Infected hosts progressively decrease egg output during the chronic phase of Schistosoma mansoni infection. Ageing may be a factor that results in a progressive decrease in the ability to reproduce. This study was performed to gain insight into the effects of ageing on adult schistosomes, using confocal laser scanning microscopy. Adult worms were recovered from experimentally infected Nectomys squamipes (water rat). Viable eggs were voided in the faeces for 65 weeks and, thereafter, only unviable eggs were eliminated. The rat died after 70 weeks in captivity. Recovered worms (six males and one female) were prepared for confocal microscopy and images were obtained with an LSM 510–ZETA laser confocal microscope. The overall morphology of the adult worms (suckers and tegument) and reproductive organs were the focus of this work. The suckers, ovary, vitellaria and oocytes appeared to be apparently normal. The ootype was formed by flattened cells and unclear nuclei, suggesting that the mechanism for eggshell production by the ootype during organogenesis might have been impaired. Testicular lobes showed empty areas around the germinative cells. Male adult worms showed flaccid musculature of the dorsal surface. Taken together, the present results provided several indications of infertility in older male and female schistosomes.

Neoechinorhynchus is one of the most speciose genera of acanthocephalans, with approximately 116 described species. A recent study, aimed at establishing the genetic diversity of Neoechinorhynchus in Middle American freshwater fishes, validated nine species molecularly and morphologically and revealed the existence of 10 putative candidate species. Neoechinorhynchus golvani, a parasite commonly found in cichlids throughout Middle America with an allegedly large intraspecific morphological variability, was found to represent a species complex; species delimitation methods uncovered three additional genetic lineages. Here, we re-analyse the morphological and molecular data for N. golvani species complex infecting cichlids in that geographical area. A multivariate analysis of variance (MANOVA) was conducted particularly for the length of apical, middle and posterior hooks of the species/lineages of Neoechinorhynchus in cichlids, revealing morphological variation in the length of apical hooks for Lineage 8, although no morphological distinction was observed for Lineages 9 and 10. A new concatenated phylogenetic analysis of one mitochondrial and two ribosomal DNA genes was used to further corroborate the species delimitation among lineages; Neoechinorhynchus Lineage 8 was found to be morphologically and genetically distinct from its sister taxa, N. golvani and other two undescribed genetic lineages, and is formally described as a new species. Neoechinorhynchus costarricense n. sp. is described from the intestines of eight species of cichlids in Costa Rica. The new species is distinguished from the other species/lineages of Neoechinorhynchus in cichlids mainly by the size of the apical hooks of the proboscis.

1. The gastro-intestinal tracts of 200 mink from 42 farms were examined for helminth parasites.

2. No parasites were found in the stomach but two species of fish-borne parasite were found in the intestine.

3. Evidence of infestation with the heterophyid trematode Cryptocotyle lingua was found in twelve mink, the largest number of flukes recovered from any one mink being seven.

4. Single immature specimens of the acanthocephalid Corynosonta hadweni were recovered from four mink, but it is considered that these were not instances of true parasitism.

5. It is concluded that helminth parasites do not constitute an important hazard on mink farms in Britain;

Yeh Liang-Sheng and Fotedar (1958) reviewed the genus Astiotrema Looss, 1900 and considered A. reniferum, A. impletum, A. odhneri and A. monticelli as the only valid species of the genus. They transferred A. emydis Esjmont, 1930 to Leptophallus Lühe, 1909 without giving any reason. However, recently Grabda-Kazubska (1961) has rightly revalidated A. emydis. Since the revision of the genus by Yeh Liang-Sheng and Fotedar (1958), three more species have been added. They are A. geomydia Siddiqui, 1958, A.sudanensis Khalil, 1959, and A. trituri Grabda, 1959.

Recent collection of lung fluke material from hydrophiid sea snakes permits a reevaluation of the suitability of criteria separating the monotypic genera Pulmovermis Coil and Kuntz, 1960 and Hydrophitrema Sandars, 1960. Consideration is also given of the new subfamily Pulmoverminae, erected by Sandars (1961) to include these genera within the digenetic family Hemiuridae. Typographical errors in the original description of H. gigantica Sandars, 1960 have been corrected, reducing the gross or external measurements of that species by ten times. Validity of characters such as flexure of the body, location of testes and ovary with respect to body length, length of seminal vesicle compared to body length, and anterior extension of the seminal vesicle with respect to acetabulum have been rejected. Retained are general body shape, relative position of acetabulum and development of peduncle, degree of coiling of seminal vesicle, and tandem or oblique arrangement of testes. Characters newly employed include body length-to-width ratio and presence of a cuticular fold in Hydrophitrema enclosing both suckers. Retention of the present genera based on these revised characterizations is recommended. Subfamily criteria (form, structure, and size of seminal vesicle, shape of vitellaria) are similar to those employed among the other nineteen subfamilies of this large and possibly heterogeneous group. In addition, these flukes are unique within the family on ecological and physiological grounds, in that they parasitize the lungs of sea snakes rather than the stomach of marine fishes, the usual site and host for members of this family.

In the Pampa region of Argentina, farming activities have been performed since the beginning of the 20th century, but in the 1990s, land-use patterns rapidly changed towards intensive agriculture and poultry breeding. This study compares the helminth community of Akodon azarae (Rodentia) among three habitats with different land use in pampean agroecosystems: poultry farms, mono-cultivated fields and abandoned fields (not used for 35 years), under the prediction that there will be greater helminth richness and diversity in mice from abandoned fields compared to those from the other habitats. Nevertheless, the highest abundance of A. azarae occurred on poultry farms, the habitat most disturbed by human activity, while cultivated fields showed the lowest. Helminth richness and diversity were significantly higher on poultry farms than in the other habitats, due to the presence of Trichuris laevitestis, Protospirura numidica criceticola and cysts of Taenia taeniaeformis. We suggest that the helminth fauna of A. azarae can survive on poultry farms despite disturbance from farming activities, because rodents can move and get shelter within farm perimeter fences, where dense and high vegetation grows. This farm area could offer good conditions for geohelminth development, while chicken sheds could attract insects that are intermediate hosts of helminths with indirect life cycles. On the contrary, agrochemicals applied in cultivated fields would negatively influence helminth diversity and composition, by decreasing host populations (arthropods and rodents) and affecting free larval stages of geohelminths.

Furcocercariae of the genus Neodiplostomum Railliet, 1919 (Diplostomidae Poirier, 1886) were found in freshwater snails Helicorbis sujfunensis Starobogatov, 1957 (Planorbidae Rafinesque, 1815) collected from three localities in the Russian southern Far East. For the trematodes from each locality, frogs played the role of the second intermediate host, and rats were the definitive host. Chickens were insusceptible to infection. The morphological and molecular data obtained for these trematodes indicated they were representatives of the same species. The experimentally-derived adult individuals were morphometrically similar to the East Asian Neodiplostomum seoulense (Seo, Rim, Lee, 1964), Neodiplostomum oriolinum Oschmarin, 1963, Neodiplostomum leei Chai and Shin, 2002, and Neodiplostomum boryongense Shin et al., 2008. Analysis of available data on the life cycle, developmental stage morphology, and molecular genetic characteristics of East Asian Neodiplostomum revealed a lack of information for objective assessment of the species status of neodiplostomula found in the East Asia region. Based on the considerations above and the data for the cox1 marker, we named the trematode Neodiplostomum cf. seoulense (Seo, Rim, Lee, 1964) sensu Pyo et al., 2014. In a phylogenetic reconstruction based on nuclear and mitochondrial markers, neodiplostomulas clustered into geographically related groups: South American, North American, European, and East Asian, with the former occupying an external position in the tree, which may indicate South America as a center of Neodiplostomum speciation.

The superfamily Pronocephaloidea Looss, 1899 comprises digeneans occurring in the gut and respiratory organs of fishes, turtles, marine iguanas, birds and mammals. Although many life cycles are known for species of the Notocotylidae Lühe, 1909 maturing in birds and mammals, relatively few are known for the remaining pronocephaloid lineages. We report the cercariae of five pronocephaloid species from marine gastropods of the Queensland coast, Australia. From Lizard Island, northern Great Barrier Reef, we report three cercariae, two from Rhinoclavis vertagus (Cerithiidae) and one from Nassarius coronatus (Nassariidae). From Moreton Bay, southern Queensland, an additional two cercariae are reported from two genotypes of the gastropod worm shell Thylacodes sp. (Vermetidae). Phylogenetic analysis using 28S rRNA gene sequences shows all five species are nested within the Pronocephaloidea, but not matching or particularly close to any previously sequenced taxon. In combination, phylogenetic and ecological evidence suggests that most of these species will prove to be pronocephalids parasitic in marine turtles. The Vermetidae is a new host family for the Pronocephaloidea.

It is well known that the first two larval stages in the life cycle of nematodes belonging to the superfamily Strongloidea, have a freeliving existence. During this time, the larva which hatches from the egg feeds actively, undergoes two moults and grows considerably before reaching the infective stage, when it is ready to invade a definitive host. Under natural conditions this external development takes place in the faeces, which have been deposited by the infected host on ground likely to be contaminated with various bacteria.

Neodiplostomum (Conodiplostomum) ramachandrani sp. n. is described from Rattus muelleri in Kepong, Selangor, Malaysia. It is characterised by having symmetrical dumbell-shaped testes, and vitellaria as a single ventral band in the hindbody. The taxonomic relations ofNeodiplostomum, Conodiplostomum and Fibricola are discussed and possible significance of the fluke as an ecological indicator noted.

It was shown that maintenance of cercariae of S. mansoni and S. haematobium at low (10°C) and high temperatures (40°C) markedly increased their mortality during penetration of mammalian host skin. These increased losses in the skin accounted for the known decrease in infectivity, as measured by adult worm recovery, of cercariae kept at low or high temperatures.

5 males and 5 females of this species were collected from the intestine of the giant African rat Cricelomys gambianus from Minaki Secondary School, near Pugu, Tanzania. Some of the specimens have parts of the host's intestinal wall tissues in their buccal capsules and some specimens have the anterior part of the intestine dark in colour. This may suggest that these nematodes attach themselves to their host's intestinal wall and probably feed on its blood.

The elongated body is cylindrical, tapering at both ends, the anterior end recurved dorsally. The cuticle is transversely striated and the buccal aperture is round, lacking a radial crown but the cuticle of the external surface of the buccal capsule forms several annular thickenings around the buccal aperture. There are 4 main external cuticular bands extending to near the buccal aperture. The buccal capsule is funnel-shaped with extremely thick and highly chitinized walls, the dorsal wall notably shorter than the ventral. The thickness of the walls is uneven, with maximum thickness posteriorly. The capsule lacks teeth and the dorsal oesophageal gland terminates near the anterior edge of the buccal capsule. The oesophageal funnel is chitinized. The oesophagus is claviform owith a wider posterior part and ends in a triradiate valve.

Twenty-eight adult specimens of 2 new species, Aphelcnchoides appendurus and A. montanus, were collected from the rhizoids of moss adhering to the bark of pine trees in the Mussoorie Hills, at an altitude of 7,500 feet above sea level, in Uttar Pradesh, India.

The 2 new species, which belong to the “parietinus” group of the genus Aphelenchoides Fischer, 1894, are described and illustrated.

During the summer of 1961 an opportunity arose which enabled us to study the incidence of certain helminth parasites in pigs slaughtered at Roath Abattoir, Cardiff. The studies were undertaken primarily because of the apparent lack of incidence figures concerning the helminth parasites in pigs from the southern part of the Principality. Some information was available for other regions of the Principality as Morgan (1924), Jones (1926) and Lewis (1930) have published reports on helminth parasites of pigs from Central and North Wales. Unfortunately none of these papers provided any comparative data on incidence of the various helminths, the numbers of each species in each infection and the proportion of sexes for each helminth in a given population.

1. Ten species of Capillaria are recorded from eight species of British birds. C. blomei from the pheasant and partridge and C. exilis from the rook are new host records.

2. The identity of C. reseda and the systematics of C. blotnei, C. bursata and C. caudinflata are discussed in the light of observations made upon material in the collection.

The influence of nonspecific immunomodulation on the course of experimental infection was examined in larval cestodosis (Mesocestoides corti) and ascaridosis (Ascaris suum) in mice. Immunosuppressive treatment (with azathioprine or hydrocortisone) resulted in a decrease of resistance in both models. The subsequent administration of T-activin to immunosuppressed mice led to the restoration of resistance to a level equal to that of untreated control mice. The administration of different immunomodulators partially protected mice against M. corti (T-activin. thymomodulin) or A. suum (T-activin. thymomodulin. thymosin fr.5. bursa-activin) infection. The protective effect of different treatments did not correlate with the level of specific antibody in the sera of infected mice. These results, which confirmed the decisive role of T-cell immunity in the resistance to the helminth infections, raise the possibility of the use of immunomodulators (thymic preparations) in the immunoprophylaxis of helminthoses.

The results obtained in the tests described above are summarized in the following table :—

Matricaria matricarioides (Less.) Porter, self-sown in one of the inoculated pots, is an addition to the known weed hosts of narcissus races of D. dipsaci and a new host record for the species.

Seinhorst (1952) has emphasized the need for caution in interpreting the results of host tests with D. dipsaci. Exposure to heavy infestations will often result in invasion and local necrosis of the tissues of plants which are not true hosts of the race concerned. Seedlings may easily be killed outright in this way. The present tests lead to similar conclusions as shown, for example, by the results obtained with red clover and oat seedlings. Even deposition of eggs in the tissues cannot be taken as evidence that the eelworms have established themselves. It is considered, however, that a plant may be regarded as a true host when it is clear that the eelworms are breeding freely in the tissues, i.e. when eelworms in all stages of development are present with numerous eggs, and when infestation is able to persist during the normal life of the plant. With bulbous plants, the establishment of an infestation in the new bulbs after the leaves and flowers had died down was taken as evidence that the plant was a true host. The typical effects of D. dipsaci on the tissues of its hosts, e.g. hypertrophy of parenchyma tissues, enlargement and loosening of the cells and dry, mealy rotting, are also useful criteria, but some of these effects may be produced occasionally after invasion of non-hosts, as was found in a few of the inoculated clover seedlings.

A further modification of a lung perfusion technique was evaluated by examining the recovery rate of 14-day-old Dictyocaulus viviparus worms from the excised lungs of 15 dead bovine calves. Up to 89% of the total number of worms found in 12 l of perfused fluid was recovered in the first 4 l collected. The application of this observation will increase the efficiency of the routine laboratory diagnosis of D. viviparus infection.