Nematoda of the genus Echinocephalus Molin, 1858 include species from the Gnathostomatidae family, the adult stages of which parasitize the stomach and spiral intestine of elasmobranchs as their final hosts. In the present study, we describe Echinocephalus spinosus n. sp. found parasitizing the spiral valve of the freshwater stingray Potamotrygon motoro from the Tapajós River, in the Amazon Basin, in the state of Pará, Brazil. In the study we performed morphological (light and scanning electron microscopy) and molecular (small subunit ribosomal ribonucleic acid (SSU rDNA) and mitochondrial cytochrome c oxidase I sequencing) analyses. E. spinosus n. sp. is only the second species of the Echinocephalus genus described from a strictly freshwater environment. The SSU rDNA based phylogenetic analyses showed Echinocephalus clade as a sister lineage of Gnathostoma, and that the new species arises as a sister to Echinocephalus cf. pseudouncinatus. Time-calibrated phylogenetic analysis revealed that the origin of the freshwater Echinocephalus coincides with the recently proposed origin of the freshwater host potamotrygonin stingray, namely the late Oligocene to early Miocene, when the western Amazon was dominated by the Pebas wetlands, an epicontinental marine/freshwater system.

Nematodes of the genus Gongylonema infect a wide range of mammals worldwide but are only sporadically reported in humans. We describe a case of human infection with Gongylonema pulchrum in a 41-year-old man. The patient extracted the nematode from the submucosa under his tongue and correctly self-diagnosed the infection with the help of the Google search engine. In the laboratory, the collected nematode was confirmed as G. pulchrum microscopically by morphological analysis and genetically by amplifying and sequencing the parasite's rDNA. This is the first report of human G. pulchrum infection in Slovenia.

Bunocotyle progenetica is a hemiuroid digenean whose sexual adults become fully developed and lay their eggs inside the rediae in the molluscan host. In this study, the fine structure of the germinal mass, brood cavity and birth canal in the B. progenetica rediae was examined using transmission electron and confocal microscopy. The large germinal mass attached to the body wall has a cellular composition typical for this organ. The characteristic traits of this germinal mass are weakly developed supporting tissue and the presence of deep lacunae opening into the brood cavity. These lacunae presumably participate in feeding the deeply lying embryos and facilitate their release into the brood cavity. The germinal mass is also characterized by intensive degeneration of cellular elements, which may represent a mechanism controlling the offspring number, limited in this species by the size of the redial brood cavity. The brood-cavity lining consists of flattened cells bearing lamellar projections and is connected anteriorly with the epithelium of the birth canal. The brood-cavity musculature, which is well developed in other hemiuroid digeneans, is significantly reduced in B. progenetica, most likely because their cystophorous cercariae remain inside the rediae, removing the need for muscle contractions pushing them through the brood cavity. The birth canal comprises three regions distinguished by the structure of the lining and muscle arrangement. The comparison of rediae of B. progenetica with parthenitae of other digeneans has shown that the organization of the redial reproductive apparatus in this species may have been influenced by life-cycle modification.

The life cycles of species of Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidea) parasitizing fishes in the Palearctic Region are reviewed on the basis of literary data and personal experimental observations, with special attention being paid to the development within the intermediate and definitive hosts. Planktonic crustaceans, diaptomid or cyclopid copepods (Copepoda), serve as the only intermediate hosts of all Proteocephalus species considered. A metacestode, or procercoid, develops in the body cavity of these planktonic crustaceans and the definitive host, a fish, becomes infected directly after consuming them. No previous reports of the parenteral location of metacestodes within the second intermediate host as it is in the Nearctic species P. ambloplitis have been recorded. Thus, the life cycles of Proteocephalus tapeworms resemble in their general patterns those of some pseudophyllidean cestodes such as Eubothrium or Bothriocephalus, differing from the latter in the presence of a floating eggs instead of possessing an operculate egg from which a ciliated, freely swimming larva, a coracidium, is liberated. The scolex of Proteocephalus is already formed at the stage of the procercoid within the copepod intermediate host; in this feature, proteocephalideans resemble caryophyllidean rather than pseudophyllidean cestodes. The morphology of procercoids of individual species is described with respect to the possibility of their differentiation and data on the spectrum of intermediate hosts are summarized. Procercoids of most taxa have a cercomer, which does not contain embryonic hooks in contrast to most pseudophyllidean cestodes. The role of invertebrates (alder-fly larvae — Megaloptera) and small prey fishes feeding upon plankton in the transmission of Proteocephalus tapeworms still remains unclear but these hosts are likely to occur in the life cycle. Data on the establishment of procercoids in definitive hosts, morphogenesis of tapeworms within fish hosts, and the length of the prepatent period are still scarce and new observations are needed. Whereas extensive information exists on the development of P. longicollis (syns. P. exiguus and P. neglectus), almost no data are available on the ontogeny of other taxa, in particular those occurring in brackish waters (P. gobiorum, P. tetrastomus). The morphology of P. cernuae and P. osculatus procercoids from experimentally infected intermediate hosts is described for the first time.

The effects of a diet deficient in the B vitamins on infectivity, growth, and distribution of Echinostoma caproni in ICR mice were studied. The vitamin-deficient diet (experimental) was isocaloric to the control diet but lacked the B vitamins. Thirty-six female, 6- to 8-week-old ICR mice were each infected with 25 metacercarial cysts. From the day of infection to the day of necropsy, 18 mice were fed the experimental diet and the remaining mice received the control diet. Equal numbers of experimental and control mice were necropsied at 2, 3 and 4 weeks postinfection (p.i.). Mice on the experimental diet showed a significant loss in body weight between 2 and 4 weeks p.i. There was no significant difference in worm recovery at 2 to 4 weeks p.i. from mice on either diet. Worms from hosts on the experimental diet were more dispersed and located more posteriad in the small intestine than those from mice on the control diet. Worm dry weight was significantly less in hosts on the experimental diet at all weeks p.i. compared with that of hosts on the control diet. The body area of worms on the experimental diet was significantly less at 2 and 3 weeks p.i. than that of worms on the control diet. An isocaloric diet deficient in the B vitamins had a detrimental effect on the growth of E. caproni in ICR mice.

The nematodes described below are in the collection of the Department of Parasitology, London School of Hygiene and Tropical Medicine and I am much indebted to Dr. R. T. Leiper, C.M.G., F.R.S., who allowed me to examine them and who gave me considerable help and encouragement throughout the work.

In a previous paper (1938) it was recorded that lemon-shaped cysts of the nematode Heterodera schachtii are frequently to be found in pasture soils. In many cases the soil has not, at least for a number of years, borne a crop such as oats or mangolds likely to have been infected with this nematode. The eelworm must therefore parasitize some plant or plants commonly to be found in pastures.

Protease activities in preparations from the plant-parasitic nematodes Heterodera glycines and Meloidogyneincognita and the free-living nematode Panagrellus redivivus were inhibited by exposure to a series of eight catechin polyphenol analogues, (+)-catechin, ( − )-epicatechin (EC), ( − )-gallocatechin (GC), ( − )-epigallocatechin (EGC), ( − )-catechin gallate (CG), ( − )-gallocatechin gallate (GCG), ( − )-epicatechin gallate (ECG) and ( − )-epigallocatechin gallate (EGCG) (1 mm each), and by a preparation from H. glycines cysts. General protease activity detected with the FRET-peptide substrate QXL520-KSAYMRF-K(5-FAM)a and proteasome chymotrypsin-like (CTL) activity detected with succinyl-LLVY-AMC were each inhibited significantly more (P< 0.05) by the gallated form of the polyphenol than by the corresponding non-gallated form. Species differences in response to inhibition across all analogues were revealed with the CTL substrate, but CG was a consistently potent inhibitor across all three species and with each substrate. A heat-stable component (CE) from H. glycines cysts inhibited M. incognita CTL activity by 92.07 ± 0.68%, significantly less (P< 0.05) in H. glycines (52.86 ± 2.77%), and by only 17.24 ± 0.55% (P< 0.05) in P. redivivus preparations. CTL activity was, however, inhibited more than 60% in all preparations by the proteasome-specific inhibitor MG-132. Hatching of M. incognita infective juveniles exposed to 1 mm CG, ECG, GCG or EGCG was reduced by 83.88 ± 4.26%, 69.98 ± 9.14%, 94.93 ± 1.71% and 87.93 ± 2.89%, respectively, while hatching of H. glycines was reduced less than 25% by each analogue. CE had no effect on nematode hatch, but did cause a 60% reduction in mobility of H. glycines infective juveniles exposed overnight to CE in vitro, which was more (P< 0.05) than the reduction of M. incognita infective juvenile mobility (20%).

Paradistomoidella cerberi n.g, n.sp. and Paracanthostomum cerberi from Cerberus rhynchops, Xenopharynx pyriformis and Allopharynx mehrai from Ptyas korros, Neopronocephalus orientalis from Geoemyda spinosa, and Duthiersia expansa from Varanus salvator are all reported from the area of Kuala Lumpur, Malaysia. Paradistomoidella cerberi most closely resembles members of Paradistomum and of Paradistomoides but is characterized by relatively short caeca, a cirrus sac containing a bipartite rather than sinuous internal seminal vesicle, and unevenly-sized suckers. Kuala Lumpur is a new locality for Paracanthostomum cerberi, X. pyriformis, A. melvrai, and D. expansa. Ptyas korros is a new host for X. pyriformis and G. spinosa is a new host for N. orientalis.

Several methods are being applied for solubilizing adult Schistosoma mansoni antigens which may allow their immunochemical characterization and purification. Studies on antigens and immunoprecipitins in schistosome infections have been carried out with homogenized extracts of adult worms and/or larval forms of Schistosoma mansoni in saline (Biguet et al., 1962; Kagan and Norman, 1963; Silva and Ferri, 1965), or water (Kent, 1963). Kusel (1972) studied surface proteins in S. mansoni membrane, treating the worms with 0·5% saponin in 3% calcium chloride. Murrel et al. (1974) compared by immunodiffusion a crude culture antigen with extracts obtained by freeze-thawing of adult worms and by treatment in 3M KCl.

The outer cysts (Oc) of Fasciola gigantica metacercariae (Mc) were separated in an aqueous two-phase system composed of polyethylene glycol and dextran in distilled water. A large number of separated Mc without Oc were recovered in the bottom layer rich in dextran in the system. Ten separated Mc in the layer were used to inoculate the mouse with a syringe and juveniles were recovered from the animals on the 14th day. When the number of juveniles recovered was compared with that from the mice infected orally with the same number of Mc, there was a significant difference between them (P <0.05). The former method is easier than the latter for inoculation.

Since Fasciola sp. contained proteolytic enzyme(s), it was confirmed that degradation took place in protein components in extracts of the liver flukes, which resulted in lack of clarity of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Degradation was shown to occur mostly during a heating process of the extract samples. The proteolytic activity in the extracts was completely blocked and electrophoretic patterns were improved only by the use of cysteine proteinase inhibitor N-[N-(L-3-trans-carboxyoxiran-2-carbonyl)-L-leucyl]-agmatine (E-64). Great improvement was also noted in electrophoretic patterns of the extracts of other trematodes, such as Paragonimus westermani, P. miyazakii and Clonorchis sinensis, when their extracts were treated with E-64.

Third-stage and fourth-stage Dirofilaria immitis larvae exhibited positive thermotaxis when placed in a thermal gradient. Negative thermotaxis was not observed. Positive thermotaxis may be important for the successful transmission and for directing third and fourth-stage larval migration toward predilection sites in the Host.

Taliaferro and Sarles (1939) who studied the cellular reaction in the skin, lung and intestine of normal and immune rats after infection with N.muris, stated that “larvae were found penetrating the skin from a half hour through two hours after they had been placed on the skin. They seemed to penetrate directly…” Yokogawa (1922) observed that this parasite when placed on the skin of rats, penetrated into the tissues very quickly. He did not specify any time for their entrance.

Echinostephilla virgula occupies an isolated position in the Digenea; apparently it does not belong with certainty to any of the existing families and, as the original description is incomplete, it was considered worthy of re-description. This trematode was found frequently at St. Andrews between the months of September, 19–19, and March, 1951, in the intestine of the Turnstone (Arenaria interpres Linn.). There was usually a heavy parasitism, fifty to one hundred worms being found in one host. However, in spite of frequent examinations of birds shot after this period, no further specimens were found.

The question of the immunity of the pig to ascariasis has been considered by helminthologists for some years and is still a vexed question. Ransom (1922) was of the opinion that the pig became immune at the age of 4 months but this was refuted by Morgan of the Institute of Agricultural Parasitology who, in 1931 successfully infected pigs at the age of 10 months and by the present writer (1934) at the age of a year. Sandground in 1929 referred to the difficulty of establishing infections under normal conditions though it is well known that almost every pig under field conditions picks up an infection at an early age. Furthermore, it is notoriously difficult to keep pigs “clean” for experimentation though this can be done, as it is done here, by careful attention to detail during rearing.

It is only within the last few years that the various species of Bulbous Irises have been recognised as host of Anguillulina dipsaci. Despite the comparative paucity of information on the matter there is evidence of the likelihood of infestations becoming serious in the immediate future. It may, therefore, be of value to place on record such information as is at present available.

Experimental infection of larval Echinococcus multilocularis in the rodent brain was attempted to establish a murine model for cerebral alveolar echinococcosis. Balb/c mice and jirds were injected intracranially with 10% of a homogenated hydatid cyst mass. Small cystic larvae were observed macroscopically in the cranial cavity 1, 2 and 5 months post-infection in both mice and jirds. Some larval cysts from both rodents contained mature or immature protoscoleces. In mice, the laminated layer was found in the lateral ventricle 2 months post-infection but without protoscoleces. At five months post-infection, larger larval cysts were found in the cranial cavity of a mouse, which also demonstrated partial palsy of the legs. A laminated layer with mature protoscoleces was observed in the third ventricle and the mouse also harboured, in the left lung, a larval cyst containing protoscoleces surrounded by lymphocytes. Jirds were also found to be infected with metacestodes in the cranial cavity, but neither unusual behaviour nor establishment of cysts inside the brain was observed in jirds during the course of infection.

In 1956 the author described five new species of Procamallanus from India and also gave an amended key to the species, originally described by Annereaux (1946). Meanwhile a few more species were reported from India and elsewhere, but as the author had no access to the publications, these species were not included in the key. To clarify certain points the following review is given.