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During November of 2007, parasitic nematodes were collected from 161 specimens of 32 freshwater fish species in the Lacantún River of the Lacandon rain forest of Chiapas, southern Mexico. Recent detailed morphological and taxonomic studies of this material revealed the presence of 17 nematode species (12 adult and 5 larval) of nine families, including Cucullanus potamarii sp. n. from the intestine of the ariid catfish Potamarius usumacintae Betancur-R et Willink, which is endemic to the Usumacinta River basin to which the Lacantún River belongs. This new species is mainly characterised by deirids and the excretory pore located far posterior to the level of the oesophago-intestinal junction, which is an almost unique feature among its congeners. Most parasites are briefly described and illustrated, and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Some findings represent new host and geographical records. Cucullanus oaxaquensis Caspeta-Mandujano, Salgado-Maldonado et Martínez-Ramírez, 2010 is considered a junior synonym of Cucullanus angeli Cabañas-Carranza et Caspeta-Mandujano, 2007, and Neocucullanus marcelae Ramallo, 2012 a species inquirenda. Based on absence of relevant morphological differences, Rhabdochona ictaluri Aguilar-Aguilar, Rosas-Valdez et Pérez-Ponce de León, 2010 is considered a synonym of Rhabdochona kidderi Pearse, 1936.

According to studies, latent Toxoplasma gondii infection may affect several functions of the human brain. Here we search for the association between latent toxoplasmosis and cognitive performance. We tested 70 individuals for latent T. gondii infection. There were 26 Toxoplasma-infected subjects and 44 Toxoplasma-free subjects. Within these two groups we assessed cognitive performance using a set of standardized, widely recognized neuropsychological tests: Trail Making Test, Stroop Test, Verbal Fluency Test, Digit Span Test and N-back test. The relationship between chronic toxoplasmosis and cognitive performance was assessed, with adjustment for age and sex. Patients with latent toxoplasmosis performed worse on one neuropsychological test, N-back Test - percentage of correct answers (β -8.08; 95%CI -15.64 to -0.53; p<0.05) compared to seronegative patients. However, after adjustment for age and sex, no statistically significant associations between latent toxoplasmosis and the scores on any cognitive tests were noticed. As statistically significant relationship was not observed, this study does not confirm that chronic latent T. gondii infection affects cognition.

The eye nematode Thelazia callipaeda Railliet et Henry, 1910 (Spirurida: Thelaziidae) is a vector-borne zoonotic nematode infecting a range of wild and domestic carnivores as well as humans. It is considered to be a causative agent of emerging and neglected disease and currently invades central part of Europe. Nematodes were collected from the eye of a dog living in Prague, which never travelled outside the Czech Republic. The nematodes were identified based on their morphology and partial sequence of the cox1 gene as T. callipaeda haplotype 1. This finding represents the northernmost record of autochthonous canine thelaziosis in Europe. The insufficient control of imported animals as well as free movement of dogs and wild carnivores within Europe probably facilitates spreading of T. callipaeda throughout the continent. To better understand the spreading of T. callipaeda and to prevent its zoonotic transmissions, information about the risk of this infection in newly invaded countries should be disseminated not only among veterinarians and physicians, but also within the community of pet owners and hunters.

The glochidium larvae of freshwater mussels of the family Unionidae need to find suitable hosts to attach themselves and metamorphose into free-living juveniles. The specificity of the host-parasite relationship was investigated for the Iberian Unio tumidiformis Castro, 1885 by means of experimental infections and also by analyzing naturally infected fish. The process of encapsulation of glochidia was studied using scanning electron microscopy. Unio tumidiformis has proven to be an unusual host-specific unionid mussel, apparently parasitizing only fish of the genus Squalius Bonaparte, 1837. Successful encapsulation or complete metamorphosis was observed in five fish taxa: S. aradensis (Coelho, Bogutskaya, Rodrigues et Collares-Pereira), S. caroliterti (Doadrio), S. pyrenaicus (Günther), S. torgalensis (Coelho, Bogutskaya, Rodrigues et Collares-Pereira) and S. alburnoides (Steindachner) complex (only for the nuclear hybrids with at least one copy of the S. pyrenaicus genome). Complete metamorphose was achieved in 6 to 14 days at mean temperatures ranging from 21.8 to 26.1°C. The current study provides support for cell migration being the main force of cyst formation and shows the influence of potential host's genome in response to the infection process to determine the success of the metamorphosis.

Three species of amphibian-parasitic acanthocephalans belonging to the genus Pseudoacanthocephalus Petrochenko, 1958 have been recorded in Japan. However, only a limited number of localities have been surveyed, and the distribution of these congeners across other regions of Japan remains unclear. In this study, acanthocephalans of the genus Pseudoacanthocephalus were recovered from both definitive (Rana ornativentris Werner - type host, and Zhangixalus arboreus [Okada et Kawano]) and accidental hosts (Scyliorhinus torazame [Tanaka]) from Sado Island, Japan. Morphological analyses indicate that those specimens represent a new species, Pseudoacanthocephalus sadoensis sp. n., which may be endemic to the island. Additionally, our report of the incidental occurrence of this species in a marine elasmobranch represents the first documented case of a Pseudoacanthocephalus species found in a marine host.

The present study describes the morphology and phylogenetic position of two specimens of Bertiella Stiles et Hassall, 1902 (Cestoda, Anoplocephalidae) from Rattus tanezumi (Temminck) (Muridae) from Đồng Tháp Province in southern Vietnam. The phylogenetic analysis was based on sequences of the large subunit ribosomal RNA gene (28S). The specimens were described and shown to be morphologically similar to Bertiella anapolytica Baylis, 1934 from Rattus spp. from Indonesia (Sumatra, type locality) and Australia, except for a few quantitative differences. The identification was confirmed by the phylogenetic analysis, which showed a strong affinity and fairly limited genetic divergence between the specimens from Vietnam and Australia. This is the first verified case of Bertiella in murid rodents from continental Eurasia. The uterine pore and associated canal present in the posterolateral corners of gravid proglottids of B. anapolytica are considered to form a true, functional structure used for egg release prior to apolysis. The phylogenetic analysis suggested that B. anapolytica has diverged as a consequence of a shift from marsupials, which probably took place east of the Wallace's line, either in Wallacea or Australasia. The presence of B. anapolytica west of the Wallace's line (Vietnam, Sumatra), where marsupials are absent, may be explained by a westward dispersal in commensal rats, possibly Rattus exulans (Peale), a species transported throughout the Pacific and South-East Asia by prehistoric people.

Ixodes inopinatus Estrada-Peña, Nava et Petney, 2014 was described in 2014 from the Iberian Peninsula and later reported from Algeria, Morocco, Tunisia, Germany, Austria and Romania. However, recent studies raised serious doubts about the presence of I. inopinatus in Central Europe and reported hybridisation between the Ixodes ricinus (Linnaeus, 1758) and I. inopinatus. In this study, we selected a locally common rodent host, the edible dormouse Glis glis (Linnaeus) (Rodentia: Gliridae), to study the prevalence of these two tick species and their hybrids in a Central European woodland. The TROSPA nuclear gene and the COI mitochondrial gene were used for tick identification. Overall, 581 dormice were screened and 383 I. ricinus, 17 I. ricinus/inopinatus hybrids and no I. inopinatus were found. Co-infection of I. ricinus and hybrids was found on 11 dormice with the overall prevalence of I. ricinus 28.8% and hybrids 2.5%. Seasonal occurrence of I. ricinus and hybrids reached a peak in August. Edible dormouse males were more frequently infected than females and larvae of both tick taxa greatly outnumbered the nymphs. Detection of a large number of hybrid larvae on this mammal host demonstrates that tick hybridisation likely occurs further north and outside the originally described distribution range of I. inopinatus.

Latent infection with Toxoplasma gondii (Nicolle et Manceaux, 1908) has been repeatedly correlated with behavioural and physiological changes in both humans and animals. While classically regarded as a parasite transmitted via ingestion or vertical (transplacental) transmission, accumulating evidence suggests that sexual transmission may also contribute to its epidemiology. This review explores the hypothesis that some behavioural effects of toxoplasmosis - especially those related to attraction, sexual activity, and mate choice - may have evolved to facilitate sexual transmission of the parasite. We summarise findings from animal models and human studies that show modified sexual preferences, altered sexual activity, enhanced attractiveness in infected individuals, and elevated prevalence of T. gondii in groups exhibiting high sexual activity or non-traditional sexual behaviour patterns. Particular attention is given to the role of testosterone, which may mediate both behavioural changes and reproductive consequences, such as shifts in offspring sex ratios and fertility outcomes. Direct detection of the parasite in semen and evidence of transmission through insemination in non-human species further support the plausibility of this route. The observed behavioural effects may also intersect with mechanisms previously thought to enhance predation risk, such as altered fear responses to felid odours. Taken together, these findings point to the possibility that sexual transmission, while likely secondary in humans, may have played a more substantial role in the evolutionary history and current ecology of T. gondii than previously appreciated. This perspective also provides an alternative interpretative framework for understanding the broad spectrum of phenotypic changes associated with latent toxoplasmosis. Further interdisciplinary research is required to clarify the relative contribution of sexual transmission to the parasite's life cycle and to assess its implications for public health and theory of host-parasite coevolution.

Adult specimens of five little-known species of spiruridan nematodes (Spirurida) were collected during occasional examinations of some fishes from the Poonch River in Jammu and Kashmir, India: Procamallanus (Spirocamallanus) bilaspurensis Gupta et Duggal, 1973 in Mastacembelus armatus (Lacépède) (Mastacembelidae, Synbranchiformes), Rhabdochona (Rhabdochona) indica Moravec, Scholz, Ash et Kar, 2010 in Crossocheilus latius (Hamilton) (Cyprinidae, Cypriniformes), Rhabdochona (Rhabdochona) turkestanica (Skryabin, 1917) in Schizothorax richardsonii (Gray) (Cyprinidae, Cypriniformes) and both Rhabdochona (Rhabdochona) hospeti Thapar, 1950 and Rhabdochona (Globochona) cf. chodukini Osmanov, 1957 in Tor putitora (Hamilton) (Cyprinidae, Cypriniformes); besides these, unidentifiable physalopterid larvae were recorded from M. armatus and T. putitora. Their detailed light and electron microscopical studies revealed some taxonomically important, previously not observed features and made possible their redescription. Fourth-stage larvae of P. (S.) bilaspurensis and R. (R.) turkestanica are described for the first time. The latter is resurrected as an independent species. The following are considered to be species inquirendae: a total of nine poorly described species of Rhabdochona Railliet, 1916 from T. putitora in Balochistan, Pakistan, all listed in the monograph of Kakar et al. (2011), plus an additional 15 species of the genus reported from cyprinids and a catfish in the same region (Balochistan) by the same authors. Also three congeneric species from India (R. nemacheili Rautela et Malhotra, 1982, R. putitora Kaur et Khera, 1991 and R. tori Gupta et Srivastava, 1982) and one from Pakistan (R. charsaddiensis Siddiqi et Khattak, 1984) should be considered as species inquirendae due to their poor descriptions. The names of Rhabdochona putitori Anjum, 2013, R. indusi Soofi, Birmani et Dharejo, 2017 and R. sindhicus Soofi, Birmani, Dharejo, Abbasi et Ghachal, 2020 are invalid according to the International Code of Zoological Nomenclature.

Recent examinations of some marine fishes from off the southern coast of Iraq revealed the presence of five species of Philometra Costa, 1845 (Nematoda: Philometridae): Philometra arabiensis sp. n. (males and females) from the ovary of the shrimp scad Alepes djedaba (Forsskål) (Carangidae, Carangiformes), Philometra psettoditis Moravec, Walter et Yuniar, 2012 (females) from the body cavity of the Indian halibut Psettodes erumei (Bloch et Schneider) (Psettodidae, Pleuronectiformes), Philometra terapontis Moravec, Gopalakrishnan, Rajkumar, Saravanakumar et Kaliyamoorthy, 2011 (female) from the ovary of the jarbua terapon Terapon jarbua (Forsskål) (Terapontidae, Centrarchiformes), Philometra sp. (females) from the ovary of the Arabian blackspot threadfin Polydactylus mullani (Hora) (Polynemidae, Carangariformes) and Philometra sp. 2 of Moravec et al. (2016a) (females) from the ovary and body cavity of the bartail flathead Platycephalus indicus (Linnaeus) (Platycephalidae, Perciformes). Philometra arabiensis sp. n. is mainly characterised by the length of spicules (198-243 µm) and gubernaculum (75-99 µm), the gubernaculum/spicule length ratio (1 : 2.33-2.79), the structure of the gubernaculum distal portion and the male caudal end, and the body length of males (1.86-2.73 mm). The present findings of P. psettoditis and P. terapontis in fishes of the Arabian Gulf represent new geographical records for these parasites.

Eudiplozoon nipponicum (Goto, 1891) Khotenovsky, 1985 (Monogenea: Diplozoidae), is known to parasitise Cyprinus carpio Linnaeus and species of Carassius. In this study, we conducted a taxonomic re-examination of E. nipponicum using genetic analysis and morphological comparisons from different host species from a single water system. rDNA nucleotide sequences of the internal transcription spacer 2 (ITS-2) region (645 bp) showed interspecific-level genetic differences among diplozoids from species of Carassius and C. carpio (p-distance: 3.1-4.0%) but no difference among those from different species of Carassius (0-0.4%) or between those from C. carpio collected in Asia and Europe (0-1.1%). Large variation was observed among 346 bp cytochrome c oxidase subunit I (COI) sequences (0.3-16.0 %); the topology of the phylogenetic tree showed no relationship to host genera or geographical regions of origin. Morphological observation showed that average clamp size of diplozoids from C. carpio was larger than those from Carassius spp. The number of folds on the hindbody was 10-25 for diplozoids from C. carpio and 12-19 for those from Carassius spp. Thus, our ITS-2 sequence and morphological comparison results indicate that diplozoids from C. carpio and species of Carassius belong to different species. The scientific name E. nipponicum should be applied to the species infected to the type host, Carassius sp. of Nakabo (2013) (Japanese name ginbuna). The diplozoid infecting C. carpio (Eurasian type) should be established as a new species: Eudiplozoon kamegaii sp. n. A neotype of E. nipponicum is designated in this report because the original E. nipponicum specimens are thought to have been lost.

In total 949 specimens of Trachinotus rhodopus (Gill) were collected over a 11-year period (from June 2013 to February 2024) from Acapulco Bay, Mexico. Parasite communities in T. rhodopus were quantified and analysed to explore two hypotheses related to their parasite species richness and diversity associated with the bentho-demersal and pelagic habits, and effects of the climatic fluctuations. Thirty-two metazoan parasite taxa/species were identified: three species of 'Monogenea', 14 Digenea, one Aspidogastrea, one Acanthocephala, two Cestoda, three Nematoda and eight Crustacea. The digeneans and copepods were the best represented groups. The component parasite communities were characterised by the numerical dominance of the acanthocephalan Rhadinorhynchus sp. Species richness (15-24 species) was similar to that reported for other species of carangid fish, but the richness of the digeneans was significantly higher. The parasite communities of T. rhodopus exhibited high variability in species composition, suggesting that each species of parasite may respond differently to environmental changes. However, the species richness and diversity were fairly stable over time. Climatic events of La Niña and El Niño probably generated notable changes in the structure of local food webs, thus indirectly influencing the transmission rates of several endoparasite species.

Abstract: In 1985, Amin presented a new system for the classification of the Acanthocephala in Crompton and Nickol's (1985) book 'Biology of the Acanthocephala' and recognized the concepts of Meyer (1931, 1932, 1933) and Van Cleave (1936, 1941, 1947, 1948, 1949, 1951, 1952). This system became the standard for the taxonomy of this group and remains so to date. Many changes have taken place and many new genera and species, as well as higher taxa, have been described since. An updated version of the 1985 scheme incorporating new concepts in molecular taxonomy, gene sequencing and phylogenetic studies is presented. The hierarchy has undergone a total face lift with Amin's (1987) addition of a new class, Polyacanthocephala (and a new order and family) to remove inconsistencies in the class Palaeacanthocephala. Amin and Ha (2008) added a third order (and a new family) to the Palaeacanthocephala, Heteramorphida, which combines features from the palaeacanthocephalan families Polymorphidae and Heteracanthocephalidae. Other families and subfamilies have been added but some have been eliminated, e.g. the three subfamilies of Arythmacanthidae: Arhythmacanthinae Yamaguti, 1935; Neoacanthocephaloidinae Golvan, 1960; and Paracanthocephaloidinae Golvan, 1969. Amin (1985) listed 22 families, 122 genera and 903 species (4, 4 and 14 families; 13, 28 and 81 genera; 167, 167 and 569 species in Archiacanthocephala, Eoacanthocephala and Palaeacanthocephala, respectively). The number of taxa listed in the present treatment is 26 families (18% increase), 157 genera (29%), and 1298 species (44%) (4, 4 and 16; 18, 29 and 106; 189, 255 and 845, in the same order), which also includes 1 family, 1 genus and 4 species in the class Polyacanthocephala Amin, 1987, and 3 genera and 5 species in the fossil family Zhijinitidae.

Our team's discovery of the link between chronic "latent" infection with Toxoplasma gondii (Nicolle et Manceaux, 1908) and suicidal behaviour, and our subsequent cross-diagnostic confirmatory work and mechanistic extensions, evolved from our neuroimmunology studies on affective and behavioural dysregulation exacerbated by allergic sensitisation and allergen exposure. Another root was studying behavioural changes and cytokine gene expression in the brain of rodents sensitised and exposed to aeroallergens. We "piggy-backed" our project funded to study coupling between aeroallergen sensitisation and exposure in patients with recurrent mood disorders, by measuring Toxoplasma gondii (T. gondii) antibodies in existing samples, and found associations between IgG serointensity and past suicide attempts. Successively, we then reported significant associations between T. gondii seropositivity and/or serointensity and suicidal behaviour in patients with schizophrenia in Germany, recent attempters in Sweden, and longitudinally in a cohort of Danish mothers. In the Danish mothers the exposure to T. gondii preceded self-directed harm and violent suicide attempts; the association was stronger with higher serointensity strata demonstrating a dose-effect. Furthermore, we identified links between T. gondii IgG and suicide endophenotypes of aggression and impulsivity in both individuals with no history of mental illness, and in patients with Intermittent Explosive Disorder (IED). We also found associations between T. gondii and risk factors of suicidal behaviour such as hopelessness and anhedonia in the Amish, depressive symptoms in pregnant women and women Veterans, frailty in older adults, and cognitive deficits in patients with bipolar disorder. Recently, we reported positive associations between T. gondii IgG serointensity with suicidal ideation, impulsivity, depression scores, and daytime dysfunction due to sleep problems in US Veterans who previously attempted suicide. Toxoplasma gondii emerged rather unexpectedly and then took over a considerable proportion of our neuroimmune research portfolio. It satisfied both intellectual appetites, and brought celebrations of discovery, with three systematic reviews and meta-analyses published to date, and a substantial majority of primary articles confirming our initial observations. Toxoplasma gondii also brought considerable frustrations, such as initial grant application setbacks, inability to completely demonstrate causality and, so far, prophylactic and therapeutic impotence for mental health applications in general. While we do not have, as of today, effective and safe treatments for chronic toxoplasmosis with demonstrated mental health benefits in immunocompetent hosts, there are reasons to be optimistic regarding future discoveries. These may include vaccines, novel medications using in silico exploration with biological confirmation, trials of reactivation prevention, as well as identification and targeting of mediating mechanisms. Yet the most justified reasons for optimism are the potential to apply machine learning (ML) and artificial intelligence (AI) methodologies to big data with

Here we describe the new trypanosomatid, Phytomonas borealis sp. n., from the midgut of the spiked shieldbugs, Picromerus bidens (Linnaeus), collected in two locations, Novgorod and Pskov Oblasts of Russia. The phylogenetic analyses, based on the 18S rRNA gene, demonstrated that this flagellate is a sister species to the secondary monoxenous Phytomonas nordicus Frolov et Malysheva, 1993, which was concurrently documented in the same host species in Pskov Oblast. Unlike P. nordicus, which can complete its development (including exit to haemolymph and penetration into salivary glands) in Picromerus bidens, the new species did not form any extraintestinal stages in the host. It also did not produce endomastigotes, indispensable for transmission in other Phytomonas spp. These observations, along with the fact that P. bidens overwinters at the egg stage, led us to the conclusion that the examined infections with P. borealis were non-specific. Strikingly, the flagellates from the Novgorod population contained prokaryotic endosymbionts, whereas the parasites from the second locality were endosymbiont-free. This is a first case documenting presence of intracellular symbiotic bacteria in Phytomonas spp. We suggest that this novel endosymbiotic association arose very recently and did not become obligate yet. Further investigation of P. borealis and its intracellular bacteria may shed light on the origin and early evolution of endosymbiosis in trypanosomatids.

Entamoeba moshkovskii Tshalaia, 1941 is prevalent in developing countries and it is considered to be primarily a free-living amoeba, which is morphologically indistinguishable, but biochemically and genetically different from the human infecting, pathogenic Entamoeba histolytica Schaudinn, 1903. The pathogenic potential of this organism is still under discussion. Entamoeba moshkovskii in human stool samples has been reported in different countries such as the United States, Italy, Australia, Iran, Turkey, Bangladesh, India (Pondicherry), Indonesia, Colombia, Malaysia, Tunisia, Tanzania and Brazil, but no data are available about the occurrence of E. moshkovskii in farm animals. This study provides data on the occurrence of E. moshkovskii in pigs in a total of 294 fresh faecal samples collected from five different regions in Kolkata, West Bengal, India. Stool samples were tested by nested PCR using primers targeting SSU rDNA of E. moshkovskii. The amplified PCR products were further confirmed by RFLP technique. Purified nested PCR products were also sequenced and identified via BLAST program run on the NCBI website to confirm species along with their genetic characteristics of the E. moshkovskii isolates. Overall 5.4 % samples were identified as E. moshkovskii positive. Results of this study demonstrate that swine can host E. moshkovskii and should be considered as a potential natural reservoir for E. moshkovskii. However, the occurrence of E. moshkovskii infection in pigs was not statistically associated with their faecal consistency, sex and developmental stage.

Some free-living amoebae are a potential threat to human health. The best known species are those of the genus Acanthamoeba Volkonsky, 1931, which cause Acanthamoeba keratitis, granulomatous amoebic encephalitis and other forms of tissue inflammation. The aim of the present study was to search for potential pathogenic genotypes of free-living amoeba in the sand in children's playgrounds. Our results confirmed that free-living amoebae were present in all examined playgrounds. Sequences of the 18S rDNA have shown that all isolated potentially pathogenic strains of amoebae belong to genotype T4 of Acanthamoeba. The potential pathogenicity of isolates was confirmed on mice. The presence of pathogenic amoebae in the examined sand may be a potential source of human infection.

Despite the global distribution of the brown dog tick, Rhipicephalus sanguineus (Latreille, 1806) sensu lato (s.l.), limited information exists about their identity from the Arabian Peninsula. Ticks from free roaming urban dogs and dromedary camels in Riyadh, Saudi Arabia were morphologically identified, confirmed with scanning electron microscopy and characterised at mitochondrial DNA (cox1, 12S rDNA and 16S rDNA). A total of 186 ticks were collected from 65 free roaming dogs (n = 73) and 84 dromedary camels (n = 113). Morphologically, 5.9% (11/186) were R. sanguineus s.l. and Hyalomma spp. (93.5%, 174/186). From within R. sanguineus s.l., the presence of Rhipicephalus cf. camicasi Morel, Mouchet et Rodhain, 1976 (1 dog, 2 camels) and Rhipicephalus turanicus Pomerantsev, 1936 (1 camel) is reported. The examined R. cf. camicasi form a sister group to R. sanguineus s.l. tropical lineage at all DNA markers. Dogs were parasitised by Hyalomma dromedarii Koch, 1844 (n = 59), Hyalomma impeltatum Schulze et Schlottke, 1930 (n = 1), Hyalomma excavatum Koch, 1844 (n = 2), Hyalomma turanicum Pomerantsev, 1946 (n = 1) and Hyalomma rufipes Koch,1844 (n = 1). DNA from dog blood (n = 53) from Riyadh confirmed a low prevalence of canine vector-borne pathogens that does not exceed 5.7% for Babesia spp., Mycoplasma spp., Anaplasma platys, Hepatozoon canis and Ehrlichia canis using multiplexed tandem PCR (MT-PCR) and diagnostic PCR. Low prevalence of R. sanguineus s.l. on dogs likely contributed to the low level of canine vector-borne pathogens in Saudi Arabia. We demonstrate that dogs in the central Arabian Peninsula are more commonly parasitised by Hyalomma spp. than R. sanguineus s.l.

Species of Acanthamoeba Volkonsky, 1931 are the commonest among free-living amoebae that are widespread in different water resources but with lacking phylogenetic data. This study aims at detecting molecular prevalence and genetic diversity of Acanthamoeba isolates in Kafrelsheikh Governorate, Egypt. Forty-eight water samples were collected from 12 swimming pools; four samples during each season over one year. Samples were filtered, cultivated on non-nutrient agar plates and examined microscopically. Polymerase chain reaction (PCR) and sequence analysis of positive samples targeting diagnostic fragment 3 (DF3) of the small subunit rRNA gene were done. Cultivation succeeded to detect 14 (29%) positive samples while PCR missed three positive samples. The obtained sequences were phylogenetically analysed. The phylogenetic tree was constructed for them with sequences of reference species from the NCBI database. The identified species were Acanthamoeba castellanii Douglas, 1930 (T4), A. astronyxis (Ray et Hayes, 1954) (T9) and A. hatchetti Sawyer, Visvesvara et Harke, 1977 (T11). The prevalence of species of Acanthamoeba was higher during summer and fall. Therefore, the control of the presence of Acanthmoeba spp. in swimming pools needs immediate, effective and practical measures to prevent and control infection with species of Acanthamoeba.

Dactylogyrus Diesing, 1850 is the most species-rich genus in Platyhelminthes, with over 900 documented species, that are mostly strictly specific to freshwater cyprinoids. The morphological Dactylogyrus groups afrobarbae-type, carpathicus-type, pseudoanchoratus-type, and varicorhini-type are known to occur in Africa. This study describes a new species of Dactylogyrus of the varicorhini-type from the gills of the endemic smallmouth yellowfish Labeobarbus aeneus (Burchell) from the Vaal River, Free State Province, South Africa. Dactylogyrus matlopong sp. n. is unique among its varicorhini-type congeners mainly by the accessory piece of the male copulatory complex that presents a hook-shaped subunit with defined round base not reaching the male copulatory organ, combined with the presence of a conspicuous medial projection on the anterior margin of the ventral bar. Sequences of the partial 28S and 18S rRNA genes, together with entire ITS1 region, were generated for the first time for a species of Dactylogyrus from South Africa. Concatenated phylogenetic analyses of selected Dactylogyrus spp. showed that these parasites group according to their morphological types.

Tapeworms of the genus Caryophyllaeus Gmelin, 1790 (Caryophyllidea: Caryophyllaeidae), common parasites of cyprinid fishes, are reviewed and taxonomic status of 42 nominal taxa that have been placed in the genus during its long history is clarified. The following seven species occurring in the Palaearctic Region are recognised as valid: C. laticeps (Pallas, 1781), C. auriculatus (Kulakovskaya, 1961), C. balticus (Szidat, 1941) comb. n. (syn. Khawia baltica Szidat, 1941), C. brachycollis Janiszewska, 1953, C. fimbriceps Annenkova-Chlopina, 1919, C. syrdarjensis Skrjabin, 1913, and newly described Caryophyllaeus chondrostomi sp. n. (= C. laticeps morphotype 4 of Bazsalovicsová et al., 2014) from common nase, Chondrostoma nasus (Linnaeus), found in Austria and Slovakia. The new species differs by the paramuscular or cortical position of preovarian vitelline follicles, a large, robust body (up to 64 mm long), conspicuously long vas deferens, flabellate scolex with small wrinkles on the anterior margin, and anteriormost testes located in a relatively short distance from the anterior extremity. Caryophyllaeus kashmirenses Mehra, 1930 and Caryophyllaeus prussicus (Szidat, 1937) comb. n. are considered to be species inquirendae, C. truncatus von Siebold in Baird, 1853 and C. tuba von Siebold in Baird, 1853 are nomina nuda. Data on the morphology, host spectra, distribution and known life-cycles of valid species are provided. Phylogenetic interrelations of four species of the genus including its type species and newly described C. chondrostomi were assessed based on an analysis of sequences of lsrDNA and cox1. A key to identification of all valid species of Caryophyllaeus is also provided.

In an effort to expand knowledge of Clade 3-one of the ten clades that compose the non-monophyletic order 'Tetraphyllidea' all current members of which parasitise orectolobiform sharks-we targeted species of orectolobiform sharks that had not previously been examined for 'tetraphyllidean' cestodes. That work led to the discovery of three new species off Australia and Taiwan. Ambitalveolus gen. n. was erected to accommodate these species. Ambitalveolus costelloae gen. n. et sp. n., Ambitalveolus kempi sp. n., and Ambitalveolus penghuensis sp. n. differ from one another in scolex size, genital pore position, and number of marginal loculi, proglottids, and testes. Among 'tetraphyllideans', the new genus most closely resembles the two other genera in Clade 3. It differs from Carpobothrium Shipley et Hornell, 1906 in lacking anterior and posterior flap-like extensions of its bothridia; instead, its bothridia are essentially circular. It differs from Caulopatera Cutmore, Bennett et Cribb, 2010 in that its vitelline follicles are in two lateral bands, rather than circum-medullary, and in that its bothridia bear, rather than lack, conspicuous marginal loculi. A key to the three genera in Clade 3 is provided. A phylogenetic analysis including new sequence data for one of the three new species of Ambitalveolus gen. n., the only species of Caulopatera, and all four described species and one undescribed species of Carpobothrium supports previously hypothesised close affinities between Caulopatera and Carpobothrium, with the new genus as their sister group. This is the first report of 'tetraphyllidean' cestodes from the orectolobiform shark family Brachaeluridae Applegate. The association of the new species with orectolobiform sharks is consistent with those of the other members of Clade 3. However, whereas species of Carpobothrium and Caulopatera parasitise members of the hemiscylliid genus Chiloscyllium Müller et Henle, species of Amitalveolus gen. n. parasitise members of the Brachaeluridae and Orectolobidae Gill.

While the identification of adult monogeneans primarily relies on morphological criteria, the morphology of a number of monogenean larvae (oncomiracidia) is to this day scarcely described. Yet, oncomiracidium plays a crucial role in the life cycle of the parasite, being responsible for the detection and localisation of its host, as well as for its attachment to this host. Few studies investigated the external morphological structures related to these functions, especially in Monopisthocotylea. The present study focuses on the early life stages (egg and oncomiracidium) of Lamellodiscus erythrini Euzet et Oliver, 1967, which are accurately described for the first time by light and scanning electron microscopy. Eggs of L. erythrini are smooth, tetrahedral and extended by a long polar filament. Freshly laid, the egg is brown, opaque, impermeable and becomes transparent as it matures, revealing the larva and its eye spots. When the egg matures, the egg casing exhibits functional weak points all around the operculum through which the larva emerges. The larva of L. erythrini is elongated, cylindrical and has a highly developed ciliation covering three areas: an anterior zone, a pleural zone, and a posterior cone. The ciliated cells are contiguous and are organised in a structured mosaic of spherical droplets, each cilium inserted into one. The larval tegument presents microvilli as well as 9 pairs of dorsal sensilla. The haptor is a closed structure consisting of 14 sclerotised hooklets, 12 arranged in a circle, and one pair positioned at the centre of the haptor. The possible link between these morphological structures and larval behaviour is discussed.

Southern Africa is considered one of the world's 'hotspots' for the diversity of cartilaginous fishes (Chondrichthyes), with currently 204 reported species. Although numerous literature records and treatises on chondrichthyan fishes are available, a paucity of information exists on the biodiversity of their parasites. Chondrichthyan fishes are parasitised by several groups of protozoan and metazoan organisms that live either permanently or temporarily on and within their hosts. Reports of parasites infecting elasmobranchs and holocephalans in South Africa are sparse and information on most parasitic groups is fragmentary or entirely lacking. Parasitic copepods constitute the best-studied group with currently 70 described species (excluding undescribed species or nomina nuda) from chondrichthyans. Given the large number of chondrichthyan species present in southern Africa, it is expected that only a mere fraction of the parasite diversity has been discovered to date and numerous species await discovery and description. This review summarises information on all groups of parasites of chondrichthyan hosts and demonstrates the current knowledge of chondrichthyan parasites in South Africa. Checklists are provided displaying the host-parasite and parasite-host data known to date.

Morphological data are used to describe a new nematode species, Heterocheilus floridensis sp. n. (Heterocheilidae) from the digestive tract of the Florida manatee Trichechus manatus latirostris (Harlan) (Trichechidae, Sirenia) from Florida, USA. Examination by light and scanning electron microscopy revealed that the new species differs from the related Heterocheilus tunicatus Diesing, 1839 mainly by having dentigerous ridges on the inner surface of the lips, a median unpaired papilla located anterior to the cloaca, and a considerably larger body size. Sequence data for subunits I and II of mitochondrial cytochrome oxidase gene, 18S small subunit and 28S ribosomal RNA genes were provided for molecular characterisation of the new species. However, the current unavailability of homologous sequence data for congeneric specimens precluded a molecular assessment of the morphological species hypothesis, and ascaridoid phylogenetic hypotheses could not be advanced. Specimens of Heterocheilus sp. collected from the Antillean manatee Trichechus manatus manatus Linnaeus in Puerto Rico, on loan from the US National Museum of Natural History, were morphologically consistent with the new species, so apparently all congeneric nematodes reported from both subspecies of the West Indian manatee Trichechus manatus Linnaeus and previously identified as H. tunicatus belong rather to H. floridensis sp. n. Heterocheilus hagenbecki (Khalil et Vogelsang, 1932) Sprent 1980 is here considered to be a species inquirenda. A key to valid species of Heterocheilus Diesing, 1839 is provided.

Tapeworms of the genus Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidae) are common and widespread intestinal parasites of whitefish (Coregonus spp., Salmonidae: Coregoninae). Previous taxonomic studies, based solely on morphology and inconsistently fixed specimens, concluded that all salmoniform fish, including whitefish, are parasitised by a single euryxenous and highly polymorphic species, Proteocephalus longicollis (Zeder, 1800). However, recent molecular phylogenetic analyses have revealed the existence of several species specific to individual genera or even species of salmoniform fish. In this study, Proteocephalus fallax La Rue, 1911 is redescribed based on newly collected and genetically characterised specimens from several Coregonus species in Switzerland, the type locality of the species, and in Norway. This cestode was previously synonymised with P. exiguus La Rue, 1911, a parasite of whitefish in North America, but the two species are not closely related. Proteocephalus fallax differs from P. exiguus in its larger body size, wider proglottids, shorter cirrus sac and broader scolex. In addition, the other Proteocephalus species described in whitefish are briefly discussed, with comments on their validity, host range and distribution.

Blood-sucking arthropods belonging to the order Diptera, encompassing mosquitoes, sandflies, midges, blackflies, horseflies and tsetseflies serve as vectors for a myriad of pathogens, inflicting substantial harm on both human and animal health globally. The analysis and visualisation of global hotspots and trends pertaining to vector-borne diseases, stemming from these six categories of arthropods, constituted a reliable reference for further delving into the research on Diptera insect vectors. To achieve this, we mined literature information from the Web of Science Core Collection (WoSCC), encompassing all publications related to these six arthropod groups, and leveraged VOSviewer software for bibliometric analysis and visualisation. This resulted in the construction of comprehensive relationship networks encompassing keywords, countries, institutions and authors. A comprehensive analysis encompassed 41,393 research publications, segmented into 34,363 studies on mosquitoes, 1,668 on sandflies, 3,665 on midges, 241 on blackflies, 336 on horseflies and 1,120 on tsetseflies. The bibliometric analysis, coupled with visual characterisation, offered a multifaceted synthesis of the gathered data from diverse angles. The scientometric analysis quantitatively assessed and identified the contributions of keywords, countries, institutions and authors pertaining to the research of each vector. The resulting visualisation knowledge maps elucidate collaborative network relationships within the respective vector research domains. This research endeavour stems from numerous driving forces, and a comprehensive grasp of its future trajectories and research hotspots can empower scientists with historical perspectives and forward-looking insights, fostering the formulation of innovative and impactful research ideas for the years ahead.

Examinations of nematodes collected from some marine fishes off the southwestern coast of Java, Indonesia in 2000 and 2001 revealed the presence of the following six species: ascaridoids Ichthyascaris grandis sp. n. from the intestine of Lophiomus setigerus (Vahl), I. cf. longispicula Li, Liu, Liu et Zhang, 2012 from the intestine of Conger cinereus Rüppel, Ichthyascaris sp. from the body cavity of Lobotes surinamensis (Bloch), and Raphidascaroides halieutaeae Yin, 1983 from the intestine of Halieutaea stellata (Vahl), and philometrids Philometra ivaschkini Parukhin, 1976 from the stomach wall of Trichiurus lepturus Linnaeus and P. psettoditis Moravec, Walter et Yuniar, 2012 from the body cavity (liver) of Psettodes erumei (Bloch et Schneider). Descriptions of these nematodes based on light and scanning electron microscopical studies are provided. The new species I. grandis sp. n. is mainly characterised by large body measurements (males and females up to 41.8 mm and 73.6 mm long, respectively), the length of spicules (0.99-1.05 mm), the tail tip usually without rudimentary spines and by the presence of 44-53 pairs of caudal papillae, eight to twelve of which being postanals. In addition to new data on the morphology of R. halieutaeae and other nematodes recorded, the 11 species of Raphidascaroides Yamaguti, 1941 poorly described from marine fishes in South Asia and reviewed in the monograph of Sood (2017) are considered species inquirendae and incertae sedis.

The nematode Spinitectus notopteri Karve et Naik, 1951 was collected from two species of freshwater fish belonging to the family Notopteridae, namely Chitala ornata (Gray) and Notopterus notopterus (Pallas), at Khun Thale Swamp in Surat Thani province of southern Thailand. The overall prevalence of the parasite was found to be 88% (94 fish infected/106 fish examined). A higher prevalence was found in C. ornata (96%), while a higher intensity was noted for N. notopterus (117 parasites/fish). The most important morphological characters were the presence of cephalic and cuticular structures, precloacal ridges, and genital papillae. Specimens were genetically characterised using cox1 mtDNA. Morphological characteristics were most similar to Spinitectus petterae Boomker, 1993 from Clarias gariepinus (Burchell) in Africa, while the genetic data were dissimilar to all available data for the genus. Therefore, the identification of nematode specimens using a combination of morphological and molecular techniques is stressed. This study also presents the first molecular analysis of S. notopteri infecting Thai freshwater fish and a new geographical record for S. notopteri.

The pathogenicity of haemogregarines and their effects on the health status of ectothermic hosts remain largely unexplored. In this study, we examined the impact of Hemolivia mauritanica (Sergent et Sergent, 1904) infection on the differential leukocyte count (DLC) as a measurable indicator of health in tortoise hosts. A total of 206 blood smears were analysed, including 181 from spur-thighed tortoises (Testudo graeca Linnaeus) and 25 from marginated tortoises (Testudo marginata Schoepff). Light microscopy was used to identify infected individuals, determine DLC, and quantify parasitaemia levels. Overall, H. mauritanica was detected in 125 of 181 (69%) T. graeca samples and 21 of 25 (84%) T. marginata samples. To assess whether infection influenced DLC, we statistically compared leukocyte profiles between infected and uninfected individuals. Additionally, we evaluated the effects of other factors, including host species, parasitaemia intensity, sex, age, and the month and year of blood collection. Wilcoxon rank-sum tests revealed that parasitaemia and age had a statistically significant effect on DLC in T. graeca. Further analysis using linear models showed a significant association between parasitaemia and DLC, specifically affecting azurophils in T. graeca and basophils in T. marginata. Nine T. graeca tortoises positive for H. mauritanica were co-infected with haemosporidian parasites of the genus Haemocystidium Castellani et Willey, 1904, specifically three with Haemocystidium anatolicum (Orkun et Güven, 2013) and six with Haemocystidium caucasicum (Krasilnikov, 1965). Although co-infection itself was not statistically significant, a separate analysis of Haemocystidium parasitaemia revealed a significant effect on lymphocyte DLC. Furthermore, the frequent presence of mitotic and polychromatophilous erythrocytes in H. mauritanica-infected tortoises suggests a potential increase in erythrocyte regeneration.