Nephroblastoma in a Koi (Cyprinus carpio)

A cachexic 2-year-old koi (Cyprinus carpio) presented with progressive distension of the coelom (1-month period) and anorexia of 2 days' duration. The fish had been maintaining a normal swimming position, although it was often observed low in the water column. Water quality was within normal limits. A skin scrape, fin clip, and gill clip were unremarkable. The respiration rate (opercular movement) was elevated at 100 breaths per minute. Blood chemistry values demonstrated a hypoalbuminemia (1.3 g/dL), elevated uric acid (1.3 mg/dL), elevated creatine kinase (>14,000 U/L), and hyperkalemia (3.9 mmol/L). Ultrasound revealed a fluid-filled coelom and a soft tissue mass containing large vessels filling most of the coelomic cavity. Fine-needle aspirates of the mass were nondiagnostic, though a poorly exfoliating mesenchymal tumor was suspected. The mass was surgically excised. Pathological examination of the mass revealed it to be a poorly demarcated and unencapsulated neoplasm forming 3 histological patterns in which a spindle cell stromal component predominated over an intermediate-sized blastema and much smaller tubular patterns. These features were most consistent with a nephroblastoma. The koi survived 5 days postoperatively but remained low in the water column and was found dead on day 6. A full necropsy of this patient was not performed.     

Fish and antibiotics: pharmacokinetics of sulphadimidine in carp (Cyprinus carpio)

Pharmacokinetics, metabolism and clearance of sulphadimidine (SDM) were studied after a single intraperitoneal injection of SDM in carp at 20 degrees C. SDM was acetylated and hydroxylated to a small extent. The main metabolite was N4-acetyl derivative amounting only 2% of the total drug dose excreted; hydroxylation was less important (0.41% of the dose). The elimination half-life for SDM in carp was 17.5 h. The clearance values for SDM and its metabolites were equivalent. The importance of pharmacokinetic studies in different fish species is discussed.     

Differences between the European carp (Cyprinus carpio carpio) and the coloured carp (Cyprinus carpio haematopterus) in susceptibility to Thelohanellus nikolskii (Myxosporea) infection

Thelohanellus nikolskii infection of the common carp (Cyprinus carpio L.) has been a common parasitosis in the Central European fish farms since the first detection of the parasite about 20 years ago. This parasite, introduced from the Far East, causes intensive infection on the fins of fingerlings of the carp subspecies cultured in Europe (European carp, Cyprinus carpio carpio). This infection of the common carp occurs in the Hungarian fish farms every year. Until the present study, this parasite had not been recorded from the fins of koi or coloured carp (Cyprinus carpio haematopterus), a carp of Far Eastern origin, which is cultured in Hungary as an ornamental fish. A recent survey conducted in common carp, koi and goldfish stocks demonstrated that T. nikolskii infection of low prevalence and intensity occurs also in koi populations, but its prevalence and intensity are markedly lower than in common carp kept in the same ponds. It is suggested that the observed differences are due to disparities in the susceptibility of the two carp subspecies to T. nikolskii, and that the koi is less susceptible to this infection. Other signs of susceptibility can also be observed in the European subspecies, since in 15% of the fish plasmodium development was arrested at an early stage. Thelohanellus nikolskii infection could not be demonstrated on goldfish (Carassius auratus).     

Physiologic and biochemical measurements and response to noxious stimulation at various concentrations of MS‐222 in Koi (Cyprinus carpio)

ObjectiveTo evaluate the physiological effect and response to noxious stimulation at five concentrations of MS-222 in koi (Cyprinus carpio).Study designProspective experimental study.AnimalsTwenty-one healthy adult unknown sex koi fish weighing mean 450 ± SD 120 g.MethodsEach fish was exposed to five different concentrations of MS-222 (50, 70, 110, 150 and 190 mg L^?1) in a random sequence during the same anaesthetic event. For each concentration of MS-222, vital functions such as heart rate (HR) (via Doppler) and opercular rate (OpR) were recorded after a standardized induction period. Response to two noxious stimuli in the form of haemostat clamp pressure applied on the tail and the lip was evaluated, and blood was drawn to measure biochemical and blood gas values.ResultsDecrease in response to noxious stimulation with an increase of MS-222 concentration both for the lip (p = 0.0027) and the tail (p < 0.0001) stimulus was observed. Biochemical values were unaffected by the concentration of MS-222 with the exception of lactate concentration which was weakly correlated with the duration of anaesthesia (r = 0.31, p < 0.001) and the number of times the fish was clamped or bled prior to sampling (r = 0.23, p < 0.001). Opercular rate decreased with the increase in anaesthetic concentration, and HR was not affected.Conclusions and clinical relevanceOur results indicated a decrease in response to stimulus and a decrease in OpR that were associated with increased concentrations of MS-222. This may assist in establishing anaesthetic protocols using MS-222 in fish and supports the use of supramaximal pressure stimuli to teleost fish under variable MS-222 concentrations as a model for future studies.     

Stabilisation of scoliosis in two koi (Cyprinus carpio)

Two koi (Cyprinus carpio) from the same pond developed similar lesions of scoliosis. Radiographic examinations showed that their spines had become malaligned as a result of vertebral compression fractures involving T14 to T16. The vertebrae in both fish were stabilised with screws, k-wire and polymethylmethacrylate. They both appeared to improve after surgery, but they began to decline and died within three months. A postmortem examination revealed multi-organ inflammation that was not associated with the surgical implants.     

Epitheliocystis in carp (Cyprinus carpio) in South Korea

Epitheliocystis in the carp of a pet fish market were investigated by our diagnostic work and collecting information from department of laboratory animal medicine and fish & shellfish laboratory. The epitheliocystis was identified by using histopathological examination. Epitheliocystis was confirmed as inflammation, epithelial hyperplasia, and lamellar fusion of the gill tissue. Electron microscopic observation showed that the inclusions were filled with Chlamydia-like organism.     

Mechanism of blood coagulation in common carp (Cyprinus carpio)

In vitro, carp blood was anticoagulated by using MgSO₄ at a final concentration of 22.2 mmol L^?1 and sodium citrate at a final concentration of 11.8 mmol L^?1. The coagulation times for carp plasma diluted by ion‐free water (1:1), and that of carp plasma to which thrombocytes and small lymphocytes were added, were measured at 23 °C using standard methods, and then contrasted with the coagulation times for plasma obtained from chickens and rabbits. The shapes of the thrombocytes and small lymphocytes, which were either wet mounted or stained with hematoxylin and eosin, were observed under a light microscope. We found that: (i) the coagulation reaction of carp blood was significantly (P < 0.01) accelerated by the addition of ion‐free water; (ii) the three types of blood cells (thrombocytes, small lymphocytes and red blood cells) promoted plasma coagulation to a similar extent (P > 0.05); (iii) in carp Mg²⁺ plasma and K₂C₂O₄ plasma, the thrombocytes were usually morphologically normal, but many small lymphocytes were destroyed and became aggregated; (iv) in the citrate plasma, thrombocytes were often aggregated, but the small lymphocytes were usually morphologically normal; and (v) the coagulation time for chicken and rabbit plasma was significantly extended by adding ion‐free water.     

Pox-like lesions in a colony of carp (Cyprinus carpio)

Twelve carp (Cyprinus carpio) out of a total of 100 were affected with skin nodules, mainly located on the dorsal and lateral surface. Post mortem examination of six of the worst affected fish showed the nodules consisting of white gel-like outgrowths. No abnormality was apparent in any other tissue examined. Microscopically, the nodules were formed by proliferating hyperplastic epidermal cells. The other six fish were left for recovery and their nodules regressed spontaneously. The possible aetiological factors are listed.     

The efficacy of alfaxalone for immersion anesthesia in koi carp (Cyprinus carpio)

ObjectiveTo characterize the physiologic and behavioral effects of a single induction dose and two maintenance doses of alfaxalone delivered by water immersion in the anesthesia of koi (Cyprinus carpio).Study designProspective, within-subject complete crossover design.AnimalsSix adult koi (Cyprinus carpio) with a median body weight of 344.5 g (range 292.0–405.0 g).MethodsKoi were immersed in water containing 10 mg L^?1 alfaxalone until immobile and then maintained with alfaxalone at either 1 or 2.5 mg L^?1 via a recirculating water system. Times for anesthetic induction and recovery periods were recorded. Physiologic and blood gas parameters were evaluated before, during and after the anesthetic trial. Response to noxious stimuli was also assessed.ResultsMedian anesthesia induction time for all fish was 5.4 minutes. Median recovery time was 11.8 and 26.4 minutes in the 1.0 and 2.5 mg L^?1 doses, respectively, which were significantly different (p = 0.04). Cessation of opercular movement occurred in 0/6 and 4/6 fish exposed to 1.0 and 2.5 mg L^?1 dose respectively. No difference was observed in median heart rate over the duration of the anesthetic events. Response to noxious stimulation was 4/6 and 0/6 in the 1.0 and 2.5 mg L^?1 doses respectively. Oxygenation and ventilation did not change during the experiment, but there was a significant decrease in blood pH along with an increase in blood lactate concentration.Conclusion and clinical relevanceAdministration of alfaxalone, via water immersion, as an induction and maintenance anesthesia agent provided rapid and reliable anesthesia of koi with no mortality. The maintenance dose of 2.5 mg L^?1 was sufficient to prevent response to noxious stimuli but was associated with a clinically relevant depression in opercular rate.     

益生菌对锦鲤幼鱼生长性能及血液、肝脏和肠道组织中相关免疫基因表达的影响

为研究饲料中添加益生菌对锦鲤幼鱼生长性能和相关免疫基因表达的影响,以初始体重为248.13±4.71 g的锦鲤幼鱼为研究对象,在小型循环水养殖池进行60 d的养殖试验.对照组投喂无益生菌添加的普通商品饲料,试验组投喂在普通饲料中添加枯草芽孢杆菌(Bacillus subtilis)、丁酸梭菌(Clostridi-um ...     

Evaluation of Emamectin Benzoate for the Control of Experimentally Induced Infestations of Argulus sp. in Goldfish and Koi Carp

Abstract

The effect of 0.2% emamectin benzoate (SLICE; Intervet/ Schering-Plough Animal Health, Roseland, New Jersey) administered in top-dressed, pelleted commercial fish feed was evaluated for control of freshwater Argulus sp. in goldfish Carassius auratus and koi carp, a variant of common carp Cyprinus carpio, in freshwater aquaria at 24–25°C. Sixteen individually housed goldfish were each exposed to 37 Argulus. The number of fish lice attached to each fish at the start of the experiment was not determined; however, the total number of motile fish lice in each aquarium (on fish and in the water) was determined at the start and end of each experiment. Eight goldfish were fed the control diet (0 μg · kg fish biomass^?1 · d^?1) and eight were fed the medicated diet (50 μg · kg fish biomass^?1 · d^?1) for seven consecutive days. After treatment, fish louse infestation in controls was 20.5 ± 1.5 (mean ± SE) lice per fish. No Argulus were found on fish in the treated group. In a separate experiment, 10 individually housed koi were each exposed to 128 Argulus. Five koi were fed the control diet and five were fed a low-dose medicated diet (5 μg · kg fish biomass^?1 · d^?1) for 7 d. After treatment, fish louse infestation among the controls was 14.6 ± 3.8 lice per koi. No Argulus were found on koi in the treated group. Hence, a 7-d regimen of oral emamectin benzoate controlled experimental infestation of Argulus when administered to goldfish at 50 μg · kg fish biomass^?1 · d^?1 and to koi at 5 μg · kg fish biomass^?1 · d^?1.

Received March 24, 2010; accepted January 17, 2011     

氧化鱼油对鲤鱼(Cyprinus carpio)肉质的影响

本试验在饲料中添加2%的新鲜鱼油(其过氧化物值(POV)1.28meqO2/kg)和POV(meqO2/kg)分别为118.79、189.37和367.86的氧化鱼油,并在新鲜鱼油和POV为118.79meqO2/kg的氧化鱼油饲料中分别添加VE100mg/kg,形成6个处理饲料,投喂50±3g1龄鲤鱼鱼种两个月,结果表明:1氧化鱼油消耗鲤鱼肌肉中VE(P<0.05),消耗程度与鱼油氧化程度成正比关系。随着储存(-20℃)时间延长,VE含量明显下降(P<0.05);2新鲜鱼油和POV为118.79meqO2/kg的氧化鱼油对鲤鱼肌肉储存(-20℃)期间氧化稳定性的破坏作用强于POV(meqO2/kg)为189.37和367.86氧化程度较高的鱼油,但新鲜鱼油的破坏作用低于POV为118.79meqO2/kg的低氧化程度鱼油。肌肉氧化稳定性在储存初期较差,15d时增强,之后随时间延长而下降;3氧化鱼油对肌肉挥发性盐基氮(VBN)无显著影响(P>0.05),而储存(-20℃)时间对肌肉VBN有显著影响(P<0.05);4氧化鱼油显著增加肌肉渗出性损失(P<0.05),但随着鱼油氧化程度升高,增加态势相对减弱(P>0.05)。随着解冻时间延长肌肉渗出性损失增加(P<0.05);5饲料中添加VE相应提高肌肉中VE水平(P<0.05)、减弱氧化鱼油对肌肉氧化稳定性的破坏(P<0.05)、减少肌肉VBN生成(P<0.05)和降低氧化鱼油诱发的肌肉渗出性损失(P>0.05)。     

Reproductive medicine in koi (Cyprinus carpio).

Each year more veterinarians are seeing ornamental fish patients and our knowledge of how to manage the pet fish patient is increasing at a rapid pace. A large percentage of these patients are nishikigoi (Cyprinus carpio) which are taxonomically an ornamental carp. In this country and in many parts of the world we refer to these fish as koi. Reproductive medicine problems are well documented in koi and a thorough knowledge of this subject will aid the fish practitioner in diagnosis and treatment.     

裳卷蛾变形孢虫(Vairimorpha ceraces sp.nov.)对家蚕、鱼类的感染性试验

裳卷蛾变形孢虫(Vairim orpha ceracessp.nov.)对家蚕为敏感性感染,感染中量(IC50)为1.2×104,可广泛寄生各种组织,其中丝腺与马氏管被严重寄生,病蛾胚传率为2.69%,孢子发育形态明显偏向二孢子母细胞(d is-porous)发育。以2×107~4×107粒孢子/mL对每尾红鲤(red carp)添食0.5 mL,饲养40 d后解剖全部鱼体,约有10%~20%的试验鱼出现了明显的组织病变,在寄生组织中观察到大量的梨形未成熟孢子和少量的成熟孢子,但未观察到八孢子囊(octosporous)形态,病变组织疑似孢子免疫荧光检测为阳性,3次独立重复试验均得到了同样的结果,表明高浓度裳卷蛾变形孢虫可能对红鲤发生了机会性感染。试验结果对探讨微孢子虫的感染与感染适应性机制具有重要意义。     

Myxobolus infections of common carp (Cyprinus carpio) in Syrian fish farms

During a survey on Myxobolus infection of pond-cultured common carp in Syria three Myxobolus spp. were found. Myxobolus dispar infected the gill arteries, forming large elongated plasmodia in the gill filaments. The plasmodia of M basilamellaris were located in the gill arches at the base of the filaments. Elongated filiform plasmodia of M. encephalicus were found in the blood vessels of the brain. Despite the common occurrence of the above parasites, no disease symptoms were observed in the infected fish specimens. This is the first report on myxosporean infection of fish from Syrian waters.     

Granulocyte responses to experimental injection of live and formalin-killed bacteria in carp (Cyprinus carpio)

The objective of the study was to investigate the dynamics of changes in number of granulocytes in bacterial infections of carp (Cyprinus carpio). Carp were inoculated with non-pathogenic or pathogenic bacteria and changes in type I (neutrophils) and type II granulocyte (basophils/eosinophils) counts in kidney, circulating blood and peritoneal cavity were assessed. After the injection of non-pathogenic bacteria (Escherichia coli), the number of type I and II cells in blood increased after 6-12h, but returned to the control level after 24-48 h. In contrast, after the injection of pathogenic bacteria (Aeromonas hydrophila), the number of type I cells initially increased followed by an increase in the number of type II cells. The peak counts of type I and II cells were at 12 and 24h after the injection, respectively. When the fish were given serial-injections of formalin-killed bacteria at 12-h intervals, the type II cells also predominantly increased and remained at high levels, following the peak count of type I cells.     

Herpesvirus-associated papillomas in koi carp (Cyprinus carpio).

From January through November 1994, 32% (7/22) of koi carp (Cyprinus carpio) maintained in indoor aquariums developed proliferative cutaneous lesions that consisted of single to multiple 2-10-mm whitish to pink fleshy masses usually associated with fin rays. Although scaleless koi were more commonly affected (3/6) than were normally scaled koi (4/16), the difference in incidence rates was not significant (chi2 text, P > 0.05). Lesions typically resolved spontaneously in 1-3 wk, occasionally persisted for >3 mo, and recurred in several fish after 2-5 mo. Fish were otherwise asymptomatic. Wet mount preparations from lesions were densely cellular and consisted of hyperplastic epidermal cells of normal morphology without parasites or inflammatory cells. Histologically, biopsies were consistent with papillomas and were characterized by a marked benign epidermal hyperplasia without inclusion bodies or inflammatory infiltrate. Transmission electron microscopic examination revealed intranuclear and intracytoplasmic herpesvirus virions. Virus isolation attempts were unsuccessful.     

Fumonisin B1 causes multiple lesions in common carp (Cyprinus carpio)

Year-1 carp were fed ratios containing 100mg/kg and 10 mg/kg of added fumonisin B1 for 42 days. The experimental and control fish were examined clinically during the experiment and at the end all fish were necropsied and histological changes recorded. Blood vessels, liver, exocrine and endocrine pancreas, excretory and haematopoietic kidney, heart and brain were sensitive both to 100 and 10mg/kg of FB1 in the diet and the rodlet cell (RC) frequency was considerably increased in and around damaged tissues. Many damaged blood vessels contained stacks of RCs above the endothelium. Other changes subsequent to fumonisin exposure that have not been previously reported include scattered lesions in the exocrine and endocrine pancreas, and interrenal tissue, probably due to ischemia and/or increased endothelial permeability. Presented findings indicate the need for more intensive studies of fumonisin-induced toxicity in cultured fish.     

Two independent cases of spontaneously occurring branchioblastomas in koi carp (Cyprinus carpio)

This report documents 2 cases of branchioblastomas in koi carp (Cyprinus carpio). Macroscopically, both cases were characterized by well-demarcated, pale red nodular masses located at the left first branchial arch and the right pseudobranch, respectively. Histologically, the neoplasias were composed of blast-like cells that differentiated into cartilage and branchial lamellae embedded in abundant fibrous connective tissue. Based on these findings, a branchioblastoma was diagnosed.