Efficacy of quinine against ichthyophthiriasis in common carp Cyprinus carpio

Ichthyophthiriasis, caused by Ichthyophthirius multifiliis, is an economically important worldwide parasitic disease that infects all freshwater fish. Since the banning of malachite green for use in food fish, there has been a great need for alternative therapeutants. The goal of this study was to investigate the efficacy of quinine against I. multifiliis. Parasite developmental stages from our laboratory-established life cycle in rainbow trout Oncorhynchus mykiss were exposed to quinine in vitro, and a dual fluorescent staining technique was used to allow a clear distinction between viable and damaged parasites. Furthermore, the effect of quinine was assessed in vivo by oral administration and intraperitoneal injections in common carp Cyprinus carpio. The results of the in vitro experiments proved quinine to be effective against the parasite. Quinine injected at a dosage of 60 mg kg(-1) body weight resulted in a significantly lower number of trophonts. In contrast, in-feed trials did not show a significant reduction of trophonts after treatment commencing 1 d after infection with concentrations of up to 20 g quinine kg(-1) feed for 3 d. After a 14-d treatment at concentrations of up to 10 g quinine kg(-1) feed prior to theront exposure, there was also no significant difference in parasite numbers between treated and control groups. The results of oral versus parenteral application of quinine indicate that the substance is not completely absorbed from the intestinal tract of common carp. However, medicated feed containing higher concentrations of quinine was less readily accepted by the fish, presumably due to the bitter taste.     

Effects of common carp (Cyprinus carpio) on macrophytes and invertebrate communities in a shallow lake

1. We performed two field experiments using different cage sizes to determine the direct and indirect effects of carp on macrophytes and invertebrate community composition in a shallow lake. 2. The presence of carp produced a significant decrease in macrophyte abundance, changes in species composition and decreased abundance and diversity of invertebrates in small (2.5 × 2.5 × 2.0 m) cages. In large exclosures (15 × 5 m), only macrophyte stem length was significantly affected by carp. 3. There was considerable variation in the macrophyte and invertebrate responses to carp on different sides of the lake in the large exclosures, suggesting that wind and wave action are also important variables affecting macrophyte growth and persistence. 4. The data suggest that carp can significantly affect species abundance and diversity of macrophytes and some macroinvertebrates.     

Microsatellite markers in common carp (Cyprinus carpio L.)

Microsatellite markers of the poly (CA) type in common carp ( Cyprinus carpio L.) are described. Clones containing a (CA) repeat were isolated from a common carp genomic library and sequenced. The number of repeats found was high compared to mammals but comparable with other teleost fishes. Classification of the repeats (perfect, imperfect and compound) are compared with the Atlantic cod ( Gadus morhua L.), rainbow trout ( Oncorhynchus mykiss ), and Atlantic salmon ( Salmo salar L.). A total of 41 primer sets were designed and tested for polymorphism on a test panel of eight animals (derived from outbred lines, inbred lines and gynogenetic clones). Thirty-two markers were found to be polymorphic. The heterozygosity in the outbred animals was 60·4%, 51·1% in the inbred animals and 0% in the gynogenetic clones. The average number of alleles among the eight animals was 4·7 per marker. Six markers (18·8%) gave an additional polymorphic amplification product besides the polymorphic amplification product in the expected size range. The possibility that these loci are tetraploid is discussed. The polymorphic loci described for common carp will be valuable as genetic markers for use in population, breeding, and evolutionary studies.     

Cadmium-binding to transferrin in the plasma of the common carp Cyprinus carpio

In this study, it was investigated by autoradiography with radioactive cadmium after Western blotting of two-dimensional electrophoresis gels, to which proteins cadmium is mainly bound in plasma of common carp Cyprinus carpio. The obtained results demonstrate that in carp plasma, cadmium is primarily bound to two high molecular weight proteins. Relative small amounts are bound to a protein with M(r) approximately 60000. The other metal-binding protein, with M(r) approximately 70000 and pI approximately 6.7 was identified as transferrin. The conditional equilibrium constants for the binding of cadmium ions to the two metal-binding sites of this protein were calculated as logK(1)=5.40+/-0.12 and logK(2)=4.66+/-0.21, which are comparable to those of human transferrin under the same experimental conditions. Transport of cadmium in plasma of carp was found to be different from that of brown trout Salmo trutta and man, where cadmium is mainly bound to albumin and transferrin. The prominent binding of cadmium to transferrin can be explained by the absence or at least the very low concentrations in which albumin is present in carp plasma.     

Genetic evolution and diversity of common carp Cyprinus carpio L.

Knowledge of genetic variation and population structure of existing strains of both farmed and wild common carp Cyprinus carpio L. is absolutely necessary for any efficient fish management and/or conservation program. To assess genetic diversity in common carp populations, a variety of molecular markers were analyzed. Of those, microsatellites and mitochondrial DNA were most frequently used in the analysis of genetic diversity and genome evolution of common carp. Using microsatellites showed that the genome evolution in common carp exhibited two waves of rearrangements: one whole-genome duplication (12–16 million years ago) and a more recent wave of segmental duplications occurring between 2.3 and 6.8 million years ago. The genome duplication event has resulted in tetraploidy since the common carp currently harbors a substantial portion of duplicated loci in its genome and twice the number of chromosomes (n = 100–104) of most other cyprinid fishes. The variation in domesticated carp populations is significantly less than that in wild populations, which probably arises from the loss of variation due to founder effects and genetic drift. Genetic differentiation between the European carp C.c. carpio and Asian carp C.c. haematopterus is clearly evident. In Asia, two carp subspecies, C.c. haematopterus and C.c. varidivlaceus, seem to be also genetically distinct.     

Ultrastructural identification of a herpes-like virus infection in common carp Cyprinus carpio in Korea

We report on a herpes-like virus, which was found to be associated with mass mortality of common carp Cyprinus carpio for the first time in Korea in 1998. The external signs of infection in moribund fish were darkened coloration and severe branchial necrosis in the gill. Transmission electron microscopy revealed the presence of herpes-like viruses in spleen tissue. Infected spleen cells showed hypertrophied nuclei and degeneration. Numerous nucleocapsids of about 82 nm in diameter were found within the nucleus and cytoplasm of infected cells, and extracellular enveloped particles were also observed. We conclude that this virus was a likely significant cause of the high mortality of common carp in Korea in 1998.     

Predicting muscle force generation during fast-starts for the common carp Cyprinus carpio

Muscle contractile properties have been characterised for white myotomal muscle from the common carp Cyprinus carpio at 10, 15, and 20 °C. The time course of muscle force development was measured when one, two, or three stimuli were delivered at the onset of constant velocity shortening. As the shortening velocity increased several parameters decreased including the maximum force, the time course for the contraction and the relative duration of the deactivation compared to the activation. The maximum force and the relative rates of activation to deactivation for the contraction were relatively independent of temperature, whereas the duration of the contraction decreased with increasing temperature. A predictive model was developed which was based on fitting a modified Weibull distribution to these observations. The model was used to interpolate the expected contractile forces during cyclic length-changes. Measured and predicted values for force and power during such cyclic work-loop experiments showed an excellent agreement over the range of shortening regimes typically found during swimming behaviours. However, the predicted force was overestimated during the deactivation phase of the contractions when the shortening velocities exceeded those found during swimming. Accepted: 25 May 1999     

Study on a prolyl endopeptidase from the skeletal muscle of common carp (Cyprinus carpio)

A prolyl endopeptidase (PEP) was purified to homogeneity from the skeletal muscle of common carp using a procedure involving ammonium sulfate fractionation and column chromatography involving DEAE-Sephacel, Phenyl-Sepharose, DEAE-Sepharose Fast Flow, and hydroxyapatite. The molecular weight of the PEP was 82 kDa as determined by SDS-PAGE. Using Suc-Gly-Pro-MCA as a substrate, the optimal pH and temperature of the purified enzyme were pH 6.0 and 35 °C, respectively, and the K_m and k_cat were 8.33 μM and 1.71 S^?1, respectively. The activity of the PEP was inhibited by SUAM-14746, a specific inhibitor of prolyl endopeptidases, and was partially inhibited by the serine proteinase inhibitors PMSF and Pefabloc SC. According to peptide mass fingerprinting, 12 peptide fragments with a total of 134 amino acid residues were obtained, which were highly identical to prolyl endopeptidases from zebrafish (Danio rerio) and sponge (Amphimedon queenslandica), confirming the purified enzyme was a prolyl endopeptidase. Our present study for the first time reported the existence of a prolyl endopeptidase in fish muscle.     

The effect of digested sludge on the common carp, Cyprinus carpio L.

The effects of sewage sludge on the survival of the common carp, Cyprinus carpio, were investigated. It was noted that, when the concentrations of the sludge used for rearing carp exceeded 0.6%, the fish died within 42 days, whereas those reared in 0.2% sludge remained alive and healthy during the trial period. The body and the gills of the dead fish were covered by a veil-like film which looked like coagulated mucus and was formed by the heavy metal ions from the sludge reacting with some constituents of the mucus secreted by the gill. The histopathological symptoms of the various organs further demonstrated that internal injury in liver and kidney was also an important feature of the intoxicants as well as external damage, especially the particles observed around the gills. It was concluded that the optimum concentration of sludge to any species of fish should be determined by testing a series of concentrations before using it as a supplementary fish feed or fish pond fertilizer.     

Determination of the surface area of common carp,Cyprinus carpio L.

A wrap method adaptation combined with AutoCAD2005 and Scion Image for Windows were used to determine the surface area of a fish. Compared with the corresponding r² and F of many models, the most accurate formula: S = 752.15W^0.675 (r² = 0.999, F = 18362.94, P < 0.0001) for estimating the surface area of common carp was obtained. Similarly, the fin formula: S = 1834.12W^0.708 (r² = 0.992, F = 2690.47, P < 0.0001) was also obtained for the same purpose. It was proven that these two formulae gave good estimates of surface and fin areas of four strains of common carp: Yellow‐river carp, fancy carp, mirror carp and Xingguo red carp.     

Regulation of AMP-deaminase activity from white muscle of common carp Cyprinus carpio

AMP-deaminase was purified to electrophoretic homogeneity from white skeletal muscle of a teleost fish, the common carp, Cyprinus carpio. The purified enzyme was highly stable and showed non-Michaelis-Menten kinetics with a S(0.5) value for AMP of 2.52+/-0.16 mM (SEM) and a Hill coefficient of 1.19+/-0.11. Specific activity of the purified enzyme was 1000-1200 U/mg protein. The pH optimum was 6.3 and the enzyme was activated by ADP and ATP, but inhibited by phosphate and fluoride. Low concentrations of NaCl and KCl (100-150 mM) activated, whereas higher concentrations were inhibitory. Free radicals inactivated the enzyme, decreasing V(max) by one-half but not affecting S(0.5) or Hill coefficient. Possible regulatory mechanisms of AMP-deaminase activity in fish muscle are discussed.     

The ingestion of bacteria in suspension by the common carp Cyprinus carpio L.

Groups of large (65 -75 g) and small (8-17 g) common carp ( Cyprinus carpio L.) fingerlings were exposed to the bacterium Chromobacterium violaceurn in order to establish whether they could detect and ingest unattached bacteria. Small fish exposed to both bacteria and to cell-free bacterial extracts showed a significant increase in opercular beat rates, thus demonstrating that they are able to detect the presence of unattached bacteria in suspension. Examination of carp gut contents showed that the proportion of small fish ingesting bacteria increased with exposure time although no significant relationship was observed among larger fish. Significant, positive correlations between numbers of viable bacteria isolated from the intestinal tracts and concentration in the environment were observed. Possible mechanisms of bacterial ingestion are discussed.     

Physiological compartmentation in gonadal tissue of the common carp (Cyprinus carpio L.)

Summary Physiological compartmentation in carp (Cyprinus carpio L.) gonads was investigated after intracardial injection of horseradish peroxidase (HRP) and two mouse anti-carp-sperm monoclonal antibodies.Immunohistochemistry revealed that a physiological barrier exists in carp testis for HRP and mouse IgG monoclonal antibody around the central lumina of the tubules in which the spermatozoa are located, but not around the cysts containing the precursor germ cells. The results with HRP were confirmed by electron microscopy. Mouse IgM monoclonal antibody did not penetrate the spermatogenic cysts. Probably because of its large size, it was almost exclusively located inside blood capillaries and only sparsely in the interstitial tissue.In the ovary, HRP was regularly distributed in the gonadal tissue, whereas the IgG antibody was predominantly localised on oogonia and early prophase oocytes. The results indicate that in contrast with the testis, no barrier around germ cells exists in the carp ovary.     

Monoclonal antibodies against spermatozoa of the common carp (Cyprinus carpio L.)

Summary Eleven monoclonal antibodies that recognize membrane determinants on spermatozoa of the carp Cyprinus carpio L. have been produced. Indirect immunofluorescence revealed that these determinants are uniformly distributed on the surface of head and midpiece. Most of them are also present on the outer membrane of precursor sperm cells. Although none of the monoclonal antibodies reacted with carp somatic tissue, five monoclonal antibodies were positive for surface membrane determinants of oogonia and early prophase oocytes in carp ovary. Preliminary analysis of the testis and ovary of three other species of fish showed that some carp determinants are shared with germ cells from Barbus conchonius, Clarias lazera, or Salmo gairdneri.Abbreviation WCS Wageningen Carp Sperm antibody     

The biomechanics and evolutionary significance of thermal acclimation in the common carp Cyprinus carpio

The effects of thermal acclimation were investigated in the common carp Cyprinus carpio L. Acclimation and acute temperature effects were tested during ontogeny from larval [9.5 mm total length (L)] to juvenile (69.0 mm L) stages and between 8 and 21 degrees C. The myosin heavy chain (MHC) composition, myofibrillar Mg(2+)-Ca(2+)-ATPase activity, and muscle strains showed significant thermal acclimation effects. MHCs were only expressed in an acclimation temperature-dependent fashion in fish longer than 37 mm. During fast starts, the temperature had a significant effect on the white muscle strain (33% increase and 50% decrease with increasing acclimation and acute temperature, respectively) and contraction duration (25% decrease with increasing acute temperature). Increases in hydrodynamic efficiency (0.19 to 0.38) and hydrodynamic power requirements (Q(10) = 3.2) occurred with increasing acute temperature (10 to 20 degrees C). Competing hypotheses about the evolutionary significance of the temperature acclimation response were tested. Acclimation extended the temperature range for fast-start behavior, but no improvements in performance at the whole animal level were found between 8 and 21 degrees C.