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temperature-dependent reproduction and survival of gyrodactylus salaris malmberg, 1957 (platyhelminthes: monogenea) on atlantic salmon (salmo salar l.).the relationship of survival and reproduction of gyrodactylus salaris malmberg on the atlantic salmon (salmo salar) to water temperature (2.5-19.0 degrees c), was studied on the basis of temporal sequence of births and age at death of individual parasites on isolated salmon, and of infrapopulation growth on isolated and grouped salmon. mean life-span of the parasite was negatively correlated with water temperature: 33.7 days at 2.5 degrees c and 4.5 days at 19.0 degrees c. the average number of ...19912038497
the chemotherapy of monogeneans which parasitize fish: a review.monogeneans which parasitize fish are still treated by bathing the fish in solutions of simple chemicals or staining dyes. in the early 1960s an insecticide, trichlorphon, replaced to a large extent the formerly used simple chemicals. its success was greater specificity against monogeneans and other ectoparasites, and to its great tolerance by the fish. the fact that the number of important monogenean species (i.e. pseudodactylogyrus anguillae, p. bini, gyrodactylus salaris) which cannot be trea ...19911937280
occurrence of infectious fish diseases in fish farms in northern finland.a total of 47 fish located in 10 lake and river systems in northern finland were examined for furunculosis, enteric redmouth diseases (erm), viral fish diseases and the parasite gyrodactylus salaris. furunculosis was found in 2 fish farms in different watercourses, erm in 8 fish farms in 3 watercourses and viral diseases were not found at all. g. salaris was looked for only in salmon and rainbow trout and was found in both species in 3 farms belonging to 2 watercourses.19921502999
population dynamics and interrelationships of some dactylogyrus and gyrodactylus species on cyprinus carpio.during 1986/87, 922 carps have been examined for ectoparasitic helminths. altogether 6 species of gyrodactylus and 4 species of dactylogyrus were found. the most frequent parasite on the gills was d. extensus; it shows a great tolerance to the water temperature with two peaks of infestation between 2 and 9 degrees c. additionally, relationships between the seasonal dynamics of the invasion cycle of d. extensus and d. anchoratus were recognized. in addition to dactylogyrus 2 species of gyrodactyl ...19902291498
gyrodactylus bohemicus sp. n. (monogenea: gyrodactylidae) from oncorhynchus mykiss (walbaum) and salvelinus fontinalis (mitchill) (clupeiformes: salmonidae) in czechoslovakia.gyrodactylus bohemicus sp. n (gyrodactylidae: monogenea) is described from the fins, skin and gill filaments of oncorhynchus mykiss (walbaum) and salvelinus fontinalis (mitchill) (clupeiformes: salmonidae) from a trout farm in czechoslovakia. g. bohemicus sp. n. is most closely related to g. thymalli zitnan, 1960 and g. magnus konovalov, 1967 in the shape of the anchors, the ventral and the dorsal bar, but can be distinguished from both these species by the shape of the marginal hook proper.19921291456
gyrodactylus costatae sp. n. (gyrodactylidae: monogenoidea) from lefua costata (kessler). 19761278824
variability of hard parts of opisthaptor of two species of gyrodactylus nordmann, 1832 (monogenoidea) from phoxinus phoxinus (l.).the morphological and metrical variability of hard parts of opisthaptor was studied in the representatives of local populations of gyrodactylus aphyae malmberg, 1957 and g. macronychus malmberg, 1957. the changes within the range of variability, which were observed during the year, correspond to regular and periodical changes in the environmental temperatures. the hard parts of opisthaptor were much smaller in specimens occurring during warm seasons than in specimens occurring during cold season ...19761278817
two new species of the genus gyrodactylus (monogenea) from the fins of leuciscus cephalus (l.).gyrodactylus kearni sp. n. and g. lamberti sp. n. (monogenea: gyrodactylidae) are described from the fins of the freshwater fish, leuciscus cephalus (l.) (cyprinidae), from the rokytná river and stĕpánovický brook (basin of the river danube), czechoslovakia, g. kearni sp. n. is most related to g. leucisci zitnan, 1964 in the shape and size of marginal hooks, but can be separated from it in the shape of anchors and ventral bar. g. lamberti sp. n. is most closely related to g. gobii shulman, 1953 ...19902093614
gyrodactylus konovalovi sp. n. (gyrodactylidae: monogenoidea) from phoxinus lagowskii dybowski.a new species of the genus gyrodactylus, g. konovalovi, from the fins, gills and skin of phoxinus lagowskii dybowski is described. the specimens were found for the first time in the mongolian people's republic by ergens and dulmaa (1967) and were erroneously determined as d. macronychus malmberg, 1957.1976950188
infections of gyrodactylus bullatarudis and gyrodactylus turnbulli on guppies (poecilia reticulata) in trinidad.gyrodactylus bullatarudis turnbull, 1956, and gyrodactylus turnbulli harris, 1986, are recorded from guppies (poecilia reticulata) from the northern mountains of trinidad. mixed infections of the 2 species were found at 9 localities. gyrodactylus turnbulli had a predominantly posterior distribution on the fishes, whereas g. bullatarudis was more anteriorly distributed. this is the first record of these species from guppies collected from within their original range.19921403438
gyrodactylus plotosi n. sp. (trematoda: monogenea) from the silurid fish plotosus lineatus from the philippines. 1977847866
health status of salmonids in river systems in natal. i. collection of fish and parasitological examination.a detailed microbiological and parasitological survey of salmonids and indigenous fish in the upper reaches of selected river systems in natal was undertaken. fish were collected from the rivers by electro-fishing, from dams by gill netting and from hatcheries along the rivers. a total of 678 fish from 26 different sites along 8 river systems were collected. no parasites could be detected on fish from four of the rivers tested. parasites were, however, detected on fish from large production site ...19911881656
redescription of two species of the genus gyrodactylus nordmann, 1832 (monogenoidea) from misgurnus anguillicaudatus.a redescription is given of gyrodactylus macracanthus hukuda, 1940 and g. micracanthus hukuda, 1940. g. paralatus gussev, 1955 was placed in synonymy with the species g. macracanthus. specimens determined by ergens and dulmaa (1968) to be g. paralatus are considered to be identical to g. micracanthus.19751222919
new species of gyrodactylus and dactylogyrus (trematoda: monogenea) from fishes of nebraska.six new monogenetic trematodes are described from nebraska fishes: gyrodactylus bulbacanthus sp. n. from fundulus kansae (garman); g. callawayensis sp. n. from notropis lutrensis (baird and girard); g. eos sp. n. from phoxinus eos (cope); g. nebraskensis from phoxinus neogaeus (cope); g. planensis from notropis dorsalis (agassiz); and dactylogyrus pectenatus from pimephales promelas (rafinesque). this is the second report of monogeneans from nebraska fishes.1977915609
two new species of gyrodactylus (monogenoidea) from mongolian brachymystax lenox (pallas). 1978640527
new approaches to the systematics of the ancyrocephalid monogenea from nearctic freshwater fishes.a total of 133 ancyrocephalid species found on nearctic freshwater fishes have been named. of these, 103 are now considered valid; 14 and 16 have been declared previously as synonyms or species inquirendae, respectively, and urocleidus rarus mizelle, 1940, is designated as a species inquirenda in the present work. a cladistic analysis, based on 13 binary and 4 multistate characters and 32 apomorphic character states was carried out. generalized forms of entobdella, gyrodactylus, and tetraonchus ...19902299514
gyrodactylus somnaensis sp. n. (monogenea: gyrodactylidae), a new fish parasite from the basin of the river amur. 19902093610
experimental verification of the water temperature effect on the micropopulation growth of gyrodactylus rutilensis gläser, 1974 (monogenea). 19902370025
new trends in parasitic infections of cultured freshwater fish.the 1980s are characterized by the appearance of new fish parasitoses, the clarification of the aetiology of diseases and new insights into the process of infection and the development of important parasites, especially myxosporidians. two phaerosporoses have entered into the foreground: swimbladder inflammation (sbi) caused by sphaerospora renicola in common carp and proliferative kidney disease (pkd) in salmonids. both diseases must be reported in the german democratic republic (gdr). the conn ...19892669320
on the dissemination of two far east monogenean parasites (dactylogyrus achmerovi gussev, 1955 and gyrodactylus kherulensis ergens, 1974, of carp (cyprinus carpio l.)) in czechoslovakia. 19911937271
experimental verification of the effect of constant and changing water temperature on the micropopulation growth in gyrodactylus gobiensis gläser, 1974 (monogenea) parasitizing gudgeon (gobio gobio l.).it has been verified under laboratory conditions that constant and changing water temperature markedly affects the micropopulation growth in gyrodactylus gobiensis parasite on the body surface of gudgeons (gobio gobio l.). at a water temperature of 12 degrees c, the number of gyrodactylids gradually increased up to the mean value of 63 specimens per host, which was reached on days 27-28 after experimental infection. at a constant temperature of 18 degrees c, the parasites completely disappeared ...19911937270
notes on gyrodactylus gussevi ling mo-en, 1962 (monogenea: gyrodactylidae).the authors describe a species which is strikingly similar to the species gyrodactylus gussevi ling mo-en, 1962 on the basis of morphometrical evaluation of 6 gyrodactylid specimens found on the fins of parasilurus asotus (l.) which was captured in the river amur near khabarovsk. due to inaccurate and incomplete original description of g. gussevi, the authors have to determine this species only provisionally as g. gussevi. as a result of evident appurtenance to g. latus--complex, p. asotus seems ...19911916537
two new species of gyrodactylus (monogenoidea) from schizothorax intermedius mcclelland from the river kafirnigan.two new species of gyrodactylus, namely g. kafirniganensis sp. n. and g. hemivicinus sp. n., are described from the fins and nostrils ofschizothorax intermedius from the river kafirnigan (tajik ssr).1976132394
three new species of gyrodactylus (monogenoidea) from varicorhinus capoeta gracilis (keyserling) from the river lenkoranka.three new species of gyrodactylus nordmann, 1832 are described from varicorhinus capoeta gracilis (keyserling) from the river lenkoranka (azebaijan ssr) as follows: g. varicorhini sp. n., g. capoetai sp.n. and g. mikailovi sp.n.1976132393
infrapopulation dispersal of gyrodactylus colemanensis (monogenea) on fry of salmo gairdneri.manipulative positioning of gyrodactylus colemanensis on individually isolated fry of salmo gairdneri was used to examine the behavior of the parasite during colonization and the influence that site of invasion has on size and spatial distribution of ensuing infrapopulations. the parasite's initial response was to relocate posteriorly on the host's body; those that reached a fin usually end up on or adjacent to the fin's margin. individuals monitored for up to 15 days postinfection moved both an ...19892795374
a rapid stain technique for the haptoral bars of gyrodactylus species (monogenea). 197876672
a new species of the genus gyrodactylus nordmann, 1832 (monogenea) from gobio gobio (l.).gyrodactylus dykovae sp. n. (monogenea: gyrodactylidae) is described from the fins of the freshwater fish, gobio gobio (l.) (cyprinidae), from the rokytná river near moravský krumlov, czechoslovakia. this species is most related to g. gobii shulman, 1953 from which it differs by possessing more robust anchors with considerably larger shaft and by the morphology of the hook proper of marginal hooks.19911916536
nuclear bodies in the egg cells of a gyrodactylus species (platyhelminthes, monogenea).the presence and ultrastructure of distinctive nuclear bodies in a mature 'egg cell' of a gyrodactylus sp. are described. these electron-dense granular bodies, which appear in section as open or closed rings or as a solid mass are not membrane-bound and lie in clusters close to the nucleolus. the nuclear bodies are compared with the nuclear-inclusion bodies previously reported in platyhelminths. the possible origin, significance and role of the nuclear bodies in this gyrodactylus sp. are discuss ...19921332024
variability of the hard parts of opisthaptor of gyrodactylus leucisci zitnan, 1964 (monogenea: gyrodactylidae). 19911916527
treatment of fish parasites. 4. effects of sym. triazinone (toltrazuril) on monogenea.for chemotherapy in fish parasitized by monogeneans, toltrazuril was tested in vivo and in vitro against gill-parasitizing species (dactylogyrus vastator, d. extensus, d. cornu, pseudodactylogyrus anguillae, diplozoon paradoxum, dip. homoion) as well as the skin-parasitizing species gyrodactylus arcuatus. naturally infected fish were incubated at 20 degrees c for 0.3, 1, 2, 3, 4, and 6h in water containing 0.5, 10, 20, 30, and 50 microgram toltrazuril/ml. in general, the damage observed resulted ...19883237675
parasitological study of a population of tiber river eels (anguilla anguilla).a study was conducted on the parasitofauna of anguilla anguilla caught in the section of the tiber river south of rome (italy). the sample examined consisted of 417 specimens that were classified by stage (elver, young yellow eel, yellow eel and silver eel) and season of sampling. the following species were identified: trypanosoma granulosum, eimeria anguillae, myxidium giardi, sphaerospora reichenowi, myxobolus sp., trichodina anguilli, ichthyohodo sp., gyrodactylus anguillae, bothriocephalus c ...19873508508
temporal changes in aggregation: a laboratory study.changes in the variance to mean ratio and the parameter k of the negative binomial distribution were used to study temporal changes in the degree of aggregation of the monogenean parasite, gyrodactylus turnbulli in free-running laboratory populations of the guppy, poecilia reticulata. the parasite undergoes recurrent epidemic cycles in the host population under conditions of regular immigration of uninfected guppies. during the early phase of the epidemic, heterogeneity among fish together with ...19873614993
diversity of the parasite assemblage of fundulus zebrinus in the platte river of nebraska.changes in the values of the shannon h' diversity index as determined for individual hosts (infraassemblage diversity), host samples (sample assemblage diversity), and for species density are reported for an assemblage of 7 parasites in fundulus zebrinus in the platte river in nebraska for a 5-yr period. the parasites were: myxosoma funduli (gill), trichodina sp. (gill), gyrodactylus bulbacanthus (gill), salsuginus sp. (gill), gyrodactylus stableri (body surface), and neascus sp. (= posthodiplos ...19883357111
goussia girellae n. sp. (apicomplexa: eimeriorina) in the opaleye, girella nigricans.goussia girellae n. sp. is described from the opaleye fish, girella nigricans. merogonic stages were observed in the apices of intestinal epithelial cells, in the lamina propria, and in extra-intestinal sites including liver, gills, and spleen. gamonts were observed in the intestinal epithelial cells. only unsporulated oocysts were detected in the intestine, and sporulation occurred when feces containing oocysts were incubated for 48 h in seawater at 21 degrees c. oocysts are elongated (24.8 x 1 ...19883397916
contribution to the knowledge of gyrodactylus gurleyi price, 1937 (monogenea: gyrodactylidae).gyrodactylus longoacuminatus zitnan, 1964, forma minor sensu ergens (1985) was identified as g. gurleyi price, 1937. morphological and metrical evaluations of the hard parts of opisthaptor of more than 200 specimens provided data on the variability of this parasite; cyprinus carpio haematopterus represents its new host. since the shape of the hard parts of opisthaptor of g. gurleyi is very similar to that of g. longoacuminatus, further detailed studies of the two species will be necessary, parti ...19873666611
experimental verification of the effect of physical condition of gobio gobio (l.) on the growth rate of micropopulations of gyrodactylus gobiensis gläser, 1974 (monogenea).it has been verified experimentally that the growth rate of g. gobiensis micropopulations is markedly affected by the physical condition of the host (gobio gobio). if the fish were weakened by 50% oxygen deficiency and lack of food, the number of parasites increased much more rapidly than on the fish also unfed but kept in water with 100% oxygen content. if the fish weakened by oxygen deficiency were intensively fed, the growth of the parasite micropopulations started to slow down after 4-5 days ...19873666612
experimental verification of the effect of the form (scaly or scaleless) of carp host (c. carpio l.) on the growth rate of micropopulations of gyrodactylus katharineri malmberg, 1964 (monogenea).it was demonstrated that the growth rate of gyrodactylus katharineri micropopulations parasitizing the fry of cyprinus carpio l. was effected by water temperature and by the form of the fish host (scaly or scaleless). at lower water temperature (12 degrees c) the number of parasites increased in both host forms approximately at the same intensity. in warmer water (18 degrees c), the parasites reproduced intensively only on the scaly form of fish, whereas no parasites were found on the scaleless ...19873428761
four new species of gyrodactylus from fishes of alabama.four new species of gyrodactylus are described from fishes of alabama. gyrodactylus dorosomae was collected from dorosoma cepedianum (le sueur) and d. petenense (gunther); g. parvicirrus from notropis atherinoides raf; g. lythruri from notropis b. bellus hay and n. atrapiculus snelson; and g. nigrum from etheostoma nigrum raf.19751117368
treatment of fish parasites. 2. effects of praziquantel, niclosamide, levamisole-hcl, and metrifonate on monogenea (gyrodactylus aculeati, diplozoon paradoxum).in research for successful treatment of fish parasitized by monogeneans, four substances (praziquantel, niclosamide, levamisole-hcl, and metrifonate) were tested in vivo against gyrodactylus aculeati parasitizing the skin of sticklebacks (gasterosteus aculeatus). fish were incubated in water containing different solutions of the drugs. praziquantel, niclosamide and levamisole-hcl were effective against gyrodactylus aculeati. praziquantel caused irreversible lesions in the parasite tegument (begi ...19873615395
gyrodactylus salmonis (yin and sproston, 1948) parasitizing fry of salvelinus fontinalis (mitchill).fry of brook trout, salvelinus fontinalis (mitchill), were infected under controlled conditions with gyrodactylus salmonis (yin and sproston, 1948) and the course of infection followed for 22 days in four groups of 40 fish and for 60 days in a group of 200 fish. between 15 and 44% mortality occurred among infected groups compared with less than 5% in noninfected control groups. intensely infected moribund fish were cachexic, lethargic, and often darkened in color. histologic studies revealed tha ...19863712646
a simple model of a gyrodactylus population. 19744411750
gyrodactylus kherulensis sp. n. (monogenoidea) from the carp. 19744448438
gyrodactylus alexanderi: reproduction, mortality, and effect on its host gasterosteus aculeatus. 19744451900
nomenclatoric problems of gyrodactylus gussevi najdenova, 1966 and g. proterorhini ergens, 1967 (monogenoidea: gyrodactylidae). 19724670840
a redescription of three species of the genus gyrodactylus nordmann, 1832 (monogenoidea) from endemic fishes of the baikal lake. 19724670824
gyrodactylus karatagensis sp. n. (monogenoidea) from the fins of noemacheilus stoliczkai. 19724670825
some remarks on the taxonomic position of gyrodactylus luehei (lühe, 1909) sensu roman-chiriac, 1960 (gyrodactylidae: monogenoidea). 19724670826
seasonal abundance of gyrodactylus macrochiri hoffman and putz, 1964 on bluegill and largemouth bass. 19734701186
[2 new species of the genus gyrodactylus nordmann (monogenoidea) from perccottus glehni]. 19734703378
monogenetic trematodes from the bay of quinte area, ontario. ii. genus gyrodactylus nordmann, 1832. 19715165922
notes on gyrodactylus cobitis bychowsky, 1933 (gyrodactylidae: monogenoidea). 19734770807
[gyrodactylus medius kathariner, 1894 (monogenoidea: gyrodactylidae), its variability, occurrence and distribution]. 19744829583
studies on gyrodactylus (trematoda: monogenea) with descriptions of five new species from the southeastern u. s. 19655848832
attachment of gyrodactylus to gasterosteus and host response. 19725057221
studies on monogenetic trematodes. xli. gyrodactylus ensatus sp. n., the first species of the genus described from amphibia. 19685647109
temperature effect on the distribution of gyrodactylus elegans on goldfish. 19695816099
development of infections of gyrodactylus colemanensis mizelle and kritsky, 1967 (monogenea) and the effect on fry of salmo gairdneri richardson.the development of infections of gyrodactylus colemanensis mizelle and kritsky, 1967 (monogenea) and their effect on fry of salmo gairdneri richardson are examined experimentally. starting with initial infections of 1 to 10 worms per fry, intensity in 2 replicate groups increased to peaks of 55 and 65 on day 22 post-infection and declined to 0 by days 67 and 85 post-infection. the parasites were numerically aggregated within the host groups and there was a negative correlation between intensity ...19863806317
five new species of gyrodactylus (trematoda: monogenea) from the southeastern u. s. 19676066756
[gyrodactylus rasini n. sp. (monogenoidea: gyrodactylidae), a parasite of the gills of xiphophorus helleri bred as aquarium fish in cssr (czechoslovakia)]. 19734205676
[morphogenesis of the chitinous parts of the haptor in gyrodactylus tincae (malmberg, 1956) malmberg 1964 (monogenoidea) and their morphological-metric variability]. 19655875144
detection of sperm within gyrodactylus (platyhelminthes, monogenea) tissues using fluorescence and transmission electron microscopy.a rapid fluorescent staining method demonstrating spermatozoa within gyrodactylid monogeneans is described. gyrodactylids fixed and stained in 2% acetic acid containing 1 microgram ml-1 bisbenzimide (hoechst 33258) were viewed using epifluorescence microscopy. in addition to staining sperm in the testis, seminal vesicle and seminal receptacle, the technique highlighted sperm in the gut and cytoplasmic lining of the uterus, locations from which they had not previously been recorded. the technique ...19979211503
[helminths in trout (fam. salmonidae) in freshwater reservoirs].a survey is made of the helminths parasitizing in representatives of family salmonidae caught mainly in the free fresh-water basins in the country. more detailed information and study concerned the american and the balkan trout--salmo irideus gairdneri and salmo trutta m. fario respectively--because of their higher economic importance. in the course of the study some corrections were made of the names of some of the species in the light of the new data obtained concerning all helminths alreay me ...19827179733
control of parasitic infestations in killifish (fundulus parvipinnis).california killifish (fundulus parvipinnis) trapped in a southern california estuary were infested with gyrodactylus sp, argulus sp, or ergasilus sieboldii. they were treated with 0,0-dimethyl 2,2,2-trichloro-1-hydroxyethylphosphonate (dthp). the effective dosage regimen for gyrodactylus was 7.50 mg/l for 1 hour on day 1, 3.25 mg/l for 1 hour on day 5, and 0.75 mg/l for 1 hour on day 9; for argulus, 2.50 mg/l for 1 hour once only; for ergasilus, 2.50 mg/l for 1 hour once every third day for thre ...19817242019
the effect of gyrodactylus salaris (monogenea) on the epidermis of atlantic salmon, salmo salar, parr in the river batnfjordselva, norway.skin morphology of atlantic salmon, salmo salar, parr infected with gyrodactylus salaris was examined for 3 yr in the river batnfjordselva in norway and compared to that of uninfected salmon parr from a neighboring river. the epidermis of the infected population had more cell layers and was thicker than the epidermis of parr from the uninfected population. the number of mucous cells did not differ, and no seasonal changes in morphology of the epidermis were detected in either rivers. intensity o ...19979406797
apparent drug resistance to the organophosphate dimethyl (2,2,2-trichloro-1-hydroxyethyl) phosphonate by monogenetic trematodes.gyrodactylus elegans on goldfish, (carassius auratus) from a commercial farm were resistant to recommended dosages of dimethyl (2,2,2-trichloro-1-hydroxyethyl) phosphonate. controlled experiments suggest that a dosage 100 times the commonly recommended minimal dosage (.25 mg/l) was required to remove trematodes. a hypothesis is proposed to account for the development of drug resistant trematodes based on the life cycle of the parasites and continual drug exposure.19807411739
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
trichrome staining of gyrodactylus sclerites and soft tissues following fixation in ammonium picrate-glycerin, including an improved rendition of the haptoral bars of g. turnbulli.a simple technique using modified mallory stain in the transferral of gyrodactylus specimens from ammonium picrate-glycerin to a permanent mountant is described. hamuli, their connecting bars and the penis sclerites are well defined by the technique as are muscles and tendons, cell nuclei, tegument and gland cells. as well as being useful in the study of general anatomy, the technique enhances the observation of the taxonomically important ventral and dorsal bars. in order to show this, improved ...19957543508
six new species of gyrodactylus (monogenea) from the southeastern u. s. 19676035715
phylogenetic analysis of gyrodactylus salaris malmberg, 1957 based on the small subunit (18s) ribosomal rna gene. 19957630378
on the occurrence and morphology of gyrodactylus pterygialis from saithe pollachius virens in a norwegian fjord.a total of 308 pollachius virens from a fjord near bergen, western norway, were examined for gyrodactylus pterygialis over a 14-mo period; g. pterygialis showed the highest prevalence and density in winter/spring (november, january, march, and april pooled) but was absent in some months (august, september, and november). the morphology of the opisthaptoral hard parts of g. pterygialis were studied throughout the survey, and their variation is discussed with respect to host species, host locality ...19947799167
the population dynamics of gyrodactylus bullatarudis (monogenea) within laboratory populations of the fish host poecilia reticulata.experiments were undertaken to investigate the factors which influence the transmission dynamics of gyrodactylus bullatarudis within populations of laboratory guppies. the parasites possess a number of biological attributes which are almost unique amongst helminth parasites of vertebrates. these include the ability to reproduce viviparously and directly on the surface of the host, the ability to survive death of the host (for a short period of time) and the ability to transfer between hosts (des ...19846472882
the population age structure and reproductive biology of gyrodactylus salaris malmberg (monogenea).gyrodactylus salaris has recently become a major pathogen of atlantic salmon (salmo salar) in norway. the survivorship, population age structure and pattern of insemination of g. salaris were studied to determine the extent to which this species reproduces sexually. the age-specific mortality schedule of g. salaris could be described by an exponential model but day to day variations were large, with an increase in mortality after each birth. modelling population growth using the best fit mortali ...19948159462
treatment of fish parasites. 10. effects of a new triazine derivative, hoe 092 v, on monogenea: a light and transmission electron microscopy study.for chemotherapy of fish parasitized by monogeneans, a novel triazine derivative, 2-[3,5-alpha-dichloro-4-(4-methyl-sulfonylphenoxy)-phenyl]-1-methy l- hexahydro-1,2,4-triazine-3,5-dion (hoe 092 v), was tested in vivo against the gill- and skin-parasitizing species dactylogyrus extensus, d. vastator, and gyrodactylus arcuatus. naturally infected fish were incubated in aerated, separate tanks at 22 degrees c for 1, 2, 3, and 4 h in water containing 0, 1, 5, 10, or 15 micrograms hoe 092 v/ml, wher ...19938278338
host response to initial and challenge infections, following treatment, of gyrodactylus bullatarudis and g. turnbulli (monogenea) on the guppy (poecilia reticulata).the host response of poecilia reticulata peters against two species of gyrodactylus (g. bullatarudis turnbull, 1956 and g. turnbulli harris, 1986) was investigated by comparing the dynamics of infrapopulations arising from initial infections, challenge infections begun 1 day after formalin treatment of 3-day-old initial infections and challenge control infections. the primary host response of p. reticulata to gyrodactylus was shown to be non-(gyrodactylus)-species-specific. observations of diffe ...19968801557
freeze fixation-dehydration as a method of preparation of gyrodactylus (monogenea) for sem.freeze fixation-dehydration was used for the first time in the preparation of attached gyrodactylus for sem viewing. the technique provided instant immobilization of specimens before death and negligible shrinkage throughout the fixation-dehydration process. comparisons of sample means of two linear measurements of attached opisthaptors showed 20% more shrinkage of gyrodactylus fixed using 10% neutral buffered formalin than those which were freeze fixed. freeze fixation-dehydration was excellent ...19968991916
population dynamics of gyrodactylus salaris (monogenea) infecting atlantic salmon, salmo salar, parr in the river batnfjordselva, norway.population dynamics of gyrodactylus salaris on 5 year classes of atlantic salmon, salmo salar, in the river batnfjordselva in norway was studied from april 1991 to june 1994. prevalence was 100% on all year classes throughout the study period, except for a marked decline in winter and spring of 1992. median abundance generally increased during summer and peaked in september/october at levels between 400 and 1,300 parasites. the lowest number of parasites was observed during winter and spring. th ...19979057692
[contributions to microscopic anatomy and reproduction biology of gyrodactylus wagneri v. nordmann, 1832]. 19664167681
discrimination between gyrodactylus salaris, g. derjavini and g. truttae (platyhelminthes: monogenea) using restriction fragment length polymorphisms and an oligonucleotide probe within the small subunit ribosomal rna gene.the small subunit ribosomal rna (srrna) gene was amplified from gyrodactylus salaris using the polymerase chain reaction (pcr), cloned, and the complete gene sequence of 1966 bp determined. the v4 region of the srrna gene was identified and amplified from single specimens of g. salaris, g. derjavini and g. truttae. comparison of the v4 sequences from these three species revealed sequence differences from which restriction fragment length polymorphisms (rflps) were predicted and an oligonucleotid ...19957609994
two new sensory receptors in gyrodactylus sp. (platyhelminthes, monogenea, monopisthocotylea).two pairs of sub-surface ciliary aggregations, not previously described in gyrodactylid monogeneans, have been found in the antero-dorsal region of adult gyrodactylus sp. one pair lies more anteriorly and has several basal bodies without rootlets as well as modified cilia with single microtubules projecting into an extra-cellular cavity. a neuronal process extends posteriad. an anterior pocket connecting to this cavity is surrounded by cytoplasm that adjoins the ciliated cell by a septate juncti ...19947971933
histochemical characteristics of gyrodactylus derjavini parasitizing the fins of rainbow trout (oncorhynchus mykiss).histochemical studies of enzyme activities and structural elements in gyrodactylus derjavini mikailov, 1975 parasitizing fins of oncorhynchus mykiss walbaum were conducted. marked activities of non-specific esterase, acid phosphatase, alkaline phosphatase and amino-peptidase were found in the intestinal caeca of the parasite. a strong activity of acetylcholinesterase was seen in the nervous system. extraintestinal non-specific and eserine-sulphate resistant esterase was localized in the distal p ...19989868792
helminth ectoparasites of sillaginid fishes (perciformes: percoidei) have low species richness.just nineteen species of ectoparasitic helminths were found in a survey of over 1,500 individuals of 26 species of sillaginid fishes in the indo-west pacific. a twentieth worm is known only from the literature; a twenty-first, also known only from the literature, is considered a doubtful record. fifteen of the twenty worms are branchial monogeneans, one is a monogenean of the pharyngeal plates, one is an ectoparasitic digenean living under the scales, and three are leeches of the mouth cavity an ...19979332977
studies on monogenetic trematodes. xxx. five new species of gyrodactylus from the pacific tomcod, microgadus proximus (girard). 19676067099
studies on monogenetic trematodes. xxxi. five new species of gyrodactylus from california fishes. 19676067100
seasonal occurrence of gyrodactylus derjavini (monogenea) on brown trout, salmo trutta, and atlantic salmon, s. salar, in the sandvikselva river, norway.seasonal variation in prevalence and intensity of the ectoparasite gyrodactylus derjavini on brown trout parr, salmo trutta, and atlantic salmon parr, s. salar, and occurrence of g. derjavini on ascending sea trout, s. trutta m. trutta, in the sandvikselva river, southeastern norway, was recorded. in general, both prevalence and intensity increased and decreased correspondingly with the rise and fall in water temperature. however, both prevalence and intensity decreased in warm periods when repr ...19979406773
microenvironment of gyrodactylus derjavini on rainbow trout oncorhynchus mykiss: association between mucous cell density in skin and site selection.microhabitat selection of gyrodactylus derjavini on the body surface of rainbow trout changed markedly during a 6-week experimental infection period. pectoral fins, pelvic fins and anal fins were the most important sites (expressed in terms of parasite density) during the initial part of the infection. in the later stages of infection, the corneal surface and tail fin became increasingly more heavily infested. factors responsible for this dynamic site selection were investigated. the density of ...19989491421
gill parasites of mummichogs, fundulus heteroclitus (teleostei: cyprinodontidae): effects of season, locality, and host sex and size.i investigated the prevalences and densities of gill parasites in 4 seasonal samples of mummichog, fundulus heteroclitus (n=242), from 2 creeks differing in salinity in central chesapeake bay. the parasites (and overall prevalence ranges) were: mobile (12-88%) and sessile (0-50%) peritrichs (ciliophora); myxobolus funduli (58-94%) (myxozoa); gyrodactylidae (0-94%) (includes gyrodactylus sp. and fundulotrema sp.) and salsuginus sp. (74-100%) (monogenea); metacercariae of phagicola diminuta (75-10 ...19989576493
temperature dependent population growth of gyrodactylus derjavini on rainbow trout, oncorhynchus mykiss.rainbow trout were experimentally infected with the ectoparasitic monogenean gyrodactylus derjavini at three temperatures, 5.5 degrees c, 11.6 degrees c and 18.7 degrees c. subsequently, the infection level was monitored during the following 6 weeks. the population growth was positively correlated with temperature in the initial part of the investigation. at 18.7 degrees c growth of the parasite population was fast reaching a peak abundance within 3 weeks, whereafter the infection level decrease ...19989639894
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
[new species of the genus gyrodactylus nordmann, 1832 (monogenea) from schizopygopsis stoliczkai]. 19806446074
binding and lethal effect of complement from oncorhynchus mykiss on gyrodactylus derjavini (platyhelminthes: monogenea).a lethal effect of rainbow trout oncorhynchus mykiss plasma containing intact complement factors on gyrodactylus derjavini was demonstrated. it was associated with binding of complement factor c3 to certain carbohydrate-rich parasite structures. parasites were exposed in vitro to plasma from rainbow trout. untreated plasma from infected and uninfected fish showed lethal effects on the parasites within 1 h, whereas prior heat inactivation of complement prevented any parasite killing. inhibition o ...19989676245
oral pharmacological treatments for parasitic diseases of rainbow trout oncorhynchus mykiss. ii. gyrodactylus sp.a total of 24 drugs were evaluated as regards their efficacy for oral treatment of gyrodactylosis in rainbow trout oncorhynchus mykiss. in preliminary trials, all drugs were supplied to infected fish at 40 g per kg of feed for 10 d. twenty-two of the drugs tested (aminosidine, amprolium, benznidazole, bithionol, chloroquine, diethylcarbamazine, flubendazole, levamisole, mebendazole, metronidazole, niclosamide, nitroxynil, oxibendazole, parbendazole, piperazine, praziquantel, ronidazole, secnidaz ...19989745715
life history specializations of monogenean flatworms: a review of experimental and microscopical studies.this review illustrates the use of experimental approaches combined with microscopy to study the biology of monogenean parasites. studies of feeding, development, reproduction, and systematics have been based on gyrodactylids, flatworms infecting teleost fishes. in a contrasting system involving an amphibian host in a desert environment, analysis of adaptations to extreme conditions has focused on pseudodiplorchis americanus. the unusual reproductive strategies, particularly the interactions bet ...19989764919
longer-term population dynamics of gyrodactylus bullatarudis and g. turnbulli (monogenea) on adult guppies (poecilia reticulata) in 50-i experimental arenas.two suprapopulations of monogeneans, one each of gyrodactylus bullatarudis and g. turnbulli, on two groups of ten experimentally infected adult guppies (poecilia reticulata) were maintained separately in 50.1 aquaria and monitored over 210 days. the g. bullatarudis population had a pattern of initial growth, then a subsequent decline to extinction after 40 days. g. turnbulli, after initial population growth and decline, maintained low-intensity infections (0.33-3.3 parasites/host) on six hosts o ...19989766905
killing of gyrodactylus salaris (platyhelminthes, monogenea) mediated by host complement.gyrodactylus salaris, an important pathogen of atlantic salmon salmo salar, has been shown to be highly sensitive to factors in host serum and mucus, being killed rapidly (50% within 1 h) by serum at a dilution of 1:200. the time needed for killing was inversely proportional to serum concentration. similar effects were noted using host mucus, which contained approximately 1/20th of the anti-gyrodactylus activity of serum. serum activity was abolished completely by heating at 45 degrees c for 30 ...19989778636
biodiversity of parasites in a freshwater environment with respect to pollution: metazoan parasites of chub (leuciscus cephalus l.) as a model for statistical evaluation.this paper represents an attempt to evaluate the environmental indicative potential of the biodiversity of monogenean parasites using hierarchically structured species-abundance data. a logical set of statistical methods integrating standard diversity indices, a novel approach to quantitative analysis of cumulative species-abundance curves and species-abundance models was applied for this purpose. applicability of biodiversity measures was demonstrated using experimental data from a 1-year study ...19989801915
the use of statistical classifiers for the discrimination of species of the genus gyrodactylus (monogenea) parasitizing salmonids.this study applies flexible statistical methods to morphometric measurements obtained via light and scanning electron microscopy (sem) to discriminate closely related species of gyrodactylus parasitic on salmonids. for the first analysis, morphometric measurements taken from the opisthaptoral hooks and bars of 5 species of gyrodactylid were derived from images obtained by sem and used to assess the prediction performance of 4 statistical methods (nearest neighbours; feed-forward neural network; ...200010759084
ecological and genetic evidence for clonal reproduction in gyrodactylus gasterostei glaser, 1974.reproduction of isolated gyrodactylus gasterostei from the three-spined stickleback, gasterosteus aculeatus, has been investigated. three lineages of isolated parasites, without opportunity for cross- or self-fertilisation, continued to reproduce for up to 19 generations (224 births) until experiments were discontinued. most parasites gave birth to two daughters only, although four individuals in one lineage gave birth three times. after the final birth the empty uterus expanded, while a large o ...19989801918
gyrodactylus strelkovi sp.n. (monogenea: gyrodactylidae). a new fish parasite from the basin of the river amur. 19836662407
on the evolution within the family gyrodactylidae (monogenea).on the basis of six main types of protonephridial systems in the genus gyrodactylus and results from further studies of the protonephridial systems in other gyrodactylid genera and other monogenean families, evolutionary lines within the gyrodactylidae and the origin of the genera ooegyrodactylus, swingleus, gyrdicotylus and polyclithrum are discussed. an excretory bladder (on both sides of the body) with separate openings for the main canals of the anterior and the posterior systems, a median j ...19989801920
biodiversity of parasites in freshwater environment in relation to pollution.during 1994, 129 specimens of chub (leuciscus cephalus l.) from two localities, polluted--bolelouc, 80th river kilometer, near the city of olomouc, and unpolluted--brodské, 225th river kilometer, near the lanzhot on the morava river, were examined for metazoan parasites. altogether 38 metazoan parasite species including helminths, leeches and glochidia belonging to 14 genera were found, 34 in the case of unpolluted locality (brodské) and 28 in the polluted one (bolelouc). in both localities, 24 ...19979802067
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