This paper reports the occurrence of Skrjabinema ovis and Trichostrongylus spp. not previously identified in sheep and goats in Iran. A complete list of the helminth parasites now known to exist in sheep and goats in Iran is included in the discussion.

The genus Pharyngostrongylus was proposed by Yorke and Maplestone, 1926, for some strongyle nematodes from Macropus sp., which they named P. macropodis. Later in the same year, Mönnig described another new strongyle nematode Spirostrongylus australis from Macropus rufus, erecting a new genus for it. The generic name of Mönnig's species was changed to Rugopharynx Mönnig, 1927, the first being pre-occupied (Spirostrongylus Yorke and Maplestone, 1926). In 1929, Wood gave a description of some specimens collected from Macropus woodwardi which were identified as Rugopharynx australis Mönnig. Wood also pointed out that “the presence of a buccal capsule, a corona radiata, and a fairly large and differentiated dorsal lobe to the bursa copulatrix seem to exclude it from the Trichostrongylidae where Mönnig has placed it and he considers that it belongs to Trichoneminae.” Furthermore, he transferred that species to the genus Pharyngostrongylus on the basis of “the arrangement of its buccal capsule and its markedly ringed pharynx” considering Rugopharynx a synonym of Pharyngostrongylus.

The erythrokinetics of three baboons were studied over a twelve week period after infection with 3 000 cercariae of S. mansoni and compared with three uninfected control animals. In addition to monitoring changes in haematological and parasitological parameters several radioisotopic techniques were used concurrently to measure alterations in red cell kinetics. In particular 51Cr-labelled red cells and 59Fe-ferric citrate were used to measure red cell production, circulating volume, survival time and routes of loss.

All the animals remained in good condition despite heavy infection and the pathophysiological changes were in general mild and transient in nature. The principle alterations were associated with patency and consisted of a modest fall in haematocrit, some inappetence and the appearance of blood-stained mucus in the faeces. Red cell survival was reduced in the infected animals and this was correlated with an increase in faecal blood loss and haemodilution. There was no evidence of haemolytic factors or depressed erythropoiesis having any aetiological role in the anaemia.

The results confirmed the complexities of schistosomal anaemia as well as the ability of primates to withstand heavy parasitic burdens for short periods with minimal pathophysiological disturbance.

The isoenzymatic pattern of glutamate dehydrogenase (GDH) has been described for Ascaris suum, a parasite of Sus scrofa domestica. Only one band of activity has been revealed, suggesting a monomorphic condition for this enzyme. Also, the structure of GDH has been assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS–PAGE) and silver staining. Only one subunit was present with a molecular weight of about 55 000. A hexameric structure for GDH of A. suum is suggested.

1. A new species Choanotaenia larimarina sp.nov. from the greater black-backed gull (Larus marinus) is described.

2. A comparison is made with other species of Choanotaenia which possess a reticulate uterus.

3. Because the uterus breaks down in only one of these four species it is suggested that in this type of development the breakage may be due to mechanical stretching of the tubule in the gravid segment.

4.If this be true then the portion of the uterine wall which envelops the egg is not a uterine capsule in the accepted sense.

Albino mice were infected per os with 1000 infective larvae of Ancylostoma caninum and pulmonary superoxide dismutase activity was studied after completion of lung migration. The total superoxide dismutase activity per mg of lung protein was elevated by 15% in infected mice. Of the two forms of superoxide dismutases studied, that containing Cu-Zn was elevated by 44%. this suggests that A. caninum in mice may result in histopathological changes leading to transient pulmonary oxygen toxicity.

A new echinostome fluke Pameileenia gambiensis gen. et sp. nov. is described from a water snake Grayia tholloni from Gambia. A note on the distribution of the host is included since this is the first record of it from the Senegambia region.

Specific and non-specific esterases have been localized in sections and whole mounts of Avitellina lahorea, an intestinal parasite of sheep and goats. Non-specific esterases (NSE) were found in the sucker muscles, post-acetabular ganglia, nerve trunks, tegument, excretory canals, cirrus sac, vagina, uterus and the inner membrane of the embryophore. Acetylcholinesterase (AChE) was observed in all the above organs, including vas deferens and sperm ducts, but was absent from excretory canals and eggs. Tests with acetylthiocholine iodide (AThChI) revealed the nervous system, vas deferens, sperm ducts, uterus, cirrus sac and the vagina. The intensity of activity of AChE and AThChI was weak compared to NSE.

This paper forms a preliminary account of the occurrence of some helminths parasitic in sheep and pigs in South-Eastern England. The rocks of the Wye district are mainly Cretaceous, while Romney Marsh, with its extensive sheep population, is alluvial. Earlier workers have already considered certain helminthic parasites of this region. The present writer uses Morgan's technique. Thirteen helminths parasitic in the gut of sheep and lambs are listed with notes, and a record is made of some other observations, including the identification of Ascaris lumbricoides and Œsophagostomum dentatum from swine.

The redia, cercaria and metacercaria of Opisthodiscus nigrivasis from Ancylastrum fluviatilis are described. Observations were made on the behaviour of the cercaria and experimental infections with metacercariae have been carried out in laboratory-raised frogs of the species Rana ridibunda. Some features of the morphology of these juvenile stages and aspects of the behaviour of the cercaria are compared with those of others related species.

The best known biological cycles in the Diplodiscinae are those of Diplodiscus subclavatus (Pallas, 1970) Diesing, 1836, and Megalodiscus temperatus (Stafford, 1905) Hanvood, 1932. The first was described by Looss (1892), who showed that the molluscs Planorbis nitidus, Pl. vortex, Pl. rotundatus, Pl. spirorbis and Pl. contortus acted as intermediate hosts. More recently Milka (1970) found young forms of D. subclavatus in Pl. planorbis and gave a brief description of the redia and cercaria of this species.

An account is given of observations on the occurrence of nematodes of the genus Meloidogyne in the Gold Coast. It includes a list of seventy-six host plants, both cultivated and wild, suitable for the sustenance and multiplication of the parasites as well as comments on the reactions of these various plant species to invasions of their root tissues. Many of the host plants listed constitute new records and the data submitted point to the conclusion that the root-knot eelworm has been long established in the Gold Coast.

Two strains of laboratory white mice, CFLP and LACA, were infected with the metacestodes of Taenia crassiceps. The serum from each infected mouse was tested for antibodies on double-diffusion gel plates and the number of antigen-antibody precipitin lines formed related (a) to the duration of the infection and (b) to the volume of metacestodes. There was a significant increase in the number of antigen-antibody precipitins with regard to the time infected but not to the volume of metacestodes. The pattern of development of the antigen-antibody precipitation system was also examined.

Plasma etching and ashing for demonstrating the three-dimensional ultrastructure of the internal organs of helminths is described. Adult worms of the cestode Caryophyllaeides fennica were dehydrated through an ethanol series, critical point dried (Polaron E3000) and sputter coated with 60% gold-palladium (Polaron E5100) and glued to a standard scanning electron microscope (SEM) stub positioned as required for ashing. After initial SEM viewing of worm surfaces for orientation, stubs were placed individually in the reactor chamber of a PT7150 plasma etching and ashing machine. Worms were exposed to a radio frequency (RF) potential in a low pressure (0.2 mbar) oxygen atmosphere at room temperature. The oxidation process was controlled by varying the times of exposure to the RF potential between 2 to 30 min, depending on the depth of surface tissue to be removed to expose target organs or tissues. After each exposure the oxidized layer was blown from the surface with compressed air, the specimen sputter-coated, and viewed by SEM. The procedure was repeated as necessary, to progressively expose successive layers. Fine details of organs, cells within, and cell contents were revealed. Ashing has the advantage of providing three dimensional images of the arrangement of organs that are impossible to visualize by any other procedure, for example facilitating testes counts in cestodes. Both freshly-fixed and long-term stored helminths can be ashed. Ashing times to obtain the desired results were determined by trial so that some duplicate material was needed.

Slugs are important agricultural pests causing yearly yield losses. However, parasitizing helminths potentially could affect the size of the slug population. Here, a survey of terrestrial slug-parasitic helminths (nematodes and trematodes) was conducted for the first time in Sweden. In total, 268 terrestrial slugs were collected from 27 agricultural field edges in three seasons over 2020 and 2021 and dissected for presence of helminth parasites. Slugs belonging to the genus Arion were molecularly identified by mitochondrial DNA cytochrome c oxidase subunit I (COI) while parasites were identified using ribosomal RNA (18S). Overall, 13% of the collected slugs had helminth parasites and the likelihood of a slug being parasitized was highest in autumn. Slugs identified as Arion vulgaris were more likely to be parasitized than native slug species. The prevalence of nematodes and trematodes were similar; the dominant species found were Alloionema appendiculatum and Brachylaima thompsoni, respectively. This is the first record of the presence of these two species in Sweden.

The in vivo efficacy of monensin against Fasciola hepatica was determined in the albino rat. The results were variable, with monensin generally showing greater activity against juvenile (two-week-old) than adult (12-week-old) fludes. Significant (p<0·005) reductions in worm burdens were obtained only following treatment of adult flukes with 2×10 mg/kg monensin (52·9% efficacy), and of juvenile flukes with 1×10 mg/kg (42·4% efficacy) and 2×10 mg/kg (56·23% efficacy). Monensin administered in the diet (200 ppm) had a negligible effect on juvenile and adult fluke burdens. Prophylactic treatment of rats with monensin (100 ppm) produced a 45·5% efficacy, but this was not statistically significant. At doses of 1×5 mg/kg and 2×2·5 mg/kg, monensin had little effect on egg output by F. hepatica. No clear relationship was established between egg output and worm burden, and so faecal egg counting was not a reliable indicator of fluke burdens in the rat.

The cuticle is finely striated and is partially reflected over the lips. The cervical papillae are symmetrically placed and occupy a position just anterior to the junction of the two parts of the oesophagus at about the same level as the nerve ring, some 0·32 mm. from the anterior end. The pseudolips are hemispherical and lateral. Each of the two pseudolips carries two papillae, one towards the latero-dorsal border and one towards the latero-ventral border. An amphid is situated centrally between the two papillae on each pseudolip. Internal to the pseudolips there is a complete denticular crest comprising externo-lateral teeth, interno-lateral teeth, paired submedian teeth and intervening denticles (Fig. 1). The externo-lateral teeth are large and pointed; the interno-lateral teeth, somewhat more posteriorly placed (Fig. 2), are smaller and also pointed. The four pairs of sub-median teeth are easily distinguished by their greater size from the denticles. The four spaces between the sub-median teeth and the externo-lateral teeth are each occupied by six to seven denticles. These denticles are larger in size than the very small denticles of which ten occupy the dorsal and ten occupy the ventral angles of the denticular crest.

Different groups of mice were infected with various single or repeated doses of larvae of Ancylostoma caninum. Considerable loss of larvae occurred in the immunised groups when compared with their counterpart unimmunised groups. Larval migration and distribution in the different tissues was less in immunised mice, as most larvae were expelled from the gastrointestinal tract. This resulted in a poor onward larval migration to liver, lungs, brain and muscle regions in immunised groups. The heavily immunised group infected five times was most affected and a significant lesser larval distribution in various organs and muscle region observed.

A new species, Hymenolepis miniopteri is described. The specimens studied were recovered from the ileum of the bat, Miniopterus blepotis (Temminck, 1840) from South Queensland.

The type and cotype specimens are lodged in the Queensland Museum, Brisbane, Australia.

The effects of crowding on growth, reproduction, rate of recovery and site of infection of Philophthalmus nocturnus were investigated by infecting various groups of day-old chicks with 25, 50,75, or 100 excysted metacercariae and examining them at 10 or 25 days post-infection. Considerable reduction in the body length and the size of the gonads was noticed in flukes grown under crowded conditions. Crowding also caused some change in the habitat of flukes, but had no effect on their rate of recovery. Very few flukes reached the ovigerous stage under overcrowded conditions and none reached the embryonated larval stage.