| seasonality of two gill monogeneans from two freshwater fish from an oligotrophic lake in northeast finland. | the seasonal occurrence of dactylogyrus amphibothrium and discocotyle sagittata from the gills of ruffe (gymnocephalus cernuus) and whitefish (coregonus acronius), respectively was studied in lake yli-kitka, a large oligotrophic lake in northeast finland. the lake, located near the arctic circle, is ice-covered for 7-8 months of the year. the prevalence of d. amphibothrium infection was 70.7% and remained high throughout all size-classes of fish. the length distribution and developmental stages ... | 1990 | 2312218 |
| the population dynamics of the monogenean gill parasite discocotyle sagittata leuckart on windermere trout, salmo trutta, l. | | 1965 | 5887653 |
| cholinergic, serotoninergic and peptidergic components of the nervous system of discocotyle sagittata (monogenea:polyopisthocotylea). | cholinergic, serotoninergic (5-ht) and peptidergic neuronal pathways have been demonstrated in both central and peripheral nervous systems of adult discocotyle sagittata, using enzyme histochemistry and indirect immunocytochemistry in conjunction with confocal scanning laser microscopy. antisera to 2 native flatworm neuropeptides, neuropeptide f and the fmrfamide-related peptide (farp), gnffrfamide, were employed to detect peptide immunoreactivity. the cns is composed of paired cerebral ganglia ... | 1996 | 9024885 |
| larval survival characteristics and behaviour of the gill monogenean discocotyle sagittata. | the survival characteristics of discocotyle sagittata larvae are both age- and temperature-dependent. in laboratory studies at constant temperatures of 6, 10, 13, 18 and 22 degrees c, oncomiracidia had a maximum life-span of 96 h at 6 degrees c, declining with increasing temperature to 26 h at 22 degrees c. larval swimming activity was also age dependent, and continued for a large proportion of survival time. the relationship between time at which larvae stop swimming as a proportion of total su ... | 1998 | 9836314 |
| environmental effects on transmission of discocotyle sagittata (monogenea): egg production and development. | egg production by the freshwater gill monogenean discocotyle sagittata infecting rainbow trout (oncorhynchus mykiss) was monitored at 5, 13 and 18 degrees c; eggs were incubated at 6, 10, 13, 15, 16, 18, 22 and 26 degrees c and the hatching times determined. mean per capita output at 13 degrees c ranged from 0.8 eggs/worm/day (e/w/d) to 18.3 e/w/d for 25 hosts (burdens 1-17 worms/host). average egg production rates for worms in single burdens varied from 3 e/d to 14.6 e/d at 13 degrees c, mean 7 ... | 1998 | 9836315 |
| ultrastructure of spermiogenesis and spermatozoa of discocotyle sagittata (monogenea: polyopisthocotylea: discocotylinea). | ultrastructural analysis revealed that the spermatozoon of discocotyle sagittata (leuckart, 1842) is composed of two parallel axonemes, mitochondrion, nucleus and cortical microtubules. the nucleus, which occupies a central/distal position and has an unusual crescent-shaped profile, is slightly shorter than the mitochondrial rod. the two axonemes, which are of unequal length, and the cortical microtubules (up to 68 forming a continuous ring in the principal region) extend almost the entire lengt ... | 2001 | 11699656 |
| trickle and single infection with discocotyle sagittata (monogenea: polyopisthocotylea): effect of exposure mode on parasite abundance and development. | experimental infection of rainbow trout oncorhynchus mykiss (walbaum) with the monogenean discocotyle sagittata (leuckart, 1842) allowed comparison between trickle and single exposure, two infection modes demonstrated to occur in the wild. both types of infection resulted in mean larval attachment success around 50%, which was significantly dependent on dose of infective larvae used (p < 0.0001), but was not affected by mode of infection (p = 0.244). worms recovered from fish exposed to the same ... | 2002 | 12641200 |
| immunization of rainbow trout oncorhynchus mykiss against discocotyle sagiffata (monogenea). | rainbow trout oncorhynchus mykiss were injected intraperitoneally with 2 different discocotyle sagittata extracts dissolved in pbs and subsequently exposed to controlled infection. immunization resulted in significantly reduced (p < 0.0001) worm intensities in > 50% of vaccinated fish (response arbitrarily defined as parasite burdens < mean control intensity - 1 sd), irrespective of the immunization regime (different parasite extracts, dosing and application schedules) employed. the protective e ... | 2003 | 12887251 |
| the attachment of the monogenean discocotyle sagittata leuckart to the gills of salmo trutta l. | | 1960 | 14417697 |
| antibodies against discocotyle sagittata (monogenea) in farmed trout. | the relationship between discocotyle sagittata intensities and host length, weight and specific anti-parasite antibody titres was studied in 3 year-classes of farmed rainbow trout oncorhynchus mykiss and brown trout salmo trutta at the end of the annual transmission cycle. antibody titres were significantly higher in infected farmed fish than in naive controls, indicating that infection elicits immunoglobulin production. no correlation was found between host size and parasite burdens, nor betwee ... | 2003 | 14598994 |
| immunity in rainbow trout, oncorhynchus mykiss, against the monogenean discocotyle sagittata following primary infection. | rainbow trout (oncorhynchus mykiss) were experimentally infected by continuous or single exposure with the monogenean discocotyle sagittata. to determine whether immunity follows primary infection, fish were exposed to a secondary challenge by one of two modes: (1) primary infections were cleared with praziquantel (pzq) and hosts re-infected with 100 oncomiracidia; (2) parasites were allowed to reach maturity and hosts super-infected with 100 oncomiracidia. fish challenged after initial continuo ... | 2004 | 14740206 |
| evidence of complement-mediated killing of discocotyle sagittata (platyhelminthes, monogenea) oncomiracidia. | discocotyle sagittata oncomiracidia were rapidly killed when incubated in naïve plasma and immune sera from both rainbow trout (oncorhynchus mykiss) and brown trout (salmo trutta), the killing proceeding at a faster rate with blood material from the latter fish species. the lethal activity of naïve plasma and immune sera was comparable. this was abolished after incubation at 45 degrees c for 30 min and by the addition of edta but not egta supplemented with mg(2+), indicating that complement acti ... | 2004 | 15212729 |
| comparative susceptibility of brown trout and rainbow trout to discocotyle sagittata (monogenea). | the susceptibility of brown trout (salmo trutta) and rainbow trout (oncorhynchus mykiss) to the monogenean discocotyle sagittata in the united kingdom was assessed by experimental infection of naive fish. one month postinfection with 100 oncomiracidia/host, brown trout harbored significantly lower burdens (27.7 worms/host +/- 4.13 se) than rainbow trout (47.8 worms/host +/- 3.90; p = 0.002). this indicates that the consistently lower prevalence and intensity of d. sagittata recorded in naturally ... | 2004 | 15357099 |
| microhabitat selection of discocotyle sagittata (monogenea: polyopisthocotylea) in farmed rainbow trout. | microhabitat preference of the monogenean discocotyle sagittata (leuckart, 1842) was determined in late spring and late autumn in rainbow trout, oncorhynchus mykiss (walbaum), reared in the isle of man, u.k. discocotyle sagittata exhibits a preference for attachment to anterior gill arches: 29% of all worms occurred on gill arch i, 28% on ii, 25% on iii and 18% on iv. this distribution pattern on the introduced salmonid species is the same as reported for its native european host, the brown trou ... | 2008 | 19175205 |
| exposure to a mixture of zinc and copper decreases survival and fecundity of discocotyle sagittata (leuckart) parasitizing juvenile atlantic salmon, salmo salar l. | we assessed the effects of zinc and copper on freshwater monogenean ectoparasites (discocotyle sagittata leuckart) infecting juvenile atlantic salmon (salmo salar l.). exposure to 47 microg/l zinc and 3 microg/l copper reduced survival and fecundity of adult d. sagittata, while egg hatching success was only reduced at high exposure concentrations (2704 microg/l zinc and 164 microg/l copper). parasitized salmon had decreased plasma chloride, but this was negated in infected fish exposed to metals ... | 2010 | 20473654 |