Oligapla manteri sp. nov. is described from the gills of Hernirham phus sp. from Noumea, New Caledonia. It differs from the existing species in the genus, O. oligapta because the atrial spines are res tricted to a circle of 16, the penis is armed with 47 anteriorly directed, pear-like spines, and the sclerotization of the copulation canal is conical. Pseudothoracocotyle scomberomori sp. nov. is described from the gills of Scornberomorus commersoni from Heron Island, and Green Island, Queensland, Australia. The new species differs from the existing species in the genus, P. ovalis, because the genital pore is not sclerotized, there are two pores to the copulation canal, and the clamps are more numerous and larger.

I should like to thank Dr. H. W. Manter of the Department of Zoology, University of Nebraska who very kindly gave me the specimens of Oligapta manteri; Dr. W. W. Becklund of Beltsville Parasitological Laboratory, U.S.A. who kindly lent me cotypes of T. crocea, and Dr. J. C. Pearson of the Department of Parasitology, University of Queensland for his help during the study.

RECENT investigations carried out by the senior writer on the incidence of parasitic helminths in the alimentary tract of sheep in the north of Scotland have demonstrated heavy losses in lambs due to parasitic gastritis. In the autumn of 1932 six severe outbreaks were recorded in the counties of Kincardine, Aberdeen and Moray, but no doubt this number would have been greatly exceeded had it been possible to make a comprehensive survey. Some idea of the severity of the disease may be judged by the fact that several farmers lost from 10–20 per cent, of their lambs.

During 1928 I was able, as Milner Research Fellow in the Department of Helminthology of the London School of Hygiene and Tropical Medicine, to make an extended survey of the parasites of man and the domestic animals in the British West Indies. A report on the former has already been published (1929). In examining the parasites of domestic animals, I was given every facility by the local authorities, and I am especially indebted to Captain H. V. Metivier, B.Sc., M.R.C.V.S., of Trinidad, whose assistance and knowledge of the local parasitic problems was invaluable.

(1) During the routine examination of the fauna of samples of clinker removed from the filter beds of Brent Sewage Farm several species of Rhabdilis were met with, one at least of which cannot be relegated to any species as yet described. A new species is therefore suggested for its reception and the name succaris has been given to suggest its origin from the sewage farm.

(2) An account is given of its structure. While being typical for the genus, the lips and bursal rays do not agree with any known species.

(3) Two distinct strains were reared by means of different culture media, differing quite definitely in length. A thousand worms were measured and these differences were found to remain very constant. The relative measurements have not been materially altered.

(4) The length of the large worms has been diminished by means of a return to the original food.

(5) The cultivated strain shows greater variability than the original strain.

(6) Two graphs and a table summarising the results are shown.

Studies on the symptomatology of red-ring disease were carried out by the author (Goberdhan; 1961) on thirty-two trees at La Forest Estate. It was hoped that from this study, methods for detecting the disease at an early stage would have been developed. If this were possible, then therapeutic treatment might be administered to combat the disease and so save a tree from destruction. From these field observations, it appeared unlikely that very early infection could be detected visually, since infection in the stem was found to be well advanced even when only one or more leaves showed signs of rich, gold, yellowing, typical of the disease. The initial time of infection could not be determined nor could the length of time elapsing between infection and the onset of symptons. It was therefore decided to artificially infect young, and apparently healthy palms, to estimate rate of spread of infection, the length of time from infection to appearance of symptoms, and the possible detection of very early infection.

Studies conducted in the 1980s suggested that parasites were useful in distinguishing adjacent populations of Atlantic cod Gadus morhua in the north-western Atlantic. During the mid-1980s, cod populations began to decline, culminating in closure of the fishery in 1992. A marked decrease of cod off the coast of Labrador was coincident with climatic shifts, including a decline of bottom sea temperature, and virtual absence of capelin Mallotus villosus, its main food prey. These changes in some components of the ecosystem were independent of anthropogenic influences. An initial survey of cod parasites in 2000 from coastal Labrador revealed a dramatic decline in abundance of metazoans and also a change in dominance of species of digenetic trematodes compared to 1980–1981. Comparison of metazoan parasites in three other populations of cod inhabiting the Grand (northern and southern) and St. Pierre Banks, where there was no apparent evidence of environmental changes but only commercial over-exploitation, revealed no major alterations in abundance or dominance between 1980–1981 and 2003. The results of this current study suggest that environmental changes in the food web affected the abundance of metazoan parasites only off coastal Labrador but did not influence the use of the parasites to distinguish between cod populations inhabiting the Grand or St. Pierre Banks.

One male specimen was collected from the liver of a short tailed wallaby, Macropus brachyurus, which died in the Zoological Gardens, London on 26th September 1960. It is a slender worm 82 mm. in length and 0·41 mm. in maximum width. The anterior extremity is rounded. There is a small buccal cavity and at the base of this there is a prominent cuticularised ring. The cephalic end bears four pairs of submedian papillae and a pair of amphids. The en face view was not studied because of the lack of specimens. The cuticle is transversely striated all over the body and there are bosses like small slightly curved markings on it.

This study compares the morphology, anatomy, physiology and histochemical distribution of two key enzymes (AcPase and ATPase) in the intestinal trematode Ganeo tigrinum recovered from hibernating and non-hibernating Rana cyanophlyctis and R. tigrina. It has been shown that the torpid state of the host influences its worm so severely that it produces untanned and low quality eggs, the sperm population falls, the rate of worm infection is decreased and the worms do not grow.

AcPase has been shown to undergo significant changes during hibernation, especially in the gut, where extraordinarily high activity seems to be responsible for the autophagy of certain gastrodermal cells. ATPase similarly reveals a decrease in activity in most of the parasite tissues during hibernation. However, its high activity in the parenchyma has been related to the quick transportation of metabolites, representing the threshold concentration necessary for survival and egg production.

Proteases in the soluble fraction of homogenates prepared from the free-living nematode Panagrellus redivivus hydrolysed the amidated invertebrate neuropeptides FMRFa and FLRFa, and nematode FMRFa-like peptides (FLPs) KPNFLRFa (FLP-1-H), APKPKFIRFa (FLP-5-A), KNEFIRFa (FLP-8), KPSFVRFa (FLP-9), RNKFEFIRFa (FLP-12) and KHEYLRFa (FLP-14) in vitro. Results were assessed by analysing reaction components with RP-HPLC, UV detection at 210 nm and peak integration. Based upon substrate peak size, more than 90% of most of the peptide substrates was consumed after 1 h at 27°C, but digestion was not complete even with a crude protease mixture. Two peptides, FLP-12 and FLP-14, were significantly less susceptible to digestion than the others. FLP-12 was the least susceptible of all sequences (71% loss; P < 0.0001), while FLP-14 was digested less (84% loss; P < 0.0004) than all but FLP-12. Product peak digestion patterns of FLP-12, a second nonapeptide (FLP-5-A), and FMRFa, incubated with aminopeptidase (amastatin) and serine endoprotease (AEBSF) inhibitors, demonstrated highly specific behaviours of each sequence to protease cleavage. Amastatin significantly (P < 0.03) reduced digestion of FLP-12 (54% loss) and FMRFa (61% loss; P < 0.0005), but had no effect on FLP-5-A. AEBSF had no protective effect on FMRFa but significantly decreased hydrolysis of FLP-5-A (77% loss; P < 0.0001) and FLP-12 (59% loss; P < 0.03). The combination of both inhibitors had additive effects only for FMRFa (34% loss; P < 0.0005). Further analysis of FMRFa digestion using peptides with d-amino acid substitutions demonstrated nearly complete protection of FdMRFa (2% loss; P < 0.0001) from all proteolytic digestion, whereas digestion of FMRdFa was complete. Results suggest that in addition to aminopeptidase and serine proteases, both deamidase and aminopeptidase P participate in neuropeptide metabolism in P. redivivus.

During the course of studies on human filariasis in Fiji in the period 1954–50, two new microfilariae were found in fruit bats. The first was found in the blood of 38 bats out of 111 examined from various islands of the territory. It has recently been described and named Microfilaria fijiensis by Yeh, Symes and Mataika (1958).

The paper describes findings of three species of nematodes of the genus Oxyspirura parasites of birds in Czechoslovakia: O. (S.) petrowi (Skrjabin, 1929) from Lanius collurio L., O. (S.) rysavyi Baruŝ, 1963 from Oriolus oriolus oriolus and O. (O.) chabaudi n.sp. from Motacilla alba alba L.

The head region of 72 bullet tuna Auxis rochei from the western Mediterranean Sea (south-east Spain and the Strait of Gibraltar) was examined for parasites. Seven metazoan species were found in the fish from south-east Spain: three monogeneans, two trematodes and two copepods, whereas only three species were isolated in the fish from the Strait of Gibraltar. A comparison of the levels of infection of the parasites according to fish size in south-east Spain showed that the prevalence of Didymozoon auxis and the mean abundance of Allopseudaxine macrova were higher in the larger hosts (range of fork length = 38–44 cm) than in the smaller ones (33–37 cm). A comparison of the parasite infections according to geographical region showed that the mean abundances of Nematobothriinae gen. sp. and Caligus bonito were higher in fish from south-east Spain than in those from the Strait of Gibraltar. A comparison of the parasite fauna of A. rochei from the Mediterranean Sea with the published data on Auxis spp. from the Atlantic, Indian and Pacific Oceans revealed the closest similarity between the Mediterranean A. rochei and the Atlantic A. thazard.

A new monogenean fluke, collected from the urinary bladder of a megophryid frog, Xenophrys glandulosa Fei, Ye & Huang, 1991 from Mokokchung and Tuensang districts of Nagaland, north-eastern India is described. Of the six genera under the subfamily Polystomatinae (Polystomatidae) known so far, the present form comes closer to Eupolystoma Kaw, 1950; Pseudopolystoma Yamaguti, 1963 and Riojatrema Lamothe-Argumedo, 1964, in all of which the opisthaptor lacks large hooks. However, a combination of characters, namely, shape of the body, rounded or bulbous pharynx, intestinal caeca not joining posteriorly in the opisthaptoral region, ovary located in the anterior third of the body and presence of vaginal apertures, sets the present form apart from all these genera, and also from the known species of Riojatrema. These differences warrant the establishment of a new species and a new genus to accommodate the present form. The validity of this new monogenean, named as Neoriojatrema mokokchungensis after the type locality of the fluke, is discussed.

This new species is a rare parasite of the freshwater fish Clarias lazera Cuvier and Valenciennes. Twenty-four fishes from the White Nile and the Blue Nile from Khartoum area in the Sudan were examined from October, 1957 to May, 1958. Only five fishes, all from the White Nile, were found to harbour this new species and each fish contained not more than two worms.

The prevalence of schistosomiasis and the distribution of the snail intermediate hosts on three adjoining irrigated estates in the lowveld of Swaziland was investigated. The prevalence rates of Schistosoma haematobium and S. mansoni among estate employees was lower than anticipated and there was a marked difference between the prevalence rates of S. mansoni between estates. The reasons for this and the influence of water supplies and agricultural practice on the prevalence of schistosomiasis are discussed.

An annotated checklist of the helminth parasites associated with reptiles from Peru is provided, as the result of a compilation of parasitological papers published between 1963 and January 2022 and records of species deposited in national and international collections. The list provides data on hosts, developmental stage, sites of infection, geographical distribution in Peruvian territory, code of material deposited in helminthological collections, references and taxonomic notes. The database includes records of 106 different species of helminth parasites (82 nominal species and 24 taxa identified at the generic level), the majority in the adult stage. These helminth parasites come from 18 of the 25 official Peruvian regions. Nematodes have the highest richness in number of species (79 species), followed by trematodes (17 species) and cestodes (nine species). The acanthocephalans are represented by only one species. The parasites with the highest number of records were Physaloptera retusa Rudolphi, 1819 (11 hosts), Physalopteroides venancioi (Lent, Freitas & Proença, 1946) (nine hosts), Strongyluris oscari Travassos, 1923 (seven hosts), and Parapharyngodon scleratus Travassos, 1923 (five hosts), all of which are nematodes. The 106 taxa of helminth parasites have been reported infecting 55 species of reptiles in Peru, distributed in 34 genera and 14 families. The reptile species harbouring the highest number of helminth parasites are the yellow-footed tortoise Chelonoidis denticulatus (Linnaeus) with 18 species (three trematodes and 15 nematodes), followed by the Peru desert tegu Dicrodon guttulatum Duméril & Bibron (Teiidae) with 11 species (three cestodes and eight nematodes) and the yellow-spotted Amazon River turtle Podocnemis unifilis Troschel (Podocnemididae) with 10 species (five trematodes and five nematodes). Of the 524 species of reptiles reported in Peru, only 55 (>10%) are reported as hosts of helminths representing a small proportion considering the great variety of reptile hosts that inhabit the various tropical and subtropical geographical areas of Peru.

Rabbits were experimentally infected with two levels (5000 and 17000) infective larvae of Nematodirus spathiger. Histological (villus length, mucosa to serosa ratio, crypt surface) and biochemical (protein content, alkaline phosphatase and leucine aminopeptidase activities) measurements relating to the small intestinal mucosa were examined along the entire length of the organ. In the proximal intestine, the presence of worms was associated with villus abrasion, increased crypt surface and decreased alkaline phosphatase and leucine aminopeptidase activities. Conversely, beyond the main Site of infection in the distal small intestine, some signs of hypertrophied villi and crypts were noted without any changes in enzyme activities. These distal variations were similar to those previously described in experimental Trichostrongylus colubriformis infections of rabbits. These results tend to confirm the use of the rabbit as an experimental model to study Nematodirus infection. They also suggest that the distal adaptive process in the nematode-parasitized small intestine could occur independently of the worm species.

The effect of dietary cobalt from three different sources on uninfected and Ascaridia galli-infected Hisex chickens, has been studied. The chicken diet was supplemented with 0.06 Co2+ kg-1 food either in the form of two glycine–cobalt compounds or mixed zinc–cobalt basic salt. An excess of dietary cobalt in small doses increases the gain of body weight and decreases host mortality. A greater bioefficiency of cobalt was established in infected chickens. A mathematical model has been used to provide a quantitative interpretation of the observed results. The model solutions of the kinetics of worm numbers and body weight are in a good agreement with experimental data. The model is valid for different degrees of A. galli infections and for treatment with different trace elements. The value of the kinetic parameter, regarded as a phenomenological constant of the host immune response, depends on the degree of infection.

The effects of interferon (IFN) γ on the course of infection with Strongyloides papillosus in calves were investigated. Calves (N=7 each) were inoculated with recombinant bovine IFNγ or control solution daily from day 0 to day 15 following S. papillosus infection. Treatment with IFNγ induced an increase in faecal egg output in the peak stage of infection. The IFNγ-treated animals harboured more worms, especially more immature worms, in the small intestine than control animals at necropsy on day 17, with no decreases in intestinal mucosal mast cells. Both animal groups had similar small numbers of intestinal worms at necropsy on day 26. All control animals developed peripheral blood eosinophilia on day 7, while five of seven IFNγ-treated animals did not. Serum α1-acid glycoprotein concentrations increased on day 7 in both animal groups, with higher values in control animals than in IFNγ-treated animals. Control animals mounted a predominant IgG1 response to S. papillosus from day 10, while IFNγ-treated animals did from day 22. These data suggested that IFNγ inhibited some host protective responses to S. papillosus migrating larvae, resulting in an improvement of worm survival after a period when protective responses should be activated during the early stage of infection. The effects of IFNγ on intestinal worm expulsion should be confirmed by further experiments.