Adult trematodes, morphologically similar to Haplosplanchnus pachysomus (Eysenhardt, 1829), were extracted from the intestine of Mugil cephalus Linnaeus, 1758, collected in the Black Sea basin. Morphological, morphometric and 28S ribosomal DNA (rDNA) partial sequence data were obtained for these trematodes following comparative analysis with previous data on this species. Worms from this study were morphologically identical to all previously reported H. pachysomus specimens from different locations. The results of the morphometric analysis indicated general similarity between H. pachysomus from the Black Sea and trematodes from Vietnam and Australia. Trematodes from the Black Sea and specimens from Spain were identical based on 28S rDNA partial sequences; however, these sequences differed from that of H. pachysomus from Vietnam and Australia by eight fixed substitutions. Overall, our results indicate that H. pachysomus from Spain and the Black Sea and from Vietnam and Australia can presently be considered as two cryptic species, one in Palaearctic and one in Indo-West Pacific regions. Our results provide a molecular base for including Haplosplanchnus purii in the genus Provitellotrema or to consider H. purii, P. crenimugilis and H. pachysomus within the same genus.

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.

The ability of two isolates of the nematode-trapping fungus Duddingtonia flagrans to reduce the numbers of gastrointestinal nematode larvae on herbage was tested in three plot studies. Artificially prepared cow pats containing Ostertagia ostertagi eggs, with and without fungal spores, were deposited on pasture plots two or three times during the grazing season in 1995, 1996 and 1997. The herbage around each pat was sampled fortnightly over a period of 2 months and the number of infective larvae was recorded. At the end of the sampling period, the remainder of the faecal pats was collected to determine the wet weight, dry weight, and content of organic matter. The infective larvae remaining in the pats were extracted. Faecal cultures showed that both fungal isolates significantly reduced the number of infective larvae. Significantly fewer larvae were recovered from herbage surrounding fungus-treated pats compared with control pats in all three experiments, reflecting the ability of the fungus to destroy free-living larval stages in the faecal pat environment. After 8 weeks on pasture there were no differences between control and fungus-treated pats with respect to wet weight, dry weight, and organic matter content. This indicates that the degradation of faeces was not negatively affected by the presence of the fungus.

Starting with eggs from a natural habitat the authors were able to raise and breed Bulinus truncatus, the snail vector of schistosomiasis haematobia, under conditions of total and continuous darkness and to complete the life-cycle from egg to egg in 70 days. The rearing of a second generation was interrupted by circumstances beyond the authors’ control. Darkness is shown nevertheless to have a restrictive effect on population growth and the use of covered channels and pipes for irrigation water, although not a complete control measure, should therefore be adopted wherever possible in endemic foci of schistosomiasis haematobia where snail control is necessary.

Resistance against an infective organism is a self evident requirement for healthy survival within the endemic area of any spreading disease, the most constant and the most effective force being the immunity that is acquired as a result of infection. In developed parts of the world most members of the human community must go through the process of acquiring resistance to measles, mumps and chicken pox in order to have assurance that they will not at some time be incapacitated by one or the other. The dog community is in a similar position with regard to distemper. This principle for preparation to live healthy in an infected environment is widely accepted for the microbial crowd—diseases of man and animals, but has not so far received general acceptance for diseases caused by parasitic worms.

Early in 1934 the writer received from Prof. Mario Curzi of Rome an agar tube culture on which were growing, in addition to bacteria and a fungus belonging to the genus Fusarium, a number of nematodes which Prof. Curzi wished to have identified. The majority of the nematodes proved to belong to the genus Cylindrogaster whilst the others were found to be Aphelenchus avenae Bast.

Proteolytic activities in extracts from the plant-parasitic nematodes Heterodera glycines and Meloidogyneincognita were examined for their abilities to digest three FRET-modified peptide substrates representing members of the large FMRFamide-like peptide (FLP) family in nematodes. Included were sequences distributed across all nematode species (KSAYMRFa and KHEYLRFa) and a sequence confined to a narrow range of plant-parasitic nematodes (KHEFVRFa). Species variations were observed among substrate affinities, reaction rates and effect of protease inhibitors. Km values for KHEYLRFa (1.48 ± 0.34 μm) and KSAYMRFa (2.13 ± 0.24 μm) in H. glycines were each lower (P< 0.05) than those for the same substrates in M. incognita (5.26 ± 1.30 μm and 3.90 ± 0.61 μm, respectively). The Km of KHEFVRFa was lower (P< 0.05) in M. incognita (5.83 ± 0.36 μm) than in H. glycines (11.01 ± 1.26 μm). Reaction rates (Vmax/min/μg) for KHEYLRFa were the same for both species, but KSAYMRFa and KHEFVRFa digestion rates were each nearly twofold higher (P< 0.05) in M. incognita than in H. glycines. Digestion of KSAYMRFa was strongly inhibited in both species by 4-(2-aminoethyl)-benzenesulfonyl-fluoride-HCl (AEBSF) and EDTA, but M. incognita was more sensitive (P< 0.05) to inhibition. AEBSF and EDTA (both at 1 mm) inhibited M. incognita activity 62.3% and 36.6% more, respectively, than H. glycines activity. Serine protease inhibition differed significantly (P< 0.05) between the two species. Maximum inhibition of M. incognita (76%) occurred at 1.85 mm AEBSF while maximum inhibition of H. glycines was 40% at 1.19 mm AEBSF.

Nilocotyle duplicisphinctris sp. n. was recovered from the stomach of Hippopotamus amphibius in Ethiopia. The average body size (L × W) is 3.6 × 1.2 mm; pharynx 0.5 × 0.3, Dicranocoelium type; other diameter of the acetabulum 0.85, Nilocotyle type; anterior testis 0.34 × 0.49; posterior testis 0.32 × 0.27; ovary 0.27 × 0.19; genital opening 0.30 × 0.34, Duplicis phinctris type and eggs 0.15 × 0.07. The most characteristic specific feature is the presence of a double sphincter along the genital atrium.

Phyllodistomum pepirense n. sp. is described from the urinary bladder of Hoplias malabaricus (Bloch, 1794), sampled in the Jacaré-Pepira River in São Paulo state, Brazil. The isolates of the new species were recovered as a monophyletic group in the phylogenetic analysis of the 28S rRNA gene, which showed the new species as the sister taxa of Phyllodistomum virmantasi Pinacho-Pinacho, Sereno-Uribe, Hernández-Orts, García-Varela & Pérez-Ponce de León, 2021, a species sampled from an eleotrid fish in Southeastern Mexico. The new species differs morphologically from P. virmantasi by having a larger body size, slightly lobed testes and ovary, a mostly intercaecal uterus, slightly diverticulated caeca, and vitelline masses irregularly shaped. The new species is also readily distinguished from other species of Phyllodistomum Braun, 1899 reported from freshwater fishes in Brazil – namely, P. rhamdiae Amato & Amato, 1993 and P. spatula Odhner, 1902. The new species is herein described based on morphological characteristics, molecular data from D1–D3 domains of the 28S rRNA gene, host association, and geographical distribution.

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.

Laboratory experiments have shown that cysts of the eelworm Heterodera schachtii adhering to seed potato tubers are killed by immersion of the tubers for 6 hours in 5% formalin solution (Franklin 1939). Further experiments were designed to determine what effect such treatment has on the seed tubers and on the resulting crop.

The mallard Anas platyrhynchos is the most abundant water bird species in Austria, but there is no record of its helminth community. Therefore, this work aimed to close that gap by recording and analysing the parasite community of a large number of birds from Austria for the first time. A total of 60 specimens shot by hunters in autumn were examined for intestinal parasites. The following taxa were recovered (prevalence given in parentheses): Cestoda: Diorchis sp. (31.7%) and Fimbriarioides intermedia (1.7%); Acanthocephala: Filicollis anatis (5%), Polymorphus minutus (30%) and one cystacanth unidentified (1.7%); Trematoda: Apatemon gracilis (3.3%), Echinostoma grandis (6.7%), Echinostoma revolutum (6.7%) and Notocotylus attenuatus (23.3%); Nematoda: Porrocaecum crassum (1.7%) and one not identified (1.7%). The frequency distribution of parasites showed a typical pattern in which 39 birds (65%) were either not parasitized or were harbouring up to five worms, whereas more intense infestations occurred in a lesser number of hosts. Compared to other studies from central and eastern Europe, an extremely depauperate helminth community, particularly of the cestodes and nematodes, was found. Polymorphus minutus was observed as having highly variable morphology and, therefore, molecular genetic characterization by DNA barcoding was carried out. Species identification was confirmed by comparing data with the reference cytochrome c oxidase subunit 1 gene sequence from P. minutus available in GenBank.

The present paper describes the taxonomy of two new monogeneans, namely, Thaparocleidus longiphallus sp. n. and T. siloniansis sp. n., based on morphological, morphometric and molecular biological analysis, collected from the fish Wallago attu (Bloch & Schn.) and Silonia silondia (Ham.), respectively, at Meerut, UP, India. Genetic characterization of the two new species is based on sequence analyses of the rDNA 28S gene using neighbour-joining and maximum-parsimony techniques. These methods are congruent in depicting T. longiphallus sp. n. and T. siloniansis sp. n. as closely related species, but distinct from each other and forming a subclade with other species of the genus Thaparocleidus Jain, 1952. Secondary-structure models of the large subunit rDNA of the two species were also predicted using a combined comparative and thermodynamic approach. Molecular morphometric and phylogenetic relationships of the isolates of the Thaparocleidus species are discussed in detail.

A total of 140 trout were examined from four lakes in north west Ireland, Loughs Craghy, Waskel, Meela and Owennamarve. Eleven species of metazoan parasite were recorded, ten of which were of freshwater origin and Anisakissp. was the only marine species. No acanthocephalan species were found. Diphyllobothrium ditremum, D. dendriticum and Anisakissp. were the only allogenic species. Lough Owennamarve had the largest component community with nine species recorded. Lough Meela, the only brackish water lake had the smallest component community with six species recorded. Lough Waskel and Craghy had intermediate component community values. Lough Meela showed the lowest levels of similarity to any of the other lakes. Values for the Shannon-Wiener diversity index were highest for Lough Owennamarve and lowest for Lough Meela and intermediate for the other two lakes. Lough Meela had the highest values for the Simpson's dominance index and the Berger-Parker index. Lough Owennamarve had the highest Brillouin's index and Lough Meela had the lowest. The use of multiple regression techniques to control for the potentially confounding effect of geographical distance as a predictor of community similarity was discussed. No parasite species found could be considered as regionally and locally abundant and therefore described as a core species. The helminth community appears to have some degree of predictability, but chance colonization events are also important.

Photoperiodic emergence patterns of the cercariae of two digeneans, Echinoparyphium recurvatum (Echinostomatidae) and Plagiorchissp. (Plagiorchiidae), were studied experimentally using a photoperiodic regime of 12 h light: 12 h dark at a constant 18°C. In single species infections of the first intermediate host snail Lymnaea peregra, the cercariae of E. recurvatum emerged exclusively during the light phase and those of Plagiorchis sp. emerged exclusively during the dark phase. In double infections, each species retained its own discrete photoperiodic emergence pattern. This result demonstrates the absence of interference between the mechanisms responsible for the photoperiodic emergence pattern of each species. A degree of interference between the two parasites in double infections of L. peregra was evident. The presence of E. recurvatum significantly reduced the number of Plagiorchis sp. cercariae emerging in a 24 h period and also delayed the mean peak emergence time of Plagiorchissp. cercariae by 2 h. This result is consistent with the well documented antagonistic effect that the redial stages of echinostomes are known to have against the sporocysts of other digeneans within the same host mollusc.

Acanthocephalans are a group of obligate endoparasites that alternate between vertebrates and invertebrates to complete their life cycles. Occasionally, the same individual host acts as a definitive or paratenic host for different acanthocephalan species. In this study, acanthocephalans were sampled in marine fish in three localities of the Yucatán Peninsula; adults and cystacanths were recovered from the intestine and body cavity, respectively, of Haemulon plumierii from off the coast of Sisal, Yucatán. Ribosomal DNA sequences (small and large subunits) were used to test the phylogenetic position of the species of the genus Dollfusentis, whereas the mtDNA gene cox 1 was used for assessing species delimitation. The cox 1 analysis revealed an independent genetic lineage, which is recognized herein as a new species, Dollfusentis mayae n. sp. The new species is morphologically distinguished from the other six congeners by having a cylindrical proboscis armed with 22–25 longitudinal rows bearing 12 hooks each. The cystacanths were morphologically identified as Gorgorhynchus medius by having a cylindrical trunk covered with tiny irregular spines on the anterior region, and a cylindrical proboscis armed with 17–18 longitudinal rows of 21 hooks each; small and large subunit phylogenetic analyses yielded G. medius within the family Isthomosacanthidae, suggesting that Gorgorhynchus should be transferred to this family from Rhadinorhynchidae where it is currently allocated.

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.

Six families belonging to the Paramphistomoidea superfamily have been reported in South America, with only Zonocotylidae and Balanorchiidae being endemic. The Zonocotylidae was initially classified as Aspidogastrea and then as a paramphistomoid. This family comprises a single genus, Zononocotyle, with two species. It is primarily characterized by having an attachment organ with transverse ridges and a single testis. The placement of Zonocotylidae within Paramphistomoidea is controversial, as some researchers speculate that this genus is the most primitive member of the superfamily, while others consider it an aberrant form. The main objectives of our study were to provide the first sequences of Zonocotylidae and elucidate its phylogenetic position. We amplified the 28S gene from two parasites from Cyphocharax sp. from Punta Lara, Buenos Aires. Newly generated sequences were used to infer the phylogenetic relationships with other Paramphistomoidea species using a Bayesian approach. Zonocotylidae were clustered with Dadayiinae and Kalitrematinae (Cladorchiidae) species found in freshwater fishes from South America. Genetic analyses revealed that they formed a well-supported clade with cladorchiids in freshwater hosts from South America. However, the occurrence of genera of Cladorchiidae in North America, Middle America, Asia, and Australia suggested its polyphyletic nature and may indicate the need for the erection of new families. Other Paramphistomoidea families may also require further revision. The addition of new sequences to phylogenetic analyses along with a comprehensive and more detailed description of the genera will help resolve the relationships within this group.

Trichinosis is a global food-borne zoonotic disease. Most drugs used in its treatment have low bioavailability and reduced activity against larvae. Therefore, there is an urgent need for safe and effective medications. This study aimed to investigate the in vivo anti-parasitic and anti-inflammatory efficacy of olibanum (OL) extract, alone or combined with albendazole (ABZ) during both intestinal and muscular phases of trichinosis. Male Swiss albino mice (n = 130) were allocated to seven groups, with 20 mice in each group except for the negative control group (10 mice): negative control (GI), positive control (GII), OL25- treated (GIII), OL50- treated (GIV), ABZ50- treated (GV), OL25 + ABZ25 (GVI), and OL50 + ABZ25 (GVII). For intestinal and muscular phase analysis, each group was divided into two subgroups based on euthanizing day (6 and 35 days post-infection). The drug’s efficacy was evaluated through parasitological, biochemical, histopathological, and immunohistochemical studies. OL extract at both concentrations (25 mg/kg/d, 50 mg/kg/d) significantly reduced adult (53.7% and 68.1%, respectively) and larval counts (57.3% and 78.8%, respectively). It improved the histopathological changes in intestine and muscle. The expression of CD8+ T cells and the serum level of IL-10 increased significantly during both intestinal and muscular phases (P < 0.05) in OL50 treated mice. Additionally, OL decreased abnormal levels of liver enzymes (ALT & AST). Its effects were dose-dependent in both adult and larval stages. In conclusion, OL exhibits promising in vivo activity against both stages of Trichinella spiralis infection, particularly at the intramuscular phase. It can be safe as an alternative treatment for trichinosis.