS) generation, and ATPase activity and heat shock protein (Hsp) 70 protein in tissues (liver, gill, and white muscle) of common carp were investigated. Fish were exposed at sublethal concentrations of TBT (75 ng/L, 0.75 μg/L, and 7.5 μg/L) for 60 days. When compared with the control, there was significant lower condition factor in fish exposed at the higher concentration of TBT. ROS levels in three tissues increased significantly at higher TBT concentrations (0.75 and 7.5 μg/L). The hepatic antioxidant enzymes (total antioxidative capacity and superoxide dismutase) activities were induced at higher concentrations (0.75 μg/L) of TBT. When compared with the hepatic antioxidant enzymes activities in fish exposed to 0.75 μg/L of TBT, there was a decreasing trend in those exposed to TBT with a concentration of 7.5 μg/L. However, all the antioxidant enzymes activities were significantly inhibited in gill and muscle of fish exposed to higher TBT concentrations (0.75 and 7.5 μg/L). Moreover, there was significant lower Na-K-ATPase in three tissues after long-term exposure to higher concentration of TBT, but a significant higher Hsp70 protein levels was observed. In short, environmental concentrations of TBT could not induce obvious impacts on fish, but long-term exposure to higher concentrations of TBT could affect seriously the health status of fish. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 937-944, 2016.

Effects of dietary Saccharomyces cerevisiae culture or live cells with Bacillus amyloliquefaciens spores on growth performance, gut mucosal morphology, hsp70 gene expression, and disease resistance of juvenile common carp (Cyprinus carpio)

Abstract A feeding experiment was conducted to examine the effects of dietary administration of brewer's yeast Saccharomyces cerevisiae culture or live cells with Bacillus amyloliquefaciens spores on the growth performance, gut mucosal morphology, general welfare, and disease resistance of juvenile common carp ( Cyprinus carpio ). Four practical diets were formulated, i.e. control diet, diet Y1 (supplemented with 1 g/kg Saccharoculture, a Korean-made S. cerevisiae culture product containing 10 7 CFU/g B. amyloliquefaciens spores), diet Y2 (supplemented with 2 g/kg S. cerevisiae culture, DVAQUA®, produced by Diamond V Mills Inc., IA, USA, as the positive control) and diet Y3 (supplemented with Changlijian, a local product with each gram containing 10 10 CFU live S. cerevisiae cells and 1.2 × 10 10 CFU B. amyloliquefaciens spores, at the recommended dose of 0.2 g product per kg feed). Each diet was randomly assigned to triplicate groups of 12 fish. The experiment was conducted in aquaria for 8 weeks. Results showed that the growth performances were not significantly improved in all treatment groups. Intestinal mucosal morphology analysis indicated that the posterior intestinal microvillus length in treatments Y1 and Y2 was significantly increased compared to control ( P P hsp70 gene expression was observed in the intestine for different dietary groups. In the liver, the expression was decreased in Y1 and Y2, while in Y3 the expression was significantly increased ( P A. hydrophila infection in common carp. In conclusion, lower level of S. cerevisiae culture with B. amyloliquefaciens spores (1 g/kg Saccharoculture ) may confer some beneficial effect to common carp, but the supplementation of live S. cerevisiae cells with B. amyloliquefaciens spores didn't provide any improvements under the present experimental conditions.

Dietary effect of Quillaja saponaria and/or Yucca schidigera extract on growth and survival of common carp Cyprinus carpio, their antioxidant capacity and metabolic response to hypoxic condition

This study evaluated dietary effects of extracts of Quillay Quillaja saponaria, and/or Yucca Yucca schidigera on growth and survival of juvenile common carp Cyprinus carpio, and their antioxidant capacity and metabolic response to low dissolved oxygen (DO) stress. For 8 weeks, fish were fed one of 4 different diets. The diets were supplemented with either 150 mg/kg Quillay (QS), 150 mg/kg Yucca (YS), the combination of 75 mg/kg Quillay and 75 mg/kg Yucca (M), or control diet (C) without addition of Quillay or Yucca. Growth and survival were monitored periodically. After rearing, fish were subjected to low DO stress, and after a week, antioxidant capacity (superoxide dismutase, glutathione peroxidase and glutathione reductase) and metabolic response (glucose, triglycerides and lactate) were analyzed. QSfed fish had the highest weight gain among all the treatments. Treatments did not affect fish survival a week after low DO stress. Among antioxidant capacity and metabolic response, significant effects were found only on superoxide dismutase and glucose. QS fed fish had 39% lower plasma superoxide dismutase than the C and M groups. QS and M groups exhibited 29% and 26% lower plasma glucose than the C group, respectively. Overall, the QS diet improved growth and exhibited favorable antioxidant capacity and metabolic response of carp to low dissolved oxygen environment.

Dietary effect of Quillaja saponaria and/or Yucca schidigera extract on growth and survival of common carp Cyprinus carpio, their antioxidant capacity and metabolic response to hypoxic condition

This study evaluated dietary effects of extracts of Quillay Quillaja saponaria, and/or Yucca Yucca schidigera on growth and survival of juvenile common carp Cyprinus carpio, and their antioxidant capacity and metabolic response to low dissolved oxygen (DO) stress. For 8 weeks, fish were fed one of 4 different diets. The diets were supplemented with either 150 mg/kg Quillay (QS), 150 mg/kg Yucca (YS), the combination of 75 mg/kg Quillay and 75 mg/kg Yucca (M), or control diet (C) without addition of Quillay or Yucca. Growth and survival were monitored periodically. After rearing, fish were subjected to low DO stress, and after a week, antioxidant capacity (superoxide dismutase, glutathione peroxidase and glutathione reductase) and metabolic response (glucose, triglycerides and lactate) were analyzed. QSfed fish had the highest weight gain among all the treatments. Treatments did not affect fish survival a week after low DO stress. Among antioxidant capacity and metabolic response, significant effects were found only on superoxide dismutase and glucose. QS fed fish had 39% lower plasma superoxide dismutase than the C and M groups. QS and M groups exhibited 29% and 26% lower plasma glucose than the C group, respectively. Overall, the QS diet improved growth and exhibited favorable antioxidant capacity and metabolic response of carp to low dissolved oxygen environment.

The efficacy of the oils of spearmint and methyl salicylate as new anesthetics and their effect on glucose levels in common carp (Cyprinus carpio L., 1758) juveniles

Abstract In aquaculture and fisheries research, anesthetics are generally necessary to ease handling and to minimize stress and physical injury of fish during various handling procedures. The purpose of this study was to evaluate the effects of two anesthetics of spearmint oil (SO) and methyl salicylate oil (MSO) on Cyprinus carpio (16.59 ± 0.43 g). Also, their effect on glucose values was investigated as well. Fish were exposed to different concentrations of the SO (3, 5 and 7 ml L − 1 ) and the MSO (1, 2 and 3 ml L − 1 ) for induction of anesthesia. Results showed that induction time decreased significantly with increasing of the concentration of the SO or the MSO ( P P P − 1 , respectively. In another experiment, common carp exposed to the SO (5 ml L − 1 ), the MSO (2 ml L − 1 ) and spearmint oil and methyl salicylate oil emulsion (CMSE), as a combination anesthetic, in order to their compare with each other. Anesthesia induction was more quickly in the CMSE group; Also, recovery was significantly quicker in the CMSE group compared to other treatments ( P P > 0.05). However, the glucose levels after recovery increased significantly in the MSO group ( P

Molecular responses in digestive tract of juvenile common carp after chronic exposure to sublethal tributyltin

The effect of long-term exposure to tributyltin (TBT) on the intestine-related biochemical biomarkers in common carp was investigated in this study. Fish were exposed at sub-lethal concentrations of TBT (75ng/L, 0.75 and 7.5μg/L) for 60 days. Multiple biomarkers were measured, including digestive enzymes (trypsin, lipase and amylase), antioxidant responses (malondialdehyde (MDA) and total antioxidative capacity (T-AOC)), RNA/DNA ratio and the expression of digestive-related genes (try, lipc and amy). TBT exposure at 0.75 and 7.5μg/L led to significantly inhibited activities of all digestive enzymes. At higher concentration of TBT, oxidative stress was apparent as reflected by the significant higher MDA content in the fish intestine, associated with an inhibition of T-AOC activities. After 60 days, the RNA/DNA ratio in fish intestine was significantly lower in groups exposed to TBT at higher concentrations (0.75 and 7.5μg/L). In addition, the expression levels of try, lipc and amy in intestine of all treated fish were inhibited, even at the environmental concentration (75ng/L). Our results suggest that long-term exposure to TBT could result in different responses of intestine-related biochemical biomarkers in fish, which could be used as new potential indicators for monitoring residual TBT present in aquatic environment.

Effects of atrazine and chlorpyrifos on DNA methylation in the liver, kidney and gill of the common carp (Cyprinus carpio L.)

Pesticide exposure has repeatedly been associated with cancers, although the molecular mechanisms behind this association are largely undetermined. Abnormal DNA methylation plays a key role in the process of some disease. However, little was known about the effect of pesticides on DNA methylation in the common carp. In this study, we investigated the mRNA levels of DNA methyltransferases (DNMTs) and methyl-CpG-binding protein DNA-binding domain protein 2 (MBD2) as well as the DNA methylation levels in the liver, kidney and gill of the common carp (Cyprinus carpio L.) after 40-d exposure to atrazine (ATR) and chlorpyrifos (CPF) alone or in combination, and a 40-d recovery period. Juvenile common carp were exposed to various concentrations of ATR (at concentrations of 4.28, 42.8 and 428μg/L), CPF (1.16, 11.6 and 116μg/L), and an ATR/CPF mixture (at concentrations of 1.13, 11.3 and 113μg/L). The results revealed that the levels of genomic DNA methylation decreased in all tissues after 40d of exposure to ATR and CPF either individually or in combination. Moreover, the mRNA expression of DNMTs was down-regulated in all treatment groups. In contrast, the mRNA expression of MBD2 was up-regulated. These results demonstrated that long-term exposure to ATR, CPF and ATR/CPF mixtures could disrupt genomic DNA. It might imply that DNA methylation is involved in the toxicity caused by ATR and CPF in the common carp.

Serum and ultrastructure responses of common carp (Cyprinus carpio L.) during long-term exposure to zinc oxide nanoparticles

The uptake of nanoparticles by aquatic organisms such as fish has raised concerns about the possible adverse effects of nanoparticles (NPs). In this study, we aimed to evaluate the toxicological effects in juvenile common carp exposed to zinc oxide nanoparticles (ZnO-NPs) for 12 weeks. The carp were exposed to 0 (control), 0.1, 0.3, 0.8, and 2.4mg/L of ZnO-NPs under a flow-through exposure system. Fish were sampled at 0, 4, 8, and 12 weeks to test for zinc in the test water and blood, and biochemistry analysis; further, they were sampled at 12 weeks to observe ultrastructural changes in the liver, kidney, and gill. In the organic serum, changes in the glutamic pyruvic transaminase/alanine aminotransferase (GPT/ALT) and glutamic oxaloacetic transaminase/aspartate aminotransferase (GOT/AST) levels were significant, but changes in the lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) levels were not significantly different across all exposure periods. In the inorganic serum, the magnesium (Mg), inorganic phosphorus (IP), sodium (Na+), and chloride (Cl–) levels were significantly different in the exposure group and across exposure periods. However, calcium (Ca) and potassium (K+) levels were not significantly different. In the enzyme serum, the glucose (GLU) level significantly increased for the highest exposure group, but the total cholesterol (TCHO), triglyceride (Tg), and total protein (TP) levels were not significantly different during the exposure period. Ultrastructural changes in the liver induced changes in the black granules (of various sizes) in the lysosomes, indistinct nucleus membrane, and non-spherical nucleus. In the kidney, some mild changes were observed in the size and number of the lysosomes in the renal tubule. Desquamation and hypertrophy of pavement epithelial cells and vacuolation in the cytoplasm of the chloride cells were observed in the gill. Nanoparticles were also observed in the red blood cells, cytoplasm of all tissues, and glomerulus of the kidney. The observed changes in the serum and tissues may provide useful information regarding environmental conditions and risk assessments of aquatic organisms.

Effects of dietary cottonseed meal level on the growth, hematological indices, liver and gonad histology of juvenile common carp ( Cyprinus carpio )

Abstract Seven isonitrogenous and isoenergetic diets containing cottonseed meal (CM) levels of 0, 9, 18, 27, 36, 45 and 54% (with the free gossypol (FG) levels of 0, 107.8, 215.7, 323.5, 431.3, 539.2 and 647.0 mg kg − 1 , respectively) were fed to juvenile common carp ( Cyprinus carpio ) with initial body weight of 11.3 g for 8 weeks to evaluate the effects of dietary CM on growth performance, hematological indices, liver and gonad histology. When the dietary CM level ranged from 0% to 27%, the weight gain (WG) and feed conversion ratio (FCR) showed no significant difference among groups ( P > 0.05), but when the CM level increased from 27% to 54%, the WG and protein efficiency ratio (PER) significantly decreased ( P P P P P > 0.05). Compared with the groups of 0% and 27% CM, the hepatocyte volume decreased, and the number of hepatocytes increased in the group of 54% CM, which also demonstrated the higher number of primary spermatocytes and the fewer sperm cells in the testis. Taken together, these results indicated that a safe level of CM in the juvenile carp diet was 27% (FG of 323.5 mg kg − 1 ) and broken-line model analysis based on WG showed the upper level of CM was 26.85%. The dietary cottonseed meals higher than 36% (431.3 mg kg − 1 FG) may damage growth performance and hematology. Furthermore, high levels of dietary CM (54% CM with FG of 647.0 mg kg − 1 ) may slightly impair the liver and decrease the number of sperm cells.

Effects of atrazine and chlorpyrifos on cytochrome P450 in common carp liver

Atrazine (ATR) and chlorpyrifos (CPF), widely used in agriculture, have resulted in a series of toxicological and environmental problems. We investigated the activities of the biotransformation enzymes ethoxyresorufin-O-deethylase (EROD) and pentoxyresorufin-O-deethylase (PROD), total cytochrome P450 (CYP), CYP1A mRNA level and level of tissue ATR, CPF, and their metabolites in the liver of common carp (Cyprinus carpio L.) after a 40-d exposure to CPF and ATR, alone or in combination, and a 20-d recovery. In the present study, juvenile common carp was exposed to ATR (at concentrations of 4.28, 42.8 and 428μgL−1), CPF (1.16, 11.6 and 116μgL−1), and ATR/CPF mixture (at concentrations of 1.13, 11.3 and 113μgL−1). A general increasing trend for the activity of the biotransformation enzymes (EROD and PROD), CYP and CYP1A mRNA level was observed in the liver of common carp exposed to ATR, CPF and the ATR/CPF mixture. In addition, ATR, CPF, and their metabolites demonstrated a high accumulation in the liver. These results demonstrated that the CYP system in fish could be used as a biomarkers in evaluating the impact of ATR and CPF exposure on the common carp.

Effect of prochloraz fungicide on neopterin and biopterin concentrations in blood plasma of common carp

Neopterin and biopterin are often used as markers of cell mediated immunity. The aim of this study was to evaluate the effect of prochloraz on neopterin and biopterin concentrations in blood plasma of common carp as possible indicators for monitoring perturbations of the immune system caused by xenobiotics like pesticides. Prochloraz is a widely used imidazole fungicide in horticulture and agriculture. A total of 60 juvenile common carp were divided into four groups of 15 fish and exposed to prochloraz at concentrations of 0, 50, 150 and 380 µg·l-1, respectively. The total length of exposure was 28 days. Neopterin and biopterin concentrations were determined by reverse phase high performance liquid chromatography with fluorescence detection. Our results indicated that concentrations of neopterin (25 ± 7.6 nmol·l-1) and biopterin (190 ± 29 nmol·l-1) in plasma of untreated common carp were comparable with those in mammals. Neopterin concentrations significantly (P < 0.01) increased after exposure to prochloraz in comparison to non-exposed fish, while biopterin concentrations were not influenced by exposure to prochloraz. This study contains new data on neopterin and biopterin concentrations in fish plasma and investigates neopterin and biopterin in their non-traditional role as markers of cell mediated immunity of fish associated with pesticide exposure.

Efficacy of DNA vaccine encoding koi herpesvirus glycoprotein GP-25in common carp juvenile by immersion

<p class="Default">Koi herpesvirus (KHV) is a herpesvirus that particularly infects and causes mass mortality to koi and common carp. Therefore, the protection of common carp from KHV infection is urgently needed. In this study, we developed an application of DNA vaccine encoding KHV glycoprotein-25 by immersion method to increase survival of common carp against KHV infection. A total of 400 common carp juveniles at 30-day-old were immersed in 1-L water containing 1.3×10<sup>8</sup>CFU/mL of the killed <em>Escherichia coli</em> cells carrying DNA vaccine. Three frequencies and three duration of fish immersion were tested, namely: 1×30 minutes, 1×60 minutes, 1× 90 minutes, 2×90 minutes and 3×90 minutes by interval of 24 hours. Reversetranscription polymerase chain reaction analysis showed that DNA vaccine was successfully expressed in the vaccinated fish. Fish at twenty eight days post vaccination were challenged by injecting 10<sup>-4</sup> mL of KHV per fish. The result showed that vaccination by 1×30 minutes immersion allowed 61% of fish survived, and this was significantly higher (p<0.05) compared to control (without vaccination), but it was similar among vaccination treatments (p>0.05). The relative percent survival of vaccinated fish were also similar among treatments (p>0.05). DNA vaccination has increased fish survival about two fold higher compared to unvaccinated fish control (26.67%). Thus, DNA vaccination was effectively delivered by immersion for 1×30 minutes, and this technique can be useful to level up the resistance of common carp juveniles against KHV infection.</p> <p class="Default">Keywords: DNA vaccine, KHV, glycoprotein, immersion, common carp</p>

Quality evaluation of fermented products of various local agroindustrials by-products: the effect on digestibility and growth performance of common carp juvenile

<p>The aim of this research was evaluating the quality and digestibility of fermented local feedstuff as well as its effect on growth performance of common carp <em>Cyprinus carpio </em>juvenile. The local feedstuffs tested in this experiment were kapok seed, cassava peel, copra, rubber seed, and palm kernel meal. The previously milled feedstuff was fermented with instant yeast <em>Saccharomyces cerevisiae</em> with a dose of 0.9% w/w and incubated for 24 hours. Following this, the fermented feedstuffs were dried, mixed with reference diet with a ratio of 3:7 and supplemented with 0.5% Cr<sub>2</sub>O<sub>3</sub> as digestibility test indicator. Common carp juveniles with an initial average body weight of 14,11±1,28 g were cultured for 30 days. Fish feces were collected since the 6<sup>th</sup> day of culture, and followed by laboratory analyses. The results show that fermentation could increase the crude protein content of feedstuff with a range of 16.85‒31.11%, and decrease crude fiber with a range of 2.45‒31.65% with the exception of copra. Furthermore, fermentation also increased the feed digestibility including protein, energy, and total digestibility by the tested fish, as it is shown that the use of fermented feedstuffs may increase protein digestibility 3.88‒11.73%, 2,21‒10,24%, and 3,63‒72,37%. Finally, it can be concluded that fermentation can increase the digestibility of feed with local ingredients by common carp juvenile.</p> <p> </p> Keywords: fermentation, digestibility, local materials, common carp

Expression of immune system-related genes during ontogeny in experimentally wounded common carp (Cyprinus carpio) larvae and juveniles

We investigated the effect of full-thickness incisional wounding on expression of genes related to the immune system in larvae and juveniles of common carp (Cyprinus carpio). The wounds were inflicted by needle puncture immediately below the anterior part of the dorsal fin on days 7, 14, 28 and 49 after fertilization. We followed the local gene expression 1, 3 and 7days after wounding by removing head and viscera before extracting RNA from the remaining part of the fish, including the wound area. In addition, we visually followed wound healing. Overall the wounds had regenerated to a point where they were microscopically indistinguishable from normal tissue by day 3 post-wounding in all but the juvenile carp wounded on day 49 post-fertilization. In these juveniles the wounded area was still visible even 7days post-wounding. On the transcriptional level a very limited response was observed in the investigated genes as a result of the wounding. HSP70 was downregulated 1 and 3days post-wounding in the smallest larvae. However, HSP70 was differentially expressed at different time-points in a similar manner in wounded and mock-wounded groups, thus suggesting a stress effect of the handling, which may have overshadowed some transcriptional effects of the wounding. MMP-9, TGF-β1 and IgZ1 were slightly but significantly upregulated at few time-points, while no effect of wounding was detected on the expression of IgM, C3, IL-1β and IL-6 family member M17.

Spatiotemporal Variation of Juvenile Common Carp Foraging Patterns as Inferred from Stable Isotope Analysis

AbstractOntogenetic diet shifts from zooplankton to macroinvertebrates represent an important transition for many fishes during early life stages. However, some fishes have plastic feeding habits that allow them to take advantage of abundant prey resources or display diet specialization instead of undergoing distinct diet shifts. In this study, we evaluated ontogenetic changes in energy sources (based on the carbon isotope signature, δ13C) and trophic position (based on the nitrogen isotope signature, δ15N) for age‐0 Common Carp Cyprinus carpio from eight natural lakes in eastern South Dakota. In general, Common Carp trophic position decreased and energy sources shifted from pelagic to littoral prey resources from July to August. As anticipated, substantial inter‐ and intrapopulation variation existed in Common Carp isotope signatures. Common Carp trophic position increased with increasing fish TL in three lakes but decreased with fish TL in two systems. Intrapopulation variation in trophic position was related to Common Carp relative abundance during July, indicating that individuals may have specialized on different energy resources as a result of intraspecific interactions. The δ13C values decreased with increasing fish size in two populations during July, suggesting a shift toward pelagic resources; δ13C increased with fish size in six populations during August, suggesting a shift toward littoral resources. Our results indicate a high degree of trophic variation in juvenile Common Carp populations, indicative of a foraging generalist. Year‐class strength may increase trophic specialization of individuals but without negative effects on fish growth, suggesting that diet plasticity is an important factor contributing to the success of this invasive species.

The effect of prolonged exercise training on swimming performance and the underlying biochemical mechanisms in juvenile common carp (Cyprinus carpio)

To investigate the effect of prolonged exercise training on swimming performance and the underlying biochemical mechanisms in juvenile common carp (Cyprinus carpio), we measured the critical swimming speed (Ucrit), the excess post-exercise oxygen consumption (EPOC), the activity of red and white muscle enzymes [pyruvate kinase (PK), lactate dehydrogenase (LDH) and citrate synthase (CS)], the tissue substrates (glycogen and glucose content of muscle and liver) and metabolite (the lactate content of plasma and muscle) content of exercise-trained (60% Ucrit for 4weeks) and non-trained fish. We also measured the biochemical indices of both trained and non-trained fish immediately after Ucrit, after exhaustive exercise and 1h after exhaustive exercise. The aerobic swimming performance, as indicated by Ucrit, increased significantly after exercise training, most likely because of the higher tissue metabolic capacity, as suggested by the higher CS activity in the red muscle tissue, and the higher energy store and more efficient substrate utilization, as suggested by higher liver and muscle glycogen contents at rest but lower tissue glycogen contents after Ucrit. The lower lactate content after Ucrit is most likely because of higher aerobic metabolic capacity, and (or) the clearance rate of lactate in trained fish may also contribute to improved aerobic swimming performance. Compared to Ucrit, exhaustive exercise elicited higher plasma and muscle lactate contents. The anaerobic metabolic performance is not affected by the exercise training, as suggested by the EPOC. However, trained fish did show higher lactate clearance rates, as suggested by lower muscle lactate content after a 1h recovery period following exhaustive exercise compared to non-trained fish. Furthermore, trained fish decreased their liver and muscle glycogen contents more profoundly after exhaustive exercise, suggesting that training can improve the substrate utilization during anaerobic exercise.

Eugenol e benzocaína como anestésicos para juvenis de Cyprinus carpio Linnaeus, 1758 (carpa comum)

Anesthetics such as benzocaine and eugenol are efficiently used in fish to reduce stress both in the management of animals as for transport and reproduction. The aim of this study was to evaluate the induction times and recovery of juvenile common carp ( Cyprinius carpio ) exposed to both anesthetics, benzocaine (12,5; 25; 37,5; 50; 62,5; 75; 87,5; 100 e 112,5 mg L -1 ) and eugenol (12,5; 25; 37,5; 50; 62,5; 75 e 87,5 mg L -1 ). Hundred and thirty six juveniles were used with a mean weight of 1.92 ± 0.59 g and mean total length of 5.25 ± 0.52 cm. The benzocaine proved more efficient than eugenol over time, thus to induce coma as to recover the scape and also with regard to survival. The doses of benzocaine with best results were 87.5 and 100 mg L -1 . Eugenol delay resulted in the induction and recovery of the animals, and also presented anesthetic mortality when doses were increased.

Osteological and histopathological details of unilateral microphthalmia and anophthalmia in juvenile common carp (Cyprinus carpio)

We describe and compare normal eye, unilateral microphthalmia (small eye), and unilateral anophthalmia (eye incompletely developed) in young (5–7month-old) common carp, Cyprinus carpio, (Cypriniformes: Cyprinidae). Five of 1058 (0.47%) common carp had grossly-observed eye deformities that we characterized using osteology and histopathology: 2 (81 and 98mm fork length) had unilateral microphthalmia and 3 (103, 123, and 137mm in fork length) had unilateral anophthalmia. Grossly, the eye of the microphthalmic common carp was opaque and slightly protruding from a reduced orbit; whereas, only a slight integumental concavity was observed on the deformed side of the anophthalmic common carp. Osteologically, microphthalmic and anophthalmic common carp had an irregular orbit with orbital bones that were laterally-expanded and that formed a discontinuous, uneven orbital perimeter compared to the narrow orbital bones forming a nearly circular orbit in normal common carp. Histologically, microphthalmia manifested as an eye having a thickened cornea with a retina and attached optic nerve but no lens (aphakia); whereas, anophthalmia manifested as lacking a globe, cornea, lens, or retina but having a nerve fascicle and capillaries representing probable optic nerve and its associated choroid. No histological sign of infection was observed in the ocular region of any common carp studied. The etiological agent associated with microphthalmia and anophthalmia is indeterminate, and the hypothesis that electroporation caused the ocular deformity was not tested herein. We suspect that the microphthalmic eye could detect light but not form a focused image. A list of putatively similar abnormalities in other fishes as well as anisophthalmia (incomplete eye development) and symmetrical cyclopia (medially fused eye) in larval and juvenile fishes is provided. This is the first published report providing osteological or histopathological details of microphthalmia or anophthalmia in a non-embryonic or non-larval fish.

Hematological and biochemical responses of common carp Cyprinus carpio to direct infusion of crude oil

Crude oil is one of the dangerous pollutants within water ecosystems. The purpose of current research was to determine the controlled effects of LC50–96h dose (22.4 ± 0.03 ppm) of crude oil for 0, 24, 48, and 96 h on hematological and biochemical indices of juvenile common carp. Results showed significant elevation in the white blood cell (WBC) and red blood cell (RBC; P < 0.01). Exposure to crude oil significantly increased hemoglobin and hematocrite (P < 0.01). Among RBC indices, only mean corpuscular hemoglobin concentration was not significantly different and both mean corpuscular volume and mean cell hemoglobin showed significant elevation after exposure (P < 0.01). Just neutrophil and lymphocyte were found within WBC indices and both of them significantly changed (P < 0.01). Among biochemical indices, in contrast to glucose, cortisol significantly elevated.