Phosphatases and oxidative enzymes in the kidney of the Prussian carp (Carassius auratus gibelio Bloch) adapted to salt water

The distribution and activities of phosphatases and oxidative enzymes have been determined with the help of histochemical methods in the kidney of the Prussian Carp, a stenohaline freshwater-fish. In addition to fish maintained in freshwater aquaria, a group of the animals used has been adapted to seawater of moderate salinity. The following pattern of enzyme reaction intensities has been observed in the various kidney structures: Strong reactions of alkaline phosphatase in the nephron are confined to the glomerular capillary convolute and the brush border of proximal segments. Equally enzyme activities are observed in the connective tissue sheath of the collecting duct -- archinephric duct system. Acid phosphatase can be detected in all segments of the nephronic tubule, strong activities are found in the proximal segment (P I), in the epithelium of the archinephric duct, and, especially, in the interstitial tissue. ATPase reacts strongly positive in epithelial cells of the distal tubule and the collecting duct -- archinephric duct system. ATPase reactions are inhibited by Ouabain, and therefore can be regarded as reactions of Na--K-ATPase. Mitochondrially bound oxidative enzymes, connected with the citric acid cycle and the respiratory chain, show very strong reaction intensities in the distal tubule and the collecting duct- archinephric duct system, while the glomeruli generally exhibit negative reactions. Lactate -- and malate dehydrogenases are found to react weakly to negatively throughout the whole kidney. Maintenance in seawater does not deeply affect the enzyme pattern of the kidney of the Prussian carp, with exception of some oxidative enzymes, reacting weaker in the distal tubule and the collecting duct-archinephric duct system. In addition, the epithelial cells of the archinephric duct of seawater adapted fish show a marked apical localization of reaction products for these enzymes. Possible relations between enzyme histochemistry and fish kidney physiology are discussed, in connection with comparative aspects of the enzyme histochemistry of the vertebrate kidney. A short review of normal histology and function of the kidney of the Prussian carp is added.     

Ecological and genetic mechanisms of the dynamics of population abundance in silver crucian carp (Carassius auratus gibelio (Bloch, 1782)) from the Tsimlyansk Reservoir

Silver crucian carp is the dominant commercial fish of the Tsimlyansk Reservoir (the Don River). A retrospective analysis of the ecological and genetic factors determining the dynamics of the silver crucian carp population at different stages of reservoir functioning was performed. At the most recent stage, the lake-swamp environmental conditions suitable for crucian carp and a lack of any dependence on other cyprinid fishes during the reproduction of this species determine its domination in the reservoir??s fish community. The size, sex, and genetic structures of the crucian carp population, characterized by numerous age groups and low linear and weight growth rates, are presented.     

Inheritance of microsatellite DNA in bisexual gynogenesis complex of Fangzheng silver crucian carp,Carassius auratus gibelio (Bloch)

Five gynogenetic progeny groups of silver crucian carp Carassius auratus gibelio were produced and sex ratios (males:total progeny) of each of the progeny groups were analysed. About 110 males and 366 females were genotyped at 15 microsatellite loci for comparison with their parents to (1) verify the gynogenesis status of Fangzheng C. auratus gibelio, (2) detect the incorporation of paternal genetic material into the offspring and (3) study the possible association of genetic exchange at microsatellite loci with the existence of sex. The sex ratios in progenies of five groups were highly variable, but all had significant female bias. The sex ratio ranged from 0 to 0·37. Significant differences in the sex ratio within and between groups were also found. Microsatellite genotyping at 15 loci showed that 100 and 97% of the progeny shared the same genotype with the mother in four groups and in one group, respectively, confirming that gynogenesis is the general mechanism of reproduction in C. auratus gibelio. However, 0·63% of all offspring did show incorporation of paternal genetic material. No single loci tested were associated with the occurrence of male progeny, indicating unknown genetic mechanisms for sex determination in C. auratus gibelio.     

Identification of natural hybrids of gibel carp Carassius auratus gibelio (Bloch) and crucian carp Carassius carassius (L.) from lower Dyje River floodplain (Czech Republic)

Morphometric and genetic variation were examined in parental Carassius auratus gibelio and Carassius carassius individuals, and their natural hybrids. Of meristic traits, only the number of gill rakers clearly distinguished hybrids (39·4 ± 1·4) from parental C. a. gibelio (48·3 ± 0·7) and C. carassius (28·6 ± 1·1). MtDNA sequences showed that the hybrids were descendants of female C. a. gibelio . Microsatellite analysis confirmed the presence in hybrids of variants typical of C. a. gibelio and C. carassius .     

Polymorphic microsatellites from silver crucian carp (Carassius auratus gibelio Bloch) and cross‐amplification in common carp (Cyprinus carpio L.)

Fifteen polymorphic microsatellites were isolated from the genome of silver crucian carp (Carassius auratus gibelio Bloch). Allele numbers ranged from two to four with an average of 2.7/locus, and the proportion of tri‐ and diallelic heterozygotes was 99.3%. The individuals tested seem to have originated from two different clonal lines: 14 of 16 showed the same genotype at all loci tested, whereas the remaining two were also identical, but different from the former ones. Eleven out of 15 primer pairs cross‐amplified products from the genome of common carp, whereas only five from that of zebrafish.     

Isolation and characterization of microsatellite markers from Fangzheng silver crucian carp,Carassius auratus gibelio (Bloch), and cross‐amplification in the closely related species crucian carp,Carassius auratus auratus (Linnaeus)

We report the development of 20 microsatellite markers for Fangzheng silver crucian carp, Carassius auratus gibelio (Bloch). Nineteen out of 20 showed polymorphism with alleles ranging from two to 14. These loci were screened to amplify the closely related species crucian carp, Carassius auratus auratus (Linnaeus) and all of them can amplify DNA with the size similar to the former. The origin of silver crucian carp is in issue and the population genetic structure is still unclear. Microsatellite markers isolated from the silver crucian carp and their utility in the crucian carp will be useful for these researches.     

Effect of avermectin (AVM) on the expression of γ‐aminobutyric acid A receptor (GABAAR) in Carassius gibelio (Bloch, 1782)

This study describes the effect of avermectin (AVM) on the expression of γ‐aminobutyric acid A receptor (GABA_AR) in Carassius gibelio. To assess the specific expression of GABA_AR in the brain, gonads, liver, kidneys, heart, muscles, and skin of C. gibelio, the expression of GABA_AR α1 subunit (GABA_ARα1) was measured by Western blotting. To study the effects of AVM on the expression of GABA_AR, the median lethal concentration (LC₅₀) at 24, 48, and 96 h of AVM was determined and the expression of GABA_AR in the brain, liver, and kidneys of the corresponding C. gibelio evaluated by Western blotting and immunohistochemistry. The results show that GABA_AR was expressed in the brain, gonads, liver, kidneys, heart, intestines, muscles, and skin, while primarily distributed in the central nervous system and moderately distributed in peripheral tissues. The expression of GABA_AR in the brain, liver, and kidney tissues of C. gibelio was increased with the treatment of AVM at 24 h LC₅₀, but attenuated by the treatment of AVM at 48 h LC₅₀ and 96 h LC₅₀. This suggests a threshold effect of AVM.     

Intestinal microbiota of gibel carp (Carassius auratus gibelio) and its origin as revealed by 454 pyrosequencing

The intestinal microbiota has received increasing attention, as it influences growth, feed conversion, epithelial development, immunity as well as the intrusion of pathogenic microorganisms in the intestinal tract. In this study, pyrosequencing was used to explore the bacterial community of the intestine in gibel carp (Carassius auratus gibelio), and the origin of these microorganisms. The results disclosed great bacterial diversities in the carp intestines and cultured environments. The gibel carp harbored characteristic intestinal microbiota, where Proteobacteria were predominant, followed by Firmicutes. The analysis on the 10 most abundant bacterial operational taxonomic units (OTUs) revealed a majority of Firmicutes in the intestinal content (by decreasing order: Veilonella sp., Lachnospiraceae, Lactobacillales, Streptococcus sp., and Lactobacillus sp.). The second most abundant OTU was Rothia sp. (Actinobacteria). The most likely potential probiotics (Lactobacillus sp., and Bacillus sp.) and opportunists (Aeromonas sp., and Acinetobacter sp.) were not much abundant. Bacterial community comparisons showed that the intestinal community was closely related to that of the sediment, indicating the importance of sediment as source of gut bacteria in gibel carp. However, 37.95 % of the OTUs detected in feed were retrieved in the intestine, suggesting that food may influence markedly the microbiota of gibel carp, and therefore may be exploited for oral administration of probiotics.     

Distribution, sex ratio and growth of Carassius gibelio (Bloch) in coastal and inland waters of Estonia (north-eastern Baltic Sea)

Gibel carp Carassius gibelio (Bloch) was first introduced into fish ponds and small lakes of Estonia in 1948–49, and first detected in Estonian brackish waters (Gulf of Riga) in 1985. Since the mid‐1990s, the species has spread along the entire Estonian Baltic coastline. Growth rate in the brackish water population does not differ much from freshwater populations, but the freshwater populations are gynogenetic (or show high dominance of females) in contrast to the Baltic Sea population, which presents a normal sex ratio. The recent explosion of this species in the Baltic Sea could be explained by unusually warm summers during the 1990s and by the low abundance of predatory fish.     

Characterization of bmp15 and its regulation by human chorionic gonadotropin in the follicle of gibel carp (Carassius auratus gibelio)

Bone morphogenetic protein (BMP15) is a member of the transforming growth factor β (TGF-β) superfamily with a key role in regulating follicle development in mammals and birds. However, potential ovarian roles of BMPs remain unexplored in teleosts. In this study, the full-length sequences of bmp15 were obtained using rapid-amplification of cDNA ends (RACE). The full-length cDNA sequence of bmp15 is 2217 bp which contained 214 bp 5'-UTR and 845 bp 3'-UTR. The open reading frame (ORF) sequence of bmp15 is 1158 bp, encoding a predicted protein of 385 amino acid residues. BMP15 has a specific RXXR protease cleavage site of TGF-β superfamily (is RIRR) and six conserved cysteine residues. Using real-time quantitative PCR revealed that bmp15 mRNA was largely expressed in the ovary and testis and mostly in oocytes within the follicle, slightly expressed in muscle, liver and pituitary. BMP15 is mainly present at stage I follicles by real-time quantitative PCR and immunohistochemistry. Phylogenetic analysis showed that gibel carp bmp15 was similar to bmp15 of zebrafish and other fish species. Treatment with human chorionic gonadotropin (hCG) in isolated follicles of gibel carp in vitro showed altered bmp15 mRNA expression: when treated with 10 ng/mL hCG for 10h, the expression level of bmp15 was significantly increased. However, with proceeding cultivation, the expression level of BMP15 mRNA decreased. The results of this study indicate that bmp15 may play a key role during development of follicles in gibel carp, especially in early stage follicles.     

银鲫肌酸激酶M3-CK cDNA的克隆及其表达特征

用抑制性差减杂交结合SMART cDNA合成和RACE—PCR技术克隆到雌核发育银鲫(Carassius auratus gibelio)肌酸激酶M3-CK基因的全长cDNA。银鲫M3-CK cDNA全长1551bp，编码380个氨基酸，与普通鲤鱼(cyprinus carpio)M3-CK的氨基酸序列同源性高达95％。种系分析表明，银鲫M3-CK与其它脊椎动物的肌肉型肌酸激酶聚为较近的一支，与鲤鱼的M3-CK聚在一起，与脑特异型肌酸激酶及线粒体型肌酸激酶分歧较大。虚拟Northern杂交显示银鲫M3-CK基因在胚胎发育中差异表达。RT—PCR表明，银鲫M3-CK基因在成熟卵母细胞和胚胎发育早期可检测到少量的转录产物，在胚胎发育期间从肌肉效应期开始转录，并一直持续表达。组织RT—PCR表明，银鲫M3-CK基因只在心脏和肌肉表达。     

Effect of feeding frequency on growth, feed utilization, and size variation of juvenile gibel carp (Carassius auratus gibelio)

Juvenile (3.0 ± 0.2 g) gibel carp (Carassius auratus gibelio) were fed to satiation for 8 weeks to investigate the effect of feeding frequency on growth, feed utilization and size variation. Five feeding frequencies were tested: two meals per day (M2), three meals per day (M3), four meals per day (M4), 12 meals per day (M12) and 24 meals per day (M24). The results showed that daily food intake increased significantly with the increase in feeding frequency and there was no significant difference between daily food intakes in M12 and M24 treatments. Growth rate, feed efficiency increased significantly with increasing feeding frequencies. Size variation was not affected by feeding frequency. Apparent digestibility of dry matter was not influenced by feeding frequency, while apparent digestibility of protein and energy increased significantly at high feeding frequencies. The feeding frequency had no significant effect on the moisture, lipid, protein, or energy contents of gibel carp, while the ash content decreased with increased feeding frequency. It was recommended that 24 meals per day was the optimal feeding frequency for juvenile gibel carp.     

Investigation of long-term stress induced by several stressors by determination of the concentration of different blood plasma components in a model of Prussian carp (Carassius auratus gibelio BLOCH, 1783) and Common carp (Cyprinus carpio L., 1758)

Several compounds (carbohydrates, proteins, hormones, etc.) were used in fish to quantify the level of stress. Our investigations focused on two parameters of the blood plasma: plasma glucose and serum/plasma fructosamine (SeFa) that has not been tested on fish as yet. Experiments were conducted on two fish species. The concentrations of these components were investigated on Common carp (Cyprinus carpio L., 1758) and on Prussian carp (Carassius auratus gibelio BLOCH, 1783) from the G?d?ll?-Isaszeg pond system by creating conditions different from ideal. Stress effects caused a fluctuating tendency in blood plasma glucose levels each week for both Common carp and Prussian carp, thus, there was no steady growth. However, SeFa concentrations exactly followed stress effects, moreover, it tolerated short-term negative effects (handling of fish, blood sampling) and did not cause alterations at individuals blood samplings. This experimental method can offer assistance to farmers in the daily routine (e.g. in fish transport) and in the technology of propagation.     

Effect of inclusion of blue-green algae meal on growth and accumulation of microcystins in gibel carp (Carassius auratus gibelio)

Six isonitrogenous (crude protein content: 38%) and isoenergetic (gross energy content: 17 kJ g^?1) diets were formulated to investigate the effects of inclusion of blue‐green algae meal on gibel carp (Carassius auratus gibelio). In each diet, 15% of the protein was supplied by fishmeal; the remainder was supplied by soybean meal and blue‐green algae meal. Diet 1 was used as control with no blue‐green algae meal whereas the content in diets 2–6 was 15.15, 29.79, 44.69, 59.58 and 74.48%, respectively. Each diet was fed to five groups of gibel carp for 12 weeks in a flow‐through system. Final body weight and specific growth rate (SGR) of fish fed diet 5 were significantly lower than the control diet (P < 0.05). Mortality of gibel carp increased with increase in algae meal inclusion (P < 0.05), but there was no significant difference between fish fed diets 3–6 (P > 0.05). Feed conversion efficiency (FCE) decreased with the increase in algae meal inclusion (P < 0.05). Fish‐fed diet 6 showed the highest feeding rate (P < 0.05), while there were no significant differences among the other groups (P > 0.05). Apparent digestibility coefficient of dry matter, protein, and energy decreased with increasing algae meal inclusion in the diets (P < 0.05). Aspartate aminotransferase (GOT) activity in the liver was not significantly different among groups (P > 0.05). Liver alanine aminotransferase (GPT) activity of fish‐fed diets 4, 5 and 6 was significantly lower than the control diet (diet 1; P < 0.05). Microcystins in the muscle, liver, gallbladder, and spleen increased with increasing algae inclusion (P < 0.05).     

Effects of mannan oligosaccharide on the physiological responses,HSP70 gene expression and disease resistance of Allogynogenetic crucian carp (Carassius auratus gibelio) under Aeromonas hydrophila infection

We evaluated the effect of dietary supplementation with mannan oligosaccharide (MOS) on the resistance to Aeromonas hydrophi1a infection in Allogynogenetic crucian carp. The fish were randomly divided into five groups: a control group was fed with basal diet, and four treatment groups fed with basal diet supplemented with 60, 120, 240, 480 mg/kg MOS for 10 weeks, respectively. We then challenged the fish with A. hydrophi1a and recorded the mortality and the changes in serum cortisol, T3, T4, lysozyme, alkaline phosphatase (ALP), globin and hepatic total anti-oxidative capacity, superoxide dismutase (SOD), malondialdehyde (MDA) and the relative expression of heat shock protein 70 (HSP70) mRNA for a period of 7 d. Supplementation with 240 mg/kg MOS significantly increased serum ALP activity before infection, 1d and 2d after infection, serum globin concentration prior to infection, 1d and 7d after infection, serum lysozyme activity at 2d after infection, T3 concentration at 2d after infection, hepatic total anti-oxidative capacity prior to infection, hepatic SOD activity at 7d after infection and reduced serum cortisol concentration at 2d after infection, hepatic malondialdehyde content at 1d and 2d after infection. Supplementation with 480 mg/kg MOS significantly increased serum ALP activity before infection, 1d and 2d after infection, T3 content 1d after infection, T4 content prior infection and 7d after infection, serum globin concentration prior to infection, 1d and 7d after infection, serum lysozyme activity prior infection and 1d after infection, serum total anti-oxidative capacity prior to infection and 7d after infection, hepatic SOD activity at 7d after infection and the relative level of hepatic HSP70 mRNA at 2d and 7d after infection, had decreased levels of serum cortisol concentration before the infection, at 2d after infection, T4 concentration at 1d and 2d after infection, hepatic malondialdehyde content at 1d and 2d after infection. Mortality was significantly lower in the group of 240 and 480 mg/kg MOS than the control. Our results suggest that ingestion of a basal diet supplemented with 240–480 mg/kg MOS can enhance resistance against pathogenic infections in Allogynogenetic crucian carp.     

The effect of different dietary iron levels on growth and hepatic iron concentration in juvenile gibel carp (Carassius auratus gibelio)

An 83-day growth trial was conducted using a flow-through system to examine the effects of different dietary iron levels on growth and hepatic iron concentration in juvenile gibel carp ( Carassius auratus gibelio ). Six purified diets supplemented with different levels of iron (0, 10, 30, 60, 100 and 200 mg kg⁻¹) (as ferrous sulfate) were fed to triplicate groups of fish (initial weight 2.12 ± 0.00 g per fish). The results showed that the addition of iron to the basal diet did not significantly affect the specific growth rate (SGR), feed efficiency (FE), survival, red blood cell amount (RBC), hemoglobin content (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) or mean corpuscular hemoglobin concentration (MCHC). Hepatic iron concentration and hematocrit (Hct) were significantly influenced by dietary iron level (P < 0.05). On the basis of the iron concentration for the maintenance of optimum hepatic iron concentration and Hct, it was concluded that the dietary iron concentration of juvenile gibel carp should be not less than 202 mg Fe kg⁻¹ diet.     

Hybrid origins and F1 dominance in the free-floating, sterile bladderwort, Utricularia australis f. australis (Lentibulariaceae)

Abandonment of sexual reproduction is a well-known characteristic in aquatic plants, while the causes, levels, and consequences of sterility are often unknown. Utricularia australis f. australis (Lentibulariaceae) is a free-floating, sterile bladderwort distributed widely in temperate and tropical regions. Experimental crosses in cultivated conditions, AFLP analysis, and cpDNA haplotypes of natural populations clearly demonstrated that U. australis f. australis originates from the asymmetric hybridization between two parental taxa: U. australis f. tenuicaulis (mostly as female) and U. macrorhiza (mostly as male). No post-F(1) hybrids were detected using the additive patterns of AFLP bands combined with the observation of extensive sterility in U. australis f. australis. Recurrent hybridizations and subsequent perpetuation by asexual reproduction were demonstrated by the unique, but monomorphic, AFLP genotypes observed in each U. australis f. australis population. Hybrids and parental species did not coexist, implying the superiority of the hybrid U. australis f. australis in certain environmental conditions. It remains unclear whether populations of U. australis f. australis are maintained by colonizing propagules or as relicts of past hybridization events.     

The kidney of the prussian carp, Carassius auratus gibelio (Cyprinidae). III. Glycogen-rich cells in the distal segment of nephronic tubule

Glycogen may be present in considerable amount in the distal segment of the nephronic tubule of a teleost freshwater fish, as revealed by light- and electron-microscopical observation. Adaptation of Crassiss auratus gibelio to increased salinity causes alterations of the cell fine structure (e.g. mitochondria and baso-lateral infoldings) but apparently does not influence deposition of glycogen. However glycogen storage is directly controlled by environmental temperature and may be part of an annual rhythm in carbohydrate metabolism.     

粪便收集时间和饲料中肉骨粉含量对异育银鲫(Carassius auratus gibelio) 消化率的影响

本研究探讨了通过收集器不同粪便收集时间和饲料中肉骨粉(MBM)含量对异育银鲫干物质、蛋白、能量、磷的表观消化率 (ADC) 影响.不同梯度(0, 20, 40, 60, 80 ,100%)的肉骨粉替代鱼粉(FM) 蛋白配制成六种等氮 (粗蛋白: 410 g/kg) 等能 (总能: 18 kJ/g) 的饲料,通过11周的饲养实验,实验开始后2周开始收集粪便,收集时间分别是:排粪后 1 min, 投喂后4h和16h. 结果表明,干物质、蛋白、能量、磷的消化率明显随粪便收集时间增加而升高(p<0.05),但在高肉骨粉替代饲料中差异不显著(p>0.05). 干物质、蛋白、能量、磷的消化率随饲料中肉骨粉含量的增加呈线性或近线性下降.因此,在消化率测定中应该尽快收集排出的粪便以保证消化率的真实性.消化率是影响肉骨粉利用一个因素.