Sample records for sheatfish silurus glanis

  1. Complete genome sequence of the European sheatfish virus.

    Mavian, Carla; López-Bueno, Alberto; Fernández Somalo, María Pilar; Alcamí, Antonio; Alejo, Alí


    Viral diseases are an increasing threat to the thriving aquaculture industry worldwide. An emerging group of fish pathogens is formed by several ranaviruses, which have been isolated at different locations from freshwater and seawater fish species since 1985. We report the complete genome sequence of European sheatfish ranavirus (ESV), the first ranavirus isolated in Europe, which causes high mortality rates in infected sheatfish (Silurus glanis) and in other species. Analysis of the genome sequence shows that ESV belongs to the amphibian-like ranaviruses and is closely related to the epizootic hematopoietic necrosis virus (EHNV), a disease agent geographically confined to the Australian continent and notifiable to the World Organization for Animal Health.

  2. Diel dualism in the energy consumption of the European catfish Silurus glanis.

    Slavík, O; Horký, P


    Twenty individuals of the largest European freshwater predator, the European catfish Silurus glanis, were tagged with electromyogram (EMG) physiological telemetry sensors. The fish were observed during diel cycles during the spring and summer in the Elbe and Berounka Rivers, Czech Republic. The purpose of this study was to determine whether diel dualism in the activity of S. glanis occurs naturally or is induced by the laboratory environment and by the conditions occurring in aquaculture. The results obtained from the riverine environment tended to show dualism in the use of the light and dark phases of the day because 35% of the individuals varied from a site-specific common diel activity pattern. The EMG values increased in accordance with the mass (M) of the fish. To eliminate the influence of M on individual energy consumption, the EMG records were analysed in terms of the EMG:M ratios. High individual variability was found in these ratios. The diel activity pattern of the individuals with relatively high energy consumption differed from the common diel activity pattern. In contrast, the fish that adopted the common diel activity pattern displayed relatively low energy consumption. The results of this study indicated that dualism and energy consumption are related. The EMG values also varied with the values of the environmental variables. Increasing temperature was associated with high EMG values, whereas the EMG values decreased with increasing flow. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  3. Socio-economic drivers of specialist anglers targeting the non-native European catfish (Silurus glanis in the UK.

    E M Ann Rees

    Full Text Available Information about the socioeconomic drivers of Silurus glanis anglers in the UK were collected using questionnaires from a cross section of mixed cyprinid fisheries to elucidate human dimensions in angling and non-native fisheries management. Respondents were predominantly male (95%, 30-40 years of age with £500 per annum. The proportion of time spent angling for S. glanis was significantly related to angler motivations; fish size, challenge in catch, tranquil natural surroundings, escape from daily stress and to be alone were considered important drivers of increased time spent angling. Overall, poor awareness of: the risks and adverse ecological impacts associated with introduced S. glanis, non-native fisheries legislation, problems in use of unlimited ground bait and high fish stocking rates in angling lakes were evident, possibly related to inadequate training and information provided by angling organisations to anglers, as many stated that they were insufficiently informed.

  4. Example of the application the microsatellite DNA fragments in the study of farmed European catfish (Silurus glanis, L. broodstock

    Kuciñski Marcin


    Full Text Available European catfish, Silurus glanis L., is the second largest freshwater fish in Europe. The species is very popular among the farmers, as it is one of the most promising European aquaculture species. Despite the growing importance of European catfish in freshwater aquaculture, the genetic data available on this species are still limited. The main purpose of the present study was to develop a reliable, feasible genetic protocol for future studies on European catfish populations and broodstocks in Poland. The genetic characteristics of the tested fish group were based on genetic parameters such as the polymorphism information content (PIC, the effective population size (Ne, the inbreeding coefficient (Fis, and the Garza-Williamson index (M, among others. Additionally, the potential effects of a genetic bottleneck on the genetic variation of the broodstock were examined. The genetic analysis protocol described in this study can be used to establish genetic-based records for European catfish broodstocks, including for sperm cryobanking. This approach will be useful for elaborating the selection procedures that allow for optimal assemblages of spawning pairs in artificial reproduction. The application of the genetic analysis protocol in practice will permit maintaining high quality in European catfish broodstocks.

  5. Effects of Temperature on Auditory Sensitivity in Eurythermal Fishes: Common Carp Cyprinus carpio (Family Cyprinidae) versus Wels Catfish Silurus glanis (Family Siluridae)

    Maiditsch, Isabelle Pia; Ladich, Friedrich


    Background In ectothermal animals such as fish, -temperature affects physiological and metabolic processes. This includes sensory organs such as the auditory system. The reported effects of temperature on hearing in eurythermal otophysines are contradictory. We therefore investigated the effect on the auditory system in species representing two different orders. Methodology/Principal Findings Hearing sensitivity was determined using the auditory evoked potentials (AEP) recording technique. Auditory sensitivity and latency in response to clicks were measured in the common carp Cyprinus carpio (order Cypriniformes) and the Wels catfish Silurus glanis (order Siluriformes) after acclimating fish for at least three weeks to two different water temperatures (15°C, 25°C and again 15°C). Hearing sensitivity increased with temperature in both species. Best hearing was detected between 0.3 and 1 kHz at both temperatures. The maximum increase occurred at 0.8 kHz (7.8 dB) in C. carpio and at 0.5 kHz (10.3 dB) in S. glanis. The improvement differed between species and was in particular more pronounced in the catfish at 4 kHz. The latency in response to single clicks was measured from the onset of the sound stimulus to the most constant positive peak of the AEP. The latency decreased at the higher temperature in both species by 0.37 ms on average. Conclusions/Significance The current study shows that higher temperature improves hearing (lower thresholds, shorter latencies) in eurythermal species from different orders of otophysines. Differences in threshold shifts between eurythermal species seem to reflect differences in absolute sensitivity at higher frequencies and they furthermore indicate differences to stenothermal (tropical) species. PMID:25255456

  6. Mercury and selenium in European catfish (Silurus glanis) from Northern Italian Rivers: can molar ratio be a predictive factor for mercury toxicity in a top predator?

    Squadrone, S; Benedetto, A; Brizio, P; Prearo, M; Abete, M C


    The study of mercury and selenium bioaccumulation in fish is crucially important for evaluating the extent of contamination in freshwater environments, and the possible health risk posed for humans when the antagonistic interactions of these two elements are considered. Several factors affect the risk of mercury intake from fish consumption, including mercury levels, human consumption patterns, and sensitive populations (e.g., pregnant women, foetuses, young children and unknown genetic factors). The protective effects of selenium on mercury toxicity have been extensively publicised in recent years, particularly targeting fish consumers. In this study, mercury (Hg) and selenium (Se) concentrations were determined in the muscle of European catfish (Silurus glanis) collected from North Italian Rivers. Differences in mercury and selenium levels, as a function of size, gender and location were investigated. Hg was strongly related to length, gender and location, while Se levels are not dependent on fish size or location. The mean Se/Hg molar ratio was strongly affected by location, and significantly related to length and age. Selenium was in molar excess of mercury in all sites, with a rank order of mean Se/Hg molar ratio of the Parma River (2.55)>Po River (1.71)>Tanaro River (1.66)>Bormida River (1.36). However, in 37% of analyzed samples, Hg exceeded the maximum level set by 1881/2006/EC and 629/2008/EC in fish muscle. The molar ratio of Se/Hg was 0.5mg/kg), and therefore the mean molar ratio cannot be considered as a safety criterion in top predator fish. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Optimalization of artificial propagation in European catfish, Silurus glanis L

    Linhart, Otomar; Gela, David; Rodina, Marek; Kocour, Martin


    Roč. 235, - (2004), s. 619-632 ISSN 0044-8486 R&D Projects: GA MŠk OK 187; GA ČR GA524/03/0178 Institutional research plan: CEZ:AV0Z5045916 Keywords : eggs * sprematozoa * aquaculture Subject RIV: ED - Physiology Impact factor: 1.627, year: 2004

  8. European catfish (Silurus glanis) as a freshwater apex predator drives ecosystem via its diet adaptability

    Vejřík, Lukáš; Vejříková, Ivana; Blabolil, Petr; Eloranta, A. P.; Kočvara, Luboš; Peterka, Jiří; Sajdlová, Zuzana; Chung, S.H.T.; Šmejkal, Marek; Kiljunen, M.; Čech, Martin


    Roč. 7, November (2017), č. článku 15970. ISSN 2045-2322 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) 7F14316; GA MŠk(CZ) LM2015075; GA MŠk(CZ) EF16_013/0001782 EU Projects: European Commission(XE) 677039 - ClimeFish Institutional support: RVO:60077344 Keywords : foraging ecology * individual niche specialization * interspecific interaction * multiple predator effect Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 4.259, year: 2016

  9. Cryopreservation of European catfish Silurus glanis sperm: Sperm motility, viability and hatching success of embryos

    Linhart, Otomar; Rodina, Marek; Flajšhans, Martin; Gela, David; Kocour, Martin


    Roč. 51, č. 3 (2005), s. 250-261 ISSN 0011-2240 R&D Projects: GA ČR GA524/03/0178; GA AV ČR IBS5045314 Institutional research plan: CEZ:AV0Z50450515 Keywords : fish * sperm * aquaculture Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.765, year: 2005

  10. Carotenoid-enriched microalgal biomass as feed supplement for freshwater ornamentals: albinic form of wels catfish (Silurus glanis)

    Zaťková, I.; Sergejevová, M.; Urban, J.; Vachta, R.; Štys, Dalibor; Masojídek, Jiří


    Roč. 17, č. 3 (2011), s. 278-286 ISSN 1353-5773 R&D Projects: GA ČR GA521/09/0656 Institutional research plan: CEZ:AV0Z50200510 Keywords : carotenoid * Chlorella * microalga Subject RIV: EE - Microbiology, Virology Impact factor: 2.179, year: 2011

  11. Thirty-year-old paradigm about unpalatable perch egg strands disclaimed by the freshwater top-predator, the European catfish (Silurus glanis)

    Vejřík, Lukáš; Vejříková, Ivana; Kočvara, Luboš; Sajdlová, Zuzana; Chung, S.H.T.; Šmejkal, Marek; Peterka, Jiří; Čech, Martin


    Roč. 12, č. 1 (2017), č. článku e0169000. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) 7F14316; GA ČR GP206/09/P266 EU Projects: European Commission(XE) 677039 - ClimeFish Institutional support: RVO:60077344 Keywords : diet * impact on population * niche width * predator-prey interactions * reproductive effort Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.806, year: 2016

  12. Influence of Environmental Conditions in Ichthyophthiriasis Trigger to the Europeans Catfish Juveniles (Silurus Glanis Stocked into a Production System with Partially Reused Water

    Sandita (Placinta Ion


    Full Text Available Currently, in Romanian aquaculture, the rearing of the European catfish into intensive production systems raises a growing interest determined by its higher technological performances. In comparison with pond traditional aquaculture, the new farming systems are characterized by modified environmental conditions that may lead, in case of exceeding thresholds of tolerability, to occurrence of stress factors, thus setting the disease conditions. From this perspective, the purpose of this paper is to present the association circumstances of the predisposed environmental conditions that have weakened the fish body resistance promoting the pathological action of Ichthyophthirius multifiliis after the transfer of European catfish juveniles (G=33.6±1.7 g, L=17.5±2.9 cm from a pond system into a tank culture system with partially reused water. During a 21-day period, some restrictive parameters of water quality have registered values far beyond the optimum interval for wells juveniles growth (t≤16oC, CmaxN-NH4+=3.62mg/l, CmaxNO2-=9.18mg/l, CmaxCl2=0.1mg/l which caused the appearance of some characteristic symptoms, such as the gills brown coloration, masking the first symptoms of ichthyophthiriasis and contributing to the subclinical evolution of the disease. The concentrations of water chemical parameters were determined by spectrophotometer methods using Merck kits, analogous to standard methods. Subsequently, the “ich” diagnosis was confirmed by microscopic examination of the gills and skin scrapings highlighting the presence of parasites. In order to alleviate methaemoglobinaemia and parasite treatment, sodium chloride was gradually added in water till 1 ppt concentration. Maintaining the salinity of the system led to a reduction of gills parasitic intensity, while mature trophonts encapsulated in the skin were protected by mucus hypersecretion. Finally, the destruction of gill epithelium seriously affected the osmoregulation, resulting in fish death by asphyxia which led to a loss of 90% of the population.

  13. Enzyme treatment for elimination of egg stickness in tench (Tinca Tinca L.), European catfish (Silurus Glanis L.) and common carp (Cyprinus Carpio L.)

    Linhart, Otomar; Rodina, Marek; Gela, David; Flajšhans, Martin; Kocour, Martin


    Roč. 28, - (2004), s. 507-508 ISSN 0920-1742 R&D Projects: GA MŠk ME 403; GA MŠk ME 420; GA AV ČR IBS5045314 Institutional research plan: CEZ:AV0Z5045916 Keywords : aquaculture * egg * enzyme Subject RIV: ED - Physiology Impact factor: 0.399, year: 2004

  14. Establishment of a Zebrafish Infection Model for the Study of Wild-Type and Recombinant European Sheatfish Virus.

    Martín, Verónica; Mavian, Carla; López Bueno, Alberto; de Molina, Antonio; Díaz, Eduardo; Andrés, Germán; Alcami, Antonio; Alejo, Alí


    Amphibian-like ranaviruses include pathogens of fish, amphibians, and reptiles that have recently evolved from a fish-infecting ancestor. The molecular determinants of host range and virulence in this group are largely unknown, and currently fish infection models are lacking. We show that European sheatfish virus (ESV) can productively infect zebrafish, causing a lethal pathology, and describe a method for the generation of recombinant ESV, establishing a useful model for the study of fish ranavirus infections. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Female morphology of Philometra parasiluri (Nematoda, Philometridae), an ocular parasite of the Amur catfish Silurus asotus in Japan

    Moravec, František; Scholz, Tomáš; Kuchta, Roman; Grygier, M. J.


    Roč. 53, č. 2 (2008), s. 153-157 ISSN 1230-2821 R&D Projects: GA MŠk LC522; GA ČR(CZ) GA524/06/0170 Institutional research plan: CEZ:AV0Z60220518 Keywords : Philometra * Silurus * Japan Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.748, year: 2008

  16. The Annual Reproductive Cycle of Silurus microdorsalis, a Korean Endemic Species

    Ki, Se-Un; Lee, Won-Kyo


    ABSTRACT The annual reproductive cycle of the Korean endemic slender catfish, Silurus microdorsalis, was examined histologically regarding water temperature and day length of habitat, gonadosomatic index (GSI), and development characteristics of female and male gonads. The maximum GSI value was found in May, 1.23±0.33 and 11.77±3.23 for male and female respectively (habitat water temperature 21.5°C/13.59hr day length). On the other hand, the minimal level was 0.63±0.10 in July (26.5°C/14.17) for male and 1.36±0.08 in October (20°C/11.2hr) for female. We compared and calculated the stages of testis and ovary development process in order to determine the germ cell development characteristics and the reproductive cycle. According to results, we classified the annual reproductive cycle of the slender catfish into five stages: Growing phase (December-February), Mature phase (March-April), Ripe and spawning phase / Releasing phase in male (May-June), Degenerative phase (July-August), and Resting phase (September-November).

  17. Uptake, retention and organ/tissue distribution of 137Cs by Japanese catfish (Silurus asotus Linnaeus)

    Malek, M.A.; Nakahara, M.; Nakamura, R.


    The work describes the uptake, retention/biological elimination and organ/tissue distribution of 137 Cs by freshwater Japanese catfish (Silurus asotus Linnaeus) under laboratory conditions. The fish were divided into three groups based on their size and age and reared in 137 Cs-spiked water. The concentration of 137 Cs in the whole body of the live fish was measured at regular intervals up to 60 days. A significant accumulation of 137 Cs was found, but a steady state condition was not achieved by the end of the experiment. The bioaccumulation factors at steady state and the required time to reach steady state were estimated to be 1.55 and 255 days, 1.76 and 180 days and 1.99 and 160 days for large, medium and small size fish, respectively. To determine the effective half-life of 137 Cs, the fish were transferred and reared in the non-contaminated host water. The concentration of the remaining 137 Cs in the whole body of the live fish was measured up to 66 days. The average effective half-life of 137 Cs in the fish species was found to be ∼142 days for fish of all sizes. The distribution of 137 Cs in different organs/tissues of the fish was determined. Accumulation of 137 Cs in muscle/flesh of the fish was found to be ∼75% of whole body accumulation. The uptake rate and the retention capability of juvenile fish were found to be higher and therefore, these were more susceptible to 137 Cs than adult and old fish, and could be an important source of 137 Cs in the human food chain

  18. A unique epidermal mucus lectin identified from catfish (Silurus asotus): first evidence of intelectin in fish skin slime.

    Tsutsui, Shigeyuki; Komatsu, Yukie; Sugiura, Takaya; Araki, Kyosuke; Nakamura, Osamu


    The present study reports a new type of skin mucus lectin found in catfish Silurus asotus. The lectin exhibited calcium-dependent mannose-binding activity. When mannose eluate from chromatography with mannose-conjugated agarose was analysed by SDS-PAGE, the lectin appeared as a single 35-kDa band. Gel filtration showed that the lectin forms monomers and dimers. A 1216-bp cDNA sequence obtained by RACE-PCR from the skin encoded a 308 amino acid secretory protein with homology to mammalian and fish intelectins. RT-PCR demonstrated that the lectin gene was expressed in the gill, kidney and skin. Subsequent sequencing revealed the presence of an isoform in the gills. Antiserum detected the intelectin protein in club cells in the skin and gill, renal tubules and blood plasma. Although intelectin gene expression was not induced by in vivo bacterial stimulation, the intelectin showed agglutination activity against the pathogenic bacterium Aeromonas salmonicida, suggesting that the lectin plays an important role in self-defence against bacteria in the skin surface of the catfish. These findings represent one of the few examples of characterization and functional analysis of a fish intelectin protein.

  19. Effects of fasting and feeding on the fast-start swimming performance of southern catfish Silurus meridionalis.

    Yan, G J; He, X K; Cao, Z D; Fu, S J


    This study investigated the effects of fasting and feeding on the fast-start escape swimming performance of juvenile southern catfish Silurus meridionalis, a sit-and-wait forager that encounters extreme fasting and famine frequently during its lifespan. Ten to 30 days of fasting resulted in no significant change in most of the variables measured in the fast-start response except a 20-30% decrease in the escape distance during the first 120 ms (D 120ms ) relative to the control group (48 h after feeding). The ratio of the single-bend (SB) response (lower energetic expenditure) to the double-bend (DB) response increased significantly from 0% in the control group to 75 and 82·5% in the 20 and 30 day fasting groups, respectively. Satiated feeding (25% of body mass) resulted in a significantly lower (36·6%) maximum linear velocity (V max ) and a significantly lower (43·3%) D 120ms than in non-fed fish (control group, 48 h after feeding). Half-satiated feeding (12·5% of body mass), however, showed no significant effects on any of the measured variables of the fast-start response relative to control fish. It is suggested that the increase in the ratio of SB:DB responses with fasting in S. meridionalis may reflect a trade-off between energy conservation and maintaining high V max , while variables of fast-start performance were more sensitive to feeding than fasting might be an adaptive strategy to their foraging mode and food availability in their habitat. © 2015 The Fisheries Society of the British Isles.

  20. The effect of aerobic exercise and starvation on growth performance and postprandial metabolic response in juvenile southern catfish (Silurus meridionalis).

    Li, Xiu-Ming; Liu, Li; Yuan, Jian-Ming; Xiao, Yuan-Yuan; Fu, Shi-Jian; Zhang, Yao-Guang


    To investigate the effects of aerobic exercise and starvation on growth performance, postprandial metabolic response and their interaction in a sedentary fish species, either satiation-fed or starved juvenile southern catfish (Silurus meridionalis) were exercised at 25 °C under three water velocities, i.e., nearly still water (control), 1 body length (bl) s(-1) and 2 bl s(-1), for eight weeks. Then, the feed intake (FI), food conversion efficiency (FCE), specific growth rate (SGR), morphological parameters, resting ṀO2 (ṀO2rest) and postprandial ṀO2 responses of the experimental fish were measured. Exercise at a low velocity (1 bl s(-1)) showed no effect on any growth performance parameter, whereas exercise at a high velocity (2 bl s(-1)) exhibited higher FI but similar SGR due to the extra energy expenditure from swimming and consequent decreased FCE. Starvation led to a significant body mass loss, whereas the effect intensified in both exercise groups. Exercise resulted in improved cardio-respiratory capacity, as indicated by increased gill and heart indexes, whereas it exhibited no effect on resting and postprandial metabolism in S. meridionalis. The starved fish displayed significantly larger heart, gill and digestive tract indexes compared with the feeding fish, suggesting selective maintenance of cardio-respiratory and digestive function in this fish species during starvation. However, starved fish still exhibited impaired digestive performance, as evidenced by the prolonged duration and low postprandial metabolic increase, and this effect was further exacerbated in both the 1 and 2 bl s(-1) exercise groups. These data suggest the following: (1) aerobic exercise produced no improvement in growth performance but may have led to the impairment of growth under insufficient food conditions; (2) the mass of different organs and tissues responded differently to aerobic exercise and starvation due to the different physiological roles they play; and (3

  1. Evaluation of the Efficacy of Fermented By-product of Mushroom, Pleurotus ostreatus, as a Fish Meal Replacer in Juvenile Amur Catfish, Silurus asotus: Effects on Growth, Serological Characteristics and Immune Responses

    Katya, Kumar; Yun, Yong-hyun; Park, Gunhyun; Lee, Jeong-Yeol; Yoo, Gwangyeol; Bai, Sungchul C.


    The present experiment was conducted to evaluate the efficacy of dietary fermented by-product of mushroom, Pleurotus ostreatus, (FBPM) as a fish meal (FM) replacer in juvenile Amur catfish, Silurus asotus. A total number of 225 fish averaging 5.7±0.1 g (mean±standard deviation) were fed one of the five experimental diets formulated to replace FM with FBPM at 0%, 5%, 10%, 20%, and 30% (FBPM0, FBPM5, FBPM10, FBPM20, and FBPM30, respectively). At the end of eight weeks of the experiment, average weight gain (WG) of fish fed FBPM0 or FBPM5 were significantly higher than those of fish fed FBPM20 or FBPM30 diets (p<0.05). However, there was no significant differences in WG among the fish fed FBPM0, FBPM5 or FBPM10, and between fish fed FBPM10 or FBPM20, and also between those fed FBPM20 or FBPM30 diets. Lysozyme activity of fish fed FBPM0 or FBPM5 were significantly higher than those of fish fed FBPM10, FBPM20 or FBPM30 diets (p<0.05). The chemiluminescent response of fish fed FBPM5 was significantly higher than those of fish fed FBPM0, FBPM20 or FBPM30 diets (p<0.05). Broken line regression analysis of WG suggested that the maximal dietary inclusion level for FBPM as a FM replacer could be 6.3% without any adverse effects on whole body composition and on serological characteristics. Therefore, these results may indicate that the maximal dietary inclusion level of FBPM as a FM replacer could be 6.3% in juvenile Amur catfish. PMID:25178300

  2. [Role of Aeromonas in the monitoring of a hydroecosystem in the Volga-Caspian area].

    Obukhova, O V; Lartseva, L V; Lisitskaia, I A


    The paper gives data obtained over many years on the quantity of bacteria of the genus Aeromonas in the hydroecosystems of the delta of the Volga and Caspian Sea and in commercial fishes (sturgeon (Acipenseridae), pike perch (Stizostedion), carp (Cyprinus carpio), silurus (Silurus glanis), etc.). It provides a detailed analysis of their seasonal trends and spatial distribution, markers of their pathogenicity, and antibiotic resistance. The findings suggest that Aeromonas is a causative agent of sapronoses and meets the criteria for natural focal infections. They show a wide range of tolerance to the abiotic factors of hydroecosystems, as well as mixotrophy and autrophic nutrition in the environment and they are of great sanitary and hygienic importance.

  3. The concentration of active and inactive strontium in some Danube river samples

    Koshutich, K.; Lulich, S.


    The following fish species were investigated: Barbus barbus, Acipencer ruthenus, Abramis brama, Stizostedion lucioperca, Silurus glanis, Cyprinus caprio. The samples were collected during 1981. The inactive strontium in the water residue (after evaporation), sediment and fishes ewrw determined by nondestructive neutron activation analysis by using gamma couting system consisted of a 40 cm 3 Ge(Li) semiconductor rystal attached to a 4096-channel pulsehight analyser. The standard solution contained 5x10 -5 g of strontium per 100 lambda. Radioactive strontium was measured after several separation procedures. 90 SrCO 3 in equilibrium with its daughter 90 Y was detected in the β-low-level counting anticoincident system with gas-flow detector. The results confirmed the literature data that the sediment concentrations of the total strontium and the active 90 Sr are several times greater than those in water

  4. Energy costs of catfish space use as determined by biotelemetry.

    Ondřej Slavík

    Full Text Available Animals use dispersed resources within their home range (HR during regular day-to-day activities. The high-quality area intensively used by an individual, where critical resources are concentrated, has been designated as the core area (CA. This study aimed to describe how animals utilize energy in the HR and CA assuming that changes would occur according to the size of the used areas. We observed energetic costs of space use in the largest European freshwater predator catfish, Silurus glanis, using physiological sensors. Catfish consumed significantly more energy within the CA compared to the rest of the HR area. In addition, energetic costs of space use within a large area were lower. These results generally indicate that utilization of larger areas is related to less demanding activities, such as patrolling and searching for new resources and mates. In contrast, fish occurrence in small areas appears to be related to energetically demanding use of spatially limited resources.

  5. "Freshwater killer whales": beaching behavior of an alien fish to hunt land birds.

    Julien Cucherousset

    Full Text Available The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis to capture birds on land (i.e. pigeons, Columbia livia. Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ(13C and δ(15N of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface.

  6. Monogenean Parasites on the Gills of Some Fish Species from Lakes Sapanca and Durusu, Turkey.

    Erhan Soylu


    Full Text Available Sapanca ve Durusu Göllerindeki bazı balık türlerinin solungaçlarındaki Monogenean parazitler. Sapanca ve Durusu göllerindeki 11 balık türü; Silurus glanis, Esox lucius, Rutilus rutilus, Vimba vimba, Scardinius erythrophthalmus, Abramis brama, Tinca tinca, Cyprinus carpio, Rhodeus sericeus amarus, Chalcalburnus chalcoides, Rutilus frisii’den Monogenean parazitler çalışıldı. Dactylogyrus, Silurodiscoides, Tetraonchus ve Paradiplozoon genuslarına ait 19 monogenoid türü; Dactylogyrus sphyrna, D. vistulae, D. phoxini, D. difformis, D. difformoides, D. chalcalburni, D. bicornis D. nybelini, D. frisii, D. crucifer, D. cornu, D.cornoides, D. extensus, D. macracanthus, D. izjumovae, Silurodiscoides siluri, S.vistulensis, Tetraonchus monenteron ve Paradiplozoon sp. bulundu. D.bicornis, D.nybelini ve D.izjumovae Türkiye için yeni kayıtlardır

  7. Radioactive contamination of the significant fish species in fish-ponds and in natural waters with particular respect to the accumulation of Sr-90 Pt. 2

    Kantor, D.; Szentjobi, O.


    The radioactive contamination of omnivorous fish species (Cyprinus carpio, Hypophtalmictys nobilis Richardson), of herbivorous fish species (Hypophtalmictys molitrix Valenciennes) and carnivorous fish species (Silurus glanis L., Esox Lucius L.) has been investigated. Orientative data have been obtained by analyzing samples originating from various sites. Though differences appeared between the analyzed samples, no incorporations of outstanding nature have been observed. In accordance with experiences described in literature, the isotope Sr-90 is accumulated in an increased degree in the skeleton of fish living in ponds. This is valid in all cases when the vital processes are regulated artificially by fishery methods. A particularly important factor is that the individual fish living in ponds are 2-3 or at most 4 years of age i.e. from the aspect of their ontogenesis their organism is in a strongly build-up phase. Sr-90 proved to be accumulated in a relatively greater amount in the organisms of herbivorous fish. (P.J.)

  8. Retention and removal 137Cs in Japanese catfish (Silurus asotus Linnaeus) in dressing and cooking method

    Malek, M.A.; Nakahara, N.; Nakamura, R.


    Japanese catfish contaminated by 137 Cs have been used to investigate how the dressing and cook-ing method affect the removal of radioactivity from the fish. During the dressing, 6.0% of the initial 137 Cs activity was removed by washing the live fish, further 30.3% of the activity relative to washed fish was removed by discarding the non-edible body parts (skeletons, fins, visceral mass, liver, kidney etc.) and washing the chopped fish. Fish curry was cooked using various spices, green-stuffs and vegetable oil following a method commonly used in South East and East Asian countries. The cooking process removed a further 61.6% of the 137 Cs activity relative to the activity in dressed fish. Taken together, this normal domestic fish dressing and culinary process removed 74.7% of the initial 137 Cs activity present in the live fish. During the cook-ing, the radioactivity removed from the fish pieces was found to distributed over the ingredients of the curry. The cooked fish pieces retained an average, 38.5% of the radioactivity present in the dressed raw fish pieces. Among the ingredients, the gravy was found to contain an average of 34.8% of the activity of the dressed fish. The activity in green-stuffs was found to vary from 4.0% (in cauliflower) to 7.2% (in potato). It may be concluded that normal home preparation and culinary processes removed the radio-activity from the fish to a great extent. In addition, discarding the gravy and green-stuffs of the curry further reduce the radioactivity intake into the human body. (author)


    Zoran Marinović


    Full Text Available On the basis of the data published between 1983 and 2008, this paper shows presence of tench (Tinca tinca, carp (Cyprinus carpio, pike (Esox lucius, catfish (Silurus glanis, zander (Sander lucioperca and sterlet (Acipenser ruthenus in the Gornje Podunavlje and Koviljsko-Petrovaradinski Rit Special Nature Reserves and the Begečka Jama Nature Park, as well as in the part of the Danube’s bed between river kilometre 1249- and 1255. The number of these fish species in the River Danube and its flood zones in this part of the Pannonian Basin is decreasing due to the use of inappropriate “tools”, electric current, uncontrolled agricultural and industrial waste dumps, degradation of the habitat. The above mentioned species deserve attention because, according to the Rulebook on declaration and protection of protected and strictly protected wild species of plants, animals and fungi of 2010, in Serbia, T. tinca is a strictly protected species, while C. carpio, E. lucius, S. glanis, S. lucioperca and A. ruthenus are listed as protected. On the basis of the 2009 Fisheries Law in Serbia, permanently closed fishing season was introduced for tench, and closed season in certain periods and fishing ban for individuals under the prescribed size for the rest of the above mentioned species. A. ruthenus is subject to the Law on Ratification of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES, ANNEX II and is listed in the category of species that may be in danger of extinction. Furthermore, it can be found on the IUCN Red List of Endangered Species of the International Union for Conservation of Nature – VU, which means that it is marked as vulnerable.

  10. Ostracism of an albino individual by a group of pigmented catfish.

    Ondřej Slavík

    Full Text Available Physiological and behavioural constraints hinder albino individuals. Albino animals are rare in the wild; this trait is associated with easy detection by predators, non-native or damaged environments, and exclusively aphotic environments in total darkness. The social aspect of albinism is reported only for human beings, and the effect is distinguishable in time and space when social benefits, are used to a limited the extent. Thus far, the social consequences of albinism for animals remain unknown. We used socially established groups of the pigmented catfish, (Silurus glanis, to observe space and temporal distance detachment of albino specimens in laboratory conditions. The albino fish were separated at larger distances from the group than pigmented individuals with the same social status determined by familiarity, and this asymmetry also varied in time. Albinism-related ostracism results in a solitary existence, usually followed by enhanced predation risk. The motivation for an individual's exclusion from a group appears to be the avoidance of the predation risk that increases not only for an odd individual but also for conspecifics within a group. Our findings indicate a role for albinism in behavioural processes related to sociality in a group of conspecifics.

  11. Can species-specific prey responses to chemical cues explain prey susceptibility to predation?

    Šmejkal, Marek; Ricard, Daniel; Sajdlová, Zuzana; Čech, Martin; Vejřík, Lukáš; Blabolil, Petr; Vejříková, Ivana; Prchalová, Marie; Vašek, Mojmír; Souza, Allan T; Brönmark, Christer; Peterka, Jiří


    The perception of danger represents an essential ability of prey for gaining an informational advantage over their natural enemies. Especially in complex environments or at night, animals strongly rely on chemoreception to avoid predators. The ability to recognize danger by chemical cues and subsequent adaptive responses to predation threats should generally increase prey survival. Recent findings suggest that European catfish ( Silurus glanis ) introduction induce changes in fish community and we tested whether the direction of change can be attributed to differences in chemical cue perception. We tested behavioral response to chemical cues using three species of freshwater fish common in European water: rudd ( Scardinius erythrophthalmus ), roach ( Rutilus rutilus ), and perch ( Perca fluviatilis ). Further, we conducted a prey selectivity experiment to evaluate the prey preferences of the European catfish. Roach exhibited the strongest reaction to chemical cues, rudd decreased use of refuge and perch did not alter any behavior in the experiment. These findings suggest that chemical cue perception might be behind community data change and we encourage collecting more community data of tested prey species before and after European catfish introduction to test the hypothesis. We conclude that used prey species can be used as a model species to verify whether chemical cue perception enhances prey survival.

  12. PSA-NCAM expression in the teleost optic tectum is related to ecological niche and use of vision in finding food.

    Labak, I; Pavić, V; Zjalić, M; Blažetić, S; Viljetić, B; Merdić, E; Heffer, M


    In this study, tangential migration and neuronal connectivity organization were analysed in the optic tectum of seven different teleosts through the expression of polysialylated neural cell adhesion molecule (PSA-NCAM) in response to ecological niche and use of vision. Reduced PSA-NCAM expression in rainbow trout Oncorhynchus mykiss optic tectum occurred in efferent layers, while in pike Esox lucius and zebrafish Danio rerio it occurred in afferent and efferent layers. Zander Sander lucioperca and European eel Anguilla anguilla had very low PSA-NCAM expression in all tectal layers except in the stratum marginale. Common carp Cyprinus carpio and wels catfish Silurus glanis had the same intensity of PSA-NCAM expression in all tectal layers. The optic tectum of all studied fishes was also a site of tangential migration with sustained PSA-NCAM and c-series ganglioside expression. Anti-c-series ganglioside immunoreactivity was observed in all tectal layers of all analysed fishes, even in layers where PSA-NCAM expression was reduced. Since the optic tectum is indispensable for visually guided prey capture, stabilization of synaptic contact and decrease of neurogenesis and tangential migration in the visual map are an expected adjustment to ecological niche. The authors hypothesize that this stabilization would probably be achieved by down-regulation of PSA-NCAM rather than c-series of ganglioside. © 2017 The Fisheries Society of the British Isles.

  13. Pumpkin seed cake as a fishmeal substitute in fish nutrition: effects on growth performance, morphological traits and fillet colour of two freshwater salmonids and two catfish species.

    Greiling, Alexander Michael; Schwarz, Christiane; Gierus, Martin; Rodehutscord, Markus


    The objectives of this study were to investigate the digestibility of pumpkin seed cake (PSC) for the rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), and effects on performance and product quality traits of four different fish species when PSC partially replaced fishmeal in extruded diets. A digestibility trial was carried out to determine apparent digestibility coefficients (ADC) for crude protein (CP), ether extract (EE) and gross energy (GE) of PSC fed to rainbow trout. In subsequent growth trials, effects on performance and morphological traits and fillet colour values of four different fish species [rainbow trout; brook trout, Salvelinus fontinalis (Mitchill, 1814); African sharptooth catfish, Clarias gariepinus (Burchell, 1822); and wels catfish, Silurus glanis (Linnaeus, 1758)] were evaluated when 60% of fishmeal protein of a reference diet was replaced by PSC protein (based on digestible CP). Nutrient ADC of PSC were high (CP: 89%, EE: 88% and GE: 84%). No significant effects on growth and only minor effects on fillet colour were detected in the trials. However, replacing fishmeal with PSC at the chosen level affected morphological traits and feed conversion in all four species to different extents. Replacement effects of PSC should be tested at lower levels of inclusion before conclusions are drawn on its suitability in fish diets.

  14. Trace elements concentrations in aquatic biota from the Iron Gates wetlands in Romania

    Matache M. L.


    Full Text Available Concentration of four heavy metals was studied in living organisms from the wetlands ecosystems within the Iron Gates Natural Park in Romania. Samples included aquatic plants (Ceratophyllum ssp., Potamogeton pectinatus, Potamogeton natans, molluscs (Sinanodonta woodiana, Unio tumidus, Unio pictorum and fish (Silurus glanis, Sander lucioperca, Aspius aspius, Cyprinus carpio, Carassius gibelio. Metals organotropism in fish samples (gills, liver, muscle, eggs has been studied (Kojadinovici et al., 2007; Foata et. Al, 2009; Dutton and Fisher, 2011; David et al., 2012. Metal contamination of the wetlandecosystems in the Iron Gates Natural Park has been documented in the past for sediments (Matache et. al, 2002 and soils (Matache et al., 2003. This is a consequence of the mining and quarrying activities performed in the Moldova Noua region between 1960’s and 2000’s. Zinc is the main metal contaminant in all categories of collected samples. For fish muscle tissue (part of the fish mainly consumed by the local inhabitants, comparison with EU standards has been performed. Issues related to human health appear especially for cadmium (EC, 2006. Potamogeton pectinatus is the least accumulating plant species, whilst Potamogeton natans and Ceratophyllum ssp. had shown similar accumulation capacities of the trace elements.

  15. Determination of 90Sr and 210Pb in freshwater fish in Austria

    Claudia Landstetter; Merita Sinojmeri; Christian Katzlberger; Arno Achatz


    A method for the determination of 90 Sr and 210 Pb in freshwater fish was developed. The determinations were conducted within a project on behalf of the Federal Ministry of Health. The aim of this project was to get an overview of the activity concentrations of natural and artificial radionuclides in freshwater fish in different lakes in Austria. For sampling the Neusiedler See in Burgenland, two lakes in Styria the Grundlsee and the Toplitz See, and the Zeller See in Salzburg were chosen. Chub (Leuciscus cephalus), pike (Esox lucius), perch (Perca fluviatilis), carp (Cyprinus carpio), catfish (Silurus glanis), pike-perch (Sander lucioperca) and burbot (Lota lota) were analysed. The samples were analysed using strontium specific extraction columns (Eichrom Industries Inc., TrisKem International) and liquid scintillation counting. In the edible parts of the fish samples (no fishbone) values of the activity concentration for 210 Pb varied between 0.009 ± 0.003 and 0.16 ± 0.04 Bq kg freshweight -1 and for 90 Sr between 0.010 ± 0.002 and 0.11 ± 0.02 Bq kg freshweight -1 . In this paper the method for the determination of 90 Sr and 210 Pb is described and the results are discussed. (author)

  16. The influence of environmental abiotic factors on the qualitative and quantitative structure of ichthyofauna from predeltaic Danube area

    Petronela Georgiana Calin Sandu


    Full Text Available The aim of the paper  is to analyse the influence of environmental factors on the capture and fish communities structure from Danube, between Siret River and Prut River mouth. Fish were collected from April to December 2012 in four fishing areas. During the year, 4910 kg, respectively 7121 fish of 31 species were collected. Cyprinidae, the dominant family, 54.84% in term of number of species, was represented by 17 species (Cyprinus carpio, Carassius gibelio, Barbus barbus, Abramis brama, Abramis sapa, Blicca bjoerkna, Leuciscus idus, Vimba vimba, Aspius aspius, Pelecus cultratus, Chondrostoma nasus, Ctenopharingodon idella, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Scardinius erythrophthalmus, Rutilus rutilus, Alburnus alburnus. Other families had the following structure: Percidae (16.13% with 5 species (Sander lucioperca, Zingel zingel, Zingel streber, Perca fluviatilis, Gymnocephalus schraetzer, Acipenseridae (12.90% with 4 species (Huso huso, Acipenser stellatus, Acipenser ruthenus, Acipenser gueldenstaedtii, Clupeidae (6.45% with two species (Alosa immaculata, Alosa tanaica, Siluridae (3.23% with one species (Silurus glanis, Esocidae (3.23% with one species (Esox lucius  and Salmonidae (3.23% with one species also (Salmo labrax. The highest capture was 2977.93 kg (60.65%, during the spring season (April-May, followed by autumn season (September–November, with 992.39 kg (20.21%. The water level and water flow showed high correlation with both number and total catch, respectively.

  17. How does agonistic behaviour differ in albino and pigmented fish?

    Ondřej Slavík


    Full Text Available In addition to hypopigmentation of the skin and red iris colouration, albino animals also display distinct physiological and behavioural alterations. However, information on the social interactions of albino animals is rare and has mostly been limited to specially bred strains of albino rodents and animals from unique environments in caves. Differentiating between the effects of albinism and domestication on behaviour in rodents can be difficult, and social behaviour in cave fish changes according to species-specific adaptations to conditions of permanent darkness. The agonistic behaviours of albino offspring of pigmented parents have yet to be described. In this study, we observed agonistic behaviour in albino and pigmented juvenile Silurus glanis catfish. We found that the total number of aggressive interactions was lower in albinos than in pigmented catfish. The distance between conspecifics was also analysed, and albinos showed a tendency towards greater separation from their same-coloured conspecifics compared with pigmented catfish. These results demonstrate that albinism can be associated with lower aggressiveness and with reduced shoaling behaviour preference, as demonstrated by a tendency towards greater separation of albinos from conspecifics.

  18. Radionuclides in biota collected near a dicalcium phosphate plant, southern Catalonia, Spain

    Mola, M.; Palomo, M.; Penalver, A.; Aguilar, C.; Borrull, F.


    Industrial waste containing radioactive U-decay series isotopes was released into the Ebro River, Spain, over a period of >20 years from a dicalcium phosphate (DCP) plant. This release raised activities of several natural radionuclides (e.g. 238 U, 234 U, 230 Th, 232 Th and 226 Ra) in biota taken from the area near the DCP plant. Plants and animals selected for this study included the green algae (Cladophora glomerata), the blue mussel (Mytilus edulis), the zebra mussel (Dreissena polymorpha) and the scavenger catfish (Silurus glanis) because they are all common in the area. Multiple sampling points were chosen for this study: (1) a site in the Riba-Roja Reservoir, above the DCP plant's area of influence, (2) four sites in the area surrounding the DCP plant, close to the town of Flix, and (3) a location in the Ebro Delta Estuary in Fangar Bay. Significant differences in the activities (in Bq kg -1 of dry weight) for the radioisotopes included in this study among samples were attributed to sample location and the species evaluated. For instance, relatively high activities for uranium and radium were obtained in algae collected around the DCP plant, compared to results obtained for algae samples taken from the unimpacted Riba-Roja Reservoir. In contrast, for zebra mussels, enhanced activities were observed for all radionuclides and, in particular, for thorium and radium isotopes within the area of influence. Among catfish samples, activity values from different locations were not significantly different, though slightly higher activities were observed at the sampling point just downstream of the DCP factory. (author)

  19. Fish remnants from the excavations of the Bronze Age barrow near Maryanskoe village (Dnepropetrovsk region, Ukraine

    O. M. Kovalchuk


    Full Text Available The Bronze Age mound (2.5–2.3 kya BC is located near the Maryanskoe village (Apostolovskyi district, Dnepropetrovsk region and was excavated in 1953. The results of determination of the fish remnants, which were found during the excavation, are presented in the paper. Eleven species belonging to 9 genera, 5 families and 5 orders (Acipenseriformes, Cypriniformes, Siluriformes, Esociformes, Perciformes were identified: russian sturgeon Acipenser gueldenstaedtii Brandt et Ratzeburg, 1833, stellate sturgeon A. stellatus Pallas, 1771, common ide Idus idus (Linnaeus, 1758, common roach Rutilus rutilus (Linnaeus, 1758, pontic roach R. frisii (Nordmann, 1840, common bream Abramis brama (Linnaeus, 1758, common carp Cyprinus carpio Linnaeus, 1758, tench Tinca tinca (Linnaeus, 1758, european catfish Silurus glanis Linnaeus, 1758, northern pike Esox lucius (Linnaeus, 1758, and zander Sander lucioperca (Linnaeus, 1758. Most of them are quite common in the Dnieper river basin. It was found that carp fishes predominate in the number of species. Most of the bone remnants in the collection belong to zander, catfish and pike, while common roach, pontic roach and common bream are identified by the few bones. This may indicate a different role of these species in the diet of the local population. The ratio of skeletal elements in the collection is the evidence of the fish cutting on the site. Body length and weight was reconstructed for 64 fish specimens. It was found that they were mature and small-sized, except for catfish, pike and perch. Taking into account the characteristics of the funeral rituals of the Yamna culture population, fish bones from the mound near Maryanskoe can be remnants of the parting meal.


    N. Ja. Rudik-Leuska


    authorities should focus attention on their protection and restoration of abundance. Keywords: Sulinsky Reserve, Sula Bay, conservation lists, sterlet (Acipenser ruthenus L., Crucian carp (Carassius carassius L., Common dace (Leuciscus leuciscus L., Wels catfish (Silurus glanis L., Asp (Aspius aspius L., Bitterling (Rhodeus sericeus Pall., Spined loach (Cobitis taenia L..

  1. Detection of toxic effects of Cd{sup 2+} on different fish species via liver cytochrome P450-dependent monooxygenase activities and FTIR spectroscopy

    Henczova, Maria; Deer, Aranka Kiss [University of Szeged, Department of Biochemistry, P.O. Box 533, Szeged (Hungary); Komlosi, Viktoria [Chemical Research Center of the Hungarian Academy of Sciences, Department of Molecular Spectroscopy, P.O. Box 17, Budapest (Hungary); Mink, Janos [Chemical Research Center of the Hungarian Academy of Sciences, Department of Molecular Spectroscopy, P.O. Box 17, Budapest (Hungary); University of Veszprem, Faculty of Information Technology, Research Institute of Chemistry and Process Engineering; Analytical Chemistry Research Group of the Hungarian Academy of Sciences, P.O. Box 158, Veszprem (Hungary)


    The in vivo and in vitro effects of Cd{sup 2+} and the CYP1A inductor {beta}-naphthoflavone({beta}-NF) on the hepatic cytochrome P450 (Cyt 450) monooxygenases were studied in silver carp (Hypophthalmichtys molitrix V.), wels (Silurus glanis L.), and carp (Cyprinus carpio). In vivo treatment of carp with a high dose of Cd{sup 2+} (10 mg kg{sup -1}, for 3 days) caused a strong inhibition of 7-ethoxyresorufin-O-deethylase (EROD) and a lower inhibition of 7-ethoxycoumarin-O-deethylase (ECOD) activity. The low-dose cadmium treatment (2 mg kg{sup -1} Cd{sup 2+}, for 6+3 days) resulted in 4-fold increase in EROD and a 3-fold increase in ECOD activity. The combined treatment with Cd{sup 2+} and {beta}-NF in both cases led to a loss of EROD inducibility. The silver carp and wels were treated with 10 mg L{sup -1} Cd{sup 2+} for 72 h in water. The Cyt P450 content in the wels liver microsomes was increased significantly after treatment for 48 h, whereas there was only a slight, not significant increase in Cyt P450 content in the silver carp microsomes. While the Cd{sup 2+} treatment resulted in inhibition of the CYP1A isoenzymes (EROD and ECOD), the APND (aminopyrene-N-demethylase, CYP2B or CYP3A isoenzyme) activity was increased 3- to 4-fold in both fish species. In vitro experiments of the effect of Cd{sup 2+} led to a concentration-dependent inhibition in all three investigated fish species. The ECOD isoenzyme of silver carp was the most sensitive to Cd{sup 2+}. The lowest concentration of Cd{sup 2+} resulted in 50% inhibition. The APND isoenzyme was similarly sensitive to Cd{sup 2+} in all three investigated fish species. The most sensitive species was the wels, and the least sensitive were the carp isoenzyme. FTIR spectroscopy confirmed that cadmium caused damage to the protein structure. These results support the enzyme activity measurements measured in vivo and in vitro. (orig.)

  2. Susceptibility of pike Esox lucius to a panel of Ranavirus isolates

    Jensen, Ann Britt Bang; Ersbøll, A. K.; Ariel, Ellen


    In order to study the pathogenicity of ranaviruses to a wild European freshwater fish species, pike Esox lucius fry were challenged with the following Ranavirus isolates: epizootic haematopoietic necrosis virus (EHNV), European sheatfish virus (ESV), European catfish virus (ECV), pike-perch irido......In order to study the pathogenicity of ranaviruses to a wild European freshwater fish species, pike Esox lucius fry were challenged with the following Ranavirus isolates: epizootic haematopoietic necrosis virus (EHNV), European sheatfish virus (ESV), European catfish virus (ECV), pike...

  3. Marmara gölü balık faunası ve balıkçılık faaliyetleri.

    Ali İlhan


    Full Text Available Bu çalışma, Mart 2012-Şubat 2013 tarihleri arasında Marmara Gölü balık faunasının ve göldeki balıkçılık faaliyetlerinin günümüzdeki durumunu ortaya çıkarmak amacıyla gerçekleştirilmiştir. Balık örneklemeleri, gölün doğu, orta ve batı kesiminde belirlenen 3 farklı istasyonda gerçekleştirilmiştir. Balık avcılığında, fanyalı ve fanyasız ağlar ile kerevit pinterleri kullanılmıştır. Söz konusu ağ ve pinterlerin suda kalma süreleri mevsimsel şartlara göre küçük değişiklikler gösterse de yaklaşık olarak 12 saattir. İstasyonlar arası homojeniteyi sağlamak amacıyla her istasyonda aynı özellikteki ağlar ve pinterler kullanılmıştır. Ayrıca, kıyısal bölgede küçük boylu türlerin ve diğer türlerin juvenillerinin yakalanması için tül ığrıp kullanılmıştır. Araştırma sonucunda gölde Atherinidae, Cyprinidae, Cobitidae, Percidae, Poecilidae ve Gobiidae familyalarına ait 15 takson tespit edilmiştir. Gölün son on yıllık balıkçılık verileri incelendiğinde en önemli ticari türün Sazan (Cyprinus carpio olduğu, bunu sudak (Sander lucioperca, yayın (Silurus glanis ve tatlısu kolyozu (Alburnus battalgilae’nun izlediği belirlenmiştir. Ayrıca, her ne kadar ticari değeri diğerleri kadar yüksek olmasa da üretim miktarı açısından gümüşi havuz balığı (Carassius gibelio’nın da gölde önemli derecede yer aldığı saptanmıştır

  4. Quantitation of ranaviruses in cell culture and tissue samples

    Holopainen, Riikka; Honkanen, Jarno; Jensen, Britt Bang


    ; European sheatfish virus, ESV; Frog virus 3, FV3; Bohle iridovirus, BIV; Doctor fish virus, DFV; Guppy virus 6, GV6; Pike-perch iridovirus, PPIV; Rana esculenta virus Italy 282/I02, REV282/I02 and Short-finned eel ranavirus, SERV) were detected with the qPCR assay. In addition, two fish cell lines...

  5. Susceptibility of pike-perch Sander lucioperca to a panel of ranavirus isolates

    Jensen, Britt Bang; Holopainen, Riikka; Tapiovaara, Hannele


    The host range of ranaviruses was investigated by challenging pike-perch (Sander lucioperca) with the following ranavirus isolates: epizootic haematopoietic necrosis virus (EHNV), European sheatfish virus (ESV), European catfish virus (ECV), pike-perch iridovirus (PPIV), short-finned eel virus...

  6. Journal of Biosciences | Indian Academy of Sciences

    Genetic similarity and diversity of cultured catfish Silurus asotus populations collected from two areas in western Korea were examined using randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). Out of 20 random primers tested, 5 produced 1344 RAPD bands ranging from 8.2 to 13.6 polymorphic ...

  7. Propagation and isolation of ranaviruses in cell culture

    Ariel, Ellen; Nicolajsen, Nicole; Christophersen, Maj-Britt


    The optimal in vitro propagation procedure for a panel of ranavirus isolates and the best method for isolation of Epizootic haematopoietic necrosis virus (EHNV) from organ material in cell-culture were investigated. The panel of ranavirus isolates included: Frog virus 3 (FV3), Bohle iridovirus (BIV......), Pike-perch iridovirus (PPIV), European catfish virus (ECV), European sheatfish virus (ESV), EHNV, Doctor fish virus (DFV), Guppy virus 6 (GF6), short-finned eel virus (SERV) and Rana esculenta virus Italy 282/102 (REV 282/102). Each isolate was titrated in five cell lines: bluegill fry (BF-2......), epithelioma papulosum cyprini (EPC), chinook salmon embryo (CHSE-214) rainbow trout gonad (RTG-2) and fathead minnow (FHM), and incubated at 10, 15, 20, 24 and 28 °C for two weeks. BF-2, EPC and CHSE-214 cells performed well and titers obtained in the three cell lines were similar, whereas FHM and RTG-2 cells...

  8. Comparative analysis of sequences from PT 2013

    Mikkelsen, Susie Sommer

    Sheatfish and not EHNV. Generally, mistakes occurred at the ends of the sequences. This can be due to several factors. One is that the sequence has not been trimmed of the sequence primer sites. Another is the lack of quality control of the chromatogram. Finally, sequencing in just one direction can result...... diseases in Europe. As part of the EURL proficiency test for fish diseases it is required to sequence any RANA virus isolates found in any of the samples. It is also highly recommended to sequence the ISA virus to determine whether it be HPRΔ or HPR0. Furthermore, it is recommended that any VHSV and IHNV...... isolates be genotyped. As part of the evaluation of the proficiency results it was decided this year to look into the quality and similarity of the sequence results for selected viruses. Ampoule III in the proficiency test 2013 contained an EHNV isolate. The EURL received 43 sequences from 41 laboratories...


    Agus Djoko Utomo


    “Danau lindung Empangau “ (124 ha di Kapuas Hulu Kalimantan Barat terdapat stok ikan 5.700 ekor/ha didominansi oleh ikan Haruan (Channa striata, Entukan (Thynnichthys thynnoides, Biawan (Helostoma temmenckii, Tengadak (Barbonymus schwanenfeldii. Suaka perikanan tipe sungai “Kapak Hulu” (segmen sungai panjang 1 km, lebar 30 m di Lubuk Lamam Sumatera selatan terdapatstok ikan 4 ton didominansi oleh ikan Lais (Kryptopterus kryptopterus, Baung (Hemibagrus nemurus, Palau (Osteochilus hasselti, Lampam (Barbonymus schwanenfeldii. Suaka perikanan “Lubuk Gunung Isam” di Lubuk Lamam Sumatera selatan terdapat stok ikan 2 ton didominansi oleh ikan Tapa (Wallago leeri, Bulu Tulang (Kryptopterus apagon, Baung (Hemibagrus nemurus, Lais (Kryptopterus kryptopterus. Agar supaya suaka perikanan dapat berfungsi dengan baik sehingga mempunyai dampak terhadap masyarakat sekitarnya maka suaka tersebut harus dikelola dengan tepat mulai dari penentuan lokasi yang tepat, sarana prasarana yang diperlukan, serta kelembagaan dan pengawasan. Floodplain waters are strongly influenced by season, drought during dry season and floods in rainy season. There are two groups of fish in the swamp namely the swamp fishgroup (black fish and river fish group (white fish. Based on the type of habitat in the swamp flood, there are several types of fish reserves namely floodplain pool reserve, swamp lake reserve, river segment reserve, and deep pool of the riverreserve. Floodplain pool reserve type:” Suak Buaya Reserve”(0.5 ha in southern Sumatra contained 2 tons of fish stocks dominated by snakehead, kissing gourami, Snakeskin gourami, climbing perches. Swamp lake reserve type: Empangau Lake Reserve (124 ha in West Kalimantan with5.700 fish/ha dominated by Snakehead fish, minnows or carp,kissing gourami, Tinfoil barb. River segment reserve type: “Kapak Hulu Reserve “ (river segment, length =1 km and width =30 m in southern Sumatra contained 4 tons of fish dominated by Sheatfishes, Catfish

  10. Identification And Study Of Fish Species In Karkheh River (Iran

    Khoshnood Zahra


    Full Text Available For the investigation of fish from Karkheh River, sampling was performed in a six month period from August 2014 to January 2015. All sampled fish were measured for biometrical values (length and weight. General results of the sampling and identification of the fish showed the presence of 14 species from four fish families of Cyprinidae, Mugilidae, Siluridae and Macrostomidae, out of which the Cyprinidae family were the most frequent of the sampled fish. The most significant abundance belongs to Cyprinus carpio. The fish sampled in the present study were: Liza abu, Ctenopharyngodon idella, Barbel sp., Cyprinion macrostomum, Barbus sharpeyi, Hypophthalmichthys molitrix, Barbus esocinus, Barbus barbulus, Barbus luteus, Barbus grypus, Cyprinus carpio, Silurus triostegus, Mastacembelus circumcinctus and Capoeta trutta. Shannon Index results showed that the fish biodiversity in the studyed area followed a uniform path and additionally that the considered area at the studied period has good fish biodiversity.

  11. [Influence of 175-m-impoundment in Three Gorges Reservoir area on the food web energy sources of main commercial fishes in backwater area of xiaojiang River].

    Li, Bin; Wang, Zhi-Jian; Yue, Xing-Jian; Wang, Yong-Ming; Jin, Li; Zhang, Yao-Guang


    The impoundment in the Three Gorges Reservoir Area (TGRA) was first reached 175 m in 2010. To approach the influence of this impoundment on the food web energy sources of fishes in the tributaries of TRGA, an analysis was made on the food web energy sources of seven economically important fishes (Carassius auratus, Cyprinus carpio, Silurus asotus, Culter mongolicus mongolicus, Mystus macropterus, Pelteobagrus vachelli, and Pelteobagrus nitidus) in the backwater area of Xiaojiang River by using stable isotope method in combining with IsoSource Model. The results showed that before this impoundment (July 2010), microalgae were the main energy sources for the seven species. After this impoundment (December 2010), the contribution ratio of the microalgae decreased somewhat, while the relative contribution of terrestrial C4 plants had an obvious increase. Especially for crucian carp (C. auratus) and catfish (S. asotus), the contribution rate of the C4 plants reached 38-54% and 32-50%, respectively. After the impoundment, at least 30% of the energy resources of these two fishes were come from terrestrial C4 plants, suggesting that the impoundment in TGRA increased the contribution rate of exogenous terrestrial C4 plants as the energy sources of fishes.

  12. Effects of Dietary Supplementation of Magnesium Hydrogen Phosphate (MgHPO as an Alternative Phosphorus Source on Growth and Feed Utilization of Juvenile Far Eastern Catfish (

    Tae-Hyun Yoon


    Full Text Available The present study was conducted to investigate a supplemental effect of magnesium hydrogen phosphate (MHP, MgHPO4 as an alternative phosphorus (P source on growth and feed utilization of juvenile far eastern catfish (Silurus asotus in comparison with three conventional P additives (monocalcium phosphate (MCP, dicalcium phosphate (DCP and tricalcium phosphate [TCP] as positive controls. A basal diet as a negative control was prepared without P supplementation and four supplemental P sources were added at the level of 2%. Five groups of 450 fish having mean body weight of 11.3 g following 24 h fasting after three week adaptation period were randomly distributed into each of 15 tanks (30 fish/tank. Fish were hand-fed to apparent satiety twice a day for 8 weeks. Fish fed MHP had weight gain (WG, protein efficiency ratio and specific growth rate comparable to those fed MCP. Fish fed MHP and MCP had feed efficiency (FE significantly higher (p0.05 among treatments. Fish fed control had the lowest hematocrit, which was significantly different (p<0.05 from that of fish fed MHP. Fish fed MCP and MHP had plasma P higher (p<0.05 than fish fed the other diets. Relative efficiencies of MCP, DCP and TCP to MHP were found to be 100.5 and 101.3%, 92.0 and 91.6%, and 79.1 and 80.9% for WG and FE, respectively. P availability was determined to be 88.1%, 75.2%, 8.7%, and 90.9% for MCP, DCP, TCP, and MHP, respectively. Consequently, MHP recovered from wastewater stream showed that as an alternative P source its performance was comparative with MCP on growth and feed utilization of juvenile far eastern catfish.

  13. Thermal processing of food reduces gut microbiota diversity of the host and triggers adaptation of the microbiota: evidence from two vertebrates.

    Zhang, Zhimin; Li, Dapeng


    Adoption of thermal processing of the diet drives human evolution and gut microbiota diversity changes in a dietary habit-dependent manner. However, whether thermal processing of food triggers gut microbial variation remains unknown. Herein, we compared the microbiota of non-thermally processed and thermally processed food (NF and TF) and investigated gut microbiota associated with NF and TF in catfish Silurus meridionalis and C57BL/6 mice to assess effects of thermal processing of food on gut microbiota and to further identify the differences in host responses. We found no differences in overall microbial composition and structure in the pairwise NF and TF, but identified differential microbial communities between food and gut. Both fish and mice fed TF had significantly lower gut microbial diversity than those fed NF. Moreover, thermal processing of food triggered the changes in their microbial communities. Comparative host studies further indicated host species determined gut microbial assemblies, even if fed with the same food. Fusobacteria was the most abundant phylum in the fish, and Bacteroidetes and Firmicutes dominated in the mice. Besides the consistent reduction of Bacteroidetes and the balanced Protebacteria, the response of other dominated gut microbiota in the fish and mice to TF was taxonomically opposite at the phylum level, and those further found at the genus level. Our results reveal that thermal processing of food strongly contributes to the reduction of gut microbial diversity and differentially drives microbial alterations in a host-dependent manner, suggesting specific adaptations of host-gut microbiota in vertebrates responding to thermal processing of food. These findings open a window of opportunity to understand the decline in gut microbial diversity and the community variation in human evolution and provide new insights into the host-specific microbial assemblages associated with the use of processing techniques in food preparation in

  14. Host Age Affects the Development of Southern Catfish Gut Bacterial Community Divergent From That in the Food and Rearing Water.

    Zhang, Zhimin; Li, Dapeng; Refaey, Mohamed M; Xu, Weitong; Tang, Rong; Li, Li


    Host development influences gut microbial assemblies that may be confounded partly by dietary shifts and the changing environmental microbiota during ontogenesis. However, little is known about microbial colonization by excluding dietary effects and compositional differences in microbiota between the gut and environment at different ontogenetic stages. Herein, a developmental gut microbial experiment under controlled laboratory conditions was conducted with carnivorous southern catfish Silurus meridionalis fed on an identical prey with commensal and abundant microbiota. In this study, we provided a long-term analysis of gut microbiota associated with host age at 8, 18, 35, 65, and 125 day post-fertilization (dpf) and explored microbial relationships among host, food and water environment at 8, 35, and 125 dpf. The results showed that gut microbial diversity in southern catfish tended to increase linearly as host aged. Gut microbiota underwent significant temporal shifts despite similar microbial communities in food and rearing water during the host development and dramatically differed from the environmental microbiota. At the compositional abundance, Tenericute s and Fusobacteria were enriched in the gut and markedly varied with host age, whereas Spirochaetes and Bacteroidetes detected were persistently the most abundant phyla in food and water, respectively. In addition to alterations in individual microbial taxa, the individual differences in gut microbiota were at a lower level at the early stages than at the late stages and in which gut microbiota reached a stable status, suggesting the course of microbial successions. These results indicate that host development fundamentally shapes a key transition in microbial community structure, which is independent of dietary effects. In addition, the dominant taxa residing in the gut do not share their niche habitats with the abundant microbiota in the surrounding environment. It's inferred that complex gut microbiota

  15. Digestive and locomotor capacity show opposing responses to changing food availability in an ambush predatory fish.

    Fu, Shi-Jian; Peng, Jing; Killen, Shaun S


    Metabolic rates vary widely within species, but little is known about how variation in the 'floor' [i.e. standard metabolic rate (SMR) in ectotherms] and 'ceiling' [maximum metabolic rate (MMR)] for an individual's aerobic scope (AS) are linked with digestive and locomotor function. Any links among metabolic traits and aspects of physiological performance may also be modulated by fluctuations in food availability. This study followed changes in SMR, MMR, and digestive and locomotor capacity in southern catfish ( Silurus meridionalis ) throughout 15 days of food deprivation and 15 days of refeeding. Individuals downregulated SMR during food deprivation and showed only a 10% body mass decrease during this time. Whereas critical swim speed ( U crit ) was robust to food deprivation, digestive function decreased after fasting with a reduced peak oxygen uptake during specific dynamic action (SDA) and prolonged SDA duration. During refeeding, individuals displayed rapid growth and digestive function recovered to pre-fasting levels. However, refed fish showed a lower U crit than would be expected for their increased body length and in comparison to measures at the start of the study. Reduced swimming ability may be a consequence of compensatory growth: growth rate was negatively correlated with changes in U crit during refeeding. Southern catfish downregulate digestive function to reduce energy expenditure during food deprivation, but regain digestive capacity during refeeding, potentially at the cost of decreased swimming performance. The plasticity of maintenance requirements suggests that SMR is a key fitness trait for in this ambush predator. Shifts in trait correlations with food availability suggest that the potential for correlated selection may depend on context. © 2018. Published by The Company of Biologists Ltd.

  16. Optimal Incorporation Level of Dietary Alternative Phosphate (MgHPO and Requirement for Phosphorus in Juvenile Far Eastern Catfish (

    Tae-Hyun Yoon


    Full Text Available A growth trial was conducted to determine the optimal incorporation level of dietary magnesium hydrogen phosphate (MHP, MgHPO4, which was manufactured from swine manure and phosphorus (P, required by juvenile far eastern catfish (Silurus asotus. Graded MHP of 0.5%, 1.0%, 1.5%, and 2.0%, and 2.0% monocalcium phosphate (MCP each was added to the basal diet (control in lieu of cellulose to become the range of available P (AP from 0.4% to 0.8% of which diets were designated as control, MHP0.5, MHP1.0, MHP1.5, MHP2.0, and MCP, respectively. Control diet contained fish meal (20%, soybean meal (40%, wheat flour (27%, corn gluten meal (5%, fish oil (2% and soy oil (2% as main ingredients. Following a 24 h fasting, 540 fish with a mean body weight of 11.8 g were randomly allotted to 6 groups in triplicate, whereby 18 tanks (0.4×0.6×0.36 cm, water volume of 66 L were prepared. The feeding experiment lasted for 8 weeks. Fish group fed the control diet showed the lowest weight gain (WG and feed efficiency (FE among treatments. The WG was, however, not significantly different (p>0.05 from that of fish group fed MHP0.5. Fish group fed MHP2.0 showed the highest WG and FE of which values were not significantly different from those of fish groups fed diets MHP1.0 and MHP1.5 as well as MCP (p>0.05 except fish groups fed control and MHP0.5. Aspartate aminotransferase was significantly decreased with an increase in available P, while alanine aminotransferase did not show a significant difference among treatment. The highest inorganic P in plasma was observed in fish fed MHP2.0. From the present results, a second-order regression analysis revealed that the optimal dietary MHP level and the AP requirement were found to be 1.62% and 0.7%, respectively.