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Sample records for toxorhynchites rutilus rutilus

  1. Laboratory and field studies with /sup 32/P labeled Toxorhynchites rutilus rutilus

    SciTech Connect

    Smittle, B.J.; Focks, D.A.

    1986-12-01

    Females and eggs of Toxorhynchites r. rutilus were labeled with /sup 32/P by feeding fourth-stage larvae /sup 32/P labeled Aedes aegypti larvae. Eggs from females up to 3 weeks in age had detectable levels of radioactivity and individual eggs contained ca. 0.3% of the mother's total radioactivity. Comparisons of labeled and unlabeled females in indoor and outdoor cage tests indicated that survival and fecundity of the 2 groups were approximately equal. No differences were noted for dispersal and fecundity of labeled and control females released in field tests. The /sup 32/P-labeled Tx. r. rutilus females behave similarly to unlabeled females, and this method of radiolabeling provides a sound tool for tracking laboratory-reared females released into an area with an indigenous population.

  2. Cell types in the pituitary of the roach, Rutilus rutilus (L.), (Teleostei).

    PubMed Central

    Jafri, S I; Ensor, D M

    1980-01-01

    The pituitary of roach, Rutilus rutilus (L.), is pear-shaped and situated in the sella turcica. It is characterised by a large pars nervosa, which penetrates deep into the other regions, splitting the proximal pars distalis. Spatial localisation of nerve fibre types and glandular cell types occurs. Using a variety of staining techniques six glandular cell types have been localised and their distribution is disucssed in relation to those of the other teleost pituitaries. PMID:6159340

  3. Trophic flexibility by roach Rutilus rutilus in novel habitats facilitates rapid growth and invasion success.

    PubMed

    Hayden, B; Massa-Gallucci, A; Harrod, C; O'grady, M; Caffrey, J; Kelly-Quinn, M

    2014-04-01

    Stable isotope and gut content analyses, in conjunction with backcalculated length-at-age estimates of growth, were employed to examine the relationship between trophic ecology and growth rate of a successful invader, Rutilus rutilus, in eight lakes in Ireland. The data revealed that R. rutilus was a trophic generalist in Irish lakes. It utilized a greater proportion of pelagic resources in mesotrophic lakes than in eutrophic lakes, potentially due to a greater density of benthic macroinvertebrates in eutrophic systems. The species was characterized by a large dietary and isotopic niche width and high temporal and spatial variations in diet. Growth rates were typical of those found in the native range of the species and were unrelated to either lake productivity or fish's diet. A generalist trophic ecology confers significant advantages on an invasive species, allowing it to exploit a variety of novel resources and fluctuations in prey availability. PMID:24628030

  4. Evidence of altered fertility in female roach (Rutilus rutilus) from the River Seine (France).

    PubMed

    Gerbron, M; Geraudie, P; Fernandes, D; Rotchell, J M; Porte, C; Minier, C

    2014-08-01

    A large variety of anthropogenic chemicals present in the aquatic environment have been shown to be able to alter the endocrine system of exposed organisms, potentially impacting their reproductive function. The aim of this study was to assess the effects of environmental pollution on the reproductive system of wild female roach (Rutilus rutilus) from the Seine River (Normandy, France). A suite of biomarkers of endocrine disruption including gonado-somatic index, plasmatic vitellogenin, gonadal aromatase activity and histological parameters (oocyte diameter and gonad maturation) were studied. Female fish from the polluted sites showed a number of reproductive alterations, including inhibited gonad maturation, reduced oocyte growth, reduced levels of plasmatic vitellogenin and 3-fold lower gonadal aromatase activity than females collected in the reference site. Overall, these results highlight the presence of endocrine disruption in female roach from the Seine River. PMID:24811946

  5. Characterizing the transcriptome and molecular markers information for roach, Rutilus rutilus.

    PubMed

    Chi, Wei; Ma, Xufa; Niu, Jiangong; Zou, Ming

    2016-03-01

    Rutilus rutilus (roach) is native to most of Europe and western Asia, and the Irtysh River basin in Sinkiang, northwest China is the marginal area of their natural distribution. The wide distribution and unique characteristic of this species makes it an ideal model for analysing ecological and comparative genomics. However, the limited genome sequences available for this species have hindered these investigations. Transcriptomes from the brains and livers of five individuals collected from the Irtysh River basin were sequenced using Illumina paired-end sequencing technology. A collection of 132,289 unigenes for this species were obtained using a de novo assembly method based on nearly 120 million clean reads encompassing more than 14 Gb data. Approximately 37.5% (49,656), 27.1% (35,867) and 21.2% (27,987) of the transcriptome had homologues deposited in Nt, Nr and Swiss-Prot, respectively; 12.3% (16,328) were assigned to eukaryotic orthologous groups of proteins classifications, and 21.5% (28,429) harboured Interpro domains. On the basis of the assembled transcriptome, we detected 177,493 single-nuc leotide variation resident in 39.3% (52,029) of the sequences and 20.8% (27,497) of the sequences harbouring 36,639 simple sequence repeats. The identified molecular markers are a basis for further ecological analysis, and the transcriptome reported here allows for more extensive evolutionary analyses of the Cyprinidae, the most species-rich family of freshwater fishes. PMID:27019431

  6. In vitro and in vivo studies of the endocrine disrupting potency of cadmium in roach (Rutilus rutilus) liver.

    PubMed

    Gerbron, M; Geraudie, P; Xuereb, B; Marie, S; Minier, C

    2015-06-30

    Cadmium has been reported to exert estrogenic, antiestrogenic or both effects in vertebrate species. To elucidate the endocrine disrupting action of CdCl2, ex vivo and in vivo experiments were performed in roach (Rutilus rutilus). Roach liver explants were exposed to a range of CdCl2 concentrations alone (0.1-50?M) or with an effective concentration (100nM) of 17?-estradiol (E2). In addition, juvenile roach were intraperitoneally injected with CdCl2 (0.1-2.5mg/kg) with or without 1mg E2/kg. Subsequent analysis evaluated the effect of CdCl2 on vitellogenin (VTG) synthesis both at the mRNA and protein level, on estrogen receptors (er? and er?1) and on androgen receptor (ar) mRNA expression. Ex vivo and in vivo experiments indicated that CdCl2 is strongly anti-estrogenic as, when co-exposed to E2, CdCl2 significantly inhibited VTG production as well as vtg and er? mRNA expressions. Moreover, CdCl2 compromised the E2-mediated induction of the ar mRNA expression in vivo. PMID:26024563

  7. Metabolomics Reveals Target and Off-Target Toxicities of a Model Organophosphate Pesticide to Roach (Rutilus rutilus): Implications for Biomonitoring

    PubMed Central

    2011-01-01

    The ability of targeted and nontargeted metabolomics to discover chronic ecotoxicological effects is largely unexplored. Fenitrothion, an organophosphate pesticide, is categorized as a red list pollutant, being particularly hazardous to aquatic life. It acts primarily as a cholinesterase inhibitor, but evidence suggests it can also act as an androgen receptor antagonist. Whole-organism fenitrothion-induced toxicity is well-established, but information regarding target and off-target molecular toxicities is limited. Here we study the molecular responses of male roach (Rutilus rutilus) exposed to fenitrothion, including environmentally realistic concentrations, for 28 days. Acetylcholine was assessed in brain; steroid metabolism was measured in testes and plasma; and NMR and mass spectrometry-based metabolomics were conducted on testes and liver to discover off-target toxicity. O-demethylation was confirmed as a major route of pesticide degradation. Fenitrothion significantly depleted acetylcholine, confirming its primary mode of action, and 11-ketotestosterone in plasma and cortisone in testes, showing disruption of steroid metabolism. Metabolomics revealed significant perturbations to the hepatic phosphagen system and previously undocumented effects on phenylalanine metabolism in liver and testes. On the basis of several unexpected molecular responses that were opposite to the anticipated acute toxicity, we propose that chronic pesticide exposure induces an adapting phenotype in roach, which may have considerable implications for interpreting molecular biomarker responses in field-sampled fish. PMID:21410251

  8. Effects of Exposure to WwTW Effluents over Two Generations on Sexual Development and Breeding in Roach Rutilus rutilus.

    PubMed

    Hamilton, Patrick B; Lange, Anke; Nicol, Elizabeth; Bickley, Lisa K; De-Bastos, Eliane S R; Jobling, Susan; Tyler, Charles R

    2015-11-01

    Exposure to environmental estrogens in wastewater treatment works (WwTW) effluents induces feminized responses in male fish, including the development of eggs in male testes. However, the impacts on the offspring of exposed fish are not well understood. In this study, we examined whether roach (Rutilus rutilus) from mothers that had been exposed to an undiluted WwTW effluent from early life to sexual maturity had altered susceptibility to gonadal feminization and an impaired capacity to reproduce. For males from both WwTW effluent exposed mothers and dilution water exposed mothers, effluent exposure for up to 3 years and 9 months induced feminized male gonads, although the intersex condition was relatively mild. There was no difference in the severity of gonadal feminization in roach derived from either WwTW effluent exposed or dilution water exposed mothers. Furthermore, a breeding study revealed that roach with effluent-exposed mothers reproduced with an equal success as roach with mothers exposed to clean water. Roach exposed to the effluent for 3 years in this study were able to reproduce successfully. Our findings provide no evidence for impacts of WwTW effluent exposure on reproduction or gonadal disruption in roach down the female germ line and add to existing evidence that male roach with a mild intersex condition are able to breed competitively. PMID:26440068

  9. Chronic exposure of Rutilus rutilus caspicus fingerlings to ambient copper: Effects on food intake, growth performance, biochemistry and stress resistance.

    PubMed

    Hoseini, Seyyed Morteza; Rajabiesterabadi, Hamid; Kordrostami, Sara

    2016-02-01

    An 8-week trial was conducted to investigate the effect of ambient copper (Cu) on growth performance, physiological characteristics and stress resistance of Caspian roach, Rutilus rutilus caspicus. Fish were exposed to 0 (control), 0.02, 0.04 and 0.06 ppm Cu, and their food intake and growth performance were fortnightly recorded. Also, serum cortisol, glucose, alanine aminotransferase (ALT) and sodium (Na) levels were determined after 2 and 8 weeks exposure to ambient Cu. At the end of trial, serum total protein, albumin, globulin and albumin-globulin ratio (A:G) levels, whole body proximate composition and stress tolerance of the fish were measured. Results showed that Cu exposure resulted in a significant suppression in food intake after 2 weeks, which was eliminated after 4 weeks in 0.02 ppm groups and after 6 weeks in 0.04 and 0.06 ppm groups. Cu exposure brought about an inferior growth that recovered in line with the experiment progression, following a dose-dependent manner. Cu-exposed fish showed a dose-dependent increase in serum cortisol, glucose and ALT as well as decrease in serum Na, after 2 weeks. These parameters showed a full recovery in 0.02 ppm group and a partial recovery in 0.04 and 0.06 ppm groups, at the 8th week. Significant suppression in serum total protein, albumin, globulin and A:G levels and whole body dry matter, lipid and protein levels as well as stress resistance was observed in 0.04 and 0.06 ppm groups. It is concluded that Cu exposure could adversely affect growth performance, physiological characteristics and stress resistance of Caspian roach, which might affect its ecological features. PMID:24105068

  10. Differential habitat use and antipredator response of juvenile roach (Rutilus rutilus) to olfactory and visual cues from multiple predators.

    PubMed

    Martin, Charles W; Fodrie, F Joel; Heck, Kenneth L; Mattila, Johanna

    2010-04-01

    The indirect, behavioral effects of predation and predator-predator interactions can significantly alter the trophic ecology of many communities. In numerous instances, the strength of these effects may be determined by the ability of prey to identify predation risk through predator-specific cues and respond accordingly to avoid capture. We exposed juvenile roach (Rutilus rutilus), a common forage fish in many brackish and freshwater environments, to vision and/or olfactory cues from two predators with different hunting methods: northern pike (Esox lucius, an ambush predator) and European perch (Perca fluviatilis, a roving predator). Our results demonstrated that responses of roach to perceived risk (as evidenced by their selection of structured or open-water habitats) were highly dependent on cue type and predator identity. For instance, roach responded to olfactory cues of pike by entering open-water habitat, but entered structured habitat when presented with a vision cue of this predator. Opposite responses were elicited from roach for both olfactory and visual cues of perch. Interestingly, roach defaulted to selection of structured habitat when presented with vision + olfaction cues of either predator. Moreover, when presented individual cues of both predators together, roach responded by choosing open-water habitat. Upon being presented with vision + olfaction cues of both predators, however, roach strongly favored structured habitat. Differences in habitat selection of roach were likely in response to the alternative foraging strategies of the two predators, and suggest that prey species may not always use structured habitats as protection. This appears particularly true when a threat is perceived, but cannot immediately be located. These results provide insight to the complex and variable nature by which prey respond to various cues and predators, and offer a mechanistic guide for how behaviorally mediated and predator-predator interactions act as structuring processes in aquatic systems. PMID:20127367

  11. Characterisation of transcriptional responses to dioxins and dioxin-like contaminants in roach (Rutilus rutilus) using whole transcriptome analysis.

    PubMed

    Brinkmann, Markus; Koglin, Sven; Eisner, Bryanna; Wiseman, Steve; Hecker, Markus; Eichbaum, Kathrin; Thalmann, Beat; Buchinger, Sebastian; Reifferscheid, Georg; Hollert, Henner

    2016-01-15

    There is significant concern regarding the contamination of riverine sediments with dioxins and dioxin-like compounds (DLCs), including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and some polycyclic aromatic hydrocarbons (PAHs). The majority of studies investigating the ecotoxicology of DLCs in fish have focused on a few standard model species. However, there is significant uncertainty as to whether these model species are representative of native river fish, particularly in Europe. In this study, the transcriptional responses following exposure to equipotent concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), PCB 156 or the dioxin-like PAH, benzo[k]fluoranthene (BkF), were investigated in juvenile roach (Rutilus rutilus), a fish species that constitutes a large proportion of the fish biomass in freshwater bodies throughout Europe. To this end, RNA sequencing analysis was used to comprehensively characterise the molecular mechanisms and pathways of toxicity of these DLCs. Whole transcriptome analyses using ClueGO software revealed that DLCs have the potential to disrupt a number of important processes, including energy metabolism, oogenesis, the immune system, apoptosis and the response to oxidative stress. However, despite using equipotent concentrations, there was very little conservation of the transcriptional responses observed in fish exposed to different DLCs. TCDD provoked significant specific changes in the levels of transcripts related to immunotoxicity and carbohydrate metabolism, while PCB 156 caused virtually no specific effects. Exposure to BkF affected the most diverse suite of molecular functions and biological processes, including blood coagulation, oxidative stress responses, unspecific responses to organic or inorganic substances/stimuli, cellular redox homeostasis and specific receptor pathways. To our knowledge, this is the first study of the transcriptome-wide effects of different classes of DLCs in fish. These findings represent an important step towards describing complete toxicity pathways of DLCs, which will be important in the context of informing risk assessments of DLC toxicity in native fish species. PMID:26410716

  12. Delayed consequences of extremely low-frequency magnetic fields and the influence of adverse environmental conditions on roach Rutilus rutilus embryos.

    PubMed

    Krylov, V V; Chebotareva, Yu V; Izyumov, Yu G

    2016-04-01

    This study presents data collected over a 6 year period on the effects of extremely low-frequency magnetic fields (MFs) (1·4-1·6 µT, 500 Hz and 1·4-1·6 µT, 72·5 Hz) and MFs in combination with other environmental stressors (elevated temperature, 0·01 mg l(-1) trichlorfon, 0·01 mg l(-1) copper sulphate pentahydrate) on roach Rutilus rutilus embryos. Effects were studied during different stages of early development. Rutilus rutilus were raised in ponds for 4 months after exposure to MFs. The mass, standard length (LS ) and morphological characteristics of underyearlings which were exposed as embryos were recorded. An increase in embryo mortality and a decrease in LS and mass indices in underyearlings were noted after they had been exposed to a combination of MFs and different adverse environmental factors. In addition, exposure to MFs led to changes in the total number of vertebrae and the number of seismosensory system openings in the mandibular bones of underyearlings. MFs of different frequency caused both increases (500 Hz) and decreases (72·5 Hz) in morphological diversity. The stressors used in this study, however, did not increase the fluctuating asymmetry of bilateral morphological characteristics. The possible microevolutionary effects of exposure to MFs alone and in combination with other adverse environmental factors upon natural fish populations are discussed. PMID:26887574

  13. The effects of garlic-supplemented diets on skin mucosal immune responses, stress resistance and growth performance of the Caspian roach (Rutilus rutilus) fry.

    PubMed

    Ghehdarijani, Mahbubeh Salmanian; Hajimoradloo, Abdolmajid; Ghorbani, Rasol; Roohi, Zahra

    2016-02-01

    This study was conducted to evaluate the effects of garlic supplementation on some skin mucus immune parameters, mucus antimicrobial activity and growth performance of the Caspian roach (Rutilus rutilus caspicus) fry. Fish (1 ± 0.07 g) were divided into four groups fed diets containing 0 (control), 5, 10 and 15 g kg(-1) garlic for 8 weeks. The results showed that there was a significant increase in weight gain and specific growth rate in those fish fed garlic diets compared with the control (P < 0.05). Condition factor was not significantly affected by garlic dosage. At the end of trial, the epidermal mucus protein level, alkaline phosphatase and antimicrobial activity against 2 g-negative bacteria (Escherichia coli and Serratia marcescens) and gram-positive bacteria (Streptococcus faecium and Micrococcus luteus) were measured. Skin mucus alkaline phosphatase, protein levels and antimicrobial activity were increased following garlic administration, and the bacterial growth inhibition zones were significantly elevated in garlic-fed fish (P < 0.05). In salinity stress experiment, no differences were observed for survival rate among the experimental diets. No mortality was recorded during the feeding trial. These results indicated that dietary garlic beneficially affects the skin mucus immune parameters and growth performance of the Caspian roach fry. PMID:26700174

  14. Plasma metabolites, ions and thyroid hormones levels, and hepatic enzymes׳ activity in Caspian roach (Rutilus rutilus caspicus) exposed to waterborne manganese.

    PubMed

    Hoseini, Seyyed Morteza; Hedayati, Aliakbar; Ghelichpour, Melika

    2014-09-01

    To investigate the effect of waterborne manganese on plasma biochemical characteristics in fish, Caspian roach (Rutilus rutilus caspicus) was exposed to 0 (control), 60 (M60), 150 (M150) and 300 (M300) mg/L water manganese for 96h. Thereafter, plasma biochemical characteristics were studied. Plasma glucose level significantly increased in M60 and decreased in M150 and M300 groups, compared to the control. M300 had significantly lower hematocrit compared to the control. Albumin remained unchanged after manganese exposure, however, the manganese-exposed fish showed significant increase in plasma total protein levels. M150 and M300 showed significant increase in the plasma cholesterol and triglyceride levels compared to the control and M60. M60 and M150 had significantly higher alkaline phosphatase (ALP) activity compared to the control. The manganese-exposed groups had significantly higher alanine aminotransferase (ALT) activity compared to the control. M150 and M300 had aspartate aminotransferase (AST) activity significantly higher than those of the control and M60. M300 had significantly higher triiodothyronine (T3) levels than the other groups. All manganese-exposed fish had significantly higher thyroxin (T4) levels than the control. The plasma levels of chloride showed a significant decrease in the manganese-exposed fish, compared to the control. M150 and M300 had significantly lower sodium levels, compared to the control. M60 and M150 had significantly lower plasma calcium levels compared to the other groups. It is concluded that clinical chemistry along with thyroid hormones levels can be the useful tools to monitor manganese toxicity in fish. The possible mechanisms involving in the biochemical changes were discussed. PMID:24905699

  15. Assessing the Sensitivity of Different Life Stages for Sexual Disruption in Roach (Rutilus rutilus) Exposed to Effluents from Wastewater Treatment Works

    PubMed Central

    Liney, Katherine E.; Jobling, Susan; Shears, Jan A.; Simpson, Peter; Tyler, Charles R.

    2005-01-01

    Surveys of U.K. rivers have shown a high incidence of sexual disruption in populations of wild roach (Rutilus rutilus) living downstream from wastewater treatment works (WwTW), and the degree of intersex (gonads containing both male and female structural characteristics) has been correlated with the concentration of effluent in those rivers. In this study, we investigated feminized responses to two estrogenic WwTWs in roach exposed for periods during life stages of germ cell division (early life and the postspawning period). Roach were exposed as embryos from fertilization up to 300 days posthatch (dph; to include the period of gonadal sex differentiation) or as postspawning adult males, and including fish that had received previous estrogen exposure, for either 60 or 120 days when the annual event of germ cell proliferation occurs. Both effluents induced vitellogenin synthesis in both life stages studied, and the magnitude of the vitellogenic responses paralleled the effluent content of steroid estrogens. Feminization of the reproductive ducts occurred in male fish in a concentration-dependent manner when the exposure occurred during early life, but we found no effects on the reproductive ducts in adult males. Depuration studies (maintenance of fish in clean water after exposure to WwTW effluent) confirmed that the feminization of the reproductive duct was permanent. We found no evidence of ovotestis development in fish that had no previous estrogen exposure for any of the treatments. In wild adult roach that had previously received exposure to estrogen and were intersex, the degree of intersex increased during the study period, but this was not related to the immediate effluent exposure, suggesting a previously determined programming of ovotestis formation. PMID:16203238

  16. A new in vitro screening bioassay for the ecotoxicological evaluation of the estrogenic responses of environmental chemicals using roach (Rutilus rutilus) liver explant culture.

    PubMed

    Gerbron, Marie; Geraudie, Perrine; Rotchell, Jeanette; Minier, Christophe

    2010-10-01

    There is growing evidence that many chemicals released in the environment are able to disturb the normal endocrinology of organisms affecting the structure and function of their reproductive system. This has prompted the scientific community to develop appropriate testing methods to identify active compounds and elucidate mechanisms of action. Of particular interest are in vitro screening methods that can document the effects of these endocrine disrupting compounds on fish. In this study, an in vitro bioassay was developed in the roach (Rutilus rutilus) for evaluating the estrogenicity or antiestrogenicity potency of environmental pollutants by measuring vitellogenin (VTG) induction in cultured liver explants. The cell viability was assessed by the measurement of nonspecific esterase activity using a fluorescein diacetate hydrolysis assay. Results showed that explants could be cultured for 72 h without any significant loss of activity. Dose-dependent responses have been measured with estrogenic model compounds such as 17-β-estradiol (E2) and 17-α-ethynylestradiol (EE2) or antiestrogenic compounds such as tamoxifen. Lowest observable effective concentrations were 1 nM for E2, 1 nM for EE2, and 100 nM for tamoxifen, showing a good sensitivity of the test system. Estrogenicity of butyl 4-hydroxybenzoate, 4-nonylphenol, and bisphenol A was tested. bisphenol A (100 μM) or butylparaben induced a twofold increase in VTG production when compared with 100 nM E2, whereas this production was only 20% with 100 μM 4-nonylphenol. Overall, this study shows that the bioassay could provide valuable information on endocrine disrupting chemicals including metabolites and mixtures of compounds. PMID:20549626

  17. 17α-Ethinylestradiol (EE2) treatment of wild roach (Rutilus rutilus) during early life development disrupts expression of genes directly involved in the feedback cycle of estrogen.

    PubMed

    Nikoleris, Lina; Hultin, Cecilia L; Hallgren, Per; Hansson, Maria C

    2016-02-01

    Fish are more sensitive to introduced disturbances from synthetic endocrine disrupting compounds during early life phases compared with mature stages. 17α-Ethinylestradiol (EE2), which is the active compound in human oral contraceptives and hormone replacement therapies, is today ever present in the effluents from sewage treatment plants. EE2 targets and interacts with the endogenous biological systems of exposed vertebrates resulting in to large extents unknown short- and long-term effects. We investigated how EE2 exposure affects expression profiles of a large number of target genes during early life of roach (Rutilus rutilus). We exposed fertilized roach eggs collected from a lake in Southern Sweden to EE2 for 12weeks together with 1+-year-old roach in aquaria. We measured the gene expression of the estrogen receptor (esr)1/2a/2b, androgen receptor (ar), vitellogenin, cytochrome P450 (cyp)19a1a/1b in fertilized eggs; newly hatched larvae; 12-week-old fry; and juvenile wild roach (1+-year-old). Results shows that an EE2 concentration as low as 0.5ng/L significantly affects gene expression during early development. Gene expression responses vary both among life stages and molecular receptors. We also show that the gene profile of the estrogen feedback cycle to a large extent depends on the relationship between the three esr genes and the two cyp19a1 genes, which are all up-regulated with age. Results indicate that a disruption of the natural activity of the dominant esr gene could lead to detrimental biological effects if EE2 exposure occurs during development, even if this exposure occurred for only a short period. PMID:26689641

  18. Morphological and molecular characterization of Myxobolus mucosus sp. n. (Myxosporea: Myxobolidae) with basifilamental sporulation in two cyprinid fishes, Rutilus rutilus (L.) and Leuciscus leuciscus (L.) in Russia.

    PubMed

    Liu, X H; Voronin, V N; Dudin, A S; Zhang, J Y

    2016-03-01

    A new Myxobolus species, Myxobolus mucosus sp. n., was found in the basifilamental location of roach, Rutilus rutilus, and common dace, Leuciscus leuciscus, during the investigation of fish myxosporean fauna in Finnish Bay of Baltic Sea and Lake Ladoga in 2014. Plasmodia from the two hosts share similar morphometric and morphological features which are whitish and slightly elongated oval and measured 300-500 μm in diameter. Mature spores of M. mucosus sp. n. are ellipsoidal in frontal view and lemon shaped in sutural view, measuring 13.6 ± 0.62 (12.8-14.2) μm in length, 10.7 ± 0.51 (10.3-11.4) μm in width, 7.8 ± 0.41 (7.2-8.3) μm in thickness and 13.0 ± 0.89 (11.5-14.2) μm in length, 10.8 ± 0.77 (10.2-11.5) μm in width, 7.7 ± 0.52 (7.3-8.0) μm in thickness from roach and common dace, respectively. Polar capsules were pyriform, equal in size, converging anteriorly, with 5.9 ± 0.22 (5.7-6.3) μm in length and 3.9 ± 0.3 (3.5-4.1) μm in width and 5.6 ± 0.38 (5.1-6.2) μm in length and 3.8 ± 0.24 (3.5-4.0) μm in width from roach and common dace, respectively. Spore valves are relatively thin, symmetrical, and smooth. The most remarkable morphological character of this new Myxobolus species is the distinct mucous envelope, surrounding the full myxospore valves, up to 25 and 32 μm, respectively, in roach and common dace. The partial 18S ribosomal DNA (rDNA) sequence variation of myxospores from two hosts is very tiny (below 0.8 %) but significantly differing from all available sequences of myxosporeans in GenBank. Therefore, it can be concluded that this myxosporean from these two closely related cyprinids are conspecific by combining morphological characteristics, tissue specificity, and molecular data. Phylogenetic analysis showed that this newly described species cluster with several gill-infecting Myxobolus species from cyprinid fish inhabiting in Eastern Europe. PMID:26660693

  19. Home range, social behavior, and dominance relationships in the African unstriped ground squirrel, Xerus rutilus

    USGS Publications Warehouse

    O'Shea, Thomas J.

    1976-01-01

    A field study of home range, social behavior, and dominance relationships in the African unstriped ground squirrel, Xerus rutilus, was conducted in semi-arid bushland near Kibwezi, Kenya. Ground squirrels lived alone or in small groups in isolated burrow systems and had broadly overlapping home ranges. They were neither territorial or colonial. Home ranges were estimated by visual observation of marked animals and those of males were considerably larger (mean=7.01 hectares (ha); n=4) than those of females (mean=1.37 ha; n-6). A continuum of agonistic behavior ranging from threat to combat is described, although actual combat was rarely observed. Sexual behavior includes a stereotypical tail display by adult males. Dominance relationships, based on 542 observed encounters between marked individuals, include a consistent male dominance over females and a fairly constant linear hierarchy among all individuals with shared home ranges. Similarities in the behavior of African ground squirrels and tree squirrels (Sciurus) are discussed.

  20. Histopathological effects of atrazine on gills of Caspian kutum Rutilus frisii kutum fingerlings.

    PubMed

    Khoshnood, Zahra; Jamili, Shahla; Khodabandeh, Saber

    2015-04-01

    The use of chemical pesticides has increased environmental pollution and affects fishes as non-target organisms. To investigate the toxic effects of the widely used herbicide atrazine on Caspian kutum Rutilus frisii kutum fingerlings, fish were exposed to a sublethal concentration of half LC50 for 96 h. The main alterations visible in the gill tissue were detachment of the epithelium of the lamellae, necrosis, lamellar fusion, hyperplasia, club shaped lamellae, collapse of the lamellae, shrinkage and curling of the lamellae, and ultrastructural alterations such as necrosis of the apical microridges of the pavement cells. Results also showed that the gill ionocytes were fewer in number and larger in size in the atrazine-exposed fish. Atrazine appears to be highly toxic to Caspian kutum fingerlings even at a sublethal concentration (12.47 mg l(-1)) and acute exposure. This toxicity could affect gill respiration and ion regulation function of fingerlings by damaging tissue, pavement cells, and ionocytes. PMID:25850400

  1. Genotypic and phenotypic evaluation of Rutilus spp. from Skadar, Ohrid and Prespa Lakes supports revision of endemic as well as taxonomic status of several taxa.

    PubMed

    Milošević, D; Winkler, K A; Marić, D; Weiss, S

    2011-11-01

    One mtDNA gene (cytochrome b), one nuclear DNA fragment, five microsatellites and a suite of morphological characters were evaluated in samples of Rutilus spp. from Skadar, Ohrid and Prespa Lakes. Both genetic and phenotypic data supported two sympatric taxa in Lake Skadar, whereby Prespa and Ohrid Lakes revealed only a single taxon each. One of the taxa from Lake Skadar was similar to samples from Lake Prespa, whereas the second taxon was the most divergent in the data set. The estimated time to the most recent common ancestor of these two sympatric taxa in Lake Skadar was between 125 000 and 500 000 years. The data did not support existing taxonomic schemes for Rutilus in these lakes. This study poses the following working hypothesis: (1) Rutilus prespensis lives both in Lake Prespa and Lake Skadar and therefore is not endemic to Lake Prespa, (2) Rutilus ohridanus lives in Lake Ohrid only and therefore could be considered an endemic if its species status is retained and (3) a third recently described taxon (Rutilus albus) sympatric to R. prespensis lives in Lake Skadar. PMID:22026595

  2. Taste preferences and taste thresholds to classical taste substances in the carnivorous fish, kutum Rutilus frisii kutum (Teleostei: Cyprinidae).

    PubMed

    Goli, Sheyda; Jafari, Valiollah; Ghorbani, Rassol; Kasumyan, Alexander

    2015-03-01

    The objective of this study was to compare the taste preferences in the closely related sympatric fish species with different feeding patterns. For this purpose, palatability for four classical taste substances was evaluated for carnivorous kutum Rutilus frisii kutum and the results were compared with the taste preferences of the omnivorous roach Rutilus rutilus which had been studied earlier. In addition, the threshold concentration and the dose-response relationship of the most palatable tastants were evaluated and the ability of kutum to differentiate food with tastants in different concentrations was estimated. It was found that citric acid significantly increases the agar gel pellet consumption within the range of concentrations from 0.01M to 0.52M; the pellets with a concentration of 0.026M were the most palatable. The pellet consumption is significantly different if the concentration of citric acid in the pellets differs more than two times. The absolute threshold concentration is 0.01M, or 2.74μg of citric acid per pellet. Sucrose and NaCl have deterrent taste at the highest concentrations tested (0.29 and 1.73M, respectively). Both substances are palatable at 10 times lower concentrations and become indifferent after further gradual decrease in their concentration. CaCl2 decreases the pellets consumption at 0.9M but is an indifferent tastant at lower concentrations (0.45, 0.09 and 0.045M). The number of rejections and repeated grasps of a food pellet is fewness and is not related to the pellet's palatability, while the retention time of pellet in the oral cavity positively and highly correlates with the pellet's palatability. Kutum have opposite taste preferences for most substances tested in comparison with the roach. It indicates that the taste preferences mediated by the oral taste receptors are different in closely related sympatric fish displayed diet divergences. PMID:25497081

  3. Genome-wide comparative chromosome maps of Arvicola amphibius, Dicrostonyx torquatus, and Myodes rutilus.

    PubMed

    Romanenko, Svetlana A; Lemskaya, Natalya A; Trifonov, Vladimir A; Serdyukova, Natalya A; O'Brien, Patricia C M; Bulatova, Nina Sh; Golenishchev, Feodor N; Ferguson-Smith, Malcolm A; Yang, Fengtang; Graphodatsky, Alexander S

    2016-05-01

    The subfamily Arvicolinae consists of a great number of species with highly diversified karyotypes. In spite of the wide use of arvicolines in biological and medicine studies, the data on their karyotype structures are limited. Here, we made a set of painting probes from flow-sorted chromosomes of a male Palearctic collared lemming (Dicrostonyx torquatus, DTO). Together with the sets of painting probes made previously from the field vole (Microtus agrestis, MAG) and golden hamster (Mesocricetus auratus, MAU), we carried out a reciprocal chromosome painting between these three species. The three sets of probes were further hybridized onto the chromosomes of the Eurasian water vole (Arvicola amphibius) and northern red-backed vole (Myodes rutilus). We defined the diploid chromosome number in D. torquatus karyotype as 2n = 45 + Bs and showed that the system of sex chromosomes is X1X2Y1. The probes developed here provide a genomic tool-kit, which will help to investigate the evolutionary biology of the Arvicolinae rodents. Our results show that the syntenic association MAG1/17 is present not only in Arvicolinae but also in some species of Cricetinae; and thus, should not be considered as a cytogenetic signature for Arvicolinae. Although cytogenetic signature markers for the genera have not yet been found, our data provides insight into the likely ancestral karyotype of Arvicolinae. We conclude that the karyotypes of modern voles could have evolved from a common ancestral arvicoline karyotype (AAK) with 2n = 56 mainly by centric fusions and fissions. PMID:26611440

  4. Analysis of nodularin-R in eider (Somateria mollissima), roach (Rutilus rutilus L.), and flounder (Platichthys flesus L.) liver and muscle samples from the western Gulf of Finland, northern Baltic Sea.

    PubMed

    Sipiä, Vesa O; Sjövall, Olli; Valtonen, Terhi; Barnaby, Deborah L; Codd, Geoffrey A; Metcalf, James S; Kilpi, Mikael; Mustonen, Olli; Meriluoto, Jussi A O

    2006-11-01

    Nodularin (NODLN) is a cyanobacterial hepatotoxin that may cause toxic effects at very low exposure levels. The NODLN-producing cyanobacterium Nodularia spumigena forms massive blooms in the northern Baltic Sea, especially during the summer. We analyzed liver and muscle (edible meat) samples from common eider (Somateria mollissima), roach (Rutilus rutilus L.), and flounder (Platichthys flesus L.) for NODLN-R by liquid chromatography/mass spectrometry (LC-MS) and enzyme-linked immunosorbent assay (ELISA). Thirty eiders, 11 roach, and 15 flounders were caught from the western Gulf of Finland between September 2002 and October 2004. Eiders from April to June 2003 were found dead. The majority of samples were analyzed by LC-MS and ELISA from the same sample extracts (water:methanol:n-butanol, 75:20:5, v:v:v). Nodularin was detected in 27 eiders, nine roach, and eight flounders. Eider liver samples contained NODLN up to approximately 200 microg/kg dry weight and muscle samples at approximately 20 microg/kg dry weight, roach liver samples 20 to 900 microg NODLN/kg dry weight and muscle samples 2 to 200 microg NODLN/kg dry weight, and flounder liver samples approximately 5 to 1,100 microg NODLN/kg dry weight and muscle samples up to 100 microg NODLN/kg dry weight. The NODLN concentrations found in individual muscle samples of flounders, eiders, and roach (1-200 microg NODLN/kg dry wt) indicate that screening and risk assessment of NODLN in Baltic Sea edible fish and wildlife are required for the protection of consumer's health. PMID:17089704

  5. Histopathological alterations in the kidney of Caspian kutum, Rutilus frisii kutum, larvae and fingerlings exposed to sublethal concentration of atrazine.

    PubMed

    Khoshnood, Zahra

    2015-02-01

    The use of chemical pesticides has increased environmental pollution and affected ichthyofauna as non target organisms. In the present study, the histopathological alterations in the larvae and fingerlings of the Caspian kutum, Rutilus frisii kutum, were used as a model to investigate the toxic effects of triazine herbicide, atrazine. To investigate toxic effects of atrazine, fish were exposed to sublethal concentration of ½ LC50 for 96 h. Histologically, the most significant alterations in kidney tissues were hyperplasia, necrosis, vacuolation, swelling, hypertrophy, aggregation of hyaline droplets, and disruption of the haematopitic tissue of the head kidney. The damage was more severe in larvae than the fingerlings. Results showed that alterations in kidney tissue caused by atrazine were not specific but it could be concluded that atrazine is excessively toxic for Caspian kutum even at sublethal concentration and acute exposure. PMID:25447438

  6. Effects of parasites and antigenic challenge on metabolic rates and thermoregulation in northern red-backed voles (Myodes rutilus).

    PubMed

    Novikov, Eugene; Kondratyuk, Ekaterina; Petrovski, Dmitry; Krivopalov, Anton; Moshkin, Mikhail

    2015-12-01

    Perturbations in host energetics are considered to be an essential pathway for parasite impact on host fitness. However, direct estimations of parasite-induced variations in basal metabolic rates of vertebrate hosts have so far provided contradictory results. The energy requirements of immunity and other vital functions may be compromised in energy-demanding conditions in comparison to comfortable conditions; therefore, in our study performed on the wild red-backed vole, Myodes rutilus, we compared the values of indices that reflect metabolic and thermoregulatory responses to acute cooling in individuals that had been naturally infected by gut helminths or Ixodes persulcatus taiga ticks to individuals with no signs of infestation. To consider the possible effects of an acquired immune response on host energetics, we also injected some of the tested individuals with sheep red blood cells (SRBC). Red-backed voles infected by the nematode Heligmosomum mixtum injected with SRBC showed significantly lower cold-induced maximum oxygen consumption than the saline control. Additionally, individuals infected with H. mixtum showed significantly lower oxygen consumption during the final minute of the 15-min acute cooling period and a significantly greater decline in body temperature than individuals free from helminths. In individuals concurrently infected by H. mixtum and the cestodes Arostrilepis horrida, these indices did not differ from helminth-free individuals. The number of ticks simultaneously parasitizing the voles at the moment of capture correlated positively with their SMR. Our results suggest that even natural parasites produce deleterious effects on host aerobic capacity and thermoregulatory abilities, although the effects of different parasites might not be additive. PMID:26341798

  7. The effects of exposure duration to optimal concentration of 2-phenoxyethanol on primary and secondary stress responses in kutum (Rutilus frisii kutum).

    PubMed

    Javadi Moosavi, M; Salahi Ardekani, M M; Pirbeigi, A; Ghazi, S

    2015-08-01

    The goal of this study was to assess the anaesthetic induction and recovery time in kutum (Rutilus frisii kutum) after exposure to various concentrations (0.1, 0.3, 0.5, 0.7 and 0.9ml/l) of 2-PE as an anaesthetic, as well as the effects of optimal concentration (0.7ml/l) of 2-PE in relation to different exposure time (3, 10, 15min) on some haematological and serum biochemical indices in this species. Moreover, the effects of 0.7ml/l on blood parameters were assessed 24h after the longest exposure. Significant increase was determined in Hb, MCH and MCHC after 10-min exposure to 2-PE (p<0.05). Moreover, Hct, Hb and RBC levels increased significantly after 15min-exposure to 2-PE (p<0.05). There were no prominent changes in WBC and MCV. The plasma concentrations of glucose, cholesterol and cortisol increased significantly after 10- and 15-min exposure to 2-PE (p<0.05) compared with the control group and all other exposure times. The activity of ALT and AST were significantly increased after 10- and 15-min exposure respectively (p<0.05). In this study, it appears that anaesthetizing kutum with 2-PE at 0.7ml/l for 3min had no effect on the stress markers. PMID:25545544

  8. Effects of dietary peppermint (Mentha piperita) on growth performance, chemical body composition and hematological and immune parameters of fry Caspian white fish (Rutilus frisii kutum).

    PubMed

    Adel, Milad; Abedian Amiri, Armin; Zorriehzahra, Jalil; Nematolahi, Amin; Esteban, Maria Ángeles

    2015-08-01

    Peppermint (Mentha piperita L.) is a very popular herb. While numerous effects have been described in mammals, its effects on fish have received so far limited attention. The effects of dietary administration of peppermint on fry Caspian white fish (Rutilus frisii kutum) were studied. Fish were divided into 4 groups before being fed diets supplemented with 0% (control), 1%, 2% and 3% of peppermint extracts for 8 weeks. Dose-dependent increases of growth parameters (WG and SGR), mucus skin (protein concentration, alkaline phosphatase and antimicrobial activity) and seric (lysozyme and IgM) and blood leucocyte respiratory burst activities and different hematological parameters (number of red and white cells, seric hemoglobin and hematocrit content) were recorded in fry fish fed supplemented diets. However, the dietary peppermint supplements have different effects on the number of blood leucocytes depending on the leucocyte cell type. While no significant differences were observed in the number of blood monocytes and eosinophils, the number of neutrophils and lymphocytes was increased and decreased, respectively, on fish fed peppermint enriched diets, respect to the values found in control fish. Present results corroborate that dietary administration of peppermint promotes growth performance and increases the main hematological and immune humoral (both mucosal and systemic) parameters of fry Caspian white fish. This study may provide new applications of peppermint and, at the same time, promote rational development and utilization of peppermint resources. PMID:26067171

  9. Production of fertile unreduced sperm by hybrid males of the Rutilus alburnoides complex (Teleostei, cyprinidae). An alternative route to genome tetraploidization in unisexuals.

    PubMed Central

    Alves, M J; Coelho, M M; Próspero, M I; Collares-Pereira, M J

    1999-01-01

    The hybrid minnow Rutilus alburnoides comprises diploid and polyploid females and males. Previous studies revealed that diploid and triploid females exhibit altered oogenesis that does not involve random segregation and recombination of the genomes of the two ancestors, constituting unisexual lineages. In the present study, we investigated the reproductive mode of hybrid males from the Tejo basin, using experimental crosses and flow cytometric analysis of blood and sperm. The results suggest that diploid hybrids produced fertile unreduced sperm, transmitting their hybrid genome intact to offspring. Triploid hybrids also produced unreduced sperm, but it was not possible to obtain data concerning their fertility. Finally, tetraploid hybrids produced fertile diploid sperm, which exhibited Mendelian segregation. Tetraploid R. alburnoides may reestablish biparental reproduction, as individuals of both sexes with the appropriate constitution for normal meiosis (two haploid genomes from each parental species) are likely to occur in natural populations. Tetraploids probably have arisen from syngamy of diploid eggs and diploid sperm produced by diploid hybrid males. Diploid hybrid males may therefore play a significant role in the dynamics of the complex, starting the evolutionary process that may ultimately lead to a new sexually reproducing species. PMID:9872966

  10. The effect of the water soluble fraction of crude oil on survival, physiology and behaviour of Caspian roach, Rutilus caspicus (Yakovlev, 1870).

    PubMed

    Lari, Ebrahim; Abtahi, Behrooz; Hashtroudi, Mehri Seyed

    2016-01-01

    The water soluble fraction (WSF) of crude oil is a complex and toxic mixture of hydrocarbons that aquatic organisms directly encounter in oil spills. WSF plays an important role in the toxicity of crude oil to aquatic organisms. In the present study, the effects of WSF on juvenile Caspian roach, Rutilus caspicus, at lethal and sub-lethal level was investigated. The lethality of WSF on R. caspicus was studied by conducting 96h LC50 tests with semi-static exposure methods with 6 and 24h solution renewals. The 96h LC50 of WSF was estimated at 62.5% and 35.9% WSF concentrations for 24h and 6h renewal methods, respectively. To investigate the sub-lethal effect of WSF on R. caspicus, fish were exposed to 62.5, 31.3, and 6.3% concentrations of WSF for 24h and changes in their respiration rate and swimming activity was monitored during the exposure. At the end of the exposure period, four hematologic parameters [O2 and CO2 pressures (pO2 and pCO2), hematocrit, and hemoglobin content] of the fish were measured. The result of the behavioural experiment revealed that all three studied concentrations of WSF elevated the respiration rate and reduced the swimming activity of R. caspicus. No significant changes were detected in the hematocrit and hemoglobin content of the fish blood, but the blood pO2 of the fish exposed to 62.5% WSF decreased while the blood pCO2 increased. The results of this study suggest that the egression of the volatile components in hydrocarbon mixtures during conventional semi-static toxicity tests may lead to underestimating the toxicity of the hydrocarbons. The results of the sub-lethal experiments propose that failure of the respiratory system that leads to asphyxia may be a major mechanism that results in lethal effect of WSF in high concentrations. PMID:26377481

  11. Juvenile roach (Rutilus rutilus) increase their anaerobic metabolism in response to copper exposure in laboratory conditions.

    PubMed

    Maes, Virginie; Betoulle, Stéphane; Jaffal, Ali; Dedourge-Geffard, Odile; Delahaut, Laurence; Geffard, Alain; Palluel, Olivier; Sanchez, Wilfried; Paris-Palacios, Séverine; Vettier, Aurélie; David, Elise

    2016-07-01

    This study aims to determine the potential impairment of cell energy synthesis processes (glycolysis and respiratory chain pathways) by copper in juvenile roach at different regulation levels by using a multi-marker approach. Juvenile roach were exposed to 0, 10, 50, and 100 µg/L of copper for 7 days in laboratory conditions. The glycolysis pathway was assessed by measuring the relative expression levels of 4 genes encoding glycolysis enzymes. The respiratory chain was studied by assessing the electron transport system and cytochrome c oxidase gene expression. Muscle mitochondria ultrastructure was studied, and antioxidant responses were measured. Furthermore, the main energy reserves-carbohydrates, lipids, and proteins-were measured, and cellular energy was evaluated by measuring ATP, ADP, AMP and IMP concentrations. This study revealed a disturbance of the cell energy metabolism due to copper exposure, with a significant decrease in adenylate energy charge in roach exposed to 10 μg/L of copper after 1 day. Moreover, ATP concentrations significantly decreased in roach exposed to 10 μg/L of copper after 1 day. This significant decrease persisted in roach exposed to 50 µg/L of copper after 7 days. AMP concentrations increased in all contaminated fish after 1 day of exposure. In parallel, the relative expression of 3 genes encoding for glycolysis enzymes increased in all contaminated fish after 1 day of copper exposure. Focusing on the respiratory chain, cytochrome c oxidase gene expression also increased in all contaminated fish at the two time-points. The activity of the electron transport system was not disturbed by copper, except in roach exposed to 100 µg/L of copper after 1 day. Copper induced a metabolic stress. Juvenile roach seemed to respond to the ensuing high energy demand by increasing their anaerobic metabolism, but the energy produced by the anaerobic metabolism is unable to compensate for the stress induced by copper after 7 days. This multi-marker approach allows us to reach a greater understanding of the effects of copper on the physiological responses of juvenile roach. PMID:27033855

  12. Effect of different cooking methods on minerals, vitamins and nutritional quality indices of kutum roach (Rutilus frisii kutum).

    PubMed

    Hosseini, Hedayat; Mahmoudzadeh, Maryam; Rezaei, Masoud; Mahmoudzadeh, Leila; Khaksar, Ramin; Khosroshahi, Nader Karimian; Babakhani, Aria

    2014-04-01

    In this study, the influence of four cooking methods (baking, boiling, microwaving and frying) was evaluated on the nutritional value of kutum roach. Proximate, fatty acid composition, vitamin and mineral contents and also nutritional quality indices (NQI) of kutum roach were investigated before and after cooking treatment. All treated samples showed increase in protein, ash and lipid contents and decrease in the content of total omega-3 fatty acids (n-3) in comparison to raw fish fillets (control group). Cooking methods had no significant effect on omega-6 fatty acids (n-6) except for frying that increased it. Nonetheless, all of the cooking methods reduced vitamin B1, A and D contents. Boiling significantly decreased mineral contents including Na, K, P and Zn. Considering the overall nutritional quality indices, vitamin and mineral contents, baking is the best cooking method among other applied methods. PMID:24262530

  13. Predation resistance does not trade off with competitive ability in early-colonizing mosquitoes

    PubMed Central

    Murrell, Ebony G.; Juliano, Steven A.

    2013-01-01

    The tradeoff between colonization and competitive ability has been proposed as a mechanism for ecological succession, and this tradeoff has been demonstrated in multiple successional communities. The tradeoff between competitive ability and predation resistance is also a widely-described phenomenon; however, this tradeoff is not usually postulated as a cause of ecological succession. Early successional species that arrive before predator colonization could be either (1) Less vulnerable to predation than their successors, by virtue of being poor competitors (direct competition-predation tradeoff); (2) Equally or more vulnerable to predation, because they normally colonize ahead of predators in succession and therefore are not evolutionarily adapted to avoid predators that they rarely encounter (no competition-predation tradeoff). To test these alternative hypotheses, we established water-filled containers in an oak-hickory forest. We allowed half of the containers to be naturally colonized by early-successional Culex mosquitoes, mid-successional Aedes mosquitoes, and the mosquito predator Toxorhynchites rutilus. In the other half of the containers we prevented Aedes colonization via systematic removal of Aedes eggs, but allowed Culex and T. rutilus to colonize. The numbers of mature Culex larvae and pupae, and later the total number of Culex, were significantly greater in containers where Aedes had been removed, which suggests that Culex are competitively suppressed by Aedes. Toxorhynchites rutilus abundance and colonization rate were unaffected by the removal of Aedes, and densities of both Culex and Aedes decreased significantly with T. rutilus abundance in both treatments. In-lab bioassays showed that Culex were significantly more vulnerable to predation by T. rutilus than were Aedes. These data are consistent with the hypothesis that Culex and Aedes demonstrate a direct colonization/competition tradeoff, and are inconsistent with the hypothesis of a direct competition/predation tradeoff. PMID:23649756

  14. A new densovirus isolated from the mosquito Toxorhynchites splendens (Wiedemann) (Diptera: Culicidae).

    PubMed

    Pattanakitsakul, Sa-Nga; Boonnak, Kobporn; Auethavornanan, Kusuma; Jairungsri, Aroonroong; Duangjinda, Thaneeya; Puttatesk, Punjaporn; Thongrungkiat, Supatra; Malasit, Prida

    2007-03-01

    A new densovirus was isolated and characterized in laboratory strains of Toxorhynchites splendens. The virus was detected by polymerase chain reaction (PCR) from mosquitoes reared in our laboratory. PCR fragments from each mosquito were compared by single strand conformation polymorphism (SSCP) assay and found to be indistinguishable. Thus, it is likely the densoviruses from these mosquitoes contain homologous nucleotide sequences. The PCR fragment corresponding to a 451 bp densovirus structural gene segment from each of 5 mosquitoes had 100% identical nucleotide sequences. Phylogenetic analysis of the structural gene sequence suggests the newly isolated densovirus is more closely related to Aedes aegypti densovirus (AaeDNV) than to Aedes albopictus densovirus (AalDNV). Analysis of offspring and predated larvae suggests that vertical and horizontal transmission are responsible for chronic infections in this laboratory strain of Toxorhynchites splendens. The virion DNA is 4.2 kb in size, is closely related to, but distinct from, known densoviruses in the genera Brevidensovirus and Contravirus. Thevirus is tentatively named Toxorhynchites splendens densovirus (TsDNV). PMID:17539278

  15. Divergent and Conserved Elements Comprise the Chemoreceptive Repertoire of the Nonblood-Feeding Mosquito Toxorhynchites amboinensis

    PubMed Central

    Zhou, Xiaofan; Rinker, David C.; Pitts, Ronald Jason; Rokas, Antonis; Zwiebel, Laurence J.

    2014-01-01

    Many mosquito species serve as vectors of diseases such as malaria and yellow fever, wherein pathogen transmission is tightly associated with the reproductive requirement of taking vertebrate blood meals. Toxorhynchites is one of only three known mosquito genera that does not host-seek and initiates egg development in the absence of a blood-derived protein bolus. These remarkable differences make Toxorhynchites an attractive comparative reference for understanding mosquito chemosensation as it pertains to host-seeking. We performed deep transcriptome profiling of adult female Toxorhynchites amboinensis bodies, antennae and maxillary palps, and identified 25,084 protein-coding “genes” in the de novo assembly. Phylogenomic analysis of 4,266 single-copy “genes” from T. amboinensis, Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus robustly supported Ae. aegypti as the closest relative of T. amboinensis, with the two species diverged approximately 40 Ma. We identified a large number of T. amboinensis chemosensory “genes,” the majority of which have orthologs in other mosquitoes. Finally, cross-species expression analyses indicated that patterns of chemoreceptor transcript abundance were very similar for chemoreceptors that are conserved between T. amboinensis and Ae. aegypti, whereas T. amboinensis appeared deficient in the variety of expressed, lineage-specific chemoreceptors. Our transcriptome assembly of T. amboinensis represents the first comprehensive genomic resource for a nonblood-feeding mosquito and establishes a foundation for future comparative studies of blood-feeding and nonblood-feeding mosquitoes. We hypothesize that chemosensory genes that display discrete patterns of evolution and abundance between T. amboinensis and blood-feeding mosquitoes are likely to play critical roles in host-seeking and hence the vectorial capacity. PMID:25326137

  16. Midgut of the non-hematophagous mosquito Toxorhynchites theobaldi (Diptera, Culicidae)

    PubMed Central

    Godoy, Raquel S. M.; Fernandes, Kenner M.; Martins, Gustavo F.

    2015-01-01

    In most mosquito species, the females require a blood-feeding for complete egg development. However, in Toxorhynchites mosquitoes, the eggs develop without blood-feeding, and both females and males exclusively feed on sugary diets. The midgut is a well-understood organ in blood-feeding mosquitoes, but little is known about it in non-blood-feeding ones. In the present study, the detailed morphology of the midgut of Toxorhynchites theobaldi were investigated using histochemical and ultrastructural methods. The midgut of female and male T. theobaldi adults consists of a long, slender anterior midgut (AMG), and a short, dilated posterior midgut (PMG). The AMG is subdivided into AMG1 (short, with folds) and AMG2 (long, without folds). Nerve branches and enteroendocrine cells are present in AMG and PMG, respectively. Compared with the PMG of blood-feeding female mosquitoes, the PMG of T. theobaldi is smaller; however, in both mosquitoes, PMG seems be the main region of food digestion and absorption, and protein secretion. The epithelial folds present in the AMG of T. theobaldi have not been reported in other mosquitoes; however, the midgut muscle organization and endocrine control of the digestion process are conserved in both T. theobaldi and blood-feeding mosquitoes. PMID:26514271

  17. The physiological responses of the Caspian kutum (Rutilus frisii kutum) fry to the static magnetic fields with different intensities during acute and subacute exposures.

    PubMed

    Loghmannia, Javad; Heidari, Behrooz; Rozati, Seyed Ali; Kazemi, Soodabeh

    2015-01-01

    In recent years, the application of new technologies producing magnetic fields has widely increased in the aquatic environment. In this study, the effects of variable static magnetic fields on metabolic and immune parameters of the Caspian kutum fry were investigated. The Caspian kutum fry (n=220, body weight 1.78±0.11 g) was exposed to static magnetic fields with different intensities (2.5, 5.0, 7.5 mT) induced by electrical power supply during acute (one week) and subacute (3 weeks) periods. The results showed an increment in the quantity of ALT and AST enzymes (metabolic parameters) with increasing magnetic fields intensities in subacute and acute exposures (p<0.05). The lysozyme level, an immune parameter, showed a significant decrease, especially at intensities higher than 2.5 mT during subacute and acute exposures (p<0.05). It seems that low-intensity static magnetic fields can effect on the metabolism and immunity of the Caspian kutum fry as valuable commercial species. PMID:25450936

  18. Risky Behaviors: Effects of Toxorhynchites splendens (Diptera: Culicidae) Predator on the Behavior of Three Mosquito Species

    PubMed Central

    Zuharah, Wan Fatma; Fadzly, Nik; Yusof, Nur Aishah; Dieng, Hamady

    2015-01-01

    Viable biocontrol agents for mosquito control are quite rare, therefore improving the efficacy of existing biological agents is an important study. We need to have a better understanding of the predation-risk behavioral responses toward prey. This research examined prey choices by Toxorhynchites splendens by monitoring the behavioral responses of Aedes aegypti, Aedes albopictus, and Anopheles sinensis larvae when exposed to the predator. The results show that Tx. splendens prefers to consume Ae. aegypti larvae. The larvae exhibited different behavioral responses when Tx. splendens was present which suggest vulnerability in the presence of predators. “Thrashing” and “browsing” activities were greater in Ae. aegypti larvae. Such active and risky movements could cause vulnerability for the Ae. aegypti larvae due to increasing of water disturbance. In contrast, Ae. albopictus and An. sinensis larvae exhibited passive, low-risk behaviors, spending most of the time on the “wall” position near the edges of the container. We postulated that Ae. aegypti has less ability to perceive cues from predation and could not successfully alter its behavior to reduce risk of predation risk compared with Ae. albopictus and An. sinensis. Our results suggest that Tx. splendens is a suitable biocontrol agent in controlling dengue hemorrhagic vector, Ae. aegypti. PMID:26386041

  19. Risky behaviors: effects of Toxorhynchites splendens (Diptera: Culicidae) predator on the behavior of three mosquito species.

    PubMed

    Zuharah, Wan Fatma; Fadzly, Nik; Yusof, Nur Aishah; Dieng, Hamady

    2015-01-01

    Viable biocontrol agents for mosquito control are quite rare, therefore improving the efficacy of existing biological agents is an important study. We need to have a better understanding of the predation-risk behavioral responses toward prey. This research examined prey choices by Toxorhynchites splendens by monitoring the behavioral responses of Aedes aegypti, Aedes albopictus, and Anopheles sinensis larvae when exposed to the predator. The results show that Tx. splendens prefers to consume Ae. aegypti larvae. The larvae exhibited different behavioral responses when Tx. splendens was present which suggest vulnerability in the presence of predators. "Thrashing" and "browsing" activities were greater in Ae. aegypti larvae. Such active and risky movements could cause vulnerability for the Ae. aegypti larvae due to increasing of water disturbance. In contrast, Ae. albopictus and An. sinensis larvae exhibited passive, low-risk behaviors, spending most of the time on the "wall" position near the edges of the container. We postulated that Ae. aegypti has less ability to perceive cues from predation and could not successfully alter its behavior to reduce risk of predation risk compared with Ae. albopictus and An. sinensis. Our results suggest that Tx. splendens is a suitable biocontrol agent in controlling dengue hemorrhagic vector, Ae. aegypti. PMID:26386041

  20. Dispersal and oviposition of laboratory-reared gravid females of Toxorhynchites moctezuma in an arid urban area of Sonora, Mexico.

    PubMed

    Macías-Duarte, Alberto; Alvarado-Castro, J Andrés; Dórame-Navarro, María E; Félix-Torres, A Amalia

    2009-12-01

    Dengue is a serious public health problem worldwide. Biological control of its vector, Aedes aegypti, remains a feasible option in light of increasing urbanization and insecticide resistance. We studied the dispersal and oviposition activity of Toxorhynchites moctezuma in a dengue-endemic urban area in SSonora, Mexico, to provide information about the potential of Toxorhynchites as a control agent for Ae. aegypti in arid areas. We released 210 and 100 laboratory-reared gravid females of Tx. moctezuma in 2 city blocks during the summer and fall of 1993. We set 3 1-liter containers and 1 car tire as sentinel traps at each of 10 backyards within each city block. Spatial and temporal patterns of dispersal and oviposition activity differed between city blocks and between releases. However, a Cox regression analysis showed no significant difference in the per-day probability of Tx. moctezuma oviposition events in sentinel traps between summer and fall releases. Per-day oviposition probability was nearly 5 times greater for sentineltraps that contained larvae of Ae. aegypti, suggesting a high specificity of the predator for its prey. The proportion of sentinel traps positive for Tx. moctezuma eggs did not increase substantially after the 8th day piost-release, reaching 66% and 23% for sentinel traps with and without Ae. aegypti larvae, respectively. PMID:20099587

  1. Oral Ingestion of Transgenic RIDL Ae. aegypti Larvae Has No Negative Effect on Two Predator Toxorhynchites Species

    PubMed Central

    Nordin, Oreenaiza; Donald, Wesley; Ming, Wong Hong; Ney, Teoh Guat; Mohamed, Khairul Asuad; Halim, Nor Azlina Abdul; Winskill, Peter; Hadi, Azahari Abdul; Muhammad, Zulkamal Safi'in; Lacroix, Renaud; Scaife, Sarah; McKemey, Andrew Robert; Beech, Camilla; Shahnaz, Murad; Alphey, Luke; Nimmo, Derric David; Nazni, Wasi Ahmed; Lee, Han Lim

    2013-01-01

    Dengue is the most important mosquito-borne viral disease. No specific treatment or vaccine is currently available; traditional vector control methods can rarely achieve adequate control. Recently, the RIDL (Release of Insect carrying Dominant Lethality) approach has been developed, based on the sterile insect technique, in which genetically engineered ‘sterile’ homozygous RIDL male insects are released to mate wild females; the offspring inherit a copy of the RIDL construct and die. A RIDL strain of the dengue mosquito, Aedes aegypti, OX513A, expresses a fluorescent marker gene for identification (DsRed2) and a protein (tTAV) that causes the offspring to die. We examined whether these proteins could adversely affect predators that may feed on the insect. Aedes aegypti is a peri-domestic mosquito that typically breeds in small, rain-water-filled containers and has no specific predators. Toxorhynchites larvae feed on small aquatic organisms and are easily reared in the laboratory where they can be fed exclusively on mosquito larvae. To evaluate the effect of a predator feeding on a diet of RIDL insects, OX513A Ae. aegypti larvae were fed to two different species of Toxorhynchites (Tx. splendens and Tx. amboinensis) and effects on life table parameters of all life stages were compared to being fed on wild type larvae. No significant negative effect was observed on any life table parameter studied; this outcome and the benign nature of the expressed proteins (tTAV and DsRed2) indicate that Ae. aegypti OX513A RIDL strain is unlikely to have any adverse effects on predators in the environment. PMID:23527029

  2. Oral ingestion of transgenic RIDL Ae. aegypti larvae has no negative effect on two predator Toxorhynchites species.

    PubMed

    Nordin, Oreenaiza; Donald, Wesley; Ming, Wong Hong; Ney, Teoh Guat; Mohamed, Khairul Asuad; Halim, Nor Azlina Abdul; Winskill, Peter; Hadi, Azahari Abdul; Muhammad, Zulkamal Safi'in; Lacroix, Renaud; Scaife, Sarah; McKemey, Andrew Robert; Beech, Camilla; Shahnaz, Murad; Alphey, Luke; Nimmo, Derric David; Nazni, Wasi Ahmed; Lee, Han Lim

    2013-01-01

    Dengue is the most important mosquito-borne viral disease. No specific treatment or vaccine is currently available; traditional vector control methods can rarely achieve adequate control. Recently, the RIDL (Release of Insect carrying Dominant Lethality) approach has been developed, based on the sterile insect technique, in which genetically engineered 'sterile' homozygous RIDL male insects are released to mate wild females; the offspring inherit a copy of the RIDL construct and die. A RIDL strain of the dengue mosquito, Aedes aegypti, OX513A, expresses a fluorescent marker gene for identification (DsRed2) and a protein (tTAV) that causes the offspring to die. We examined whether these proteins could adversely affect predators that may feed on the insect. Aedes aegypti is a peri-domestic mosquito that typically breeds in small, rain-water-filled containers and has no specific predators. Toxorhynchites larvae feed on small aquatic organisms and are easily reared in the laboratory where they can be fed exclusively on mosquito larvae. To evaluate the effect of a predator feeding on a diet of RIDL insects, OX513A Ae. aegypti larvae were fed to two different species of Toxorhynchites (Tx. splendens and Tx. amboinensis) and effects on life table parameters of all life stages were compared to being fed on wild type larvae. No significant negative effect was observed on any life table parameter studied; this outcome and the benign nature of the expressed proteins (tTAV and DsRed2) indicate that Ae. aegypti OX513A RIDL strain is unlikely to have any adverse effects on predators in the environment. PMID:23527029

  3. Biosynthesis, characterization, and acute toxicity of Berberis tinctoria-fabricated silver nanoparticles against the Asian tiger mosquito, Aedes albopictus, and the mosquito predators Toxorhynchites splendens and Mesocyclops thermocyclopoides.

    PubMed

    Kumar, Palanisamy Mahesh; Murugan, Kadarkarai; Madhiyazhagan, Pari; Kovendan, Kalimuthu; Amerasan, Duraisamy; Chandramohan, Balamurugan; Dinesh, Devakumar; Suresh, Udaiyan; Nicoletti, Marcello; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Wei, Hui; Kalimuthu, Kandasamy; Hwang, Jiang-Shiou; Lo Iacono, Annalisa; Benelli, Giovanni

    2016-02-01

    Aedes albopictus is an important arbovirus vector, including dengue. Currently, there is no specific treatment for dengue. Its prevention solely depends on effective vector control measures. In this study, silver nanoparticles (AgNPs) were biosynthesized using a cheap leaf extract of Berberis tinctoria as reducing and stabilizing agent and tested against Ae. albopictus and two mosquito natural enemies. AgNPs were characterized by using UV–vis spectrophotometry, X-ray diffraction, and scanning electron microscopy. In laboratory conditions, the toxicity of AgNPs was evaluated on larvae and pupae of Ae. albopictus. Suitability Index/Predator Safety Factor was assessed on Toxorhynchites splendens and Mesocyclops thermocyclopoides. The leaf extract of B. tinctoria was toxic against larval instars (I–IV) and pupae of Ae. albopictus; LC50 was 182.72 ppm (I instar), 230.99 ppm (II), 269.65 ppm (III), 321.75 ppm (IV), and 359.71 ppm (pupa). B. tinctoria-synthesized AgNPs were highly effective, with LC50 of 4.97 ppm (I instar), 5.97 ppm (II), 7.60 ppm (III), 9.65 ppm (IV), and 14.87 ppm (pupa). Both the leaf extract and AgNPs showed reduced toxicity against the mosquito natural enemies M. thermocyclopoides and T. splendens. Overall, this study firstly shed light on effectiveness of B. tinctoria-synthesized AgNPs as an eco-friendly nanopesticide, highlighting the concrete possibility to employ this newer and safer tool in arbovirus vector control programs. PMID:26499804

  4. A multifaceted trophic cascade in a detritus-based system: density-, trait-, or processing-chain-mediated effects?

    PubMed Central

    Albeny-Simões, Daniel; Murrell, Ebony G.; Vilela, Evaldo F.; Juliano, Steven A.

    2015-01-01

    We investigated three pathways by which predators on an intermediate trophic level may produce a trophic cascade in detritus-based systems. Predators may increase lower trophic levels (bacteria) by reducing density of bacteriovores, by altering behavior of bacteriovores, and by processing living bacteriovores into carcasses, feces, and dissolved nutrients that are substrates for bacteria. We tested these pathways in laboratory experiments with mosquitoes in water-filled containers. Larval Toxorhynchites rutilus prey on larval Aedes triseriatus, which feed on bacteria. Using containers stocked with oak leaf infusion as a bacterial substrate, we compared bacterial productivity at 7 and 14 days for: prey alone; prey with a predator; and prey with predation cues but no predator. Controls contained no larvae, either with predation cues or without cues. Predation cues in the control treatment increased bacterial abundance at 7 days, but this effect waned by 14 days. Aedes triseriatus larvae reduced bacterial abundance significantly at 14 days. Predator cues and real predation both eliminated the negative effect of A. triseriatus on bacterial abundance. Predation cues reduced survivorship of A. triseriatus larvae at 14 days, however this effect was smaller than the effect of real predation. We further tested effects of residues from predation as cues or as detritus in a second experiment in which A. triseriatus were killed at similar rates by: real predators; mechanical damage without the predator and carcasses left as detritus; or mechanical damage and carcasses removed. No prey larvae were killed in controls. Bacterial productivity was greater with real predation than in all other treatments and greater when prey larvae were killed or killed and removed, than in controls. Thus we find evidence that all three pathways contribute to the trophic cascade from T. rutilus to bacteria in tree hole systems. PMID:25844268

  5. Effect of boat noise and angling on lake fish behaviour.

    PubMed

    Jacobsen, L; Baktoft, H; Jepsen, N; Aarestrup, K; Berg, S; Skov, C

    2014-06-01

    The effects of disturbances from recreational activities on the swimming speed and habitat use of roach Rutilus rutilus, perch Perca fluviatilis and pike Esox lucius were explored. Disturbances were applied for 4 h as (1) boating in short intervals with a small outboard internal combustion engine or (2) boating in short intervals combined with angling with artificial lures between engine runs. The response of the fish species was evaluated by high-resolution tracking using an automatic acoustic telemetry system and transmitters with sub-minute burst rates. Rutilus rutilus swimming speed was significantly higher during disturbances [both (1) and (2)] with an immediate reaction shortly after the engine started. Perca fluviatilis displayed increased swimming activity during the first hour of disturbance but not during the following hours. Swimming activity of E. lucius was not significantly different between disturbance periods and the same periods on days without disturbance (control). Rutilus rutilus increased their use of the central part of the lake during disturbances, whereas no habitat change was observed in P. fluviatilis and E. lucius. No difference in fish response was detected between the two types of disturbances (boating with and without angling), indicating that boating was the primary source of disturbance. This study highlights species-specific responses to recreational boating and may have implications for management of human recreational activities in lakes. PMID:24813930

  6. Nature of Predation Risk Cues in Container Systems: Mosquito Responses to Solid Residues From Predation

    PubMed Central

    KESAVARAJU, BANUGOPAN; JULIANO, STEVEN A.

    2012-01-01

    In aquatic systems, prey animals associate predation risk with cues that originate either from the predator or from injured conspecifics. Sources and benefits of these cues have received considerable attention in river, lake, and pond ecosystems but are less well understood in small container ecosystems that can hold less than a liter of water. Mosquitoes Aedes triseriatus (Say) and Aedes albopictus (Skuse) encounter predatory Corethrella appendiculata (Grabham) and Toxorhynchites rutilus (Coquillett) in small containers and show antipredatory behavioral responses. We investigated the sources of the predation cues to which these prey larvae respond. We tested whether Ae. albopictus larvae show behavioral responses to cues emanating from the predator or from damage to prey caused by the act of predation. We also tested whether Ae. triseriatus respond to cues present in fluid or solid residues from predator activity. Ae. albopictus showed behavioral modifications only in response to waterborne cues from a feeding predator and not to cues from a starving predator, indicating that Ae. albopictus respond to cues created by the act of predation, which could include substances derived from damaged prey or substances in predator feces. Ae. triseriatus showed behavioral responses to solid residues from predation but not to fluid without those solids, indicating that the cues to which they respond originate in predator feces or uneaten prey body parts. Our results suggest that cues in this system may be primarily chemicals that are detected upon contact with solid residues that are products of the feeding processes of these predators. PMID:22740721

  7. Successional mosquito dynamics in surrogate treehole and ground-container habitats in the northeastern United States: where does Aedes albopictus fit in?

    PubMed

    Johnson, B J; Sukhdeo, M V K

    2013-06-01

    This study assessed the risk of larval displacement of the eastern treehole mosquito, Aedes triseriatus, and the northern house mosquito, Culex pipiens, by Aedes albopictus, the Asian tiger mosquito, during the establishment and successional stages of novel larval mosquito treehole and ground-container habitats in the state of New Jersey, U.S.A. Culex pipiens and Culex restuans were the first mosquito species to colonize ground-container habitats and were the dominant larval species throughout the study period, whereas Ae. albopictus was late to colonize ground habitats and accounted for less than 15% of weekly larval collections once established. Ae. albopictus had a much stronger community presence within treehole ovitraps; however, Ae. albopictus never reached the average larval densities of the expected primary colonizer, Ae. triseriatus. Throughout the study period, the weekly abundances of Ae. triseriatus and Ae. albopictus were positively correlated and there were no significant differences between the abundances of each species. The larval dominance of Ae. triseriatus appears to be enhanced by the presence of Toxorhynchites rutilus septentrionalis, a large predatory mosquito species. When Tx. rut. septentrionalis was present, mature larvae (3(rd) -4(th) instar) of Ae. albopictus were also present in only 16.7% of collections, whereas mature larvae of Ae. triseriatus were collected concurrently with Tx. rut. septentrionalis in 53.8% of collections. These data suggest that Ae. triseriatus is at a greater risk of displacement by Ae. albopictus than are Cx. pipiens and Cx. restuans. PMID:23701622

  8. [Evaluation of cytophysiological state of testis in forest voles living in the radioactively contaminated areas].

    PubMed

    Mamina, V P

    2005-01-01

    We made a cytophysiological analys of testis in Clethrionomus rutilus and Apodemus sylvaticus inhabiting a contaminated area of the East Ural Radioactive Trace (EURT). The study showed that in the norm these species differed in the total number of cells of spermatogenous epithelium, due to interspecific difference. In the sampling plot a concentration of 90Sr in Clethrionomus rutilus was 2 times higher than that in Apodemus sylvaticus. Maximum destructive changes in endocrine and exocrine (seminiferous tubules) section of testis and increased proliferation activity of spermatogenous epithelium were observed in Clethrionomus rutilus.Increased proliferation activity was found as a compensatory-protective reaction which promote the maintenance of the germ cell number. Such changes were not observed in Apodemus sylvaticus. PMID:15810529

  9. Response of animal and vegetative cells to the effect of a typical magnetic storm

    NASA Astrophysics Data System (ADS)

    Talikina, M. G.; Izyumov, Yu. G.; Krylov, V. V.

    2013-12-01

    Experimentally reproduced fluctuations of a low-frequency magnetic field in a nanotesla range (magnetic storm) affect the mitosis of animals and vegetative cells. Action of this factor during twenty four hours leads to a significant increase in the proliferative activity of embryo cells in roach ( Rutilus rutilus L.) and meristem cells of onion rootlets ( Allium cepa). The clastogenic effect statistically confirmed only in the Allium test seems to reflect the species specificity of the response and higher sensitivity of the cell association of the onion meristem to magnetic storm.

  10. Urban Mosquito Fauna in Mérida City, México: Immatures Collected from Containers and Storm-water Drains/Catch Basins

    PubMed Central

    Baak-Baak, Carlos M.; Arana-Guardia, Roger; Cigarroa-Toledo, Nohemi; Puc-Tinal, María; Coba-Tún, Carlos; Rivero-Osorno, Víctor; Lavalle-Kantun, Damián; Loroño-Pino, María Alba; Machain-Williams, Carlos; Reyes-Solis, Guadalupe C.; Beaty, Barry J.; Eisen, Lars; García-Rejón, Julián E.

    2014-01-01

    We examined the species composition and temporal occurrence of immature mosquitoes in containers and storm-water drains/catch basins from November 2011 to June 2013 in Mérida City, México. A wide range of urban settings were examined, including residential premises, vacant lots, parking lots, and streets or sidewalks with storm-water drains/catch basins. In total, 111,776 specimens of 15 species were recorded. The most commonly collected species were Aedes (Stegomyia) aegypti (L.) (n = 60,961) and Culex quinquefasciatus Say (45,702), which together accounted for 95.4% of the immatures collected. These species were commonly encountered during both rainy and dry seasons, whereas most other mosquito species were collected primarily during the rainy season. Other species collected were Aedes (Howardina) cozumelensis Diaz Najera, Aedes (Ochlerotatus) taeniorhynchus (Wiedemann), Aedes (Ochlerotatus) trivittatus (Coquillett), Culex coronator Dyar and Knab, Culex interrogator Dyar and Knab, Culex lactator Dyar and Knab, Culex nigripalpus Theobald, Culex salinarius Coquillett, Culex tarsalis Coquillett, Culex thriambus Dyar, Haemagogus equinus Theobald, Limatus durhamii Theobald, and Toxorhynchites rutilus (Coquillett). The greatest number of species was recorded from vacant lots (n = 11), followed by storm-water drains/catch basins (nine) and residential premises (six). Our study demonstrated that the heterogeneous urban environment in Mérida City supports a wide range of mosquito species, many of which are nuisance biters of humans and/or capable of serving as vectors of pathogens affecting humans or domestic animals. We also briefly reviewed the medical importance of the encountered mosquito species. PMID:25429168

  11. Mosquito Larvae in Tires from Mississippi, United States: The Efficacy of Abiotic and Biotic Parameters in Predicting Spatial and Temporal Patterns of Mosquito Populations and Communities

    PubMed Central

    Yee, Donald A.; Abuzeineh, Alisa A.; Ezeakacha, Nnaemeka F.; Schelble, Stephanie S.; Glasgow, William C.; Flanagan, Stephen D.; Skiff, Jeffrey J.; Reeves, Ashton; Kuehn, Kevin

    2015-01-01

    Container systems, including discarded vehicle tires, which support populations of mosquitoes, have been of interest for understanding the variables that produce biting adults that serve as both nuisances and as public health threats. We sampled tires in six sites at three times in 2012 across the state of Mississippi to understand the biotic and abiotic variables responsible for explaining patterns of larvae of common species, species richness, and total abundance of mosquitoes. From 498 tires sampled, we collected >58,000 immatures representing 16 species, with the most common species including Aedes albopictus (Skuse), Culex quinquefasciatus (L.), Orthopodomyia signifera (Coquillett), Aedes triseriatus (Say), Toxorhynchites rutilus septentrionalis (Coquillett), and Culex territans (Walker) accounting for ∼97% of all larvae. We also documented 32 new county records for resident species and recent arrivals in the state, including Aedes japonicus japonicus (Theobald) and Culex coronator (Dyar & Knab). Cluster analysis, which was used to associate sites and time periods based on similar mosquito composition, did reveal patterns across the state; however, there also were more general patterns between species and genera and environmental factors. Broadly, Aedes was often associated with factors related to detritus, whereas Culex was frequently associated with habitat variables (e.g., tire size and water volume) and microorganisms. Some Culex did lack factors connecting variation in early and late instars, suggesting differences between environmental determinants of oviposition and survival. General patterns between the tire environment and mosquito larvae do appear to exist, especially at the generic level, and point to inherent differences between genera that may aid in predicting vector locations and populations. PMID:26334813

  12. Urban Mosquito Fauna in Mérida City, México: Immatures Collected from Containers and Storm-water Drains/Catch Basins.

    PubMed

    Baak-Baak, Carlos M; Arana-Guardia, Roger; Cigarroa-Toledo, Nohemi; Puc-Tinal, María; Coba-Tún, Carlos; Rivero-Osorno, Víctor; Lavalle-Kantun, Damián; Loroño-Pino, María Alba; Machain-Williams, Carlos; Reyes-Solis, Guadalupe C; Beaty, Barry J; Eisen, Lars; García-Rejón, Julián E

    2014-06-01

    We examined the species composition and temporal occurrence of immature mosquitoes in containers and storm-water drains/catch basins from November 2011 to June 2013 in Mérida City, México. A wide range of urban settings were examined, including residential premises, vacant lots, parking lots, and streets or sidewalks with storm-water drains/catch basins. In total, 111,776 specimens of 15 species were recorded. The most commonly collected species were Aedes (Stegomyia) aegypti (L.) (n = 60,961) and Culex quinquefasciatus Say (45,702), which together accounted for 95.4% of the immatures collected. These species were commonly encountered during both rainy and dry seasons, whereas most other mosquito species were collected primarily during the rainy season. Other species collected were Aedes (Howardina) cozumelensis Diaz Najera, Aedes (Ochlerotatus) taeniorhynchus (Wiedemann), Aedes (Ochlerotatus) trivittatus (Coquillett), Culex coronator Dyar and Knab, Culex interrogator Dyar and Knab, Culex lactator Dyar and Knab, Culex nigripalpus Theobald, Culex salinarius Coquillett, Culex tarsalis Coquillett, Culex thriambus Dyar, Haemagogus equinus Theobald, Limatus durhamii Theobald, and Toxorhynchites rutilus (Coquillett). The greatest number of species was recorded from vacant lots (n = 11), followed by storm-water drains/catch basins (nine) and residential premises (six). Our study demonstrated that the heterogeneous urban environment in Mérida City supports a wide range of mosquito species, many of which are nuisance biters of humans and/or capable of serving as vectors of pathogens affecting humans or domestic animals. We also briefly reviewed the medical importance of the encountered mosquito species. PMID:25429168

  13. Mosquito Larvae in Tires from Mississippi, United States: The Efficacy of Abiotic and Biotic Parameters in Predicting Spatial and Temporal Patterns of Mosquito Populations and Communities.

    PubMed

    Yee, Donald A; Abuzeineh, Alisa A; Ezeakacha, Nnaemeka F; Schelble, Stephanie S; Glasgow, William C; Flanagan, Stephen D; Skiff, Jeffrey J; Reeves, Ashton; Kuehn, Kevin

    2015-05-01

    Container systems, including discarded vehicle tires, which support populations of mosquitoes, have been of interest for understanding the variables that produce biting adults that serve as both nuisances and as public health threats. We sampled tires in six sites at three times in 2012 across the state of Mississippi to understand the biotic and abiotic variables responsible for explaining patterns of larvae of common species, species richness, and total abundance of mosquitoes. From 498 tires sampled, we collected >58,000 immatures representing 16 species, with the most common species including Aedes albopictus (Skuse), Culex quinquefasciatus (L.), Orthopodomyia signifera (Coquillett), Aedes triseriatus (Say), Toxorhynchites rutilus septentrionalis (Coquillett), and Culex territans (Walker) accounting for ∼97% of all larvae. We also documented 32 new county records for resident species and recent arrivals in the state, including Aedes japonicus japonicus (Theobald) and Culex coronator (Dyar & Knab). Cluster analysis, which was used to associate sites and time periods based on similar mosquito composition, did reveal patterns across the state; however, there also were more general patterns between species and genera and environmental factors. Broadly, Aedes was often associated with factors related to detritus, whereas Culex was frequently associated with habitat variables (e.g., tire size and water volume) and microorganisms. Some Culex did lack factors connecting variation in early and late instars, suggesting differences between environmental determinants of oviposition and survival. General patterns between the tire environment and mosquito larvae do appear to exist, especially at the generic level, and point to inherent differences between genera that may aid in predicting vector locations and populations. PMID:26334813

  14. The valid generic name for red-backed voles (Muroidea: Cricetidae: Arvicolinae): restatement of the case for Myodes Pallas, 1811

    USGS Publications Warehouse

    Carleton, Michael D.; Gardner, Alfred L.; Pavlinov, Igor Ya.; Musser, Guy G.

    2014-01-01

    In view of contradictions in the recent literature, the valid genus-group name to be applied to northern red-backed voles—Myodes Pallas, 1811, or Clethrionomys Tilesius, 1850—is reviewed. To develop the thesis that Myodes (type species, Mus rutilus Pallas, 1779) is the correct name, our discussion explores the 19th-century taxonomic works that bear on the relevant taxa, the transition in zoological codes apropos the identification of type species, and past nomenclatural habits in cases where no type species was originally indicated. We conclude that Myodes is the senior name to use for the genus-group taxon that includes the Holarctic species rutilus and frame this conclusion within a synonymy of the genus.

  15. Trophic flexibility and opportunism in pike Esox lucius.

    PubMed

    Pedreschi, D; Mariani, S; Coughlan, J; Voigt, C C; O'Grady, M; Caffrey, J; Kelly-Quinn, M

    2015-10-01

    The first comprehensive investigation of pike Esox lucius trophic ecology in a region (Ireland) where they have long been thought to be a non-native species is presented. Diet was investigated across habitat types (lake, river and canal) through the combined methods of stable-isotope and stomach content analyses. Variations in niche size, specialization and the timing of the ontogenetic dietary switch were examined, revealing pronounced opportunism and feeding plasticity in E. lucius, along with a high occurrence of invertivory (up to 60 cm fork length, LF ) and a concomitant delayed switch to piscivory. Furthermore, E. lucius were found to primarily prey upon the highly available non-native roach Rutilus rutilus, which may alleviate predation pressure on brown trout Salmo trutta, highlighting the complexity of dynamic systems and the essential role of research in informing effective management. PMID:26351044

  16. [Infection with opistorchis larvae in the fish family cyprinidae in the Ob-Irtysh River basin in the Tyumen region].

    PubMed

    2012-01-01

    Fishes, such as ide (Leuciscus idus), dace (Leuciscus leuciscus), carpbream (Abramis brama), roach (Rutilus rutilus), and muvarica (Alburnus alburnus), with different frequency and rate of invasion and abundance index were infested with larvae of O. felineus, M. bilis, and P. truncatum. There were the highest rates of fish infection with P. truncatum larvae in the subtaiga zone (the south of the region) and with O. felineus metacercariae in the northern subtaiga and taiga zones. In research, experimental, and clinical studies, the nosological entity opisthorchiasis is a parasitic cenosis consisting of 2-3 co-members requiring their specific identification, which allows therapeutic measures to be more effectively implemented among the population of a hyperendemic focus. PMID:23437717

  17. Extensive erythrocyte deformation in fish gills observed by in vivo microscopy: apparent adaptations for enhancing oxygen uptake

    PubMed

    Nilsson; LÖFman; Block

    1995-01-01

    The secondary lamellae of the gills are the primary sites of oxygen uptake in fish. We have used epi-illumination microscopy in vivo to observe the microcirculation directly in secondary lamellae of rainbow trout (Oncorhynchus mykiss) and roach (Rutilus rutilus). Our observations point at previously unrecognised factors in fish respiratory physiology. Erythrocytes passing through secondary lamellae became greatly deformed. We propose that this deformation plays a role in oxygen uptake by diminishing the diffusion boundary layer (adhesion layer) of fluid around the erythrocyte and possibly also by mixing intracellular haemoglobin molecules. Moreover, the erythrocytes were apparently slowed down and forced to travel over an extended path to pass through the lamella, making it tempting to speculate that plasma passes more readily than erythrocytes through the lamella, resulting in a local elevation of the haematocrit. PMID:9318984

  18. Molecular and ecological signs of mitochondrial adaptation: consequences for introgression?

    PubMed

    Boratyński, Z; Melo-Ferreira, J; Alves, P C; Berto, S; Koskela, E; Pentikäinen, O T; Tarroso, P; Ylilauri, M; Mappes, T

    2014-10-01

    The evolution of the mitochondrial genome and its potential adaptive impact still generates vital debates. Even if mitochondria have a crucial functional role, as they are the main cellular energy suppliers, mitochondrial DNA (mtDNA) introgression is common in nature, introducing variation in populations upon which selection may act. Here we evaluated whether the evolution of mtDNA in a rodent species affected by mtDNA introgression is explained by neutral expectations alone. Variation in one mitochondrial and six nuclear markers in Myodes glareolus voles was examined, including populations that show mtDNA introgression from its close relative, Myodes rutilus. In addition, we modelled protein structures of the mtDNA marker (cytochrome b) and estimated the environmental envelopes of mitotypes. We found that massive mtDNA introgression occurred without any trace of introgression in the analysed nuclear genes. The results show that the native glareolus mtDNA evolved under past positive selection, suggesting that mtDNA in this system has selective relevance. The environmental models indicate that the rutilus mitotype inhabits colder and drier habitats than the glareolus one that can result from local adaptation or from the geographic context of introgression. Finally, homology models of the cytochrome b protein revealed a substitution in rutilus mtDNA in the vicinity of the catalytic fraction, suggesting that differences between mitotypes may result in functional changes. These results suggest that the evolution of mtDNA in Myodes may have functional, ecological and adaptive significance. This work opens perspective onto future experimental tests of the role of natural selection in mtDNA introgression in this system. PMID:24690754

  19. Molecular and ecological signs of mitochondrial adaptation: consequences for introgression?

    PubMed Central

    Boratyński, Z; Melo-Ferreira, J; Alves, P C; Berto, S; Koskela, E; Pentikäinen, O T; Tarroso, P; Ylilauri, M; Mappes, T

    2014-01-01

    The evolution of the mitochondrial genome and its potential adaptive impact still generates vital debates. Even if mitochondria have a crucial functional role, as they are the main cellular energy suppliers, mitochondrial DNA (mtDNA) introgression is common in nature, introducing variation in populations upon which selection may act. Here we evaluated whether the evolution of mtDNA in a rodent species affected by mtDNA introgression is explained by neutral expectations alone. Variation in one mitochondrial and six nuclear markers in Myodes glareolus voles was examined, including populations that show mtDNA introgression from its close relative, Myodes rutilus. In addition, we modelled protein structures of the mtDNA marker (cytochrome b) and estimated the environmental envelopes of mitotypes. We found that massive mtDNA introgression occurred without any trace of introgression in the analysed nuclear genes. The results show that the native glareolus mtDNA evolved under past positive selection, suggesting that mtDNA in this system has selective relevance. The environmental models indicate that the rutilus mitotype inhabits colder and drier habitats than the glareolus one that can result from local adaptation or from the geographic context of introgression. Finally, homology models of the cytochrome b protein revealed a substitution in rutilus mtDNA in the vicinity of the catalytic fraction, suggesting that differences between mitotypes may result in functional changes. These results suggest that the evolution of mtDNA in Myodes may have functional, ecological and adaptive significance. This work opens perspective onto future experimental tests of the role of natural selection in mtDNA introgression in this system. PMID:24690754

  20. New method for visualization of C-heterochromatin in synaptonemal complex spreads.

    PubMed

    Lisachov, Artem P

    2013-01-01

    DAPI staining of the metaphase chromosomes pretreated with barium hydroxide generates a C-like banding pattern. In this work a protocol for visualizing similar pattern at the synaptonemal complex (SC) spreads after immunostaining is suggested. This method was used to visualize centromeric and sex heterochromatin at the SC spreads of guppy fish (Poecilia reticulata Peters, 1859). The efficiency of this method was further confirmed at SC spreads of the northern red-backed vole (Myodes rutilus (Pallas, 1779)), the guinea pig (Cavia porcellus (Linnaeus, 1758)), and the pigmy shrew (Sorex minutus Linnaeus, 1766). PMID:24260695

  1. Introgression of mitochondrial DNA among Myodes voles: consequences for energetics?

    PubMed Central

    2011-01-01

    Background Introgression of mitochondrial DNA (mtDNA) is among the most frequently described cases of reticulate evolution. The tendency of mtDNA to cross interspecific barriers is somewhat counter-intuitive considering the key function of enzymes that it encodes in the oxidative-phosphorylation process, which could give rise to hybrid dysfunction. How mtDNA reticulation affects the evolution of metabolic functions is, however, uncertain. Here we investigated how morpho-physiological traits vary in natural populations of a common rodent (the bank vole, Myodes glareolus) and whether this variation could be associated with mtDNA introgression. First, we confirmed that M. glareolus harbour mtDNA introgressed from M. rutilus by analyzing mtDNA (cytochrome b, 954 bp) and nuclear DNA (four markers; 2333 bp in total) sequence variation and reconstructing loci phylogenies among six natural populations in Finland. We then studied geographic variation in body size and basal metabolic rate (BMR) among the populations of M. glareolus and tested its relationship with mtDNA type. Results Myodes glareolus and its arctic neighbour, M. rutilus, are reciprocally monophyletic at the analyzed nuclear DNA loci. In contrast, the two northernmost populations of M. glareolus have a fixed mitotype that is shared with M. rutilus, likely due to introgressive hybridization. The analyses of phenotypic traits revealed that the body mass and whole-body, but not mass corrected, BMR are significantly reduced in M. glareolus females from northern Finland that also have the introgressed mitotype. Restricting the analysis to the single population where the mitotypes coexist, the association of mtDNA type with whole-body BMR remained but those with mass corrected BMR and body mass did not. Mitochondrial sequence variation in the introgressed haplotypes is compatible with demographic growth of the populations, but may also be a result of positive selection. Conclusion Our results show that the phenotypic traits vary markedly along the north-south axis of populations of M. glareolus. This variation may be related to adaptation to local environments and coincides with the gradient of genome reticulation between M. glareolus and M. rutilus, which was assessed by mtDNA introgression. Introgression of mtDNA may have affected morpho-physiological traits but do not show strong effects on either body mass or basal metabolic rate alone. We discuss the causes and biological meaning of our results and the means to clarify these questions in future research. PMID:22151479

  2. Migration confers survival benefits against avian predators for partially migratory freshwater fish.

    PubMed

    Skov, Christian; Chapman, Ben B; Baktoft, Henrik; Brodersen, Jakob; Brönmark, Christer; Hansson, Lars-Anders; Hulthén, Kaj; Nilsson, P Anders

    2013-04-23

    The importance of predation risk in shaping patterns of animal migration is not well studied, mostly owing to difficulties in accurately quantifying predation risk for migratory versus resident individuals. Here, we present data from an extensive field study, which shows that migration in a freshwater fish (roach, Rutilus rutilus) that commonly migrates from lakes to streams during winter confers a significant survival benefit with respect to bird (cormorant, Phalacrocorax carbo spp.) predation. We tagged over 2000 individual fish in two Scandinavian lakes over 4 years and monitored migratory behaviour using passive telemetry. Next, we calculated the predation vulnerability of fish with differing migration strategies, by recovering data from passive integrated transponder tags of fish eaten by cormorants at communal roosts close to the lakes. We show that fish can reduce their predation risk from cormorants by migrating into streams, and that probability of being preyed upon by cormorants is positively related to the time individuals spend in the lake during winter. Our data add to the growing body of evidence that highlights the importance of predation for migratory dynamics, and, to our knowledge, is one of the first studies to directly quantify a predator avoidance benefit to migrants in the field. PMID:23445943

  3. Factors Affecting Antioxidant Response in Fish from a Long-term Mercury-Contaminated Reservoir.

    PubMed

    Sevcikova, M; Modra, H; Blahova, J; Dobsikova, R; Kalina, J; Zitka, O; Kizek, R; Svobodova, Z

    2015-11-01

    The objective of this work was to evaluate antioxidant defence and oxidative damage in organs (liver, gills, kidney, and brain) of five fish species (Aspius aspius, Esox lucius, Sander lucioperca, Abramis brama, Rutilus rutilus) from the long-term mercury-contaminated Skalka Reservoir in the Czech Republic. Special emphasis was placed on a comprehensive assessment of the factors that may affect the antioxidant response to mercury in fish. Antioxidant enzymes (glutathione reductase, glutathione peroxidase, and glutathione-S-transferase) did not significantly respond to mercury contamination. Levels of the analysed enzymes and oxidative damage to lipids were predominantly determined by a separate organ factor or species factor, or by the combination of both (p < 0.001). Levels of total glutathione and the reduced/oxidized glutathione ratio were influenced by mercury contamination in combination with their specific organ distribution (p < 0.001). Our results suggest that species and type of organ alone or in combination are more important factors than chronic exposure to mercury contamination with respect to effects on antioxidant defence in fish under field conditions. Our findings suggest that the main antioxidant defensive mechanism in fish from the studied long-term mercury contaminated site was the inter-tissue distribution of glutathione. PMID:26276034

  4. Former uranium mine-induced effects in caged roach: a multiparametric approach for the evaluation of in situ metal toxicity.

    PubMed

    Gagnaire, Béatrice; Bado-Nilles, Anne; Betoulle, Stéphane; Amara, Rachid; Camilleri, Virginie; Cavalié, Isabelle; Chadili, Edith; Delahaut, Laurence; Kerambrun, Elodie; Orjollet, Daniel; Palluel, Olivier; Sanchez, Wilfried

    2015-01-01

    To characterize environmental risks linked to former uranium mines in the Limousin region of France, a study was conducted on fish health effects from uranium releases. Two private ponds were compared in this study, one with uranium contamination and one background site, upstream of the mining zone. Roach, Rutilus rutilus, were caged for 28 days in both ponds. Physico-chemical parameters of water and sediments and bioaccumulation of metals in several organs were determined. After 14 and 28 days of caging, immune, oxidative stress, biotransformation, neurotoxicity and physiological parameters were measured. Iron and aluminium were quantified in the water of both sites; however, barium and manganese were only present in the water of the uranium contaminated site. Uranium was present in both sites but at very different concentrations. The sediments from the uranium contaminated site contained high levels of radioactive elements coming from the disintegration chain of uranium. Results of biological parameters indicated stimulation of immune parameters and of oxidative stress and a decrease of AChE in fish caged in the uranium contaminated pond compared to the uranium-free pond. Overall, the results determined roach health status in the context of pollution from poly-metallic mining. The data strengthen our knowledge of the environmental risk assessment associated with radioactive substances in the environment. PMID:25348601

  5. Distribution and ecology of Dreissena polymorpha (pallas) and Dreissena bugensis (andrusov) in the upper Volga basin

    USGS Publications Warehouse

    Shcherbina, G. Kh; Buckler, D.R.

    2006-01-01

    This paper presents data on contemporary distribution patterns of two species of Dreissenidae, the zebra mussel (Dreissena polymorpha) and the Quagga mussel (Dreissena bugensis), and their role in ecosystem processes in the Ivan'kovo, Uglich, Rybinsk, and Gorky Reservoirs of the Upper Volga River basin. The role of zebra mussel was also studied in experimental mesocosms of 15 m3. Maximum abundance and species diversity of macroinvertebrates, especially of leeches, polychaetes, crustaceans, and heterotopic insects, were attained in the portions of reservoirs where Dreissenidae were present and in experimental mesocosms where zebra mussel biomass was the highest. In the mesocosm studies, the presence of zebra mussel druses (colonies) provided shelter for macroinvertebrates, reducing their vulnerability to predation by perch (Perca fluviatills) larvae and yearlings, thereby increasing macroinvertebrate species diversity. It was shown that in addition to its role in aquatic biocenosis (ecological community) formation and water purification, Dreissenidae are important food objects for benthophagous fishes, especially roach (Rutilus rutilus). Examination of intestines of benthophagous fishes showed that the length of Dreissenidae ranged from 5 to 20 mm in roach; from 4 to 14 mm in silver bream (Blicca bjoerkna), and from 2 to 10 mm in bream (Abramis brama). The largest mussels consumed were Quagga mussels up to 30 mm, noted in the predatory cyprinid, ide (Leuciscus idus). Copyright ?? 2006 by ASTM International.

  6. Dietary effects on fatty acid composition in muscle tissue of juvenile European eel, Anguilla anguilla (L.)

    NASA Astrophysics Data System (ADS)

    Prigge, Enno; Malzahn, Arne M.; Zumholz, Karsten; Hanel, Reinhold

    2012-03-01

    The role of intracontinental migration patterns of European eel ( Anguilla anguilla) receives more and more recognition in both ecological studies of the European eel and possible management measures, but small-scale patterns proved to be challenging to study. We experimentally investigated the suitability of fatty acid trophic markers to elucidate the utilization of feeding habitats. Eight groups of juvenile European eels were fed on eight different diets in a freshwater recirculation system at 20°C for 56 days. Three groups were fed on freshwater diets ( Rutilus rutilus, Chironomidae larvae, and Gammarus pulex) and four groups were reared on diets of a marine origin ( Clupea harengus, Crangon crangon, Mysis spec., and Euphausia superba) and one on commercial pellets used in eel aquaculture. Fatty acid composition (FAC) of diets differed significantly with habitat. FAC of eel muscle tissue seemed to be rather insensitive to fatty acids supplied with diet, but the general pattern of lower n3:n6 and EPA:ARA ratios in freshwater prey organisms could be traced in the respective eels. Multivariate statistics of the fatty acid composition of the eels resulted in two distinct groups representing freshwater and marine treatments. Results further indicate the capability of selectively restraining certain fatty acids in eel, as e.g. the n3:n6 ratio in all treatments was <4, regardless of dietary n3:n6. In future studies on wild eel, these measures can be used to elucidate the utilization of feeding habitats of individual European eel.

  7. Interactions between predation and resources shape zooplankton population dynamics.

    PubMed

    Nicolle, Alice; Hansson, Lars-Anders; Brodersen, Jakob; Nilsson, P Anders; Brönmark, Christer

    2011-01-01

    Identifying the relative importance of predation and resources in population dynamics has a long tradition in ecology, while interactions between them have been studied less intensively. In order to disentangle the effects of predation by juvenile fish, algal resource availability and their interactive effects on zooplankton population dynamics, we conducted an enclosure experiment where zooplankton were exposed to a gradient of predation of roach (Rutilus rutilus) at different algal concentrations. We show that zooplankton populations collapse under high predation pressure irrespective of resource availability, confirming that juvenile fish are able to severely reduce zooplankton prey when occurring in high densities. At lower predation pressure, however, the effect of predation depended on algal resource availability since high algal resource supply buffered against predation. Hence, we suggest that interactions between mass-hatching of fish, and the strong fluctuations in algal resources in spring have the potential to regulate zooplankton population dynamics. In a broader perspective, increasing spring temperatures due to global warming will most likely affect the timing of these processes and have consequences for the spring and summer zooplankton dynamics. PMID:21304980

  8. Feeding guilds and food resource partitioning in a lake fish assemblage: an ontogenetic approach.

    PubMed

    Specziár, A; Rezsu, E T

    2009-07-01

    Ontogenetic diet patterns and trophic guild structure of a 15 species temperate lake fish assemblage were analysed over wide size intervals (up to seven orders of magnitude in body mass), representing practically the whole life span in most species. A two-step objective clustering technique supplemented with other multivariate statistical tools proved that size-related diet changes clearly played an important role in structuring trophic organization of fishes inhabiting Lake Balaton. As many as 13 out of the 15 fish species showed marked size-related dietary changes with two to four ontogenetic feeding stages. At the assemblage level, 11 trophic guilds were separated. Guild membership was size-dependent in 11 fish species that participated in two to four trophic guilds during their life span. The most complex trophic ontogeny was observed in roach Rutilus rutilus and asp Aspius aspius with four guild memberships. This study showed that trophic status of fishes may be very size-sensitive and thus a universal classification of fish species to general trophic guilds, such as 'planktivore', 'benthivore', 'piscivore' or 'herbivore', should be applied very carefully even in environmental monitoring and fisheries management applications, unless it is supported by relevant results of life span diet analyses. PMID:20738494

  9. [Care of young, aggressiveness, and secretion of testosterone in male rodents: a correlation analysis ].

    PubMed

    Gromov, V S; Voznesenskaia, V V

    2013-01-01

    To test the current hypotheses on the relationship between the mating system, reproductive strategy, aggression, and secretion of testosterone, a comparative study of interactions in pair encounters, the level of parental care, and the gonadal testosterone level in males was performed in six rodent species (Clethrionomys rutilus, Meriones meridianus, Microtus arvalis, Lagurus lagurus, Lasiopodomys Mandarinus, and Meriones unguiculatus) with different types of spatial-and-ethological population structures (SEPSs). It is shown that this. dependence is absent in species with promiscuous mating and dominance hierarchy among males (C. rutilus and M. meridianus, SEPS type II). A trade-off, or negative correlation, was found in M. arvalis-aspecies with weak pair bonds and male competition for receptive females (SEPS type III). In species with persistent pair bonds and structured family groups (L. Mandarinus and M. unguiculatus, SEPS type IV), no inverse relationship between the secretion of testosterone and paternal behavior was found either. Moreover, in male L. Mandarinus androgens appear to stimulate paternal care. PMID:25510112

  10. Uptake and distribution of radioiodine, and the effect of ambient nitrate, in some fish species.

    PubMed

    Lahti, E; Harri, M; Lindqvist, O V

    1985-01-01

    125I uptake by the thyroid was most pronounced in the smelt (Osmerus eperlanus), perch (Perca fluviatilis), rainbow trout (Salmo gairdneri), roach (Rutilus rutilus) and bleak (Alburnus alburnus). Unlike other tissues, only the muscle in the species studied no relative accumulation of 125I as compared to the ambient water. The Crusian carp (Cyprinus carassius) indicated the lowest levels of accumulation of 125I among the species tested. Thyroid radioiodine concentration was independent of the length of the fish in the rainbow trout and perch. In the rainbow trout, however, the liver and muscle radioiodine concentrations decreased significantly with increasing length of the fish. Exposure of rainbow trout to water containing supranormal concentration of nitrate (1500 micrograms/l) resulted in lowered 125I uptake. The same phenomenon was observed for the perch and Crusian carp, with low nitrate concentrations, while with higher nitrate concentrations, the uptake levels were again increased. Thyroid function, as judged from the conversion ratio and T/S ratio, was not affected by nitrate. PMID:2858311

  11. Biology of Amur sleeper (Perccottus glehni) in the Delta of the Selenga River, Buryatia, Russia

    USGS Publications Warehouse

    Litvinov, Alexander G.; O'Gorman, Robert

    1996-01-01

    We determined the fecundity, growth, diet, and density of the Amur sleeper (Perccottus glehni) in the Selenga River Delta on Lake Baikal during 1986-1991 to better understand how this invading exotic will affect Baikal's endemic fishes. We also compared the Amur sleeper's diet with that of other fishes living in the delta. The largest Amur sleepers were about 200 mm long and weighed 200 g; the oldest were age 7. All females were mature at age 2. Fecundity ranged from 884 eggs at age 1 to 37,056 eggs at age 7. Highest densities of Amur sleepers were found in oxbow lakes where densities sometimes exceeded 4,000 fish per ha. The bulk of the diet of Amur sleeper age 2 and older was chironomids, fish, and fish eggs. Chironomids were also important in the diet of the commercially valuable Siberian roach (Rutilus rutilus lacustris) and Siberian dace (Leuciscus leuciscus baicalensis). Thus the Amur sleeper may cause population declines of these important endemic fishes through resource competition and predation on their juvenile life stages. However, Amur sleepers were the species of fish most frequently eaten by Eurasian perch (Perca fluviatilis) and northern pike (Esox lucius). So, maintaining vigorous populations of these two predators may well be an effective strategy for limiting the size of Amur sleeper populations.

  12. First detection of circovirus-like sequences in amphibians and novel putative circoviruses in fishes.

    PubMed

    Tarján, Zoltán László; Pénzes, Judit J; Tóth, Róza P; Benkő, Mária

    2014-03-01

    The negative samples of a collection, established originally for seeking new adeno- and herpesviruses in lower vertebrates, were screened for the pres-ence of circoviruses by a consensus nested PCR targeting the gene coding for the replication-associated protein. Six fish samples representing five species, namely asp (Aspius aspius), roach (Rutilus rutilus), common bream (Abramis brama), round goby (Neogobius melanostomus) and monkey goby (Neogobius fluviatilis), as well as three frog samples were found positive for circoviral DNA. Sequence analysis of the amplicons indicated the presence of three novel putative circo-like viruses and a circovirus in Hungarian fishes and one novel circovirus in a common toad (Bufo bufo), and another one in a dead and an alive specimen of green tree frog (Litoria caerulea), respectively. In phylogeny reconstruction, the putative bream circovirus clustered together with circoviruses discovered in other cyprinid fishes recently. Three other piscine circoviral sequences appeared closest to sequences derived from different environmental samples. Surprisingly, the nucleotide sequence derived from two fish samples (a bream and a monkey goby) proved to be from porcine circovirus 2 (PCV2), almost identical to a sequence detected in Sweden previously. This is the first report on the detection of PCV2 in fish and circoviral DNA in amphibian hosts. PMID:24334078

  13. Hybridisation between two cyprinid fishes in a novel habitat: genetics, morphology and life-history traits

    PubMed Central

    2010-01-01

    Background The potential role hybridisation in adaptive radiation and the evolution of new lineages has received much recent attention. Hybridisation between roach (Rutilus rutilus L.) and bream (Abramis brama L.) is well documented throughout Europe, however hybrids in Ireland occur at an unprecedented frequency, often exceeding that of both parental species. Utilising an integrated approach, which incorporates geometric morphometrics, life history and molecular genetic analyses we identify the levels and processes of hybridisation present, while also determining the direction of hybridisation, through the analysis of mitochondrial DNA. Results The presence of F2 hybrids was found to be unlikely from the studied populations, although significant levels of backcrossing, involving both parental taxa was observed in some lakes. Hybridisation represents a viable conduit for introgression of genes between roach and bream. The vast majority of hybrids in all populations studied exhibited bream mitochondrial DNA, indicating that bream are maternal in the majority of crosses. Conclusions The success of roach × bream hybrids in Ireland is not due to a successful self reproducing lineage. The potential causes of widespread hybridisation between both species, along with the considerations regarding the role of hybridisation in evolution and conservation, are also discussed. PMID:20529364

  14. Differential Hepatic Metal and Metallothionein Levels in Three Feral Fish Species along a Metal Pollution Gradient

    PubMed Central

    Bervoets, Lieven; Knapen, Dries; De Jonge, Maarten; Van Campenhout, Karen; Blust, Ronny

    2013-01-01

    The accumulation of cadmium, copper and zinc and the induction of metallothioneins (MT) in liver of three freshwater fish species was studied. Gudgeon (Gobio gobio), roach (Rutilus rutilus) and perch (Perca fluviatilis) were captured at 6 sampling sites along a cadmium and zinc gradient and one reference site in a tributary of the Scheldt River in Flanders (Belgium). At each site up to 10 individuals per species were collected and analyzed on their general condition factor (K), hepatosomatic index (HSI) and gonadosomatic index (GSI). From each individual fish the liver was dissected and analyzed on Cd, Cu and Zn and MT-content. Although not all species were present at each site, hepatic Cd and Zn levels generally followed the pollution gradient and highest levels were measured in perch, followed by roach and gudgeon. Nevertheless also an effect of site was observed on this order. MT-levels appeared to be the highest in gudgeon although differences with the other species were not very pronounced and depended on the site. Significant relationships were found between hepatic zinc accumulation and MT levels. For each species the ratio MTtheoretical/ MTmeasured was calculated, which gives an indication of the relative capacity to induce MTs and thus immobilize the metals. Perch had the lowest capacity in inducing MTs (highest ratio). Relationships between hepatic metal levels and fish condition indices were absent or very weak. PMID:23556004

  15. Influence of the cestode Ligula intestinalis and the acanthocephalan Polymorphus minutus on levels of heat shock proteins (HSP70) and metallothioneins in their fish and crustacean intermediate hosts.

    PubMed

    Frank, Sabrina N; Godehardt, Saskia; Nachev, Milen; Trubiroha, Achim; Kloas, Werner; Sures, Bernd

    2013-09-01

    It is a common method to analyse physiological mechanisms of organisms - commonly referred to as biomarkers - to indicate the presence of environmental pollutants. However, as biomarkers respond to a wide range of stressors we want to direct the attention on natural stressors, i.e. on parasites. After two years maintenance under controlled conditions, roach (Rutilus rutilus) revealed no influence on levels of metallothionein by the parasite Ligula intestinalis. The same was found for Gammarus fossarum infected with Polymorphus minutus. However, the heat shock protein (HSP70) response was affected in both host-parasite systems. While the infection of roach resulted in reduced levels of HSP70 compared to uninfected roach, the infection in G.fossarum led to higher levels of HSP70. We also analysed the effect of a 14 days Cd exposure (4?g/L) on the uninfected and infected gammarids. The exposure resulted in induced levels for both, metallothionein and HSP70 whereas the combination of stressors, parasite and exposure, revealed a decrease for levels of HSP70 in comparison to the metal exposure only. Accordingly, parasites as natural parts of aquatic ecosystems have to be considered in ecotoxicological research. PMID:23770459

  16. Multiresidue method to quantify pesticides in fish muscle by QuEChERS-based extraction and LC-MS/MS.

    PubMed

    Lazartigues, Anglique; Wiest, Laure; Baudot, Robert; Thomas, Marielle; Feidt, Cyril; Cren-Oliv, Ccile

    2011-06-01

    Pesticide residues in fish muscle are an environmental and a health safety concern which requires analytical methods presenting high sensitivity and low limits of quantification. In this study, adapted QuEChERS method, coupled to liquid chromatography tandem mass spectrometry (Scheduled MRM-5500 QTRAP), was developed to quantify 13 pesticides (azoxystrobin, clomazone, diflufenican, dimethachlor, carbendazim, iprodion, isoproturon, mesosulfuron-methyl, metazachlor, napropamid, quizalofop and thifensulfuron-methyl) in muscle of fish. Quantification limits were below 1 ng g(-1) except for clomazone (1.8 ng g(-1)) and quizalofop (7.4 ng g(-1)). Best recoveries were observed for perch (>80%) and roach (>68%), except for thifensulfuron-methyl. Lower recoveries had been observed for carp (6% to 86%). Relative standard deviation was lower than 28% for intra-day and 29% for inter-day analysis, respectively. This method was successfully tested on three fish species, naturally or orally exposed: roach (Rutilus rutilus), perch (Perca fluviatilis) and carp (Cyprinus carpio). Few levels were observed in fish naturally exposed, but carp and perch orally contaminated showed measurable levels in their muscles. PMID:21484246

  17. Cross-Species Extrapolation of Uptake and Disposition of Neutral Organic Chemicals in Fish Using a Multispecies Physiologically-Based Toxicokinetic Model Framework.

    PubMed

    Brinkmann, Markus; Schlechtriem, Christian; Reininghaus, Mathias; Eichbaum, Kathrin; Buchinger, Sebastian; Reifferscheid, Georg; Hollert, Henner; Preuss, Thomas G

    2016-02-16

    The potential to bioconcentrate is generally considered to be an unwanted property of a substance. Consequently, chemical legislation, including the European REACH regulations, requires the chemical industry to provide bioconcentration data for chemicals that are produced or imported at volumes exceeding 100 tons per annum or if there is a concern that a substance is persistent, bioaccumulative, and toxic. For the filling of the existing data gap for chemicals produced or imported at levels that are below this stipulated volume, without the need for additional animal experiments, physiologically-based toxicokinetic (PBTK) models can be used to predict whole-body and tissue concentrations of neutral organic chemicals in fish. PBTK models have been developed for many different fish species with promising results. In this study, we developed PBTK models for zebrafish (Danio rerio) and roach (Rutilus rutilus) and combined them with existing models for rainbow trout (Onchorhynchus mykiss), lake trout (Salvelinus namaycush), and fathead minnow (Pimephales promelas). The resulting multispecies model framework allows for cross-species extrapolation of the bioaccumulative potential of neutral organic compounds. Predictions were compared with experimental data and were accurate for most substances. Our model can be used for probabilistic risk assessment of chemical bioaccumulation, with particular emphasis on cross-species evaluations. PMID:26794144

  18. Sources of variation in oxygen consumption of aquatic animals demonstrated by simulated constant oxygen consumption and respirometers of different sizes.

    PubMed

    Svendsen, M B S; Bushnell, P G; Christensen, E A F; Steffensen, J F

    2016-01-01

    As intermittent-flow respirometry has become a common method for the determination of resting metabolism or standard metabolic rate (SMR), this study investigated how much of the variability seen in the experiments was due to measurement error. Experiments simulated different constant oxygen consumption rates (M˙O2 ) of a fish, by continuously injecting anoxic water into a respirometer, altering the injection rate to correct for the washout error. The effect of respirometer-to-fish volume ratio (RFR) on SMR measurement and variability was also investigated, using the simulated constant M˙O2 and the M˙O2 of seven roach Rutilus rutilus in respirometers of two different sizes. The results show that higher RFR increases measurement variability but does not change the mean SMR established using a double Gaussian fit. Further, the study demonstrates that the variation observed when determining oxygen consumption rates of fishes in systems with reasonable RFRs mainly comes from the animal, not from the measuring equipment. PMID:26768971

  19. Catalasic activity in fish liver: improvement of the UV to visible analytic method.

    PubMed

    Paris-Palacios, Séverine; Delahaut, Laurence; Carreras, Alexis; Thomas, Marielle; Biagianti-Risbourg, Sylvie

    2013-08-01

    Antioxidative defenses and more especially catalasic activity (CAT) are studied in a large range of scientific research thematics. In environmental sciences, the problematic of oxidative stress is of great interest as pollutants can induce perturbations of redox homeostasis. Consequently, changes in antioxidative defenses levels in fish tissues and particularly in liver are used as potential biomarkers of pollution. In most studies, the CAT was assayed by following during 5 min the consumption of H2O2 in cytosolic buffered extracts at 240 nm (UV-method). This study proposed a development of this method in the visible, using permanganate and a 525-nm detection, which was more accurate, sensitive, and rapid. Moreover, the hepatic CAT of six different fish species [a cyclidae (Nimbochromis linni), 3 cyprinidae (Brachydanio rerio, Rutilus rutilus, Cyprinus carpio), an anguillidae (Anguilla anguilla), and a percidae (Perca fluviatilus)] was evaluated with the two protocols (UV- and KMnO4-method). The results but also the thermal optimum of the reaction and the interest of CAT as biomarker in ecotoxicology were discussed. PMID:23224832

  20. Additional treatment of wastewater reduces endocrine disruption in wild fish--a comparative study of tertiary and advanced treatments.

    PubMed

    Baynes, Alice; Green, Christopher; Nicol, Elizabeth; Beresford, Nicola; Kanda, Rakesh; Henshaw, Alan; Churchley, John; Jobling, Susan

    2012-05-15

    Steroid estrogens are thought to be the major cause of feminization (intersex) in wild fish. Widely used wastewater treatment technologies are not effective at removing these contaminants to concentrations thought to be required to protect aquatic wildlife. A number of advanced treatment processes have been proposed to reduce the concentrations of estrogens entering the environment. Before investment is made in such processes, it is imperative that we compare their efficacy in terms of removal of steroid estrogens and their feminizing effects with other treatment options. This study assessed both steroid removal and intersex induction in adult and early life stage fish (roach, Rutilus rutilus). Roach were exposed directly to either secondary (activated sludge process (ASP)), tertiary (sand filtrated (SF)), or advanced (chlorine dioxide (ClO(2)), granular activated charcoal (GAC)) treated effluents for six months. Surprisingly, both the advanced GAC and tertiary SF treatments (but not the ClO(2) treatment) significantly removed the intersex induction associated with the ASP effluent; this was not predicted by the steroid estrogen measurements, which were higher in the tertiary SF than either the GAC or the ClO(2). Therefore our study highlights the importance of using both biological and chemical analysis when assessing new treatment technologies. PMID:22500691

  1. First evidence of fish genotoxicity induced by heavy metals from landfill leachates: the advantage of using the RAPD-PCR technique.

    PubMed

    Ben Salem, Zohra; Capelli, Nicolas; Grisey, Elise; Baurand, Pierre-Emmanuel; Ayadi, Habib; Aleya, Lotfi

    2014-03-01

    Municipal leachates are loaded with heavy metals that can contaminate surface water before discharge into a receiving body of water. The aim of this study is to evaluate the genotoxic effects of heavy metals generated by domestic waste on the common roach Rutilus rutilus in the last of the four interconnected ponds at the Etueffont landfill. We used random amplified polymorphic DNA (RAPD) since it has been shown to be a powerful means of detecting a broad range of DNA damage due to environmental contaminants. Our results show the ability of RAPD analysis to detect significant genetic alterations in roach DNA, after contamination with a set of metals contained in the landfill leachates in comparison to a roach from a non-polluted reference pond. Analysis of electrophoresis profiles indicates apparent changes such as the appearance of new bands or disappearance of bands as compared to the control. In fact, mixed smearing and laddering of DNA fragments in muscle samples support the genotoxic effects of metal deposits in the roach. This study is the first evidence found via the RAPD-PCR technique in the detection of pollutant impacts on fish exposed to landfill leachates. PMID:24507132

  2. The impact of fish predation on shallow soft bottoms in brackish waters (SW Finland); an experimental study

    NASA Astrophysics Data System (ADS)

    Mattila, J.; Bonsdorff, E.

    The impact of fish predation on shallow soft bottoms was studied by field and laboratory experiments. The field manipulations (caging experiments) were carried out in 2 shallow (1.5 m) bays in the northern Baltic Sea. An a priori hypothesis that fish do not structure macrozoobenthic communities in shallow soft-bottom areas was tested. Short-term aquarium experiments clearly showed that perch ( Perca fluviatilis L.), roach ( Rutilus rutilus L.) and ruffe ( Acerina cernua (L.)) are all effective predators on benthic macroinvertebrates ( Corophium volutator) Pallas and Nereis diversicolor O.F. Müller) under laboratory conditions. Thus fish can be considered a potential structuring force on benthic communities in shallow soft-bottom areas. Caging experiments of one to two month's duration (partial and total exclosure of fish and enclosure with perch) induced only minor changes in the benthic community. These results support the a priori hypothesis. One of our main conclusions is, however, that fish predation and other biotic interactions (competition, disturbance, etc.) together with abiotic factors play some role in the structuring processes. Multilevel testing is needed in studies on biotic interactions in the marine environment. Results from a specific environment should not automatically be applied to other kinds of habitats.

  3. Shoreline development and degradation of coastal fish reproduction habitats.

    PubMed

    Sundblad, Göran; Bergström, Ulf

    2014-12-01

    Coastal development has severely affected habitats and biodiversity during the last century, but quantitative estimates of the impacts are usually lacking. We utilize predictive habitat modeling and mapping of human pressures to estimate the cumulative long-term effects of coastal development in relation to fish habitats. Based on aerial photographs since the 1960s, shoreline development rates were estimated in the Stockholm archipelago in the Baltic Sea. By combining shoreline development rates with spatial predictions of fish reproduction habitats, we estimated annual habitat degradation rates for three of the most common coastal fish species, northern pike (Esox lucius), Eurasian perch (Perca fluviatilis) and roach (Rutilus rutilus). The results showed that shoreline constructions were concentrated to the reproduction habitats of these species. The estimated degradation rates, where a degraded habitat was defined as having ≥3 constructions per 100 m shoreline, were on average 0.5 % of available habitats per year and about 1 % in areas close to larger population centers. Approximately 40 % of available habitats were already degraded in 2005. These results provide an example of how many small construction projects over time may have a vast impact on coastal fish populations. PMID:24943864

  4. The influence of environmental factors on movements of lowland-river fish in the Yorkshire Ouse system.

    PubMed

    Lucas, M C

    2000-05-01

    The influence of several environmental parameters on movements of fish within the Yorkshire Ouse system, north-east England, is considered. Automated monitoring of fish with passive integrated transponding (PIT) tags, at the entrance to a fish pass on the lower Derwent, was used to examine factors influencing upstream migration of fish between May and August 1998. Overall, 85% of records were from the cyprinids, chub Leuciscus cephalus, dace Leuciscus leuciscus and roach Rutilus rutilus, which are the dominant species in the lower Derwent. Daily numbers of PIT-tagged fish entering the pass in summer were significantly and positively correlated with daylength, but not significantly correlated with mean daily temperature or mean daily flow. There were significant variations in the diel pattern of PIT records between species. Adult chub mostly approached the fish pass at night, while other species entered over a wider range of times, and stocked juvenile cyprinids entered mostly during daytime. Analyses of movements of radio-tracked barbel from the lower Nidd showed that downstream displacements associated with high flow in summer were often followed by homing to the original residence area, but that in autumn displacements were significantly more frequent and homing was significantly less frequent, resulting in a tendency for barbel to move downstream. It is concluded that an appreciation of the effects of environmental parameters on movements by different fish species is important in understanding the causation of spatial variations in distribution of fish in lowland rivers. PMID:10847163

  5. Diel variations in the assemblage structure and foraging ecology of larval and 0+ year juvenile fishes in a man-made floodplain waterbody.

    PubMed

    Tewson, L H; Cowx, I G; Nunn, A D

    2016-04-01

    This study investigated diel variations in zooplankton composition and abundance, and the species composition, density, size structure, feeding activity, diet composition and prey selection of larval and 0+ year juvenile fishes in the littoral of a man-made floodplain waterbody over five 24 h periods within a 57 day period. There was a significant difference in the species composition of diurnal and nocturnal catches, with most species consistently peaking in abundance either during daylight or at night, reflecting their main activity period. There were no consistent diel patterns in assemblage structure or the abundance of some species, however, most likely, respectively, due to the phenology of fish hatching and ontogenetic shifts in diel behaviour or habitat use. There were few clear diel patterns in the diet composition or prey selection of larval and 0+ year juvenile roach Rutilus rutilus and perch Perca fluviatilis, with most taxa consistently selected or avoided irrespective of the time of day or night, and no obvious shift between planktonic and benthic food sources, but dietary overlap suggested that interspecific interactions were probably strongest at night. It is essential that sampling programmes account for the diel ecology of the target species, as diurnal surveys alone could produce inaccurate assessments of resource use. The relative lack of consistent diel patterns in this study suggests that multiple 24 h surveys are required in late spring and early summer to provide accurate assessments of 0+ year fish assemblage structure and foraging ecology. PMID:26935792

  6. Use Carum copticum essential oil for controlling the Listeria monocytogenes growth in fish model system

    PubMed Central

    Rabiey, Soghra; Hosseini, Hedayat; Rezaei, Masoud

    2014-01-01

    This study was conducted to evaluate the antibacterial effect of Carum copticum essential oil (Ajowan EO) against Listeria monocytogenes in fish model system. Ajowan EO chemical composition was determined by gas chromatography/mass spectral analysis and the highest concentration of Carum copticum essential oil without any significant changes on sensory properties of kutum fish (Rutilus frisii kutum) was assigned. Then the inhibitory effect of Ajowan EO at different concentrations in presence of salt and smoke component was tested on L. monocytogenes growth in fish peptone broth (FPB), kutum broth and cold smoked kutum broth at 4 °C for 12 days. Ajowan EO completely decreased the number of L. monocytogenes in FPB after 12 days of storage, however, antimicrobial effect of EO significantly reduced in kutum and cold smoked kutum broth. Addition of 4% NaCl and smoke component improved the anti-listerial activity of Ajowan EO in all fish model broths. PMID:24948918

  7. DNA adducts in marine mussel and fresh water fishes living in polluted and unpolluted environments

    SciTech Connect

    Kurelec, B.; Checko, M.; Krca, S.; Garg, A.; Gupta, R.C. Baylor College of Medicine, Houston, TX )

    1988-09-01

    {sup 32}P-postlabeling analysis of DNA adducts in the digestive gland of marine mussel Mytilus galloprovincialis from polluted and unpolluted sites near Rovinj, Northern Adriatic, revealed that majority of adducts are caused by natural environmental factors rather than by man-made chemicals. The only pollutant-specific adducts were observed in a mussel exposed to seawater experimentally polluted with aminofluorene, and in a population of mussel living at a site heavily polluted with a waste waters of an oil refinery. Fresh water fish species Leuciscus cephalus, Barbus barbus, Abramis brama and Rutilus pigus virgo living in a polluted Sava River, Yugoslavia, or in its unpolluted tributary Korana River, have induced in their livers qualitatively identical and quantitatively similar DNA adducts. These DNA adducts had a species-specific patterns and their appearance was seasonally-dependent.

  8. Biodiversity of trematodes in their intermediate mollusc and fish hosts in the freshwater ecosystems of Europe.

    PubMed

    Faltýnková, Anna; Sures, Bernd; Kostadinova, Aneta

    2016-03-01

    We analysed two novel databases containing 2,380 and 8,202 host-parasite-locality records for trematode parasites of molluscs and fishes, respectively, to assess the biodiversity of trematodes in their intermediate mollusc and fish hosts in the freshwater environment in Europe. The "mollusc" dataset covers large numbers of pulmonate (29 spp.), "prosobranch" (15 spp.) and bivalve (11 spp.) molluscs acting as first intermediate hosts for 171 trematode species of 89 genera and 35 families. Of these, 23 and 40 species utilise freshwater fishes as definitive and second intermediate hosts, respectively. The most frequently recorded families are the Echinostomatidae Looss, 1899, Diplostomidae Poirier, 1886 and Schistosomatidae Stilles & Hassal, 1898, and the most frequently recorded species are Diplostomum spathaceum (Rudolphi, 1819), D. pseudospathaceum Niewiadomska, 1984 and Echinoparyphium recurvatum (von Linstow, 1873). Four snail species harbour extremely rich trematode faunas: Lymnaea stagnalis (L.) (41 spp.); Planorbis planorbis (L.) (39 spp.); Radix peregra (O.F. Müller) (33 spp.); and R. ovata (Draparnaud) (31 spp.). The "fish" dataset covers 99 fish species of 63 genera and 19 families acting as second intermediate hosts for 66 species of 33 genera and nine families. The most frequently recorded families are the Diplostomidae Poirier, 1886, Strigeidae Railliet, 1919 and Bucephalidae Poche, 1907, and the most frequently recorded species are Diplostomum spathaceum (Rudolphi, 1819), Tylodelphys clavata (von Nordmann, 1832) and Posthodiplostomum cuticola (von Nordmann, 1832). Four cyprinid fishes exhibit the highest species richness of larval trematodes: Rutilus rutilus (L.) (41 spp.); Abramis brama (L.) (34 spp.); Blicca bjoerkna (L.) (33 spp.); and Scardinius erythrophthalmus (L.) (33 spp.). Larval stages of 50 species reported in fish are also reported in freshwater molluscs, thus indicating a relatively good knowledge of the life-cycles of fish trematodes in Europe. We provide host-parasite lists for 55 species of molluscs with a European distribution comprising 413 host-parasite associations. PMID:26898591

  9. A Mixed-Method Approach for Quantifying Illegal Fishing and Its Impact on an Endangered Fish Species

    PubMed Central

    Free, Christopher M.; Jensen, Olaf P.; Mendsaikhan, Bud

    2015-01-01

    Illegal harvest is recognized as a widespread problem in natural resource management. The use of multiple methods for quantifying illegal harvest has been widely recommended yet infrequently applied. We used a mixed-method approach to evaluate the extent, character, and motivations of illegal gillnet fishing in Lake Hovsgol National Park, Mongolia and its impact on the lake’s fish populations, especially that of the endangered endemic Hovsgol grayling (Thymallus nigrescens). Surveys for derelict fishing gear indicate that gillnet fishing is widespread and increasing and that fishers generally use 3–4 cm mesh gillnet. Interviews with resident herders and park rangers suggest that many residents fish for subsistence during the spring grayling spawning migration and that some residents fish commercially year-round. Interviewed herders and rangers generally agree that fish population sizes are decreasing but are divided on the causes and solutions. Biological monitoring indicates that the gillnet mesh sizes used by fishers efficiently target Hovsgol grayling. Of the five species sampled in the monitoring program, only burbot (Lota lota) showed a significant decrease in population abundance from 2009–2013. However, grayling, burbot, and roach (Rutilus rutilus) all showed significant declines in average body size, suggesting a negative fishing impact. Data-poor stock assessment methods suggest that the fishing effort equivalent to each resident family fishing 50-m of gillnet 11–15 nights per year would be sufficient to overexploit the grayling population. Results from the derelict fishing gear survey and interviews suggest that this level of effort is not implausible. Overall, we demonstrate the ability for a mixed-method approach to effectively describe an illegal fishery and suggest that these methods be used to assess illegal fishing and its impacts in other protected areas. PMID:26625154

  10. Assessing anthropogenic impact on boreal lakes with historical fish species distribution data and hydrogeochemical modeling

    PubMed Central

    Valinia, Salar; Englund, Göran; Moldan, Filip; Futter, Martyn N; Köhler, Stephan J; Bishop, Kevin; Fölster, Jens

    2014-01-01

    Quantifying the effects of human activity on the natural environment is dependent on credible estimates of reference conditions to define the state of the environment before the onset of adverse human impacts. In Europe, emission controls that aimed at restoring ecological status were based on hindcasts from process-based models or paleolimnological reconstructions. For instance, 1860 is used in Europe as the target for restoration from acidification concerning biological and chemical parameters. A more practical problem is that the historical states of ecosystems and their function cannot be observed directly. Therefore, we (i) compare estimates of acidification based on long-term observations of roach (Rutilus rutilus) populations with hindcast pH from the hydrogeochemical model MAGIC; (ii) discuss policy implications and possible scope for use of long-term archival data for assessing human impacts on the natural environment and (iii) present a novel conceptual model for interpreting the importance of physico-chemical and ecological deviations from reference conditions. Of the 85 lakes studied, 78 were coherently classified by both methods. In 1980, 28 lakes were classified as acidified with the MAGIC model, however, roach was present in 14 of these. In 2010, MAGIC predicted chemical recovery in 50% of the lakes, however roach only recolonized in five lakes after 1990, showing a lag between chemical and biological recovery. Our study is the first study of its kind to use long-term archival biological data in concert with hydrogeochemical modeling for regional assessments of anthropogenic acidification. Based on our results, we show how the conceptual model can be used to understand and prioritize management of physico-chemical and ecological effects of anthropogenic stressors on surface water quality. PMID:24535943

  11. How well can fishes prey on zebra mussels in eastern North America?

    USGS Publications Warehouse

    French, John R. P., III

    1993-01-01

    Literature on mollusk-eating fishes was reviewed to determine the potential for different species of fish to control zebra mussels in eastern North America. At least six species are potential predators of zebra mussels because they possess (1) both upper and lower pharyngeal teeth or (2) lower pharyngeal teeth and chewing pads located on the dorsal roof for crushing mollusk shells. Freshwater drum (Aplodinotus grunniens) and two centrarchids, redear sunfish (Lepomis microlophus) and pumpkinseed (L. gibbosus), possess both upper and lower pharyngeal teeth and are likely to consume more zebra mussels than fishes with only lower pharyngeal teeth. Only two catostomid species, copper and river redhorses (Moxostoma hubbsi and M. carinatum), have chewing pads that enable them to crush mollusks. The exotic omnivorous common carp (Cyprinus carpio), possessing lower teeth and a chewing pad, may prey on zebra mussels when aquatic insect larvae, its preferred food, become rare. Managing populations of drum, sunfishes and redhorses to reduce exploitation of large individuals and improve their habitats are suggested as means to intensify biological control of zebra mussels in eastern North America. Other Eurasian molluscivores, the roach (Rutilus rutilus) and the black carp (Mylopharyngodon piceus) should not be introduced into North America because research has shown repeatedly that an introduced biological controller usually does not forage for unwanted pests or reside only in preferred habitats of pests. Drum, sunfishes and redhorses should be preferred over these exotics as biological controllers of zebra mussels in North America because these native fishes will likely occupy newly established habitats of zebra mussels.

  12. Biomonitoring of polychlorinated biphenyls (PCBs) in heavily polluted aquatic environment in different fish species.

    PubMed

    Brzov, Tmea; Hanzelov, Vladimra; Miklisov, Dana; algovi?ov, Danka; Tur?ekov, L'udmila

    2012-11-01

    The distribution and concentrations of polychlorinated biphenyls (PCBs) were determined in fish species (European perch Perca fluviatilis, northern pike Esox lucius, pike perch Sander lucioperca, wels catfish Silirus glanus, common carp Cyprinus carpio, European eel Anguilla anguilla, freshwater bream Abramis brama, goldfish Carassius auratus, and roach Rutilus rutilus) in a heavily polluted water reservoir Zemplnska rava (Slovakia). The study performed at two different time points 5 years apart (2004 and 2009) revealed serious PCB contamination of fish muscle tissue and significant interspecies as well as tissue-specific differences in PCB uptake by fish. Total PCBs broadly correlated with the trophic position of individual fish species within a food chain (P < 0.01). The concentrations were particularly high in predatory fish species, perch, pike, and pike perch (108.0, 90.1, and 113.0 mg kg(-1) lipid wt, respectively), but comparable PCB values were also found in non-predatory detrivorous freshwater bream (128.0 mg kg(-1) lipid wt). The lowest PCB values were surprisingly assessed in European eel (17.1 mg kg(-1) lipid wt). Tissue analysis showed the highest storage capacity of the liver (hepatopancreas in cyprinids) with maximum concentrations recorded found in northern pike (214.0 mg kg(-1) lipid wt) and freshwater bream (163.0 mg kg(-1) lipid wt). Negative correlations, mostly not significant, between the total PCB concentrations and fish weight were observed (P > 0.05). The study has shown that the kind of fish, its feeding habit, and specific conditions of the habitat are mutually interrelated factors that are responsible for significant variations in fish body burdens. A tendency to PCB biomagnification was also proved in some fish species of this water reservoir. PMID:22173787

  13. Transferability of predictive fish distribution models in two coastal systems

    NASA Astrophysics Data System (ADS)

    Sundblad, Gran; Hrm, Meri; Lappalainen, Antti; Urho, Lauri; Bergstrm, Ulf

    2009-06-01

    Species distribution modelling has emerged as a tool both for exploring niche theory and for producing distribution maps for management. To understand and predict potential effects of large scale habitat change there is a need for proper model validation and applicability also in unstudied areas. However, knowledge about factors influencing the transferability of distribution models, i.e. the accuracy of the models when applying them in a new geographical area, is limited. We have successfully modelled the larval distribution of two fish species, northern pike ( Esox lucius L.) and roach ( Rutilus rutilus L.), on a regional scale in the Baltic Sea using a few and easily measured environmental variables. When models were transferred from the training area to the testing area the models showed reasonable to very good discrimination (ROC 0.75 and 0.93) based on external validation using independent data separated also in time (1-2 years). The predicted larval distribution also overlapped with the distribution of young-of-the-year fish later in the season. Performance when reversing the transfer, by constructing the models in the testing area and predicting back to the original training area, was less successful. This discrepancy was species-specific and could be explained by differences in the species presence ranges along the predictor variables in the testing area compared to the training area. Our results illustrate how transferability success can be influenced by area-specific differences in the range of the predictor variables and show the necessity of validating model predictions properly.

  14. Differences in the activities of eight enzymes from ten soil fungi and their possible influences on the surface structure, functional groups, and element composition of soil colloids.

    PubMed

    Wang, Wenjie; Li, Yanhong; Wang, Huimei; Zu, Yuangang

    2014-01-01

    How soil fungi function in soil carbon and nutrient cycling is not well understood by using fungal enzymatic differences and their interactions with soil colloids. Eight extracellular enzymes, EEAs (chitinase, carboxymethyl cellulase, β-glucosidase, protease, acid phosphatase, polyphenol oxidase, laccase, and guaiacol oxidase) secreted by ten fungi were compared, and then the fungi that showed low and high enzymatic activity were co-cultured with soil colloids for the purpose of finding fungi-soil interactions. Some fungi (Gomphidius rutilus, Russula integra, Pholiota adiposa, and Geastrum mammosum) secreted 3-4 enzymes with weak activities, while others (Cyathus striatus, Suillus granulate, Phallus impudicus, Collybia dryophila, Agaricus sylvicola, and Lactarius deliciosus) could secret over 5 enzymes with high activities. The differences in these fungi contributed to the alterations of functional groups (stretching bands of O-H, N-H, C-H, C = O, COO- decreased by 11-60%, while P = O, C-O stretching, O-H bending and Si-O-Si stretching increased 9-22%), surface appearance (disappearance of adhesive organic materials), and elemental compositions (11-49% decreases in C1s) in soil colloids. Moreover, more evident changes were generally in high enzymatic fungi (C. striatus) compared with low enzymatic fungi (G. rutilus). Our findings indicate that inter-fungi differences in EEA types and activities might be responsible for physical and chemical changes in soil colloids (the most active component of soil matrix), highlighting the important roles of soil fungi in soil nutrient cycling and functional maintenance. PMID:25398013

  15. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France.

    PubMed

    Certad, Gabriela; Dupouy-Camet, Jean; Gantois, Nausicaa; Hammouma-Ghelboun, Ourida; Pottier, Muriel; Guyot, Karine; Benamrouz, Sadia; Osman, Marwan; Delaire, Baptiste; Creusy, Colette; Viscogliosi, Eric; Dei-Cas, Eduardo; Aliouat-Denis, Cecile Marie; Follet, Jérôme

    2015-01-01

    Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the observation of edible fillet contamination. PMID:26213992

  16. Karyotypes, male meiosis and comparative FISH mapping of 18S ribosomal DNA and telomeric (TTAGG) n repeat in eight species of true bugs (Hemiptera, Heteroptera)

    PubMed Central

    Grozeva, S.; Kuznetsova, V.G.; Anokhin, B.A.

    2011-01-01

    Abstract Eight species belonging to five true bug families were analyzed using DAPI/CMA3-staining and fluorescence in situ hybridization (FISH) with telomeric (TTAGG)n and 18S rDNA probes. Standard chromosomal complements are reported for the first time for Deraeocoris rutilus (Herrich-Schäffer, 1838) (2n=30+2m+XY) and Deraeocoris ruber(Linnaeus, 1758) (2n=30+2m+XY) from the family Miridae. Using FISH, the location of a 18S rDNA cluster was detected in these species and in five more species: Megaloceroea recticornis (Geoffroy, 1785) (2n=30+XY) from the Miridae; Oxycarenus lavaterae (Fabricius, 1787) (2n=14+2m+XY) from the Lygaeidae s.l.; Pyrrhocoris apterus (Linnaeus, 1758) (2n=22+X) from the Pyrrhocoridae; Eurydema oleracea (Linnaeus, 1758) (2n=12+XY) and Graphosoma lineatum (Linnaeus, 1758) (2n=12+XY) from the Pentatomidae. The species were found to differ with respect to location of a 18S rRNA gene cluster which resides on autosomes in Oxycarenus lavaterae and Pyrrhocoris apterus, whereas it locates on sex chromosomes in other five species. The 18S rDNA location provides the first physical landmark of the genomes of the species studied. The insect consensus telomeric pentanucleotide (TTAGG)n was demonstrated to be absent in all the species studied in this respect, Deraeocoris rutilus, Megaloceroea recticornis, Cimex lectularius Linnaeus, 1758 (Cimicidae), Eurydema oleracea, and Graphosoma lineatum, supporting the hypothesis that this motif was lost in early evolution of the Heteroptera and secondarily replaced with another motif (yet unknown) or the alternative telomerase-independent mechanisms of telomere maintenance. Dot-blot hybridization analysis of the genomic DNA from Cimex lectularius, Nabis sp. and Oxycarenus lavaterae with (TTAGG)n and six other telomeric probes likewise provided a negative result. PMID:24260641

  17. The occurrence of metacercariae of Petasiger (Digenea: Echinostomatidae) in an unusual site, within the lateral line scales of cyprinid fishes.

    PubMed

    Molnar, Kalman; Gibson, David I; Cech, Gabor; Papp, Melitta; Deak-Paulus, Petra; Juhasz, Lajos; Toth, Norbert; Szekely, Csaba

    2015-01-01

    During a regular veterinary inspection of fishes from Lake Balaton, Hungary, echinostomatid metacercariae (Digenea), with collar spines characteristic of species of the genera Petasiger Dietz, 1909 and Paryphostomum Dietz, 1909, were found in the lateral line scales of a roach Rutilus rutilus (Linnaeus), an apparently unique site. In a subsequent examination of 586 fishes from 20 different species, similar infections were found in 11 species. The infection was virtually restricted to the lateral line scales, other scales being infected only incidentally. These encysted metacercariae had 27 collar spines, including eight larger angle spines and 19 smaller dorsal spines arranged in two rows. Two types of metacercarial cyst were found. One type had a cyst diameter of 138-171 µm × 105-120 µm and three central dorsal spines that were larger than the remainder and tended to resemble the angle spines. The second type of metacercarial cyst had a diameter of 128-157 µm × 105-115 µm and all 19 dorsal spines of the metacercaria were of a similar size. ITS sequences of the second type of metacercaria exhibited a 100% similarity to sequences of two adult Petasiger phalacrocoracis (Yamaguti, 1939) specimens collected from the gut of Phalacrocorax carbo (Linnaeus) in Hungary and to P. phalacrocoracis deposited in the GenBank database. Sequences obtained from two metacercariae of the first type showed a 2.8-2.9 % difference from sequences of the second type of metacercaria and from those of adult specimens of P. phalacrocoracis from cormorants. Based on these results, the second type metacercaria is considered to be a larval stage of P. phalacrocoracis, but the identity of the first type is uncertain. The unusual location of these metacercariae in the lateral line scales is discussed in relation to their transmission. PMID:25960561

  18. Populations of a cyprinid fish are self-sustaining despite widespread feminization of males

    PubMed Central

    2014-01-01

    Background Treated effluents from wastewater treatment works can comprise a large proportion of the flow of rivers in the developed world. Exposure to these effluents, or the steroidal estrogens they contain, feminizes wild male fish and can reduce their reproductive fitness. Long-term experimental exposures have resulted in skewed sex ratios, reproductive failures in breeding colonies, and population collapse. This suggests that environmental estrogens could threaten the sustainability of wild fish populations. Results Here we tested this hypothesis by examining population genetic structures and effective population sizes (Ne) of wild roach (Rutilus rutilus L.) living in English rivers contaminated with estrogenic effluents. Ne was estimated from DNA microsatellite genotypes using approximate Bayesian computation and sibling assignment methods. We found no significant negative correlation between Ne and the predicted estrogen exposure at 28 sample sites. Furthermore, examination of the population genetic structure of roach in the region showed that some populations have been confined to stretches of river with a high proportion of estrogenic effluent for multiple generations and have survived, apparently without reliance on immigration of fish from less polluted sites. Conclusions These results demonstrate that roach populations living in some effluent-contaminated river stretches, where feminization is widespread, are self-sustaining. Although we found no evidence to suggest that exposure to estrogenic effluents is a significant driving factor in determining the size of roach breeding populations, a reduction in Ne of up to 65% is still possible for the most contaminated sites because of the wide confidence intervals associated with the statistical model. PMID:24417977

  19. Light-mediated host searching strategies in a fish ectoparasite, Argulus foliaceus L. (crustacea: branchiura).

    PubMed

    Mikheev, V N; Mikheev, A V; Pasternak, A F; Valtonen, E T

    2000-04-01

    Argulus foliaceus, an obligate fish ectoparasite, can search for its hosts in both light and dark conditions and uses vision in the light. We have examined what searching mode is used at night, when the infection rate was at its highest, and which stimuli produced by the fish are most important. A change of illumination produced a clear difference in the searching behaviour of adult Argulus females. The mean swimming speed and the area explored were 3-4 times higher in the dark, when the parasite employed a cruising search strategy. This changed to an ambush (hover-and-wait) strategy in the light. The swimming activity is accompanied by changes in metabolic costs; the activity of the electron transport system being approximately 25 % lower in the light. The most pronounced light-induced differences in host-searching behaviour took place in moderately hungry parasites (starved for 24-96 h). Less motivated (just having left a fish) or exhausted animals did not exhibit any clear differences in swimming speed. Among the external signals tested, fish smell, from both perch (Perca fluviatilis) and roach (Rutilus rutilus), induced an elevated swimming speed of the parasite. Periodic water movements caused similar but weaker effects. The effects of these stimuli were observed under both light and dark conditions. We conclude that host-searching behaviour of A. foliaceus is under internal (state of hunger) and external (illumination and host-induced signals) control and involves all its sensory equipment (vision, olfaction and mechano-reception). Perch (but not roach) reduced their swimming speed in the dark, which make them more susceptible to cruising Argulus. Thus the behavioural interplay between hosts and parasites can also influence the infection rate of A. foliaceus found on perch and roach in Finnish lakes. PMID:10811282

  20. Strategies of zooplanktivory shape the dynamics and diversity of littoral plankton communities: a mesocosm approach

    PubMed Central

    Helenius, Laura K; Aymà Padrós, Anna; Leskinen, Elina; Lehtonen, Hannu; Nurminen, Leena

    2015-01-01

    Planktivorous fish can exert strong top-down control on zooplankton communities. By incorporating different feeding strategies, from selective particulate feeding to cruising filter feeding, fish species target distinct prey. In this study, we investigated the effects of two species with different feeding strategies, the three-spined stickleback (Gasterosteus aculeatus (L.)) and roach (Rutilus rutilus (L.)), on a low-diversity brackish water zooplankton community using a 16-day mesocosm experiment. The experiment was conducted on a small-bodied spring zooplankton community in high-nutrient conditions, as well as a large-bodied summer community in low-nutrient conditions. Effects were highly dependent on the initial zooplankton community structure and hence seasonal variation. In a small-bodied community with high predation pressure and no dispersal or migration, the selective particulate-feeding stickleback depleted the zooplankton community and decreased its diversity more radically than the cruising filter-feeding roach. Cladocerans rather than copepods were efficiently removed by predation, and their removal caused altered patterns in rotifer abundance. In a large-bodied summer community with initial high taxonomic and functional diversity, predation pressure was lower and resource availability was high for omnivorous crustaceans preying on other zooplankton. In this community, predation maintained diversity, regardless of predator species. During both experimental periods, predation influenced the competitive relationship between the dominant calanoid copepods, and altered species composition and size structure of the zooplankton community. Changes also occurred to an extent at the level of nontarget prey, such as microzooplankton and rotifers, emphasizing the importance of subtle predation effects. We discuss our results in the context of the adaptive foraging mechanism and relate them to the natural littoral community. PMID:26045953

  1. Epidemiology of fishborne trematodiasis in Kazakhstan.

    PubMed

    Sultanov, A; Abdybekova, A; Abdibaeva, A; Shapiyeva, Z; Yeshmuratov, T; Torgerson, P R

    2014-10-01

    Fish borne trematodes are an important cause of morbidity in Kazakhstan. The number of human cases of opisthorchiidosis (infection with parasites of the family opisthorchiidae) reached a peak of 2521 recorded cases (17 cases per 100,000) in 2002 with a gradual decline to 1225 cases (7.4 cases per 100,000) in 2011. Most human cases are found in the north and north east part of Kazakhstan in areas drained by the Irtysh River and it tributaries. A further focus is found in the north west in the Ural river basin in the European part of Kazakhstan. The most common occupations of patients with opisthorchiidosis included the manual laborers, those employed in the home or unemployed. Necropsy investigations of village dogs in an endemic region revealed 37 of 51 (72%) village dogs infected with either Opisthorchis felineus or Methorchis bilis. Likewise an investigation of 242 cats consisting of strays, village, suburban and city cats revealed 79 (33%) animals infected with O. felineus. Higher prevalences were seen in strays and village cats compared to suburban cats. No urban cats, which lived in apartments, were found to be infected. Other important zoonoses included Echinococcus granulosus, detected in 2 of the 51 necropsied village dogs and E. multilocularis was found in 2 out of 124 necropsied stray cats. Investigations of locally caught fish revealed 10 of 107 (9%) roach (Rutilus rutilus), 49 of 68(72%) ide (Leuciscus idus) and 2 of 79 (2.5%) bream (Abramis brama) infested with trematode metacercariae. No metacercariae were found in 609 crucian carp (Carassius carassius), 35 tench (Tinca tinca), 79 carp (Cyprinus carpio), 46 perch (Perca fluviatilis) or 20 zander (Sander lucioperca). PMID:24943190

  2. Health Effects in Fish of Long-Term Exposure to Effluents from Wastewater Treatment Works

    PubMed Central

    Liney, Katherine E.; Hagger, Josephine A.; Tyler, Charles R.; Depledge, Michael H.; Galloway, Tamara S.; Jobling, Susan

    2006-01-01

    Concern has been raised in recent years that exposure to wastewater treatment effluents containing estrogenic chemicals can disrupt the endocrine functioning of riverine fish and cause permanent alterations in the structure and function of the reproductive system. Reproductive disorders may not necessarily arise as a result of estrogenic effects alone, and there is a need for a better understanding of the relative importance of endocrine disruption in relation to other forms of toxicity. Here, the integrated health effects of long-term effluent exposure are reported (reproductive, endocrine, immune, genotoxic, nephrotoxic). Early life-stage roach, Rutilus rutilus, were exposed for 300 days to treated wastewater effluent at concentrations of 0, 15.2, 34.8, and 78.7% (with dechlorinated tap water as diluent). Concentrations of treated effluents that induced feminization of male roach, measured as vitellogenin induction and histological alteration to gonads, also caused statistically significant alterations in kidney development (tubule diameter), modulated immune function (differential cell count, total number of thrombocytes), and caused genotoxic damage (micronucleus induction and single-strand breaks in gill and blood cells). Genotoxic and immunotoxic effects occurred at concentrations of wastewater effluent lower than those required to induce recognizable changes in the structure and function of the reproductive endocrine system. These findings emphasize the need for multiple biological end points in tests that assess the potential health effects of wastewater effluents. They also suggest that for some effluents, genotoxic and immune end points may be more sensitive than estrogenic (endocrine-mediated) end points as indicators of exposure in fish. PMID:16818251

  3. Assessing anthropogenic impact on boreal lakes with historical fish species distribution data and hydrogeochemical modeling.

    PubMed

    Valinia, Salar; Englund, Gran; Moldan, Filip; Futter, Martyn N; Khler, Stephan J; Bishop, Kevin; Flster, Jens

    2014-09-01

    Quantifying the effects of human activity on the natural environment is dependent on credible estimates of reference conditions to define the state of the environment before the onset of adverse human impacts. In Europe, emission controls that aimed at restoring ecological status were based on hindcasts from process-based models or paleolimnological reconstructions. For instance, 1860 is used in Europe as the target for restoration from acidification concerning biological and chemical parameters. A more practical problem is that the historical states of ecosystems and their function cannot be observed directly. Therefore, we (i) compare estimates of acidification based on long-term observations of roach (Rutilus rutilus) populations with hindcast pH from the hydrogeochemical model MAGIC; (ii) discuss policy implications and possible scope for use of long-term archival data for assessing human impacts on the natural environment and (iii) present a novel conceptual model for interpreting the importance of physico-chemical and ecological deviations from reference conditions. Of the 85 lakes studied, 78 were coherently classified by both methods. In 1980, 28 lakes were classified as acidified with the MAGIC model, however, roach was present in 14 of these. In 2010, MAGIC predicted chemical recovery in 50% of the lakes, however roach only recolonized in five lakes after 1990, showing a lag between chemical and biological recovery. Our study is the first study of its kind to use long-term archival biological data in concert with hydrogeochemical modeling for regional assessments of anthropogenic acidification. Based on our results, we show how the conceptual model can be used to understand and prioritize management of physico-chemical and ecological effects of anthropogenic stressors on surface water quality. PMID:24535943

  4. Temperature and Resource Availability May Interactively Affect Over-Wintering Success of Juvenile Fish in a Changing Climate

    PubMed Central

    Brodersen, Jakob; Rodriguez-Gil, Jos Luis; Jnsson, Mikael; Hansson, Lars-Anders; Brnmark, Christer; Nilsson, P. Anders; Nicolle, Alice; Berglund, Olof

    2011-01-01

    The predicted global warming may affect freshwater systems at several organizational levels, from organism to ecosystem. Specifically, in temperate regions, the projected increase of winter temperatures may have important effects on the over-winter biology of a range of organisms and especially for fish and other ectothermic animals. However, temperature effects on organisms may be directed strongly by resource availability. Here, we investigated whether over-winter loss of biomass and lipid content of juvenile roach (Rutilus rutilus) was affected by the physiologically relatively small (2-5C) changes of winter temperatures predicted by the Intergovernmental Panel on Climate Change (IPCC), under both natural and experimental conditions. This was investigated in combination with the effects of food availability. Finally, we explored the potential for a correlation between lake temperature and resource levels for planktivorous fish, i.e., zooplankton biomass, during five consecutive winters in a south Swedish lake. We show that small increases in temperature (+2C) affected fish biomass loss in both presence and absence of food, but negatively and positively respectively. Temperature alone explained only a minor part of the variation when food availability was not taken into account. In contrast to other studies, lipid analyses of experimental fish suggest that critical somatic condition rather than critical lipid content determined starvation induced mortality. Our results illustrate the importance of considering not only changes in temperature when predicting organism response to climate change but also food-web interactions, such as resource availability and predation. However, as exemplified by our finding that zooplankton over-winter biomass in the lake was not related to over-winter temperature, this may not be a straightforward task. PMID:21998627

  5. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France

    PubMed Central

    Certad, Gabriela; Dupouy-Camet, Jean; Gantois, Nausicaa; Hammouma-Ghelboun, Ourida; Pottier, Muriel; Guyot, Karine; Benamrouz, Sadia; Osman, Marwan; Delaire, Baptiste; Creusy, Colette; Viscogliosi, Eric; Aliouat-Denis, Cecile Marie; Follet, Jérôme

    2015-01-01

    Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the observation of edible fillet contamination. PMID:26213992

  6. Environmental chemicals active as human antiandrogens do not activate a stickleback androgen receptor but enhance a feminising effect of oestrogen in roach.

    PubMed

    Lange, Anke; Sebire, Marion; Rostkowski, Pawel; Mizutani, Takeshi; Miyagawa, Shinichi; Iguchi, Taisen; Hill, Elizabeth M; Tyler, Charles R

    2015-11-01

    Sexual disruption is reported in wild fish populations living in freshwaters receiving discharges of wastewater treatment works (WwTW) effluents and is associated primarily with the feminisation of males by exposure to oestrogenic chemicals. Antiandrogens could also contribute to the feminisation of male fish, but there are far less data supporting this hypothesis and almost nothing is known for the effects of oestrogens in combination with antiandrogens in fish. We conducted a series of in vivo exposures in two fish species to investigate the potency on reproductive-relevant endpoints of the antiandrogenic antimicrobials triclosan (TCS), chlorophene (CP) and dichlorophene (DCP) and the resin, abietic acid (AbA), all found widely in WwTW effluents. We also undertook exposures with a mixture of antiandrogens and a mixture of antiandrogens in combination with the oestrogen 17α-ethinyloestradiol (EE2). In stickleback (Gasterosteus aculeatus), DCP showed a tendency to reduce spiggin induction in females androgenised by dihydrotestosterone (DHT), but these findings were not conclusive. In roach (Rutilus rutilus), exposures to DCP (178 days), or a mixture of TCS, CP and AbA (185 days), or to the model antiandrogen flutamide (FL, 178 days) had no effect on gonadal sex ratio or on the development of the reproductive ducts. Exposure to EE2 (1.5ng/L, 185 days) induced feminisation of the ducts in 17% of the males and in the mixture of antiandrogens (TCS, CP, AbA) in combination with EE2, almost all (96%) of the males had a feminised reproductive ducts. In stickleback androgen receptor (ARα and ARβ) transactivation assays, the model antiandrogens, FL and procymidone inhibited 11-ketotestosterone (11-KT) induced receptor activation, but none of the human antiandrogens, TCS, CP, DCP and AbA had an effect. These data indicate that antimicrobial antiandrogens in combination can contribute to the feminisation process in exposed males, but they do not appear to act through the androgen receptor in fish. PMID:26440146

  7. Concentration of selected metals in muscle of various fish species.

    PubMed

    Andreji, Jaroslav; Stránai, Ivan; Massányi, Peter; Valent, Miroslav

    2005-01-01

    The purpose of this study was to assess concentration of selected metals (Fe, Mn, Zn, Cu, Ni, Co, Cr, Pb, Cd, and Hg) in the muscle of four common Slovak fish species (chub--Leuciscus cephalus, barbel--Barbus barbus, roach--Rutilus rutilus, and perch--Perca fluviatilis). Furthermore, correlations among the selected metals and order of metal accumulation in the fish muscle were determined. An electrofishing technique was used for collecting the fish from the Nitra River (Slovakia) in September 2003. Concentrations of selected metals were measured using an atomic absorption spectrophotometer Pye Unicam SP9. The concentrations of metals (mg/kg wet weight basis) ranged as follows: Fe 3.41-15.14; Mn 0.20-0.81; Zn 3.51-15.64; Cu 0.25-0.78; Ni 0.07-0.25; Co 0.05-0.19; Cr 0.11-0.42; Pb 0.20-5.81; Cd 0.06-0.56, and Hg 1.35-6.52. Significant correlations (P < 0.05) between Fe-Cu, Fe-Ni, Fe-Cr, Mn-Ni, Mn-Cr, Mn-Cr, Cu-Ni, and Ni-Cr were observed. The level of lead exceeded the maximum allowable concentration in Slovakia by Codex Alimentarius for safe human consumption (0.2 mg/kg) in the majority of samples (97.2%). Content of Cd (0.23 +/- 0.13 mg/kg wet weight) and Hg (2.85 +/- 1.22 mg/kg wet weight) in the fish muscle exceeded maximum allowed levels in all samples. On average, the order of metal concentrations in the fish muscle was: Fe > Zn > Hg > Pb > Cu > Mn > Cd > Cr > Ni > Co. PMID:15792307

  8. Effects of predation pressure and resource use on morphological divergence in omnivorous prey fish

    PubMed Central

    2013-01-01

    Background Body shape is one of the most variable traits of organisms and responds to a broad array of local selective forces. In freshwater fish, divergent body shapes within single species have been repeatedly observed along the littoral-pelagic axes of lakes, where the structural complexity of near shore habitats provides a more diverse set of resources compared to the open-water zones. It remains poorly understood whether similar resource-driven polymorphism occurs among lakes that vary in structural complexity and predation pressure, and whether this variation is heritable. Here, we analyzed body shape in four populations of omnivorous roach (Rutilus rutilus) inhabiting shallow lakes. We tested the relationship between body shape, gradients of resources, predation pressure, and, in a subset of two lakes, diet composition. We used genome scans of 331 polymorphic AFLP markers to test whether there was a heritable component to the observed morphological diversification. Results Body shape differed among lakes and was significantly correlated to differences in predation pressure. Roach from the lake with highest predation pressure were most divergent from the average body shape of all populations, characterized by a more streamlined body and caudally inserted dorsal fins; features that facilitate predator escape. Surprisingly, diet composition was not associated with morphology. AFLP analysis revealed weak genetic differentiation among lakes and no isolation by distance (IBD). Outlier analysis detected three loci under positive selection with differing frequencies in the four populations. General linear models did not support an association of lake-specific genotypes with morphological variation. Conclusion Body shape was divergent among lakes, suggesting that processes previously reported from within single lakes may also be operating at the scale of whole lakes. We found no evidence for body shape being heritable, although sample size was small in these natural populations. Rather than habitat structure and diet, we conclude that predation had a stronger effect on the prevalence of local morphotypes. A variable morphotype facilitating the efficient uptake of a variety of spatially and temporarily scattered resources seems to be favored in these small aquatic systems. PMID:23802571

  9. An evaluation of LSU rDNA D1-D2 sequences for their use in species identification

    PubMed Central

    Sonnenberg, Rainer; Nolte, Arne W; Tautz, Diethard

    2007-01-01

    Background Identification of species via DNA sequences is the basis for DNA taxonomy and DNA barcoding. Currently there is a strong focus on using a mitochondrial marker for this purpose, in particular a fragment from the cytochrome oxidase I gene (COI). While there is ample evidence that this marker is indeed suitable across a broad taxonomic range to delineate species, it has also become clear that a complementation by a nuclear marker system could be advantageous. Ribosomal RNA genes could be suitable for this purpose, because of their global occurrence and the possibility to design universal primers. However, it has so far been assumed that these genes are too highly conserved to allow resolution at, or even beyond the species level. On the other hand, it is known that ribosomal gene regions harbour also highly divergent parts. We explore here the information content of two adjacent divergence regions of the large subunit ribosomal gene, the D1-D2 region. Results Universal primers were designed to amplify the D1-D2 region from all metazoa. We show that amplification products in the size between 800–1300 bp can be obtained across a broad range of animal taxa, provided some optimizations of the PCR procedure are implemented. Although the ribosomal genes occur in multiple copies in the genomes, we find generally very little intra-individual polymorphism (<< 0.1% on average) indicating that concerted evolution is very effective in most cases. Studies in two fish taxa (genus Cottus and genus Aphyosemion) show that the D1-D2 LSU sequence can resolve even very closely related species with the same fidelity as COI sequences. In one case we can even show that a mitochondrial transfer must have occurred, since the nuclear sequence confirms the taxonomic assignment, while the mitochondrial sequence would have led to the wrong classification. We have further explored whether hybrids between species can be detected with the nuclear sequence and we show for a test case of natural hybrids among cyprinid fish species (Alburnus alburnus and Rutilus rutilus) that this is indeed possible. Conclusion The D1-D2 LSU region is a suitable marker region for applications in DNA based species identification and should be considered to be routinely used as a marker complementing broad scale studies based on mitochondrial markers. PMID:17306026

  10. Molecular characterization of estrogen receptor genes in Gobiocypris rarus and their expression upon endocrine disrupting chemicals exposure in juveniles.

    PubMed

    Wang, Houpeng; Wang, Jingjing; Wu, Tingting; Qin, Fang; Hu, Xiaoqi; Wang, Lihong; Wang, Zaizhao

    2011-01-17

    Estrogens play an important role in many physiological processes of vertebrates, mediated by estrogen receptors (ERs). The full length of the cDNAs for ERα, ERβ1, and ERβ2 were isolated and characterized from Gobiocypris rarus. G. rarus ERs shared the highest amino acid identities with counterparts of three cyprinidae species (Pimephales promelas ERα: 91.1%, Rutilus rutilus ERβ1: 92.9%, Tanichthy albonubes ERβ2: 93.5%). The phylogenic tree of vertebrate ERs indicates G. rarus ER isoforms are more related to counterparts of cyprinidae species. The expression of ERα mRNA was high in gonad and liver. The ERβ1 transcript was the highest in the liver of female fish and was evenly high in the liver, testis and intestine in male. The ERβ2 transcript was high in liver, gonad, and intestine. G. rarus juvenile at 34 days post fertilization were exposed for 3 days to endocrine disrupting chemicals including 17α-ethynylestradiol (EE2), 4-nonylphenol (NP) and bisphenol A (BPA). ER mRNA expression following the xenoestrogens' exposure was analyzed by quantitative real-time PCR. EE2 exposure at 0.01, 0.1 and 1 nM significantly up-regulated ERα transcript. ERβ1 mRNA expression was suppressed by EE2 at all concentrations. However ERβ2 transcript had opposite response to EE2 at low and high concentrations (up-regulation at 0.1 nM, down-regulation at 1 nM). Except a weak increase of ERα at 10 nM EE2, varying decrease of three ER transcripts was resulted in by NP at 10, 100 and 1000 nM. ERα transcript was significantly up-regulated by BPA at 10 nM. A non-significant weak increase in ERβ1 mRNA expression was caused by 1 nM BPA. However 1 nM and 10 nM BPA exposures resulted in significant and non-significant decrease of ERβ2 transcript, respectively. The BPA exposures at other concentrations almost had no effect on the ER transcripts. Vitellogenin (Vtg) mRNA expression profiling following exposure to three xenoestrogens indicated that Vtg transcript is a sensitive biomarker of the juvenile G. rarus at 34 dpf to the EDCs, especially to EE2. These results combined suggest that the ER genes are not modulated in the same manner by EE2, NP, and BPA and that ERs may not contribute equally to the transcriptional regulation of genes involved in fish development and reproduction. PMID:21111493

  11. Comparing two fish sampling standards over time: largely congruent results but with caveats

    USGS Publications Warehouse

    Yule, Daniel L.; Evrard, Lori M.; Cachera, Sébastien; Colon, Michel; Guillard, Jean

    2013-01-01

    1. We sampled Lake Bourget (surface area = 44 km2) using CEN standard gillnet and provisional standard acoustic survey methods over 3 years (2005, 2010 and 2011) as the fish community responded to re-oligotrophication. A total of 16 species were caught in benthic gillnets and three species in pelagic gillnets. 2. Lake Bourget results were consistent with a recent study (Emmrich et al., Freshwater Biology, 57, 2012, 2436) showing strong correspondence between average biomass-per-unit-effort (BPUE) in standard benthic gillnets and average acoustic volume backscattering when smaller lakes (0.25–5.45 km2) were treated as sample units. 3. The BPUE of whitefish (Coregonus lavaretus), perch (Perca fluviatilis) and roach (Rutilus rutilus) measured by benthic gillnets all declined significantly with increasing bathymetric depth; 93% of nets set at depths >50 m caught zero fish. 4. Pelagic gillnetting indicated that small (20 m) increased significantly after 2005. 5. Both surveys showed whitefish biomass increased significantly during the study, but whitefish ≥25 cm were poorly represented in benthic gillnet catches. Contrary to the acoustic findings, the BPUE of perch and roach in benthic gillnets did not vary significantly over time. This metric is insensitive to changes in size structure in that a high catch of small fish and a low catch of large fish in different years can provide similar average BPUE estimates. 6. We examined correlations between BPUE in benthic gillnets and acoustic methods at fine spatial scales by averaging acoustic backscattering measurements encompassed by buffers of varying size (250–2000 m) around individual gillnets and by averaging samples collected from lake quadrants. Correlations at fines scales were generally poor, and only in 1 year was the quadrant correlation significant. The lack of correlation can be explained, in part, by the two gears sampling different components of the fish community. Conversely, in pelagic habitat, where the fish community was simpler, we found BPUE in pelagic nets to be strongly correlated with acoustic backscattering. 7. With respect to large lakes like Lake Bourget, we hypothesise that the congruence in average biomass measurements provided by these two survey methods occurs because these different community components are responding similarly to a common driver like lake trophic status (or possibly multiple drivers operating in synergy).

  12. Predicted Exposures to Steroid Estrogens in U.K. Rivers Correlate with Widespread Sexual Disruption in Wild Fish Populations

    PubMed Central

    Jobling, Susan; Williams, Richard; Johnson, Andrew; Taylor, Ayesha; Gross-Sorokin, Melanie; Nolan, Monique; Tyler, Charles R.; van Aerle, Ronny; Santos, Eduarda; Brighty, Geoff

    2006-01-01

    Steroidal estrogens, originating principally from human excretion, are likely to play a major role in causing widespread endocrine disruption in wild populations of the roach (Rutilus rutilus), a common cyprinid fish, in rivers contaminated by treated sewage effluents. Given the extent of this problem, risk assessment models are needed to predict the location and severity of endocrine disruption in river catchments and to identify areas where regulation of sewage discharges to remove these contaminants is necessary. In this study we attempted to correlate the extent of endocrine disruption in roach in British rivers, with their predicted exposure to steroid estrogens derived from the human population. The predictions of steroid estrogen exposure at each river site were determined by combining the modeled concentrations of the individual steroid estrogens [17β -estradiol (E2), estrone (E1), and 17α -ethinylestradiol (EE2)] in each sewage effluent with their predicted dilution in the immediate receiving water. This model was applied to 45 sites on 39 rivers throughout the United Kingdom. Each site studied was then categorized as either high, medium, or low “risk” on the basis of the assumed additive potency of the three steroid estrogens calculated from data derived from published studies in various cyprinid fish species. We sampled 1,438 wild roach from the predicted high-, medium-, and low-risk river sites and examined them for evidence and severity of endocrine disruption. Both the incidence and the severity of intersex in wild roach were significantly correlated with the predicted concentrations of the natural estrogens (E1 and E2) and the synthetic contraceptive pill estrogen (EE2) present. Predicted steroid estrogen exposure was, however, less well correlated with the plasma vitellogenin concentration measured in the same fish. Moreover, we found no correlation between any of the end points measured in the roach and the proportion of industrial effluents entering the rivers we studied. Overall, our results provide further and substantive evidence to support the hypothesis that steroidal estrogens play a major role in causing intersex in wild freshwater fish in rivers in the United Kingdom and clearly show that the location and severity of these endocrine-disrupting effects can be predicted. PMID:16818244

  13. Oil shale processing as a source of aquatic pollution: monitoring of the biologic effects in caged and feral freshwater fish.

    PubMed Central

    Tuvikene, A; Huuskonen, S; Koponen, K; Ritola, O; Mauer, U; Lindström-Seppä, P

    1999-01-01

    The biologic effects of the oil shale industry on caged rainbow trout (Oncorhynchus mykiss) as well as on feral perch (Perca fluviatilis) and roach (Rutilus rutilus) were studied in the River Narva in northeast Estonia. The River Narva passes the oil shale mining and processing area and thus receives elevated amounts of polycyclic aromatic hydrocarbons (PAHs), heavy metals, and sulfates. The effects of the chemical load were monitored by measuring cytochrome P4501A (CYP1A)-dependent monooxygenase (MO) activities [7-ethoxyresorufin O-deethylase and aryl hydrocarbon hydroxylase (AHH)] as well as conjugation enzyme activities [glutathione S-transferase (GST) and UDP-glucuronosyltransferase] in the liver of fish. CYP1A induction was further studied by detecting the amount and occurrence of the CYP1A protein. Histopathology of tissues (liver, kidney, spleen, and intestine) and the percentage of micronuclei in fish erythrocytes were also determined. Selected PAHs and heavy metals (Cd, Cu, Hg, and Pb) were measured from fish muscle and liver. In spite of the significant accumulation of PAHs, there was no induction of MO activities in any studied fish species. When compared to reference samples, AHH activities were even decreased in feral fish at some of the exposed sites. Detection of CYP1A protein content and the distribution of the CYP1A enzyme by immunohistochemistry also did not show extensive CYP1A induction. Instead, GST activities were significantly increased at exposed sites. Detection of histopathology did not reveal major changes in the morphology of tissues. The micronucleus test also did not show any evidence of genotoxicity. Thus, from the parameters studied, GST activity was most affected. The lack of catalytic CYP1A induction in spite of the heavy loading of PAHs was not studied but has been attributed to the elevated content of other compounds such as heavy metals, some of which can act as inhibitors for MOs. Another possible explanation of this lack of induction is that through adaptation processes the fish could have lost some of their sensitivity to PAHs. Either complex pollution caused by oil shale processing masked part of the harmful effects measured in this study, or oil shale industry did not have any severe effects on fish in the River Narva. Our study illustrates the difficulties in estimating risk in cases where there are numerous various contaminants affecting the biota. Images Figure 1 Figure 2 PMID:10464075

  14. The trace element analysis in freshwater fish species, water and sediment in Iyidere stream (Rize-Turkey).

    PubMed

    Verep, Bulent; Mutlu, Cengiz; Apaydin, Gokhan; Cevik, Ugur

    2012-07-15

    Many environmental problems like dam construction, agricultural debris, flooding and industrial establishments threaten Iyidere stream (Rize, Turkey) on the southeastern coast of the Black Sea (Turkey). The trace element concentrations in water, fish and sediments in lyidere stream (Rize, Turkey) were investigated in this study. The concentration of six different elements in ten freshwater fish species and sediment was determined using energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied for the elemental analysis of fish and sediments. Water samples for trace metals were analyzed using standard spectrophotometry methods. A qualitative analysis of spectral peaks showed that ten different freshwater fish samples (Chondrostoma colchicum, Chalcalburnus chalcoides, Salmo trutta labrax, Alburnoides bipunctatus, Leuciscus cephalus, Barbus taurus escherichia, Capoeta tinca, Neogobius kessleri, Rutilus frisii, Lampetra lanceolata) and sediment contained phosphorus (P), sulphur (S), chlorine (Cl), potassium (K), calcium (Ca) and titanium (Ti). Heavy metals as toxic elements for biota (Pb, Cd, Hg, Zn and Mn etc.) were not detected in fish, water and sediments. Thus, It can be declared that freshwater fish of Iyidere does not contains health risks for consumers in terms of metal pollution. PMID:24171246

  15. Vector and host relationships of California serogroup viruses in western Siberia.

    PubMed

    Mitchell, C J; Lvov, S D; Savage, H M; Calisher, C H; Smith, G C; Lvov, D K; Gubler, D J

    1993-07-01

    During 1990 and 1991, adult mosquitoes were collected along the Ob River and its tributaries in western Siberia from approximately 51 degrees 18'N to 66 degrees 4'N. Fifteen virus strains were isolated from 74,196 mosquitoes tested in 1,874 pools. These included Tahyna virus from Aedes cataphylla-punctor subgroup (one) and Ae. excrucians (one), and Inkoo (INK) virus from Ae. communis (one), Ae. communis subgroup (one), Ae. hexodontus (two), Ae. punctor subgroup (two), Ae. punctor complex (one), and unidentified Aedes species (three). In addition, a single Ae. euedes yielded a strain of snowshoe hare (SSH) virus and a strain of Getah, an alphavirus. A Bunyamwera serogroup virus was isolated from Ae. excrucians. With the exception of the two isolates from a single mosquito, minimum infection rates among mosquito taxa ranged from 0.4 to 16.7 per 1,000. The INK virus isolates were widely distributed geographically; however, seven of the 10 isolates were from two sites north of the Arctic Circle. During 1991, sera from two mouse species, five vole species, and four shrew species were collected along the upper Ob River for serologic tests. The prevalence of neutralizing antibody to SSH virus in these sera was 80%. Prevalence rates in the four most abundant species were Apodemus agrarius, 73%; Clethrionomys rutilus, 71%; Microtus arvalis, 80%; and Sorex araneus, 91%. This is the first attempt to clarify the vector and vertebrate host relationships of California serogroup viruses in western Siberia. PMID:8352392

  16. Beyond the Mediterranean peninsulas: evidence of central European glacial refugia for a temperate forest mammal species, the bank vole (Clethrionomys glareolus).

    PubMed

    Deffontaine, V; Libois, R; Kotlík, P; Sommer, R; Nieberding, C; Paradis, E; Searle, J B; Michaux, J R

    2005-05-01

    This study details the phylogeographic pattern of the bank vole, Clethrionomys glareolus, a European rodent species strongly associated with forest habitat. We used sequences of 1011 base pairs of the mitochondrial DNA cytochrome b gene from 207 bank voles collected in 62 localities spread throughout its distribution area. Our results reveal the presence of three Mediterranean (Spanish, Italian and Balkan) and three continental (western, eastern and 'Ural') phylogroups. The endemic Mediterranean phylogroups did not contribute to the post-glacial recolonization of much of the Palaearctic range of species. Instead, the major part of this region was apparently recolonized by bank voles that survived in glacial refugia in central Europe. Moreover, our phylogeographic analyses also reveal differentiated populations of bank voles in the Ural mountains and elsewhere, which carry the mitochondrial DNA of another related vole species, the ruddy vole (Clethrionomys rutilus). In conclusion, this study demonstrates a complex phylogeographic history for a forest species in Europe which is sufficiently adaptable that, facing climate change, survives in relict southern and northern habitats. The high level of genetic diversity characterizing vole populations from parts of central Europe also highlights the importance of such regions as a source of intraspecific genetic biodiversity. PMID:15836645

  17. Nephropathia epidemica in Norway: antigen and antibodies in rodent reservoirs and antibodies in selected human populations.

    PubMed Central

    Traavik, T.; Sommer, A. I.; Mehl, R.; Berdal, B. P.; Stavem, K.; Hunderi, O. H.; Dalrymple, J. M.

    1984-01-01

    Nephropathia epidemica (NE) antigen was detected by IFAT (indirect fluorescent antibody technique) in the lungs of 14 of 97 bank voles (Clethrionomys glareolus) collected in three endemic areas. The distribution of antigen positive voles within an endemic location was scattered. Antibodies to Korean hemorrhagic fever (KHF) virus antigens were detected by IFAT in 12 of 14 NE antigen positive bank voles and in 15 of 83 that were antigen negative. NE antigen positive voles exhibited higher antibody titres. Antibodies to KHF were demonstrated in sera from C. rutilus and C. rufocanus collected more than 200 km north of the distribution area for C. glareolus. It appears likely that these vole species can serve as virus vectors for NE cases occurring north of the bank vole area. NE antibodies cross-reacting with KHF virus seem to diminish with time after infection in some NE patients, while for others such cross-reacting antibodies were detected up to 12 years after the disease. Antibodies to KHF were detected in eight of 106 healthy forestry workers with no clinical history of NE. No serological cross-reactions were detected between NE/KHF antigens and representative Bunyaviridae present in Norway. NE/KHF-like viruses appear widespread in Norway, both within and outside of the distribution area of the bank vole. PMID:6146649

  18. Implications of climate change for the fishes of the British Isles.

    PubMed

    Graham, C T; Harrod, C

    2009-04-01

    Recent climatic change has been recorded across the globe. Although environmental change is a characteristic feature of life on Earth and has played a major role in the evolution and global distribution of biodiversity, predicted future rates of climatic change, especially in temperature, are such that they will exceed any that has occurred over recent geological time. Climate change is considered as a key threat to biodiversity and to the structure and function of ecosystems that may already be subject to significant anthropogenic stress. The current understanding of climate change and its likely consequences for the fishes of Britain and Ireland and the surrounding seas are reviewed through a series of case studies detailing the likely response of several marine, diadromous and freshwater fishes to climate change. Changes in climate, and in particular, temperature have and will continue to affect fish at all levels of biological organization: cellular, individual, population, species, community and ecosystem, influencing physiological and ecological processes in a number of direct, indirect and complex ways. The response of fishes and of other aquatic taxa will vary according to their tolerances and life stage and are complex and difficult to predict. Fishes may respond directly to climate-change-related shifts in environmental processes or indirectly to other influences, such as community-level interactions with other taxa. However, the ability to adapt to the predicted changes in climate will vary between species and between habitats and there will be winners and losers. In marine habitats, recent changes in fish community structure will continue as fishes shift their distributions relative to their temperature preferences. This may lead to the loss of some economically important cold-adapted species such as Gadus morhua and Clupea harengus from some areas around Britain and Ireland, and the establishment of some new, warm-adapted species. Increased temperatures are likely to favour cool-adapted (e.g. Perca fluviatilis) and warm-adapted freshwater fishes (e.g. roach Rutilus rutilus and other cyprinids) whose distribution and reproductive success may currently be constrained by temperature rather than by cold-adapted species (e.g. salmonids). Species that occur in Britain and Ireland that are at the edge of their distribution will be most affected, both negatively and positively. Populations of conservation importance (e.g.Salvelinus alpinus and Coregonus spp.) may decline irreversibly. However, changes in food-web dynamics and physiological adaptation, for example because of climate change, may obscure or alter predicted responses. The residual inertia in climate systems is such that even a complete cessation in emissions would still leave fishes exposed to continued climate change for at least half a century. Hence, regardless of the success or failure of programmes aimed at curbing climate change, major changes in fish communities can be expected over the next 50 years with a concomitant need to adapt management strategies accordingly. PMID:20735625

  19. Gas-liquid chromatography-tandem mass spectrometry methodology for the quantitation of estrogenic contaminants in bile of fish exposed to wastewater treatment works effluents and from wild populations.

    PubMed

    Fenlon, Kate A; Johnson, Andrew C; Tyler, Charles R; Hill, Elizabeth M

    2010-01-01

    Fish can be exposed to a complex mixture of chemical contaminants arising from the exposure to wastewater treatment works (WwTWs) effluents. Some of these contaminants are estrogenic and have been associated with feminisation of male fish and the presence of populations containing intersex individuals. However the detection of trace levels (ng/L) of estrogenic chemicals surface waters can be difficult and does not give information on the exposure of aquatic organisms to these contaminants. In this study we assessed whether the analysis of estrogenic substances that bioconcentrate in fish bile can be used to detect the exposure of fish to feminising contaminants in receiving waters and effluents, and thus facilitate their monitoring of these substances in aquatic environments. Estrogenic metabolites in bile were deconjugated using enzymatic hydrolysis and partially purified by solid phase extraction. Steroidal and xenoestrogens were derivatized to their trimethylsilyl ethers and quantified by gas-liquid chromatography-mass spectrometry (GC-MS/MS) using multiple reaction monitoring. The method was validated using spiked bile samples from immature female rainbow trout (Oncorhynchus mykiss) as well as bile from sexually mature roach (Rutilus rutilus) that had been exposed to either tap water or an undiluted estrogenic effluent for 10 days or captured from a river site downstream of a WwTWs effluent discharge. The mean recovery of target analytes from spiked bile was between 86 and 99% and the limit of detection was between 0.1 and 0.7ng/mL bile for bisphenol A (BPA), 17beta-estradiol (E2), estrone (E1) and 17alpha-ethinylestradiol (EE2), and 11, 60 and 327ng/mL bile for branched nonyl chain isomeric mixtures of 4-nonylphenolethoxylate (NP1EO), 4-nonylphenol (NP) and 4-nonylphenoldiethoxylate (NP2EO), respectively. All target analytes were detected in bile from roach exposed directly to a WwTWs effluent, with concentrations between 6-13microg/mL bile for NP, 18-21microg/mL for NP1EO, 75-135microg/mL for NP2EO, 0.7-2.5microg/mL for BPA, E2 and E1 and 17-29ng/mL for EE2. With the exception of NP2EO, all analytes were detected in at least 2 out of the 5 fish sampled from the River Thames. BPA and NP1EO were detected in all three reference fish held in tap water indicating possible contamination from laboratory plastics. The work shows that analysis of 20-100microL quantities of bile could be a useful approach in detecting exposure to mixtures of estrogenic contaminants taken up by fish from WwTW effluents and has the potential for monitoring the efficacy of remediation strategies that may be adopted for reduction of these endocrine disrupting chemicals in the aquatic environment. PMID:19932485

  20. [Developmental instability of the organism as a result of pessimization of environment under anthropogenic transformation of natural landscapes].

    PubMed

    Shadrina, E G; Vol'pert, Ia L

    2014-01-01

    The value of fluctuating asymmetry is considered to be an indicator of the developmental instability of the organism. The consequences of activities of the mining industry plants, which are characterized by alienation and transformation of large areas of natural landscapes, are analyzed as an anthropogenic factor. The objects of study were small mammals (northern red-backed (Clethrionomys rutilus) and gray red-backed (Clethrionomys rufocanus) voles, tundra vole (Microtus oeconomus), Laxmann's (Sorex caecutiens) and tundra (S. tundrensis) shrews) and trees (Japanese white birch (Betula platyphylla), Betula divaricate, Betula exilis, Duschekiafruticosa, and common osier (Salix viminalis)). In total, 3500 skulls and approximately 30000 leaves collected in the taiga zone of Yakutia were studied. The index offluctuating asymmetry, as well as population parameters and composition of small mammal communities, were analyzed. The data on the value of the fluctuating asymmetry in the studied species in natural habitats are given. It is shown that, in natural conditions, this parameter can rise with deterioration in living conditions, particularly at the ecological periphery of the range. Anthropogenic transformation of natural landscapes creates an "anthropogenic periphery" and causes changes similar to the adaptive responses at the northern limit of the distribution of species. It was found that, through pollution and disruption of ecosystems, the mining industry affects all levels of organization of the living matter, but the population and cenotic parameters give an unambiguous response only at macroanthropogenic transformations. Increase in the level of fluctuating asymmetry is the most sensitive indicator of anthropogenic impact and it should also be taken into account that disruptions in the developmental stability of an organism reflect the destructive processes occurring in the population and community. PMID:25720274

  1. Population dynamics of red-backed voles (Myodes) in North America.

    PubMed

    Boonstra, Rudy; Krebs, Charles J

    2012-03-01

    We review the population dynamics of red-backed voles (Myodes species) in North America, the main deciduous and coniferous forest-dwelling microtines on this continent, and compare and contrast their pattern with that of the same or similar species in Eurasia. We identify 7 long-term studies of population changes in Myodes in North America. Using autoregressive and spectral analysis, we found that only 2 of the 7 show 3- to 5-year cycles like those found in some Eurasian populations. There was no relationship between latitude and cycling. The general lack of cyclicity is associated with two key aspects of their demography that act in tandem: first, poor overwinter survival in most years; second, chronically low densities, with irregular outbreak years. Eight factors might explain why some Myodes populations fluctuate in cycles and others fluctuate irregularly, and we review the evidence for each factor: food supplies, nutrients, predation, interspecific competition, disease, weather, spacing behavior and interactive effects. Of these eight, only food supplies appear to be sufficient to explain the differences between cyclic and non-cyclic populations. Irregular fluctuations are the result of pulsed food supplies in the form of berry crops (M. rutilus) or tree seeds (M. gapperi) linked to weather patterns. We argue that, to understand the cause for the patterns in the respective hemispheres, we must know the mechanism(s) driving population change and this must be linked to rigorous field tests. We suggest that a large-scale, year-round feeding experiment should improve overwintering survival, increase standing densities, and flip non-cyclic Myodes populations into cyclic dynamics that would mimic the patterns seen in the cyclic populations found in parts of Eurasia. PMID:21947547

  2. Tracing the colonization history of the Indian Ocean scops-owls (Strigiformes: Otus) with further insight into the spatio-temporal origin of the Malagasy avifauna

    PubMed Central

    2008-01-01

    Background The island of Madagascar and surrounding volcanic and coralline islands are considered to form a biodiversity hotspot with large numbers of unique taxa. The origin of this endemic fauna can be explained by two different factors: vicariance or over-water-dispersal. Deciphering which factor explains the current distributional pattern of a given taxonomic group requires robust phylogenies as well as estimates of divergence times. The lineage of Indian Ocean scops-owls (Otus: Strigidae) includes six or seven species that are endemic to Madagascar and portions of the Comoros and Seychelles archipelagos; little is known about the species limits, biogeographic affinities and relationships to each other. In the present study, using DNA sequence data gathered from six loci, we examine the biogeographic history of the Indian Ocean scops-owls. We also compare the pattern and timing of colonization of the Indian Ocean islands by scops-owls with divergence times already proposed for other bird taxa. Results Our analyses revealed that Indian Ocean islands scops-owls do not form a monophyletic assemblage: the Seychelles Otus insularis is genetically closer to the South-East Asian endemic O. sunia than to species from the Comoros and Madagascar. The Pemba Scops-owls O. pembaensis, often considered closely related to, if not conspecific with O. rutilus of Madagascar, is instead closely related to the African mainland O. senegalensis. Relationships among the Indian Ocean taxa from the Comoros and Madagascar are unresolved, despite the analysis of over 4000 bp, suggesting a diversification burst after the initial colonization event. We also highlight one case of putative back-colonization to the Asian mainland from an island ancestor (O. sunia). Our divergence date estimates, using a Bayesian relaxed clock method, suggest that all these events occurred during the last 3.6 myr; albeit colonization of the Indian Ocean islands were not synchronous, O. pembaensis diverged from O. senegalensis about 1.7 mya while species from Madagascar and the Comoro diverged from their continental sister-group about 3.6 mya. We highlight that our estimates coincide with estimates of diversification from other bird lineages. Conclusion Our analyses revealed the occurrence of multiple synchronous colonization events of the Indian Ocean islands by scops-owls, at a time when faunistic exchanges involving Madagascar was common as a result of lowered sea-level that would have allowed the formation of stepping-stone islands. Patterns of diversification that emerged from the scops-owls data are: 1) a star-like pattern concerning the order of colonization of the Indian Ocean islands and 2) the high genetic distinctiveness among all Indian Ocean taxa, reinforcing their recognition as distinct species. PMID:18611281

  3. Molecular characterization and specific detection of Anaplasma species (AP-sd) in sika deer and its first detection in wild brown bears and rodents in Hokkaido, Japan.

    PubMed

    Moustafa, Mohamed Abdallah Mohamed; Lee, Kyunglee; Taylor, Kyle; Nakao, Ryo; Sashika, Mariko; Shimozuru, Michito; Tsubota, Toshio

    2015-12-01

    A previously undescribed Anaplasma species (herein referred to as AP-sd) has been detected in sika deer, cattle and ticks in Japan. Despite being highly similar to some strains of A. phagocytophilum, AP-sd has never been detected in humans. Its ambiguous epidemiology and the lack of tools for its specific detection make it difficult to understand and interpret the prevalence of this Anaplasma species. We developed a method for specific detection, and examined AP-sd prevalence in Hokkaido wildlife. Our study included 250 sika deer (Cervus nippon yesoensis), 13 brown bears (Ursus arctos yesoensis) and 252 rodents including 138 (Apodemus speciosus), 45 (Apodemus argenteus), 42 (Myodes rufocanus) and 27 (Myodes rutilus) were collected from Hokkaido island, northern Japan, collected during 2010 to 2015. A 770 bp and 382 bp segment of the 16S rRNA and gltA genes, respectively, were amplified by nested PCR. Results were confirmed by cloning and sequencing of the positive PCR products. A reverse line blot hybridization (RLB) based on the 16S rRNA gene was then developed for the specific detection of AP-sd. The prevalence of AP-sd by nested PCR in sika deer was 51% (128/250). We detected this Anaplasma sp. for the first time in wild brown bears and rodents with a prevalence of 15% (2/13) and 2.4% (6/252), respectively. The sequencing results of the 16S rRNA and gltA gene amplicons were divergent from the selected A. phagocytophilum sequences in GenBank. Using a newly designed AP-sd specific probe for RLB has enabled us to specifically detect this Anaplasma species. Besides sika deer and cattle, wild brown bears and rodents were identified as potential reservoir hosts for AP-sd. This study provided a high throughput molecular method that specifically detects AP-sd, and which can be used to investigate its ecology and its potential as a threat to humans in Japan. PMID:26431688

  4. Attracted to the enemy: Aedes aegypti prefers oviposition sites with predator-killed conspecifics

    PubMed Central

    Albeny-Simoes, Daniel; Murrell, Ebony G.; Elliot, Simon L.; Andrade, Mateus R.; Lima, Eraldo; Juliano, Steven A.; Vilela, Evaldo F.

    2014-01-01

    Oviposition habitat choices of species with aquatic larvae is expected to be influenced by both offspring risk of mortality due to predation, and offspring growth potential. Aquatic predators may indirectly influence growth potential for prey by reducing prey density and, for filter feeding prey, by increasing bacterial food for prey via added organic matter (feces, partially eaten victims), creating the potential for interactive effects on oviposition choices. We tested the hypothesis that the mosquito Aedes aegypti preferentially oviposit in habitats with predatory Toxorhynchites larvae because of indirect effects of predation on chemical cues indicating bacterial abundance. We predicted that A. aegypti would avoid oviposition in sites with Toxorhynchites, but prefer to oviposit where bacterial food for larvae is abundant, and that predation by Toxorhynchites would increase bacterial abundances. Gravid A. aegypti were offered paired oviposition sites representing choices among: predator presence; the act of predation; conspecific density; dead conspecific larvae; and bacterial activity. Aedes aegypti preferentially oviposited in sites with T. theobaldi predation, and with killed conspecific larvae, but failed to detect preferences for other treatments. The antibiotic Tetracycline eliminated the strongest oviposition preference. Both predation by Toxorhynchites and killed larvae increased bacterial abundances, suggesting that oviposition attraction is cued by bacteria. Our results show the potential for indirect effects, like trophic cascades, to influence oviposition choices and community composition in aquatic systems. Our results suggest that predators like Toxorhynchites may be doubly beneficial as biocontrol agents because of the attraction of ovipositing mosquitoes to bacterial by-products of Toxorhynchites feeding. PMID:24590205

  5. Mosquito Faunal Survey In a Central Park of the City of São Paulo, Brazil.

    PubMed

    Ceretti-Júnior, Walter; Medeiros-Sousa, Antônio Ralph; Bruno Wilke, André Barretto; Strobel, Regina Claudia; Dias Orico, Lilian; Souza Teixeira, Renildo; Marques, Sandro; Toledo Marrelli, Mauro

    2015-06-01

    A total of 2,582 specimens of mosquitoes of 16 taxonomic categories grouped into 5 genera (Aedes, Culex, Mansonia, Toxorhynchites, and Wyeomyia) were collected in a central park of São Paulo City, Brazil. It is crucial to include such an area in official entomological surveillance programs since this park has all the epidemiological characteristics needed to maintain an enzootic cycle of arboviruses. PMID:26181694

  6. Mosquito fauna and breeding habitats of anophelines in Little Andaman Island, Andaman and Nicobar Islands, India.

    PubMed

    Das, M K; Nagpal, B N; Ansari, M A

    2002-01-01

    A total of 37 species of mosquitoes belonging to nine genera--Anopheles, Aedes, Armigeres, Culex, Harpagomyia, Mansonia, Orthopodomyia, Toxorhynchites and Uranotaenia were collected from Little Andaman Island. Mosquitoes of nine Anopheles group of species--An. barbirostris, An. barbumbrosus, An. balabacensis, An. insulaeflorum, An. kochi, An. philippinensis, An. roperi, An. sundaicus and An. vagus were recorded. An. philippinensis was found to be the most predominant species. Species-specific breeding preference and association in various types of acquatic habitats have been reported. This is the first record of mosquito fauna of Little Andaman Island. PMID:14686116

  7. Biological control of mosquitoes in scrap tires in Brownsville, Texas, USA and Matamoros, Tamaulipas, Mexico.

    PubMed

    Uejio, Christopher K; Hayden, Mary H; Zielinski-Gutierrez, Emily; Lopez, Jose Luis Robles; Barrera, Roberto; Amador, Manuel; Thompson, Gregory; Waterman, Stephen H

    2014-06-01

    Dengue periodically circulates in southern Texas and neighboring Tamaulipas, Mexico; thus, a closer examination of human and vector ecology at the northern limits of North American transmission may improve prevention activities. Scrap tires produce large mosquito populations and increase the risk of dengue transmission. Some households choose not to pay tire disposal fees, and many tires are illegally dumped in residential areas. Biological control may provide low-cost and environmentally friendly mosquito control. This pilot study evaluated the ability of Mesocyclops longisetus to reduce mosquito populations in existing residential scrap tire piles. Mosquito populations were measured by the number of all mosquito pupae within tires or adult Aedes aegypti and Ae. albopictus near piles. Mesocyclops longisetus treated piles did not significantly reduce total mosquito pupae (P = 0.07) in Matamoros, Mexico. The study also evaluated the efficacy of native Toxorhynchites moctezuma which preferentially colonized tire piles under vegetation cover in Brownsville, TX. Toxorhynchites moctezuma larvae significantly reduced total mosquito pupae, but the strength of control diminished over time. PMID:25102598

  8. Epidemiology of tree-hole breeding mosquitoes in the tropical rainforest of Imo State, south-east Nigeria.

    PubMed

    Anosike, Jude C; Nwoke, Bertram E B; Okere, Anthony N; Oku, Ene E; Asor, Joe E; Emmy-Egbe, Ifeyinwa O; Adimike, Desmond A

    2007-01-01

    The study of tree-hole breeding mosquitoes was carried out in the tropical rainforest of Imo State Nigeria (two rural areas and two forest reserves in some parts of Orlu Senatorial Zone) between May-October 2002. Using standard entomological procedures, two macrohabitats (natural tree-holes and bamboo traps) and two microhabitats (leaf axils of cocoyams/pineapples and leaf axils of plantain/banana) were sampled for various mosquito species. Mosquitoes were recovered from all the various biotypes sampled. Types of mosquitoes species encountered, their relative abundance, as well as genera varied significantly during the study (p<0.05). Four genera of mosquitoes: Aedes, Culex, Anopheles and Toxorhynchites were recovered while 16 species of mosquitoes encountered include: Aedes aegypti, Ae. africanus, Ae. simpsoni, Ae. albopictus, Ae. stokesi, Ae. taylori, Ae. apicoargenteus, Culex quinquefasciatus, Cx. nebulosus, Cx. trigripes, Cx. decens, Anopheles gambiae, An. funiestus, An. coustani and Toxorhynchites viridibasis. Most of the mosquitoes showed oviposition preferences for one or more habitats. The presence of Ae. africanus, Ae. simpsoni and Ae. aegypti indicate that the study areas were at risk of yellow fever epidemic. The presence of Anopheles and Culex species ensured endemicity of malaria and filariasis, while the recovery of Ae. albopictus in this region suggests a possible outbreak of dengue fever in future if not properly controlled. PMID:17655174

  9. Modelling the Active Hearing Process in Mosquitoes

    NASA Astrophysics Data System (ADS)

    Avitabile, Daniele; Homer, Martin; Jackson, Joe; Robert, Daniel; Champneys, Alan

    2011-11-01

    A simple microscopic mechanistic model is described of the active amplification within the Johnston's organ of the mosquito species Toxorhynchites brevipalpis. The model is based on the description of the antenna as a forced-damped oscillator coupled to a set of active threads (ensembles of scolopidia) that provide an impulsive force when they twitch. This twitching is in turn controlled by channels that are opened and closed if the antennal oscillation reaches a critical amplitude. The model matches both qualitatively and quantitatively with recent experiments. New results are presented using mathematical homogenization techniques to derive a mesoscopic model as a simple oscillator with nonlinear force and damping characteristics. It is shown how the results from this new model closely resemble those from the microscopic model as the number of threads approach physiologically correct values.

  10. PHYLOGENETIC ANALYSIS REVEALS GENETIC VARIATIONS OF DENSOVIRUS ISOLATED FROM FIELD MOSQUITOES IN BANGKOK AND SURROUNDING REGIONS.

    PubMed

    Boonnak, Kobporn; Suttitheptumrong, Aroonroong; Jotekratok, Ubonwan; Pattanakitsakul, Sa-Nga

    2015-03-01

    Screening for densoviruses (DNVs) from Aedes, Culex and Toxorhynchites mosquitoes collected in Bangkok and surrounding regions identified two clades of Aedes DNV; Ae. aegypti DNV (AaeDNV) and Ae. albopictus DNV (AalDNV) by PCR-restriction fragment length polymorphism (PCR-RFLP). From nucleotide sequencing and phylogenetic analysis of PCR amplicons of a fragment of DNV capsid gene, these DNVs were shown to be new DNV genetic variations similar to AaeDNV. Isolation and identification of densoviruses from indigenous field mosquitoes reside in natural habitat should be helpful in monitoring the distribution of DNVs in important mosquitoes, especially Ae. aegypti and Ae. albopictus, vector for dengue and yellow fever viruses. PMID:26513923

  11. Radiosensitivity of cultured insect cells: II. Diptera

    SciTech Connect

    Koval, T.M.

    1983-10-01

    The radiosensitivity of five dipteran cell lines representing three mosquito genera and one fruit fly genus were examined. These lines are: (1) ATC-10, Aedes aegypti; (2) RU-TAE-14, Toxorhynchites amboinensis; (3) RU-ASE-2A, Anopheles stephensi; (4) WR69-DM-1, Drosophila melanogaster; and (5) WR69-DM-2, Drosophila melanogaster. Population doubling times for these lines range from approximately 16 to 48 hr. Diploid chromosome numbers are six for the mosquito cells and eight for the fruit fly cells D/sub 0/ values are 5.1 and 6.5 Gy for the Drosophila cell lines and 3.6, 6.2, and 10.2 Gy for the mosquito cell lines. The results of this study demonstrate that dipteran insect cells are a few times more resistant to radiation than mammalian cells, but not nearly as radioresistant as lepidopteran cells.

  12. Mosquitoes of the mangrove forests of India: part 5--Chorao, Goa, and Vikhroli, Maharashtra.

    PubMed

    Rajavel, A R; Natarajan, R; Vaidyanathan, K; Soniya, V P

    2007-06-01

    Mosquitoes of 14 species belonging to 9 subgenera and 9 genera were recorded in Chorao mangroves of Goa, and 12 species belonging to 9 subgenera and 7 genera in the mangroves of Vikhroli, Maharashtra, in India. Genera recorded were Aedes, Anopheles, Armigeres, Culex, Mansonia, Ochlerotatus, Orthopodomyia, Toxorhynchites, Uranotaenia, and Verrallina. Species common to both the mangroves were Ae. albopictus, Ae. novalbopictus, An. subpictus, Cx. sitiens, Oc. wardi, Ur. atra, and Ve. lugubris. Tree holes, crab holes, and swamp pools were the common larval habitats in Chorao, but tree holes were absent in Vikhroli. Adults of Ae. albopictus, Ae. novalbopictus, Ar. subalbatus, Cx. gelidus Cx. sitiens, Ma. indiana, Ur. atra, and Ve. lugubris were found landing on humans. Aedes novalbopictus, Oc. wardi, and Or. anopheloides are new records for the state of Goa. PMID:17847838

  13. Dengue type 1 epidemic with haemorrhagic manifestations in Fiji, 1989-90.

    PubMed Central

    Fagbami, A. H.; Mataika, J. U.; Shrestha, M.; Gubler, D. J.

    1995-01-01

    A dengue type 1 epidemic occurred in Fiji between July 1989 and July 1990. Virus isolation in C6/36 cell cultures and Toxorhynchites mosquitos yielded 36 strains. Of the 3686 cases recorded by the Ministry of Health, 60% involved indigenous Fijians and 37%, Indians. A house-to-house survey revealed that a large majority of patients had classical dengue symptoms and 8% reported haemorrhagic manifestations. Among the children and adults hospitalized for dengue, 43% had haemorrhagic manifestations, including epistaxis, gingival bleeding, haematemesis, melaena and haematuria. A total of 15 patients with haemorrhagic manifestations and/or shock died, 10 of whom were aged 0-15 years; the diagnoses were confirmed in four cases by virus isolation or serology. PMID:7614660

  14. Species Composition and Ecological Aspects of Immature Mosquitoes (Diptera: Culicidae) in Bromeliads in Urban Parks in the City of São Paulo, Brazil

    PubMed Central

    Ceretti-Junior, Walter; de Oliveira Christe, Rafael; Rizzo, Marco; Strobel, Regina Claudia; de Matos Junior, Marco Otavio; de Mello, Maria Helena Silva Homem; Fernandes, Aristides; Medeiros-Sousa, Antônio Ralph; de Carvalho, Gabriela Cristina; Marrelli, Mauro Toledo

    2016-01-01

    Background: Bromeliads can be epiphytic, terrestrial or saxicolous and use strategies to allow water to be retained in their leaf axils, where various arthropods can be found. These include mosquitoes, whose larvae are the most abundant and commonly found organisms in the leaf axils. The objective of this study was to look for immature forms of mosquitoes (the larval and pupal stages) in bromeliads in municipal parks in São Paulo and to discuss the ecological and epidemiological importance of these insects. Methods: From October 2010 to July 2013, immature mosquitoes were collected from bromeliads in 65 municipal parks in the city of São Paulo, Brazil, using suction samplers. The immature forms were maintained until adult forms emerged, and these were then identified morphologically. Results: Two thousand forty-two immature-stage specimens belonging to the genera Aedes, Culex, Trichoprosopon, Toxorhynchites, Limatus and Wyeomyia were found in bromeliads in 15 of the 65 parks visited. Aedes albopictus was the most abundant species (660 specimens collected), followed by Culex quinquefasciatus (548 specimens) and Cx. (Microculex) imitator (444). The taxa with the most widespread distribution were Ae. aegypti and Toxorhynchites spp, followed by Ae. albopictus and Cx. quinquefasciatus. Conclusion: Bromeliads in urban parks are refuges for populations of native species of Culicidae and breeding sites for exotic species that are generally of epidemiological interest. Hence, administrators and surveillance and mosquito-control agencies must constantly monitor these microenvironments as the presence of these species endangers the health of park users and employees as well as people living near the parks. PMID:27047978

  15. Overwintering strategies of mosquitoes (Diptera:Culicidae) on warmer islands may predict impact of global warming on Kyushu, Japan.

    PubMed

    Mogi, M

    1996-05-01

    Mosquito overwintering was studied on Tanegashima and Yakushima, islands south of Kyushu, to predict the impact of global warming on northern Kyushu where mosquitoes overwinter in diapause. On Tanegashima and Yakushima, the following 5 types of overwintering strategies were recognized: (1) continued reproduction without diapause (2 Anopheles spp., 2 Culex spp., 2 Aedes spp.); (2) diapausing female adults but a few adults from late-developing larvae may emerge in midwinter (2 Anopheles spp. and 9 culex spp.); (3) diapausing eggs but a few adults may emerge in midwinter (5 Aedes spp.); (4) diapausing larvae (1 Orthopodomyia sp., 1 Aedes sp., 1 Armigeres sp., 1 Uranotaenia sp., 1 Toxorhynchites sp.); and (5) diapausing eggs and larvae (1 Tripteroides sp.). Few females of 4 aedine species were collected while seeking hosts in midwinter, but neither larvae nor adults of Culex tritaeniorhynchus Giles or southern house mosquito, Culex quinquefasciatus Say, were found during this survey. The 5 degrees C increase in the midwinter mean temperature in northern Kyushu probably will not produce serious mosquito problems directly, but the proximity of the subtropical regions may have significant effects through dispersal of adult mosquitoes. PMID:8667392

  16. Mosquito community structure in phytotelmata from a South American temperate wetland.

    PubMed

    Albicócco, Andrea Paola; Carbajo, Aníbal Eduardo; Vezzani, Darío

    2011-12-01

    Phytotelmata, or plant-held waters, are considered to be good model systems for the study of community ecology. The fauna of these natural container habitats, particularly the mosquitoes, have been extensively investigated in tropical regions, but there is little known about them in temperate South America. We assessed the structure of immature mosquito communities in leaf axils, tree holes, and bamboo stumps from a temperate wetland of Argentina. A total of 4,330 immature mosquitoes were collected among the 2,606 phytotelmata inspected. Leaf axils of eight plant species and tree holes were larval habitats for nine mosquito species belonging to the genus Culex, Wyeomyia, Isostomyia, and Toxorhynchites. The mosquito communities showed richness ranging from one to four species. Marked differences were detected in the plant specificity for the species collected. Some of them were exclusively found in one plant species (Isostomyia paranensis in Scirpus giganteus), whereas others were collected in up to five plant species but belonging to the same phytotelm class, the leaf axils. Those from tree holes are well-known dwellers of artificial containers and ground water habitats, such as Culex pipiens. Our results support the idea of low mosquito richness in phytotelmata from temperate regions in comparison with tropical areas, but the observed specificity patterns echo the findings of tropical forests. PMID:22129416

  17. UNIVERSAL PRIMERS FOR THE AMPLIFICATION AND SEQUENCE ANALYSIS OF ACTIN-1 FROM DIVERSE MOSQUITO SPECIES

    PubMed Central

    STALEY, MOLLY; DORMAN, KARIN S.; BARTHOLOMAY, LYRIC C.; FERNÁNDEZ-SALAS, ILDEFONSO; FARFAN-ALE, JOSE A.; LOROÑO-PINO, MARIA A.; GARCIA-REJON, JULIAN E.; IBARRA-JUAREZ, LUIS

    2010-01-01

    We report the development of universal primers for the reverse-transcription polymerase chain reaction (RT-PCR) amplification and nucleotide sequence analysis of actin cDNAs from taxonomically diverse mosquito species. Primers specific to conserved regions of the invertebrate actin-1 gene were designed after actin cDNA sequences of Anopheles gambiae, Bombyx mori, Drosophila melanogaster, and Caenorhabditis elegans. The efficacy of these primers was determined by RT-PCR with the use of total RNA from mosquitoes belonging to 30 species and 8 genera (Aedes, Anopheles, Culex, Deinocerites, Mansonia, Psorophora, Toxorhynchites, and Wyeomyia). The RT-PCR products were sequenced, and sequence data were used to design additional primers. One primer pair, denoted as Act-2F (5′-ATGGTCGGYATGGGNCAGAAGGACTC-3′) and Act-8R (5′-GATTCCATACCCAGGAAG-GADGG-3′), successfully amplified an RT-PCR product of the expected size (683-nt) in all mosquito spp. tested. We propose that this primer pair can be used as an internal control to test the quality of RNA from mosquitoes collected in vector surveillance studies. These primers can also be used in molecular experiments in which the detection, amplification or silencing of a ubiquitously expressed mosquito housekeeping gene is necessary. Sequence and phylogenetic data are also presented in this report. PMID:20649132

  18. Urban mosquito species (Diptera: Culicidae) of dengue endemic communities in the Greater Puntarenas area, Costa Rica.

    PubMed

    Calderón-Arguedas, Olger; Troyo, Adriana; Solano, Mayra E; Avendaño, Adrián; Beier, John C

    2009-12-01

    Field studies were conducted to determine the mosquito species richness in the urban area of Greater Puntarenas in Costa Rica. Two cross-sectional entomological surveys were performed in seven localities of Puntarenas: one survey was performed during the wet season and the other during the dry season. The sections evaluated were determined by applying a stratified cluster sampling method using satellite imagery, and a sample of 26 cells (100 x 100m) was selected for the study. The number of cells per locality was proportional to the area of each locality. The presence of mosquito larvae and pupae in water-filled artificial and natural containers was determined in each cell. Infestation was expressed as a diversity index per type of container (Ii). Eight types of larvae were identified (Aedes aegypti, Culex quinquefasciatus, Culex interrogator, Culex nigripalpus, Culex corniger, Culex tarsalis, Limatus durhamii and Toxorhynchites theobaldi) and in two cases it was only possible to identify the genus (Culex sp. and Uranotaenia sp.). A. aegypti was the most common species followed by C. quinquefascitus. Diversity of wet environments can explain the co-occurrence of various culicid species in some localities. Although A. aegypti is the only documented disease vector in the area, C quinquefasciatus, C nigripalpus, and the other species of Culex could be considered potential vectors of other pathogens. The presence and ecology of all mosquito species should be studied to optimize surveillance and prevention of dengue and to prevent the emergence of other mosquito-transmitted diseases. PMID:20073347

  19. Urban mosquito species (Diptera: Culicidae) of dengue endemic communities in the Greater Puntarenas area, Costa Rica

    PubMed Central

    Troyo, Adriana; Solano, Mayra E.; Avendaño, Adrián; Beier, John C.

    2010-01-01

    Field studies were conducted to determine the mosquito species richness in the urban area of Greater Puntarenas in Costa Rica. Two cross-sectional entomological surveys were performed in seven localities of Puntarenas: one survey was performed during the wet season and the other during the dry season. The sections evaluated were determined by applying a stratified cluster sampling method using satellite imagery, and a sample of 26 cells (100×100m) was selected for the study. The number of cells per locality was proportional to the area of each locality. The presence of mosquito larvae and pupae in water-filled artificial and natural containers was determined in each cell. Infestation was expressed as a diversity index per type of container (Ii). Eight types of larvae were identified (Aedes aegypti, Culex quinquefasciatus, Culex interrogator, Culex nigripalpus, Culex corniger, Culex tarsalis, Limatus durhamii and Toxorhynchites theobaldi) and in two cases it was only possible to identify the genus (Culex sp. and Uranotaenia sp.). A. aegypti was the most common species followed by C. quinquefascitus. Diversity of wet environments can explain the co-occurrence of various culicid species in some localities. Although A. aegypti is the only documented disease vector in the area, C quinquefasciatus, C. nigripalpus, and the other species of Culex could be considered potential vectors of other pathogens. The presence and ecology of all mosquito species should be studied to optimize surveillance and prevention of dengue and to prevent the emergence of other mosquito-transmitted diseases. PMID:20073347

  20. An updated checklist of mosquito species (Diptera: Culicidae) from Madagascar

    PubMed Central

    Tantely, Michaël Luciano; Le Goff, Gilbert; Boyer, Sébastien; Fontenille, Didier

    2016-01-01

    An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species). This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species), Aedes (35 species), Anopheles (26 species), Coquillettidia (3 species), Culex (at least 50 species), Eretmapodites (4 species), Ficalbia (2 species), Hodgesia (at least one species), Lutzia (one species), Mansonia (2 species), Mimomyia (22 species), Orthopodomyia (8 species), Toxorhynchites (6 species), and Uranotaenia (73 species). Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%). Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27%) with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar. PMID:27101839

  1. Updated Checklist of the Mosquitoes (Diptera: Culicidae) of French Guiana.

    PubMed

    Talaga, Stanislas; Dejean, Alain; Carinci, Romuald; Gaborit, Pascal; Dusfour, Isabelle; Girod, Romain

    2015-09-01

    The incredible mosquito species diversity in the Neotropics can provoke major confusion during vector control programs when precise identification is needed. This is especially true in French Guiana where studies on mosquito diversity practically ceased 35 yr ago. In order to fill this gap, we propose here an updated and comprehensive checklist of the mosquitoes of French Guiana, reflecting the latest changes in classification and geographical distribution and the recognition of current or erroneous synonymies. This work was undertaken in order to help ongoing and future research on mosquitoes in a broad range of disciplines such as ecology, biogeography, and medical entomology. Thirty-two valid species cited in older lists have been removed, and 24 species have been added including 12 species (comprising two new genera and three new subgenera) reported from French Guiana for the first time. New records are from collections conducted on various phytotelmata in French Guiana and include the following species: Onirion sp. cf Harbach and Peyton (2000), Sabethes (Peytonulus) hadrognathus Harbach, Sabethes (Peytonulus) paradoxus Harbach, Sabethes (Peytonulus) soperi Lane and Cerqueira, Sabethes (Sabethinus) idiogenes Harbach, Sabethes (Sabethes) quasicyaneus Peryassú, Runchomyia (Ctenogoeldia) magna (Theobald), Wyeomyia (Caenomyiella) sp. cf Harbach and Peyton (1990), Wyeomyia (Dendromyia) ypsipola Dyar, Wyeomyia (Hystatomyia) lamellata (Bonne-Wepster and Bonne), Wyeomyia (Miamyia) oblita (Lutz), and Toxorhynchites (Lynchiella) guadeloupensis (Dyar and Knab). At this time, the mosquitoes of French Guiana are represented by 235 species distributed across 22 genera, nine tribes, and two subfamilies. PMID:26336249

  2. Lack of greater seroconversion of rhesus monkeys after subcutaneous inoculation of dengue type 2 live-virus vaccine combined with infection-enhancing antibodies.

    PubMed Central

    Kraiselburd, E N; Lavergne, J A; Woodall, J P; Kessler, M J; Meier, G; Chiriboga, J; Moore, C G; Sather, G E; Pomales, A; Maldonado, E; Rivera, R

    1981-01-01

    Four groups of six nonimmune male rhesus monkeys were inoculated subcutaneously with formulations of dengue type 2 vaccine virus DEN-2/S-1. Group A received 1.9 x 10(4) plaque-forming units of vaccine in normal human serum albumin diluent. Group B received the same dose combined with a dengue type 2-immune human serum diluted 1:1,600, beyond its neutralization endpoint of 1:300, but having an immune enhancement titer of 250,000. Groups C and D received 10-fold dilutions of these respective formulations. No migration-inhibitory factor was found when peripheral blood mononuclear leukocytes obtained on day 68 post-immunization from monkeys of all experimental groups were tested. No viremia was detected in any of the monkeys when sera taken on postvaccination days 1 through 12 were inoculated into adult Toxorhynchites amboinensis mosquitoes and LLC-MK2 cells. By day 89, four of the six monkeys had seroconverted by the neutralization test in each of groups A, B, and C, and three of five monkeys in group D (one monkey died from cardiac collapse after anesthesia) had seroconverted. Immune enhancement of dengue virus infection is known to occur in humans and monkeys circulating heterologous flavivirus antibodies. In this study, there was no enhancing effect when antibody was mixed with dengue type 2 vaccine virus and injected subcutaneously. PMID:7024129

  3. [Specific diversity and culicidian nuisance in the villages of N'gatty and Allaba in laguna area of Ivory Coast].

    PubMed

    Fofana, D; Konan, K L; Djohan, V; Konan, Y L; Kon, A B; Doannio, J M C; N'goran, K E

    2010-12-01

    Entomological surveys were undertaken between June and December 2006 in N'gatty and Allaba. These villages are located in southern Ivory Coast in a laguna area in Dabou department. In these villages, there are large swampy areas, which have caused the multiplication of anthropophilic Culicidae. Mosquitoes have been collected at preimaginal stage at the time of the larval prospecting and at adult stage through human landing catch. Larval collections have been made using the classic method of "dipping". Larvae have been identified to the genus level. Then, they have been bred in the laboratory to identify adults. Adults collection has been made once a month during three consecutive nights by human landing catch inside houses. Adults have been identified to the specific level. Eight genera of mosquitoes have been collected in these two villages: Aedes, Anopheles, Coquillettidia, Culex, Eretmapodites, Mansonia, Toxorhynchites and Uranotaenia. Twenty-four species have been listed during this stu y. The genus Mansonia is the most predominant with 86% (N = 15,811) and 80% (N = 1,385), respectively, in N'gatty and Allaba. The average biting rate per day varies between N'gatty and Allaba. It is estimated to 308 bites per human per night (b/h/n) in N'gatty and 72 b/h/n in Allaba. In these villages, mosquito nuisance is mainly due to Mansonia with 264 b/h/n and 58 b/h/n, respectively, in N'gatty and Allaba. However, Anopheles gambiae s.l. average rate was 12 b/h/n in N'gatty and 2 b/h/n in Allaba. PMID:20632142

  4. Spinosad: a biorational mosquito larvicide for use in car tires in southern Mexico

    PubMed Central

    2012-01-01

    Background Car tires are important habitats for mosquito development because of the high density populations they can harbor and their presence in urban settings. Water in experimental tires was treated with one of three insecticides or an untreated control. Aquatic invertebrates were sampled at weekly intervals. Eggs, larval and pupal samples were laboratory-reared to estimate seasonal fluctuations in Aedes aegypti and Ae. albopictus abundance. Results Spinosad treatments at 1 or 5 ppm (mg a.i./liter) provided 6–8 weeks of effective control of Ae. aegypti, Ae. albopictus, Culex quinquefasiatus and Cx. coronator larvae, both in the dry season and the rainy season when mosquito populations increased markedly in southern Mexico. Spinosad continued to provide partial control of larvae for several weeks after initial recolonization of treated tires. The larvicidal performance of VectoBac 12AS (Bacillus thuringiensis var. israelensis) was relatively poor with one week of complete control of Aedes spp. larvae and no discernible control of Culex spp., whereas the duration of larvicidal activity of 1% temephos mineral-based granules was intermediate between those of VectoBac and spinosad treatments. Populations of chironomids, ostracods and Toxorhynchites theobaldi were generally reduced in spinosad and temephos treatments, but were similar in control and VectoBac treatments. Conclusion The present study is the first to report spinosad as an effective larvicide against Cx. coronator, which is currently invading the southern United States. These results substantiate the use of spinosad as a highly effective mosquito larvicide, even in habitats such as unused car tires that can represent prolific sources of adult mosquitoes. PMID:22608138

  5. Entomofaunal diversity of tree hole mosquitoes in Western and Eastern Ghats hill ranges of Tamilnadu, India.

    PubMed

    Senthamarai Selvan, P; Jebanesan, A; Reetha, D

    2016-07-01

    The distribution and abundance of various mosquito vectors is important in the determination of disease prevalence in disease endemic areas. The aim of the present study was to conduct regular entomological surveillance and to determine the relative abundance of tree hole mosquito species in Tamilnadu, India. In addition to this, the impact of weather-conditions on tree hole mosquito population were evaluated between June, 2014 and May, 2015. Six hills ranges viz., Anaimalai hills, Kodaikanal hills, Sitheri hills, Kolli hills, Yercaud hills, and Megamalai were selected, the immatures collected from tree holes by the help of suction tube. Collections were made at dusk and dawn at randomly selected 15 different tree species. The collected samples were stored and morphologically identified to species level in the laboratory. Mosquito diversity was calculated by Simpson's and Shannon-Weiner diversity indicies with spatial and temporal aspects. Over 2642 mosquitoes comprising the primary vectors of dengue, chickungunya, malaria, filariasis were identified. Other species collected from the fifteen sites in each hill during the study included Christophersiomyia annularis, Christophersiomyia thomsoni, Downsiomyia albolateralis, Downsiomyia nivea and Toxorhynchites splendens, etc. Study revealed high species diversity and relative density associated with different study sites. Based on the Shannon diversity index high number of species was recorded with Aedes pseudoalbopicta (0.0829) followed by Ae. aegypti (0.0805) and least species was recorded as Anopheles elegans (0.0059). The distribution of the primary vectors of DF along the high occurrence was evident with most study sites representing proportions of this vector population. This showed the high risk level associated with the livestock movement in amplification and circulation of the virus during the outbreaks. The findings of this study, therefore, demonstrated the potential vulnerability of nomadic communities to infection by arboviral diseases transmitted by mosquito vectors. PMID:27016014

  6. Humming in Tune: Sex and Species Recognition by Mosquitoes on the Wing

    PubMed Central

    Gibson, Gabriella; Warren, Ben

    2010-01-01

    Mosquitoes are more sensitive to sound than any other insect due to the remarkable properties of their antennae and Johnstons organ at the base of each antenna. Male mosquitoes detect and locate female mosquitoes by hearing the females flight tone, but until recently we had no idea that females also respond to male flight tones. Our investigation of a novel mechanism of sex recognition in Toxorhynchites brevipalpis revealed that male and female mosquitoes actively respond to the flight tones of other flying mosquitoes by altering their own wing-beat frequencies. Malefemale pairs converge on a shared harmonic of their respective fundamental flight tones, whereas same sex pairs diverge. Most frequency matching occurs at frequencies beyond the detection range of the Johnstons organ but within the range of mechanical responsiveness of the antennae. We have shown that this is possible because the Johnstons organ is tuned to, and able to detect difference tones in, the harmonics of antennal vibrations which are generated by the combined input of flight tones from both mosquitoes. Acoustic distortion in hearing organs exists usually as an interesting epiphenomenon. Mosquitoes, however, appear to use it as a sensory cue that enables malefemale pairs to communicate through a signal that depends on auditory interactions between them. Frequency matching may also provide a means of species recognition. Morphologically identical but reproductively isolated molecular forms of Anopheles gambiae fly in the same mating swarms, but rarely hybridize. Extended frequency matching occurs almost exclusively between males and females of the same molecular form, suggesting that this behavior is associated with observed assortative mating. PMID:20976515

  7. Mosquito larvicidal and antimicrobial activity of synthesized nano-crystalline silver particles using leaves and green berry extract of Solanum nigrum L. (Solanaceae: Solanales).

    PubMed

    Rawani, Anjali; Ghosh, Anupam; Chandra, Goutam

    2013-12-01

    Silver nanoparticles (AgNPs) that are synthesized by using aqueous extracts of Solanum nigrum L., is a simple, non-toxic and ecofriendly green material. The present study is based on assessments of the larvicidal and antimicrobial activities of the synthesized AgNPs from fresh leaves, dry leaves and green berries of S. nigrum against larvae of Culex quinquefasciatus and Anopheles stephensi and four human pathogenic and five fish pathogenic bacteria respectively. The synthesized nanoparticles are characterized with UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscope (TEM) analysis. The nanoparticles are spherical to polyhedral in shape with size of 50-100nm (average size of 56.6nm). In larvicidal bioassay with synthesized AgNPs, highest mortality are observed at 10ppm against An. stephensi with LC50 values of 1.33, 1.59, 1.56ppm and LC90 values of 3.97, 7.31, 4.76ppm for dry leaves, fresh leaves and berries respectively. Antibacterial activity test reveals better results against fish pathogenic bacteria than human pathogenic bacteria. Non target organism like Toxorhynchites larvae (mosquito predator), Diplonychus annulatum (predatory water-bug) and Chironomus circumdatus larvae (chironomid) are also exposed to respective lethal concentrations (to mosquito larvae) of dry nanoparticles and no abnormality in the non target organisms are recorded. These results suggest that the synthesized AgNPs of S. nigrum have the potential to be used as an ideal eco-friendly compound for the control of the mosquito larvae and harmful bacteria. PMID:24055718