[Fauna and distribution of nematodes from the suborders spirurata and filariata parasitizing cattle in Dagestan, from the perspective of vertical zoning].

Cattle of Dagestan are infested with several nematode species from the suborders Spirurata and Filariata, and extensiveness of the invasion depends greatly on the altitude above sea level. Level of infestation with Thelazia rhodesi, Th. gulosa, and Th. skrjabini is 38% in plains, 20% in submontane, and 5% in mountain zone. The same tendency is observed for the species Gongylonema pulchrum--45, 22, and 10%, respectively. Infestation with Setaria labiato-papillosa is 27.3% on average. Infestation with Onchocerca gutturosa and O. lienalis is 11% in plains and 3% in mountain and submontane zones; infestation with Stephanofilaria assamensis and S. stilesi in these zones is 18 and 5%, respectively. In mountain localities situated higher than 1000 m a. s. l. only G. pulchrum is occurred.

The relationship between polychlorinated biphenyls in blubber and levels of nematode infestations in harbour porpoises, Phocoena phocoena.

Post-mortem examinations of harbour porpoises, Phocoena phocoena, regularly reveal heavy parasitic worm burdens. These same post-mortem records show varying levels of polychlorinated biphenyls (PCBs) accumulating in the blubber of porpoises. Although a number of papers have documented geospatial and temporal changes of PCBs and their detrimental effects on marine mammal health, as yet none have examined their role in determining nematode burdens in wild marine mammal populations. Using a data set consisting of harbour porpoises stranded in the UK between 1989 and 2002, we found a significant, positive association between PCB levels and nematode burdens, although the nature of the relationship was confounded with porpoise sex, age and cause of death. It was also apparent that individuals with the heaviest infestations of nematodes did not have the highest PCB level: while PCBs are important, they are clearly not the sole determinants of nematode burdens in wild populations of the harbour porpoise around the UK.

Ichthyouris voltagrandensis n.sp. (Nematoda: Pharyngodonidae) from Myleus tiete Eigenmann & Norris, 1900 (Osteichthyes: Characidae) in the Volta Grande Reservoir, MG, Brazil

The present work studied helminth parasites of "pacu-manteiga", Myleus tiete (Osteichthyes: Characidae) from Volta Grande Reservoir, MG, Brazil. Fishes with 142.6 Ý 24.7 g weight and 17.3 Ý 1.0 cm total length were collected. Five out six analysed fish (prevalence 83.3 percent) were parasitized in the intestine with an average of 535.6 Ý 334.6 oxyurid nematodes per fish. The helminth was identified as Ichthyouris voltagrandensis n.sp. (Nematoda: Pharyngodonidae). It differs from I. brasiliensis (Moravec et al., 1992a) by the absence of lateral alae, higher measures of tail and caudal alae of males, esophageal isthmus length, distance of excretory pore from anterior end and spicule length. In addition, eggs were provided by two long filaments in just one pole and by the first time the authors observed flagellate spermatozoa from dissected males. The authors exposes comparative table of measures of the five described species of the genus Ichthyouris

[Endoparasitic infections in sheep from the Swabian Alb]. / Ein Beitrag zur Kenntnis des Endoparasitenbefalls der Schafe auf der Schwäbischen Alb.

The endoparasite fauna of 59 slaughtered sheep (30 lambs, 29 ewes) from the Swabian Alb, Germany, was examined. One species of trematodes, 3 species of cestodes, 29 species of nematodes (23 species of gastro-intestinal and 6 species of lung nematodes), 1 species of arthropodes and 1 species of protozoa were recorded. All animals were infected with Dicrocoelium dentriticum as well as gastro-intestinal and lung nematodes, 45.8% with Moniezia spp., 15.3% with Cysticercus tenuicollis, 55.9% with Oestrus ovis and 11.9% with Sarcocystis gigantea. The most important gastro-intestinal nematodes were Ostertagia circumcincta and Cooperia curticei, which were recorded in all sheep, Ostertagia trifurcata and Chabertia ovine (98.3% each), Oesophagostumum venulosum (96.6%), Nematodirus filicollis (81.4% each), Ostertagia pinnata (78.0%), Trichuris ovis and Trichostrongylus colubriformis (76.3% each). The ewes harboured more abomasal and small intestinal nematodes (1819 and 3702) than the lambs (695 and 1730), which haboured more large intestinal nematodes (177) than those (56). The most often recorded lungworms were Cystocaulus ocreatus (74.6%) and Muellerius capillaris (72.9%), followed by Neostrongylus linearis (57.6%), Dictyocaulus filaria (50.8%), Protostrongylus brevispiculum (37.3%) and Protostrongylus rufescens (28.8%). The ewes carried higher lungworm burdens than the lambs.

Comparative analysis of two methods used to show interspecific associations in naturally acquired parasite nematode communities from the abomasum of ewes.

The aim of our study was to compare a multivariate and a univariate method to evaluate the associations between nematode species in natural infections. We used a data set based on the 3-year study of the community of abomasal nematodes in ewes of the middle-Atlas region of Morocco. Frequency data (percentage of each species in the individual host community) were processed by principal component analysis. Euclidean distances between species (D2) were calculated from projections of principal component analysis on three axes and compared to a bivariate estimate (1 - correlation coefficient R). Low distances were recorded between morphs of the same species (Teladorsagia circumcincta and T. trifurcata, for example), which indicates a positive association. Only two species, Trichostrongylus axei and T. circumcincta, were negatively associated having D2 values much over 1. The distances D2, i.e., multivariate measure of association intensity were similar in most cases to 1- R estimates, indicating probably the absence of strong multispecies association. The D2 fitted a Motomura geometric progression model indicating that associations were arranged in a continuum from low to high values, but they did not depart much from what could be expected from random associations for most species. The D2 interest is mostly to relate associations with environmental variables, and comparing with 1 - R, to assess the degree of interaction in the community.

Host specificity of sheep and cattle nematodes in São Paulo state, Brazil.

The trial was carried out to investigate parasite host specificity and to analyse the dynamics of infection with nematodes parasitizing sheep and cattle raised together or separately in São Paulo state, Brazil, and, also to clarify doubts about the systematics of species of the genus Haemonchus on the basis of cytological and morphological studies. Ten steers and 32 ewes were randomly assigned to three paddocks (P), as follows: P1, 5 steers; P2, 5 steers and 16 ewes; and P3, 16 ewes. The animals remained on these paddocks in continuous grazing throughout the trial (1-yr period). Faecal exams and larvae counting on pasture were performed fortnightly. Once a month two tracer lambs were placed in each paddock, while two tracer calves were also placed, but only in the eighth month of the trial. All these animals were slaughtered for worm identification and counting. At the end of the trial, one steer and one ewe from P2, which showed high faecal egg counts, were also slaughtered for the same purpose. Nematodes identified cytogenetically as H. placei presented spicule hooks longer than those identified as H. contortus. The following distribution of parasites in cattle and sheep was observed: Bunostomum phlebotomum, H. similis, Mammomonogamus laryngeus strongly adapted to cattle, H. placei and Cooperia punctata more adapted to cattle than to sheep, Trichostrongylus axei and C. spatulata apparently more adapted to cattle, T. colubriformis strongly adapted to sheep, H. contortus more adapted to sheep than to cattle and C. curticei apparently more adapted to sheep. Cross-infection was shown to occur involving some species, however, with time the animals apparently eliminate the species that are not well adapted to them. Therefore, grazing management systems using cattle and sheep appear to be promising for worm control in southeastern Brazil.

The epidemiology of gastrointestinal nematode infections in communal cattle and commercial beef cattle on the highveld of Zimbabwe.

An epidemiological study of gastrointestinal nematode infections of cattle was conducted on the highveld of Zimbabwe from June 1993 to May 1995. The study was carried out in two communal areas, two conventional beef farms and two commercial beef farms with irrigated pastures. On all farms/areas, faecal egg counts were low (< 500 eggs per g faeces) during the dry season. During the rainy season faecal egg counts were highest in communal areas and lowest in conventional beef farms. Those of irrigated farms had intermediate values. During the dry season pasture larval counts were low in irrigated pastures and conventional beef farms and virtually zero in communal areas. They increased and peaked during the rainy season, coinciding with the egg count peaks. Worm burdens of necropsied cattle indicated that 100% of the animals were infected with nematodes. The important species were Cooperia pectinata, C. punctata, Haemonchus placei, Trichostrongylus axei and Oesophagostomum radiatum in all farms/areas and Ostertagia ostertagi in a beef farm with irrigated pastures. Haemonchus survived the dry season as inhibited early fourth stage larvae whereas Cooperia and Trichostrongylus survived as adults.

Epidemiological aspects of lungworm infections of goats in Morocco.

The results of a survey of lungworm infections in goats in the Middle Atlas and Rabat areas in Morocco during 1990-1992 are reported. Five species were recorded: Dictyocaulus filaria, Protostrongylus rufescens, Cystocaulus ocreatus, Muellerius capillaris and Neostrongylus linearis. The parasitological profile of protostrongylid species was represented by Muellerius (69-78%), Protostrongylus (16-25%) and Cystocaulus (5-6%) in the Rabat and Middle Atlas areas. Neostrongylus was virtually non-existent (under 1%) in both regions. Multigeneric infection involving several species of lungworms reached 54% in Rabat and 88% in Middle Atlas. Dictyocaulus infection of goats does not appear to be a serious problem. Infection rates of 40% and 50%, and average worm burdens of three and five worms per kid and adult goat were recorded in autumn in the Rabat area. A similar pattern was noted in Middle Atlas. In contrast, the incidence of small lungworm infections in goats is widespread at levels likely to be of economic significance. The level of infection was considerably higher than the Dictyocaulus infection and the infection rate was virtually 100% in both age groups in the two areas. The overall worm burdens averaged 77.03 +/- 22.6 parasites per adult goat and 44.16 +/- 16.3 per kid in the Rabat area, whereas the corresponding figures in Middle Atlas were 51.48 +/- 16.65 and 34.06 +/- 2.69 worms. The periods of high risk of infection by small lungworms were autumn, early winter and late spring-early summer. However, the heaviest infection by adult worms and the highest larval excretion were observed in late autumn and winter when molluscs were heavily infected. The periparturient period seemed to exert a positive influence on protostrongylid larval production. The output of first stage larvae (L1) of lungworms was significantly higher in goats than in sheep. Thus, goats may play a greater role in pasture contamination. The epidemiological factors influencing the seasonal fluctuations of lungworms are discussed and a timetable of recommended treatments is suggested.