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K Skirnisson

Publications and source records attributed to K Skirnisson.

10 recordsLinked to original sources

The third newly discovered Eimeria species (Protozoa: Eimeriidae) described from wild reindeer, Rangifer tarandus, in Iceland.

Fecal samples from 56 adult reindeer from eastern Iceland were examined for coccidian parasites. One Eimeria species was found in an 8-year-old male. Prevalence of infection was 1.8%; oocyst per gram (opg) value was 150. The coccidium was identified and described as a new species. The sporulated oocysts are ellipsoidal and average size is 30.0 x 21.1 microm. The oocyst has two distinct walls. Wall thickness is approximately 1.0 microm, and the outer wall, approximately four-fifths of total thickness, is generally smooth and appears bicoloured. The outermost portion is light blue, and the innermost portion, yellow to pale brown. The inner wall is dark brown. Oocysts contain a prominent polar granule but are devoid of a micropyle. Oocysts enclose four spindle-shaped sporocysts with a rounded end opposite to the Stieda body. The average size of sporocysts is 15.3 x 6.5 microm. Sporocysts contain a granular sporocyst residuum that usually forms a cluster between the sporozoites and one large refractile body in each sporozoite.

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Description of a new Eimeria species and redescription of Eimeria mayeri (Protozoa: Eimeriidae) from wild reindeer Rangifer tarandus in Iceland.

Altogether, 195 fecal samples of reindeer calves (Rangifer tarandus) were collected from the ground in 3 distinct areas in eastern Iceland, where geographically isolated reindeer populations graze during the summer months. The samples were examined for coccidian parasites. Two species were found, and all infections were monospecific. Eimeria mayeri was found in calves in all sampling areas, with 1-4% prevalence and 450-167,700 oocysts per gram (opg). The sporulated oocyst lacks a polar granule but has an inconspicuous micropyle, and a small Stieda body is present on sporocysts, which are ovoid but not pointed as reported in the original description. The other coccidian, found in single calves in 2 of the 3 areas (prevalence 1 and 4%, 150 and 500 opg, respectively) is described here as a new species. The oocysts are ovoid, average 34.9 x 27.6 microm, and have 2 distinct walls. Wall thickness is approximately 1.9 microm, and the outer wall, approximately 3/4 of total thickness, is generally smooth and appears bicolored. The outermost portion is pale red and the innermost portion yellow to pale brown. The inner wall is grey to dark brown and separated from the outer wall by a dark brown line. Oocysts contain a prominent micropyle, approximately 5 microm, and enclose 4 spindle-shaped sporocysts, slightly pointed at the end opposite the Stieda body. Average size of sporocysts is 18.6 x 9.2 microm. Sporocysts contain granular sporocyst residuum and usually 2, sometimes 1, large refractile bodies in each sporozoite.

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Digeneans from intertidal molluscs of SW Iceland.

The fauna of digenean daughter-sporocysts, rediae, cercariae and metacercariae infecting molluscs Littorina spp., Onoba aculeus. Nucella lapillus and Epheria vincta has been studied in the Skerjafjordur and Grindavik regions of SW Iceland. In total, intramolluscan stages of 19 digenean species were recorded; 14 of them are new for Iceland and one of them, a microphallid named Cercaria islandica I, was unknown. A description of this new microphallid cercaria is provided. In addition, the identification and separation of the intramolluscan stages of some microphallid, renicolid and echinostomatid species are discussed. Consideration is given to difficulties encountered when identifying digenean species found on the coasts of European countries. Problems have arisen largely because larval and adult stages have been described and named independently and in isolation, synonyms are common and many "definitive" descriptions are inadequate or incomplete.

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Schistosome cercariae as the causative agent of swimmer's itch in Iceland.

During late summer in 1995 to 1997, repeated outbreaks of maculopapular skin eruptions were noted on the legs of children after wading in the pond in the Family Park in Laugardalur, Reykjavík, Iceland. Clinical symptoms developing on the legs resembled those of cercarial dermatitis. An examination of Lymnaea peregra snails from this pond and from the adjacent Lake Tjornin resulted in detection of previously undescribed schistosome cercariae. This is the first report of schistosomes in Iceland and also the most northern occurrence of these parasites in Europe.

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Histological, histochemical, and fine structural observations on the lymph node of the common seal (Phoca vitulina) and the grey seal (Halichoerus grypus).

BACKGROUND: The recent seal death epizootic prompted interest in their immune system, for which no current morphological data were available. METHODS: Lymph nodes from adult harbor seals (Phoca vitulina) and grey seals (Halichoerus grypus) were investigated by light microscopy, electron microscopy, and lectin histochemistry. RESULTS: No significant differences in the lymph node morphology were found between the two species, and the overall organization of the nodes comprises of capsule, trabeculae, cortex, paracortex, and medulla. Capsule and trabeculae are composed of tightly packed collagen and elastic fibrils and are rich in fibroblasts, myofibroblasts, and smooth muscle cells. Unmyelinated nerve fibers are common. The cortex contains numerous secondary follicles with well-developed germinal centers and paracortical areas with high endothelial venules. Antigen-presenting cells and phagocytic macrophages were abundantly present. The medullary cords contain numerous plasma cells. Fibroblastic reticulum cells are common throughout the parenchyma and transverse the sinus. Marginal, radial, and medullary sinuses are lined by littoral cells. The visceral lining of the sinuses is marked by macrophages and by numerous mast cells. CONCLUSIONS: The morphology of seal lymph nodes does not differ significantly from that of terrestrial mammals. Earlier functional conclusions concerning seal lymph nodes are substantiated by this morphological study.

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Infection studies with canine distemper virus in harbour seals.

Infection studies in harbour seal (Phoca vitulina) were conducted with the Snyder-Hill strain of canine distemper virus (CDV) that is virulent for dog and mink. The inoculated seals showed clinical symptoms which were to some degree similar to those observed in CDV infections of sensitive species of carnivores. Viral replication in lymphoid cells was followed by an extended period of immunosuppression. The results did not provide conclusive evidence for viral replication in surface epithelia of seals, and accordingly no spread of the infection to contact seals and mink was demonstrated. The pathogenicity of the infection did not increase upon a second viral passage in seal. The serological data showed that CDV-infected seals mounted an early virus specific antibody response. Overall, the results indicated that the harbour seal was not especially sensitive to CDV infection. The differences in the in vivo biological properties of CDV and PDV add to the distinction between these viruses at the genomic and antigenic levels.

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Histological investigations on the thyroid glands of marine mammals (Phoca vitulina, Phocoena phocoena) and the possible implications of marine pollution.

In 1988 and 1989, thousands of harbor seals (Phoca vitulina) died in the North Sea from phocine distemper infection. The morphology of thyroid glands from 40 harbor seals found dead on the North Sea coastlines of Schleswig-Holstein, Federal Republic of Germany, during an epizootic of phocine distemper, was compared with the morphology of thyroid glands from five healthy harbor seals collected in Iceland. Thyroid glands from seven harbor porpoises (Phocoena phocoena) found dead in 1990 on the North Sea coastlines also were evaluated. Colloid depletion and fibrosis were found in the thyroid glands of harbor seals which died during the epizootic, but not in animals from Iceland. Thyroid glands of the porpoises showed similar lesions, but to a lesser degree, than those observed in the North Sea seals.

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A safe method for repeatedly immobilizing seals.

Phocid seals were immobilized safely and repeatedly, using a combination of ketamine and diazepam at mean IM or IV dosages of 1.5 mg/kg and 0.05 mg/kg, respectively. Induction and recovery were smoother than with ketamine used alone. Experimentally induced pneumonia did not alter the effects of the drugs, thus attesting to the safety of the ketamine-diazepam combination.

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