Gastropod intermediate hosts of lungworms (Nematoda: Protostrongylidae) on a bighorn sheep winter range: aspects of transmission

1990 ◽  
Vol 68 (9) ◽  
pp. 1976-1982 ◽  
Author(s):  
L. A. Robb ◽  
W. M. Samuel
Keyword(s):  
Mule Deer ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Intermediate Hosts ◽  
Gastropod Species ◽  
Winter Range ◽  
Infective Larvae ◽  
Third Stage ◽  
Inherent Problem

A study of the gastropod intermediate hosts of the lungworms Protostrongylus stilesi and Protostrongylus rushi was conducted on a bighorn sheep (Ovis canadensis canadensis) winter range in southwestern Alberta, 1984–1985. Over 7000 gastropods were examined. Seven gastropod species were infected with Protostrongylus-type larvae: the predominant intermediate hosts were Euconulus fulvus (6.8% infected), Vertigo gouldi (5.6%), and Vertigo modesta (3.2%). Prevalence of third-stage (infective) larvae was highest in September and April, coinciding with use of the winter range by bighorn sheep. An index of lungworm availability to sheep was highest in autumn in the margins of aspen copses and in spring in the grassy openings. Copses were used extensively by sheep in autumn, and open areas were used in the spring. Presence of a mule deer (Odocoileus h. hemionus) lungworm, Orthostrongylus macrotis, was an inherent problem.

Niche relationships within a guild of ungulate species in Yellowstone National Park, Wyoming, following release from artificial controls

1994 ◽  
Vol 72 (8) ◽  
pp. 1383-1394 ◽  
Author(s):  
Francis J. Singer ◽  
Jack E. Norland
Keyword(s):  
Cervus Elaphus ◽  
Rank Order ◽  
Mule Deer ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Bison Bison ◽  
Exclusion Principle ◽  
Antilocapra Americana ◽  
Artemisia Frigida ◽  
Niche Relationships

Niche relationships and diet overlaps were compared among elk (Cervus elaphus), bison (Bison bison), bighorn sheep (Ovis canadensis), mule deer (Odocoileus hemionus), and pronghorn antelope (Antilocapra americana) between 1967–1970 and 1986–1988, a period when total ungulate numbers nearly tripled on Yellowstone's northern range. Ungulate species ratios on Yellowstone's northern winter range during the latter period were 100 elk : 10 mule deer : 3 bison : 2 pronghorns : 1 bighorns. Elk numbers were positively correlated to bison, mule deer, and pronghorn numbers (r2 = 0.76, 0.97, and 0.48, respectively, P < 0.01). Few other changes in habitat use or habitat overlap occurred, and diets for only 2 of the 10 species pairs, elk-bighorn (Spearman's rank order coefficient (RHO) = 0.55, P < 0.05) and mule deer – pronghorn (RHO = 0.64, P < 0.05), were significantly associated with each other. Bison consumed more grass and fewer sedges, mule deer more fringed sage (Artemisia frigida) and more rabbit-brush (Chrysothamnus spp.), and bighorn sheep more grasses and fewer sedges, while pronghorns ate less saltsage (Atriplex nuttalli) but more big sagebrush (Artemisia tridentata) during 1986–1988 than during 1967–1970. Bison expanded their range and bison and bighorn sheep used a wider variety of habitats. We found little evidence of change in competitive interactions between ungulate species. A few diet and habitat overlaps increased, the opposite of the prediction from the competitive exclusion principle amongst species, suggesting that intraspecific competition was more important. Several explanations are proposed for the lack of changes in niche relationships during a period of near tripling in density of the ungulate guild.

SEROPREVALENCE OF TWO BABESIA SPP. ISOLATES IN SELECTED BIGHORN SHEEP (OVIS CANADENSIS) AND MULE DEER (ODOCOILEUS HEMIONUS) POPULATIONS IN CALIFORNIA

1995 ◽  
Vol 31 (4) ◽  
pp. 467-471 ◽  
Author(s):  
Anne M. Kjemtrup ◽  
John W. Thomford ◽  
Ian A. Gardner ◽  
Patricia A. Conrad ◽  
David A. Jessup ◽  
...  
Keyword(s):  
Mule Deer ◽  
Odocoileus Hemionus ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Babesia Spp

Distribution and abundance of terrestrial gastropods on a winter range of bighorn sheep in southwestern Alberta

1982 ◽  
Vol 60 (11) ◽  
pp. 2633-2640 ◽  
Author(s):  
D. A. Boag ◽  
W. D. Wishart
Keyword(s):  
Relative Abundance ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
The Other ◽  
Deciduous Tree ◽  
Annual Species ◽  
Vegetative Cover ◽  
Terrestrial Gastropods ◽  
Winter Range ◽  
Forested Areas

Living specimens of 15 species of terrestrial gastropods (14 snails and 1 slug) were collected on a series of plots located in a variety of habitats associated with a winter range of bighorn sheep (Ovis canadensis) in southwestern Alberta. Four species of snails (Vertigo gouldi, Discus cronkhitei, Vitrina alaskana, and Euconulus fulvus) constituted ca. 85% of all living specimens recorded in 1979, 1980, and 1981. However, the relative abundance of the last three species changed markedly between years. Based on the size of living individuals recovered over the snow-free season, only one snail (Vitrina alaskana) and the slug (Deroceras laeve) appeared to be annual species; the other common snails appear to live more than 1 year. The distribution of gastropods was correlated with the vegetative cover; maximum abundance was found within forested areas where deciduous tree or shrub growth was a major component of the canopy. The implications of the distribution and abundance of these molluscs for the transmission of lungworms to bighorn sheep is discussed.

scholarly journals Declines of Bighorn Sheep, Ovis canadensis, on Deteriorating Winter Range in Jasper National Park, Alberta, 1981-2010

2009 ◽  
Vol 123 (2) ◽  
pp. 157 ◽  
Author(s):  
Dick Dekker
Keyword(s):  
Cervus Elaphus ◽  
National Park ◽  
Full Range ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Athabasca River ◽  
Jasper National Park ◽  
Winter Range ◽  
Salsola Kali ◽  
Average Annual Precipitation

Bighorn Sheep (Ovis canadensis) wintering in the lower Athabasca River valley of Jasper National Park, Alberta, were monitored from 1981 to 2010 by recording maximum band sizes per annum on two traditional but separate sheep ranges. In study area #1, the ram band declined significantly from a 20-year mean of 18 in the period 1981-2001 to a 5-year mean of 11 in the period 2001-2006, with a slight recovery in 2006-2010. Ewes in area #1 dwindled from a mean of 20 in the period 1981-1995 to zero in the period 1995-2010. In area #2, the ewe band dropped significantly from a mean of 40 in the period 1981-2001 to 24 in the period 2001-2010. The declines in area #1 coincided with an invasion of Russian Thistle (Salsola kali). Range conditions in area #2 deteriorated following four years with lower than average annual precipitation. The mean lamb:ewe ratio in area #2, pooled for 29 years, was 22:100 (n = 646). The sheep were protected from hunting, but were subject to a full range of indigenous carnivores. However, predation did not appear to be the primary cause of the declines, nor was competition for forage with American Elk (Cervus elaphus).

The life-cycle of the flatfish nematode Cucullanus heterochrous

2000 ◽  
Vol 74 (4) ◽  
pp. 323-328 ◽  
Author(s):  
M. Køie
Keyword(s):  
Life Cycle ◽  
Larval Stage ◽  
Post Infection ◽  
Gadus Morhua ◽  
Developmental Stages ◽  
Experimental Studies ◽  
Fourth Stage ◽  
Intermediate Hosts ◽  
Infective Larvae ◽  
Third Stage

AbstractMature specimens of Cucullanus heterochrous Rudolphi, 1802 (Nematoda: Cucullanidae) were obtained from the intestine of the flounder, Platichthys flesus, from Danish waters. Eggs embryonate in seawater but do not hatch. Fully developed larvae pressed out of eggs are 430 μm long with amphids and dereids and enclosed within the cuticle of a previous larval stage. Infective larvae are believed to be in their third stage. Experimental studies showed that the polychaetes, Nereis spp., Scoloplos armiger, Brada villosa and Capitella sp., may act as intermediate hosts. In N. diversicolor the larvae increase their length to 1 mm within four weeks (15°C) without moulting. Experimental infections showed that larvated eggs are not infective to fish, whereas >550 μm long larvae from polychaetes survived in 4–24 cm long flounders and plaice, Pleuronectes platessa. Third-stage larvae 550 μm to 1.1 mm long were found in the submucosa of the intestine one week post infection. At a length of about 800 μm to 1.4 mm they moult to fourth-stage larvae. Fourth-stage larvae, immature and mature worms occur in the intestine and rectum. Fourth-stage larvae and adults survived experimental transfer from one flounder to another. Similar developmental stages survived for two weeks in the intestine of experimentally infected cod, Gadus morhua.

The effect of temperature on rates of development of larval Protostrongylus spp. (Nematoda: Metastrongyloidea) from bighorn sheep, Ovis canadensis canadensis, in the snail Vallonia pulchella

1985 ◽  
Vol 63 (6) ◽  
pp. 1445-1448 ◽  
Author(s):  
J. Samson ◽  
J. C. Holmes
Keyword(s):  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Effect Of Temperature ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Degree Days ◽  
Rate Of Development ◽  
Slow Development ◽  
Third Stage ◽  
Stage Development

The rate of development of Protostrongylus stilesi and (or) Protostrongylus rushi in the intermediate host Vallonia pulchella was related linearly to temperature between 10 and 30 °C. The temperature threshold was 8 °C and the thermal constant was 305 degree-days. Infected snails kept at 10 °C for several days and then transferred to 25 °C produced third-stage larvae faster than expected. Rates of development of Protostrongylus spp. applied to field conditions indicated that most of the first- to third-stage development occurs during the summer, very slow development takes place in the autumn or the spring, and none occurs over the winter. These data reinforce the hypothesis formulated by D. A. Boag and W. D. Wishart that snails on the bighorn sheep wintering grounds are responsible for transmission of the lungworms to sheep in autumn.

scholarly journals Infectivity of gastropod-shed third-stage larvae of Angiostrongylus vasorum and Crenosoma vulpis to dogs

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
William Robbins ◽  
Gary Conboy ◽  
Spencer Greenwood ◽  
Roland Schaper
Keyword(s):  
Tap Water ◽  
Natural Infection ◽  
Angiostrongylus Vasorum ◽  
Intermediate Hosts ◽  
Red Foxes ◽  
Romaine Lettuce ◽  
Crenosoma Vulpis ◽  
Artificial Digestion ◽  
Third Stage ◽  
Limax Maximus

Abstract Background Metastrongyloid parasites Angiostrongylus vasorum and Crenosoma vulpis infect wild and domestic canids and are important pathogens in dogs. Recent studies indicate that gastropod intermediate hosts infected with various metastrongyloids spontaneously shed infective third-stage larvae (L3) into the environment via feces and mucus under laboratory conditions. Shed L3 retain motility up to 120 days, but whether they retain infectivity was unknown. Methods To assess the infectivity of shed L3, the heart/lungs of six red foxes (Vulpes vulpes) were obtained from trappers in Newfoundland, Canada. Lungs were examined for first-stage larvae (L1) by the Baermann technique. A high number of viable A. vasorum L1 and a low number of C. vulpis L1 were recovered from one fox; these were used to infect naïve laboratory-raised Limax maximus. L3 recovered from slugs by artificial digestion were fed to two naïve purpose-bred research beagles (100 L3/dog). L1 shed by these two dogs was used to infect 546 L. maximus (2000–10,000 L1/slug). L3 shedding was induced by anesthetizing slugs in soda water and transferring them into warm (45 °C) tap water for at least 8 h. Shed L3 recovered from slugs were aliquoted on romaine lettuce in six-well tissue culture plates (80–500 L3/well) and stored at 16 °C/75% relative humidity. Four naïve research beagles were then exposed to 100 L3/dog from larvae stored for 0, 2, 4, or 8 weeks, respectively, after shedding. Results All four dogs began shedding C. vulpis L1 by 26–36 days post-infection (PI). All four dogs began shedding A. vasorum L1 by 50 days PI. Conclusions L3 infectivity for the definitive host was retained in both metastrongyloids, indicating the potential for natural infection in dogs through exposure from environmental contamination. As an additional exposure route, eating or licking plant or other material(s) contaminated with metastrongyloid L3 could dramatically increase the number of dogs at risk of infection from these parasites. Graphic Abstract

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