From a discarded heavy-equipment tire (ca. 57 liter) at an industrial construction site, we collected 655 (86.0%) Orthopodomyia signifera, 23 (3.0%) Toxorhynchites rutilus septentrionalis, 17 (2.2%) Aedes japonicus japonicus, and 67 (8.8%) Culex pipiens pipiens. Although larvae of Aedes albopictus and Aedes triseriatus were not collected from this container, both species were prevalent as host-seeking adults and readily collected as larvae from other containers at this site. Laboratory trials to test the survival of prey (Ae. albopictus, Cx. p. pipiens, or Or. signifera) in the presence of Tx. rut. septentrionalis showed that survival of prey larvae differed among species. Multiple comparisons revealed that Ae. albopictus had the lowest and Or. signifera the highest survival in the presence of Tx. rut. septentrionalis. Survival of Or. signifera and Cx. p. pipiens was not significantly different from one another, but both were different from Ae. albopictus. Further testing is warranted to test other factors responsible for differences in the interspecific relationship between Or. signifera and other species in tree hole communities. PMID:19852230
Farajollahi, Ary; Kesavaraju, Banugopan; Nelder, Mark P; Crans, Scott C; Gaugler, Randy
According to the immunocompetence handicap hypothesis, males with attractive sexual ornamentation are more handicapped than their less ornamented rivals because of the immunosuppressive androgens required for the production of secondary sexual characters. Here we studied the predictions of the hypothesis in a wild cyprinid fish, the roach (Rutilus rutilus). We assayed (1) sexual ornamentation (breeding tubercles), (2) circulating androgens (11-ketotestosterone
Raine Kortet; Anssi Vainikka; Markus J. Rantala; Ilmari Jokinen; Jouni Taskinen
The present study deals with aspects of the brain development in the roach, Rutilus rutilus, a common mid-European cyprinid fish. The morphogenesis of selected brain areas from hatching to early juveniles was examined on serial paraffin cross-sections. From early juveniles to large adults, brain growth was quantitatively analyzed by computer-aided planimetry. The hatchlings of roach show a cytologically distinct optic
Roland Brandstätter; Kurt Kotrschal
A study exploiting the gravimetric method did not reveal identical development of paired parts of the roach (Rutilus rutilus) brain. In the studied sample, the proportion of fish with left or right asymmetry of this organ was 1: 1. The specificity\\u000a of fluctuating asymmetry in studied plastic parameter depending on the fish age and growth was analyzed. In the ontogenetic
M. G. Talikina; Yu. G. Izyumov; N. I. Komova
Endocrine-disrupting chemicals, known to be present in the environment, have great potential for interfering with reproductive health in wildlife and humans. There is, however, little direct evidence that endocrine disruption has adversely affected fertility in any organism. In freshwater and estuarine fish species, for example, although a widespread incidence of intersex has been reported, it is not yet known if intersexuality influences reproductive success. The purpose of this study was, therefore, to determine gamete quality in wild intersex roach (Rutilus rutilus) by assessing sperm characteristics, fertilization success, and ability to produce viable offspring. The results clearly demonstrate that gamete production is reduced in intersex roach. A significantly lower proportion of moderately or severely feminized fish (17.4% and 33.3%, respectively) were able to release milt compared with normal male fish from contaminated rivers (in which 97.6% of the males were able to release milt), reference male fish (97.7%), or less severely feminized intersex fish (experiment 1: 85.8%, experiment 2: 97%). Intersex fish that did produce milt produced up to 50% less (in terms of volume per gram of testis weight) than did histologically normal male fish. Moreover, sperm motility (percentage of motile sperm and curvilinear velocity) and the ability of sperm to successfully fertilize eggs and produce viable offspring were all reduced in intersex fish compared with normal male fish. Male gamete quality (assessed using sperm motility, sperm density, and fertilization success) was negatively correlated with the degree of feminization in intersex fish (r = -0.603; P < 0.001) and was markedly reduced in severely feminized intersex fish by as much as 50% in terms of motility and 75% in terms of fertilization success when compared with either less severely feminized intersex fish or unaffected male fish. This is the first evidence documenting a relationship between the morphological effects (e.g., intersex) of endocrine disruption and the reproductive capabilities of any wild vertebrate. The results suggest that mixtures of endocrine-disrupting substances discharged into the aquatic environment could pose a threat to male reproductive health. PMID:12135890
Jobling, Susan; Coey, S; Whitmore, J G; Kime, D E; Van Look, K J W; McAllister, B G; Beresford, N; Henshaw, A C; Brighty, G; Tyler, C R; Sumpter, J P
Roach (Rutilus rutilus) from Danish streams that receive discharges of domestic sewage effluent were examined for the presence of alterations to gonadal development. In male roach, intersex was observed at a prevalence of 4.5–5% at reference sites and 6.7–6.5% at sewage effluent-impacted sites. A positive correlation was found between sewage effluent load and intersex frequency among male roach. The highest
Lisette B. Bjerregaard; Bodil Korsgaard; Poul Bjerregaard
A phylogeographic analysis of mitochondrial DNA sequence variation was carried out to infer the geographical distribution of the genealogical lineages and the historical demography of roach Rutilus rutilus (L.). A total of 265 individuals from 52 sites covering most of the Eurasian distribution range were sequenced for a 475 bp fragment of the mitochondrial cytochrome b gene. The monophyletic roach contained two deep clades that dated back to the Pliocene. The Ponto-Caspian clade comprised populations from Greece to Siberia with a likely palaeorefugium at the west coast of the Caspian Sea. This clade largely corresponds to individuals with morphological features described as Rutilus heckelii. The west European clade included individuals from central and western Europe with the Danube and Dniester basins as possible palaeorefugia. This clade largely corresponds to individuals with morphological features described as R. rutilus. A suture-zone of the two main lineages was observed along the coastal region of the Black Sea. The neutrality tests and the mismatch distributions indicated a demographic expansion during the Middle-Pleistocene for both clades. PMID:20738542
Larmuseau, M H D; Freyhof, J; Volckaert, F A M; Van Houdt, J K J
Synopsis This paper reviews investigations on the ecophysiology of a population of roach, Rutilus rutilus, from a subalpine oligotrophic lake in the Austrian Tirol. Metabolic responses to season and temperature were studied in whole animals, tissues and selected enzymes. The exponent of the relationship between body mass and three levels of the metabolic rate of acclimated fish was 0.82 ±
Franz Koch; Wolfgang Wieser; Harald Niederstätter
The chronic effects that polychlorinated biphenyls (PCBs) have on the activities of proteinases and carbohydrates in intestinal\\u000a mucosa and chyme in juvenile roach Rutilus rutilus (L.) have been studied for the first time. Upon consuming food with PCB 50.8 ng\\/g wet weight for 218 days, the exposition\\u000a of fingerlings in aquariums with dirt bottoms (contents PCB 425.6 ng\\/g dry weight)
I. L. Golovanova; V. V. Kuzmina; G. M. Chuiko; N. V. Ushakova; A. A. Filippov
The environmental influence on Chernobyl-derived 137Cs levels in perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) was revealed using partial least-squares regression (PLS). The 53 environmental predictors used describe land use in catchment areas, various catchment area and lake characteristics, lake water chemistry, and fish stock composition. The study showed a profound effect of land use on the 137Cs
Fish reproduction is subjected to worrying trends in many aquatic environments. In this study, we report the absence of histological\\u000a and biochemical alterations in fish sampled in a low contaminated site (characterised by the absence of detectable oestrogenic\\u000a activity and mutagenicity in sediment extracts). A total of 474 roach (Rutilus rutilus) were monthly sampled during 18 months, and no intersex fish
Perrine Geraudie; Marie Gerbron; Elisabeth Hill; Christophe Minier
The aim of this study was to assess the effects of galactooligosaccharide (GOS), on the growth performance, stress resistance and intestinal microbiota of Caspian roach (Rutilus rutilus) fry. Specimens (1.36 ± 0.03 g) were fed either a basal control diet (0% GOS, non-supplemented) or the basal diet supplemented with 1% and 2% of GOS. After 7 weeks of the feeding trials, growth factors (final weight, weight gain, specific growth rate, condition factor and food conversion ratio) as well as body composition, resistance to salinity stress and autochthonous intestinal microbiota were assessed. Results demonstrated that at the end of the trial growth factors (final weight, weight gain, SGR, FCR) were significantly higher in 2% GOS fed fish (P < 0.05). In addition, supplementation of GOS significantly increased both survival rate (P < 0.05), and resistance to a salinity stress challenge of prebiotic fed groups (P < 0.05). However, body composition and the total autochthonous intestinal heterotrophic bacteria counts remained unaffected in different treatments (P > 0.05). Nevertheless, autochthonous lactic acid bacteria levels were significantly elevated in fish fed 2% dietary GOS (P < 0.05). These results confirm that GOS improves growth performance, stress resistance and modulates intestinal microbiota by increasing lactic acid bacteria of Caspian roach fry, a very important fish species in the Caspian Sea. PMID:23973845
Hoseinifar, Seyed Hossein; Khalili, Mohsen; Khoshbavar Rostami, Hosseinali; Esteban, M Ángeles
The roach (Rutilus rutilus) has become a sentinel species for the study of sexual disruption in wild fish populations as a consequence of exposure to endocrine disrupting chemicals (EDCs). Little is known, however, about the normal ontogeny of sexual development in this species. Here, we analyzed the ontogeny of sexual development in captive-bred roach and assessed how growth rate and fish size affected the timing of both sexual differentiation and sexual development over a 2-year period. Ovarian differentiation was first recorded at 68 days post-fertilization (dpf) and this preceded testicular differentiation (first recorded at 98 dpf). In contrast, sexual maturation occurred at an earlier age in males (300 dpf) compared with females (728 dpf). No differences in body size (length or weight) were recorded between male and female roach until the fish were 415 dpf. Studies on three populations of roach which grew at different rates showed that the timing of sexual differentiation was highly variable and more related to fish size than to fish age. Time to sexual maturation was also variable among populations but, subsequent to their first year of life, gonadal status was less well associated with fish size. Interestingly, the sex ratio of the population was biased towards females in populations that grew more rapidly during early life. The findings presented here provide a valuable foundation of work to support both field- and laboratory-based assessments on the effects of EDCs, and other stressors, on sexual differentiation and development in the roach. PMID:18496855
Paull, G C; Lange, A; Henshaw, A C; Tyler, C R
Wild male roach (Rutilus rutilus) living in U.K. rivers contaminated with estrogenic effluents from wastewater treatment works show feminized responses and have a reduced reproductive capability, but the chemical causation of sexual disruption in the roach has not been established. Feminized responses were induced in male roach exposed to environmentally relevant concentrations of the pharmaceutical estrogen 17alpha-ethinylestradiol, EE2 (up to 4 ng/ L), during early life (from fertilization to 84 days posthatch, dph), and these effects were signaled by altered patterns of expression of two cloned roach estrogen receptor (ER) subtypes, ERalpha. and ERbeta, in the brain and gonad/ liver. Transactivation assays were developed for both roach ER subtypes and the estrogenic potencies of steroidal estrogens differed markedly at the different ER subtypes. EE2 was by far the most potent chemical, and estrone (E1, the most prevalent environmental steroid in wastewater discharges) was equipotent with estradiol (E2) in activating the ERs. Comparison of the EC50 values for the compounds tested showed that ERbeta was 3-21-fold more sensitive to natural steroidal estrogens and 54-fold more sensitive to EE2 as compared to ERalpha. These findings add substantial support to the hypothesis that steroidal estrogens play a significant role in the induction of intersex in roach populations in U.K. rivers and that the molecular approach described could be usefully applied to understand interspecies sensitivity to xenoestrogens. PMID:17539551
Katsu, Yoshinao; Lange, Anke; Urushitani, Hiroshi; Ichikawa, Rie; Paull, Gregory C; Cahill, Laura L; Jobling, Susan; Tyler, Charles R; Iguchi, Taisen
Roach (Rutilus rutilus) from Danish streams that receive discharges of domestic sewage effluent were examined for the presence of alterations to gonadal development. In male roach, intersex was observed at a prevalence of 4.5-5% at reference sites and 6.7-6.5% at sewage effluent-impacted sites. A positive correlation was found between sewage effluent load and intersex frequency among male roach. The highest frequency of intersex (26.5%) was found in the stream Kristrup Landkanal, which had the highest percentage and load of sewage effluent (87,578 population equivalents). Further, a tendency to an average higher severity of the phenomenon (calculated as an intersex index value) was seen in males from streams impacted by sewage effluent compared to males from reference sites. However, this was significant only in male fish from Egaa Brook. Among roach from the Kristrup Landkanal 5.8% of male and 0.8% of female roach were infected with the parasite Pleistophora mirandellae, causing degenerative changes in testes and ovaries. No correlation was seen between the intersex condition and the presence of P. mirandellae in the gonads of roach. PMID:16054215
Bjerregaard, Lisette B; Korsgaard, Bodil; Bjerregaard, Poul
Alterations in development and reproduction as a consequence of exposure to endocrine-disrupting chemicals (EDCs) have been demonstrated in many wildlife species. Animals living in, or closely associated with, the aquatic environment are particularly vulnerable to endocrine disruption because thousands of chemicals are actively disposed into rivers, estuaries and seas. Fish have thus been a focus in endocrine disruption studies, and some of the most comprehensive studies on the disruption of sexual development and function are on the roach (Rutilus rutilus). This paper provides a critical analysis of the roach as a sentinel for studies into endocrine disruption. The paper starts by describing what is known on the basic reproductive biology of the roach, information essential for interpreting chemical effect measures on sexual development and function. We then analyze where and how the roach has been applied to improve our understanding of the estrogenic nature of discharges from wastewater treatment works (WWTWs) and describe the phenomenon of feminized male roach in UK rivers. In this paper, the causation of these effects and issues of relative susceptibility and sensitivity of the roach to the effects of estrogenic EDCs are addressed. The paper then describes the ongoing work on the development of genetic and genomic resources for roach and analyses how these are being applied in studies to understand the mechanisms of disruption of sexual development. Finally, the paper addresses the biological significance of sexual disruption and intersex for the individual and discusses the possible implications for wild populations. PMID:17975536
Tyler, Charles R; Lange, Anke; Paull, Gregory C; Katsu, Yoshinao; Iguchi, Taisen
Feminized responses are widespread in wild populations of roach, Rutilus rutilus, living in UK rivers, and some of these responses have been shown to arise as a consequence of exposure to wastewater treatment works (WwTW) effluent discharges and the endocrine disrupting chemicals (EDCs) they contain. The causation of the ovotestis condition in wild roach, however, has yet to be established. Furthermore, the impact of long-term exposure to WwTW effluents on the reproductive fitness of wild fish populations is not known, and this information is crucial for population level effect assessments. We undertook a chronic exposure of roach to a treated estrogenic wastewater effluent for up to 3.5 years to assess principally for effects on subsequent reproductive fitness, as determined through parentage analysis on offspring from a competitive breeding study. In generating the fish for the breeding study we found that exposure to full strength WwTW effluent until sexual maturity resulted in sex reversal in almost all males in the population; 98% of the exposed fish were phenotypic females, containing ovaries. Furthermore, fish exposed to a 50% dilution of WwTW effluent contained ovotestis (21% of the male roach) that was absent from the control population. In competitive breeding studies, and applying DNA microsatellites to assess parentage, we show that presumptive females exposed to sexual maturity to WwTW effluent bred normally, albeit in the absence of nonexposed females, but putative sex-reversed males breeding as females contributed poorly, if at all, in a breeding population, depending on the competition. These novel findings on sex reversal add a new dimension for impact assessments of exposure to WwTW effluents on fish populations. PMID:21207934
Lange, Anke; Paull, Gregory C; Hamilton, Patrick B; Iguchi, Taisen; Tyler, Charles R
This paper presents the results of analyses of the dietary composition of 0+ roach, Rutilus rutilus (L.), and bleak, Alburnus alburnus (L.) inhabiting Lake Gos³awskie. The following hypotheses were verified: (i) the dietary composition of fish changes over time; (ii) fish somatic growth causes variation in the spectrum of dietary components. Species richness in the diets of roach and bleak
Efficiency of feeding on zebra mussel ( Dreissena polymorpha ) by common bream ( Abramis brama ), white bream ( Blicca bjoerkna ), and roach ( Rutilus rutilus ): the effects of morphology and behavior
We compared efficiencies of feeding on zebra mussel (Dreissena polymorpha) by three syntopic cyprinids: common bream (Abramis brama), white bream (Blicca bjoerkna), and roach (Rutilus rutilus). Empirical feeding efficiency (the ratio of food energy content to food capture and processing costs) is largely determined by the time needed to handle prey, rather than by the energy required for specific feeding
Leo A. J. Nagelkerke; Ferdinand A. Sibbing
The environmental influence on the mercury content in roach (Rutilus rutilus L.) is investigated using partial least square regression on 46 environmental variables describing the land use in the catchment area, various catchment area and lake characteristics, lake water chemistry, and fish stock. The Hg content in the fish from the 78 investigated circumneutral lakes is heavily influenced by the land use in their surroundings. The boreal forest lakes possessed the highest Hg levels in roach, whereas fish from lakes surrounded by arable land had lower levels. The Hg levels also showed a negative relationship to the amount of dissolved ions and the total amount of nutrients in lake water. Lake pH did not have any significant influence on the Hg content in roach in these non-acidified lakes. The Hg levels in lakes influenced by large amounts of wetland were less well explained by the presently investigated environmental variables, which implies that the Hg burden in fish from this kind of lake is governed by other factors. PMID:11291453
In this study, although the highest production of two physiologically significant progestins in teleosts [17,20?-dihydroxypregn-4-en-3-one (17,20?-P) and 17,20?,21-trihydroxypregn-4-en-3-one (17,20?,21-P)] was observed in the period just prior to spawning in both male and female roach Rutilus rutilus, there was also a substantial production (mean levels of 5-10?ng?ml(-1) in blood; and a rate of release of 5-20?ng fish(-1) ?h(-1) into the water) in males and females in the late summer and early autumn (at least 7?months prior to spawning). During this period, the ovaries were increasing rapidly in size and histological sections were dominated by oocytes in the secondary growth phase [i.e. incorporation of vitellogenin (VTG)]. At the same time, the testes were also increasing rapidly in size and histological sections were dominated by cysts containing mainly spermatogonia type B. Measurements were also made of 11-ketotestosterone (11-KT) in males and 17?-oestradiol and VTG in females. The 3?months with the highest production of 11-KT coincided with the period that spermatozoa were present in the testes. In females, the first sign of a rise in 17?-oestradiol concentrations coincided with the time of the first appearance of yolk globules in the oocytes (in August). The role of the progestins during the late summer and autumn has not been established. PMID:23902304
Scott, A P; Hill, T; Beresford, N; Runnalls, T J; Sumpter, J P; Ellis, T
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
Southam, Andrew D; Lange, Anke; Hines, Adam; Hill, Elizabeth M; Katsu, Yoshinao; Iguchi, Taisen; Tyler, Charles R; Viant, Mark R
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.
The environmental influence on Chernobyl-derived 137Cs levels in perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) was revealed using partial least-squares regression (PLS). The 53 environmental predictors used describe land use in catchment areas, various catchment area and lake characteristics, lake water chemistry, and fish stock composition. The study showed a profound effect of land use on the 137Cs levels in fish. Radiocaesium deposited on arable land was retained in the soil to a greater extent than was 137Cs deposited on wetlands, which more easily leached out to the lake ecosystems. The 137Cs deposition close to the lakes had a more pronounced effect on 137Cs levels in the fish than did more distant deposition. The radiocaesium bioavailability is mainly governed by lake water cation content, as hardwater lakes had significantly lower 137Cs content in fish. Resuspension of 137Cs contaminated sediments only had a limited influence on the observed levels in fish. PMID:11398373
Fish reproduction is subjected to worrying trends in many aquatic environments. In this study, we report the absence of histological and biochemical alterations in fish sampled in a low contaminated site (characterised by the absence of detectable oestrogenic activity and mutagenicity in sediment extracts). A total of 474 roach (Rutilus rutilus) were monthly sampled during 18 months, and no intersex fish were recorded after careful histological examination, thus indicating that the incidence of this phenomenon may be very low under natural conditions. Furthermore, mean male plasma vitellogenin concentration was 24 ng ml(-1) and was only slightly elevated during the spawning period (up to 120 ng ml(-1)) indicating that these low values may be characteristic of a low contaminated site. Of the male roach, 45.3% were sampled, a sex-ratio that did not significantly deviated from the expected 1:1 ratio between male and female. Results also showed that natural conditions can greatly affect the reproductive cycle of roach. Gametogenesis showed a biphasic pattern with first gonad maturation between September and December and a final maturation occurring at the end of winter/early spring. Under decreasing temperatures, particularly below 6 degrees C, gametogenesis was stopped or even regressed with secondary oocytes becoming rare under histological observation. Conversely, elevated temperatures during the winter lead to an earlier gonad maturation. PMID:19680761
Geraudie, Perrine; Gerbron, Marie; Hill, Elisabeth; Minier, Christophe
Artificially cultivating Chroogomphus rutilus is too inefficient to be commercially feasible. Furthermore, isolating C. rutilus mycelia in the wild is difficult. Thus, it is important to determine the natural habitat of its fruiting body. This study focused on the ecology of the C. rutilus habitat to isolate and classify beneficial microorganisms that could affect its growth, which could be used in future research on artificial cultivation. In total, 342 isolates were isolated from soil samples collected around a C. rutilus colony in the Beijing region. Of these, 22 bacterial and 14 fungal isolates were selected for sequencing and phylogenetic analysis, based on their growth characteristics and colony morphology. Using 16S rRNA gene sequence analysis, the bacterial isolates were divided into two monophyletic clusters which had significant hits to the genera Bacillus and Pseudomonas, respectively. Using internal transcribed spacer (ITS) sequence analysis, fungal isolates were divided into four monophyletic clusters: Penicillium, Trichoderma, Mortierella, and Bionectria. Moreover, the phylogenetic diversity of these isolates was analysed. The results indicated that numerous microorganisms were present in C. rutilus habitat. This was the first reported examination of the microbiological ecology of C. rutilus.
Wang, Peng; Liu, Yu; Yin, Yonggang; Jin, Haojie; Wang, Shouxian; Xu, Feng; Zhao, Shuang; Geng, Xiaoli
The concentrations of four heavy metals (Pb, Cd, Ni and Cr) were measured in tissues of pelagic (Rutilus caspicus) and benthic (Neogobius gorlap) fishes from the Miankaleh international wetland. The maximum concentrations of Pb, Cd, Ni, and Cr (2.06, 1.20, 1.14 and 0.70 ?g g(-1), respectively) were measured in the liver of N. gorlap, while the lowest concentrations were measured in muscle tissue collected from R. caspicus (Pb 0.67; Cd 0.25; Ni 0.21 and Cr 0.08 ?g g(-1)). The mean concentrations of metals in liver of R. caspicus and N. gorlap followed a trend where Pb > Cd > Ni > Cr, whereas in R. caspicus and N. gorlap gills and N. gorlap muscle the following trend was observed Pb > Ni > Cd > Cr. The data of presented study show that the liver and gill tissues have higher metal concentrations than muscle and also the metal concentrations in tissues of N. gorlap (benthic) were higher in comparison with R. caspicus (pelagic). PMID:24064989
Alipour, Hossein; Pourkhabbaz, Alireza; Hassanpour, Mehdi
Capture rates in planktivorous fish may differ in individuals foraging alone or in a group, and this may result either from\\u000a the altered risk of predation due to vigilance sharing in the group, or from a difference in the intensity of scramble competition\\u000a for encountered prey items. Changes in capture frequency and the feeding pattern observed in young roach (Rutilus
Maciej Bartosiewicz; Z. Maciej Gliwicz
Rutilus frisii kutum (Kamensky 1901) is one of the economically important fishes that migrate for spawning to rivers in the Caspian Sea. However,\\u000a the fish populations have slowly decreased in recent years. The declining of these resources has resulted from some activities\\u000a by the Iranian Fisheries Organization (IFO is responsible for stock enhancement) to catch some broodstocks of Rutilus frisii
H. A. Abdolhay; S. K. Daud; S. Rezvani Ghilkolahi; M. Pourkazemi; S. S. Siraj; M. K. Abdul Satar
Estrogen receptor ER? and ER? heterodimerization has been implicated in cancer chemoprevention. The discovery, structural elucidation and total synthesis of a new natural product, actinopolymorphol A (1), from Actinopolymorpha rutilus (YIM45752) that preferentially induces ER?/? heterodimerization is reported. Total synthesis of 1 has allowed us to determine its absolute stereochemistry and that of a previously known deacetylated congener, and 1 represents the first member of a new class of natural products not previously recognized to modulate ER function.
Huang, Sheng-Xiong; Powell, Emily; Rajski, Scott R.; Zhao, Li-Xing; Jiang, Cheng-Lin; Duan, Yanwen; Xu, Wei; Shen, Ben
Altered sexual development in roach (Rutilus rutilus) exposed to environmental concentrations of the pharmaceutical 17alpha-ethinylestradiol and associated expression dynamics of aromatases and estrogen receptors.
Wild roach (Rutilus rutilus) inhabiting UK rivers contaminated with estrogenic effluents from wastewater treatment works show altered sexual development, including intersex, and this can impact negatively on their reproductive capabilities. The molecular events underlying these disruptions in gender assignment, however, are still poorly understood. In this study, two isoforms of aromatase (cyp19a1a and cyp19a1b) were cloned from the roach, and effects of exposure to 17alpha-ethinylestradiol (EE(2)) during early life were determined on the expression of both aromatases and on the estrogen receptors (ERs) (subtypes esr1 and esr2b) and analyzed against effects on the progression of gonadal sex differentiation. Exposure to environmentally relevant concentrations of EE(2) during the critical period of sex differentiation resulted in gonadal feminization and all roach exposed to 4 ng EE(2)/l were females. These effects on gonadal development were associated with alterations in the expression of both esr and cyp19a1 genes in bodies and heads of exposed fish with the most marked effects on the expression of esr1 and cyp19a1b. Our findings show that both aromatase isoforms and both ER subtypes are associated with sexual differentiation in roach, and alterations in their expression can signal for disruptions in sexual development. PMID:18653663
Lange, Anke; Katsu, Yoshinao; Ichikawa, Rie; Paull, Gregory C; Chidgey, Laura L; Coe, Tobias S; Iguchi, Taisen; Tyler, Charles R
PERMANENT GENETIC RESOURCES: Identification of microsatellite loci for parentage analysis in roach Rutilus rutilus and eight other cyprinid fish by cross-species amplification, and a novel test for detecting hybrids between roach and other cyprinids.
In order to identify microsatellite loci for parentage analysis in roach Rutilus rutilus, 59 published primer sets were tested on roach and eight other cyprinid fish. Twenty polymorphic loci were identified for roach, of which the polymerase chain reaction products of seven could be pooled for sequencer analysis. Together, these seven loci have an exclusion probability of 0.997 for parentage, when no parents are known. We also describe a novel test for hybrids between roach and four other cyprinids, based on intraspecies length differences of internal transcribed spacer region 1. PMID:21585822
Hamilton, P B; Tyler, C R
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-?-estradiol (E2) and 17-?-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 ?M) or butylparaben induced a twofold increase in VTG production when compared with 100 nM E2, whereas this production was only 20% with 100 ?M 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
Gerbron, Marie; Geraudie, Perrine; Rotchell, Jeanette; Minier, Christophe
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
Liney, Katherine E; Jobling, Susan; Shears, Jan A; Simpson, Peter; Tyler, Charles R
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.
Liney, Katherine E.; Jobling, Susan; Shears, Jan A.; Simpson, Peter; Tyler, Charles R.
Wild roach (Rutilus rutilus) have been found with intersex gonads in rivers throughout the United Kingdom. The incidence of intersexuality is strongly correlated with discharges of estrogenic treated sewage effluent into those rivers, and this has led to the hypothesis that estrogenic chemicals in effluents are feminizing wild male fish. In this study, early-life stage roach (50 days post hatch, dph) were exposed for 150 days to a graded concentration (0%, 12.5%, 25%, 50%, and 100%) of treated sewage (primarily domestic) effluent to examine the effects of exposure on sexual differentiation and development. Measurement of steroid estrogens and alkylphenolic chemicals in the effluent and a resulting dose-dependent induction of vitellogenin (VTG; a female-specific, estrogen-dependent plasma protein) confirmed that the fish had been exposed and responded to "estrogen" in the effluent. Exposure to treated sewage effluent induced feminization of the reproductive ducts in "male" roach in a dose-dependent manner (in full-strength effluent, 100% of the fish had feminized ducts), indicating that the disruption of the gonad ducts seen in wild roach is the result of exposure to treated sewage effluents during early-life stages. There were no effects of treated sewage effluent exposure on germ cell development; therefore, no oocytes occurred in the testes of the feminized male roach. Subsequent, depuration of the effluent exposed fish in "clean" water for 150 days resulted in a reduction in plasma VTG but no alteration of the feminized ducts, indicating that the effect of the treated sewage effluent on reproductive duct development was permanent. The causality of oocytes in the testes of wild male roach therefore remains to be elucidated. PMID:11351715
Rodgers-Gray, T P; Jobling, S; Kelly, C; Morris, S; Brighty, G; Waldock, M J; Sumpter, J P; Tyler, C R
Effluents from wastewater treatment works (WwTWs) contain estrogenic substances that induce feminizing effects in fish, including vitellogenin (VTG) synthesis and gonadal intersex. Fish vary in their responsiveness to estrogenic effluents, but the physiological basis for these differences are not known. In this study, uptake of estrogen from two WwTW effluents (measured in hydrolyzed bile) and estrogenic response (VTG induction) were compared in a salmonid (rainbow trout, Onchorhynchus mykiss) and a cyprinid fish (roach, Rutilus rutilus). Immature rainbow trout were more responsive than maturing roach to the estrogenic effluents. The more potent of the two estrogenic effluents (containing between 24.3 and 104.1 ng estradiol-17beta equivalents/L [E2eq/L]) resulted in a 700-fold and 240-fold induction of plasma VTG in male and female trout, respectively, but only a 4-fold induction in roach (and in males only). The less potent effluent (varying between 4.1 and 6.8 ng E2eq/L) induced VTG in the trout only, with a 4-fold and 18-fold induction in males and females, respectively. In fish exposed to tap water, the estrogenicity of the hydrolyzed bile was 0.03+/-0.01 ng E2eq/microL (for both sexes in trout), 0.18+/-0.04 ng E2eq/microL in male roach, and 0.88+/-0.15 ng E2eq/microL in female roach. The higher bile content of estrogen in control roach reflected their more advanced sexual status (and thus higher endogenous estrogen) compared with the immature female trout. In trout maintained in effluents, the bile content of estrogen was 100-fold and 30-fold higher than controls at WwTW A and B, respectively. Bioconcentration factors (BCFs) for estrogenic activity in bile were between 16 344 and 46 134 in trout and between 3543 and 60 192 in roach (no gender differences were apparent). There were strong correlations between VTG induction and the estrogenic activity of bile extracts for both trout and roach. The results confirm that estrogenic contaminants bioconcentrate to a high degree in fish bile and that the level (and nature) of this accumulation may accountfor responsiveness to the endocrine disruptive effects of estrogenic effluents. Immature fish were the more appropriate life stage for quantifying estrogen exposure and uptake in bile, as they contain little circulating endogenous oestrogen compared with sexual maturing fish. The nature of the estrogenic contaminants is detailed in an accompanying paper. PMID:15884355
Tyler, C R; Spary, C; Gibson, R; Santos, E M; Shears, J; Hill, E M
Response surface methodology was used to optimize the extraction of crude polysaccharides from the fruiting bodies of Gomphidius rutilus. A central composite design was adopted to determine the combination of factors (extraction time, extraction temperature, extraction frequency, and ratio of water to raw material) that resulted in the maximum crude polysaccharide production. Results showed that the optimum extraction conditions were as follows: extraction temperature, 95°C; ratio of water to raw material, 16; extraction time, 2.5 h; and extraction frequency, 4. Under these conditions, the experimental yield of crude polysaccharides was 8.02±0.15%, which well agreed with the predicted yield. Evaluation of the antioxidant activity in vitro suggested that the crude polysaccharides had high scavenging activity for superoxide anion, hydroxyl, and 1,1-diphenyl-2-picrylhydrazyl radicals. The crude polysaccharides also showed strong reducing power. Thus, they can be used as natural antioxidants in functional foods or medicine. PMID:23544565
Wang, Chenyu; Zhang, Jing; Wang, Fei; Wang, Zhanyong
Two novel polysaccharide fractions, GRMP1 and GRMP2, were isolated from the mycelium of Gomphidius rutilus through submerged fermentation. GRMP1 and GRMP2 had similar average molecular weights (35 and 31 kDa, respectively), and were composed of glucose and xylose at molar ratios of 0.46:1 and 0.63:1, respectively. In vitro antioxidant tests showed that GRMP1 and GRMP2 partly scavenged superoxide radical but almost had no scavenging effect on 1,1-diphenyl-2-picrylhydrazyl free radical. The effect of GRMP1 on hydroxyl radicals was stronger than that of GRMP2. Both GRMP1 and GRMP2 had relatively low reducing power and significant lymphocyte proliferation activity. In the presence of concanavalin A or lipopolysaccharide as mitogens for lymphocytes, the lymphocyte proliferation activity increased for GRMP1 but not for GRMP2 within the test dosage range. PMID:23399275
Gao, Chanjuan; Wang, Yanhua; Wang, Chenyu; Wang, Zhanyong
Tajan River is among the most significant rivers of the Caspian Sea water basin. In this study, the concentration of Cr, Cu, Fe, Mn, Ni, Pb, Cd, and Zn were determined in brain, heart, liver, gill, bile, and muscle of Rutilus frisii kutum which has great economic value in the Mazandaran state. Trace element levels in fish samples were analyzed by means of atomic absorption spectrometry. Nearly all non-essential metals levels (Ni, Pb, Cd) detected in tissues were higher than limits for fish proposed by FAO/WHO, EU, and TFC. Generally, non-essential metals (Ni, Pb) were so much higher in muscle than the essential metals (Cu, Zn, and Mn) except Fe, which was higher than other metals in nearly all parts, except in gills. Fe distribution pattern in tissues was in order of heart>brain>liver>muscle>bile>gill. Distribution patterns of metal concentrations in the muscle of fish as a main edible part followed the sequence: Fe>Pb>Ni>Cu>Mn>Zn>Cd. PMID:20978865
Eslami, Shahram; Hajizadeh Moghaddam, Akbar; Jafari, Naser; Nabavi, Seyed Fazel; Nabavi, Seyed Mohammad; Ebrahimzadeh, Mohammad Ali
Effect of ultralow concentrations of N-methyl-N?-nitro-N-nitrosoguanidine upon early development in roach ( Rutilis rutilus ): Intestine carbohydrase activities and kinetic characteristics of carbohydrate hydrolysis in the intestine of underyearlings
The prolonged effects of short-term action of N-methyl-N?-nitro-N-nitrosoguanidine (MNNG) in low concentrations 3 × 10?7 to 3 × 10?1 mg\\/l upon roach (Rutilus rutilus) early development have been studied. It was revealed that the treatment resulted in an increase in fish length and weight,\\u000a in a decrease in total amylolytic and saccharase activities, and in different changes in parameters of
I. L. Golovanova; M. G. Talikina; A. A. Filippov; Yu. G. Izyumov; Yu. V. Chebotareva
Twenty-nine morphometric and seven meristic characteristics were analyzed to identify non-reproductive (NR) and reproductive (R) female kutum, Rutilus frisii kutum. Seventy one samples of mature-size female kutum were collected from coastal waters of the southwest Caspian Sea during spawning season. Principal component analysis, discriminant function analysis, cluster analysis, and a Kruskal-Wallis test were used to identify the two types of
P. Kashefi; A. Bani; E. Ebrahimi
The aim of present study was to determine the LC50/96 h value of copper sulfate and determine the growth performance of Caspian Sea kutum) Rutilus frisii kutum (fingerlings during 60-days sub-lethal copper (Cu). After acclimation period to two weeks, for determine the LC50/96 h value, total of 27 aquarium with a capacity of 60 L each stocked with 10 fishes an aquarium. Tunney four aquarium and 8 concentrations of (Cu) composed the 24 treatments while 3 other aquaria were used as control. For each treatment, three replications were conducted. And experiment to determine the growth performance fish were transferred into fiberglass aquaria of 200 L water capacity for growth trials. The treated fish were kept in the aquarium containing sub-lethal concentrations of Cu (0.11 and 0.23 mg L(-1)) and affected to grow for 60 days, while control fish were placed in metal free water. The results indicated that median lethal concentrations (LC50) of copper to Caspian Sea kutum for 96 h exposure was 2.310 ppm. The chronic sub-lethal water-borne Cu exposure to the fish exerted that fish had significantly decreased final body weight in comparison to control group. The copper sulfate also had significant negative effects on specific growth rate (SGR) and feed conversion efficiency (FCE) in comparison to those fed the control group. The feed conversion ratio (FCR) and condition factor (CF) were significantly increased in comparison with the control group (P?0.05). Also survival rate in experimental treatments in comparison with control group, was significantly decreased (P?0.05). The treated fish exhibited significantly lower body weight and length gains than that of control. The increments of fish weights, fork and total lengths, condition factor, feed intake and condition factor of treated and control fish varied significantly during study period. Hence, concluded that copper sulfate is toxic for Caspian sea kutum (Rutilus frisii kutum). PMID:24133647
Gharedaashi, Esmail; Nekoubin, Hamed; Imanpoor, Mohammad Reza; Taghizadeh, Vahid
Monitoring quantitative parameters of parasitism by ligula intestinalis (Cestoda: Diphyllobothridae) was performed by examining 516 fish belonging to two introduced freshwater species: Rutilus rubilio (350 individuals) and Scardinius erythrophthalmus (166 individuals). These fish were collected in two dam reserves in Tunisia, Sidi Salem and Nebhana. The analysis of the aquatic bird's composition in these two reserves revealed the existence of piscivorous bird species that were previously reported as final host of Ligula. Monitoring the bird's composition highlighted higher relative abundance and frequency in Sidi Salem than in Nebhana dam reserve. The analyses of the prevalence, mean intensity and abundance of the parasite revealed the most important values in roach, Rutilus rubilio which seems to be the preferential second intermediate host of the parasite Ligula intestinalis in these environments. Comparative analysis of parasitism in both explored sites suggests that Ligula intestinalis presents two different strategies of infestation. In Sidi Salem reserve, which is larger than Nebhana and containing on important and diversified piscivorous species, the parasite infects a maximum of host individuals with low parasite mean intensity values. However, at Nebhana, which is a smaller reserve, the parasite infects fewer individuals than Sidi Salem but with higher mean intensity. The highest prevalence values were recorded in large size classes of roach species in Sidi Salem reserve. PMID:21077391
Bahri-Sfar, L; Haddaoui, N; Bouzid, W; Essetti, I; Qninba, A; Ben Hassine, O K
In a population of red-backed voles (Myodes rutilus) that live in optimal habitats (mountain taiga of North-Eastern Altai) in the years of peak density we have observed total suppression of sexual maturation of young animals which is known to be the main mechanism of density regulation. Increase of voles' local density is accompanied by the increase of glucocorticoids in blood of mature and immature individuals of both sexes that argues for the important role of hypothalamic-pituitary-adrenal axis in density dependent regulation. Another population of red-backed voles from south-west Siberia that live in suboptimal habitats (Novosibirsk city vicinity), had significantly lower density. Here, the dynamics of demographic traits and endocrine status of the individuals did not correlate with interannual fluctuations of abundance and density. Even though, the possibility that in suboptimal conditions local density occasionally reaches the values sufficient for the induction of self-regulation cannot be excluded. PMID:22567967
Novikov, E A; Panov, V V; Moshkin, M P
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.
Alves, M J; Coelho, M M; Prospero, M I; Collares-Pereira, M J
Can. Ent. 109: 93-94 (1977) The mosquito To~orhynchites rulilus septentrionalis (Dyar and Knab) is recorded for the first time in Canada. The species was found breeding in a water-filled rot cavity in a tree in the deciduous forest of Point Pelee National Park. The distribution of the species for which this record represents an extension of the range is discussed.
D. J. Parker
It has been shown that chronic exposure to dietary mercury results in the intensive accumulation of this metal in roach yearlings.\\u000a The concentrations of accumulated mercury in their organisms were proportional to the amount of metal added to water of experimental\\u000a tanks. Increased Hg content in the organisms (0.05–0.16 mg\\/kg) of developing juvenile roaches decreases the activity of digestive\\u000a carbohydrases
I. L. Golovanova; V. T. Komov; V. A. Gremyatchikh
An ultrastructural study was performed on chloride cells of euryhaline R.r.Caspicus of south of Caspian Sea. The chloride cells are distributed in the interlamellar region of filaments. They are oval to elongated form with an apical positioned nucleus, expanded tubular system and heteromorphic mitochondria. These cells are surrounded by pavement cell and accessory cell. A small and depressed surface formed by pavement cells is in contact with the aquatic milieu. There is also channel system in accessory cells. One of the typical features was the important changes in microtubules and mitochondria of chloride cells in some fishes. Swelling and rupture of cristae and degeneration of microtubules were from these changes. PMID:19757132
Saadatfar, Zohreh; Shahsavani, Davar
A model that assesses risks posed by feminization to wild populations of roach was developed. A population life table matrix model that considered both sexes and a newly developed fertility kinetic function was applied to calculate the intrinsic population growth rate (lambda) of roach populations where males had been feminized. The maximum sustainable yield (MSY) was used to quantify the effect of various degrees of feminization on sustainability of exploited fisheries. Risk of extinction was calculated for wild roach populations. The results of the simulations suggested that (a) In the absence of fishing pressure lambda would only be decreased 1.5-1.7% even in the presence of a 100% incidence of intersex; (b) in the presence of selective fishing, the occurrence of intersex could significantly increase the extinction risk of local roach populations; (c) the benchmark value for the severity index of intersex and sex ratio required for a sustainable population of roach were estimated to be 1.13 and 0.57, respectively. The approach presented here provides a tool to (1) understand effects of male's feminization on population dynamics; (2) assess extinction risk of wild roach populations from feminization; (3) assist environmental managers in making policy decisions relative to fishery resource conservation. PMID:19921911
An, Wei; Hu, Jianying; Giesy, John P; Yang, Min
Disruption in gonadal development of wild roach living in U.K. rivers receiving large volumes of treated sewage effluent is manifest in a variety of ways, ranging from malformation of the germ cells and\\/or reproductive ducts to altered gamete produc- tion. Intersex fish were also found to have an altered endocrine status and an elevated concentration of plasma vitellogenin. Go- nadal
S. Jobling; N. Beresford; M. Nolan; T. Rodgers-Gray; G. C. Brighty; J. P. Sumpter; C. R. Tyler
Disruption in gonadal development of wild roach living in U.K. rivers receiving large volumes of treated sewage effluent is manifest in a variety of ways, ranging from malformation of the germ cells and/or reproductive ducts to altered gamete production. Intersex fish were also found to have an altered endocrine status and an elevated concentration of plasma vitellogenin. Gonadal growth was inhibited only in severely intersex fish, whereas progression of spermatogenesis was delayed in a large proportion of all intersex and exposed male fish. In contrast to the effects observed in the intersex and exposed male fish, the maturation of ovaries in female fish inhabiting effluent-contaminated rivers appeared to be less obviously affected, although a higher incidence of oocyte atresia was found in the effluent-exposed fish compared with the reference fish. A positive correlation was found between the proportion of female tissue in the gonads of intersex fish and their plasma vitellogenin concentration, suggesting that vitellogenin can be an indicator for the level of gonadal disruption in intersex roach. The estradiol-17beta concentration in intersex fish was intermediate between the concentration found in males and females, and the plasma testosterone was between 2- and 3-fold higher in intersex fish compared with male fish. These data suggest a link between altered endocrine status in intersex and female fish and gonadal disruption. Spermiation was also affected in roach living in effluent-impacted rivers: a lower proportion of fish were found releasing sperm, and in those intersex fish that were spermiating, a reduced milt volume and a reduced sperm density were found. All intersex fish had malformations of the reproductive duct(s), and in severely affected fish, the ducts were occluded, thus preventing release of gametes. In view of the widespread occurrence of intersexuality in wild fish populations in rivers throughout the United Kingdom, assessment of the reproductive capabilities of these intersex roach is clearly needed to understand the impact of this phenomenon on roach fertility. PMID:11804939
Jobling, S; Beresford, N; Nolan, M; Rodgers-Gray, T; Brighty, G C; Sumpter, J P; Tyler, C R
Predator-induced respiratory responses of juvenile vendace, whitefish, perch and roach were studied in an intermittent-flow respirometer by creating visual contact between test fishes and predators (juvenile northern pike). Vendace and whitefish always responded to the presence of pike with increased oxygen consumption. The response of perch was the opposite: oxygen consumption decreased to near the standard respiratory level. Roach responded
Hannu Huuskonen; Juha Karjalainen
We checked whether the induced anti-predator defences of zebra mussels are able to affect the predation success of roach,\\u000a being one of the most efficient zebra mussel predators in Europe. Previously, several anti-predator defences of mussels have\\u000a been observed in the presence of roach, including stronger attachment, aggregation forming and inhibition of upward movement.\\u000a However, the actual efficiency of these
Jaros?aw Kobak; Tomasz Kakareko
The development of spawning in perch, pike and roach in Lake Geneva has been studied by means of artificial spawning substrates, laid at different depths, from 1984 to 1993. In Lake Geneva, perch spawned in May. A rise of surface water temperature up to 14 °C stimulated spawning activity while bad weather (surface temperature at 10 °C) induced a spread
C. Gillet; J. P. Dubois
Biomagnification of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) studied in pike ( Esox lucius), perch ( Perca fluviatilis) and roach ( Rutilus rutilus) from the Baltic Sea
Pike, perch and roach from rural waters of the Baltic Sea were investigated for possible biomagnification of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). For this we used data on ?15N, weight and sex of the fish. We were able to separate body size effects from trophic position effects on biomagnification. Both these parameters lead to biomagnification of PCBs
Sven Burreau; Yngve Zebühr; Dag Broman; Rasha Ishaq
The north and south basins of Windermere in the English Lake District, UK, support autumn- and spring-spawning populations\\u000a of Arctic charr, Salvelinus alpinus, which have been studied since the 1930s. Continuous investigations of the population dynamics of Arctic charr at this lake\\u000a have involved gill netting since 1939, collection of fishery catch-per-unit-effort data since 1966, and hydroacoustic surveys\\u000a since 1990.
Ian J. Winfield; Janice M. Fletcher; J. Ben James
Changes in the numbers of dominating parasites as indicators of the condition of roach, Rutilus rutilus lacustris, and dace Leuciscus leuciscus baicalensis (Pisces: Cyprinidae) populations in the transect Selenga River – River Delta – Lake Baikal
Changes in the numbers of 10 species of parasites belonging to 5 classes of roach and Siberian dace were investigated in the transect “Selenga River – Delta – Lake Baikal” in 2001–2006. The numbers either increased along this transect (myxosporea Myxobolus bramae, monogeneans of genus Dactylogyrus, diplostomatids metacercariae and Rhipidocotyle campanula, parasitic copepodes Ergasilus sieboldi and E. briani) or decreased
N. M. Pronin; M. D. Batueva; L. D. Sondueva; T. G. Burdukovskaya; Zh. N. Dugarov; S. V. Pronina
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 se-
Sa-nga Pattanakitsakul; Kobporn Boonnak; Kusuma Auethavornanan; Aroonroong Jairungsri; Thaneeya Duangjinda; Punjaporn Puttatesk; Supatra Thongrungkiat; Prida Malasit
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); or (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-laboratory 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
Murrell, Ebony G; Juliano, Steven A
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
Pattanakitsakul, Sa-Nga; Boonnak, Kobporn; Auethavornanan, Kusuma; Jairungsri, Aroonroong; Duangjinda, Thaneeya; Puttatesk, Punjaporn; Thongrungkiat, Supatra; Malasit, Prida
All adult mosquitoes take sugar meals, and most adult females also take blood meals to develop eggs. Salivary glands (SG) of males are thus much smaller and do not contain many of the antihemostatic and antiinflammatory compounds found in females. In the past 5 years, transcriptome analyses have identified nearly 70 different genes expressed in adult female SG. For most of these, no function can be assigned in either blood or sugar feeding. Exceptionally, Toxorhynchites mosquitoes are unusual in that they never feed on blood, and the SG of adults are identical in both sexes. Transcriptome analysis of the adult SG of this mosquito was performed to increase knowledge of the evolution of blood feeding—and to identify polypeptide families associated with sugar feeding—in mosquitoes.
Calvo, E.; Pham, V. M.; Ribeiro, J. M. C.
The use of Toxorhynchites brevipalpis as a system for the propagation and isolation of bluetongue virus (BTV) was investigated. BTV was found to multiply in T. brevipalpis after infection by intrathoracic inoculation. Virus concentrations of up to 6.9 log 10 TCID50 per mosquito were found within 7 days of infection and were maintained for at least 6 days. Virus could be detected by an indirect fluorescent antibody test applied to head and thorax tissue smears. These results are comparable to those obtained after inoculation of Culicoides variipennis with the same virus. Comparison of T. brevipalpis and baby hamster kidney (BHK) cells as systems for isolation of BTV showed that there was little difference in sensitivity between the two systems for the stock BTV used. Field samples were not available for test. It was concluded that the use of T. brevipalpis as an isolation system for BTV would have no apparent advantage if BHK cells were available. PMID:6141782
Jennings, M; Boorman, J; Mellor, P S
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
Macías-Duarte, Alberto; Alvarado-Castro, J Andrés; Dórame-Navarro, María E; Félix-Torres, A Amalia
Thirty-one viruses recently placed in taxa were studied for their replication in Toxorhynchites amboinensis by intrathoracic inoculation. Results were compared to those obtained in vitro in mammal and insect cell cultures. These findings provide presumptive evidence for the association of eighteen of these viruses with arthropod vectors. PMID:2575779
Zeller, H G; Mitchell, C J
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
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
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.
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
Assurance of identity and quantity is an indispensable part of quality control in the manufacture of vaccines. Dengue-1 PDK13, dengue-2 PDK53, dengue-3 PGMK30F3 and dengue-4 PDK48 in the live attenuated tetravalent dengue vaccine were assayed by identification and quantitation in a mosquito system (Toxorhynchites splendens). Each serotype of dengue virus was identified by dengue specific monoclonal antibodies in the indirect fluorescent antibody test. Virus content was estimated by calculating the 50% mosquito infectious dose (MID50). Differences from 0 to +/-0.5 log10 were observed between the original monovalent titer and that from the blend which showed no significant difference at 95% confidence limit (P < 0.05). This result indicates that there is no interference between dengue serotypes in mosquitoes infected by intrathoracic inoculation with the virus mixture. It can be also concluded that this mosquito system can be used as an effective measure for infectivity titration of each component in the tetravalent dengue vaccine. PMID:10075167
Jirakanjanakit, N; Khin, M M; Yoksan, S; Bhamarapravati, N
Aquatic organisms often detect predators via water-borne chemical cues, and respond by showing reduced activity. Prey responses may be correlated with the concentration of predation cues, which would result in graded antipredator behavioral responses that adjust potentially costly behavioral changes to levels that are commensurate with the risk of predation. Larvae of the predatory mosquito Toxorhynchites rutilus prey upon other container-dwelling insects, including larvae of the mosquito Ochlerotatus triseriatus. Previous work has established that O. triseriatus reduce movement, foraging, and time below the surface, and increase the frequency of resting at the surface, in the presence of water-borne cues from predation by T. rutilus. We tested whether these responses by O. triseriatus are threat sensitive by recording behavior of fourth instar larvae in two runs of an experiment in which we created a series of concentrations (100, 10, 1, 0.1, and 0.01% and 100, 70, 40, 20, and 10%) of water that had held either O. triseriatus larvae alone (control) or a T. rutilus larva feeding on O. triseriatus (predation). We also tested whether associated effects on time spent feeding are threat sensitive by determining whether frequencies of filtering or browsing are also related to concentration of cues. The frequencies of resting and surface declined, whereas frequency of filtering (but not browsing) increased more rapidly with a decrease in concentration of predation cues compared with control cues. Thus, O. triseriatus shows a threat sensitive behavioral response to water-borne cues from this predator, adjusting its degree of behavioral response to the apparent risk of predation.
Kesavaraju, Banugopan; Damal, Kavitha; Juliano, Steven A.
The nonhematophagous mosquito Toxorhynchites (Tx.) splendens was found to be the most susceptible to type 2 dengue (D-2) and Japanese encephalitis (JEV) viruses among three hosts examined by virus titration and replication assays. After inoculation with D-2, the number of viral antigen positive cells in the head, thorax and abdomen increased up to day 15 and D-2 reached the maximum titer of 8.4 log10 PFU/g in the head on day 15. Hemocytes were the earliest cell type that could be detected as D-2 antigen positive on day 2. Multiplication of JEV was faster than that of D-2 in the mosquito. The number of JEV antigen positive cells in each part of the mosquito increased up to day 3, JEV reaching the maximum titer of 8.0 log10 PFU/g in the abdomen on day 3. Hemocytes and fat body cells (FBC) could be detected as JEV antigen positive cells on day 1. The time course of D-2 and JEV infection suggested that intrathoracically inoculated viruses were probably initially phagocytosed by hemocytes and/or FBC, and multiplied primarily in their cytoplasm. The infected hemocytes were then transported by the flow of body fluid and viruses were disseminated to other susceptible organs, such as ganglia, salivary glands, etc. The results obtained indicate that the course of infection of D-2 and JEV in Tx. splendens is similar to that in vector mosquitoes. Tx. splendens is therefore very useful for the study of these viruses. PMID:2891346
Yamamoto, N; Kimura, T; Ohyama, A
Mercury (Hg) concentrations in burbot (Lota lota), perch (Perca fluviatilis), northern pike (Esox lucius), roach (Rutilus rutilus), whitefish (Coregonus lavaretus) and peled (C. peled) were monitored in 18 reservoirs situated in western and northern Finland over a period of 16 years (1979–1994). The reservoirs were impounded from 1964 to 1980. The surface areas ranged between 1 and 417 km2. Data
Fish schools are aggregative structures encountered in all types of aquatic environments but have as yet been little studied in freshwaters except at small spatial scales. This study represents the three dimensional description of juvenile fish schools (Perca fluviatilis and Rutilus rutilus) in a lake environment using high resolution multibeam sonar system operating at a frequency of 455 kHz, composed
Jean Guillard; Patrice Brehmer; Michel Colon; Yvon Guennégan
Evolutionary relationships of red-backed voles and their relatives were examined and used to test biogeographic hypotheses. Sequences of the mitochondrial cytochrome b gene were obtained for 25 individuals representing Alticola macrotis, Clethrionomys californicus, C. gapperi, C. glareolus, C. rutilus, and C. rufocanus. These were combined with 21 partial sequences from GenBank for C. regulus, C. rex, C. rufocanus, C. rutilus,
Joseph A. Cook; Amy M. Runck; Chris J. Conroyb
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
Brian Hayden; Domitilla Pulcini; Mary Kelly-Quinn; Martin O'Grady; Joe Caffrey; Aisling McGrath; Stefano Mariani
The spawning periodicity of eight fish species was investigated in three English lowland rivers over a 6 year period from patterns in 0þ year fish standard length (LS) distributions. A single cohort of 0þ year dace Leuciscus leuciscus, roach Rutilus rutilus and perch Perca fluviatilis was observed each year, suggesting that these species spawned only once annually. By contrast, populations
A. D. Nunn; J. P. Harvey; I. G. Cowx
The somatic growth rate of 0+ fish of the six major species in Dutch shallow eutrophic lakes, bream (Abramis brama), roach (Rutilus rutilus), pikeperch (Stizostedion lucioperca) (planktivorous and piscivorous), perch (Perca fluviatilis), ruffe (Gymnocephalus cernuus), and smelt (Osmerus eperlanus), was analysed by using a differential equation. This equation models the instantaneous growth rate of a fish as a temperature-dependent power
W. M. Mooij; E. H. Van Nes
In this study we identified some of the predators of the freshwater snail Viviparus ater and estimated offspring survival to the end of the first summer in a natural population. Newborn V. ater were eaten by the fish Barbus barbus, Rutilus rutilus, Scardinius erythrophtalmus and Tinca tinca. Out of 137 guts of Abramis brama caught in Lake Zürich 1 contained
G. Keller; G. Ribi
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 com- mon 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 dis- ruption
Susan Jobling; Richard Williams; Andrew Johnson; Ayesha Taylor; Melanie Gross-Sorokin; Monique Nolan; Charles R. Tyler; Ronny van Aerle; Eduarda Santos; Geoff Brighty
The high incidence of intersex roach ( Rutilus rutilus) in some United Kingdom rivers that has been associated with exposure to sewage treatment works (STWs) effluent led us to hypothesize that top predator fish also may be affected by estrogenic chemicals, because they are likely to bioaccumulate lipophilic compounds through a predator-prey relationship. To investigate this possibility, pike (Esox lucius)
Emma Vine; Jan Shears; Ronny van Aerle; Charles R. Tyler; John P. Sumpter
The phylogeography of the Holarctic Microtus oeconomus in Russian Far East, near the Beringia, was studied using mitochondrial cytochrome b (Cytb) gene sequences. In comparison with the Cytb data of the Holarctic Myodes rutilus and the Palaearctic My. rufocanus previously studied by us, those of Mi. oeconomus showed similar local differentiation patterns to those of My. rutilus and obviously differed
Masahiro A. Iwasa; Victor A. Kostenko; Lyubov V. Frisman; Irina V. Kartavtseva
Data on Zn, Cu, Pb, Ni, Cr, Sn, Mo concentrations in some food fish in Baikal Lake and Bratsk reservoir have been compared. The muscles, skin and gills of roach and perch (Rutilus rutilus and Perca fluviatis L.) were analysed. The conditions of atomic-emission analysis, detection limits, reproducibility, coefficients of transformation from the wet to dry mass and to an
A. I. Kuznetsova; O. V. Zarubina; G. A. Leonova
Cold-active burbot (Lota lota (L.)) display reduced food intake during the summer. The impact of temperature on their energy budget was investigated in\\u000a starved fish in a laboratory setting, simulating summer (20°C) and winter (4°C) conditions, to elucidate the impact of high\\u000a temperature on burbot metabolism. Metabolic effects in burbot were compared to roach (Rutilus rutilus (L.)), which typically fast in winter.
Maaike Binner; Werner Kloas; Iris Hardewig
;Introduction of the invasive Asian cyprinid fish Pseudorasbora parva into a 0.3 ha pond in England with a fish assemblage that included Cyprinus carpio, Rutilus rutilus and Scardinius erythrophthalmus resulted in their establishment of a numerically dominant population in only 2 years; density estimates exceeded 60 ind. m?2 and they comprised >99% of fish present. Stable isotope analysis (SIA) revealed significant trophic overlap between
J. Britton; Gareth Davies; Chris Harrod
From 1990–1993 juvenile pike (Esox lucius) were stockedeach spring in the eutrophic Lake Lyng (9.9 ha, max. depth 7.6 m,mean depth 2.4 m) in densities between 515 and 3616 pikeha-1. In 1989–90 the fish population consisted mainly ofroach (Rutilus rutilus), rudd(Scardinius erythrophthalmus), perch (Percafluviatilis) and ruffe (Gymnocephalus cernuus), andtotal fish biomass was estimated at 477 kg ha-1. Prior tostocking pike
Søren Berg; Erik Jeppesen; Martin Søndergaard
Estrogens play an important role in many physiological processes of vertebrates, mediated by estrogen receptors (ERs). The full length of the cDNAs for ER?, ER?1, and ER?2 were isolated and characterized from Gobiocypris rarus. G. rarus ERs shared the highest amino acid identities with counterparts of three cyprinidae species (Pimephales promelas ER?: 91.1%, Rutilus rutilus ER?1: 92.9%, Tanichthy albonubes ER?2:
Houpeng Wang; Jingjing Wang; Tingting Wu; Fang Qin; Xiaoqi Hu; Lihong Wang; Zaizhao Wang
The Dniester River is one of the largest rivers in Eastern Europe and receives input from numerous anthropogenic activities. In October 2001, fish samples (Abramis brama, Rutilus rutilus heckeli, Perca fluviatilis, Chondrostoma nasus, Carassius auratus gibelio, and Cyprinus carpio) were collected and analyzed for metals and various pesticides. Maximum total DDT pesticide concentrations were between 27.7 and 34.2ng\\/g wet weight
Yelena Sapozhnikova; Natalia Zubcov; Sarah Hungerford; Luke A. Roy; Nina Boicenco; Elena Zubcov; Daniel Schlenk
No recovery was recorded in the shallow and eutrophic Lake Væng, Denmark, after a sewage diversion in 1981, due to an internal\\u000a phosphorus loading and a dominance of planktivorous fish. In order to improve lake water quality by means of biomanipulation,\\u000a a total of 2.5 tons of bream (Abramis brama) and roach (Rutilus rutilus) was removed during 1986 and the
M. Søndergaard; E. Jeppesen; E. Mortensen; E. Dall; P. Kristensen; O. Sortkjaer
Spores of Myxobolus pseudodispar from plasmodia occurring in the roach muscles (Rutilus rutilus) were studied by light, transmission and scanning electron microscopy, before and after discharge of their polar filaments. Scanning microscopy reveals that discharged polar filaments bear no spines and their walls are slightly folded. Polar filaments of M. pseudodispar have been compared with stinging threads of the parasitic cnidarium Polypodium hydriforme. PMID:11601388
Ibragimov, A Iu
\\u000a Our story on the feminization of wild roach (Rutilus rutilus) populations in English Rivers is a product of many years of research in collaboration with various colleagues. Over the\\u000a past 20 years, we have shown that male roach are being feminized as a consequence of exposure to effluents from wastewater\\u000a treatment works (WwTWs). Here we provide a history of wastewater
Charles R. Tyler; Amy L. Filby
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.
KESAVARAJU, BANUGOPAN; JULIANO, STEVEN A.
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
Johnson, B J; Sukhdeo, M V K
Background The role of hybridization in generating diversity in animals is an active area of discovery and debate. We assess hybridization across a contact zone of northern (Myodes rutilus) and southern (M. gapperi) red-backed voles using variation in skeletal features and both mitochondrial and nuclear loci. This transect extends approximately 550 km along the North Pacific Coast of North America and encompasses 26 populations (n = 485). We establish the history, geographic extent and directionality of hybridization, determine whether hybridization is ongoing, and assess the evolutionary stability of novel genomic combinations. Results Identification of M. rutilus and M. gapperi based on the degree of closure of the post-palatal bridge was concordant with the distribution of diagnostic nuclear MYH6 alleles; however, an 80 km zone of introgressed populations was identified. The introgressant form is characterized by having mitochondrial haplotypes closely related to the northern M. rutilus on a nuclear background and morphological characteristics of southern M. gapperi. Conclusion Introgression appears to have been historic as pure populations of M. rutilus are now isolated to the north from introgressants or pure M. gapperi by the LeConte Glacier. As we do not find pure M. rutilus or M. gapperi individuals throughout the distribution of the introgressant form, it appears that the introgressants are a self-sustaining entity not requiring continued hybridization between pure parental forms to generate this novel combination of characters.
Runck, Amy M; Matocq, Marjorie D; Cook, Joseph A
We utilised DNA analysis to detect the presence of the digenean Phyllodistomum folium in three cyprinid species, Scardinius erythrophthalmus, Cyprinus carpio and Rutilus rutilus. DNA sequencing of the region containing the genes ITS1-5.8S-ITS2 revealed 100% sequence identity between DNA from the sporocysts found in zebra mussels and DNA from adults located in the urinary system of 29 cyprinid fish. A second genetically different (variation=1.6%) sequence was observed in two samples from R. rutilus. In our opinion, the existence of a complex of species reported as P. folium is supported by recent genetic studies, including our own results. The overall prevalence of P. folium in mussels from the Ebro River was 4.67% in 2006, although during the summer months the rates frequently exceeded 10%. PMID:20971214
Peribáñez, Miguel A; Ordovás, Laura; Benito, Josep; Benejam, Lluís; Gracia, María J; Rodellar, Clementina
The fine structural organization and dimensions of spermatozoa from species of 4 subfamilies of the Cyprinidae (Barbus barbus, Carassius carassius, Cyprinus carpio carpio, Cyprinus carpio haematopterus, Abramis brama, Alburnoides bipunctatus, Alburnus alburnus, Chalcalburnus chalcoides mento, Chondrostoma nasus, Hypophthalmichthys molitrix, Leuciscus cephalus, Phoxinus phoxinus, Rutilus rutilus, Rutilus meidingerii, Scardinius erythrophthalmus, Vimba vimba and Ctenopharyngodon idella) are compared with each other as well as with results from other studies. Based on these descriptions it is investigated whether sperm structure reveals correlations with the existing systematics and if it could be a useful taxonomical parameter. The scatter plots based on the discriminate analysis and the neighbour-joining trees based on a Mahalanobis distance matrix reveal that sperm organization is related with systematics in many aspects. However, in some cases there are also clear differences between relations found on the basis of sperm morphology and between the systematic relations. PMID:19688692
Fürböck, Sonja; Lahnsteiner, Franz; Patzner, Robert A
The assemblages of young-of-the-year fish were studied in coastal lagoons in an archipelago with post-glacial land-uplift, which affects environmental gradients at local and regional scale, i.e. lagoon habitat isolation and archipelago position, respectively. The categorisation of 40 undisturbed lagoons into nine habitat types based on habitat isolation and archipelago position was supported by clear relationships with spring temperature and total fish abundance. Rutilus rutilus, breams ( Abramis/Blicca sp.) and Perca fluviatilis were the most abundant and frequently occurring species. The fish assemblage differed among the nine habitat types. Rutilus rutilus, P. fluviatilis and breams were discriminating species in the majority of habitat types with low physical harshness, whereas Alburnus alburnus and Gasterosteus aculeatus increased their contributions in habitat types with high physical harshness. Rutilus rutilus and breams were thus common in lagoons with high habitat isolation situated in the inner archipelago. These lagoons were characterised by warm water and high vegetation coverage. Gasterosteus aculeatus was restricted to lagoons with low habitat isolation and exposure and low vegetation coverage, situated in the outer archipelago. Perca fluviatilis had the widest distribution of all species. The coverage of two macrophytes, Potamogeton perfoliatus and Zannichellia palustris, and salinity matched best the distance among habitat types. These habitat characteristics, as well as the fish abundances and assemblages differed most across the habitat types in the outer and mid archipelago zones and in the lowest habitat isolation. These patterns suggest that the structuring effect of habitat isolation increases along the archipelago gradient as differences between local and regional conditions increase. In the inner archipelago, overall low physical harshness induces homogeneous conditions and the habitat isolation is less important here than in the other zones. We suggest that this difference in the relative importance of the two gradients depending on the level of respective gradient ultimately forms these heterogeneous coastal habitats in a successional landscape. Rutilus rutilus and P. fluviatilis were responsible for large parts of the assemblage patterns. Although sympatric due to similar habitat requirements, differences in dispersal capability, competitive ability and predation vulnerability may add explanation to detected differences in distribution and abundance in these two species in an open system. Our results also stress the structuring role of vegetation in terms of total coverage and species composition, as these two aspects of macrophyte diversity may act as complementary habitat modifiers across gradients of physical harshness.
Snickars, Martin; Sandström, Alfred; Lappalainen, Antti; Mattila, Johanna; Rosqvist, Kajsa; Urho, Lauri
The recent appearance of Aedes Stegomyia albopictus (Skuse) in Nuevo León (NL) worries health officials. It is a vector of dengue fever in Asia and is more resistant to lower temperatures than Ae. aegypti. The objective of this study was to learn about some ecological parameters of Ae. albopictus and their association with Ae. aegypti, and other culicids in Allende, NL, Mexico, during 1999. Allende is a small town close to metropolitan Monterrey, which has 4 million inhabitants. The design was random with monthly sampling of 175 ovitraps. Chi-square analyses were performed with data of presence, absence, frequency, and relative abundances. During the study, the species Culex tarsalis (Coquillet), Cx. thriambus (Dyar), Cx. pipiens (Linnaeus), Cx. coronator (Dyar and Knab), Ae. albopictus, Ae. aegypti, Toxorhynchites rutilus (Coquillet), and Ae. triseriatus (Say) were found. April is the month for large numbers of mosquito species. September had the highest populations in positive ovitraps (66.67%), followed by July (63.27% of traps). Aedes aegypti was the most abundant (65.13%), followed by Ae. albopictus (19.71%). Both Ae. albopictus and Ae. aegypti were found from April until December. Aedes aegypti was more abundant than Ae. albopictus, except in August, when they were similar (chi2 = 0.197, P < 0.05). We found significant association between the presence of both species for every study month (chi2 = 9.837, P < 0.05), with a contingency coefficient of 0.247. September and November were the months having the most mosquitoes in this association. Only considering Ae. albopictus, more were found in ovitraps in July (34.6%), followed by September (33.3%). However, its presence was not significant throughout the year. Of 2 zones, in town and at the river, prevalence indicated that Ae. albopictus preferred the river. This mosquito is in its establishment phase in this area and requires further studies. PMID:16646314
Mercado-Hernandez, Roberto; Aguilar-Gueta, Juan de Dios; Fernandez-Salas, Ildefoso; Earl, Paul R
In swine, the enzyme sorbitol dehydrogenase exhibits a genetically determined polymorphism as identified by multiple electrophoretic bands suggesting a tetrameric structure (Op't Hof, 1969). In order to obtain further information on the genetics of this polymorphism, a number of other vertebrate species were examined. Multiple alleles at the SDH gene locus were found in the Cyprinid fishes Leuciscus and Rutilus,
J. Op't Hof; U. Wolf; W. Krone
In this study, the antioxidant activity of mycelia from 21 wild mushrooms – Agaricus bresadolanus, Auricularia auricula-judae, Chroogomphus rutilus, Fomes fomentarius, Ganoderma lucidum, Gloeophyllum trabeum, Gymnopus dryophilus, Infundibulicybe geotropa, Inocybe flocculosa var. crocifolia, Inocybe catalaunica, Lentinula edodes, Lentinus sajor-caju, Lycoperdon excipuliforme, Macrolepiota excoriata, Morchella esculenta var. rigida, Morchella intermedia, Omphalotus olearius, Pleurotus djamor, Postia stiptica, Rhizopogon roseolus and Stropharia inuncta
Fatih Kalyoncu; Mustafa Oskay; Hüsniye Kayalar
The obligate fish ectoparasite Argulus coregoni is strictly specific to salmonids and is very rarely found on other fish species. The ability of the parasite to grow and complete its life cycle on a cyprinid host, Rutilus rutilus, was compared with that on a typical salmonid host, Oncorhynchus mykiss. Rearing experiments were run for 42 d with newly hatched metanauplii in flow-through tanks. Body length and sex of the parasites were recorded every 5 d. Growth rates on O. mykiss exceeded those on R. rutilus from the age of 2 wk, at which time the parasites reached a length of about 3.5 mm. Males grew faster than females at the beginning of the experiment up to a length of 2.5 to 3.0 mm; thereafter, a faster growth rate was observed in females. In another experiment, association of parasites with the hosts was monitored and residence time defined as the period between attachment and first detachment from the host. Longer residence time was observed on O. mykiss than on R. rutilus; female parasites stayed on both fish species longer than did males. Faster growth of parasites could be associated with longer uninterrupted periods of attachment to hosts, since frequent detachment means higher energy losses and less time available for feeding. Despite its slower growth on R. rutilus, A. coregoni matured and laid egg clutches, but took 5 d longer than on O. mykiss. The potential of A. coregoni to complete its life cycle on cyprinids could have important ecological consequences, creating an infection reservoir when the main salmonid hosts are rare or temporarily missing. PMID:15109143
Pasternak, A; Mikheev, V; Valtonen, E T
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
The relationship between the level of the intestinal mucosa amylolytic activity (AA) of juvenile goldfish Carassius auratus, carp Cyprinus carpio, roach Rutilus rutilus and perch Perca fluviatilis and the rate of water temperature increase was studied. Increase in water heating rate significantly influences AA and the level of upper lethal temperatures defined by critical thermal maximum (CTM) during different seasons. At a low rate of water temperature increase, 0.04 °C/h, AA and the level of CTM are maximal during all seasons. More rapid rates of heating, 4-50 °C/h, increase the AA during the summer and usually decrease it by 2- to 7.5-fold during other seasons. Rapid increase in ambient temperature in the autumn-winter period, unnatural for seasonal dynamics, produces a negative impact upon the fish's carbohydrate hydrolysis rate and thermal resistance. PMID:23619779
Golovanova, I L; Golovanov, V K; Smirnov, A K; Pavlov, D D
Native Eurasian otter (Lutra lutra) and introduced American mink (Mustela vison) carcasses collected throughout Ireland were screened for biliary parasites. Secondary intermediate hosts, Cyprinid fish, were also examined for Opistorchiid metacercariae. Twenty-nine mink and 24 otter gall bladders were screened for biliary parasites. A single mink and three otters were found to be infected with the digenetic trematode Pseudamphistomum truncatum. Eighty-nine percent of roach (Rutilus rutilus) from the River Shannon were infected with P. truncatum metacercariae, confirming the persistence of the parasite. This is the first record of the species in Ireland, and its recent introduction is probably related to the movement and release of Cyprinid fishes by anglers. PMID:20582437
Hawkins, Conall J; Caffrey, Joe M; Stuart, Peter; Lawton, Colin
. Persistent organochlorines, such as polychlorinated biphenyls (PCBs) including coplanar congeners, DDTs, HCHs, chlordanes\\u000a (CHLs), and HCB, were determined in the blubber of Caspian seals (Phoca caspica) and their fish diet (Rutilus sp.) collected in 1993 from the northern Caspian Sea, Russia. Notable concentrations of DDTs and HCHs were found at mean\\u000a values of 19 and 1.3 ?g\\/g on wet-weight
M. Watanabe; S. Tanabe; R. Tatsukawa; M. Amano; N. Miyazaki; E. A. Petrov; S. L. Khuraskin
Evolutionary relationships of red-backed voles and their relatives were examined and used to test biogeographic hypotheses. Sequences of the mitochondrial cytochrome b gene were obtained for 25 individuals representing Alticola macrotis, Clethrionomys californicus, C. gapperi, C. glareolus, C. rutilus, and C. rufocanus. These were combined with 21 partial sequences from GenBank for C. regulus, C. rex, C. rufocanus, C. rutilus, Eothenomys imaizumii, E. melanogaster, Phaulomys andersoni, and P. smithii. Complete sequences of three species of Microtus (M. montanus, M. oeconomus, and M. pennsylvanicus), representative species of other arvicoline genera (Myopus, Synaptomys, Arvicola, Ellobius, Ondatra, Lemmus, Dicrostonyx, and Phenacomys), and a sigmodontine representative (Peromyscus) were included as outgroups. We used maximum parsimony, maximum likelihood, distance, and Bayesian based methods and conducted statistical tests on proposed hypotheses of phylogenetic relationships and biogeographic histories. A close relationship of species representing the genera Alticola, Clethrionomys, and Eothenomys was supported (Clethrionomyini); however, the genus Clethrionomys was paraphyletic with respect to both Alticola and Eothenomys. Three major clades were identified as Asian (Eothenomys andersoni, E. smithii, C. rex, C. regulus, and C. rufocanus), Trans-beringian (Alticola macrotis, C. californicus, C. gapperi, C. glarelolus, and C. rutilus), and Taiwanese (E. melanogaster). These results are consistent with the fossil record which indicates an initial diversification in Asia followed by colonization of the Nearctic on at least two occasions. The holarctic species, C. rutilus, appears to have either reinvaded Asia from North America or colonized North America more recently (late Pleistocene) than the two species of Clethrionomys (C. gapperi and C. californicus) that are endemic to North America (early to mid-Pleistocene). Finally, C. gapperi, appears to be comprised of an eastern and a western species, the former with affinities to the Asian C. glareolus and the latter more closely related to C. californicus. PMID:15012954
Cook, Joseph A; Runck, Amy M; Conroy, Chris J
Dual-energy x-ray absorptiometry (DXA) is a nondestructive technique that can potentially measure specific components of whole-body composition in free-living and lab-raised animals. Our aim was to test the ability of DXA to measure the com- position of a common arvicoline rodent, the northern red- backed vole (Clethrionomys rutilus). We used a DXA apparatus to obtain measurements of fat mass (FM),
The difference in the mechanism of radioresistance, the strategy and the level of the adaptation are determined at Apodemus (Sylvaemus) Uralensis and Clethrionomys Rutilus living on the territory of the East Urals Radioactive Trace with the 90Sr contamination density of 180-450 Ci/km2. The mechanism of radioresistance Apodemus (Sylvaemus) Uralensis is based on the use of lipid reserves in energy provision of the physiological functions, what provided of the growth oxidation metabolism in the mitochondria. Found changes testify in favor of stress-realization mechanism of increase of the level energy homeostasis and, inquest, heightened regime of the functioning cells. As a result there is the cellular disadaptation, marked of decrease nuclear, mitochondrial proteins and process of the cellular regeneration, that put obstacles in tissue adaptation. The opposite focus of the metabolic homeostasis at Clethrionomys Rutilus points to limitation use of the lipid reserves in energy provision of the physiological functions, what provided the suppression oxidation metabolism in the mitochondria. The minimization of the functional activity cellular and subcellular structures compensate the growth of theirs numbers as a result of the level tissue and longtime adaptation. This fact characterizes more safety of the level adaptability at Clethrionomys Rutilus to radiation surroundings. PMID:19507695
Rasina, L N; Orekhova, N A
1. Free-swimming fish (Tilapia leucosticta and Rutilus rutilus) were used to determine threshold concentrations required for general anesthesia with metacaine (MS-222). The criterion for anesthesia was reached at a concentration of 1:1500 (w/w) with both fish, although the symptoms were somewhat more pronounced in Rutilus. 2. Recordings of efferent spontaneous activity in the lateral-line nerve were used as a measure of the central effect of metacaine during administration in the respiratory stream, as compared with respiration of fresh water. The reduction of activity at the end of a 3-min exposure to the drug was 70%. 3. Maximum recovery (90% of the initial activity) was reached after 30 min application of fresh water. 4. The various efferent impulse types were differentially affected by the anesthetic. 5. Direct recordings from sound-sensitive neurons in the medulla confirm the strong central effect of metacaine. 6. Irrigation of the lateral-line system with anesthetic solution also produced a reduction in afferent spontaneous activity; there was a distinct peripheral effect even at the threshold concentration. 7. Reactions of trigeminal nerve fibers to mechanical stimulation of the skin were reduced after application of a metacaine solution to the skin. This finding confirms the local anesthetic effect of the drug. 8. The anesthetic solution at a given concentration had a greater effect on the CNS than on the peripheral receptors. 9. The implications of the results with respect to the risk of misjudging the depth of general anesthesia are discussed. 10. Because of the complexity of its anesthetic efficacy, it is recommended that metacaine not be used for neurophysiological investigations, but rather that the animals be immobilized by means of muscle relaxants. PMID:193048
Späth, M; Schweickert, W
Two species of lemmings and two species of voles were fed a high fat, high cholesterol diet for several months. Clethrionomys rutilus had a moderate (2x) rise in serum cholesterol while Microtus oeconomus had a marked increase (5x); Dicrostonyx stevensoni and Dicrostonyx rubricatus had extreme increases (8x and 11x, respectively). Typical lesions of atherosclerosis were observed in all species, but D. rubricatus had significantly more severe lesions. Hepatic fatty infiltration was the principal pathologic lesion found besides atherosclerosis in those test rodents which died spontaneously. PMID:383113
Dieterich, R A; Preston, D J
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.
The mining company Karelian Pellet in northwestern Russia extracts iron ore and processes it locally into pellets. The production operations affect the environment in the form of air pollution and wastewater emissions to lakes downstream from the factory. The toxic effects of the mining effluents on gills of perch (Perca fluviatilis) and roach (Rutilus rutilus) were studied. In lakes close to the factory, heavy metal concentrations in gills were not high, even though the metal content in sediment was elevated. In fish gills the relative proportion of phosphatidylcholine was elevated and cholesterol reduced, while the histological structure of the gills was changed. The number of mucus cells, as well as the sizes and the lengths of open areas in the chloride cells, had increased in spring and summer. The hypertrophy of chloride cells is possibly caused by the increased ambient concentrations of K+ and Li+. Changes in gill cholesterol and phospholipid proportions increase the fluidity of membranes and possibly strengthen their protective qualities, counterbalancing the adverse changes in chloride cell structure. The bioavailability and toxic effects of metals on fish are reduced by the hardness and high pH of water discharged by the mining plant. PMID:15041251
Tkatcheva, Victoria; Hyvärinen, Heikki; Kukkonen, Jussi; Ryzhkov, Leonid P; Holopainen, Ismo J
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
Lazartigues, Angélique; Wiest, Laure; Baudot, Robert; Thomas, Marielle; Feidt, Cyril; Cren-Olivé, Cécile
In laboratory experiments the swimming behaviour of the ectoparasite Argulus foliaceus and its infection rates on juvenile perch (Perca fluviatilis) and roach (Rutilus rutilus) were examined. The highest infection rate and a preference for perch juveniles were obtained in darkness, the lowest infection rate and a lack of preference in the light, when aquaria with glass walls (high reflectivity) were used. In the light, when aquaria were lined with black plastic (low reflectivity) an intermediate level of infection for perch and the highest for roach was recorded. Under such conditions roach were significantly more heavily infected than perch; an attack rate 4 times greater was recorded for brighter (more reflective) roach juveniles than for perch. Within the aquaria with a low reflective interior parasites swam 4.4 times slower and were observed predominantly in the central area, while in the highly reflective aquaria fast swimming A. foliaceus were recorded mainly near the walls. The primary role of visual stimuli for the host search behavior of A. foliaceus in the light is suggested. Parasites can effectively use such stimuli only in the low reflective surroundings. Highly reflective glass aquarium walls produce numerous secondary local light sources, which cause fast, erratic parasite movements and prevent the efficient location of potential hosts. PMID:9614325
Mikheev, V N; Valtonen, E T; Rintamäki-Kinnunen, P
The choice between two alternative hosts, brown trout (Salmo trutta) and roach (Rutilus rutilus), and the response to visual and olfactory cues were studied in the ontogeny of Argulus coregoni. The initial preference of the smallest parasites for brighter roach changed at the age of 2 weeks, at the size of about 2 mm, for trout, a typical salmonid host. Younger argulids were attracted by a non-specific visual stimulus (white disc over dark background), and they did not respond to olfactory stimulation (fish-conditioned water). Later, the response to visual stimuli was modulated by trout-conditioned water, but not by that conditioned by roach. The primary role of vision, particularly in early ontogeny, is emphasized as an adaptation of A. coregoni to habitats in boreal latitudes, clear and running water with a sparse fish population. In sub-adult and adult parasites, vision is complimented by olfaction that enables them to choose hosts more precisely. The nature and adaptive significance of the ontogenetic shift in host choice by A. coregoni is discussed. PMID:14712391
Mikheev, Victor N; Pasternak, Anna F; Valtonen, E Tellervo
The Dniester River is one of the largest rivers in Eastern Europe and receives input from numerous anthropogenic activities. In October 2001, fish samples (Abramis brama, Rutilus rutilus heckeli, Perca fluviatilis, Chondrostoma nasus, Carassius auratus gibelio, and Cyprinus carpio) were collected and analyzed for metals and various pesticides. Maximum total DDT pesticide concentrations were between 27.7 and 34.2 ng/g wet weight in muscles and gonads, respectively. DDE isomers comprised up to 70% of total DDT measurement in fish tissues, indicating historical rather than recent DDT pollution. Chlordane and lindane were also detected in amounts up to 37 and 76 ng/g wet weight in gonads, respectively. Among organophosphorous pesticides, malathion showed extremely high concentrations--3 microg/g wet weight in muscles and 46 microg/g wet weight in gonads, indicating recent exposure. Copper concentrations in muscles (1.8-7.2 microg/g) exceeded Threshold Effect Concentrations for copper in fish. Detection of high concentrations of malathion and copper in fish tissues indicated potential anthropogenic stress for more sensitive aquatic biota, likely from agricultural sources in the Dniester River. PMID:15914239
Sapozhnikova, Yelena; Zubcov, Natalia; Hungerford, Sarah; Roy, Luke A; Boicenco, Nina; Zubcov, Elena; Schlenk, Daniel
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 MT(theoretical)/ MT(measured) 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
Bervoets, Lieven; Knapen, Dries; De Jonge, Maarten; Van Campenhout, Karen; Blust, Ronny
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.
Since 2007 about 200 to 300 fish per year--generally roach (Rutilus rutilus) also a few bleak (Alburnus alburnus) and eels (Anguilla anguilla)--have been collected from a number of English river sites and stored at -80°C to build up a Fish Tissue Archive as a resource for the monitoring of pollutants. Some of the fish from the Fish Tissue Archive from the years 2007-2011 were analyzed for substances in current and proposed European legislation regarding environmental quality standards (EQS) in biota. It was found that mercury exceeded the EU EQS of 20 ?g/kg in 79% of samples with an average and median of 31 and 29 ?g/kg. The legacy fungicide hexachlorobenzene (HCB) was below the EQS of 10 ?g/kg in all fish analyzed, with a maximum of 6 ?g/kg in some eels. The legacy solvent hexachlorobutadiene (HCBD) was below the EQS of 55 ?g/kg, being <0.2 ?g/kg in all samples where it was measured. The sums of six polybrominated diphenyl ethers (PBDEs) were several orders of magnitude higher than the new proposed 0.0085 ?g/kg biota EQS. This study showed that the regular collection and analysis of whole body homogenate samples of relatively small native pelagic fish is suitable for the monitoring of contaminants capable of bioaccumulation. With regard to current or proposed EQS for EU countries, mercury and potentially PBDE in fish are of some concern in these English rivers. PMID:23747559
Jürgens, Monika D; Johnson, Andrew C; Jones, Kevin C; Hughes, David; Lawlor, Alan J
The use of Taqman real-time PCR-based technology has recently become more frequent in the detection of pathogens in the aquaculture industry. This interest has necessitated the development of robust and reliable pathogen-detection assays. The development of a range of endogenous control assays to be run alongside these diagnostic assays works to further increase confidence in the latter. This study describes the design of a range of endogenous control assays based on the elongation factor 1-? (EF1-?) gene specific to a range of fish species including Atlantic salmon, Salmo salar; rainbow trout, Oncorhynchus mykiss; brown trout, Salmo trutta; cod, Gadus morhua; haddock, Melanogrammus aeglefinus; saithe, Pollachius virens; whiting, Merlangius merlangus; Norway pout, Trisopterus esmarkii; carp (family Cyprinidae), roach, Rutilus rutilus; European eel, Anguilla anguilla; and herring, Clupea harengus, as well as a number of fish cell lines. Evidence is provided of the validation of these assays for specific species, a range of tissue types and cell lines as well as an example of the potential uses of these assays. PMID:22524565
Bland, F; McIntosh, R; Bain, N; Snow, M
1. Life-history omnivory or size-induced mixed competition-predation systems have under many conditions theoretically been shown to be fragile, whereas at the same time existing empirical data suggest such systems to be common in nature. 2. In a whole lake experiment covering 17 years, we analysed the effects of the introduction of the intraguild prey roach (Rutilus rutilus) on the population size and individual performance of the intraguild predator perch (Perca fluviatilis) and on resource levels in two low productivity systems. 3. A strong long-term effect of roach on the zooplankton resource but not on the macroinvertebrate resource was present. Competitive effects of roach on perch were observed in one of the lakes the first years after the introduction, but at the end of the study no competitive effect of roach on either size class of perch was observed in any of the two lakes. In contrast, a positive predatory effect reflected in improved growth rates of older perch was present. 4. The lack of a support for a competitive effect of roach on small perch raises the question of the importance of mixed competition-predation interactions in life-history omnivorous systems and the problem of comparing descriptive data on feeding relationships with theoretical predictions based on interaction modules. PMID:22081866
Persson, Lennart; De Roos, André M
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.
Nicolle, Alice; Hansson, Lars-Anders; Brodersen, Jakob; Nilsson, P. Anders; Bronmark, Christer
Migration has evolved as a strategy to maximise individual fitness in response to seasonally changing ecological and environmental conditions. However, migration can also incur costs, and quantifying these costs can provide important clues to the ultimate ecological forces that underpin migratory behaviour. A key emerging model to explain migration in many systems posits that migration is driven by seasonal changes to a predation/growth potential (p/g) trade-off that a wide range of animals face. In this study we assess a key assumption of this model for a common cyprinid partial migrant, the roach Rutilus rutilus, which migrates from shallow lakes to streams during winter. By sampling fish from stream and lake habitats in the autumn and spring and measuring their stomach fullness and diet composition, we tested if migrating roach pay a cost of reduced foraging when migrating. Resident fish had fuller stomachs containing more high quality prey items than migrant fish. Hence, we document a feeding cost to migration in roach, which adds additional support for the validity of the p/g model of migration in freshwater systems.
Chapman, Ben B.; Eriksen, Anders; Baktoft, Henrik; Brodersen, Jakob; Nilsson, P. Anders; Hulthen, Kaj; Bronmark, Christer; Hansson, Lars-Anders; Gr?nkjaer, Peter; Skov, Christian
Liver and gills of roach (Rutilus rutilus) and silver carp (Hypophthalmichthys molitrix) were examined for glutathione S-transferases (GSTs) contents and their substrate specificity and capacity to biotransform microcystin-LR (MC-LR). GSTs and other glutathione (GSH) affine proteins were purified using a GSH-agarose matrix and separated by anionic chromatography (AEC). Substrate specificities were determined photometrical for 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), 4-nitrobenzyl chloride (pNBC) and ethacrynic acid (ETHA). Biotransformation rate of MC-LR was determined by high performance liquid chromatography (HPLC). Roach exhibited different hepatic and branchial GST activities for used substrates (DNB, pNBC and DCNB) compared to silver carp but not for ethacrynic acid. It suggests that, both fish species have similar amount of pi and/or alpha class, which were the dominant GST classes in liver and gills. Gills of both fish species contained a higher number of GST isoenzymes, but with lower activities and ability of MC-LR biotransformation than livers. GST isoenzymes from roach had higher activity to biotransform MC-LR (conversion rate ranging up to 268 ng MC-LR min(-1) mL(-1) hepatic enzyme) than that isolated from silver carp. Without any prior contact to MC-LR or another GST inducer, roach seems to be better equipped for microcystin biotransformation than silver carp. PMID:19101655
Setlíková, I; Wiegand, C
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.
Litvinov, Alexander G.; O'Gorman, Robert
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.
Prigge, Enno; Malzahn, Arne M.; Zumholz, Karsten; Hanel, Reinhold
Globally, feminization responses in wild male freshwater fish are caused by exposure to estrogenic chemicals, including natural and synthetic estrogens, contained in effluentsfromwastewater treatment works. In U.K. rivers, feminization responses, including intersex, are widespread in wild roach (Rutilus rutilus) populations, and severely affected fish have a reduced reproductive success. We exposed roach to environmentally relevant concentrations of the contraceptive estrogen 17alpha-ethinylestradiol (EE2) for up to 2 years, including intermittent and repeated exposures,to determine effects on sexual development and subsequent responsiveness to estrogen. Exposure of roach to EE2 (at 4 ng/L) for 2 years resulted in sex reversal in males, leading to an all-female population with two cohorts in terms of their stages of ovarian development one paralleling the control females and one at a significantly less advanced stage, which we propose were sex-reversed males. Differing developmental and maturing rates of the putative sex-reversed males compared with control females would question their functional capability as females in the wild. Early-life exposure to environmentally relevant concentrations of EE2 sensitized females to estrogen, as determined by the measurement of the responses of estrogen-sensitive genes in a further EE2 challenge 398 days after the original exposure. In the wild, exposure to environmentally relevant concentrations of EE2 during early life has significantly wider implications for the sexual physiology in fish than has thus far been determined. PMID:19320183
Lange, Anke; Paull, Gregory C; Coe, Tobias S; Katsu, Yoshinao; Urushitani, Hiroshi; Iguchi, Taisen; Tyler, Charles R
Background The feminization of nature by endocrine-disrupting chemicals (EDCs) is a key environmental issue affecting both terrestrial and aquatic wildlife. A crucial and as yet unanswered question is whether EDCs have adverse impacts on the sustainability of wildlife populations. There is widespread concern that intersex fish are reproductively compromised, with potential population-level consequences. However, to date, only in vitro sperm quality data are available in support of this hypothesis. Objective The aim of this study was to examine whether wild endocrine-disrupted fish can compete successfully in a realistic breeding scenario. Methods In two competitive breeding experiments using wild roach (Rutilus rutilus), we used DNA microsatellites to assign parentage and thus determine reproductive success of the adults. Results In both studies, the majority of intersex fish were able to breed, albeit with varying degrees of success. In the first study, where most intersex fish were only mildly feminized, body length was the only factor correlated with reproductive success. In the second study, which included a higher number of more severely intersex fish, reproductive performance was negatively correlated with severity of intersex. The intersex condition reduced reproductive performance by up to 76% for the most feminized individuals in this study, demonstrating a significant adverse effect of intersex on reproductive performance. Conclusion Feminization of male fish is likely to be an important determinant of reproductive performance in rivers where there is a high prevalence of moderately to severely feminized males.
Harris, Catherine A.; Hamilton, Patrick B.; Runnalls, Tamsin J.; Vinciotti, Veronica; Henshaw, Alan; Hodgson, Dave; Coe, Tobias S.; Jobling, Susan; Tyler, Charles R.; Sumpter, John P.
The high incidence of intersex roach (Rutilus rutilus) in some United Kingdom rivers that has been associated with exposure to sewage treatment works (STWs) effluent led us to hypothesize that top predator fish also may be affected by estrogenic chemicals, because they are likely to bioaccumulate lipophilic compounds through a predator-prey relationship. To investigate this possibility, pike (Esox lucius) were sampled both upstream and downstream of STWs and then examined for total estrogenic activity of their bile, as measured using a yeast-based estrogen assay to determine the degree of recent exposure of the pike to estrogens and vitellogenin induction, and for possible disruption of sexual development, as measured using histological analysis of the gonads. No evidence of severe disruption was found in the sampled fish, which came from 16 sampling sites that were representative of English rivers. However, 14% of pike were intersex, of which 15 of 16 showed patches of male germ cells among predominantly female gonadal tissue. The incidence of masculinization was independent of whether the pike had been sampled upstream or downstream of STWs. Although pike are gonochoristic, it is not known if this masculinization of presumptive female pike is normal or, instead, indicative of endocrine disruption. Vitellogenin concentrations were not elevated in male pike at sites either upstream or downstream of STWs. The results suggest that sexual disruption is not common in pike, a fish at the top of the food chain in the freshwaters of England. PMID:16117120
Vine, Emma; Shears, Jan; van Aerle, Ronny; Tyler, Charles R; Sumpter, John P
Sampling of the fish community was carried out for 20 years in the Mirgenbach reservoir, in North-Eastern France. The prevalence and the mean intensity of Ligula intestinalis (Cestoda) were analysed in roach (Rutilus rutilus) and silver bream (Blicca bjoerkna) populations, the main two infected species. The aim of this study was to investigate the host switch from roach to silver bream and the consequences of L. intestinalis infestation in silver bream, which is an unusual host for this parasite as Ligula parasitism in silver bream appears to be rare. We analysed in detail the relationships between parasitism index (PI), gonadosomatic index (GSI), perivisceral fat abundance (PFA) and condition index (CI) in the silver bream population. In 1998, prevalence of L. intestinalis highlighted a clear host switch from roach to silver bream. In the silver bream population, young fish were the most severely infected and the impact of plerocercoids appeared to be different depending on the host sex. In male silver bream, plerocercoids drew energy from fat reserves even if GSI was also slightly impacted. On the contrary, in females energy was diverted from gonad maturation rather than from perivisceral fat reserves. No significant difference was observed in terms of CI in either sex. PMID:22217256
Vanacker, M; Masson, G; Beisel, J-N
In widespread species, northern taiga voles, most significant differences in the intensity of energy metabolism (M), maximum (Mmax) and reserve (Mres) metabolism were observed at winter temperatures (-5-20 degrees C): Clethrionomys rutilus greater than C. rufocanus greater than Microtus oeconomus; differences in seasonal increase of Mmax and Mres exhibit an inverse proportion. Seasonal changes in M and Mmax in autochthonous tundra rodents indicate that Lemmus sibiricus belongs to a more eurybiont species as compared to Dicrostonyx torquatus. The main characteristic feature of seasonal adaptation of M in lemmings, as compared to voles, is the evident decrease of M value in winter which is accompanied by a more significant increase of Mmax and Mres. Operative pattern and high seasonal mobility of chemical thermoregulation in lemmings are suggested which account for adaptation of these animals mainly to short-term extreme effects of low temperatures. PMID:2596207
Pastukhov, Iu F; Belogubova, E G
Mercury (Hg) concentrations in burbot (Lota lota), perch (Perca fluviatilis), northern pike (Esox lucius), roach (Rutilus rutilus), whitefish (Coregonus lavaretus) and peled (C. peled) were monitored in 18 reservoirs situated in western and northern Finland over a period of 16 years (1979-1994). The reservoirs were impounded from 1964 to 1980. The surface areas ranged between 1 and 417 km2. Data from downstream sites and reference lakes were compared to reservoir mercury data. Generally, fish Hg concentrations in reservoirs exceeded those in natural lakes. Shortly after inundation, fish mercury concentrations clearly increased and remain 15-25 years above background concentrations. The mean Hg concentrations in standardized 1 kg pike from 1989 to 1993 was 0.45 mg/kg in natural lakes and 0.58 mg/kg in reservoirs. The 1 mg/kg fish Hg level recommended by health authorities as the upper limit for human consumption was still exceeded in two reservoirs 20 years old or more. The two largest reservoirs (24 and 27 years old in 1994) with significant commercial fishing had Hg levels below 0.5 mg/kg in all fish species studied. Statistical models for predicting the Hg concentrations in the weight standardized pike were verified with the observed data. For most of the reservoirs, predictions from models based on pH, organic matter (COD) in water, the extent of water level regulation and reservoir age agreed well with observed data. In the most southern, new (under 20 years old) and heavily regulated reservoirs, pike Hg concentration followed a logarithmic function of reservoir age. Model predictions of mercury in pike in the planned Vuotos reservoir (in northern Finland) predicted that Hg would exceed 1 mg/kg Hg for the first 12 years after the flooding. PMID:9652133
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 (2-5 °C) 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 (+2 °C) 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
Brodersen, Jakob; Rodriguez-Gil, José Luis; Jönsson, Mikael; Hansson, Lars-Anders; Brönmark, Christer; Nilsson, P Anders; Nicolle, Alice; Berglund, Olof
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
Mikheev, V N; Mikheev, A V; Pasternak, A F; Valtonen, E T
UV filters are widely used compounds in many personal care products and cosmetics, such as sunscreens. After use, UV filters are washed off from skin and clothes and enter the aquatic environment. Recent studies indicate that some lipophilic UV filters do accumulate in biota and act as endocrine disruptors. In this study, concentrations of 4-MBC (4-methylbenzylidene camphor) and OC (octocrylene), two widely used UV filters, were determined in the muscle tissue of fish (brown trout, Salmo trutta fario) from seven small Swiss rivers, all receiving inputs from wastewater treatment plants (WWTPs). Lipid-weight based concentrations of up to 1800 (4-MBC) and 2400 ng g(-1) (OC) were found. These levels were distinctly higher than those previously observed in white fish (Coregonus sp.) and roach (Rutilus rutilus) from Swiss lakes with inputs from WWTPs. This suggests a higher availability of these contaminants for fish in rivers than in lakes and identifies WWTPs as a major source for UV filters in the aquatic environment. As compared to lake fish, individual fish from a river showed much greater variation in 4-MBC and OC concentrations, likely as a result of a wider range of exposure in rivers than in lakes. 4-MBC concentrations correlated reasonably well with concentrations of methyl triclosan, a chemical marker for lipophilic WWTP-derived contaminants. The ratio P/Q of population (P) in a watershed to water throughflow (Q) is considered to be a measure of the domestic burden from WWTPs. A correlation of methyl triclosan with P/Q was previously observed with lake fish. However, such a correlation could not be confirmed with river fish. The higher average concentrations of OC as compared to 4-MBC in river fish, and the fact that OC was mostly absent in lake fish, suggests differences in bioaccumulation and availability of these two UV filters. PMID:16568752
Buser, Hans-Rudolf; Balmer, Marianne E; Schmid, Peter; Kohler, Martin
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 or 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.
French, John R. P., III
Seven "target" PCB levels were determined and compared in waterbird eggs, in their prey, and in water at Lake Kerkini, northern Greece, to investigate PCB bioaccumulation patterns and to define the best bioindicator of target PCBs for this area. PCBs were analysed from eggs of Phalacrocorax carbo, Podiceps cristatus, Ardea cinerea, Egretta garzetta, and Nycticorax nycticorax and from prey types Alburnus alburnus, Rutilus rutilus, Lepomis gibbosus. Carassius auratus, and Rana sp. PCBs analysed were detected in all bird eggs, prey, and water but contamination patterns differed among these sample types. The lipid-corrected geometric means of the congeners analysed were significantly different among most bird species and among some prey species. PCB congeners 118, 138, 153, and 180 accounted for around 80% of the total PCB contamination in bird egg samples. Percent congener concentrations of high-chlorinated PCBs tended to increase from water through prey to most bird egg samples whereas the low chlorinated PCBs (28 and 52) decreased. Bioaccumulation factors (BAFs) also exhibited an increasing trend for higher chlorinated PCBs from prey types to bird eggs. The greatest BAFs of six of the congeners were shared between Phalacrocorax carbo and Ardea cinerea. Among prey, the BAFs of four PCBs were highest in Lepomis gibbosus. Biomagnification factors varied between 1.01 and 39.57. In contrast to low chlorinated PCBs, high chlorinated congeners biomagnified considerably through fish prey. The highest biomagnification took place in Phalacrocorax carbo. No relationship was found between the lipid content of samples and BAFs of PCBs probably due to biotransformation differences of the congeners in the biota sampled. Due to the greatest PCB concentrations especially of the higher chlorinated PCBs in the eggs of Phalacrocorax carbo and its considerable bioaccumulation tendencies, it is proposed as the best PCB biomonitor of target PCBs at Lake Kerkini. Lepomis gibbosus had the highest concentrations of most congeners and exhibited the greatest bioaccumulative properties among prey and can be used as an alternative biomonitor. PMID:17549546
Antoniadou, V; Konstantinou, I K; Goutner, V; Sakellarides, T M; Albanis, T A; Bintoudi, E
Mercury (Hg) is a highly toxic metal posing a hazard to water ecosystems. This investigation was aimed at determining Hg content in the Tanew River, Poland, and subsequent transfer to fish inhabiting this lake. The area studied included approximately a 50-km distance of the river, with 5 sampling locations selected. Samples of water and bottom sediments were collected from 10 sites along the river-bank zone for each location. At the same location, fish were caught and samples of coastal water plants were collected. Fish that were caught included the following species: chub (Leuciscus cephalus), pike (Esox lucius), ide (Leuciscus idus), and roach (Rutilus rutilus). Dominanting species of water plants included reed-mace (Typha angustifolia), rigid hornwort (Ceratophyllum demersum), and water knotweed (Polygonum amphibium). Mercury content in samples of water, bottom sediments, water plants, and fish tissues (muscles and gills) were determined by using a Mercury/MA-2000 system (NIC, Japan). The average Hg content in the waters of Tanew ranged between 1 and 5 microg/L, and in the bottom sediments ranged between 17 and 214 microg/kg dry weight, which are characteristic values for typical unpolluted areas. The highest Hg contamination of waters and bottom sediments was found where the Tanew estuary enters the San River. Mercury levels in fish from the Tanew delta appeared to be higher compared to other sampling sites. Data indicated that even if water environment is contaminated with Hg to a limited extent, fish accumulate this metal at higher levels, probably due to a bioaccumulation or bioconcentration factor. PMID:20706942
Wa?kuska, Grazyna; Cha?abis-Mazurek, Agnieszka; Szkoda, Józef
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.
Liney, Katherine E.; Hagger, Josephine A.; Tyler, Charles R.; Depledge, Michael H.; Galloway, Tamara S.; Jobling, Susan
To establish whether the intersex condition seen in the roach (Rutilus rutilus) in United Kingdom (UK) rivers was species specific or a more general phenomenon in fish, evidence for sexual disruption was sought in a second cyprinid species, the gudgeon (Gobio gobio). Gudgeon were collected from the Rivers Aire and Lea (at locations that receive high-volume discharges of sewage treatment works [STW] effluent and that contain intersex roach) and from two still waters, and their gonads were examined histologically for evidence of intersexuality (the simultaneous presence of oocytes and testicular tissue). Intersex gonads were found at all sites, with the highest incidences occurring at one of the still waters (Lakeside Fisheries: 15%) and at sites on the River Aire (Thwaite Weir, Silsden Bridge, and Knostrop: 14, 13, and 12%, respectively). In the River Lea and Longton Park Lake, the incidence of intersexuality in gudgeon was 6%. In most cases, intersex gonads were characterized by a few primary oocytes/gonad section in an otherwise normal testis. However, at some sites on the River Aire (Thwaite Weir and Knostrop), the intersex condition was more severe. At Thwaite Weir, for example, more than half of the gonad in 40% of the intersex fish was comprised of ovarian tissue. Elevated concentrations of plasma vitellogenin both in male and in intersex fish indicated that fish had been exposed to estrogen(s). Some of the gudgeon were found at sites several kilometers downstream of any point discharge of STW effluent; therefore, the results likely are representative of this species in wild populations found in typical UK river ecosystems. Together with the findings in the roach, these data on the gudgeon confirm that sexual disruption in fish in UK rivers is not species specific. PMID:11764169
van Aerle, R; Nolan, T M; Jobling, S; Christiansen, L B; Sumpter, J P; Tyler, C R
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 Zemplínska šírava (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
Brázová, Tímea; Hanzelová, Vladimíra; Miklisová, Dana; Šalgovi?ová, Danka; Tur?eková, L'udmila
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. PMID:10464075
Tuvikene, A; Huuskonen, S; Koponen, K; Ritola, O; Mauer, U; Lindström-Seppä, P
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
Tuvikene, A; Huuskonen, S; Koponen, K; Ritola, O; Mauer, U; Lindstrom-Seppa, P
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.
Sonnenberg, Rainer; Nolte, Arne W; Tautz, Diethard
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 [17beta-estradiol (E2), estrone (E1), and 17alpha-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
Jobling, Susan; Williams, Richard; Johnson, Andrew; Taylor, Ayesha; Gross-Sorokin, Melanie; Nolan, Monique; Tyler, Charles R; van Aerle, Ronny; Santos, Eduarda; Brighty, Geoff
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 [17? -estradiol (E2), estrone (E1), and 17? -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.
Jobling, Susan; Williams, Richard; Johnson, Andrew; Taylor, Ayesha; Gross-Sorokin, Melanie; Nolan, Monique; Tyler, Charles R.; van Aerle, Ronny; Santos, Eduarda; Brighty, Geoff
Ixodes trianguliceps is a common tick species of the Eurasian forest zone. These ticks live probably in natural foci of ixodid tick-borne borrelioses (ITBB) from Western Europe to Transbaikalia, but their role in circulation of corresponding pathogens remains unclear. This study was performed in a natural ITBB focus located in the Perm region of Russia (near the Urals), where Borrelia garinii and B. afzelii circulate and I. persulcatus serves as their main vector. In July-August of 1994, 296 small mammals (mostly Clethrionomys glareolus) were tested for tick infestation. From these mammals, 49 I. trianguliceps and 252 I. persulcatus ticks were collected (16.3 and 83.7%, respectively). I. trianguliceps ticks were found on 33 rodents of three species: Cl. glareolus, Cl. rutilus, and Microtus oeconomus. The abundance of I. trianguliceps (on average, less than 0.2 ticks per animal) was approximately five times lower than that of I. persulcatus. I. trianguliceps larvae, nymphs, and adults (22, 15, and 5 specimens, respectively) were analyzed for Borrelia infection by plating their internal organs on the BSK-2 medium. Spirochete isolates were obtained from four nymphs. Three infected nymphs were collected from different Cl. glareolus specimens, and one was found on Cl. rutilus. According to the results of RFLP analysis, all four isolates were classified as B. garinii. This experiment is the first successful attempt to isolate one of ITBB pathogens from I. trianguliceps ticks. These ticks do not attack people, and their role in ITBB foci should be analyzed only in terms of epizootiology. The results of previous zoological-parasitological and bacteriological studies performed in the Ural region suggest that I. trianguliceps and I. persulcatus populations are maintained there by the same species of small rodents and insectivores, which mostly belong to the genera. Clethrionomys and Sorex. Many of them were identified as the reservoir hosts of Borrelia. These data, in complex with the fact of B. garinii isolation from I. trianguliceps, suggest that I. trianguliceps ticks are involved in the maintenance of Borrelia circulation in natural ITBB foci. Taking into account the low abundance of these ticks in the Ural forests, they should be regarded as an important but not principal component of the epizootic process. It is suggested that such a conclusion about the significance of I. trianguliceps ticks also pertains to ITBB foci of other regions. PMID:8975209
Gorelova, N B; Korenberg, E I; Kovalevski?, Iu V; Postic, D; Baranton, G
Leuciscine fishes represent an important component of freshwater ichthyofauna endemic to northern Mediterranean areas. This lineage shows high intra-specific morphological variability and exhibits high levels of hybridization, two characteristics that contribute to systematic uncertainties, misclassification of taxa and, potentially, the mismanagement of biodiversity. This study focused on brook chub, Squalius lucumonis, an endemic taxon of Central Italy. The taxonomic status of this species has long been questioned, and a hybrid origin from sympatric leusciscines (S. squalus x Rutilus rubilio, or S. squalus x Telestes muticellus) has been hypothesised. A phenotypic (evaluating shape and meristic counts) and genetic (using mitochondrial and nuclear markers) investigation of these four taxa was conducted to test species delimitation in sympatric areas and to evaluate the taxonomic status of S. lucumonis. One hundred and forty-five individuals of all four taxa were collected within streams of the lowest portion of the Tiber River basin and analysed; this region encompasses a large portion of the S. lucumonis distribution. The different morphological and genetic approaches were individually examined, compared, and then combined in a quantitative model to both investigate the limits of each approach and to identify cases of misclassification. The results obtained confirm the cladogenetic non-hybrid origin of S. lucumonis, highlight the need for immediate conservation actions and emphasise the value of an integrated approach in the study of leuciscines evolution.
Tancioni, Lorenzo; Russo, Tommaso; Cataudella, Stefano; Milana, Valentina; Hett, Anne Kathrin; Corsi, Elisa; Rossi, Anna Rita
Human Alveolar Echinococcosis (HAE) is a potentially fatal parasitic disease caused by Echinococcus multilocularis, a cestode characterized by a sylvatic life-cycle involving several species of rodents and lagomorphs as intermediate hosts and canids as definitive hosts. Despite the wide distribution of the parasite in North America, the number of competent intermediate host species identified to date is still relatively small, and mainly includes the northern vole (Microtus oeconomus), brown lemming (Lemmus sibiricus), northern red-backed vole (Myodes rutilus), deer mouse (Peromyscus maniculatus) and meadow vole (Microtus pennsylvanicus). By monitoring the infections in rodents in the city of Calgary (Alberta, Canada), we have detected a case of severe alveolar echinococcosis in a southern red-backed vole (Myodes gapperi), a species never reported before as an intermediate host for this parasite. Observation of protoscolices in the intra-abdominal multilocular cysts indicates that M. gapperi could act as a competent intermediate host for the transmission of E. multilocularis. Since M. gapperi can be found in close proximity to, and within metropolitan areas, this species could play a role in the establishment and maintenance of the sylvatic life-cycle of E. multilocularis in urban landscapes, where the potential for zoonotic transmission is higher. The new intermediate host reported needs to be taken into account in future surveys and transmission models for this parasite. PMID:23608104
Liccioli, Stefano; Duignan, Pádraig J; Lejeune, Manigandan; Deunk, Joanna; Majid, Sultana; Massolo, Alessandro
In this study, concentrations of zinc, chromium, cadmium and lead were determined in water and three species of fish sampled from 10 selected stations along Gorgan coast using atomic absorption spectrophotometery, summer 2009. Mean lead levels in water and fish samples (119.50 ± 22.24 ?g/L and 113.80 ± 33.11 ?g/kg) were significantly higher than that of cadmium and chromium (p < 0.05). Cyprinus carpio had highest metals content than Mugila auratus and Rutilus frisikutum. The evaluated metals values in water collected from Gomishan wetland (Pb, Cd, Cr and Zn values are 145.31 ± 35.32, 120.46 ± 11.44, 96.47 ± 6.05 and 82.02 ± 34.37 ?g/L, respectively) were higher than the other sampling sites. The result is consistent with the findings accessed by evaluation of the metals in fish specimens. The metals concentrations in the fish and water samples were below the recommended limits. But, elevating levels of metals in water and fish made a serious concern about ecosystem and food chain contamination. PMID:22664555
Saeedi Saravi, S S; Karami, B; Karami, S; Shokrzadeh, M
A comparative study of seasonal-age dynamics of brain size in six small mammal species, Clethrionomys glareolus, C. rutilus, Microtus oeconomus, M. gregalis (Rodentia); Sorex araneus, S. minutis (Insectivora) has been carried out. The analysis of seasonal changes in brain weight confirms the existence of autumn-winter regression of brain weight, which takes place at the organism level. The regression is less pronounced in voles than in shrews. The decrease in brain weight both in voles and in shrews is accompanied by the decrease in height (capacity) of brain capsule of cranium. In spring the brain weight increase and reaches its maximal specific values in wintered voles in summer. In wintered shrews the brain weight never reaches the value, inherent in young animals before winter regression. The analysis of the data obtained and published data on variability of craniometric features allowed to conclude that seasonal changes in brain size, accompanied by the changes in capacity of cranium capsule might be considered as a general pattern for a large group of palearctic and nonarctic species of small mammals. PMID:2800709
Iaskin, V A
The structural and functional organization and the spatio-temporal interrelations of three sympatric vole species (Microtus oeconomus, Clethrionomys, rutilus, and C. rufocanus) were analyzed on territories different in the type of their functional significance to the animals (survival stations, zones of temporary dispersal, and transit zones). The study was conducted in the environs of the Iremel massif (54 degrees 31'25" N 58 degrees 50'18" E) in 1979-1981, in four 1 ha marking-areas in four different altitudinal zones. It is shown that the abundance and demographic structure is different for each species pair in each area, whereas their dynamics in synchronous. The overlap of niches in two Clethrionomys species is small and cannot cause their competition for food. The distribution of voles within the areas is usually independent, but has some peculiarities depending on the type of territory usage by the animals. Preferred microterritories that help species to avoid competition are revealed for each species to occur in different areas. These are cases of spatial separation, not of ecological isolation of sympatric species. Spatial and temporal division of environmental resources is controlled by mechanisms that have developed in the process of the community's evolution. PMID:18257290
Zhigal'ski?, O A
Pairing of X and Y chromosomes at meiotic prophase in 14 species of the subfamily Microtinae (Clethrionomys rufocanus, C. rutilus, C. glareolus, Arvicola terrestris, Microtus guentheri, M. socialis, M. afghanus, M. bucharicus, M. oeconomus, M. arvalis, M. rossiaemeridionalis, M. kirgisorum, M. transcaspicus, M. (Pitymys) majori) was analysed in relation to their taxonomic position and variation in the morphology of their sex chromosomes. The sex chromosomes formed a synaptonemal complex (SC) at pachytene in all Clethrionomys species, Arvicola terrestris, and M. oeconomus, while they did not pair at all in M. (Pitymys) majori, Microtus socialis, M. guentheri, M. afghanus, M. bucharicus, M. arvalis, M. rossiaemeridionalis, M. kirgisorum, and M. transcaspicus. The X chromosome of these species varied in centromere position independently of pairing pattern. Insertion of heterochromatin of different size and location was found in some, but not in all species with asynaptic sex chromosomes. It is suggested that the sex chromosomes lost their ability to pair at male meiosis in the common ancestor of palearctic species of the genus Microtus. This event was not caused by a gross chromosomal rearrangement. PMID:8598341
Borodin, P M; Sablina, O V; Rodionova, M I
The terrestrial mammalian fauna of the North Japanese island, Hokkaido, is more similar to that of Southern Siberia than to the main island of Japan, Honshu. Three species of the genus Myodes (Muridae, Rodentia) are found on Hokkaido, but not on Honshu. While Myodes rufocanus and M. rutilus are widely distributed across Hokkaido as well as the Eurasian continent, M. rex, which is endemic to Hokkaido and its adjacent islands, shows a discontinuous distribution pattern. We analyzed the phylogeographic history of M. rex using the mitochondrial DNA control region in order to interpret their discontinuous distribution pattern. Phylogenetic relationships among 54 distinct haplotypes showed that M. rex can be divided into four clades that occur on the northern, central, and southern regions of the Hokkaido mainland and on Rishiri Island, respectively. The phylogroups in the northern and central regions were largely separated in space, although several areas of sympatry were found. The phylogroup in the southern region, which was clearly separated from other phylogroups, showed markedly low genetic variability. All analyzed individuals from the population on Rishiri belonged to a separate lineage. Across a range of divergence rate estimates, we dated the basal divergence of all phylogroups to the mid to late Pleistocene, with subsequent signals of population expansion within lineages. We conclude that current phylogeographic structure in M. rex likely reflects Pleistocene survival in several separate refugia in situ. Past glacial ages have thus played an important role in shaping the current distribution patterns of mammalian species on Hokkaido. PMID:23915157
Kawai, Kuniko; Hailer, Frank; de Guia, Anna Pauline; Ichikawa, Hideo; Saitoh, Takashi
Organic UV filters are used in personal care products such as sunscreen products, and in cosmetics, beauty creams, skin lotions, lipsticks, hair sprays, hair dyes, shampoos, and so forth. The compounds enter the aquatic environmentfrom showering, wash-off, washing (laundering), and so forth via wastewater treatment plants (WWTPs) ("indirect inputs") and from recreational activities such as swimming and bathing in lakes and rivers ("direct inputs"). In this study, we investigated the occurrence of four important organic UV filter compounds (benzophenone-3, BP-3; 4-methylbenzylidene camphor, 4-MBC; ethylhexyl methoxy cinnamate, EHMC; octocrylene, OC) in wastewater, and in water and fish from various Swiss lakes, using gas chromatographic/mass spectrometric analyses. All four UV filters were present in untreated wastewater (WWTP influent) with a maximum concentration of 19 microg L(-1) for EHMC. The data indicate a seasonal variation with influent loads higher in the warmer season (June 2002) than in the colder one (April 2002). The influent loads were in the order EHMC > 4-MBC approximately BP-3 > OC. The concentrations in treated wastewater (WWTP effluent) were considerably lower, indicating substantial elimination in the plants. 4-MBC was usually the most prevalent compound (maximum concentration, 2.7 microg L(-1)), followed by BP-3, EHMC, and OC. UV filters were also detected in Swiss midland lakes and a river (Limmat) receiving inputs from WWTPs and recreational activities. However, all concentrations were low (<2-35 ng L(-1)); no UV filters (<2 ng L(-1)) were detected in a remote mountain lake. Data from passive sampling using semipermeable membrane devices (SPMDs) supported the presence of these UV filters in the lakes and the river and suggested some potential for accumulation of these compounds in biota. SPMD-derived water concentrations increased in the order Greifensee < Zürichsee < Hüttnersee. This order is reversed from that observed for methyl triclosan, used as a chemical marker for WWTP-derived lipophilic contaminants in the lakes. This indicated inputs of UV filters from sources other than WWTPs to the lakes during summer,for example,inputs from recreational activities. Fish (white fish, Coregonus sp.; roach, Rutilus rutilus; perch, Perca fluviatilis) from these lakes contained low but detectable concentrations of UV filters, in particular, 4-MBC (up to 166 ng g(-1) on a lipid basis). 4-MBC concentrations relative to methyl triclosan were lower in fish than in SPMDs exposed in the same lakes, suggesting that 4-MBC is less bioaccumulated than expected or metabolized in fish. The lipid-based bioconcentration factor (BCF(L)) estimated from the fish (roach) data and SPMD-derived water concentrations was about 1-2.3 x 10(4) and thus approximately 1 order of magnitude lower than expected from its Kow value. PMID:15773466
Balmer, Marianne E; Buser, Hans-Rudolf; Müller, Markus D; Poiger, Thomas
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
Graham, C T; Harrod, C
Most effluents from wastewater treatment works (WwTWs) contain estrogenic chemicals that include steroidal estrogens and xenoestrogens. We investigated the nature of mixtures of estrogenic contaminants taken up by two species of fish exposed to two WwTWs effluents. Sexually immature rainbow trout, Oncorhynchus mykiss, and sexually mature roach, Rutilus rutilus, were exposed to tap water, river water, or one of two estrogenic WwTWs effluents for up to 10 days, when the fish were sacrificed and tissues removed for chemical analysis. Estrogenic contaminants in the bile and gonads were hydrolyzed, concentrated by solid-phase extraction, and fractionated by RP-HPLC. Active fractions were detected and quantified using a yeast estrogen receptor transcription screen (YES assay) and the identities of estrogenic components in the fractions determined by GC-MS. Bile from rainbow trout exposed to either tap water or river water contained low amounts of 17beta-estradiol (E2) and estrone (E1) with a total estrogenic activity (mean+/-standard error) of 10+/-5 and 31+/-9 ng of E2 equivalents/mL (ng of E2eq/mL) for male and female fish, respectively. In effluent-exposed trout the total estrogen content of bile was considerably higher with the following composition and concentrations (ng of E2eq/mL) of individual estrogens: E2 (male, 591+/-125; female, 710+/-207), E1 (male, 338+/-75; female, 469+/-164), ethinylestradiol, EE2 (male, 32+/-2; female, 40+/-6), nonylphenol (NP) and short-chain NP polyethoxylates (male, 21+/-4; female, 22+/-3). An additional estrogenic compound, 17beta-dihydroequilenin (DHQ), was identified for the first time in effluent-exposed fish, and was present in trout bile at concentrations of (male) 40+/-9 and (female) 30+/-5 ng of E2 eq/mL. DHQ, E2, E1, and EE2, but not NP or NP polyethoxylates, were also detected in bile of effluent-exposed roach, and the concentrations of all these steroidal estrogens in ng of E2eq/mL were lower in male (E2, 62+/-2; E1, 35+/-11; EE2, 10+/-2; DHQ, 1+/-1) compared with female (E2, 740+/-197; E1, 197+/-37; EE2, 40+/-6; DHQ, 8+/-2) roach. The synthetic estrogen EE2 was also detected in the testes and ovaries of effluent-exposed roach. This study shows that a mixture of estrogenic contaminants present in WwTWs effluents bioconcentrate in fish tissues, resulting in the induction of vitellogenin, and are likely to contribute to feminizing effects in wild fish living in U.K. rivers. The composition of the mixture of estrogenic contaminants in the bile is species dependent and may determine the susceptibility of fish to the effects of exposure to estrogenic effluents. PMID:15884336
Gibson, R; Smith, M D; Spary, C J; Tyler, C R; Hill, E M
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.
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
Fenlon, Kate A; Johnson, Andrew C; Tyler, Charles R; Hill, Elizabeth M
Disruption of the endocrine system has been shown to occur in wild freshwater fish populations across the globe. Effects range from subtle changes in the physiology and sexual behaviour of fish to permanently altered sexual differentiation, impairment of gonad development and/or altered fertility. A wide variety of adverse environmental conditions may induce endocrine disruption, including sub-optimal temperatures, restricted food supply, low pH, environmental pollutants, and/or parasites. Furthermore, it is conceivable that any/all of these factors could act simultaneously to cause a range of disparate or inter-related effects. Some of the strongest evidence for a link between an adverse health effect, as a consequence of endocrine disruption, and a causative agent(s) is between the condition of intersex in wild roach (Rutlius rutilus) in UK rivers and exposure to effluents from sewage treatment works. The evidence to indicate that intersex in roach (and other cyprinid fish living in these rivers) is caused by chemicals that mimic and/or disrupt hormone function/balance in treated sewage effluent is substantial. There are a few parasites that affect the endocrine system directly in fish, including the tape worm Ligula intestinalis and a few parasites from the micropsora phylum. L. intestinalis acts at the level of the hypothalamus restricting GnRH secretion (resulting in poorly developed gonads) and is one of the very few examples where an endocrine disrupting event has been shown to result in a population-level effect (reducing it). It is well established that many parasites affect the immune system and thus the most common effect of parasites on the endocrine system in fish is likely to be an indirect one. PMID:14667177
Jobling, S; Tyler, C R
Orthopoxviruses are being increasingly used as live recombinant vectors for vaccination against numerous infectious diseases in humans, domestic animals, and wildlife. For risk assessments and surveillance, information about the occurrence, distribution and ecology of orthopoxviruses in western Europe is important but has mainly been based on serological investigations. We have examined kidneys, lungs, spleens, and livers of Norwegian small rodents and common shrews (Sorex araneus) for the presence of orthopoxvirus DNA sequences by PCR with primers complementary to the viral thymidine kinase (TK) gene. PCR amplicons were verified as orthopoxvirus specific by hybridization with a vaccinia virus TK-specific probe. A total of 347 animals (1,388 organs) from eight locations in different parts of Norway, collected at different times of the year during 1993 to 1995, were examined. Fifty-two animals (15%) from five locations, up to 1,600 km apart, carried orthopoxvirus DNA in one or more of their organs, most frequently in the lungs. These included 9 of 68 (13%) bank voles (Clethrionomys glareolus), 4 of 13 (31%) gray-sided voles (Clethrionomys rufocanus), 3 of 11 (27%) northern red-backed voles (Clethrionomys rutilus), 16 of 76 (21%) wood mice (Apodemus sylvaticus), and 20 of 157 (13%) common shrews. The previous isolation of cowpox virus from two clinical cases of infection (human and feline) at two of the locations investigated suggests that the viruses detected are cowpox and that some of the virus-carrying small mammalian species should be included among the cowpox virus natural reservoir hosts in Scandinavia and western Europe.
Sandvik, Tore; Tryland, Morten; Hansen, Hilde; Mehl, Reidar; Moens, Ugo; Olsvik, ?rjan; Traavik, Terje
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.
Nine species of mosquitoes and several species of non-target aquatic organisms were tested for susceptibility to the mernaithid nematode, Strelkovimermis spiculatus. All species of Anopheles, Aedes, Culex, and Toxorhynchites exposed to S. spiculatus were susceptible. Of the nine mosquito species tested, C. pipiens quinquefasciatus had the greatest tolerance to initial invasion and the highest percent infection of those that survived. High levels of infection were also achieved with Aedes taeniorhynchus and A. albopictus, but these mosquitoes were significantly less tolerant to parasitism than C. pipiens quinquefasciatus. Strelkovimermis spiculatus did not infect or develop in any of the non-target hosts tested. PMID:19274233
Becnel, J J; Johnson, M A
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.
Johnston's sensory organ at the base of the antenna serves as a movement sound detector in male mosquitoes, sensing antennal vibrations induced by the flight sounds of conspecific females. Simultaneous examination of acoustically elicited antennal vibrations and neural responses in the mosquito species Toxorhynchites brevipalpis has now demonstrated the exquisite acoustic and mechanical sensitivity of Johnston's organ in males and, surprisingly, also in females. The female Johnston's organ is less sensitive than that of males. Yet it responds to antennal deflections of +/- 0.0005 degrees induced by +/- 11 nm air particle displacements in the sound field, thereby surpassing the other insect movement sound detectors in sensitivity. These findings strongly suggest that the reception of sounds plays a crucial role in the sensory ecology of both mosquito sexes. PMID:10737401
Göpfert, M C; Robert, D
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.
STALEY, MOLLY; DORMAN, KARIN S.; BARTHOLOMAY, LYRIC C.; FERNANDEZ-SALAS, ILDEFONSO; FARFAN-ALE, JOSE A.; LORONO-PINO, MARIA A.; GARCIA-REJON, JULIAN E.; IBARRA-JUAREZ, LUIS
The seasonal prevalence and container preferences of Aedes albopictus (Skuse) were studied in the park, Parque Mirador del Norte in Santo Domingo City, Dominican Republic, from January to December 1994. Tire ovitraps were set along a transect through the park and monitored weekly while two larval surveys were conducted in both the park and surrounding houses using standard entomological methodology. No seasonal pattern of oviposition was observed with similar numbers of positive tire traps collected in the wet and dry season. Most of the positive ovitraps were located in the middle of the park. Within ovitraps, Aedes aegypti (L.), Ae. albopictus, Culex corniger (Theobald), Ochlerotatus albonotatus (Coquillett), and Toxorhynchites sp. were collected. The larval surveys found 7 associated mosquito species, including Ae. aegypti, Ae. albopictus, Ochleotatus mediovittatus (Coquillett), Anopheles albimanus (Weidemann), Culex nigripalpus (Theobald), and Culex quinquefasciatus Say. The Ae. albopictus breeding sites were plastic buckets (4), rock holes (3), and Styrofoam lunch containers (3). We suggest that further studies should be conducted to determine its geographic distribution and vector potential in the Dominican Republic. PMID:14714670
Pena, Carlos J; Gonzalvez, Guillermo; Chadee, Dave D
Seventeen strains of mosquitoes belonging to 12 species in the Aedes scutellaris subgroup were tested for an ability to transmit one or more dengue virus serotype(s) vertically. Strains of virus employed for dengue types 1, 2, 3, and 4 were from Fiji, Bangkok, Burma, and Medan, respectively. After parental females were infected by intrathoracic inoculation, F1 larval and pupal progeny were tested for the presence of virus by inoculating aliquots of triturated suspensions into Toxorhynchites amboinensis mosquitoes. Dengue type 1 was transmitted vertically by 11 strains of mosquitoes representing 8 species with the highest filial infection rates observed for Ae. cooki (1.2%). Vertical transmission of the other dengue virus serotypes was observed for fewer species of mosquitoes, however the filial infection rates of those demonstrating vertical transmission were between 1%-2% for types 2 and 3, and about 0.5% for type 4. Tests with the progeny of individual Ae. cooki and Ae. polynesiensis infected with dengue virus types 1 and 3, respectively, showed that approximately greater than or equal to 50% of the parental females transmitted virus to their progeny. Highest filial infection rates were 6.7% for Ae. cooki and 4.6% for Ae. polynesiensis. PMID:3688318
Freier, J E; Rosen, L
Testing large numbers of specimens for viral antigens, antibodies, requires a great deal of manpower, time and money. Therefore it would be useful if testing could be performed with the specimens pooled. However, how to establish the optimal number of specimens to be pooled to achieve the maximum efficiency while maintaining both sensitivity and specificity is a question that needs to be answered. In this study, we developed a mathematical model and procedure to resolve this problem. We estimated a saving rate of over 98% for an assumed infection rate of 1/10000 by testing the sample in pools of 100-101 specimens. The saving rate decreases with increasing infection rates, until there is probably no efficiency gain achieved for infection rates greater than 30%. Tests of infection in pooled mosquitoes were assumed to be free of viruses other than the dengue virus to interfere with detection. Heads of Aedes mosquitoes were first pooled and squashed, and the extract obtained was injected by intrathoracic inoculation into Toxorhynchites amboinensis, a biological amplifier of dengue antigen. Sensitivity was not reduced. Therefore, this pooling technique is useful for determining the optimal number of specimens in a pool, calculating an exact infection rate, and for identifying specific infected specimens in tests of a large number of samples showing low rates of infection in our theoretical example. PMID:2005671
Ko, Y C; Lan, S J; Yen, Y Y; Chen, W J
The screening of 10 plant species (Aloe barbadensis Mill., Asparagus officinalis L., As. plumosus Bak., As. racemosus Willd., As. sprengeri Regel, Codyline fruticosa Goppert, Dracaena loureiri Gagnep., Gloriosa superba L., Hemerocallis flava L., and Sansevieria cylindrica Bojer) for colchicine-like substance(s) using a mosquito cytogenetic assay revealed that a 1% solution of dried Gl. superba rhizome extracted in 0.85% sodium chloride solution could be used instead of a 1% colchicine in Hanks' balanced salt solution. The metaphase rates and average number of metaphase chromosomes per positive mosquito of Aedes aegypti (L.) after intrathoracic inoculation with 1% Gl. superba-extracted solution were 100% and 29.80 in females, and 90% and 25.78 in males, whereas the inoculation with 1% colchicine solution yielded 100 and 90% metaphase rates, and 20.90 and 12.22 average number of metaphase chromosomes per positive mosquito in females and males, respectively. The application of Gl. superba-extracted solution for metaphase chromosome preparation in other mosquito genera and species [e.g., Culex quinquefasciatus Say, Toxorhynchites splendens (Wiedemann), and Anopheles vagus (Döenitz)] also has yielded the satisfactory results. PMID:10593098
Jitpakdi, A; Choochote, W; Insun, D; Tippawangkosol, P; Keha, P; Pitasawat, B
The Delta30 deletion mutation, which was originally created in dengue virus type 4 (DEN4) by the removal of nucleotides 172 to 143 from the 3' untranslated region (3' UTR), was introduced into a homologous region of wild-type (wt) dengue virus type 1 (DEN1). The resulting virus, rDEN1Delta30, was attenuated in rhesus monkeys to a level similar to that of the rDEN4Delta30 vaccine candidate. rDEN1Delta30 was more attenuated in rhesus monkeys than the previously described vaccine candidate, rDEN1mutF, which also contains mutations in the 3' UTR, and both vaccines were highly protective against challenge with wt DEN1. Both rDEN1Delta30 and rDEN1mutF were also attenuated in HuH-7-SCID mice. However, neither rDEN1Delta30 nor rDEN1mutF showed restricted replication following intrathoracic inoculation in the mosquito Toxorhynchites splendens. The ability of the Delta30 mutation to attenuate both DEN1 and DEN4 viruses suggests that a tetravalent DEN vaccine could be generated by introduction of the Delta30 mutation into wt DEN viruses belonging to each of the four serotypes. PMID:12502885
Whitehead, Stephen S; Falgout, Barry; Hanley, Kathryn A; Blaney Jr, Joseph E; Markoff, Lewis; Murphy, Brian R
2Adelta30 is a live dengue-4 virus vaccine candidate with a 30-nucleotide deletion in its 3'-untranslated region. To assess the transmissibility of 2Adelta30 by mosquitoes, we compared its in vivo replication in mosquitoes with that of its wild type DEN-4 parent. Both the vaccine candidate and wild type virus were equally able to infect the mosquito Toxorhynchites splendens after intrathoracic inoculation. Relative to its wild type parent, 2Adelta30 was slightly restricted in its ability to infect the midgut of Aedes aegypti mosquitoes fed on an artificial blood meal and was even more restricted in its ability to disseminate from the midgut to the salivary glands. Thus, the 30-nucleotide deletion rendered the vaccine candidate more sensitive than its wild type parent to the mosquito midgut escape barrier. Most significantly, 2Adelta30 was not transmitted to 352 Ae. albopictus mosquitoes fed on 10 vaccinees, all of whom were infected with the vaccine candidate. PMID:11716092
Troyer, J M; Hanley, K A; Whitehead, S S; Strickman, D; Karron, R A; Durbin, A P; Murphy, B R
The ?30 deletion mutation, which was originally created in dengue virus type 4 (DEN4) by the removal of nucleotides 172 to 143 from the 3? untranslated region (3? UTR), was introduced into a homologous region of wild-type (wt) dengue virus type 1 (DEN1). The resulting virus, rDEN1?30, was attenuated in rhesus monkeys to a level similar to that of the rDEN4?30 vaccine candidate. rDEN1?30 was more attenuated in rhesus monkeys than the previously described vaccine candidate, rDEN1mutF, which also contains mutations in the 3? UTR, and both vaccines were highly protective against challenge with wt DEN1. Both rDEN1?30 and rDEN1mutF were also attenuated in HuH-7-SCID mice. However, neither rDEN1?30 nor rDEN1mutF showed restricted replication following intrathoracic inoculation in the mosquito Toxorhynchites splendens. The ability of the ?30 mutation to attenuate both DEN1 and DEN4 viruses suggests that a tetravalent DEN vaccine could be generated by introduction of the ?30 mutation into wt DEN viruses belonging to each of the four serotypes.
Whitehead, Stephen S.; Falgout, Barry; Hanley, Kathryn A.; Blaney, Jr., Joseph E.; Markoff, Lewis; Murphy, Brian R.
To classify mosquito species based on common features of their habitats, samples were obtained fortnightly between June 2001-October 2003 in the subtropical province of Chaco, Argentina. Data on the type of larval habitat, nature of the habitat (artificial or natural), size, depth, location related to sunlight, distance to the neighbouring houses, type of substrate, organic material, vegetation and algae type and their presence were collected. Data on the permanence, temperature, pH, turbidity, colour, odour and movement of the larval habitat's water were also collected. From the cluster analysis, three groups of species associated by their degree of habitat similarity were obtained and are listed below. Group 1 consisted of Aedes aegypti. Group 2 consisted of Culex imitator, Culex davisi, Wyeomyia muehlensi and Toxorhynchites haemorrhoidalis separatus. Within group 3, two subgroups are distinguished: A (Psorophora ferox, Psorophora cyanescens, Psorophora varinervis, Psorophora confinnis, Psorophora cingulata, Ochlerotatus hastatus-oligopistus, Ochlerotatus serratus, Ochlerotatus scapularis, Culex intrincatus, Culex quinquefasciatus, Culex pilosus, Ochlerotatus albifasciatus, Culex bidens) and B (Culex maxi, Culex eduardoi, Culex chidesteri, Uranotaenia lowii, Uranotaenia pulcherrima, Anopheles neomaculipalpus, Anopheles triannulatus, Anopheles albitarsis, Uranotaenia apicalis, Mansonia humeralis and Aedeomyia squamipennis). Principal component analysis indicates that the size of the larval habitats and the presence of aquatic vegetation are the main characteristics that explain the variation among different species. In contrast, water permanence is second in importance. Water temperature, pH and the type of larval habitat are less important in explaining the clustering of species. PMID:21739026
Stein, Marina; Ludueña-Almeida, Francisco; Willener, Juana Alicia; Almirón, Walter Ricardo
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
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
Fofana, D; Konan, K L; Djohan, V; Konan, Y L; Koné, A B; Doannio, J M C; N'goran, K E
Mosquitoes are more sensitive to sound than any other insect due to the remarkable properties of their antennae and Johnston’s organ at the base of each antenna. Male mosquitoes detect and locate female mosquitoes by hearing the female’s 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. Male–female 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 Johnston’s organ but within the range of mechanical responsiveness of the antennae. We have shown that this is possible because the Johnston’s 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 male–female 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.
Gibson, Gabriella; Warren, Ben
Colonized and field-collected female Culex tarsalis, infected with St. Louis encephalitis, (SLE) virus by intrathoracic inoculation or by feeding on a viremic host, transmitted virus to their F1 adult and/or larval progeny when reared at 18(+/- 1) degree C but not when reared at 27(+/- 1) degrees C. The minimal infection rates (MIR) for different populations of Cx. tarsalis ranged from 1:32 to less than 1:250 (mean = 1:121) for larval progeny and from 1:32 to less than 1:1, 989 (mean = 1:1,571) for adult progeny. SLE virus also was transmitted transovarially by colonized and field-collected populations of Culex pipiens (mean MIRs = 1:340 and 1:1,815 for larval and adult progeny, respectively) and by a field population of Culex quinquefasciatus (MIR = 1:500 and less than 1:246 for larval and adult progeny, respectively), but not by colonized strains of Cx. quinquefasciatus and Culex peus. SLE virus was not recovered in tests on 5,522 Cx. tarsalis and 4,798 Cx. quinquefasciatus that were collected as larvae or pupae from field sites in Southern California and reared to adults at 18 degrees C in the laboratory. Transovarial transmission of SLE virus by Aedes epactius was confirmed and extended to a closely related species, Aedes atropalpus. Efforts to demonstrate transovarial transmission of SLE virus by Aedes melanimon, Aedes sierrensis, and Aedes triseriatus were unsuccessful. Aedes dorsalis, Cx. peus, and Toxorhynchites amboinensis were equally sensitive hosts for viral isolation when inoculated with suspensions of larvae transovarially infected with SLE virus. PMID:6696174
Hardy, J L; Rosen, L; Reeves, W C; Scrivani, R P; Presser, S B
Tick-borne Langat/mosquito-borne dengue flavivirus chimera, a candidate live attenuated vaccine for protection against disease caused by members of the tick-borne encephalitis virus complex: evaluation in rhesus monkeys and in mosquitoes.
Langat virus (LGT), strain TP21, a naturally avirulent tick-borne flavivirus, was used to construct a chimeric candidate virus vaccine which contained LGT genes for premembrane (preM) and envelope (E) glycoprotein and all other sequences derived from dengue type 4 virus (DEN4). The live virus vaccine was developed to provide resistance to the highly virulent, closely related tick-borne flaviviruses that share protective E epitopes among themselves and with LGT. Toward that end the chimera, initially recovered in mosquito cells, was adapted to grow to high titer in qualified simian Vero cells. When inoculated intraperitoneally (i.p.), the Vero cell-adapted LGT TP21/DEN4 chimera remained completely attenuated for SCID mice. Significantly, the chimera protected immunocompetent mice against the most virulent tick-borne encephalitis virus (TBEV). Subsequently, rhesus monkeys were immunized in groups of 4 with 10(5) or 10(7) PFU of LGT strain TP21, with 10(5) PFU of DEN4, or with 10(3), 10(5), or 10(7) PFU of the chimera. Each of the monkeys inoculated with DEN4 or LGT TP21 became viremic, and the duration of viremia ranged from 1 to 5 days. In contrast, viremia was detected in only 1 of 12 monkeys inoculated with the LGT TP21/DEN4 chimera; in this instance the level of viremia was at the limit of detection. All monkeys immunized with the chimera or LGT TP21 virus developed a moderate to high level of neutralizing antibodies against LGT TP21 as well as TBEV and were completely protected against subsequent LGT TP21 challenge, whereas monkeys previously immunized with DEN4 virus became viremic when challenged with LGT TP21. These observations suggest that the chimera is attenuated, immunogenic, and able to induce a protective immune response. Furthermore, passive transfer of serum from monkeys immunized with chimera conferred significant protection to mice subsequently challenged with 100 i.p. 50% lethal doses of the highly virulent TBEV. The issue of transmissibility of the chimera by mosquitoes was addressed by inoculating a nonhematophagous mosquito, Toxorhynchites splendens, intrathoracically with the chimera or its DEN4 or LGT parent. Neither the LGT TP21/DEN4 vaccine candidate nor the wild-type LGT TP21 virus was able to infect this mosquito species, which is highly permissive for dengue viruses. Certain properties of the chimera, notably its attenuation for monkeys, its immunogenicity, and its failure to infect a highly permissive mosquito host, make it a promising vaccine candidate for use in immunization against severe disease caused by many tick-borne flaviviruses. PMID:11483771
Pletnev, A G; Bray, M; Hanley, K A; Speicher, J; Elkins, R
Tick-Borne Langat/Mosquito-Borne Dengue Flavivirus Chimera, a Candidate Live Attenuated Vaccine for Protection against Disease Caused by Members of the Tick-Borne Encephalitis Virus Complex: Evaluation in Rhesus Monkeys and in Mosquitoes
Langat virus (LGT), strain TP21, a naturally avirulent tick-borne flavivirus, was used to construct a chimeric candidate virus vaccine which contained LGT genes for premembrane (preM) and envelope (E) glycoprotein and all other sequences derived from dengue type 4 virus (DEN4). The live virus vaccine was developed to provide resistance to the highly virulent, closely related tick-borne flaviviruses that share protective E epitopes among themselves and with LGT. Toward that end the chimera, initially recovered in mosquito cells, was adapted to grow to high titer in qualified simian Vero cells. When inoculated intraperitoneally (i.p.), the Vero cell-adapted LGT TP21/DEN4 chimera remained completely attenuated for SCID mice. Significantly, the chimera protected immunocompetent mice against the most virulent tick-borne encephalitis virus (TBEV). Subsequently, rhesus monkeys were immunized in groups of 4 with 105 or 107 PFU of LGT strain TP21, with 105 PFU of DEN4, or with 103, 105, or 107 PFU of the chimera. Each of the monkeys inoculated with DEN4 or LGT TP21 became viremic, and the duration of viremia ranged from 1 to 5 days. In contrast, viremia was detected in only 1 of 12 monkeys inoculated with the LGT TP21/DEN4 chimera; in this instance the level of viremia was at the limit of detection. All monkeys immunized with the chimera or LGT TP21 virus developed a moderate to high level of neutralizing antibodies against LGT TP21 as well as TBEV and were completely protected against subsequent LGT TP21 challenge, whereas monkeys previously immunized with DEN4 virus became viremic when challenged with LGT TP21. These observations suggest that the chimera is attenuated, immunogenic, and able to induce a protective immune response. Furthermore, passive transfer of serum from monkeys immunized with chimera conferred significant protection to mice subsequently challenged with 100 i.p. 50% lethal doses of the highly virulent TBEV. The issue of transmissibility of the chimera by mosquitoes was addressed by inoculating a nonhematophagous mosquito, Toxorhynchites splendens, intrathoracically with the chimera or its DEN4 or LGT parent. Neither the LGT TP21/DEN4 vaccine candidate nor the wild-type LGT TP21 virus was able to infect this mosquito species, which is highly permissive for dengue viruses. Certain properties of the chimera, notably its attenuation for monkeys, its immunogenicity, and its failure to infect a highly permissive mosquito host, make it a promising vaccine candidate for use in immunization against severe disease caused by many tick-borne flaviviruses.
Pletnev, Alexander G.; Bray, Michael; Hanley, Kathryn A.; Speicher, Jim; Elkins, Randy