In a recent survey of nematodes associated with tobacco in Shandong, China, the root-lesion nematode Pratylenchus coffeae was identified using a combination of morphology and molecular techniques. This nematode species is a serious parasite that damages a variety of plant species. The model plant benthi, Nicotiana benthamiana, is frequently used to study plant-disease interactions. However, it is not known whether this plant species is a host of P. coffeae. The objectives of this study were to evaluate the parasitism and pathogenicity of five populations of the root-lesion nematode P. coffeae on N. benthamiana. N. benthamiana seedlings with the same growth status were chosen and inoculated with 1,000 nematodes per pot. At 60 days after inoculation, the reproductive factors (Rf = final population densities (Pf)/initial population densities (Pi)) for P. coffeae in the rhizosphere of N. benthamiana were all more than 1, suggesting that N. benthamiana was a good host plant for P. coffeae. Nicotiana. benthamiana infected by P. coffeae showed weak growth, decreased tillering, high root reduction, and noticeable brown spots on the roots. Thus, we determined that the model plant N. benthamiana can be used to study plant-P. coffeae interactions.

During nematode surveys of natural vegetation in forests of La Cima de Copey de Dota, San José, San José province, Costa Rica, a Xenocriconemella species closely resembling X. macrodora and related species was found. Integrative taxonomical approaches demonstrated that it is a new species described herein as X. costaricense sp. nov. The new species is parthenogenetic (only females have been detected) and characterised by a short body (276–404 μm); lip region with two annuli, not offset, not separated from body contour; first lip annulus partially covering the second lip annulus. Stylet thin, very long (113–133 μm) and flexible, occupying 30.5–47.8% of body length. Excretory pore located from one or two annuli anterior to one or two annuli posterior to level of stylet knobs, at 42 (37–45) μm from anterior end. Female genital tract monodelphic, prodelphic, outstretched, and occupying 35–45% of body length, with vagina slightly ventrally curved (14–18 μm long). Anus located 6–11 annuli from the tail terminus. Tail conoid and bluntly rounded terminus, the last 2–3 annuli oriented dorsally. Results of molecular characterisation and phylogenetic analyses of D2-D3 expansion segments of 28S rRNA, ITS, and partial 18S rRNA, as well as cytochrome oxidase c subunit 1 gene sequences further characterised the new species and clearly separated it from X. macrodora and other related species (X. iberica, X. paraiberica, and X. pradense).

Adult specimens of Andracantha gravida (Alegret, 1941) were recorded from the intestines of the double-crested cormorant Nannopterum auritus (Lesson) (type host) and brown pelican Pelecanus occidentalis L. in two localities from Mexico: Celestún, Yucatan (south-eastern) and Punta Piedra, Tamaulipas (north-eastern). The specimens of A. gravida are morphologically characterized by having a pipe-shaped body without swellings, the absence of small trunk spines between the two fields of spines on the foretrunk and a cylindrical proboscis with 14–16 rows of 10–12 hooks per row. Newly generated partial sequences of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were generated from adult isolates of A. gravida from Mexico and compared with one sequence of A. gravida and with sequences of other polymorphid acanthocephalans available in GenBank. Phylogenetic analyses based on maximum likelihood and Bayesian inference methods of the cox1 dataset placed all the species of Andracantha in a single clade, with weak support. The analyses of the cox1 dataset placed Andracantha sigma Presswell, García-Varela & Smales, 2018, as sister to the clade formed by A. gravida, Andracantha phalacrocoracis (Yamaguti, 1939), Andracantha leucocarboi Presswell, García-Varela & Smales, 2018 and an unidentified species of Andracantha from Japan. The newly generated cox1 sequences of A. gravida from piscivorous birds of Mexico formed a strongly supported clade with the published sequence of A. gravida from the double-crested cormorant from the south-eastern coast of Mexico. The intraspecific genetic divergence among isolates identified as A. gravida ranged from 0.0% to 2.2%. A cox1 haplotype network inferred with 14 sequences revealed the presence of nine haplotypes, two of which were shared between the populations of piscivorous birds from the north-eastern and south-eastern coasts of Mexico and seven of which were unique. The fixation index between the populations from north-eastern and south-eastern Mexico was low (0.06949), which suggests genetic flow. This can be explained by the migration patterns of the brown pelican and the double-crested cormorant along the coasts of the Gulf of Mexico.

The plant-parasitic cyst nematode Heterodera glycines requires a host plant to complete its life cycle, which involves hatching of infective juveniles that parasitize through root entry. A laboratory population of H. glycines grown on soybean, Glycine max, undergoes a sharp increase in maturity between 5 and 6 weeks in culture, as measured by the proportion of eggs containing well developed pre-hatch juveniles (late development eggs) versus eggs without visible juveniles (early development eggs). The median percent of eggs classified as late development, representing all samples taken from 4 to 7 weeks in culture, was 61%. For all samples taken up to 5 weeks, 80% scored below the median. In samples taken after 5 weeks, 15% scored below the median. This shift in population maturity was accompanied by a significant increase (P < 0.01) in the number of hatched juveniles present in each sample. There was also a significant increase (P < 0.02) in amount of FaRP-like peptide detected by specific ELISA. Total FaRP levels increased from 0.18 ± 0.07 fMol FLRFamide equivalents per ng protein in early development eggs to 0.40 ± 0.17 in late development eggs. The level remained high in hatched juveniles. HPLC/ELISA detected as many as nine potential FaRPs in H. glycines, two of which were specifically increased (P < 0.005) in hatched juveniles. The association of FaRPs with maturing eggs and the possible involvement of these neuropeptides with juvenile hatching and motility are discussed.

Two populations of the species Diastolaimus grossus have been obtained from bark of trees in Bosnia and Herzegovina and the Czech Republic. The species is described and characterized in detail using morphological techniques (light and electron scanning microscopy) and morphometrical (Gower General Similarity coefficient of morphological characters) and molecular analyses, including phylogenetic analysis of all related and already sequenced species of the family Chambersiellidae. Morphological and molecular analyses, based on 18S and 28S ribosomal DNA sequences, show that the family Chambersiellidae is polyphyletic, being the subfamily Chambersiellinae related with Cephalobomorpha and Tylenchomorpha, and the subfamily Macrolaiminae is located into Panagrolaimomorpha. The genus Diastolaimus, previously belonging to Macrolaiminae, is transferred to Chambersiellinae. Diastolaimus mexicanus is proposed as a junior synonym of D. grossus.

The Asian fish tapeworm (Schyzocotyle acheilognathi) is an important fish parasite with a wide host range that infects over 300 species of fish worldwide. Schyzocotyle acheilognathi has been reported from eastern coastal areas of Australia, but has not been previously reported in Western Australia (WA). During a control program for invasive freshwater fishes in south-western WA, a region with a unique and highly endangered freshwater fish fauna, tapeworms identified as S. acheilognathi from their distinctive scolex morphology were found at a prevalence of 3.3% in goldfish (Carassius auratus), 37.0% in koi carp (Cyprinus carpio haematopterus) and 65.0% in eastern gambusia (Gambusia holbrooki) in a small suburban lake to the north of Perth. For molecular confirmation, the 18S ribosomal RNA gene was targeted at hypervariable V4 region. Koi carp isolates were 100% identical to S. acheilognathi isolated from varying hosts, including the red shiner (Cyprinella lutrensis) and a human sample. Sequences obtained from two eastern gambusia were identified as S. acheilognathi, but formed a discrete cluster and may represent a novel genotype. Isolates from two other eastern gambusia and two goldfish formed a distinct clade with only 91.9% similarity to previously sequenced isolates of S. acheilognathi. This emphasizes the importance of molecular identification methods in addition to morphological identification. The presence and potential for transmission of these parasites in south-western WA may threaten the health of native fishes, which are immunologically naïve to this introduced parasite. Immediate control or containment measures should be implemented to halt the spread of these parasites.

This study aimed to describe the shedding pattern of gastrointestinal parasite eggs by a wild population of desert bighorn sheep (DBS; Ovis canadensis) in northern Mexico. Seventy-five fresh faecal samples were collected from the ground in each season within an hour after being expelled by these animals. The generalized linear mixed model showed that eggs per gram of faeces were highest in winter (577 ± 399) and lowest in summer (260 ± 198). Generalized linear models revealed that Strongyloides spp. predominated during most seasons with a peak in summer (85% of faecal samples analysed) and the absence of this helminth in winter. Nematodirus spp. was another helminth present in three seasons, with the presence of this nematode in 35% of the faecal samples in spring and 0% in summer. Other parasites in DBS faeces included Bunostomun spp., Trichostrongylus spp., Cooperia spp., Mecistocirrus digitatus, Haemonchus contortus, Chabertia ovina and Eimeria ovinoidalis. There were differences among seasons in the percentage of these helminths and coccidia in faecal samples for all these parasites. It was concluded that helminths egg output in DBS in a semi-arid rangeland is lowest in summer and spring and highest in autumn and winter. Furthermore, it was shown that DBS in the study site do not suffer from severe parasite burden. Therefore, this nematode parasite burden is compatible with the conservation and well-being of this particular population.

Two species of the genus Aporcella, one new and one previously known, collected from cultivated fields in Iran are studied. Description, morphometrics, illustrations (both line and microphotographs) and D2–D3 sequences are provided for Aporcella talebii sp. n., which is characterized by its 1.66–2.02-mm-long body, lip region offset by constriction and 15–17 μm broad, odontostyle 14–17.5 μm long, neck 412–484 μm long, pharyngeal expansion occupying 46–50% of total neck length, uterus simple and 1.6–2.0 times the corresponding body diameter long, V = 52–59, tail conical (40–50 μm, c = 37–47, c′ = 1.1–1.4) with a weak but perceptible dorsal concavity at the end and male absent. Morphometrics, microphotographs and D2–D3 sequences of Aporcella simplex are also presented, this being its first Asian record. Molecular analyses confirm the monophyly of the genus, its close relationship with other taxa lacking pars refringens vaginae and the polyphyly of Aporcelaimidae.

A new species of Paurodontoides, P. siddiqii n. sp., is described and illustrated based on its morphological, morphometric, and molecular characters. The new species is characterized by a female 550–729 μm long, lip region continuous with body contour, stylet length 7.0–8.0 μm long or c. 1.0–1.2 times the lip region diameter, lateral fields with four smooth incisures, excretory pore at 85–125 μm from anterior end located at the base of the pharyngeal bulb or posterior to it, basal pharyngeal bulb with a short posterior extension projecting into the intestine, monodelphic–prodelphic reproductive system with prominent 19–22 μm long post-uterine sac, and elongate conoid tail with a filiform terminus. The new species is compared with two known species of the genus. It differs from the type species of the genus, P. linfordi, by having slightly shorter stylet, lateral field with smooth incisures, different position of the excretory pore, and absence of male. Compared to P. latus, the new species has a shorter body, shorter stylet, different position of the excretory pore, female tail shape and absence of male. The new species was also compared with close species of the genus Paurodontus because of lateral field marked with four lines, asymmetrical stylet knobs and absence of male. Molecular phylogenetic studies of the new species using partial sequences of 18S rDNA revealed that it forms a clade with a species of the genus Ficotylus. In phylogenetic analyses using partial sequences of the 28S rDNA D2-D3 domain, the new species formed a monophyletic group with a species of the genus Veleshkinema and Sphaerularia spp. (Sphaerulariinae).

Interspecific interactions between parasites sharing the same host are often antagonistic; the presence of one species decreases the number of individuals or negatively affects both the distribution and reproduction of the other species. Antagonistic interactions between co-infecting parasites may translate into direct competition or interactive segregation, but elements of both may be present. Potential interactions between two acanthocephalan species, Pomphorhynchus laevis and Acanthocephalus anguillae, were studied in the field in two of their natural fish definitive hosts. There was no evidence for competitive exclusion between P. laevis and A. anguillae. However, a negative interaction was found for the first time in the field between these two species. Based on the analysis of parasite abundance and total biomass using a static regression approach, I found that the abundance and total biomass of parasites was also limited by host characteristics. These results are consistent with previous laboratory studies on competition between P. laevis and A. anguillae.

The nematode Mooleptus rabuka is recorded in the digestive tract of catshark Apristurus fedorovi caught at the Imperial Ridge (Pacific Ocean). Important morphological features such as the number of cephalic and caudal papillae, the position of amphids and the shape of the gubernaculum are detailed in this parasite species. According to the phylogenetic analyses based on the 18S ribosomal RNA gene sequences, M. rabuka forms a lineage, Mooleptinae nom. nov., which is close to the gnathostomatid genus Echinocephalus (maximum likelihood analysis), or else forms a polytomy with this genus and the lineages of Anguillicola + Spiroxys and Tanqua + ‘Linstowinema’ sp. (Bayesian inference analysis). Overall, our findings do not support the monophyly of the Gnathostomatidae. We elevate spiroxyines to the family status, Spiroxyidae stat. nov., and temporarily consider the Gnathostomatidae to include the following subfamilies: Ancyracanthinae Yorke & Maplestone, 1926, Gnathostomatinae Railliet, 1895 sensu lato and Mooleptinae nom. nov. The name Mooleptinae nom. nov. is suggested instead of the Metaleptinae Moravec & Nagasawa, 2000, which is based on a preoccupied generic name Metaleptus Machida, Ogawa & Okiyama, 1982.

Eurytrematosis is a disease caused by flukes of the genus Eurytrema. These parasites infect the pancreatic ducts of a wide variety of species, including cattle, sheep and humans. Diagnosing eurytrematosis through the analysis of faecal samples can be difficult because most of the available techniques are considered of low sensitivity. In this context, a modification of the Dennis, Stone and Swanson technique (Belem Sedimentation Technique, BST) was previously developed to increase the probability of detecting infected animals; nevertheless, the values of eggs per gram obtained using the modified technique are generally low. We proposed a modification of the this technique (MBST), to increase the sensitivity and detection rate of infected animals. The objective of this work was to describe MBST and compare it with BST. Faecal samples of 212 clinically healthy animals (174 from cattle and 38 from sheep) from 20 farms were taken by the intra-rectal route and stored at 4°C. The samples were processed using BST and MBST. Positive samples amounted to 55 (25.9%) using BST and 121 (57.1%) using MBST. In the simples from cattle, 52 (29.8%) and 107 (61.4%) were positive in BST and MBST, respectively. In sheep, three (7.8%) and 14 (36.8%) positive samples were obtained in BST and MBST, respectively.The results obtained using the two methods were significantly different, indicating a lack of agreement between their findings. The results suggest that MBST is a more sensitive method to detect Eurytrema spp. eggs in faeces than BST.

In this study, we report the first complete mitochondrial genome of the tapeworm Nippotaenia mogurndae in the order Nippotaeniidea Yamaguti, 1939. This mitogenome, which is 14,307 base pairs (bp) long with an A + T content of 72.2%, consists of 12 protein-coding genes, 22 transfer RNA (tRNA) genes, two rRNA genes, and two non-coding regions. Most tRNAs have a conventional cloverleaf structure, but trnS1 and trnR lack dihydrouridine arms of tRNA. The two largest non-coding regions, NCR1 (220 bp) and NCR2 (817 bp), are located between trnY and trnS2 and between nad5 and trnG, respectively. Phylogenetic analyses of mitogenomic data indicate that N. mogurndae is closely related to tapeworms in the order Cyclophyllidea.

Tetraspanins are a superfamily of transmembrane proteins that in flatworms have structural roles in the development, maturation or stability of the tegument. Several tetraspanins are considered as potential candidates for vaccines or drugs against helminths. Monopisthocotylean monogeneans are ectoparasites of fish that are health hazards for farmed fish. The aim of this study was to identify in silico putative tetraspanins in the genomic datasets of four monopisthocotylean species. The analysis predicted and classified 40 tetraspanins in Rhabdosynochus viridisi, 39 in Scutogyrus longicornis, 22 in Gyrodactylus salaris and 13 in Neobenedenia melleni, belonging to 13 orthologous groups. The high divergence of tetraspanins made it difficult to annotate their function. However, a conserved group was identified in different metazoan taxa. According to this study, metazoan tetraspanins can be divided into 17 monophyletic groups. Of the 114 monogenean tetraspanins, only seven were phylogenetically close to tetraspanins from non-platyhelminth metazoans, which suggests that this group of proteins shows rapid sequence divergence. The similarity of the monopisthocotylean tetraspanins was highest with trematodes, followed by cestodes and then free-living platyhelminths. In total, 27 monopisthocotylean-specific and 34 flatworm-specific tetraspanins were identified. Four monogenean tetraspanins were orthologous to TSP-1, which is a candidate for the development of vaccines and a potential pharmacological target in trematodes and cestodes. Although studies of tetraspanins in parasitic flatworms are scarce, this is an interesting group of proteins for the development of new methods to control monogeneans.

From time to time attempts have been made to control the spread of sclerostome larvae by treating the manure before use on the pastures or by mechanical means such as ploughing the land to bury the larvae. Various chemicals have been used, including artificial manures and animal waste products. Lucker (1936) buried larvae at varying depths in soils of different quality and measured the percentage that appeared on the surface during periods up to six weeks. Clay soils were almost a complete barrier to vertical migration whereas sandy soils and coarse sand permitted migration, during a period of 3–8 weeks, of appreciable numbers when buried 1–6 inches. He suggests from this evidence that ploughing the land would bury the larvae and therefore reduce the number of infective larvae available to the stock. It would seem to the writer, however, that there is a fallacy in this argument. Ploughing the land would turn the soil over but, even if a plough press were used, many fissures would be left which might form an easier channel for migration to the surface. Infective larvae readily accomplish horizontal migration and the possibility of lateral migration along the overturned turf and up the fissures must not be overlooked. The action of frost and the presence of roots in the overturned sod would possibly be other factors in encouraging vertical migration, not to mention the subsequent preparation of the land required before seeding down again for permanent pasture.

The biochemistry and histochemistry of Pegosomum egretti have been studied using standard techniques. Phosphatases were analysed colorimetrically; the optimum pH for acid phosphatase activity was 5·0 and for alkaline phosphatase was 10·0. The results were compared with those of other trematodes. Histochemical localization of acid and alkaline phosphatases revealed differences in enzyme activity in various tissues. These differences in the site and pattern of distribution of the two enzymes have been discussed in relation to transport of raw materials and the metabolism of the cell concerned.

Attempts have been made to increase the survival rate of third-stage larvae of Parastrongylus cantonensis during cryopreservation. Parasites were obtained from experimentally infected snails, Biomphalaria glabrata. The maximum non-toxic concentrations of cryoprotectants dimethyl sulphoxide (DMSO) and glycerol were determined as 10% v/v in NCTC 109 medium. Different pre-cooling times and serum additives were assayed to determine their effects on the viability of larvae. Larvae pre-cooled at –20°C for 15–20 minutes before transfer to –70°C had the optimum survival rate. The presence of serum was essential for further cooling to –196°C. There were no differences between native and heat-inactivated sera on the larval viability. The survival of larvae recovered after storage at –196°C was higher in sera collected from the rat, man, or fetal calf than in sera collected from the mouse, dog, or horse. Viability assessed by mouse-infections showed that thawed larvae retained infectivity for susceptible hosts, but it was significantly lower than that of unfrozen control worms.

Oesophagostomum multifoliatum, previously known to occur only in Kenya, Rhodesia and Tanzania, was found on the Jos Plateau of Nigeria in cattle. Of the 120 cattle examined post-mortem, 78 (65%), were found to be infected. The faecal egg, of which only the size was hitherto known, is described and figured; it shows striking similarities to that of Nematodirus. The possibility is expressed that O. muitifoliatum might have been mistaken for the more familiar but closely related species O. radiatum and O. columbianum or its egg with that of Nematodirus; it is probable that it is much more widespread than hitherto thought.

Tetrameres fissispina (Diesing, 1861) is recorded for the first time from the Wood-Pigeon, Columba palumbus L., and Stock Dove, C. oenas L.

An account is given of a natural infection of Wood-Pigeons with T. fissispina during the winter months of 1962/63 and 1963/64 in Cambridgeshire.