A description and the molecular characterization of two new species in the Haploporidae and Haplosplanchnidae families are provided herein. Parasaccocoelium armatum n. sp. was collected from the intestine of a Mugil cephalus Linnaeus, 1758 from the Primorsky region, Russia, and Pseudohaplosplanchnus catbaensis n. g. n. sp. was collected from Moolgarda seheli (Forsskål, 1775) in the coastal waters of Cat Ba Island, Vietnam. The morphological features of P. armatum n. sp. closely resemble those of Parasaccocoelium polyovum, but these species differ from one another by hermaphroditic sac and vitellaria area length and by maximal egg size. The main difference between P. armatum n. sp. and P. polyovum is the presence of an armed hermaphroditic duct in the new species. Molecular data support the case for inclusion of the studied trematodes in P. armatum n. sp. Worms P. catbaensis n. g. n. sp. from the mullet from Vietnam are morphologically close to Haplosplanchnus (Haplosplosplanchninae). The only difference between P. catbaensis n. g. n. sp. and species of Haplosplanchnus is the presence of few (1–7) large eggs, measuring 135–142 × 92–104 μm, versus numerous small eggs with a maximal size of 75 × 50 μm. Phylogenetic analysis showed that there is a contradiction between the morphological similarity of the worms and their position in the Haplosplanchnidae system, based on the genetic data. Results of this study indicate that P. catbaensis n. g. n. sp. is genetically distant from other representatives of Haplosplanchnus, despite their morphological similarity. According to the molecular data, P. catbaensis n. g. n. sp. is close to Hymenocotta mulli Manter, 1961 (Hymenocottinae). However, these species are considerably different to each other morphologically. Molecular data argue for the possibility of establishing a new subfamily for P. catbaensis n. g. n. sp. However, considering earlier studies of Haplosplanchnidae, we support the view that creating new subfamilies within this family is unreasonable because of the lack of molecular data for most haplosplanchnid species, which are necessary to resolve the problematic systematics and phylogeny of this family.

Metacestodes of Taenia crassiceps were cultured in laboratory rats and mice, washed in glycine/hydrochloric acid (Gly/Hcl) buffer pH 2·4 and phosphate buffered saline (PBS) pH 7·2 and a soluble extract of the metacestodes (SEM) was prepared from larvae washed in both buffers. The SEM and the original washings were examined for host IgG and a common host antigen (CHA). CHA was present in both the SEM and Washings but IgG only in the washings and, in metacestodes from mice only in the Gly/HCl washings). Metacestodes washed in Gly/HCl were not viable.

Metacestodes were also maintained in vitro in a peptide nutrient agar and 0·9% saline at 37°C and a SEM was prepared from these; metacestodes from mice had neither host IgG nor CHA but those from rats had CHA but not IgG. SEM prepared from ‘normal’ metacestodes showed that the CHA consisted of at least two entities, only one having a common identity with the IgG. These results suggest that molecules of both host IgG and a common host antigen are present on the tegument of these parasites.

A number of these nematodes were sent to this Department for identification early in 1958 by Dr. J. F. B. Edeson from the Institute for Medical Research at Kuala Lumpur. The specimens were collected from the peritoneal cavity of Macaca irus. Since then, several further collections of the same species have been sent to this Department from time to time. The latter collections came from several laboratories using monkeys caught in Malaya and Siam for the production of poliomyelitis vaccines.

Pelecitus galli n.sp. is described from the Malayan jungle fowl Gallus gallus spadiceus. It differs from other species of the genus in the size of the spicules, number and arrangement of caudal papillae in the male, and the relative position of the vulva. It is also the first species of Pelecitus described from the genus Gallus.

Three types of microfilariae were seen in blood and lung smears of two jungle fowls trapped in Tasek Bera in Pahang State. One of these microfilariae is indisguishable from that described by Dissanaike (1963) from the Ceylon jungle fowl. One of the other two resembles the microfilaria of Pelecitus ceylonensis described from Ceylon (Dissanaike, 1967) and adults were found between the tendons at the bases of the legs of one of the jungle fowls examined.

Because of the negative binomial distribution of filarial third stage larvae (L3) in their vectors, under natural conditions only a few are usually transferred per bite. After an inoculation of 5 L3 per animal into eight host animals at least one developed a long lasting patency based on one reproductive female only. After an inoculation of 15 L3, three of eight animals developed long lasting patency, harbouring between two and five fertile females. The rates of adult stages recovered were 0·43 and 0·30 respectively. The parasitaemias of the six patent animals in both experimental groups increased with the number of reproductive females present (r=0·89, p=<0·005). All non-patent animals which were mf-negative in the pleural fluid and lung blood as well had a single sex or no worm load. In only one animal was there an apparently normal but non-reproductive pair of worms without any pathological alterations of the host animal. Encapsulated adult worms were found rarely, but independent of the final worm load or inoculation dose and always beside normal adults. In three of the 16 animals inoculated with 5 or 15 L3 patency passed after 10–12 weeks p.i., in two others it seemed to pass soon. After inoculation of 30, 40 or 60 L3 per animal patency passed early in about one half of 105 animals, when they were observed up to 24–36 weeks p.i. In conclusion all types of host defensive reactions are already visible after inoculation with such small doses. Nevertheless even a single inoculation of 5 L3 may give rise to a patent animal and its microfilaraemia is sufficient for transmission under natural conditions. Higher inoculation doses increase the defensive reactions which nevertheless remain unable to destroy all invasive stages.

In their preliminary paper (Fenwick and Franklin, 1942) on the identification of the cyst-forming species of the nematode Heterodera by means of the length of the larvae, the present authors studied methods of preparing the larvae for measurement and of making the measurements, and considered the form of sample to be taken from a population of Heterodera larvae which would give the most reliable estimate of the mean length of the whole population. Those studies were made on the larvae of H. rostochiensis only, but the ultimate purpose was to obtain strictly comparable estimates of the mean lengths of the larvae of all the known species of Heterodera in order to find out whether larvae of the different species could be identified by their length.

1. When potatoes are planted in eelworm infested land, the root diffusate produced results in 70—80 per cent, of the larvae emerging from the cysts in the first 4—5 weeks of growth and this effect is shown up to a distance of 6 in. from the root centre.

2. Moderate or heavy soil infestations of potato root eelworm result in a considerable root invasion prior to potatoes breaking through; several thousand cysts can result from this early attack and can cause severe dislocation of the young root.

No article involving the nematode cuticle can ignore the work of Donald Lee. Since the publication of his book Physiology of nematodes (Lee, 1965), he has provided us with an extensive knowledge of the structure, composition, maintenance and growth of a variety of nematode cuticles and has undoubtedly contributed a great deal to our understanding of this unique and diverse structure.

A total of 687 adult nematomorphs of four species of Gordiida: Chordodes brasiliensis (393 specimens), Noteochorododes cymatium (47 specimens), N. talensis (162 specimens) and Pseudochordodes dugesi (85 specimens) were collected during a period of 1 year from El Simbolar stream, Argentina. Free-living worms were abundant during autumn and spring, but their number decreased during winter and summer. Males were shorter and significantly more abundant than females. The presence of N. cymatium, N. talensis and P. dugesi was correlated with water temperature and these species were most abundant in winter and spring. The presence of C. brasiliensis was correlated with flow rate and pH; this species was more abundant in autumn and winter. These four species are sympatric.

This study used Balb/c mice to examine the longevity of Echinostoma caproni. Five mice each exposed to 75 encysted metacercariae (cysts) were necropsied at 23 weeks postinfection (PI) (160 days PI). Two of the 5 were infected with a total of 33 worms; 23 in one mouse and 10 in the other. Body and organ area measurements showed that these worms were robust and normal in appearance. No signs of atrophy of any of the genital structures were observed. The mean ± SE of eggs/uterus per worm (n = 10) was 243 ± 6. This strain of mouse will be suitable to study the effect of long-term survival on the host–parasite relationship of E. caproni in Balb/c mice.

In 1890, Müller described, from the lung of the cat, a species of nematode which is now known as Aelurostrongylus abstrusus. In 1928, I was able to show that its true habitat was not the lung substance, but the pulmonary artery and its branches, and that its pathogenic action, was mainly, if not entirely, due to the presence of the developing eggs and larvae distributed throughout the lung tissue by the blood stream.

Five out of ten ocellated skinks (Chalcides ocellatus) examined in Dubai between 2007 and 2010 were infected with cestodes of the genus Oochoristica. Out of the 36 collected tapeworms seven specimens were used to describe a new species. Oochoristica chalcidesi n. sp. belongs to the group of species with 25 to 35 testes arranged in two clusters. The lobes of the ovary are subdivided into 4–5 lobules in a similar way as O. ubelakeri described from Agama atra in Namibia. Both species differ in the presence of a neck, a lower number of mature segments in O. chalcidesi n. sp. and a different position of the cirrus pouch in relation to the ovary, as well as in the distribution of uterine capsulae in gravid segments.

The present study examined sequence variation in three mitochondrial DNA (mtDNA) genes, namely cytochrome c oxidase subunit 3 (cox3) and NADH dehydrogenase subunits 1 and 4 (nad1 and nad4), among Ascaridia galli isolates from different geographical localities in China. A portion of cox3 (pcox3), nad1 (pnad1) and nad4 (pnad4) genes were amplified by polymerase chain reaction (PCR) separately from adult A. galli individuals and the amplicons were subjected to sequencing from both directions. The length of the sequences of pcox3, pnad1 and pnad4 were 408 bp, 471 bp and 333 bp, respectively. The intraspecific sequence variations within A. galli were 0–1.7% for pcox3, 0–2.8% for pnad1 and 0–3.4% for pnad4. The A+T contents of the sequences were 67.16–67.65% (pcox3), 67.09–67.94% (pnad1) and 69.91–71.77% (pnad4). The interspecific sequence differences among members of the Ascaridida were significantly higher, being 13.2–30.9%, 12.8–29.0% and 15.1–34.1% for pcox3, pnad1 and pnad4, respectively. Phylogenetic analyses using combined sequences of pcox3, pnad1 and pnad4, with three different computational algorithms (Bayesian analysis, maximum likelihood and maximum parsimony), all revealed distinct groups with high statistical support. These findings demonstrated the existence of intraspecific variation in mitochondrial DNA (mtDNA) sequences among A. galli isolates from different geographical regions in China, and have implications for studying molecular epidemiology and population genetics of A. galli.

Euparadistomum heischi n.sp., the sixth species in the genus, was recovered from a domestic cat on Pate Island, Kenya. In the Dicrocoeliidae, a new subfamily Euparadistominae is proposed for two genera, Euparadistomum Tubangui, 1931 and Stromitrema Skrjabin and Evranova, 1944.

Single and double infections of juvenile Omphiscola glabra (Gastropoda: Lymnaeidae) with Paramphistomum daubneyi and/or Fasciola hepatica were carried out to determine the redial burden and cercarial production in snails dissected at day 60 or at day 75 post-exposure (p.e.) in the laboratory at 20°C. The results were compared with those obtained with single-miracidium infections by Fascioloides magna. Compared to F. hepatica, low values were noted at day 75 p.e. for the prevalence of snail infections with P. daubneyi (4.6–8.3% instead of 23.6–25.9%), the total number of free rediae (10.7–17.9 per snail instead of 26.3–34.7), and that of free cercariae (112.8–136.9 per snail instead of 177.8–248.5). Despite a greater number of free rediae at day 75 p.e. (36.2–45.6 per snail), the prevalences of snail infections with F. magna and cercarial production were similar to those noted for F. hepatica. The results concerning F. hepatica and P. daubneyi might partly be explained by a progressive adaptation of O. glabra to sustain the larval development of these digeneans over the years, as this snail is a natural intermediate host of F. hepatica and P. daubneyi in central France since 1995. Compared with the high number of fully-grown rediae of F. magna in O. glabra, cercarial production seemed limited and this might be explained by the presence of high numbers of rediae which reduced the avaibility of nutrients for cercarial differentiation within the snail.

Estimates of parasite intensity within host populations are essential for many studies of host–parasite relationships. Here we evaluated the seasonal, age- and sex-related variability in faecal water content for two wild ungulate species, springbok (Antidorcas marsupialis) and plains zebra (Equus quagga). We then assessed whether or not faecal water content biased conclusions regarding differences in strongyle infection rates by season, age or sex. There was evidence of significant variation in faecal water content by season and age for both species, and by sex in springbok. Analyses of faecal egg counts demonstrated that sex was a near-significant factor in explaining variation in strongyle parasite infection rates in zebra (P = 0.055) and springbok (P = 0.052) using wet-weight faecal samples. However, once these intensity estimates were re-scaled by the percent of dry matter in the faeces, sex was no longer a significant factor (zebra, P = 0.268; springbok, P = 0.234). These results demonstrate that variation in faecal water content may confound analyses and could produce spurious conclusions, as was the case with host sex as a factor in the analysis. We thus recommend that researchers assess whether water variation could be a confounding factor when designing and performing research using faecal indices of parasite intensity.

1. Ten dogs were given infective larvae of Dracunculus medinensis, originally from human cases in Western Nigeria, and bred in the laboratory in Cyclops leuckarti (Claus).

2. Parasites were found in seven of the dogs when dissected at intervals between 4 hours and 36 days. From an examination of the location of the larvae obtained, both by direct search and by the use of intravenous Evans' blue, it was concluded that they migrated directly through the tissues via the intestinal wall (about 13 hours), abdominal mesenteries (found at 7 and 10 days), and muscles of the abdominal and thoracic wall (15 days). A similar route of migration is believed to take place in cats from an examination of three positive kittens.

3. Almost no increase in length of the larvae occurred during the migration; these measured an average of 0·59 mm. in length after 15 days.

4. No moult was observed up to 36 days but one may have been missed.

Japanese observers have found the encysted cercarire of Heterophyesnocens in the Japanese mullet which belongs to the genus Mugil. In Egypt, Heterophyes heterophyes is a fairly common parasite of man, dog and cat. The genus Mugil “Egyptian mullet” is represented in Egypt by three species.

A biological test to estimate the numbers of infective metacercariae of F. hepatica on pastures is described. The test is shown to be successful provided a snail site can be determined. Results from samples collected from field outbreaks are described and the possible applications of the test are discussed.