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.     

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.     

Genomic resources and microarrays for the common carp Cyprinus carpio L.

The common carp is an important fish species satisfying ornamental, food and recreational fisheries' needs worldwide, but in common with other cyprinid fishes, it is particularly renowned for its environmental tolerance. Investigating the mechanistic basis of growth, disease and environmental tolerance is greatly enhanced by access to a comprehensive list of gene sequences and post-genomic technologies. The current status of genomic resources is described for this species including 40 k cDNA clone collections, their associated expressed sequence tags (ESTs) and a developing series of 13 k–26 k cDNA microarrays fabricated from amplicons. The arrays have been directed at questions of response to environmental stress (cold and hypoxia), viral and bacterial disease and ectoparasite infection. Consequently, clones from a wide range of tissues were prepared. The authors discuss how these resources were generated and their application. Evidence is presented supporting that the carp microarray may also be useful as a heterologous set of probes in studies of other fish species.     

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.     

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.     

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.     

Specific dynamic action and feeding metabolism in common carp,Cyprinus carpio L.

• 1.1. Oxygen uptake attributable to Specific Dynamic Action (SDA) was measured in common carp, Cyprinus carpio L. (63.6–84.0 g) fed on 20, 35 and 50% dietary protein at 0.40 to 1.00% ration levels at 28°C.
• 2.2. After feeding both SDA magnitude and mean peak oxygen consumption increased directly with dietary protein and ration levels. SDA duration was not significantly related to dietary protein but significantly increased with ration levels.
• 3.3. SDA coefficients were 8.99, 13.51 and 15.94% with 20, 35 and 50% dietary protein showing a direction relationship to the protein content. The SDA coefficient did not change with ration size.
• 4.4. SDA models resulting from this work are of great interest for the aquaculturist, as post-feeding oxygen requirements in an intensive fish culture can be predicted where dietary protein and ration levels are known.

     

The eye lens weight and age in the common carp, Cyprinus carpio L.

The validity of the use of the weight of dried eye lenses as an indicator of age in the common carp, Cyprinus carpio L., is tested. There is a significant difference between males and females for fish of two and three years old. Otherwise no significant difference is noted between sexes. The linear relationship between the dry weight of eye lenses and age + 1 are: In Y + 1= 0.5202 + 16.4928 X ( r = 0.93) for female and ln Y + 1=0.4276 + 16.7364 X ( r = 0.94) for male.
The method for determining age is valuable for fish until three years old. However for older fish, in spite of a correlation coefficient between lens weight and age and even with a significant difference between annual groups, the age determination may be misleading due to the overlap in lens weights. In conclusion therefore this method may not be useful for back calculation of growth, for production estimates or studies in which accurate estimates of age are needed.     

Induced triploidy in carp, Cyprinus carpio L.

A method for mass production of triploid carp was developed by the cold treatment of eggs after fertilization. Triploidy was demonstrated by cytophotometry and chromosome preparation techniques. Of the haploid embryos, 100% showed morphological abnormalities and died soon after hatching. Haploid embryos of maternal and paternal origin occurring in the course of cold treatment were distinguished by using a genetic marker. Among morphologically normal larvae, the frequency of triploidy was 100%, and the viability of the triploid embryos, larvae and the juvenile fish did not differ from the diploid control. Sex differentiation started in the triploid fish, but was greatly retarded. Gonad size and the small number of growing oocytes suggest that most of the triploid individuals will be sterile. Triploid carp grew at the same rate as diploid controls in the laboratory test.     

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     

Investigation on carp, Cyprinus carpio L. gynogenesis

A reliable method for gynogenetic mass-production has been developed in carp ( Cyprinus carpio L.). The effect of different cold shock treatments applied after fertilization were examined. The yield of viable diploid gynogenetic animals could be significantly increased when the cold shock was applied 5 min or 15 min after fertilization. A negative correlation has been found between the effectiveness of these two treatments, so both were used on separate batches of eggs. By means of gynogenesis, the crossover frequency and map distance of the transferrin locus have been determined. Successful pilot experiments were made on grass carp ( Ctenopharyngodon idella Val.) and sheatfish ( Silurus glanis L.) with respect to gynogenetic mass production.     

The biology of the common carp, Cyprinus carpio L. in the Camargue, southern France

Carp were sampled monthly during one and a half years in the Etang du Vaccarès, Camargue, southern France using fyke nets. Densities of carp in temporary marshes and canals were determined using rotenone. Carp is the dominant species in biomass in the fresh and brackish waters (14%0) with densities from 11–58 kg/ha in temporary marshes and up to ten times greater in the canals. Scales were used to determine age and growth of 201 carp. The relative condition factor of female and male mature and unsexed fish are not statistically different throughout the year and follow the variations of gonadal development in spring. The best predictive equation of fecundity, Log F = 7.03504 + 0.83829 log ovary weight, was found using a stepwise multiple regression. The sex-ratio in the temporary marshes (♂ : ♀; 1.66–1.76) is greater than the general sex-ratio of the monthly samples (0.67). The diet of carp is characterized by the presence of large numbers of seeds and the absence of large benthic invertebrates. Predation by fish-eating birds and carnivorous fish is minimal, and the annual drying of many marshes is considered the main mortality factor., Accepted 22 July 1980     

Larval development of carp, Cyprinus carpio L., in acidic water

Laboratory experiments measuring survival and growth at various pH levels and two temperatures indicate that the threshold of pH of water below which larval development of carp is stopped is 5.0–5.2, the development of some individuals being stopped within the pH range 5.0–5.5. Inhibition of development is due to the inability of a larva to fill its swimbladder with air, this preventing swimming and leading to death from starvation. In water of pH 5.5–6.0 the development may be undisturbed, though slower. The effect of water acidification is reflected in slower growth rate and prolongation of the larval stages of development.     

Gene transfer in common carp (Cyprinus carpio L.) by microinjection into the germinal disc

We report here on the microinjection of the human growth hormone gene (hGH) into the germinal disc of common carp one-cell embryos. For microinjection, a linear 4.1 kb EcoRi-DNA fragment containing the mouse metallothionein-I promoter (mMT-I), fused to a structural gene coding for the hGH, was used. Of the 14 injected embryos, 9 developed to an age of 60 d. Of these nine fish, two were found to be transgenic and had integrated two to four copies per cell of the hGH construct.     

Soybean meal induces intestinal inflammation in common carp (Cyprinus carpio L.)

The development of soybean meal (SBM) induced enteritis in the hindgut of the omnivorous common carp (Cyprinus carpio L.). The developed condition was assessed when carp, continuously fed on animal protein, were transferred to a diet in which 20% of the protein was replaced by SBM. After week 1, most of the inflammation parameters were already present, but at week 3, a strong aggravation of the condition was observed which included a shortening of the mucosal folds, the disappearance of the supranuclear vacuoles, an increased number of goblet cells, a thickened lamina propria and sub-epithelial mucosa with increased numbers of basophilic granulocytes as well as a decreased uptake capacity of enterocytes (impaired endocytosis and microvilli). Contrary to previous observations made with respect to Atlantic salmon, common carp start to recover from the fourth to the fifth week after switching to SBM feeding. At this stage, the supranuclear vacuoles refill and most of the parameters revert to basal levels. During the enteritis process, a real-time quantitative PCR analysis was conducted to measure the expression of inflammatory and anti-inflammatory cytokine genes in the isolated intraepithelial lymphocytes (IEL). The pro-inflammatory interleukin 1 beta (IL-1 beta) and tumour necrosis factor alpha1 (TNF-alpha1) genes were up-regulated during the inflammation process while the anti-inflammatory interleukin 10 (IL-10) was down-regulated after an initial up-regulation at week 1. Transforming growth factor beta (TGF-beta) expression showed an up-regulation from week 3 onwards despite the high Ct value and the low primer efficiency shown. This study confirms the contribution of IEL (mainly T-like cells) and basophils in the enteritis process. In addition, the results show a clear involvement of up- and down-regulated cytokine genes in both the onset and recovery of the SBM-induced enteritis in the hindgut of carp.     

Population genetics of invasive common carp Cyprinus carpio L. in coastal drainages in eastern Australia

The common carp Cyprinus carpio introduced in two drainages in eastern Australia are largely descended from European common carp, and in a third drainage they descend largely from East Asian common carp. The partial genetic differentiation among the species in those drainages is consistent with their origins.     

Response of common carp (Cyprinus carpio L.) leucocytes to hormone-induced stress

The influence of cortisone on leucocytes composition in the blood of common carp (Cyprinus carpio L.) is studied. Following the hormone injection, the relative number of leucocytes decreased and the number of neutrophils and blast-form cells increased in the leucocyte spectrum of experimental fish.     

Oral absorption of biologically active insulin in common carp (Cyprinus carpio L.).

1. Bovine insulin dissolved in 0.05 M deoxycholic acid was absorbed through oral intubation in fish weighing 200-300 g. 2. The peak of absorption appeared in all fish, 30-45 min after intubation and was followed by a gradual decrease. The extent of absorption was extremely variable, with up to a 20-fold difference between individuals. No detectable insulin was found in fish intubated with vehicle. 3. The absorbed hormone retained 17-88% of its lipogenic bioactivity in vitro. The absorbed insulin lowered the levels of several amino acids in the intubated fish, indirectly indicating that its bioactivity was also retained in vivo.