| researches on the development of xenopus laevis larvae fed on tubifex tubifex. i. presence of liposoluble vitamins in the lipid extract from tubifex worms. | vitamin e acetate (alpha-tocopheryl acetate) and related tocopherols, vitamin a acetate (dehydroretinyl acetate), vitamin a alcohol (retinol), and cholesterol were identified by thin-layer chromatography in the lipid extract from tubifex tubifex worms. compounds (perhaps vitamin d precursors, or seroidal substances) absorbing short wave uv light and/or reacting with antimony trichloride were also present but not identified. the results are discussed in relation to the growth, metamorphosis and p ... | 1977 | 576033 |
| early development of khawia sinensis hsü, 1935 (cestoda: caryophyllidea), a carp parasite. | the development of the tapeworm khawia sinensis parasitizing carp (cyprinus carpio l.) has been studied from the release of cestode eggs into water to the formation of infective procercoids in the intermediate host under laboratory conditions. the rate of embryonal development is greatly influenced by the water temperature. while at 5 degrees c the development of oncospheres was not recorded, at 10-12 degrees c, 15 degrees c, 20-22 degrees c, and 23-24 degrees c oncospheres were fully formed aft ... | 1991 | 1937272 |
| review of whole-organism bioassays: soil, freshwater sediment, and freshwater assessment in canada. | whole organism bioassays for the assessment of soil, freshwater sediment, and freshwater quality were evaluated for their application in the assessment and remediation of contaminated sites in canada under the national contaminated sites remediation program. using 3 essential and 12 desirable methodological criteria, bioassays were categorized as currently usable, prototype, or under development. based on further considerations related to bioassay application, a battery of usable screening and d ... | 1995 | 7541337 |
| studies on the occurrence of actinosporean stages of myxosporeans in lake balaton, hungary, with the description of triactinomyxon, raabeia and aurantiactinomyxon types. | in the framework of a one-year survey, the actinosporean infection of the oligochaete fauna living in the mud and on the vegetation of lake balaton, hungary was studied. a total of 10 types of actinospores were isolated from the oligochaetes tubifex tubifex and limnodrilus hoffmeisteri collected during the survey, which could be classified into the triactinomyxon, raabeia and aurantiactinomyxon groups. the drawings depicting the individual actinospore types are presented on a plate and their cha ... | 1998 | 9713145 |
| toxicity of euphorbia milii latex and niclosamide to snails and nontarget aquatic species. | the toxicity of euphorbia milii molluscicidal latex and niclosamide (ncl) to target snails (biomphalaria glabrata and biomphalaria tenagophila) and nontarget aquatic organisms is evaluated. planorbidae snails were killed by very low concentrations of lyophilized latex (48-h lc(50), mg/l: b. glabrata, 0.12; b. tenagophila, 0.09; helisoma duryi, 0.10). latex was less toxic (48-h lc(50) or ec(50), mg/l) to oligochaeta (tubifex tubifex, 0.31), planktonic crustacea (daphnia similis, 0.38; c. dubia, 1 ... | 2000 | 10903832 |
| amino acid sequence of the monomer subunit of the giant extracellular hemoglobin of the aquatic oligochaete, tubifex tubifex. | the extracellular hemoglobin of the aquatic oligochaete tubifex tubifex consists of four subunits: a monomer of 16.5 kda, a disulfide-bonded trimer of about 50 kda and at least two subunits of about 30 kda. the complete amino acid sequence of the monomeric subunit was determined: it consists of 141 amino acid residues and has a molecular mass of 16,286 da including a heme group. 39 residues (28%) were found to be identical with those in the corresponding positions in the monomeric globin chains ... | 1990 | 2253625 |
| light and electron microscopic studies on the chronological development of myxobolus cerebralis to the actinosporean stage in tubifex tubifex. | whirling disease caused by myxobolus cerebralis has become the most widely known disease of salmonids in the 1990s. in the last 5 years we have studied many aspects regarding the host-pathogen relationship of this parasite. the parasite's histozoic development causes significant damage to cartilage and induces cns symptoms by pressure on the brain and spinal cord. myxobolus cerebralis has a two-host life-cycle involving a salmonid fish and a tubificid oligochaete. two different stages of sporogo ... | 1998 | 9504346 |
| environmental health assessment of the benthic habitat adjacent to a pulp mill discharge. i. acute and chronic toxicity of sediments to benthic macroinvertebrates. | in this study, we assessed the acute and chronic toxicity of sediments contaminated by bleached kraft pulp mill effluent (bkme). sediments were collected in august 1991 and 1992, and may 1993 from eight stations exposed directly to the effluent and from four reference sites.acute toxicity was determined for five macroinvertebrates (hyalella azteca, daphnia magna, chironomus riparius, hexagenia spp., and tubifex tubifex) using pore water, elutriate, and bulk sediment exposures. chronic toxicity w ... | 1997 | 9096076 |
| [new details of the life cycle of myxobolus cerebralis according to the literature]. | the article comprises new details of the life cycle of myxobolus cerebralis, the parasite of the skeleton of salmonids. although this species has been known since 1903, its complete life cycle has remained unknown till now or it has comprised mistaken details. recently el matbouli et al. (1995) have described the life cycle of this parasite with numerous new data. m. cerebralis provokes in salmonids (especially in rainbow trouts) the whirling disease and heavy economical losses. therefore the ar ... | 1996 | 9012131 |
| toxicity of 4-nonylphenol to tubifex tubifex and chironomus riparius in 28-day whole-sediment tests. | concern has been growing recently over the toxicity and the mimicking properties of 4-nonylphenol (4np), the most persistent breakdown product of the nonionic surfactant nonylphenol ethoxylates, broadly used in industrial cleaning processes. twenty-eight-day tests were performed to evaluate the toxicity and the effects on reproduction of 4np spiked sediment to the benthic invertebrates tubifex tubifex and chironomus riparius. 4np was directly added to the wet sediment, avoiding any solvent. the ... | 2002 | 12481866 |
| factors influencing the distribution of myxobolus cerebralis, the causative agent of whirling disease, in the cache la poudre river, colorado. | oligochaetes, triactinomyxons (tams), and age-0 trout were sampled in the upper cache la poudre river, colorado, to determine the distribution of myxobolus cerebralis during 1997 and 1998. densities of the intermediate host, the oligochaete tubifex tubifex, were 3.5 orders of magnitude higher in the m. cerebralis-infected poudre rearing unit (pru) trout rearing ponds than at any of the river sampling reaches. oligochaetes, including t. tubifex, were rare in the river (1 oligochaete m(-2)), excep ... | 2002 | 12093042 |
| development of myxobolus macrocapsularis (myxosporea: myxobolidae) in an oligochaete alternate host, tubifex tubifex. | the development of myxobolus macrocapsularis reuss, 1906, a myxosporean parasite of the gills of common bream abramis brama l., was studied in experimentally infected oligochaetes. in 3 experiments uninfected tubifex tubifex muller and limnodrilus hoffmeisteri (claparéde) were exposed to mature myxospores of m. macrocapsularis. in all experiments, typical triactinospores developed in t. tubifex specimens but no infection was found in l. hoffmeisteri. triactinospores were released from oligochaet ... | 2002 | 12005233 |
| comparative ultrastructure of the actinosporean stages of myxobolus bramae and m. pseudodispar (myxozoa). | the ultrastructrure of triactinospores and other developmental stages obtained after the experimental infection of the oligochaete tubifex tubifex with myxospores of myxobolus bramae and myxobolus pseudodispar was studied. in both cases, pansporocysts harbouring spores and the remnants of polar bodies were found in the gut epithelium of the tubificids. other stages were also seen in m. pseudodispar. capsulogenic cells surrounded the apical part of the sporoplasm in m. bramae whereas they were lo ... | 2002 | 11954904 |
| first record of actinosporean stages of fish myxosporean parasites (myxozoa: myxosporea) in egypt. | in the present study the actinosporean infestation of the oligochaete fauna has been studied. for first time in egypt, a total of 6 different types of actinospores were isolated from the filtrated water contained oligochaetes limnodrilus hoffmeisteri, tubifex tubifex, branchiura sowerbyei and dero digitata. these new types are classified to hexactinospores and triactinospores. the drawings depicting these actinospore types are constructed and their characteristic dimensions are calculated. the o ... | 2001 | 11478445 |
| recent advances in our knowledge of the myxozoa. | in the last few years two factors have helped to significantly advance our understanding of the myxozoa. first, the phenomenal increase in fin fish aquaculture in the 1990s has lead to the increased importance of these parasites; in turn this has lead to intensified research efforts, which have increased knowledge of the development, diagnosis. and pathogenesis of myxozoans. the hallmark discovery in the 1980s that the life cycle of myxobolus cerebralis requires development of an actinosporean s ... | 2001 | 11456316 |
| molecular phylogeny of tubificid oligochaetes with special emphasis on tubifex tubifex (tubificidae). | tubifex tubifex is a cosmopolitan freshwater oligochaete whose presence has been studied as a health indicator of the aquatic environment and as a host for several myxozoan parasites of fish. unfortunately, current morphological criteria used to distinguish tubifex spp. (tubificidae) are inadequate. we therefore developed mitochondrial 16s ribosomal dna markers to examine phylogenetic relationships among aquatic oligochaetes and to distinguish species of tubifex that might serve as hosts for a p ... | 2001 | 11341804 |
| the effects of myxobolus cerebralis myxospore dose on triactinomyxon production and biology of tubifex tubifex from two geographic regions. | the aquatic oligochaete tubifex tubifex is an obligate host of myxobolus cerebralis, the causative agent of salmonid whirling disease. tubifex tubifex can become infected by ingesting myxospores of m. cerebralis that have been released into sediments upon death and decomposition of infected salmonids. infected worms release triactinomyxons into the water column that then infect salmonids. how the dose of myxospores ingested by t. tubifex influences parasite proliferation and the worm host are no ... | 2001 | 11318561 |
| persistent infection of myxobolus cerebralis, the causative agent of salmonid whirling disease, in tubifex tubifex. | the objective of this study was to quantify and determine the periodicity in the release of the triactinomyxon (tam) stage of myxobolus cerebralis, the causative agent of salmonid whirling disease, by its aquatic oligochaete host tubifex tubifex. for this, 24 individual t. tubifex (infected as a group at 15 c) were examined daily for the release of m. cerebralis tams, and the number of waterborne tams released by each worm was quantified. the duration of the infection in these worms was also mon ... | 2001 | 11227872 |
| the life cycle of sphaerospora truttae (myxozoa: myxosporea) and some features of the biology of both the actinosporean and myxosporean stages. | a previously undescribed echinactinomyxon type actinosporean was shown experimentally to be the alternate stage of sphaerospora truttae. the echinactinomyxon type spores were found to be released from lumbriculus variegatus and occasionally tubifex tubifex. overall infection prevalence of the echinactinomyxon was 0.14%. peak release was in march-may each year. s. truttae spores developed in experimentally infected salmon 4.5 mo post-exposure to echinactinomyxon spores. extrasporogonic stages of ... | 2000 | 10785861 |
| experimental detection of the actinospores of myxobolus pseudodispar (myxosporea: myxobolidae) in oligochaete alternate hosts. | the development of myxobolus pseudodispar gorbunova, 1936, an intracellular myxosporean muscle parasite of the roach rutilus rutilus l., was studied in experimentally infected oligochaetes. in one experiment, uninfected tubifex tubifex müller and limnodrilus hoffmeisteri (claparéde) were exposed to mature spores of m. pseudodispar. triactinomyxon spores developed both in t. tubifex and l. hoffmeisteri specimens. triactinospores were first released from the oligochaetes 76 d after initial exposur ... | 1999 | 10686672 |
| effect of water temperature on the development, release and survival of the triactinomyxon stage of myxobolus cerebralis in its oligochaete host. | the development of the triactinomyxon stage of myxobolus cerebralis and release of mature spores from tubifex tubifex were shown to be temperature dependent. in the present work, the effect of temperature over a range of 5-30 degrees c on the development and release of the triactinomyxon stages of m. cerebralis was studied. infected t. tubifex stopped releasing triactinomyxon spores 4 days after transfer from 15 degrees c to 25 degrees c or 30 degrees c. transmission electron microscopic examina ... | 1999 | 10428640 |
| actinosporean stages of myxozoan parasites of oligochaetes from lake sasajewun, algonquin park, ontario: new forms of echinactinomyxon, neoactinomyxum, aurantiactinomyxon, guyenotia, synactinomyxon and antonactinomyxon. | six forms (5 of which are new) of echinactinomyxon and 5 new forms of the collective groups neoactinomyxum, aurantiactinomyxon, guyenotia, synactinomyxon, and antonactinomyxon of oligochaetes in lake sasajewun, algonquin park are described. five forms of echinactinomyxon designated as echinactinomyxon 'a,' 'b,' 'c,' 'd,' and 'e,' a form of neoactinomyxum, and a form of aurantiactinomyxon were found in limnodrilus hoffmeisteri. echinactinomyxon radiatum, a form of synactinomyxon, and a form of an ... | 1998 | 9794645 |
| determination of nuclear dna concentration in cells of myxobolus cerebralis and triactinomyxon spores, the causative agent of whirling disease. | myxobolus cerebralis (myxozoa: myxosporea) has a complex two-host life cycle, which begins when waterborne triactinomyxon spores released from the infected oligochaete tubifex tubifex contact a susceptible trout. upon contact the triactinomyxon spores attach to the fish and release their sporoplasm cells into the epidermis. at approximately 50 days postinfection, sporogenesis begins, resulting in a large number of m. cerebralis spores in the cartilage of infected fish 6 weeks later. the spores o ... | 1998 | 9766896 |
| myxobolus cerebralis in tubifex tubifex from a whirling disease epizootic in montana. | aquatic oligochaetes from a whirling disease enzootic area in southwest montana were examined for infection with myxobolus cerebralis. anterior portions of oligochaetes were preserved for specific identification, whereas dna was purified from posterior portions. the purified dna was used in a nested polymerase chain reaction (pcr) assay specific for m. cerebralis small-subunit ribosomal dna. naturally infected oligochaetes were identified by a resulting 415-bp fragment of amplified parasite dna. ... | 1998 | 9714199 |
| studies on the occurrence of actinosporean stages of fish myxosporeans in a fish farm of hungary, with the description of triactinomyxon, raabeia, aurantiactinomyxon and neoactinomyxon types. | actinosporean infection of the oligochaete fauna living in the mud and on the vegetation of fish ponds used for rearing common carp in polyculture was studied during a one-year survey at a fish farm in hungary, located south of budapest. twenty-eight actinospore types were isolated from the oligochaetes tubifex tubifex, branchiura a sowerbyi, limnodrilus hoffmeisteri, nais elinguis, and stylaria lacustris collected during the survey, which could be classified into the triactinomyxon, raabeia, au ... | 1998 | 9704528 |
| extrapiscine development of myxobolus drjagini akhmerov, 1954 (myxosporea: myxobolidae) in oligochaete alternative hosts. | the extrapiscine development of myxobolus drjagini, a myxosporean parasite of the head, operculum and buccal cavity of the silver carp (hypophthalmichthys molitrix), was studied in experimentally infected oligochaetes, tubifex tubifex. after infection of uninfected tubificids with mature spores of m. drajagini, development of actinosporean stages was first observed by light microscopy 27 days after infection. triactinomyxon stages of m. drjagini emerged from the worms after 91 days of intraoligo ... | 1997 | 9557320 |
| prevalence and susceptibility of infection to myxobolus cerebralis, and genetic differences among populations of tubifex tubifex. | the prevalence of infection and susceptibility of the aquatic oligochaete tubifex tubifex to myxobolus cerebralis, was examined in 2 studies on the upper colorado river, colorado, usa, where whirling disease occurs in wild trout populations. in the first study, the prevalence of infection ranged from 0.4 to 1.5%, as determined by counting the number of t. tubifex releasing triactinomyxons of m. cerebralis directly following their collection from the field. the susceptibility of those t. tubifex ... | 2002 | 12363083 |
| the effect of cohabitation of tubifex tubifex (oligochaeta: tubificidae) populations on infections to myxobolus cerebralis (myxozoa: myxobolidae). | the competitive interactions between susceptible and resistant tubifex tubifex (oligochaeta: tubificidae) exposed to myxobolus cerebralis (myxozoa: myxobolidae) infections were investigated in two laboratory trials. competition was assessed by the total parasite production over the course of the trials in mixed and pure cultures of m. cerebralis exposed worms, and by the genetic analyses of worms from the control and experimental groups at the beginning and end of the experiments. mixed cultures ... | 2006 | 16321396 |
| alternation of actinosporean and myxosporean phases in the life cycle of zschokkella nova (myxozoa). | experimental evidence has been gathered to show that the life cycle of the myxozoan gallbladder parasite zschokkella nova klokacewa, 1914, which infects the fish carassius carassius, has a complex life cycle with alternation of two hosts (fish and oligochaeta) and two developmental phases (myxosporean and actinosporean). the gut epithelium of the oligochaete, tubifex tubifex, exposed experimentally to z. nova, obtained from c. carassius, became infected with organisms resembling actinosporea. th ... | 1995 | 8520578 |
| metallothioneins induction and antioxidative response in aquatic worms tubifex tubifex (oligochaeta, tubificidae) exposed to copper. | metallothioneins (mts), are low molecular weight proteins, mainly implicated in metal ion detoxification. increase in mt contents is considered as a specific biomarker of metal exposure. recently it has been demonstrated that mts participate in several cellular functions such as regulation of growth, and antioxidative defences. tubifex tubifex were exposed to different copper concentrations (50, 100, and 200 microgl(-1)) for 7 and 15 days. mt levels in exposed worms increased significantly (p<0. ... | 2006 | 16330073 |
| glutathione s-transferase in aquatic macro-invertebrates and its interaction with different organic micropollutants. | in higher organisms, glutathione s-transferase (gst) plays a key role in the detoxification of a large number of xenobiotics. in the present work the presence of gst in aquatic macro-invertebrates and its possible significance as a detoxification mechanism of organic micropollutants in the aquatic environment is investigated. so far, gst has been found in 20 macro-invertebrates (in adults as well as in larvae) and in insects as well as in other animal groups. the gst activities were relatively h ... | 1984 | 6523136 |
| host-parasite relationships of caryophyllaeid cestodes and aquatic oligochaetes: ii. effects of host age and mixed infections. | experiments were conducted to assess the relationship between annelid age and susceptibility of the annelid as an intermediate host for a caryophyllaeid, as well as the effect a mixed-species infection has on rate of metacestode development and parasite mortality. four host-parasite systems were studied: biacetabulum biloculoides and hunterella nodulosa in limnodrilus hoffmeisteri and glaridacris catostomi in ilyodrilus templetoni and tubifex tubifex. annelids were divided into 3 age classes: im ... | 1988 | 3397818 |
| the development of eustrongylides tubifex (nematoda: dioctophymatoidea) in oligochaetes. | egg development of eustrongylides tubifex (nitzsch in rudolphi, 1819) jägerskiöld, 1909, was studied at 5, 10, 15, 20, 25, and 30 c. eggs developed at 20, 25, and 30 c. development ceased at 0, 5, 10, and 15 c but resumed when temperatures were raised. eggs contained first-stage larvae in 23-26 days at 25 c. seven species of aquatic oligochaetes were exposed experimentally to eggs of e. tubifex containing first-stage larvae. third-stage larvae of e. tubifex developed in the aquatic oligochaetes, ... | 1988 | 3357121 |
| the role of tubificid oligochaetes in the transmission of goussia carpelli. | tubifex tubifex and limnodrilus hoffmeisteri, fed intestinal tissue of carp containing oocysts of goussia carpelli, produced infections in laboratory-reared carp. sporocysts ingested by the tubificids released the sporozoites that were found to be motile in the intestinal contents and incorporated in intestinal cells of the oligochaetes. tubificids remained infective for carp at least up to 57 days postexposure (pe). tubificids were also able to transmit g. carpelli to carp that had recovered fr ... | 1990 | 2299515 |
| cadmium-induced production of a metallothioneinlike protein in tubifex tubifex (oligochaeta) and chironomus riparius (diptera): correlation with reproduction and growth. | laboratory-cultured chironomus riparius and tubifex tubifex were exposed to sediments artificially enriched with a range of cadmium (cd) concentrations. both species accumulated cd in a concentration-dependent manner. the concentration of a metallothioneinlike protein (mtlp), as measured by a mercury saturation assay, increased with increasing cd exposure. after reaching a threshold of cd exposure, the whole-body endpoints of reproductive output in t. tubifex and growth in c. riparius declined s ... | 2002 | 12206423 |
| effects of water temperature and substrate type on spore production and release in eastern tubifex tubifex worms infected with myxobolus cerebralis. | eastern tubifex tubifex worms were exposed to myxobolus cerebralis spores at 9, 13, 17, and 20 c in 1-l jars that contained sand, mud, or leaf litter as substrata. beginning 60 days after exposure, water from each jar was filtered daily and examined for the presence of waterborne triactinomyxon spores (tams). on discovering a single tam from an experimental jar, 48 t. tubifex worms from that jar were placed individually into 24-well plates. spores released from individual infected t. tubifex wor ... | 2003 | 12659298 |
| the relative sensitivity of four benthic invertebrates to metals in spiked-sediment exposures and application to contaminated field sediment. | the relative sensitivity of four benthic invertebrates (hyalella azteca, chironomus riparius, hexagenia spp., and tubifex tubifex) was determined for cd, cu, and ni in water-only and in spiked-sediment exposures. survival (median lethal concentrations [lc50s] and the concentrations estimated to be lethal to 25% of test organisms [lc25s]), and endpoints for growth and reproduction (mean inhibitory concentrations [ic25s]) were compared. the sensitivities differed depending on the species and metal ... | 2003 | 12685721 |
| degradation and detoxification of endosulfan isomers by a defined co-culture of two bacillus strains. | the degradation of alpha and beta isomers of endosulfan by a two-member bacterial co-culture was studied. results were similar whether the two isomers were present individually or together, as in technical endosulfan. the degradation of both isomers was accompanied by the formation of endosulfan diol and endosulfan lactone. accumulation of the metabolite, endosulfan sulfate was, however, not observed during the reaction with either of the isomers. the microbial degradation of endosulfan isomers ... | 2003 | 12883876 |
| chemical analysis and sediment toxicity bioassays to assess the contamination of the river lambro (northern italy). | this study consisted of a 10-day whole sediment toxicity test with the chironomid chironomus riparius and a 28-day sediment toxicity test with the oligochaete tubifex tubifex at seven sites to assess the quality of the river lambro (italy), one of the most contaminated rivers of the po basin. endpoints measured were survival and growth for chironomids and cocoon deposition and development of young worms for tubificid oligochaetes. responses were evaluated in relation to the occurence of organic ... | 2003 | 12948175 |
| toxicity of copper-spiked sediments to tubifex tubifex (oligochaeta, tubificidae): a comparison of the 28-day reproductive bioassay with a 6-month cohort experiment. | results from a 28-day adult reproductive bioassay using the aquatic oligochaete tubifex tubifex (müller, 1774) are compared with life table statistics obtained from a 6-month experiment on cohorts of the same species. this was done by simultaneously performing the two tests on copper spiked sediments. five concentrations and a control were tested. the 28-day bioassay was performed 3 times in succession. several endpoints were considered for each test and loec, ic10 and ic50 were calculated. ic50 ... | 2003 | 13678845 |
| whirling disease of salmonid fish: life cycle, biology, and disease. | myxobolus cerebralis is the myxozoan parasite responsible for causing whirling disease in salmonid fish. although the parasite was first described nearly 100 yr ago, it received relatively little attention until the discovery of its 2-host life cycle in the mid 1980s. this was the first, complete, myxozoan life cycle to be described, and it was greeted with some skepticism because it united 2 stages of m. cerebralis that were previously classified in 2 separate taxa. in the last decade, there ha ... | 2003 | 14533670 |
| efficacy of passive sand filtration in reducing exposure of salmonids to the actinospore of myxobolus cerebralis. | the aquatic oligochaete tubifex tubifex parasitized by myxobolus cerebralis releases triactinomyxon (tam) actinospores that can infect some species of salmonids and cause salmonid whirling disease. silica sand was tested as a filtration medium for removal of tams from water containing the parasite. laboratory tests indicated sand filtration removed > 99.99% of tams. in 2 different field tests, groups of 1 mo old rainbow trout oncorhynchus mykiss were exposed for 2 wk to filtered and unfiltered w ... | 2003 | 14735924 |
| variability in triactinomyxon production from tubifex tubifex populations from the same mitochondrial dna lineage infected with myxobolus cerebralis, the causative agent of whirling disease in salmonids. | myxobolus cerebralis, the causative agent of whirling disease, infects both salmonid fish and an aquatic oligochaete, tubifex tubifex. although m. cerebralis has been detected in river drainages throughout the united states, disease severity among wild fish populations has been highly variable. tubifex tubifex populations have been genetically characterized using sequences from the 16s mitochondrial dna (mtdna) gene, the 18s ribosomal rna gene, the internal transcribed spacer region 1 (its1), an ... | 2008 | 18605778 |
| sediment toxicity testing using large water-sediment ratios: an alternative to water renewal. | deterioration of overlying water quality during toxicity tests with benthic invertebrates is a serious problem with some sediments. one solution is periodic renewal of overlying water. however, this is either labour intensive or requires construction and maintenance of special equipment. furthermore, water renewal has the potential for flushing toxic chemicals out of the test chamber and establishes nonequilibrium conditions between the water and sediment. an alternative is testing under static ... | 1999 | 15093029 |
| comparison of 17 biotests for detection of cyanobacterial toxicity. | the aim of the present study was to compare the sensitivity of 17 acute bioassays of cyanobacterial toxicity by assessment of crude extracts of three cyanobacterial samples (all dominated by microcystis sp. but substantially differing in microcystin-lr content). toxicity of the fractions prepared by solid-phase extraction (spe) for microcystins was also determined. the most sensitive bioassay was the 24-h test with crustacean thamnocephalus platyurus, which elicited high lethality in the samples ... | 2004 | 15269901 |
| potential for dissemination of the nonnative salmonid parasite myxobolus cerebralis in alaska. | myxobolus cerebralis, the myxozoan parasite responsible for whirling disease in salmonids, was first introduced into the united states in 1958 and has since spread across the country, causing severe declines in wild trout populations in the intermountain western united states. the recent detection of the parasite in alaska is further evidence of the species' capability to invade and colonize new habitat. this study qualitatively assesses the risk of further spread and establishment of m. cerebra ... | 2008 | 18942590 |
| intraoligochaete development of myxobolus intimus (myxosporea: myxobolidae), a gill myxosporean of the roach (rutilus rutilus). | the infection with myxobolus intimus zaika, 1965 in the gills of the roach rutilus rutilus (l.) from lake balaton was recorded in 28 out of the 39 fish examined. developing and mature plasmodia were detected on the gills exclusively in the spring. the myxobolus intimus infection was found only in 2- to 3-year-old fish. in histological sections, young plasmodia were found in capillaries of the secondary lamellae. more mature, round plasmodia 0.4-0.6 mm in diameter, deformed the respiratory lamell ... | 2004 | 15357397 |
| extensive release of an antigen associated with the sporogonic stages of myxobolus cerebralis (myxozoa: myxosporea) is detected by a heterologous antibody raised to tetracapsuloides bryosalmonae (myxozoa: malacosporea). | monoclonal antibody b4 (mab b4) was previously developed to the myxozoan parasite tetracapsuloides bryosalmonae canning, curry, feist, longshaw et okamura, 1999, the causative agent of proliferative kidney disease of salmonids, here we describe the reaction of mab b4 against myxobolus cerebralis hofer, 1903, the parasite that causes 'whirling disease' in salmonids. tissues examined were collected from experimentally infected rainbow trout oncorhynchus mykiss (walbaum) and the aquatic oligochaete ... | 2004 | 15357400 |
| metallothionein induction, antioxidative responses, glycogen and growth changes in tubifex tubifex (oligochaete) exposed to the fungicide, fenhexamid. | laboratory studies were conducted to determine the effects of different concentrations of fenhexamid (0.1, 1, and 10 mg l(-1)) on growth, oxidative stress, protein, glycogen, and metallothionein (mt) contents in tubifex tubifex after an exposure of 2, 4, and 7 days. in addition, residues of the fungicide were followed in water and in the worms. in water, fenhexamid concentration decreased slowly (maximum -2 +/- 0.03% after 2 days for 1 mg l(-1)). in the worms, it increased after 4 days and decre ... | 2005 | 15701394 |
| the life cycle of henneguya nuesslini schuberg & schroder, 1905 (myxozoa) involves a triactinomyxon-type actinospore. | the life cycle of the histozoic myxozoan parasite henneguya nuesslini was investigated in two salmonid host species. naive brown trout, salmo trutta, and brook trout, salvelinus fontinalis, were experimentally infected in two trials by triactinomyxon type actinospores from naturally infected tubifex tubifex. in exposed common carp, cyprinus carpio, no myxospore production was detected. the parasite formed cysts with mature myxospores in the connective tissue of the fish 102 days post-exposure. t ... | 2005 | 15705152 |
| differential propagation of the metazoan parasite myxobolus cerebralis by limnodrilus hoffmeisteri, ilyodrilus templetoni, and genetically distinct strains of tubifex tubifex. | whirling disease, caused by the parasite myxobolus cerebralis, has infected rainbow trout (oncorhynchus mykiss) and other salmonid fish in the western united states, often with devastating results to native populations but without a discernible spatial pattern. the parasite develops in a complex 2-host system in which the aquatic oligochaete tubifex tubifex is an obligate host. because substantial differences in whirling disease severity in different areas of north america did not seem explainab ... | 2004 | 15715230 |
| dissemination of triactinomyxons (myxozoa) via oligochaetes used as live food for aquarium fishes. | freshwater 'tubifex' oligochaetes sold as live food for aquarium fishes were purchased from several pet shops in munich, germany, over a 1 yr period (march 2001 to february 2002). these samples were screened for parasitic infections of actinosporean myxozoans to gauge the possibility of parasite dispersal via this route. of 7 samples, 6 contained infected oligochaetes; waterborne spores were present in 5 samples at the time of purchase. in the laboratory, 12 different types of actinosporeans wer ... | 2005 | 16060267 |
| characterisation of carbohydrate-binding sites in developmental stages of myxobolus cerebralis. | glycans and lectins (carbohydrate-binding molecules) form a mutual recognition system, which enables parasitic organisms to attach themselves to the host cells and/or take part in the migration of their developmental stages into the target tissue. the aim of the present study was to identify and characterise the potential binding activity of glycoconjugates in different developmental stages of myxobolus cerebralis, the causative agent of whirling disease in salmonids. the binding patterns of 13 ... | 2005 | 16211413 |
| decolourisation and detoxification of synthetic molasses melanoidins by individual and mixed cultures of bacillus spp. | the decolourisation of synthetic melanoidins (i.e., gga, gaa, sga, and saa) by three bacillus isolates (bacillus thuringiensis (mtcc 4714), bacillus brevis (mtcc 4716) and bacillus sp. (mtcc 6506)) was studied. significant reduction in the values of physicochemical parameters was noticed alongwith the decolourisation of all four melanoidins (10% v/v). b. thuringiensis (mtcc 4714) caused maximum decolourisation followed by b. brevis (mtcc 4716) and bacillus sp. (mtcc 6506). a mixed culture compri ... | 2006 | 16321521 |
| effects of temperature on the sensitivity of sludge worm tubifex tubifex müller to selected heavy metals. | the present study evaluates the effect of temperature on the sensitivity of the freshwater tubificid sludge worm tubifex tubifex müller to 10 heavy metal ions. metals used in this study were cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, and zinc. the acute toxicity of these heavy metals was studied at 15, 20, 25, and 30 degrees c. the percentage mortality, relative toxicity, and ec50 values and their 95% confidence limits from 24 to 96 h were determined at varying te ... | 2002 | 12481853 |
| description of two new actinosporean types from a brook of fuji mountain, honshu, and from chitose river, hokkaido, japan. | actinospore infection of oligochaetes living in the mud of 3 freshwater biotopes in japan was studied. using the cell-well plate method, a new aurantiactinomyxon type was found in 0.77% of the examined tubifex tubifex oligochaete specimens from a brook near yamanashi prefectural fisheries experimental station on fuji mountain. in 0.14% of lumbriculus variagetus collected from chitose river, near chitose salmon hatchery, a new siedleckiella type was found, while at the same time 8.1% of the lumbr ... | 2003 | 12650245 |
| interactions among two strains of tubifex tubifex (oligochaeta: tubificidae) and myxobolus cerebralis (myxozoa). | host-parasite interactions influence host population growth, host evolution and parasite success. we examined the interactions among myxobolus cerebralis, the parasite that causes salmonid whirling disease, and resistant and susceptible strains of the oligochaete host tubifex tubifex. strains of t. tubifex with diverse genotypes often coexist in nature and have variable susceptibilities to m. cerebralis infection. further, parasite proliferation differs by several orders of magnitude among t. tu ... | 2006 | 16532604 |
| epizootiology of myxobolus cerebralis, the causative agent of salmonid whirling disease in the rock creek drainage of west-central montana. | whirling disease, caused by the myxozoan parasite myxobolus cerebralis, remains a health threat to salmonid fish in the western united states. although various aspects of this host-parasite system have been studied, investigations examining the overall epizootiology of whirling disease in an ecosystem are lacking. therefore, in june 1998, studies were initiated in the rock creek watershed of west-central montana and continued through 2003 to assess the intensity of infection in trout using senti ... | 2007 | 17436949 |
| the tubifex tubifex assay for the determination of acute toxicity. | an express (3-minute) test for acute toxicity determination by using the oligochaete annelid, tubifex tubifex, is described. the ec50(tubifex tubifex) [ec50(tt)] for movement inhibition was calculated by using a concentration-response dependence. the reproducibility of the test was checked over several years and by several workers. its applicability is limited to compounds which are soluble in water. the calculated ec50(tt) indices correlate with lc50 values determined by using the fish, pimepha ... | 2007 | 17559312 |
| chronic toxicity of copper to five benthic invertebrates in laboratory-formulated sediment: sensitivity comparison and preliminary risk assessment. | five benthic organisms commonly used for sediment toxicity testing were chronically (28 to 35 days) exposed to copper in standard laboratory-formulated sediment (following organization for economic cooperation and development guidelines) and lethal and sub-lethal toxicities were evaluated. sub-lethal endpoints considered were reproduction and biomass production for lumbriculus variegatus, growth and reproduction for tubifex tubifex, growth and emergence for chironomus riparius, and growth for ga ... | 2007 | 17631947 |
| arrested development of the myxozoan parasite, myxobolus cerebralis, in certain populations of mitochondrial 16s lineage iii tubifex tubifex. | laboratory populations of tubifex tubifex from mitochondrial (mt)16s ribosomal dna (rdna) lineage iii were generated from single cocoons of adult worms releasing the triactinomyxon stages (tams) of the myxozoan parasite, myxobolus cerebralis. subsequent worm populations from these cocoons, referred to as clonal lines, were tested for susceptibility to infection with the myxospore stages of m. cerebralis. development and release of tams occurred in five clonal lines, while four clonal lines showe ... | 2008 | 17891544 |
| characterization of glycans in the developmental stages of myxobolus cerebralis (myxozoa), the causative agent of whirling disease. | glycans and sugar-binding molecules (lectins) form an interactive recognition system, which may enable parasitic organisms to adhere to host cells and migrate into target tissues. the aim of the present study was to analyse surface-associated glycans in the developmental stages of myxobolus cerebralis (hofer), the causative agent of whirling disease. a panel of biotin-labelled plant lectins was used to detect a broad spectrum of glycan motifs with high specificity. binding sites were detected hi ... | 2007 | 17958607 |
| tubifex tubifex from alaska and their susceptibility to myxobolus cerebralis. | although widespread throughout the continental united states, myxobolus cerebralis, the myxozoan parasite that causes whirling disease in salmonids, has not been reported from the state of alaska. as part of a risk assessment for the introduction and establishment of m. cerebralis into alaska, the distribution of the invertebrate host tubifex tubifex was surveyed, and its genetic composition and susceptibility to the parasite were determined. many oligochaetes, but no t. tubifex, were collected ... | 2007 | 18314677 |
| the internal distribution of nickel and thallium in two freshwater invertebrates and its relevance to trophic transfer. | although nickel and thallium are present at potentially harmful concentrations in some lakes, there is little information on their bioaccumulation and transfer up aquatic food webs. to measure the propensity of animals for accumulating and transferring these contaminants along food chains, we exposed two common types of invertebrates, an insect (chironomus riparius) and a worm (tubifex tubifex), to these metals spiked into sediment. we then measured the subcellular distribution of ni and tl in t ... | 2008 | 18754361 |
| effects of freezing, drying, ultraviolet irradiation, chlorine, and quaternary ammonium treatments on the infectivity of myxospores of myxobolus cerebralis for tubifex tubifex. | the effects of freezing, drying, ultraviolet irradiation (uv), chlorine, and a quaternary ammonium compound on the infectivity of the myxospore stage of myxobolus cerebralis (the causative agent of whirling disease) for tubifex tubifex were examined in a series of laboratory trials. freezing at either -20 degrees c or -80 degrees c for a period of 7 d or 2 months eliminated infectivity as assessed by the absence of production of the actinospore stage (triactinomyxons [tams]) from t. tubifex cult ... | 2008 | 18783133 |
| some remarks on the occurrence, host-specificity and validity of myxobolus rotundus nemeczek, 1911 (myxozoa: myxosporea). | myxobolus rotundus nemeczek, 1911 is a common and specific parasite of the common bream abramis brama (l.). small, round or ellipsoidal shaped plasmodia of this species develop in the gill and exhibit strong histotropism to the secondary gill lamellae with plasmodial development in their capillary network. m. rotundus is frequently found in mixed infection with m. bramae reuss, 1906, a parasite of the afferent arteries of gill filaments. the round spores of m. rotundus resemble several other myx ... | 2009 | 19048408 |
| selenium assimilation and loss by an insect predator and its relationship to se subcellular partitioning in two prey types. | subcellular selenium (se) distributions in the oligochaete tubifex tubifex and in the insect chironomus riparius did not vary with se exposure duration, which was consistent with the observations that the duration of prey se exposure had little influence on either se assimilation or loss by a predatory insect (the alderfly sialis velata). however, these two prey types differed in how se was distributed in their cells. overall, the predator assimilated a mean of 66% of the se present in its prey, ... | 2009 | 19110352 |
| influence of chironomus riparius (diptera, chironomidae) and tubifex tubifex (annelida, oligochaeta) on oxygen uptake by sediments. consequences of uranium contamination. | the diffusive oxygen uptake (dou) of sediments inhabited by chironomus riparius and tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. after 72h, the two invertebrate species significantly increased the dou of sediments (13-14%), and no temporal variation occurred afterwards. within contaminated sedim ... | 2009 | 19121883 |
| subcellular distribution of cadmium in two aquatic invertebrates: change over time and relationship to cd assimilation and loss by a predatory insect. | we set out to determine if the efficiency of cadmium (cd) assimilation and loss by a freshwater predator (the alderfly sialis velata) differs when it is exposed, for various lengths of time, to cd in either an insect (chironomus riparius) or a worm (tubifex tubifex). prey were exposed to cd in sediments for up to 28 days and then fractionated to measure cd distributions in their cells. cadmium subcellular distributions varied little over time for a given preytype but differed substantially betwe ... | 2009 | 19238964 |
| myxobolus cerebralis (myxozoa), the causative agent of whirling disease, reduces fecundity and feeding activity of tubifex tubifex (oligochaeta). | myxobolus cerebralis is the causative agent of whirling disease that has significant economical and ecological impacts on trout populations. although intensive studies have been conducted to understand its effects on and interactions with its fish host, only limited information is available about how and to what extent m. cerebralis affects its oligochaete host, tubifex tubifex. we investigated the effects of m. cerebralis on survival, growth, reproduction, and feeding activity of t. tubifex. ma ... | 2009 | 19284888 |
| effects of uranium-contaminated sediments on the bioturbation activity of chironomus riparius larvae (insecta, diptera) and tubifex tubifex worms (annelida, tubificidae). | freshwater sediments represent a compartment for accumulation of toxic substances, notably of metallic pollutants such as uranium. however, they also constitute a privileged habitat for many benthic macro-invertebrate species with important roles in the functioning of these ecosystems, particularly through their bioturbation activities. uranium accumulation in sediments can thus have harmful effects on these organisms (e.g., developmental delay, malformations, mortality). the present study aimed ... | 2009 | 19403158 |
| propagation of the myxozoan parasite myxobolus cerebralis by different geographic and genetic populations of tubifex tubifex: an oregon perspective. | tubifex tubifex are obligate invertebrate hosts in the life cycle of myxobolus cerebralis, the myxozoan parasite that causes whirling disease in salmonid fishes. this exotic parasite is established to varying degrees across oregon's columbia river system (pacific northwest, usa) and characteristics of local t. tubifex populations likely play a role in the pattern of disease occurrence. to better understand these patterns, we collected t. tubifex from three oregon river basins (willamette, deschu ... | 2009 | 19583968 |
| acute toxicity of metals and reference toxicants to a freshwater ostracod, cypris subglobosa sowerby, 1840 and correlation to ec(50) values of other test models. | the ostracod cypris subglobosa sowerby, 1840 static bioassay test on the basis of a 48h of 50% of immobilization (ec(50)) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. among the 36 metals and metalloids, osmium (os) was found to be the most toxic in the test while boron (b), the least toxic. the ec(50) values of this study revealed positive linear relationship with the established test models of cladoceran (daphnia magna), sludge worm (tubifex tubi ... | 2009 | 19683870 |
| complete life cycle of myxobolus rotundus (myxosporea: myxobolidae), a gill myxozoan of common bream abramis brama. | the life cycle of myxobolus rotundus nemeczek, 1911, a myxosporean parasite of the gills of common bream abramis brama l., was studied under laboratory conditions. mature myxobolus spp. spores from plasmodia in the gills of wild bream were used to infect naïve oligochaete worms in a flow-through system of aquaria. triactinomyxon-type actinospores were released from the oligochaetes 1 yr later and allowed to continually flow into a tank containing uninfected bream fry. the gills of the fry were c ... | 2009 | 19694174 |
| risk of myxobolus cerebralis infection to rainbow trout in the madison river, montana, usa. | myxobolus cerebralis, the parasite that causes salmonid whirling disease, has had detrimental effects on several salmonid populations in the intermountain west, including the rainbow trout in the madison river, montana, usa. the goal of this study was to examine relationships among characteristics of the environment, tubifex tubifex (the alternate host) populations, and rainbow trout whirling disease risk in the madison river. environmental characteristics were measured in side channels of the m ... | 2006 | 16711061 |
| assimilation efficiencies of cd and zn in the common carp (cyprinus carpio): effects of metal concentration, temperature and prey type. | the impact of several factors on the assimilation efficiency (ae) of cd and zn from food in the common carp (cyprinus carpio) was studied. tested prey species were midge larvae (chironomus riparius), zebra mussels (dreissena polymorpha) and oligochaetes (tubifex tubifex). the cd load of the larvae did not affect the cd ae in the carp. the zn ae however, was negatively related to the zn load of the prey. food quantity and starvation of the carp did not significantly affect the cd ae. for zn, a si ... | 2007 | 16764974 |
| sediment quality in rio guadiamar (sw, spain) after a tailing dam collapse: contamination, toxicity and bioavailability. | an integrated assessment of sediment quality in the guadiamar river after a mining spill was conducted. the concentration of different metals and other conventional parameters were measured in sediments located along the river. four sediment toxicity tests (hyalella azteca 28-day survival and growth test; chironomus riparius 10-day survival and growth test; hexagenia spp. 21-day survival and growth test; and tubifex tubifex 28-day reproduction and survival test) were carried out to determine the ... | 2006 | 16820209 |
| mycobacteriosis in mangrove killifish (rivulus magdalenae) caused by living fish food (tubifex tubifex) infected with mycobacterium marinum. | mycobacterium marinum was demonstrated in the mud tube worm tubifex tubifex. these worms served as live fish food for aquarium fishes. the ingestion of tubifex tubifex by the mangrove killifish rivulus magdalenae, a neotropical species in the order cyprinodontiformes, was the source of an atypical mycobacteriosis of these fishes. | 2006 | 16856609 |
| effects of chitosan on oxidative stress and metallothioneins in aquatic worm tubifex tubifex (oligochaeta, tubificidae). | chitosan is a natural polymer which has the property to elicit the natural defenses mechanism in plant and which can be an interesting biopesticides. it is then necessary to investigate the potential toxicity of chitosan for aquatic animal health. metallothioneins (mts) are low molecular weight proteins, mainly implicated in metal ion detoxification. increase in mts contents had been considered as a specific biomarker of metal exposure. however recently it has been demonstrated that mts particip ... | 2007 | 17187843 |
| [rapid inactivation mechanism of copper to tubifex tubifex and its application analysis in water plant]. | the fluctuation of *oh concentration in tubifex tubifex exposed to copper was investigated by fluorospectrophotometry using terephthalic acid (ta) as *oh trapping agent. catalase (cat) activity in t. tubifex was quantified after 30 minutes contact with copper. inactivation effect and lipid peroxidation produce malondialderhyde (mda) of t. tubifex were also studied. results showed that copper had significant inactivation effect on t. tsubifex. 100% inactivation efficiency was obtained when copper ... | 2010 | 20391698 |
| effect of cadmium on the susceptibility of tubifex tubifex to myxobolus cerebralis (myxozoa), the causative agent of whirling disease. | environmental pollutants alter a wide range of host-parasite interactions in various ways. in some cases, pollution leads to a significant increase in parasite abundance, causing epidemics of parasitic diseases. in other cases, toxicants restrict the transmission success of parasites, resulting in reduction of their abundance. however, very little is known regarding whether and to what extent aquatic pollution affects myxozoan obligate parasites commonly found in fish. we investigated the effect ... | 2010 | 20391913 |
| molluscan death effector domain (ded)-containing caspase-8 gene from disk abalone (haliotis discus discus): molecular characterization and expression analysis. | the caspase family represents aspartate-specific cysteine proteases that play key roles in apoptosis and immune signaling. in this study, we cloned the first death effector domain (ded)-containing molluscan caspase-8 gene from disk abalone (haliotis discus discus), which is named as hdcaspase-8. the full-length hdcaspase was 2855 bp, with a 1908 bp open reading frame encoding 636 amino acids. the hdcaspase-8 had 72 kda predicted molecular mass with an estimated isoelectric point (pi) of 6.0. the ... | 2010 | 21130887 |
| extrapolation of toxic indices among test objects. | oligochaeta tubifex tubifex, fish fathead minnow (pimephales promelas), hepatocytes isolated from rat liver and ciliated protozoan are absolutely different organisms and yet their acute toxicity indices correlate. correlation equations for special effects were developed for a large heterogeneous series of compounds (qsar, quantitative structure-activity relationships). knowing those correlation equations and their statistic evaluation, one can extrapolate the toxic indices. the reason is that a ... | 2010 | 21331180 |
| prevalence of myxobolus cerebralis infections among genetic lineages of tubifex tubifex at three locations in the madison river, montana. | abstract host biodiversity can impact disease risk and influence the transmission of parasitic disease. stream sediment-dwelling worms, tubifex tubifex (clitellata: oligochaeta), are the definitive host of the parasite myxobolus cerebralis (myxozoa: myxosporea), which causes whirling disease in salmonid fishes. genetic diversity of t. tubifex is correlated with host susceptibility to m. cerebralis , and mitochondrial lineage iii is generally shown to be more likely to be infected and produce the ... | 2011 | 21506853 |
| comparative susceptibility of deschutes river, oregon, tubifex tubifex populations to myxobolus cerebralis. | dams along the deschutes river (dr) in central oregon have blocked fish migration for over 40 years. reestablishment of anadromous fish runs above the dams as part of a fish passage plan may introduce fish pathogens, such as myxobolus cerebralis, the myxozoan parasite that causes salmonid whirling disease. this parasite is carried by adult salmon that stray into the dr system during their return to enzootic areas of the upper columbia river basin, and it is now known to be established in at leas ... | 2011 | 21699131 |
| the parasite that causes whirling disease, myxobolus cerebralis, is genetically variable within and across spatial scales. | understanding the genetic structure of parasite populations on the natural landscape can reveal important aspects of disease ecology and epidemiology and can indicate parasite dispersal across the landscape. myxobolus cerebralis (myxozoa: myxosporea), the causative agent of whirling disease in the definitive host tubifex tubifex, is native to eurasia and has spread to more than 25 states in the usa. the small amounts of data available to date suggest that m. cerebralis has little genetic variabi ... | 2011 | 22151695 |
| determination of anthelmintic activity of the leaf and bark extract of tamarindus indica linn. | the aim of the present study was to evaluate the anthelmintic activity of ethanolic and aqueous extract of leaves and bark of tamarindus indica linn using pheretima posthuma and tubifex tubifex as test worms. the time of paralysis and time of death were studied and the activity was compared with piperazine citrate as reference standard. the alcohol and aqueous extract of bark of tamarindus indica exhibited significant anthelmintic activity as evidenced by decreased paralyzing time and death time ... | 2011 | 22131633 |
| rearing and estimation of life-cycle parameters of the tubicifid worm branchiura sowerbyi: application to ecotoxicity testing. | this paper provides original collection, acclimatizing, rearing and toxicity test methods for the freshwater worm branchiura sowerbyi, an alternative species to tubifex tubifex for ecotoxicity evaluation of sediments. influence of the substrate, type of food, and feeding level on individual performances was assessed in short-term tests, in order to set up optimal culture and test conditions. low-size particles and high organic matter content favoured the growth and reproduction of b. sowerbyi. t ... | 2007 | 17614123 |
| comparison of tributyltin compound effects on the alga scenedesmus quadricauda and the benthic organisms tubifex tubifex and chironomus plumosus. | the inhibitory and toxic effects of five tributyltin compounds and one dibutyltin compound were determined under standardized conditions on the freshwater plankton alga scenedesmus quadricauda and the benthic organisms tubifex tubifex and chironomus plumosus. observed were the mortality of benthos after 96 h and the inhibition of growth, photosynthesis, and chlorophyll a content of the alga after 12 days of cultivation. the effects of the compounds were expressed as lc50 values for mortality and ... | 1998 | 9799573 |
| comparative study of ecotoxicological effect of triorganotin compounds on various biological subjects. | the toxic and inhibitory effect of 10 triorganotin compounds (triphenlyl-, tribenzyl-, and tributyltins) were determined under standardized conditions on four biological subjects: tubifex tubifex, chironomus plumosus, sinapis alba seeds, and the alga scenedesmus quadricauda. observed were the mortality of t. tubifex and ch. plumosus after 96 hr, the root growth inhibition of s. alba seeds after 72 hr, and the inhibition of growth, photosynthesis, and chlorophyll a content of s. quadricauda after ... | 1997 | 9056398 |
| the role of tubificid worms as an intermediate host in the life cycle of myxobolus pavlovskii (akhmerov, 1954). | myxobolus pavlovskii from the gills of silver carp (hypophthalmichthys molitrix) were used in attempts to transmit the infection under laboratory conditions. spores of m. pavlovskii were placed in aquaria that contained sterilized sand and had been filled with tap water at 15-16 degrees c. furthermore, oligochaetes (90% tubifex tubifex) were added and examined by wet mounts and histology. hexactinomyxon spores developed after about 3 months only in t. tubifex that had been exposed to m. pavlovsk ... | 1991 | 1805209 |
| primary rat hepatocytes in chemical testing and qsar predictive applicability. | primary rat hepatocytes were used to test acute toxicities of 16 neutral aliphatic alcohols, ketones and esters. their effects on cell viability and metabolic function (ureogenesis, i.e. biotransformation of ornithine to urea) were measured and expressed as ec50 values. log ec50 values from both tests correlated with the log partition coefficients for the chemicals between n-octanol and water and log p(ow)-based qsar models were derived. log ec50 (viability) tightly correlates with log ec50 (ure ... | 2010 | 19735719 |
| epizootiology of myxobolus cerebralis, the causative agent of salmonid whirling disease in the rock creek drainage of west-central montana: 2004-2008. | whirling disease, caused by the myxozoan parasite myxobolus cerebralis , remains a serious health threat to salmonid fish in the western united states. a previously published study on the epizootiology of whirling disease in the rock creek watershed of west-central montana, conducted from 1998 to 2003, showed that the intensity of m. cerebralis infections in sentinel trout increased significantly throughout the drainage and that the range of m. cerebralis had expanded considerably. in addition, ... | 2010 | 19891515 |
| bridging levels of pharmaceuticals in river water with biological community structure in the llobregat river basin (northeast spain). | a wide range of human pharmaceuticals are present at low concentrations in freshwater systems, particularly in sections of polluted river. these compounds show high biological activity, often associated with a high stability. these characteristics imply a potential impact of these substances on aquatic biota even when present at low environmental concentrations. low flow conditions in mediterranean rivers, most of which flow through densely populated areas and are subjected to intensive water us ... | 2009 | 19908929 |
| comparative study of plant growth hormone (herbicide) toxicity in various biological subjects. | due to their widespread distribution and toxic nature, herbicides may have a serious impact on the environment and exert adverse effects on associated organisms. the present study was conducted to determine the acute toxicological effects of some plant growth hormones used as herbicides on four biological subjects and compare the subjects' sensitivity to individual testing substances. the herbicides 4-(indol-3-yl)acetic acid c10h9o2n (iaa), n6-(beta 2-isopentenyl)adenosine (pi-indolylpropionic a ... | 1994 | 7534692 |
| toxicity of metals on daphnia magna and tubifex tubifex. | the toxicity of hg2+ [hgcl2], cr6+(1) [(nh4)2cro4], cr6+(2) [cro3], cd2+ [cdcl2.2,5h2o], pb2+ [pb(ch3coo)2.3h2o], and as5+ [na2haso4.7h2o] on the sensitivity and survival of daphnia magna and tubifex tubifex has been studied. all test metals were dissolved and determined under standardized conditions (dilution water, bringmann and kühn, 1982) and 96 hr lc50 for t. tubifex and 48 hr lc50 for d. magna were compared in rank orders toxicity. for d. magna rank order toxicity was hg2+ > cr6+(2) > cd2+ ... | 1994 | 7516286 |
| improving sediment-quality guidelines for nickel: development and application of predictive bioavailability models to assess chronic toxicity of nickel in freshwater sediments. | within the framework of european union chemical legislations an extensive data set on the chronic toxicity of sediment nickel has been generated. in the initial phase of testing, tests were conducted with 8 taxa of benthic invertebrates in 2 nickel-spiked sediments, including 1 reasonable worst-case sediment with low concentrations of acid-volatile sulfide (avs) and total organic carbon. the following species were tested: amphipods (hyalella azteca, gammarus pseudolimnaeus), mayflies (hexagenia ... | 2013 | 23983116 |
| chronic toxicity of nickel-spiked freshwater sediments: variation in toxicity among eight invertebrate taxa and eight sediments. | this study evaluated the chronic toxicity of ni-spiked freshwater sediments to benthic invertebrates. a 2-step spiking procedure (spiking and sediment dilution) and a 2-stage equilibration period (10 wk anaerobic and 1 wk aerobic) were used to spike 8 freshwater sediments with wide ranges of acid-volatile sulfide (avs; 0.94-38 µmol/g) and total organic carbon (toc; 0.42-10%). chronic sediment toxicity tests were conducted with 8 invertebrates (hyalella azteca, gammarus pseudolimnaeus, chironomus ... | 2013 | 23657897 |
| observation of large, non-covalent globin subassemblies in the approximately 3600 kda hexagonal bilayer hemoglobins by electrospray ionization time-of-flight mass spectrometry. | a non-covalent globin subassembly comprising 12 globin chains (204 to 214 kda) was observed directly by electrospray ionization time-of-flight mass spectrometry in the native hexagonal bilayer hemoglobins from the oligochaetes lumbricus terrestris and tubifex tubifex, the polychaetes tylorrhynchus heterochaetus, arenicola marina, amphitrite ornata and alvinella pompejana, the leeches macrobdella decora, haemopis grandis and nephelopsis oscura and the chlorocruorin from the polychaete myxicola in ... | 2001 | 11397079 |
| subcellular distribution of cd in the aquatic oligochaete tubifex tubifex, implications for trophic availability and toxicity. | we studied the compartmentalization of cadmium and zinc in the oligochaete tubifex tubifex. the subcellular distribution was followed over time and levels of metallothionein-like proteins were measured. the impact of the speciation on the trophic transfer was studied by calculating the assimilation efficiencies of metals from tubificidae fed to carp. it was found that carp were able to assimilate 9.8% of the cadmium. the expected assimilated amount of cadmium, based on the subcellular fractions ... | 2007 | 17240028 |