The histopathological effects of Taenia crassiceps infection or T. crassiceps metacestode factor inoculation on the mouse ovary were determined using six female mice in three groups: infected mice, mice inoculated with the metacestode factor and control mice. The control group was subcutaneously inoculated with healthy peritoneal fluid. The infected group was intraperitoneally inoculated with 40 T. crassiceps metacestodes, and the metacestode factor group was subcutaneously inoculated with T. crassiceps metacestode factor (MF). Light and electron microscopy and TUNEL (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labelling) assays revealed a significant increase in ovarian follicular atresia (predominantly in antral/preovulatory stages of development), oocyte degeneration (P< 0.05), and a decrease in the amount of corpus luteum in follicles of mice infected and inoculated with MF compared with the control group. Significant abnormalities of the granulosa cells and oocytes of the primordial, primary and secondary ovarian follicles occurred in both treated mouse groups (P< 0.05) compared with no degeneration in the control group. These pathological changes in female mice either infected with T. crassiceps metacestodes or inoculated with T. crassiceps MF may have consequences for ovulation and fertility.

The spiral intestines of a total of 16 round fantail stingrays Taeniurops grabata from the Mediterranean Sea off Tunisia were examined for cestodes. A new genus is erected in the Anthocephaliidae (Rhinebothridea) as Alveobothrium gen. n., with Alveobothrium grabatum sp. n. as its type species; the new genus differs from the other genera in the order in that its members possess bothridia with an apical sucker, marginal loculi and multiple staggered rows of facial loculi. Alveobothrium zarzisense sp. n. is also described. The species differ in the number of marginal loculi and in proglotid anatomy. Another anthocephaliid belonging to the genus Anthocephalum is also described from T. grabata. Anthocephalum jeancadenati sp. n. is most similar to A. alicae and A. michaeli, but differs in size of terminal proglottid and number of proglottids. All these new species are also found in formalin-preserved cestodes from T. grabata collected at Gorée Island (Senegal) between 1946 and 1954 by the French ichthyologist J. Cadenat and conserved in the personal collection of the late L. Euzet. The presence of the same rhinebothriideans species parasitizing T. grabata in both the Mediterranean (Tunisia) and the eastern Atlantic (Senegal) is discussed.

A literature survey was undertaken in order to draw up a definitive list of helminth parasites of the wolf, Canis lupus. From 27 papers a total of 72 helminth species from 40 genera were recorded that infect wolves, of which 93% were identified from the gastrointestinal tract at necropsy. They comprised 28 species of nematode, 27 species of cestode, 16 species of trematode and one acanthocephalan. Of these, 46 species were able to be included in further meta-analysis of prevalence data derived from 25 publications for which the total number of wolves examined was 1282 (1066 from Nearctic populations, and 216 from the Palaearctic region). These two populations were further subdivided into three relevent ecosystems or biomes, i.e. temperate/montane (n=216), boreal (n=805) or tundra (n=261). The meta-analysis of relative prevalence indicated the most common helminth species to be the tapeworm Taenia hydatigena, which occurred at relative rates of >30% for either zoogeographic region as well as in each of the three biomes. The related tapeworm, Echinococcus granulosus also exhibited high meta-prevalence (>19%) in all host biomes. The hookworm Uncinaria stenocephala was the most prevalent nematode species by meta-analysis (meta-prevalence 44.9%) in the temperate/montane biome, while the ascarid Toxascaris leonina was the dominant helminth species (meta-prevalence 73.9%) in the tundra wolf populations. Trematodes in the genus Alaria were the dominant fluke (meta-prevalence 3–5%) in all biomes. Analysis of published studies for helminth biodiversity using the Shannon-Wiener index based on species number and meta-prevalence by region or biome, indicated that highest helminth diversity occurred in wolf populations of the temperate/ montane biome (Palaearctic), and was lowest in tundra wolf populations of the Nearctic (P<0.05). Helminth species assemblage in European wolf populations was therefore at least as great or more varied than was recorded for the larger less disturbed wolf populations of North America.

Didelphis albiventris is the opossum with the largest geographic distribution in Brazil and has a wide spectrum of helminth parasites. This study aimed to describe the species composition and analyse the structure of helminth communities of D. albiventris in two extremes of the Atlantic Forest in Brazil. The influence of host sex, body mass, age, helminth species richness and locality on the abundance and prevalence of the most prevalent helminth species was investigated. Ninety-five per cent of the animals were infected with at least one species. Nine helminth species were found: the nematodes Aspidodera raillieti, Cruzia tentaculata, Trichuris didelphis and Trichuris minuta in the large intestine; Turgida turgida in the stomach; Travassostrongylus orloffi and Viannaia hamata; and the trematodes Brachylaima advena and Rhopalias coronatus in the small intestine. Three helminth morphospecies were also recovered: the nematodes Hoineffia sp. and Viannaia sp. and a cestode in the small intestine. Cruzia tentaculata and V. hamata were the species with the highest mean abundances and intensities, while the most prevalent species were A. raillieti, C. tentaculata, T. turgida and V. hamata, forming the central nucleus of the helminth component community. The analysis of the helminth metacommunity structure indicated a Gleasonian pattern for the total set of infracommunities, corroborating the beta diversity indices, which indicated more species replacement than loss between localities and infracommunities, although at a low level. The results indicated a stronger influence of host attributes than geographical distance on the community structure.

The genus Ashworthius contains the following species: A. pattoni Le Roux, 1930 (genotype) from Tragelaphus scriptus sylvaticus (bush buck), A. sidemi Schulz, 1933 from Cervus nippon hortilorum (Sika deer) and C. elaphus asiaticus (red deer), A. martinagliai Ortlepp, 1935 from Bosclaphus tragocamelus (Nilgai) and A. lerouxi Diaouré, 1964 from Syncerus coffer nanus (dwarf forest buffalo). Pike (1969) revised the genus and redescribed A. lerouxi from Syncerus caffer coffer (African buffalo). He gave accounts of other valid species and amended the generic diagnosis.

A new species Renicola glacialis sp. nov., belonging to the trematode genus Renicola, is described.

The species is distinguished from most other renicolids by its relatively large size. Two other species within this size range have been recorded; while it is easy to separate R. glacialis from one of these species (R. goliath Wright, 1957) the poor description of the other (R. secunda Skrjabin, 1924) renders a detailed comparison meaningless. However, the differences in host and geographic location between this and R. glacialis are considered sufficiently great to justify the erection of a new species.

The pathology of R. glacialis is discussed; recently established worms elicit only a slight host tissue response, but older infections are invested by a thick connective tissue sheath. The latter shows maximum development around dead worms and is accompanied by pronounced eosinophilia.

Attention has been drawn to the use of the excretory vesicle as a diagnostic character. Four distinctly different forms have been described, and it is suggested that this character, together with certain other morphological features, would provide a useful key for the identification of renicolids once such information is available.

Gyrodactylus sphinx Dmitrieva & Gerasev, 2000 is the only species of Gyrodactylus originally described from Aidablennius sphynx (Valenciennes) in the Black Sea. In the present study, monogeneans similar to G. sphinx are reported from the same host and from two other species of Blenniidae from the Black Sea, as well as from the Mediterranean Sea. This study aims to verify the taxonomic status of the specimens found in different hosts and localities, other than the type ones of G. sphinx. Twenty-two measurements of the haptoral structures of 169 gyrodactylids were used for the morphological study. Morphometric variability between different samples was analysed using analysis of variance, multivariate analysis of variance (MANOVA) and principal component analysis (PCA). Molecular studies were carried out using the nuclear internal transcribed spacer 2 and 5.8S ribosomal DNA regions. Network, Bayesian phylogenetic and species delimitation analyses were performed to infer the number of taxonomic units and the phylogeographic relationships occurring within and among them. MANOVA revealed a significant dependence of the morphometry of hamuli and marginal hooks on host species and regions, but a clear differentiation between samples was not confirmed by PCA. Moreover, the ranges of all dimensions overlapped between samples. However, molecular analyses suggested the occurrence of at least two taxonomic entities. The most common entity was present in individuals of the Black and Mediterranean seas, and is described here as Gyrodactylus gerasevi n. sp., whereas a second entity recognized as a G. sphinx was found only in individuals from two localities off Crimea. The monophyletic cluster grouping of these two species was placed within a large clade that also included a separate sister cluster with seven other species of the Gyrodactylus orecchiae cross-ocean species group.

Amongst biological strains or races of the.stem eelworm, Anguillulina dipsaci, some are comparatively polyphagous and are capable of causing disease in a number of different host plants whilst others are restricted to one or two hosts. The strain causing “ tulip root” in oats is usually regarded as a restricted one being Confined to oats or, as in Yorkshire, to oats and beans, in which infection takes place in the seedling stage and persists during the greater part of the life of the plant. Whether the parasite will attack other agricultural plants is a matter of some practical importance and since in a crop rotation a seeds mixture for ley production may follow oats, it was decided to test whether the parasite would infect plants comprising a typical seeds mixture. It was also hoped to determine whether any of the grasses or clovers would be more or less permanently affected and thus serve as reservoir hosts for the parasite and so enable it to tide over the period between successive oat crops. The present paper deals with pot experiments set up to test this matter as a result of which it has been found that the oat strain of the parasite is capable of causing serious injury to the young seedlings of a number of grasses and clovers of a seeds mixture.

Brown and rainbow trout from Hanningf?eld Reservoir, Essex and rainbow trout from associated raceways were found to be infected with the metacercariae of Cotyluriis erraticus throughout 1968. Both o brown and rainbow trout of age 2+ introduced into the reservoir in the spring became heavily infected with C. erraticus during their first summer in the reservoir. Rainbow trout were more heavily infected than brown trout. Infection increased with age in rainbow trout but this was not apparent in brown trout. The metacercariae are almost completely restricted to the pericardial cavity of the trout. The life-cycle of C. erraticus in Hanningfield possibly involves gulls as final hosts and the gastropod Valvata piscinalis as first intermediate host. C. erraticus has probably been introduced into the reservoir in infected trout from outside sources, or by infected avian final hosts.

Six specimens of Xenopus laevis obtained from University College, London, were examined for polystomes; one harboured an adult worm measuring 2·1 mm. in length and two immature specimens, both 0·8 mm. in length, and one was parasitized by a single mature specimen measuring 2·4 mm. in length.

Inorganic substances play a significant role in the physiology of parasites and their importance, especially to gastro-intestinal parasites, is also demonstrated by the influence of mineral deficiencies in the host's diet (see Von Brand, 1966).

Groups of five 3-kg Kenyan monkeys, Cercopithecus aethiops, were exposed individually to 150,600 or 1500 Schistosoma mansoni cercariae per monkey. Three monkeys died soon after the infections became patent and the survivors were autopsied 4 months after exposure. Mortality and most haematological, parasitological and pathological sequelae of infection were dose-related, but not the white cell response or changes in the levels of serum proteins or fibrinogen. No gross liver fibrosis was seen. Comparison of this study with earlier ones on related cercopithecine monkeys suggests that the vervet closely resembles the baboon in its response to S. mansoni infections. Difficulties in managing and maintaining vervets can be overcome by using colonybred or properly adapted feral animals. Thus, the vervet provides a cheaper, more readily available primate model for experimental S. mansoni studies. A prolonged infection, sufficiently heavy to permit reliable parasitological monitoring without undue mortality, should be provided by 150 S. mansoni cercariae per kg body-weight, using the Kenyan strains of vervet and parasite.

Rudolphi (1819) first described a nematode from the intestine of Iguana tuberculata under the title, Ascaris megatyphlon. Since then considerable progress has been made in our knowledge of the parasitic Nematodes and most of the forms described by Rudolphi under Ascaris have been placed in new genera. Dujardin (1845) re-examined these forms and created a new genus, Ozolaimus, for Ascaris megatyphlon and removed certain other forms to the genus Oxyuris. He differentiated the two genera of Oxyuris and Ozolaimus by the presence of two simple lips in Ozolaimus and three simple or lobed lips in Oxyuris.

The free-living stages of Oswaldocruzia filiformis were cultured in tapwater under constant and changing temperature regimes. Embryonation and hatching proceeded at constant temperatures from 6° to 32°C; development of larvae to the third (infective) stage occurred between 6° and 34°C. The duration of development decreased with increased temperatures up to 28°C. The duration of development of egg and larval stages under changing temperatures was compared with values predicted from constant temperature experiments. The rate of development of eggs to hatching was significantly accelerated under regimes of both sudden and gradual temperature changes. The effect of fluctuating temperatures on larval development was less consistent; both acceleration and retardation effects were recorded. Frog tadpoles (Rana temporaria) were experimentally infected with O. filiformis; early parasitic development proceeded significantly faster at room temperature than at 9–10°C.

The identity of Anisakis type II larvae with adult A. physeteris was confirmed by comparison of restriction fragment length polymorphisms (RFLPs) of 25S ribosomal DNA (rDNA). Patterns of RFLPs in larvae were almost identical with those in adult worms. Directly labelled 25S rDNA might serve as an appropriate probe with highly specific activity for examining RFLPs of larvae and adult worms.

The present investigation has shown that combined treatment with dexamethasone and prednisolone or with hydrocortisone and dexamethasone enhances the susceptibility of albino rats to Paragonimus miyazakii, presumably by suppressing the host’s immune responses. In the rats given these combined treatments, the size and egg production of worms were markedly increased. Use of dexamethasone or prednisolone alone had relatively little influence on the growth and maturity of P. miyazakii. In serological analysis and agar double diffusion, considerable differences were recognized between the gamma-globulin fractions and antigen-antibody systems (Precipitin bands) of the treated groups and the untreated group. The mechanism of action of these immunosuppressants in this system remains obscure.

For the first time the development of the alimentary tract of Levinseniella brachysoma metacercaria (Trematoda: Microphallidae) obtained experimentally from Gammarus oceanicus has been described. The foregut primordium in 16-day-old metacercariae is represented by a syncytial cylindrical cord, resulting from the fusion of embryonic cells. Non-fused parts of the plasma membranes of adjacent cells are revealed as gap cavities within the cord. Later (30th day post infection) the lumen of the foregut is formed as a result of both partial vacuolization of the cytoplasm and by a broadening of the gap cavities, resulting from a thinning of the cytoplasmic spaces between them. Besides the usual organelles, the foregut of the mature metacercaria (42nd day p.i.) contains dense secretory granules in the apical cytoplasm region and numerous microtubules in basal areas. The cellular gastrodermis is formed later than the foregut syncytium (on day 30 p.i.); its large cells contain well-developed Golgi complexes, RER and mitochondria. A noteable inclusion of the gastrodermal cells of mature metacercariae are spherical granules of moderate electron density measuring up to 3 μm in diameter. On the basis of an analysis of the ultrastructural data the possible functioning of the metacercarial alimentary tract is discussed.

A new cestode, Paradilepis maieki sp.nov. is described from the intestine of a Sacred Ibis in the Sudan, and differentiated from the other nearer species.

Several females of this new species were collected by the writer from the stomach of the Nile fish, Gymnarchus niloticus Cuvier from Khartoum in the Sudan, on June, 1958. Three males and several females were collected from the same host and locality, by Dr. Hilmy Bishai of the Zoology Department, University of Khartoum on March, 1960 and forwarded to the writer.

We examined the associations between intestinal helminth infracommunity structure and infection parameters and the age, size, and year and region of collection of 130 female lesser scaup (Aythya affinis) during their 2014–2015 spring migrations through the upper Midwest, USA. We identified a total of 647,174 individual helminths from 40 taxa, including 20 trematodes, 14 cestodes, 4 nematodes and 2 acanthocephalans parasitizing lesser scaup within the study area. Lesser scaup were each infected with 2–23 helminth taxa. One digenean, Plenosoma minimum, is reported for the first time in lesser scaup and in the Midwest. Mean trematode abundance and total helminth abundance was significantly less in 2015 than 2014, and we suspect that colder weather late in 2015 impacted the intermediate host fauna and caused the observed differences. Brillouin's species diversity of helminths was greatest in the northernmost region of the study area, which coincides with the range of a non-indigenous snail that indirectly causes annual mortality events of lesser scaup. While host age and size were not determined to be influential factors of helminth infracommunity structure, non-parametric ordination and permutational analysis of co-variance revealed that year and region of collection explained differences in helminth infracommunities. Our results suggest that spatiotemporal variations play an important role in the structure of intestinal helminth infracommunities found in migrating lesser scaup hosts, and may therefore impact host ability to build endogenous reserves at certain stopover locations in the Midwest.