A survey of nematodes associated with terrestrial slugs was conducted in residential gardens, nurseries, greenhouses and agricultural sites located in and around Edmonton, Alberta, Canada. A total of 2406 slugs were collected from 82 sites. Slugs were decapitated and cadavers were incubated for two weeks, with emerging nematodes removed and processed for identification. Nematodes were identified using molecular sequence data for the 18S ribosomal DNA. Nematodes were recovered from 20 of the 82 sites surveyed, with 24.4% of the slugs infected with nematodes. A total of seven nematodes were identified to species level, including Caenorhabditis elegans, Panagrolaimus papillosus, Pellioditis typica, Pelodera pseudoteres, Rhabditella axei, Rhabditoides inermiformis and Phasmarhabditis californica. An additional four specimens were identified to genus level, including Oscheius sp. (9), Pristionchus sp., Rhabditis sp. and Rhabditophanes sp. (1). The two most common nematode species were C. elegans and P. pseudoteres. The facultative parasite, P. californica, was recovered from a single Arion rufus specimen, collected from a seasonal nursery. To our knowledge, this study represents the first survey of slug-associated nematodes in Canada.

Pallisentis (Pallisentis) nandai Sarkar, 1953 is a freshwater fish parasite restricted to the Indian subcontinent in the Ganga River and its tributaries. It was described from the leaffish, Nandus nandus (Hamilton) from the Ganga River delta at Calcutta. We recovered variant specimens from the same host species from the Ganga near its headwaters at Bijnor about 1500 km away. Our specimens were clearly identifiable as P. nandai but varied considerably from those in the original description, especially in the size of proboscis hooks, receptacle and lemnisci. The original description was incomplete (missing line drawings of female trunk and reproductive system, male trunk, complete proboscis, hooks and hook roots) and inaccurate (proboscis, hooks, receptacle wall), and some measurements were lumped together for both sexes. We provide a complete description and include new morphological information including the first description of para-receptacle structure in the genus Pallisentis Van Cleave, 1928, scanning electron microscopy and microscope images, molecular analysis, and energy dispersive X-ray analysis (EDXA) of hooks and spines of our specimens for the first time. Additional details of proboscis hook roots, trunk spines, micropores and micropore distribution are described. The unique metal composition of hooks (EDXA) demonstrated a considerably high but variable level of sulphur and negligible level of calcium in collar and trunk spines and hook tips, but a higher level of sulphur and calcium at the hook basal arch than at the hook tip and edge. A comparison with the EDXA pattern of another species of Pallisentis, P. İndica Mital & Lal, 1976, were considerably different. The phylogenetic position of P. nandai within Eoacanthocephala was generated to assess the molecular characterization based on 18S and ITS1-5.8S-ITS2 ribosomal DNA sequences. Maximum likelihood and Bayesian inference analyses placed P. nandai in a clade with other Pallisentis species under the family Quadrigyridae. This is the first report based on molecular evidence for P. nandai.

Tests have been made with methyl bromide to investigate its efficiency in destroying infective stages of some helminth and protozoan parasites of poultry and game birds. It appears to have an immediate strong lethal action against ova of the common nematode parasites and against oocysts of Eimeria tenella. Its efficiency against ova of Choanotaenia infundibulum was not definitely proved. When used in the field, it penetrates soil to a depth of several inches, and in so doing destroys both ova and many invertebrates known to be vectors of poultry parasites. Land which has been treated remained quite free from parasitic infection for many months but gradually became re-infested. Wild birds were probably the agents for they carry ova accidentally on their feet and in the gut.

Ovine and equine protoscoleces of Echinococcus granulosus were cultured for 26 days with our without praziquantel and viability assessed, by eosin exclusion, for cultures in various drug concentrations (50, 250 and 500 μg/l) and periods of exposure (1, 3 or 7 days (d)) before removing/‘rescuing’ to drug-free medium. Drug efficacy was proportional to drug concentration and to length of exposure. At higher drug concentrations shorter exposures were required to produce the effect of continuous drug treatment, 1d therapy at 500 μg/l killing 96% ovine protoscoleces by day 14 whereas 7d therapy at 50 μg/l was required to produce a similar effect. Equine protoscoleces appeared marginally less susceptible than those of ovine origin. The relevance of the results in the need for peri-operative prophylaxis against spilled protoscoleces in man is discussed.

An in vivo study in the laboratory rat model has been carried out to monitor changes to the spermatogenic cells in the testis tubules of adult Fasciola hepatica following treatment with the artemisinins, artemether and artesunate. Rats infected with the triclabendazole (TCBZ)-resistant Sligo isolate were dosed orally with artemether at a concentration of 200 mg/kg and flukes recovered at 24, 48 and 72 h post treatment (pt). Rats infected with the TCBZ-resistant Oberon isolate were dosed orally with artesunate at a concentration of 200 mg/kg and flukes recovered 24, 48, 72 and 96 h pt. The flukes were processed for histological and transmission electron microscope (TEM) examination. Changes to the spermatogenic cells were evident at 24 h pt with artemether. The spermatogonial and spermatocyte cells contained abnormal mitochondria, there were fewer spermatids and spermatozoa in the tubules than normal, and a number of cells showed signs of apoptosis. There was a further decline in cell numbers at 48 h pt and the organization of the spermatocyte and spermatid rosettes was atypical. Sperm formation had become abnormal and those spermatozoa present possessed only a single axoneme. By 72 h pt, the testis tubules were vacuolated and filled with abnormal cells and cell debris. Only spermatogonial cells could be identified and there was widespread evidence of apoptosis in the cells. Distinct cellular changes following artesunate treatment did not become apparent until 48 h pt. The changes seen were similar to those described for artemether, but were generally less severe at matching time-periods. The fine structural changes occurring in the spermatogenic cells were compared to those observed in other cell types and fluke tissues and the overall information was collated to identify the cellular targets for artemisinin action and to establish the time-line for drug action.

The following observations cover the second half of a year's survey of the helminthic parasites of domestic animals in the Aberystwyth area from the beginning of April to the end of September, 1924. The results obtained during the first six months of the survey were published in this Journal in April, 1924 (Vol. II. No. 2).

Bulinus (Physopsts) africanus antigens were shown to be associated with the cercarial glycocalyx of Schistosoma haematobium using immunofluorescence and the Cercarienhüllen Reaktion. It is proposed that this snail antigen may sensitise the definitive host and that resistance to further invasion by cercariae could be induced in this manner.

Onchocerca raillieti sp. n. (Filarioidea), from the domestic donkey (Equus asinus) in Africa, is described. The species is compared to O. bohmi (Supperer, 1953) n.comb, O. reticulata Diesing, 1841, O. cervicalis Railliet et Henry, 1910, O. flexuosa (Wed), 1856) and O. armillata Railliet et Henry, 1909 and can be differentiated by numerous characters of which the most important are the anterior region of the female (which is straight and slender, 6 to 8 cm long, and bears longitudinal striae) and the 10 symmetrically arranged pairs of caudal papillae. O. raillieti seems to be a primitive species by several characters (caudal papillae, cervical papillae, oesophagus, vulva and cuticle.)

The presence of naturally occurring entomopathogenic nematodes (epns) was surveyed in the West-Flanders province in the north-west of Belgium. In 21 sites of different agronomical situations, 130 soil samples were taken. Using the Galleria larva bait technique, 16 soil samples were found positive for epns. Fifteen samples were found to contain Steinernema spp. (nine S.feltiae, five S. affinis, one Steinemema species B3). The remaining positive sample contained Heterorhabditis sp. (North West European strain). The morphometric characters of the isolates were highly variable and did not correspond precisely to the original descriptions; however, biochemical characterization confirmed their identity. The epns were isolated from 50%, 18.8% or 12.3% of the samples taken in sand dunes, grassland or woodlands, respectively. S. feltiae and S. affinis were isolated in these three habitats; Heterorhabditis sp. was found in a grassland habitat. Steinernema feltiae was prevalent in loamy sand soils with a wide range of organic matter content; S. affinis, Heterorhabditis sp. and Steinernema species B3 were isolated in sandy loam soils. All the positive sample sites were in the pH range of 4.0–8.1. This is the first report of naturally occurring entomopathogenic nematodes in Belgium.

The ultrastructure of the reproductive system of adult male Trichinella spiralis has been examined, particularly to assist in recent advances such as the localization of target antigens of protective immunity and the mode of immune attack. The male reproductive system consists of a single tube with a hairpin-like bend, composed of a basal lamina, epithelial cells, rachis, circumferential and constrictor muscles, and germinal cells. The organs were surrounded by basal lamina and haemolymph. Germinal cells in different stages of maturation were found on the wall of the testis along its entire length. As the maturation of germinal cells proceeded, the cells moved towards the lumen of the testis. The germinal cells had a row of vesicles (cup-shaped structures) at the cell periphery. The mature sperm, lacking flagella and an acrosome, were stored in the seminal vesicle. The cytoplasm of the epithelial cells of the seminal vesicle and ejaculatory duct was filled with distended rough endoplasmic reticulum (rER) and exocrine granules which appeared homogenous and of medium electron density. The granules appeared to discharge to the lumen.

Experiments are described in which calves were given 200 metacercariae and then a challenge infection of 300 metacercariae. When the challenge infection was given 3 weeks after the initial infection a small but insignificant reduction in take was observed. When the challenge infection followed 18 weeks after the initial infection, the existing infection was eliminated. This phenomenon is referred to as an “acquired self cure”.

The causes of the beaching and death of sea turtles have not been fully clarified and continue to be studied. Mild, moderate and severe lesions caused by spirorchiidiosis have been seen for decades in different organs and were recently defined as the cause of death of a loggerhead turtle. In the present study, eyes and optic nerves were analysed in green sea turtles with spirorchiidiosis and no other debilitating factors. Injuries to the optic nerve and choroid layer were described in 235 animals (90%) infected with spirorchiids. Turtles with ocular spirorchiidiosis are approximately three times more likely to be cachectic than turtles with spirorchiidiosis without ocular involvement.

The potato tuber moth, Phthorimaea operculella (Zeller), is a serious pest of potato and other commercial crops belonging to the Solanaceae family. In recent years, it has become an emerging problem in potato-growing regions of the Nilgiri hills of southern India. It is responsible for the reduced quality and quantity of marketable potatoes. In this regard, the development of an eco-friendly control method for the management of the potato tuber moth is urgently required. Therefore, in the present study, the virulence of Steinernema cholashanense CPRSUS01 originally isolated from the potato rhizosphere was tested on fourth-instar larvae and pupae of P. operculella. Steinernema cholashanense caused the greatest mortality in the fourth-instar larval stage (100%) than the pupae (30%). In addition to this, penetration and reproduction of this nematode was also studied in fourth-instar larvae of P. operculella and this is the first report of penetration and reproduction of any entomopathogenic nematode species on potato tuber moth larvae. The reproduction capacity of S. cholashanense on P. operculella is higher (702 infective juveniles mg−1 body weight). Our results indicated that S. cholashanense has good potential as an alternative tool for the management of P. operculella. But before including S. cholashanense in the integrated pest management program of P. operculella, its efficacy should be tested under field conditions.

Previously uninfected eleven month old sheep were used as indicators of the availability of the infective larvae of sheep nematodes in early spring. Ostertagia and Nematodirus species were acquired in much larger numbers than other species. It is concluded, since the order of parasitism found in the experimental sheep resembled that found in spring born flock lambs in early life, that the relative specific incidence is the latter is due to the numbers of available infective larvae and not to any factor associated with the stage of development of the lambs.

There are many recorded cases of parasites that are capable of altering the behaviour of their host to enhance their transmission efficiency. However, not all of these cases are necessarily the results of the parasites actively manipulating host behaviour; they may rather be the ‘by-products’ of pathology caused by the parasite's presence. This study investigates the effect of the microphallid trematode Maritrema novaezealandensis on the behaviour of one of its crustacean intermediate hosts, the amphipod Paracalliope novizealandiae. Uninfected amphipods were experimentally infected by exposure to M. novaezealandensis cercariae. The activity level and vertical position of experimentally infected amphipods were compared with uninfected amphipods at 2 weeks and 6 weeks post-infection, i.e. both before and after the parasite achieved infectivity to its definitive host. Infected amphipods were found to exhibit significantly lower levels of activity and to occur significantly lower in the water column than uninfected controls during both periods. Based on the timing of the change in behaviour exhibited by infected amphipods, the results suggest that the altered behaviour exhibited by P. novizealandiae infected with M. novaezealandensis is most likely due to pathology caused by the parasite rather than a case of active, and adaptive, behavioural manipulation.

We amplified the cDNA coding for arginine kinase (AK) from the parasitic nematode Ascaris suum, cloned it in pMAL plasmid and expressed the enzyme as a fusion protein with the maltose-binding protein. The whole cDNA was 1260 bp, encoding 400 amino acids, and the recombinant protein had a molecular mass of 45,341 Da. Ascaris suum recombinant AK showed significant activity and strong affinity for the substrate l-arginine. It also exhibited high catalytic efficiency comparable with AKs from other organisms. Sequence analysis revealed high amino acid sequence identity between A. suum AK and other nematode AKs, all of which cluster in a phylogenetic tree. However, comparison of gene structures showed that A. suum AK gene intron/exon organization is quite distinct from that of other nematode AKs. Phosphagen kinases (PKs) from certain parasites have been shown to be potential novel drug targets or tools for detection of infection. The characterization of A. suum AK will be useful in the development of strategies for control not only of A. suum but also of related species infecting humans.

The species of the Nematode genus Strongyloides are of considerable interest to helminthologists and extensive studies on the biology of their life-history have been carried out by various workers. Their chief interest lies in the fact that the parasitic stage consists of hermaphroditic forms only, while in the free-living stage there may be a differentiation into males and females before reaching the infective stage. This alternation in the life-cycle is also exhibited by the allied genus Rhabdias, with the exception that, according to Railliet (1899) and Goodey (1922), certain species from the snake do not appear to have this differentiation in the free-living stage.

Redescriptions of the cercaria, metacercaria and adults of N. triserialis and N. imbricatus are given. Cercariae developed in Lymnaea peregra and Bithynia tentaculata respectively and infected snails were collected from the Wentloog level, near Cardiff, South Wales. The characters adopted by Dubois for distinguishing species of this genus are more reliable than any alternative and the number of ventral glands is considered to be a reliable diagnostic feature in spite of suggestions to the contrary. The possibility of using chemical differences between the metacercarial cysts and other stages as a means of speciation is discussed.

A brief description of Nematodirus battus has been given elsewhere (Crofton and Thomas, 1951), but this included only sufficient details for specific diagnosis. A more detailed account is given below.

The worms are long, slender and more or less straight. The cuticle is smooth except in the cephalic region where it is inflated and is lightly striated. The cephalic inflation extends 0.12 mm. from the anterior end and is 0.06 mm. in diameter (see Fig. 1). In some specimens the cephalic inflation may be reduced and relatively inconspicuous. Although this variation may be due to fixation, it occurs in members of a batch which have been fixed simultaneously. The head is 0.03 mm. in diameter and bears six papillae round the mouth. The “mouth capsule” is small and bears a tooth on the dorsal side. This tooth is not easily visible in Fig. 1 because of contraction of the oesophagus. (The term mouth capsule is retained because it has been used by other workers (see Rajewskaja, 1918, Travassos, 1987) but if the definitions of Baylis and Daubney (1926) are adopted it would be more correct to refer to the tooth as lying in an oesophageal funnel). The oesophagus is relatively short, 0.35–0.54 mm. in length.

The only account of the larval stages of Bunostomum trigonocephalum (Rud.) which I have been able to find is a brief note by Baillet (1866), in which he states that the larvæ of Uncinaria cernua Crep. = B. trigonocephalum (Rud.), develop in water and hatch within four or six days. The newly hatched larvæ are “rhabditiform,” .35 to .4 mm. long and ·23 to .3 mm. broad, and the tail is very thin and filiform.