Number Of Helminth Species Research Articles

PNEUMOCYSTIS CARINII AND HELMINTH PARASITISM IN SHREWS SOREX ARANEUS AND SOREX CAECUTIENS

The prevalence of Pneumocystis carinii was compared in two species of shrews, Sorex araneus and Sorex caecutiens in Finnish Lapland. The overall prevalence of P. carinii in S. araneus was 70% and in S. caecutiens was 17%. The prevalence for S. araneus is the highest reported for wild animals. The interspecific differences in prevalence were significant for all sex and age groups except for adult males. Based on multiway contingency tables (log-linear models), there was no dependence between sex or age of S. araneus and occurrence of P. carinii. In individual S. araneus the intensity of P. carinii was not related to the total number of helminths or the number of helminth species, and no dependence was observed between the presence of P. carinii and various helminth species.

Helminth Infracommunities of the Frogs Rana catesbeiana and Rana clamitans from Turkey Marsh, Michigan

One hundred twenty-seven bullfrogs, Rana catesbeiana, and 120 green frogs, Rana clamitans, collected in July and August 1987 from Turkey Marsh, Michigan, were examined for helminths. Of the 16 helminth species found, Falcaustra catesbeianae had the highest prevalence and mean intensity in bullfrogs. In green frogs, Megalodiscus temperatus had the highest prevalence and Haematoloechus parviplexus had the highest mean intensity. Taxonomically, 1,030 (30.5%) trematodes and 2,348 (69.5%) nematodes occurred in bullfrogs; 2,874 (96.4%) trematodes, 2 (0.1%) cestodes, and 105 (3.5%) nematodes were found in green frogs. The larger and more aquatic of the 2 hosts, R. catesbeiana, had the highest mean number of helminth species, helminth intensity, diversity, and evenness. Adult frogs of both species had a significantly higher mean number of helminth species than did juveniles. Significant correlations existed between the number of helminth species and frog length. Although the helminth communities of Turkey Marsh frogs are isolationist in character, they are more diverse than other helminth communities studied in amphibians.

Sexual Dichromatism in North American Freshwater Fish: Do Parasites Play a Role?

North American freshwater fish were scored for parasites and sexual dichromatism to test the interspecific prediction of the Hamilton-Zuk hypothesis that more sexually dichromatic fish species should harbour more parasites. We used two measures of parasite load, the mean number of helminth species per individual host and the total number of parasite genera reported per host species.Data were collected on 68 species of indigenous, non driadromous North American freshwater fishes

The intestinal helminths of small mammals in the Malaysian tropical rain forest: Patterns of parasitism with respect to host ecology

Helminths of the intestine, liver and bile-duct of 8 species of small mammal from 3 localities in Peninsular Malaysia are reported. The most abundant hosts, Rattus surifer, R. sabanus and Tupaia glis harbour 13, 12 and 10 species of helminth respectively. There is no marked depletion in the number of helminth species per host species in the island locality. Infections with spiruroids, Digenea and cestodes reflect the insectivorous habits of the hosts. Characteristic parasite faunas can be defined. Patterns of parasitism are discussed with respect to the possible nature of the host-parasite relationships.

A Quantitative Analysis of Helminth Infestation in some Passerine Birds found dead on the Island of Skomer

1. Three hundred and eighty three birds belonging to fifteen species found dead from starvation as a result of a severe cold spell on the island of Skomer, between 2nd and 5th January 19G2, were examined for enteric helminths. The age, sex and weight of each bird was determined whenever possible and on dissection, the species, location and number of helminths was recorded.2. Seventeen species of helminths were found, providing sixteen new host records and five new British records.3. In general, changes in the mean number of helminth species and specimens per bird and per infested bird is directly correlated with changes in the percentage incidence of infestation.

Studies on the Helminth Fauna of Alaska. XVIII. Cestode Parasites in Young Anseriformes on the Yukon Delta Nesting Grounds

Anseriformes are susceptible to parasitism by a great number of helminth species. Mature birds often sustain extremely heavy infections of cestodes without apparent adverse effect. Occasional records, largely from incidental observations, indicate that some of these cestode species are acquired early in the life of the host. Little is known of the identity, prevalence, and effect of helminths in very young birds on the nesting grounds. During the latter part of July and early August, 1952, the writer collected 32 emperor geese (Philacte canagica (Sevastianoff) ), 27 cackling geese (Branta canadensis minima Ridgway), 13 spectacled eiders ( Arctonetta fischeri (Brandt) ), and two pintail ducks (Anas acuta tzitzihoa Vieillot) about 20 miles east of Igiak Bay, Yukon delta, Alaska. With the exception of two adult female spectacled eiders (with broods) all birds were downy young from one to three weeks of age. Most of these birds were captured alive and kept in captivity until just prior to autopsy to insure that their parasites would be in the best condition for subsequent morphological study. Examinations were made in the field, usually the same day that the birds were collected. The systematic part of this work includes the description of a new species of cestode of the genus Hymenolepis Weinland, 1858, found in the spectacled eider; two new host records for H. barrowensis Schiller, 1952, with additional notes on the morphology of this cestode; and the description of the scolex (heretofore unknown) of H. stolli Brock, 1941 (from the pintail duck) with a discussion of the taxonomic status of this species. Data on parasite occurrence according to sex and weight of the host are presented in Table I. Some observations concerning parasite-host relations on the nesting grounds as interpreted from this study are discussed.