Abomasal nematodes from three Norwegian wild reindeer populations

1987 ◽  
Vol 65 (3) ◽  
pp. 677-680 ◽  
Author(s):  
Karstein Bye

Three separate populations of wild reindeer (Rangifer tarandus tarandus L.) in Norway were examined for the presence of abomasal nematodes. The following six species were recorded: Ostertagia grühneri, Skrjabinagia arctica, Trichostrongylus axei, Teladorsagia circumcincta, Teladorsagia davtiani, and Nematodirus tarandi. Ostertagia grühneri dominated both in prevalence and intensity of infection. Teladorsagia davtiani occurred in only one of the populations investigated, and N. tarandi was found in calves only. Reindeer and sheep grazed the same areas, but no evidence of transfer of parasites from sheep to reindeer was found. All 72 adult reindeer and 10 calves examined during February–April harboured adult abomasal nematodes. The mean intensity of abomasal nematodes was highest in the population with the highest density of reindeer. Reindeer from this population were in poor physical condition. The influence of abomasal nematodes on life-history parameters of the host population is discussed.

Parasitology ◽  
2004 ◽  
Vol 129 (3) ◽  
pp. 363-369 ◽  
Author(s):  
M. J. STEAR ◽  
K. BAIRDEN ◽  
G. T. INNOCENT ◽  
S. MITCHELL ◽  
S. STRAIN ◽  
...  

The number ofTeladorsagia circumcincta4th-stage larvae in naturally infected lambs from a single farm varied among lambs and among different years. Within each year the distribution of 4th-stage larvae among lambs was similar to that expected from a negative binomial distribution. The ratio of 4th-stage larvae to adultT. circumcinctawas low in two years with a low mean intensity of infection but high in two years with a higher mean intensity of infection. The negative binomial distribution is defined by the mean and byk, a parameter that measures dispersion;kwas low when mean infection intensity was low but higher when mean infection intensity was high. Askis an inverse index of overdispersion this indicated that the distribution of 4th-stage larvae was more overdispersed at low levels of infection. In a combined analysis, the number of adultT. circumcinctaand the plasma IgA activity against 4th-stage larvae were both associated with increased numbers of 4th-stage larvae. There was a statistical interaction between the number of adults and IgA activity that moderated their combined effect.


1988 ◽  
Vol 66 (2) ◽  
pp. 475-479 ◽  
Author(s):  
Murray W. Lankester ◽  
Stu Luttich

Fifty-eight percent of woodland caribou (Rangifer tarandus caribou) of the George River herd, Labrador, were infected with up to 110 giant American liver flukes (Fascioloides magna). The prevalence and intensity of infection did not differ between 2 sampling years or between sexes. Prevalence tended to increase with age while intensity did not differ among age groups. Liver weight increased with intensity of infection but condition, as measured by the mean depth of back fat, did not differ between infected and uninfected animals. Caribou must be considered a suitable host of F. magna since the growth and maturation of the parasite and lesions produced in Rangifer resemble those in deer and wapiti.


2008 ◽  
Vol 45 (3) ◽  
pp. 126-129 ◽  
Author(s):  
I. Gomez Villafañe ◽  
M. Robles ◽  
M. Busch

AbstractThe aims of this research were: 1) to determine the helminth parasite fauna of seventy two Rattus norvegicus (Berkenhout, 1769) individuals inhabiting poultry farms in the Pampean region of Argentina; 2) to examine the relationship between parasitism and individual characteristics of the hosts, and 3) to analyze the associations among helminths. The study was carried out in twenty-four poultry farms from autumn 2000 to winter 2001. Nematodes were found in the intestine or caecum rectum of the 74 % of rats and cestodes were found along all the intestine of the 28 % of rats. Heterakis spumosa (Travassos 1914) was a central species, whereas Syphacia muris, Yamaguti 1941, Nippostrongylus brasiliensis (Travassos 1914) and Hymenolepis diminuta (Rudolphi 1819) were satellite species. Helminths do not affect rat survival and growth of rats. Rats parasitized with H. spumosa and H. diminuta were larger and older than non-parasitized rats. The intensity of infection with H. spumosa significantly increased with rat age. Rats parasitized with Nippostrongylus brasiliensis and Syphacia muris did not differ in size and age with respect to non-parasitized ones. The mean intensity of infections per host was 33.74, 74.28, higher than 200, and 3.10 for H. spumosa, S. muris, N. brasiliensis and H. diminuta, respectively. The mean intensity of infection with H. spumosa was higher in summer than in the other seasons, while the higher mean intensity of infection with N. brasiliensis and S. muris occurred in autumn. Infections with Heterakis spumosa and Syphacia muris, and with Syphacia muris and Nippostrongylus brasiliensis were independent; while Heterakis spumosa and Nippostrongylus brasiliensis were negatively associated.


2001 ◽  
Vol 75 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Yang Tingbao ◽  
Liao Xianghua

Studies on the seasonal population dynamics ofNeoechinorhynchus qinghaiensis(Acanthocephala: Neoechinorhynchidae) in its fish hostGymnocypris przewalskii przewalskiiin the Qinghai Lake, China, were carried out with samples taken in May 1991, August 1992, November 1992 and February 1993. Prevalences were higher than 44% in all seasons. The mean intensity of infection was above 124 worms per fish. The maximum intensity of worms recovered from a single fish was 1402 in the autumn of 1992. Differences in the mean abundance, mean intensity and prevalence are not statistically significant relative to season and this is likely to be related to the stable temperatures recorded at the bottom of Qinghai Lake. Over-dispersed distributions ofN. qinghaiensisin the host population, due to heterogeneity and feeding habits, were observed in all seasons. The size composition of both sexes ofN. qinghaiensisshowed males to be less than 3.5 mm and females between 0.5 and 4.25 mm, with the main recruitment phase in the worm populations occurring in the autumn, extending through winter and spring with the lowest recruitment occurring in the summer. The maturation and copulation of worms were mainly focused in the summer season. The sex ratio of female to male was both high in winter (1.51:1) and spring (1.48:1). The higher proportion of females and the change in the worm sex ratio in winter can be attributed to the reduced longevity of male worms. As immature male worms exhibit a higher proportion of the worm population than females in all seasons, further studies are needed to determine if such a situation compensates for the shorter life span of males.


2009 ◽  
Vol 84 (2) ◽  
pp. 199-201 ◽  
Author(s):  
R.W. Ávila ◽  
L.A. Anjos ◽  
U. Gonçalves ◽  
E.M.X. Freire ◽  
W.O. Almeida ◽  
...  

AbstractEndoparasites associated with the small bromelicolous lizard Bogertia lutzae, a poorly studied phyllodactylid inhabitant of north-eastern Brazil, were studied. Fifty-seven specimens collected from the Atlantic Forest of Alagoas state were dissected. Only one species of parasite, the nematode Spauligodon oxkutzcabiensis, was found, with a prevalence of 22.8%. The intensity of infection was 2.62 ± 1.19, and neither the prevalence nor mean intensity differed between the sexes. There was no correlation between lizard body size and intensity of infection. An aggregated pattern of distribution (D = 0.813) of S. oxkutzcabiensis was found in this lizard host population. Bogertia lutzae represents a new host recorded for S. oxkutzcabiensis, a parasite reported for the first time for Brazil.


2019 ◽  
Vol 119 (3) ◽  
pp. 1161-1165
Author(s):  
Paula Dutra Cardoso ◽  
Débora Liliane Walcher ◽  
Priscila da Silva Cadore ◽  
Ana Carolina Beheregaray ◽  
Luis Augusto Xavier Cruz ◽  
...  

Parasitology ◽  
2001 ◽  
Vol 123 (2) ◽  
pp. 211-218 ◽  
Author(s):  
M. J. STEAR ◽  
P. D. ECKERSALL ◽  
P. A. GRAHAM ◽  
Q. A. McKELLAR ◽  
S. MITCHELL ◽  
...  

Fructosamine concentrations reflect protein status and because infection with Teladorsagia circumcincta can induce a relative protein deficiency, we examined the usefulness of fructosamine concentrations as markers of the intensity of infection in naturally infected lambs. Fructosamine concentration was a heritable trait and variation in fructosamine concerntrations was associated with differences in body weight, and a variety of parasitological variables; animals with increased fructosamine concentrations grew more quickly, had increased faecal egg counts in one of the three study years, had decreased pepsinogen concentrations and decreased IgA activity against 4th-stage larvae of T. circumcincta. Fructosamine concentrations were also associated with variation in the subsequent acquisition of nematodes and in the length of adult female T. circumcincta; lambs with increased fructosamine concentrations had fewer nematodes but the mean length of adult female T. circumcincta was longer. Therefore fructosamine concentrations are potentially useful indicators of the severity of nematode infection and may predict magnitude of subsequent infection.


Rangifer ◽  
1985 ◽  
Vol 5 (2) ◽  
pp. 61
Author(s):  
Sven Skjenneberg (ed.)

The thesis Life history characteristics of wild reindeer (Rangifer tarandus tarandus L.) is approved for the Phil.dr's degree at the University of Oslo. The dissertation took place in Oslo November 9. 1985.


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