developmental expression of surface antigen genes in the parasitic ciliate ichthyophthirius multifiliis.a 1.2-kilobase (kb) cdna encoding a major surface antigen of the holotrich ciliate ichthyophthirius multifiliis (an obligate parasite of fish) has been isolated and used as a probe to examine the expression of immobilization antigen (i-antigen) genes in this system. the cdna encodes a predicted protein of 394 amino acids with a tandemly repeated structure characteristic of the i-antigens of the related free-living ciliates paramecium and tetrahymena. as shown by northern hybridization analysis w ...19921631132
production and preliminary characterization of murine monoclonal antibodies to ichthyophthirius multifiliis, a protozoan parasite of initial panel of 34 hybridomas, each secreting antibodies reactive with an infective theront stage of an ichthyophthirius multifiliis isolate, was produced. three of these cell lines, each producing immunoglobulin m class antibodies, were cloned by limiting dilution and were expanded as ascites-producing tumors in syngeneic mice. three monoclonal antibodies (mab) reacted with intact whole theronts in an enzyme-linked immunosorbent assay to dilutions of 1:10,000 in ascitic fluids and had a sim ...19862431637
[the immunological reactions of fishes to parasite infection under different temperature conditions].the dependence of immunological reactions of fishes infected with ichthyophthirius multifiliis infusoria was elucidated. the invasion of the parasite results in the activation of the immune system, increased phagocytosis and a growth of the activity of oxydase enzymes. with the increased number and sizes of parasites a decrease of the above parameters below the control values is observed. changes of the immunological values are most dynamic at high (20-25 degrees) and they are slower at low (10 ...19902120670
antiprotozoan activity of nonspecific cytotoxic cells (ncc) from the channel catfish (ictalurus punctatus).nonspecific cytotoxic cells (ncc) obtained from channel catfish (ictalurus punctatus) kill tetrahymena pyriformis, an opportunistic parasite in fish. based upon this fact, a new mechanism for nonspecific cellular anti-parasitic immunity in fish is proposed. optimum in vitro conditions for ncc killing of deciliated t. pyriformis were first obtained. lysis of t. pyriformis by ncc occurred by 10 hr of cocultivation of effector and target cells. during this time period, 50 to 60% cytotoxicity occurr ...19852578055
treatment of fish parasites. 9. effects of a medicated food containing malachite green on ichthyophthirius multifiliis fouquet, 1876 (hymenostomatida, ciliophora) in ornamental fish.for systemic therapy against trophozoites of the skin-inhabiting stage of ichthyophthirius multifiliis in ornamental fish, the latter were fed medicated food flakes containing malachite green once daily for 1-11 days ad libitum. naturally or artificially infected cardinal tetras (paracheirodon axelrodi), blue gouramis (trichogaster trichopterus), or clown loach (botia macracantha) were used in the trials. the fish were maintained in aerated 12.5- or 60-1 aquaria at 23 degrees c. ultrastructural ...19921589426
ichthyophthirius multifiliis (ciliophora) exit from gill epithelium.the first change in the sequence of morphological events occurring as fully developed ichthyophthirius multifiliis trophonts spontaneously left gill epithelium or as younger trophonts departed, following experimentally induced death of the fish, was the separation of parasites from overlying host cells. discharge of contractile vacuoles may have played a role in this process. spaces then appeared between host cells, and individual epithelial cells became vacuolated. finally, the epithelium ruptu ...19873116222
the cellular proliferative response, humoral antibody response, and cross reactivity studies of tetrahymena pyriformis with ichthyophthirius multifiliis in juvenile carp (cyprinus carpio l.).the immune response of 10-12-week-old juvenile carp to t. pyriformis [ccap 1630/w, 1939 (w)] was investigated. the humoral antibody response following one and two intraperitoneal injections of whole live t. pyriformis (protein concentration of 25 micrograms/g body weight), separated by an interval of 4 weeks, was monitored over 12-16 weeks. peak antibody titres were detected 6 weeks following antigen administration. antibody titres were elevated following the second injection, and relatively hig ...19921505691
ichthyophthirius (ciliophora): population studies suggest reproduction in host epithelium.evidence that ichthyophthirius multifiliis trophonts may reproduce within the epithelium of the host was obtained from experimental infections of channel catfish. mean number of parasites spontaneously leaving the fish increased from 0 on day 3 postexposure (pe) to 66.5 per fish on day 7 pe. mean population density in fin, however, increased five-fold from day 3 to day 5 pe in the absence of opportunity for reinfection. at day 3 pe, 100% of parasite loci in fin and gill arches contained solitary ...19883143828
[human pathogenicity of ichthyophthirius multifiliis]. 19694987193
[ultra-fine structure of the nuclear apparatus of ichthyophthirius multifiliis at the cystal stage in protomites]. 19684989386
icthyophthirius multifiliis has membrane-associated immobilization antigens.sera from fish that survive infections with the ciliated protozoon, ichthyophthirius multifiliis, immobilize the parasite in vitro. in order to identify cell surface antigens involved in the immobilization response, integral membrane proteins were extracted from tomites with triton x-114 and used to immunize rabbits. the rabbit antisera immobilized the parasite in vitro and antigens were localized to cell and ciliary plasma membranes by indirect immunofluorescent microscopy. the membrane protein ...19892470899
ascorbic acid induced immune-mediated decrease in mortality in ichthyophthirius multifiliis infected rainbow-trout (salmo gairdneri). 19862877556
[occurrence and significance of ichthyophthirius multifiliis in switzerland]. 19873109029
sublethal copper stress and susceptibility of channel catfish to experimental infections with ichthyophthirius multifiliis. 19826809081
enzyme cytochemistry of the alveolar sacs and golgian-like cisternae in the ciliate ichthyophthirius the cell cortex of the parasitic ciliate ichthyophthirius multifiliis different kinds of cisternae were observed: the alveolar sacs, thick membrane cisternae and the endoplasmic reticulum. the thick membrane cisternae possess coated dilated rims and sometimes could be observed close to the endoplasmic reticulum. using cytochemical techniques acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in the thick membrane cisternae and in the alveolar sacs ...19902162959
localized leucocyte response to ichthyophthirius multifiliis establishment in immune carp cyprinus carpio l.o-group carp (cyprinus carpio) which had been immunized against ichthyophthirius multifiliis by controlled infections were challenged by topical application of theronts to the caudal fin. the parasites which established were examined ultrastructurally, and host leucocyte responses were compared with those observed in primary infections. in the primary exposure group eosinophils and (to a lesser extent) basophils were the predominant cells infiltrating infection sites. in contrast, parasite devel ...19938291210
relationships between the parasites of some wild and cultured fishes in two lakes and a fish farm in central finland.a total of 526 atlantic salmon and 500 brown trout from a fish farm were studied for parasites, as were 272 roach, 251 perch and 150 whitefish from the lake which formed the water source, and 196 roach and 136 perch from the effluent recipient lake. the cultured fish harboured 14 parasite species, of which most were protozoan generalist parasites. nine species were found on salmon and 12 on brown trout. epizootically the most important species were ichthyobodo necator, chilodonella cyprini and i ...19948021098
[changes in the electrolyte composition of the blood and muscles in carp infection with ichthyophthirius multifiliis (ciliata, ophryoglenidae)].a study of the electrolytic contents of blood serum, erythrocytes and muscles of carp infected with ichthyophthirius multifiliis was carried out. whatever the infection intensity, a characteristic increase in the cations k+ and na+ ratio in the plasma and muscles of infected fishes takes place. the above dependence, which is expressed in the intensification of active ions transport, is associated with mobilization of organism's protective functions.19846441141
processing of food vacuoles in the parasitic ciliate ichthyophthirius multifiliis after exit from the host.the digestive cycle of the fish parasite ichthyophthirius multifiliis (ciliophora) can be divided into three main stages. during stage a the vacuoles are not yet condensed. this stage can be subdivided into an early phase in which food vacuoles contain almost intact fish cells and a later phase in which dense material accumulates at the periphery of the vacuoles. at stage b, food vacuoles attain a very high density, and at stage c the vacuole expands when the membrane pulls away from a condensed ...19938327449
[the population level and distribution of ectoparasites in carp].the abundance and the distribution of dactylogyrus extensus and ichthyophthirius multifiliis on gills of two-years old carps have been investigated. it has been established that at least there are five groups, which differs from each other on the asymmetry of infection.19938488057
[attempt of cultivation in vitro of ichthyophthirius multifiliis fouquet]. 19674866640
[on the structure of the macronucleus of the parasitic infusoria ichthyophthirius multifiliis]. 19674989011
passive immunization of channel catfish (ictalurus punctatus) against the ciliated protozoan parasite ichthyophthirius multifiliis by use of murine monoclonal acquire immunity against the ciliated protozoan parasite ichthyophthirius multifiliis following sublethal infection. the immune response includes the elaboration of humoral antibodies against a class of abundant surface membrane proteins referred to as immobilization antigens (i-antigens). antibodies against these proteins immobilize the parasite in vitro, suggesting a potential role for the i-antigens in protective immunity. to test this hypothesis, passive immunization experiments were ca ...19968926073
phylogeny of the fish parasite ichthyophthirius and its relatives ophryoglena and tetrahymena (ciliophora, hymenostomatia) inferred from 18s ribosomal rna sequences.phylogenetic relationships within the subclass hymenostomatia were inferred from the comparisons of three new ssrrna gene sequences from ichthyophthirius multifiliis (1,751 bp), ophryoglena catenula (1,748 bp), and tetrahymena corlissi (1,753 bp). using maximum-parsimony and distance-matrix methods, ichthyophthirius and ophryoglena were consistently paired and formed a sister group to the tetrahymenines, consistent with their placement in the ophryoglenina. tetrahymenids formed a monophyletic gr ...19957700154
the control of ichthyophthiriasis by a medicated food containing quinine: efficacy tests and ultrastructure investigations.the present report demonstrates that a medicated food containing quinine kills the skin-inhabiting trophozoite stage of ichthyophthirius multifiliis in ornamental fish. artificially infected swordtails. (xiphophorus helleri), black mollies (poecilia sphenops), and black neons (hyphessobrycon herbertaxelrodi) were used in the trials. the fish were maintained in groups of 10 or 20 inside aquaria (20 or 60 l) at 25 degrees c. ultrastructure investigations by means of transmission electron microscop ...19968897504
sustained growth of ichthyophthirius multifiliis at low temperature in the laboratory.applied and basic research on the ciliate ichthyophthirius multifiliis, an obligate parasite of freshwater fishes, requires passage on fish hosts to maintain laboratory stocks. however, continual repeated passage results in senescence of parasite clones over time. because growth and development are directly correlated to water temperature, our objective was to grow the parasite at low temperature in order to extend the period that the organism remains on the fish, thus reducing: (1) the number o ...19958544046
ichthyophthirius multifiliis: a model of cutaneous infection and immunity in fishes.the parasitic ciliate ichthyophthirius multifiliis offers a useful system for the study of cutaneous immunity against an infectious microorganism. naive fish usually die following infection, but animals surviving sublethal parasite exposure become resistant to subsequent challenge. this resistance correlates with the presence of humoral antibodies in the sera and cutaneous mucus of immune fish. a mechanism of immunity has recently been elucidated that involves antibody binding to surface protein ...19989914927
epizootiology of protozoans in farmed salmonids at northern latitudes.protozoan ectoparasites were examined in a northern salmonid fish farm over a 10-year period, june 1984-may 1994, by the same researcher, with similar catching and sampling procedures throughout. husbandry procedures remained constant during the study, e.g., fingerlings were kept in steel tanks and yearlings in both steel tanks and earth ponds. ichthyobodo necator, chilodonella hexasticha and ichthyophthirius multifiliis infections were treated with formalin, salt and malachite green-formalin ba ...19979076534
ultrastructural and cytochemical identification of peroxisomes in the ciliate ichthyophthirius multifiliis.the peroxisomes of the parasitic ciliate ichthyophthirius multifiliis were studied, using ultrastructural and cytochemical techniques. in this ciliate most peroxisomes possess a circular or oval section less than 0.6 micron in diameter. however, some dumbbell-shaped and elongated peroxisomes could also be observed. these organelles were frequently associated with the mitochondria and were more abundant in the cell cortex than in the center of the ciliate. small vesicles and dense nucleoids were ...19938461889
experimental infection of striped marshfrog tadpoles (limnodynastes peronii) by ichthyophthirius multifiliis.ichthyophthirius multifiliis, or white spot, is a well known and widely distributed parasite of freshwater fish. however, it is not know whether it can infect other aquatic vertebrates such as amphibians. this study uses a series of laboratory-based experiments to demonstrate that i. multifiliis can infect the tadpole stage of an amphibian, the striped marshfrog (limnodynastes peronii) of eastern australia. the tadpoles did not appear to develop ichthyophthiriasis at low parasite levels (200 par ...199910386457
ichthyophthiriasis in carp cyprinus carpio: infectivity of trophonts prematurely exiting both the immune and non-immune host.ichthyophthirius multifiliis exposed to naturally immunised carp established short-term infections, the majority of parasites actively emerging within 2 h of entering the epidermis. a small, but significant, number of these expelled parasites were shown to retain theront-like properties with the capacity to directly re-invade a further fish host. infectivity fell rapidly with time in the host and was comparable to that of trophonts of a similar age artificially induced to emerge from non-immune ...199910401585
serotypic variation among isolates of ichthyophthirius multifiliis based on immobilization.efforts have been made to determine whether surface antigens could be used as biochemical markers to define strain differences in the parasitic ciliate ichthyophthirius multifiliis. in previous studies, a wild-type isolate designated g1 was found to have surface proteins analogous to the immobilization antigens of paramecium and tetrahymena; rabbit antiserum against this strain immobilizes homologous cells in vitro. it has now been shown for two additional ichthyophthirius isolates (designated g ...19938293000
parasite infections in danish trout farms.samples from 5 danish freshwater trout farms rearing rainbow trout (oncorhynchus mykiss) were examined for parasite infections from october 1993 until november 1994 and recorded parasites are listed. in addition, results from an examination of a mariculture net cage system are presented as well. a total of 10 metazoan and 10 protozoan parasites were recorded. the metazoans included gyrodactylus derjavini, gyrodactylus salaris, eubothrium crassum, triaenophorus nodulosus, proteocephalus sp., dipl ...19957502946
chemoattraction of ichthyophthirius multifiliis (ciliophora) theronts to host molecules.mechanisms in the host-finding process of ichthyophthirius multifiliis were studied in vitro by a novel bioassay using 24-well multidishes supplied with bottom layers of agar with chemoattractants. it was shown that low molecular weight molecules (carbohydrates, amino acids, fatty acids, urea) did not attract theronts. in contrast, sera and mucus from a range of teleosts (including marine fish) were effective attractants. fractionation by gel filtration of fish serum allowed determination of the ...199910579427
occurrence of ichthyophthirius multifiliis within the peritoneal cavities of infected channel catfish ictalurus punctatus.ichthyophthirius multifiliis is a ciliated protozoan parasite that infects the skin and gills of freshwater fish. this report describes the unusual finding of i. multifiliis within the peritoneal cavities of experimentally infected channel catfish ictalurus punctatus. twenty catfish fingerlings were exposed to i. multifiliis theronts using a standardized protocol. five infected fish and 2 control fish were killed at various time points after infection and their tissues examined. formalin-fixed, ...200111253873
prolonged in vitro cultivation of ichthyophthirius multifiliis using an epc cell line as substrate.the ciliate ichthyophthirius multifiliis, which normally requires a fish host to develop from the theront stage to the trophont stage, was cultivated in vitro for part of its life cycle. experiments were conducted using a laboratory strain of the parasite originally isolated from rainbow trout oncorhynchus mykiss in a danish trout farm. theronts escaping from tomontocysts were kept in water, cell culture media (e-mem or l-15), or cultures of epc (epithelioma papulosum cyprini) cells in plastic t ...200011104073
immunization against parasitic diseases of fish.parasitologists have not, in the past, exploited the immune system to protect fish against parasitic diseases. in the past few years, however, there has been an increased interest in adopting this strategy, and we have made steady and promising progress against a few parasites which are of economic importance. amyloodinium ocellatum is an ectoparasitic dinoflagellate on brackish and marine fishes, which may also cause problems to aquarium fishes. antiserum from fish inoculated intraperitoneally ...19979270852
partial cross protection against ichthyophthirius multifiliis in gyrodactylus derjavini immunized rainbow trout.partial cross protection against a skin-parasitic ciliate has been recorded in rainbow trout previously immunized with an ectoparasitic platyhelminth. the susceptibility to infection by ichthyophthirius multifiliis differed significantly between naive and gyrodactylus derjavini immunized rainbow trout. fish partly immune to the ectoparasitic monogenean g. derjavini became less infected and experienced lower mortality than naive fish when exposed to i. multifiliis infections. in vitro studies on ...199910526411
effect of lectins on the invasion of ichthyophthirius theront to channel catfish tissue.this study determined the effects of lectin binding to theronts of ichthyophthirius multifiliis on theront immobilization, invasion, trophont development and survival in channel catfish ictalurus punctatus excised fins in vitro. soybean agglutinin (sba), lentil agglutinin (lca), gorse agglutinin (uea-i) and wheat germ agglutinin (wga) were used to treat theronts. percentages of theronts immobilized by 4 lectins ranged from 12.0 to 19.4% at a concentration of 1000 microg ml(-1). these lectins bou ...200111463098
host responses against the fish parasitizing ciliate ichthyophthirius multifiliis.recent studies have shown that fish are able to mount protective immune responses against various parasites. one of the best characterized parasite-host system in this context is the ciliate ichthyophthirius multifiliis (ich) parasitizing a range of freshwater fishes. both specific and non-specific host defence mechanisms are responsible for the protection of fish against challenge infections with this ciliate. the specific humoral components comprise at least specific antibodies. the non-specif ...200111522410
a robust inducible-repressible promoter greatly facilitates gene knockouts, conditional expression, and overexpression of homologous and heterologous genes in tetrahymena thermophila.the cd(2+)-inducible metallothionein (mtt1) gene was cloned from tetrahymena thermophila. northern blot analysis showed that mtt1 mrna is not detectable in the absence of cd(2+), is induced within 10 min of its addition, is expressed in proportion to its concentration, and rapidly disappears upon its withdrawal. similarly, when the neo1 gene coding region flanked by the mtt1 gene noncoding sequences was used to disrupt the mtt1 locus, no transformants were observed in the absence of cd(2+), and ...200211891286
variation in primary sequence and tandem repeat copy number among i-antigens of ichthyophthirius multifiliis.the immobilization antigens (i-antigens) of ichthyophthirius multifiliis are potential vaccine candidates for the prevention of 'white spot' disease in freshwater fish. these antigens vary with respect to antigenicity and molecular mass, and at least five i-antigen serotypes have been identified among parasite isolates thus far. in previous studies, the gene and corresponding cdna encoding a approximately 48 kda i-antigen from parasite isolate g1 (serotype a), had been cloned and sequenced. we n ...200211849709
the i-antigens of ichthyophthirius multifiliis are gpi-anchored proteins.the parasitic ciliate ichthyophthirius multifiliis has abundant surface membrane proteins (i-antigens) that when clustered, trigger rapid, premature exit from the host. similar antigens are present in free-living ciliates and are gpi-anchored in both paramecium and tetrahymena. although transmembrane signalling through gpi-anchored proteins has been well-documented in metazoan cells, comparable phenomena have yet to be described in protists. since premature exit of ichthyophthirius is likely to ...200111411842
comparing tolerance of ichthyophthirius multifiliis and tetrahymena thermophila for new cryopreservation methods.ichthyophthirius multifiliis is an obligate protozoan parasite of freshwater fishes that has a complex developmental cycle. it has not been successfully cryopreserved, so management studies are restricted to parasites obtained during outbreaks or perpetuated by passage in live fishes. to overcome this serious limitation, free-swimming i. multifiliis parasites were tested in a cryopreservation protocol routinely used for a related ciliate, tetrahymena. in this protocol, i. multifiliis theronts re ...200212053978
the use of synthetic genes for the expression of ciliate proteins in heterologous systems.the common fish parasite, ichthyophthirius multifiliis, expresses abundant glycosylated phosphatidylinositol (gpi)-anchored membrane proteins known as immobilization antigens, or i-antigens. these proteins are targets of the host immune response, and have been identified as potential candidates for recombinant subunit vaccine development. nevertheless, because ichthyophthirius utilizes a non-standard genetic code, expression of the corresponding gene products, either as subunit antigens in conve ...200212034497
efficacy of selected oral chemotherapeutants against ichthyophthirius multifiliis (ciliophora: ophyroglenidae) infecting rainbow trout oncorhynchus mykiss.the chemotherapeutic efficacy of 6 in-feed compounds against ichthyophthirius multifiliis fouquet, 1876 was assessed using experimental infections of rainbow trout oncorhynchus mykiss (walbaum) fingerlings. trial doses of 104 ppm amprolium hydrochloride or 65 ppm clopidol fed to fish for 10 d prior to infection significantly reduced the number of trophonts establishing in trout fingerlings by 62.0 and 35.2% respectively. in-feed treatments of infected trout with either 63 or 75 ppm amprolium hyd ...200312887250
parasitic infections in live freshwater tropical fishes imported to korea.we examined 15 species of ornamental tropical fishes originating from southeast asia to determine the cause of losses among 8 fish farms in korea. a total of 351 individuals belonging to 5 different families (1 species of characidae, 6 of cichlidae, 3 of cyprinidae, 1 of heleostomatidae, and 4 of poecilidae) were collected for the purpose of detecting metazoan and protozoan parasites. parasites were fixed and stained using routine methods, and identified. we found 3 ciliates, 2 monogeneans, 1 ne ...200212542094
systemic and cutaneous mucus antibody responses of channel catfish immunized against the protozoan parasite ichthyophthirius acquire protective immunity against the ciliated protozoan parasite ichthyophthirius multifiliis following sublethal infection or inoculation with i. multifiliis immobilization antigens (i-antigens). in both cases, parasite-immobilizing antibodies have been identified in sera and mucosal secretions. to investigate the kinetics of this immune response, antibody levels were determined by enzyme-linked immunosorbent assay (elisa) in the sera and cutaneous mucus of channel catfish (ictalurus pu ...200312965920
parasitic infections in freshwater ornamental fish in sri lanka.a total of 1520 ornamental fish of 13 species from 26 export farms in sri lanka were collected between october 1999 and march 2000 and examined for parasites. fish species examined were guppy poecilia reticulata, goldfish carassius auratus, platy xiphophorus maculatus, molly poecilia sphenops, angel pterophyllum scalare, swordtail xiphophorus helleri, tetras hyphessobrycon species, barbs capeota and puntius spp., gourami colisa sp., carp cyprinus carpio, fighters betta spelendens and others (bra ...200312747641
immunisation of channel catfish, ictalurus punctatus, with ichthyophthirius multifiliis immobilisation antigens elicits serotype-specific protection.surface immobilisation antigens (i-antigens) were purified from two strains of ichthyophthirius multifiliis (ny1 and g5) that represent different i-antigen serotypes, namely a and d, respectively. the efficacy of the purified antigens as subunit vaccines was then tested in challenge studies using parasites of the homologous or heterologous serotype. three groups of juvenile channel catfish (70 animals per group) were immunised with i-antigens from either the g5 or ny1 isolates, or with bovine se ...200212458741
effects of crude extracts of mucuna pruriens (fabaceae) and carica papaya (caricaceae) against the protozoan fish parasite ichthyophthirius multifiliis.the ciliate ichthyophthirius multifiliis is among the most pathogenic parasites of fish maintained in captivity. in the present study, the effects of the crude methanolic extract of leaves of mucuna pruriens and the petroleum-ether extract of seeds of carica papaya against i. multifiliis were investigated under in vivo and in vitro conditions. goldfish (carassius auratus auratus) infected with the parasites were immersed for 72 h in baths with m. pruriens extract, and for 96 h in baths with c. p ...200414735356
immune responses and host protection of channel catfish, ictalurus punctatus (rafinesque), against ichthyophthirius multifiliis after immunization with live theronts and sonicated trophonts.the humoral immune responses and host protection of channel catfish, ictalurus punctatus (rafinesque), against ichthyophthirius multifiliis (ich) were determined after immunization with live theronts and sonicated trophonts. immunizations with live theronts or sonicated trophonts were carried out by both bath immersion and intraperitoneal (i.p.) injection. cutaneous and serum immunoglobulin (ig) levels and anti-ich antibodies were measured 12 and 21 days post-immunization. the level of ich infec ...200415009239
protective effect of cutaneous antibody produced by channel catfish, ictalurus punctatus (rafinesque), immune to ichthyophthirius multifiliis fouquet on cohabited non-immune which survive a sublethal ichthyophthiriasis acquire protective immunity against ichthyophthirius multifiliis fouquet (ich). this study evaluated the protective effect of cutaneous antibody secreted by channel catfish, ictalurus punctatus (rafinesque), immune to ich on cohabited non-immune catfish. non-immune and immune fish controls were separately maintained and infected with theronts. the ich infection was assessed by scoring 0, < 50, 50-100, and > 100 trophonts fish(-1) at 5 days post-i ...200312962237
parasite communities as indicators of recovery from pollution: parasites of roach (rutilus rutilus) and perch (perca fuviatilis) in central finland.we compared parasite communities in fish taken from a polluted lake (l. vatia) and two control lakes before (1986) and after (1995) nine years of markedly reduced chemical and nutrient loading from a pulpmill in central finland. discriminant analyses of the 1995 data, using a function based on the 1986 data, showed that the parasite communities in the fish from the two control lakes had changed relatively little, whereas those from l. vatia had converged on those from the mesotrophic control lak ...200314667171
cadmium effects on ichthyophthirius: evidence for metal-sequestration in fish tissues following administration of recombinant vaccines.we are developing tetrahymena thermophila as a delivery system for recombinant vaccines against parasitic protozoa, including the common fish parasite, ichthyophthirius multifiliis. t. thermophila cell lines expressing i. multifiliis genes under the control of a cadmium-inducible metallothionein gene promoter conferred strong protection against a lethal parasite challenge when administered parenterally to naive fish. nevertheless, given that heavy metals can be toxic to parasites, a question aro ...200314667175
parasites in cultured and feral fish.parasites, causing little apparent damage in feral fish populations, may become causative agents of diseases of great importance in farmed fish, leading to pathological changes, decrease of fitness or reduction of the market value of fish. despite considerable progress in fish parasitology in the last decades, major gaps still exist in the knowledge of taxonomy, biology, epizootiology and control of fish parasites, including such 'evergreens' as the ciliate ichthyophthirius multifiliis, a causat ...199910456421
characterization of histone h3/h4 gene region and phylogenetic affinity of ichthyophthirius multifiliis based on h4 dna sequence variation.we sequenced the amino-terminal third of the histone h3 and h4 genes and the intergenic region from ichthyophthirius multifiliis. fourteen recombinant clones of 646 bp were sequenced and the level of sequence variation detected among these clones was similar to that reported among closely related species of tetrahymena and to levels of sequence variation detected within other ciliates. the intergenic region is 417 bp and approximately 92% at rich, making it the longest and most at-rich ciliate h ...200010712850
antibody-mediated effects on parasite behavior: evidence of a novel mechanism of immunity against a parasitic protist.the parasitic ciliate ichthyophthirius multifiliis is well known in commercial aquaculture as the etiological agent of 'white spot', a disease that afflicts a wide range of fresh-water fish. while ichthyophthirius is highly pathogenic, animals exposed to controlled infections develop a strong acquired resistance to the parasite. recent studies suggest host resistance involves a novel mechanism of humoral immunity affecting parasite behavior. rather than being killed, parasites are forced to exit ...199715275136
localized cellular responses to ichthyophthirius multifiliis: protection or pathogenesis?the ciliate ichthyophthirius multifiliis is an economically important parasite in aquaculture as well as in the ornamental fish trade. the parasite has been well studied and details of life cycle, host response and pathogenesis have been characterized. parasite development within host epithelial tissues initiates localized leukocytic infiltrations, although the relationship between these responses and host resistance is uncertain, and whether or not leukocyte responses play a role in protective ...199415275420
expression of pro-inflammatory cytokines in rainbow trout (oncorhynchus mykiss) during an infection with ichthyophthirius multifiliis.inflammatory processes are known to take place in the skin of fish during an infection with the parasitic ciliate ichthyophthirius multifiliis. the present study shows that the pro-inflammatory cytokines interleukin 1 beta (il-1beta) and tumor necrosis factor alpha (tnf-alpha), the chemokine interleukin 8 (il-8) and the type ii il-1 receptor (il-1rii) are expressed in rainbow trout during an infection. in the skin an up to 17.8 times increase in the expression level of il-1beta relative to uninf ...200415145419
influence of anguillicola crassus (nematoda) and ichthyophthirius multifiliis (ciliophora) on swimming activity of european eel anguilla anguilla.we investigated the swimming activity of 70 european eels anguilla anguilla in relation to natural infection with 2 parasite species: the eel-specific swimbladder nematode anguillicola crassus and the non-specific skin and gill protozoan ichthyophthirius multifiliis. we measured how long individual eels exposed to a water current in a swimming channel with a steady-stream profile could withstand the water current. the parasites affected the swimming behaviour of eels in different ways. the maxim ...200415460857
theronts of ichthyophthirius multifiliis find their fish hosts with complex behavior patterns and in response to different chemical parasites find and recognize fish hosts is best known for trematode cercariae. these multicellular organisms respond with complex behavior patterns to sequences of different chemical host signals, although these invasive stages are produced in large numbers. however, little is known on the host-finding of protozoan parasites. we therefore studied how the infective theronts of i. multifiliis find their fish hosts by offering them various fractions and chemical modifications of fish skin surfa ...199810622630
two year study on the infectivity of ichthyophthirius multifiliis in channel catfish ictalurus punctatus.ichthyophthirius multifiliis fouquet (ich) is a fish parasite that causes serious economic loss for aquaculture. a major difficulty in the maintenance of single isolates of ich for research purposes is the loss of infectivity. after an unknown number of passages or infection cycles the ich isolate loses its infectivity. this study determined the infectivity of an ich isolate during 105 infection cycles in channel catfish ictalurus punctatus over a 2 yr period. the mean percentage of fish infecte ...200415212279
non-invasive detection and quantification of the parasitic ciliate ichthyophthirius multifiliis by real-time pcr.the main parasitic threat to freshwater fish is the ciliate ichthyophthirius multifiliis. we developed a real-time pcr assay using sybr green intercalating fluorescent dye for rapid detection and quantification of i. multifiliis. this non-invasive assay was based on the quantification of i. multifiliis free-swimming stages from filtered water samples, and thus made it possible to preserve host individuals. an alignment of 18s rdna sequences of i. multifiliis and related species of the ciliate or ...200516119894
treatment of ichthyophthiriasis after malachite green. ii. earth ponds at salmonid farms.we tested formalin, chloramine-t-formalin and desirox-formalin, for use against white spot disease (ichthyophthiriasis) caused by ichthyophthirius multifiliis at 3 salmonid farms (salmo salar and s. trutta smolt reared in earth ponds). i. multifiliis disappeared from most individuals 4 to 5 wk after the first treatment (and after the first i. multifiliis were found) with all chemicals, indicating that combinations of these chemicals, and even formalin alone, can be used to lower the parasite bur ...200516175963
ichthyophthirius multifiliis fouquet and ichthyophthiriosis in freshwater teleosts.the ciliate ichthyophthirius multifiliis is an important pathogen of freshwater teleosts occurring in both temperate and tropical regions throughout the world. the disease, ichthyophthiriosis, accounts for significant economic losses to the aquaculture industry, including the ornamental fish trade, and epizootics in wild fish populations can result in mass kills. this review attempts to provide a comprehensive overview of the biology of the parasite, covering the free-living and parasitic stages ...200516182866
differences in virulence between two serotypes of ichthyophthirius multifiliis.naive channel catfish ictalurus punctatus were infected by 2 isolates of the parasitic ciliate ichthyophthirius multifiliis that differed in virulence. the isolates, ny1 and g5, serotypes a and d, respectively, express different surface immobilization-antigens. the virulence of the 2 isolates was compared using tail-fin infections to quantitate parasite numbers and by analysis of the survival of infected fish. although ny1 infected fish at a lower level than g5, all ny1-infected fish died, but 5 ...200616724566
real-time gene expression analysis in carp (cyprinus carpio l.) skin: inflammatory responses caused by the ectoparasite ichthyophthirius multifiliis.real time quantitative pcr (rq-pcr) assays were developed for the measurement of differential real-time expression of immune-related genes in skin and whole blood from cyprinus carpio during an infection with the ectoparasite ichthyophthirius multifiliis. the target genes included the chemokines cxca and cxcb, the chemokine receptors cxcr1 and cxcr2, the pro-inflammatory cytokines interleukin 1 beta (il-1beta) and tumour necrosis factor alpha (tnf-alpha) and the enzymes inducible nitric oxide sy ...200717046281
characterization of cryptocaryon irritans isolates from marine fishes in mainland china by its ribosomal dna isolates of cryptocaryon irritans from different host species and geographical locations in mainland china were characterized by the first (its-1) and second (its-2) internal transcribed spacers (its) of nuclear ribosomal dna (rdna) using two isolates of ichthyophthirius multifiliis for comparative purposes. the rdna region including the its-1, 5.8s, its-2, and flanking 18s and 28s sequences were amplified by polymerase chain reaction and the amplicons were sequenced directly. the its-1, 5 ...200616523350
ichthyophthirius multifiliis infection induces massive up-regulation of serum amyloid a in carp (cyprinus carpio).a real time quantitative pcr (rq-pcr) assay was developed for measurement of differential expression of the genes encoding the acute phase reactant serum amyloid a (saa), transferrin (tf) and a c-type lectin molecule (cl) in skin, blood and liver from cyprinus carpio following infection with the ectoparasite ichthyophthirius multifiliis. serum amyloid a and cl were constitutively expressed in all organs evaluated while tf transcripts were only detected in the liver. a dramatic up-regulation (160 ...200717095098
role of ichthyophthirius multifiliis in the infection of aeromonas hydrophila.aeromonas hydrophila and ichthyophthirius multifiliis are important fish pathogens. to clarify their relationship, two host models, goldfish with trauma and those infected with i. multifiliis, were used to study infection kinetics of a. hydrophila 4332 tagged with plasmid pgfpuv (ah4332(gfp)). the results showed that in fish suffering from ichthyophthiriosis, the bacterial infection process was accelerated and more persistent than in the other groups. it is suggested that i. multifiliis plays an ...200415330981
secretion of functional human enzymes by tetrahymena thermophila.the non-pathogenic ciliate tetrahymena thermophila is one of the best-characterized unicellular eucaryotes used in various research fields. previous work has shown that this unicellular organism provides many biological features to become a high-quality expression system, like multiplying to high cell densities with short generation times in bioreactors. in addition, the expression of surface antigens from the malaria parasite plasmodium falciparum and the ciliate ichthyophthirius multifiliis su ...200616542419
differential expression of cysteine proteases in developmental stages of the parasitic ciliate ichthyophthirius expressed sequence tag database of the freshwater fish parasite, ichthyophthirius multifiliis (ciliophora) was analyzed to seek for proteases potentially involved in the invasion and degradation of host tissues during infection. the translation of the database revealed two cathepsin l cysteine proteases (icp1 and icp2) of the c1a peptidase subfamily. the analysis of icp1 and icp2 sequences suggested that both proteases would be synthesized as preproproteins, with a mature domain of 27.9 and 2 ...200717227460
cutaneous immune responses in the common carp detected using transcript order to detect new immune-related genes in common carp (cyprinus carpio l.) challenged by an ectoparasitic infection, two cdna libraries were constructed from carp skin sampled at 3 and 72h after infection with ichthyophthirius multifiliis. in a total of 3500 expressed sequence tags (ests) we identified 82 orthologues of genes of immune relevance previously described in other organisms. of these, 61 have never been described before in c. carpio, thus shedding light on some key components of ...200717049603
invasion and development strategies of ichthyophthirius multifiliis, a parasitic ciliate of many other parasites, ichthyophthirius multifliis faces critical changes when moving between free-living and parasitic phases. this ciliate alternates between feeding in the epithelium of freshwater fishes and swimming and encysting in fresh water. several organelles appear to play key roles in successful negotiation o f these changes. margaret ewing and katherine kocan discuss a variety of cellular components important in host invasion and development of the parasite, with particular atten ...199215463617
differential transcription of multiple forms of alpha-2-macroglobulin in carp (cyprinus carpio) infected with parasites.alpha-2-macroglobulin (a2m) is a non-specific protease inhibitor involved in host defense mechanisms, inhibiting both endogenous and exogenous proteases. it is unique among the plasma anti-proteases with respect to the diversity of proteases that it can inactivate. carp a2m consists of an alpha and beta chain of which the first includes the bioactive regions. previously, three a2m alpha chain sequences were reported for east-asian common carp. we studied a2m alpha chain variability in european c ...200817662386
induced cross-protection in channel catfish, ictalurus punctatus (rafinesque), against different immobilization serotypes of ichthyophthirius multifiliis.abstract channel catfish, ictalurus punctatus (rafinesque), were immunized with ichthyophthirius multifiliis (ich) theronts and trophonts, and the immune response and host protection against both homologous and heterologous serotypes of ich were evaluated. immunizations were done with two immobilization serotypes (ars4 and ars6) of live theronts by bath immersion (trial i) and with sonicated trophonts by intraperitoneal (i.p.) injection (trial ii). cutaneous and serum antibody titres against ich ...200616533298
evaluation of a cohabitation challenge model in immunization trials for channel catfish ictalurus punctatus against ichthyophthirius multifiliis.calcein marking and cohabitation challenges have not been investigated in fish parasite research. this study evaluated a cohabitation challenge method in immunization trials against ichthyophthirius multifiliis (ich) using calcein, a fluorescent dye, to mark channel catfish ictalurus punctatus (rafinesque). fish were marked by calcein immersion at 0, 500, and 1500 mg l(-1), and then challenged with 15 000 theronts fish(-1). no difference was noted in fish infection levels, mortality, and mean da ...200717425263
generation and analysis of expressed sequence tags from the ciliate protozoan parasite ichthyophthirius multifiliis.the ciliate protozoan ichthyophthirius multifiliis (ich) is an important parasite of freshwater fish that causes 'white spot disease' leading to significant losses. a genomic resource for large-scale studies of this parasite has been lacking. to study gene expression involved in ich pathogenesis and virulence, our goal was to generate expressed sequence tags (ests) for the development of a powerful microarray platform for the analysis of global gene expression in this species. here, we initiated ...200717577414
cutaneous antibodies from channel catfish, ictalurus punctatus (rafinesque), immune to ichthyophthirius multifiliis (ich) may induce apoptosis of ich theronts.this study explored the existence of apoptosis (programmed cell death) in ichthyophthirius multifiliis fouquet (ich) theronts and determined the effect of cutaneous antibodies in skin culture fluid from fish immune to ich on theront apoptosis. apoptosis was detected in theronts and was clearly distinguished by fluorescent microscopy after staining with acridine orange and propidium iodide. the apoptotic theronts showed characteristic chromatin condensation and nuclear fragments containing chroma ...200515813863
efficacy of in-feed probiotics against aeromonas bestiarum and ichthyophthirius multifiliis skin infections in rainbow trout (oncorhynchus mykiss, walbaum).the aim of this study was to assess the efficacy of in-feed probiotics as a preventive measure against skin infections caused by aeromonas bestiarum and ichthyophthirius multifiliis (ich) in rainbow trout.200818422955
temperature-dependent protection against ichthyophthirius multifiliis following immunisation of rainbow trout using live theronts.rainbow trout oncorhynchus mykiss walbaum, 1792 fingerlings were vaccinated by intraperitoneal (i.p.) injection using live theronts of the skin parasitic ciliate ichthyophthirius multifiliis fouquet, 1876 at 2 temperatures (12 and 20 degrees c), and protection against challenge infections was subsequently evaluated by bath exposure to live theronts. vaccination conferred a relative protection (evaluated as the decrease in the number of established theronts) at 12 degrees c and almost complete im ...200617190205
protective immunity of nile tilapia against ichthyophthirius multifiliis post-immunization with live theronts and sonicated trophonts.two immunization trials were conducted to evaluate host protection of nile tilapia, oreochromis niloticus against ichthyophthirius multifiliis (ich). immunizations were done with live theronts or sonicated trophonts by bath immersion and intraperitoneal (ip) injection. the immunized fish were challenged with theronts 21 days post-immunization in trial i and 180 days post-immunization in trial ii. the serum anti-ich antibody and cumulative mortalities of tilapia were determined after theront chal ...200818442922
mtt2, a copper-inducible metallothionein gene from tetrahymena thermophila.metallothioneins (mts) are ubiquitous, cysteine-rich, metal-binding proteins whose transcriptional activation is induced by a variety of stimuli, in particular heavy metals such as cadmium, copper and zinc. here we describe the sequence and organization of a novel copper-inducible metallothionein gene (mtt2) from tetrahymena thermophila. based on its deduced sequence, the gene encodes a protein 108 amino acids, containing 29 cysteine residues (30%) arranged in motifs characteristic of vertebrate ...200818068524
treatment of ichthyophthiriasis in rainbow trout and common carp with common and alternative therapeutics.the goal of this laboratory study was to provide better knowledge about the treatment of ichthyophthiriasis (causative agent: ichthyophthirius multifiliis, a ciliate bacteria) in rainbow trout oncorhynchus mykiss and common carp cyprinus carpio. the following questions were investigated: (1) the effectiveness of different chemicals (formalin, sodium chloride, hydrogen peroxide, perotan, virkon, aquahumin, baycox, and ivomec) and at different concentrations and durations of application, (2) the n ...200718201060
cutaneous antibody-secreting cells and b cells in a teleost fish.antibodies in cutaneous mucus and skin of teleosts play a critical role in the protective immune response against infection. we demonstrate by elispot that antibody-secreting cells (asc), which include lps-inducible b cells (plasmablasts) and non-replicating plasma cells, reside in low numbers in the skin of channel catfish. following immunization against the protozoan parasite ichthyophthirius multifiliis, which infects skin and gills, the number of asc in skin increased 20-fold, indicating tha ...200818045689
complement expression in common carp (cyprinus carpio l.) during infection with ichthyophthirius multifiliis.a real-time pcr assay for determination of the complement response to infection with the ectoparasite ichthyophthirius multifiliis in carp is presented. specific primers were designed for selected genes representing the three pathways of the carp complement system. the investigated complement molecules were c1r/s, c3, c4, c5, factor i, factor b/c2-a (bf/c2-a), mannose-binding lectin (mbl) and mbl-associated serine protease (masp). the expression of the selected genes was analyzed on rna extracts ...200717107712
fish immunity and parasite infections: from innate immunity to immunoprophylactic prospects.the increasing economic importance of fish parasitoses for aquaculture and fisheries has enhanced the interest in the defence mechanisms against these infections. both innate and adaptive immune responses are mounted by fish to control parasite infections, and several mechanisms described for mammalian parasitoses have also been demonstrated in teleosts. innate immune initiation relies on the recognition of pathogen-associated molecular patterns (pamps) by pathogen recognizing receptors (prrs). ...200818783835
development of specific pcr assays for the detection of cryptocaryon irritans.cryptocaryon irritans is one of the most important protozoan pathogens of marine fish, causing the "white spot" disease and posing a significant problem to marine aquaculture. in the present study, a c. irritans-specific reverse primer (s15) was designed based on the published sequence of the second internal transcribed spacer (its-2) of ribosomal dna (rdna) of c. irritans and used together with the conserved forward primer p1 to develop a specific polymerase chain reaction (pcr) assay for direc ...200818463896
immune-relevant genes expressed in rainbow trout following immunisation with a live vaccine against ichthyophthirius multifiliis.rainbow trout oncorhynchus mykiss were immunised by intra-peritoneal injection using a live vaccine based on ichthyophthirius multifiliis (ich) theronts, which previously has shown protection against white spot disease. samples were taken pre-vaccination and on day 1, 7, 21 and 28 post-immunisation (p.i.). expression of immune relevant genes in the liver, spleen and head kidney was monitored by qpcr. to describe the immune reaction following this immunisation, a series of genes encoding cytokine ...200818814544
copper sulfate toxicity to two isolates of ichthyophthirius multifiliis relative to alkalinity.theronts from 2 different strains of ichthyophthirius multifiliis (ar1 and ar5) were exposed to copper sulfate (cuso4) in waters of different total alkalinities and observed for 4 h to determine relative toxicity and kinetics of parasite mortality. consistent with the known solubility properties of the metal, cu was significantly more toxic to cells maintained under low (48 mg l(-1)) compared with high (243 mg l(-1)) total alkaliniity conditions. this was reflected in both the median lethal conc ...200919301634
effect of immunization of channel catfish with inactivated trophonts on serum and cutaneous antibody titers and survival against ichthyophthirius multifiliis.two trials were conducted to determine the effect of immunization of channel catfish with inactivated trophonts on serum and cutaneous antibody titers and survival against ichthyophthirius multifiliis fouquet (ich). in trial i, catfish were immunized intraperitoneally (ip) with: 1) 1% formalin-inactivated trophonts, 2) 3% formalin-inactivated trophonts and 3) freeze-thawed trophonts. positive and negative control catfish were immunized with live theronts and 5% bovine serum albumin (bsa), respec ...200918973816
ichthyophthirius multifiliis infection induces apoptosis in different species of tilapia.the parasitic ciliate ichthyophthirius multifiliis (ich) is one of the most important protozoan pathogens of freshwater fish worldwide. examination of 4 species of tilapia from the river nile recorded highest rate infection in oreochromis niloticus, followed by oreochromis aureus, sarotherodon galilaeus and tilapia zilli. by electron microscopy, apoptotic cells collected from tilapia species infected with "ich" showed an aggregation on the apical and basal parts of the ciliated and non-ciliated ...200919795773
acute toxicity of peracetic acid (paa) formulations to ichthyophthirius multifiliis theronts.peracetic acid (paa) is an antimicrobial disinfectant used in agriculture, food processing, and medical facilities. it has recently been suggested as a means to control infestations of ichthyophthirius multifiliis. the purpose of this study was to determine the acute toxicity of two products containing 4.5% and 40% paa to i. multifiliis theronts from two geographically separate isolates. theronts were exposed to concentrations of paa in 96-well plates containing groundwater at 23 degrees c. acut ...200919221794
parasites of apollonia melanostoma (pallas 1814) and neogobius kessleri (guenther 1861) (osteichthyes, gobiidae) from the danube river in austria.two invasive fish species, the round goby apollonia melanostoma syn. neogobius melanostomus (pallas 1814) and the bighead goby neogobius kessleri (günther, 1861), have established a firm population in austrian waters during the past 15 years. as there have been no records of the parasite fauna from these populations, a total of 79 specimens of a. melanostoma and 12 specimens of n. kessleri were examined for parasites between may and october 2007 from three different sampling sites from the danub ...201019627624
[physiological response of experimental challenge of ichthyophthirius multifiliis (fouquet, 1876) in jundiá (rhamdia quelen quoy and gaimard, 1824) fingerlings rather fed with different lipid sources].a limiting factor in the early stage of the jundiá (rhamdia quelen quoy; gaimard, 1824) culture is the presence of diseases such as ichthyophthiriasis or "ich". dietary polyunsaturated fatty acids (pufas) have a potent immunomodulatory activity; and this activity depend of the fish species, quantity/quality of the dietary pufas. the aim of this study was evaluate the physiologic response of jundiá, rather fed diets with different sources of fatty acids when challenge to ich disease. fingerlings ...200818823575
enhanced mortality in nile tilapia oreochromis niloticus following coinfections with ichthyophthiriasis and streptococcosis.ichthyophthirius multifiliis fouquet (ich) and streptococcus iniae are 2 major pathogens of cultured nile tilapia oreochromis niloticus (l). currently there is no information available for the effect of coinfection by ich and s. iniae on fish. the objective of this study was to determine the effects of parasite load and ich development size on fish mortality following s. iniae infection. low mortality (< or =20%) was observed in tilapia exposed to ich or s. iniae alone. mortalities increased fro ...200919750806
outbreaks of ichthyophthirius multifiliis in redtail barbs barbus haasi in a mediterranean stream during 2008, inland waterways in catalonia (northeast iberian peninsula, spain) experienced one of the worst droughts recorded in this region in recent decades. during this period, an epizootic of ichthyophthirius multifiliis was detected for the first time in a mediterranean stream, with 21% prevalence in a population of redtail barbs barbus haasi. environmental features and the fish population in this stream were compared during 2007-2009. fish density and the average fish size were reduced signif ...200920043406
antimicrobial peptides derived from hemoglobin are expressed in epithelium of channel catfish (ictalurus punctatus, rafinesque).the beta-chain of the respiratory protein hemoglobin (hbbeta), has recently been identified in novel sites, including mammalian macrophages and alveolar epithelium, as well as in gill microsomes of fish. however, the functional significance of extra-erythrocytically expressed hemoglobin has been unclear. here we show inducible expression and upregulation of antimicrobial peptides (amps) homologous to hbbeta in the gill epithelium of channel catfish (ictalurus punctatus) in response to parasitic ...200818538841
evaluation of continuous 4-day exposure to peracetic acid as a treatment for ichthyophthirius multifiliis.the parasitic ciliate ichthyophthirius multifiliis infests all species of freshwater fish and can cause severe economic losses in fish breeding. the most effective treatment, malachite green, has been banned in europe and north america for use in food fish production. peracetic acid (paa) was found to be toxic to i. multifiliis theronts at low concentrations. i. multifiliis-infested carp were exposed to 1 mg/l paa in a dynamic exposure by means of peristaltic pumps. five days after infestation, ...201019902253
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