Systematic Parasitology最新文献

{"title":"The description of Metacanthocephalus (Bimuscularis) rennicki inflatus n. subgen., n. subsp. (Acanthocephala: Leptorhynchoididae) from Notothenia coriiceps off Galindez Island, West Antarctica, with the erection of two new subgenera and subspecies.","authors":"Omar M Amin, Anshu Chaudhary, Makoto Enoki Caracciolo, Nataliya Yu Rubtsova, Hridaya S Singh, Wanderley de Souza","doi":"10.1007/s11230-025-10262-8","DOIUrl":"10.1007/s11230-025-10262-8","url":null,"abstract":"<p><p>The study of many acanthocephalans of the genus Metacanthocephalus Yamaguti, 1959 (Leptorhynchoididae) from the black rockcod Notothenia coriiceps Richardson in the Argentine Islands revealed their close affiliation to Metacanthocephalus rennicki (Leiper and Atkinson, 1914, 1915). Metacanthocephalus rennicki was originally described from the emerald rockcod Trematomus bernacchii Boulenger in Cape Evans, Ross's Sea, McMurdo Sound, and is herein split into two subspecies in two different primary fish host species and separate geographical locations. These specimens are herein described as Metacanthocephalus rennicki inflatus n. subsp. which is similar to the traditional Metacanthocephalus rennicki rennicki n. subsp. by having similar eggs (with polar prolongation of fertilization membrane) of the same size (75-93 X 20-25), ellipsoid proboscis with 5-7 hooks per row, and subterminal gonopore in both sexes. Specimens of M. rennicki inflatus from N. coriiceps off Galindez Island, Argentine Islands are, however, distinguished from those of M. rennicki rennicki n. subsp. from a different host, T. bernacchii, in McMurdo Sound by having markedly wider measurements of their fusiform trunk, elliptoid proboscides, and more rows of proboscis hooks (14-16) compared to the subcylindrical trunk and cylindrical proboscis with 12-13 (usually 12) hook rows of M. rennicki rennicki. In addition, the cephalic ganglion of specimens of M. rennicki inflatus is found at or just posterior to the middle of the proboscis receptacle, compared to being in the anterior half of the receptacle as in M. rennicki rennicki. Specimens of both subspecies are clearly distinguished from the 3 other species of Metacanthocephalus by characters of size and shape of trunk, proboscis size and armature, egg size, and position of cephalic ganglion and of the female and male gonopore. We regard all species to be independently valid as originally described. We have also included the two subspecies of M. rennicki with the 3 other species of Antarctic Metacanthocephalus (M. campbelli Leiper and Atkinson, 1914, 1915, M. dalmori Zdzitowiecki, 1983; M. johnstoni Zdzitowiecki, 1983) in a new subgenus Bimuscularis n. subgen (with 2 muscular sphincters). The other subgenus, Unimuscularis n. subgen. includes the two other Japanese species, M. ovicephalus (Zhukov, 1960) and M. pleuronichthydis Yamaguti, 1959, that have only one sphincter. We now also provide the first molecular analysis of a species of Antarctic Metacanthocephalus, M. (B.) rennicki inflatus n. subgen., n. subsp. The molecular characterization of the nuclear gene 18S of the ribosomal subunit and cox1 of the mitochondrial gene of Metacanthocephalus, M. (B.) rennicki inflatus n. subgen., n. subsp is provided. Furthermore, in regard to the phylogenetic relationships of the genus Metacanthocephalus and the other genera of Echinorhynchida, phylogenetic analyses were performed using maximum likelihood (ML) and Bayesian inference (BI). The ","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"103 1","pages":"4"},"PeriodicalIF":1.2,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145991685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Description of Pseudobenedenia galindezensis sp. n. (Monopisthocotyla: Capsalidae) from the skin of Notothenia coriiceps off the coastal waters of Galindez Island, West Antarctica.","authors":"Nataliya Y Rubtsova, Anshu Chaudhary, Sergiy Glotov, Tetiana A Kuzmina","doi":"10.1007/s11230-025-10261-9","DOIUrl":"10.1007/s11230-025-10261-9","url":null,"abstract":"<p><p>A new species of monopisthocotylan parasite has been identified on the body surface of the Antarctic rockcod Notothenia coriiceps Richardson, in the coastal waters surrounding Galindez Island, West Antarctica. The newly described species, Pseudobenedenia galindezensis sp. n., is morphologically distinct from all previously recognized species within the genus Pseudobenedenia as evidenced by a combination of unique morphometric traits. These include the shape and size of opisthaptoral sclerotized elements, the presence of a particularly robust accessory sclerite, and a characteristic ratio between the anterior hamulus and accessory sclerite. These features collectively support its recognition as a separate species. A well-developed orifice of the common genital opening was observed and measured in the newly described species, an anatomical feature not previously documented in Pseudobenedenia. Measurements of the vagina are provided for the first time for all of the described Pseudobenedenia species. The presence or absence of a distinct gap between the testes represents a novel diagnostic character introduced in this description. Additional distinguishing features include the length-to-width ratios of the testes and body, as well as the body length-to-opisthaptor length ratio, all of which further support the species' distinctiveness. Molecular analyses of 18S and 28S nuclear markers were conducted to study the phylogenetic position of this new species within the family Capsalidae. The results indicated consistent genetic divergences, which were accompanied by observed morphological differences, thereby substantiating the classification of the species as new to science. Molecular analysis was conducted to differentiate P. galindezensis sp. n. from the closely related Pseudobenedenia coriicepsi. This new species was found on a fish host that is morphologically distinct from most collected N. coriiceps, characterized by its larger size and reddish color; its identity was confirmed using mitochondrial cox1 sequences. A significant finding of our study is that one nototheniid species can host more than one species of Pseudobenedenia.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"103 1","pages":"1"},"PeriodicalIF":1.2,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145991712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accacoeliid trematodes in two sunfish species, Masturus lanceolatus and Mola mola, in Japanese waters.","authors":"Tsukasa Waki, Hikaru Nakano, Toshiyuki Okawa, Takanori Ishikawa","doi":"10.1007/s11230-025-10259-3","DOIUrl":"10.1007/s11230-025-10259-3","url":null,"abstract":"<p><p>Trematodes of the family Accacoeliidae Odhner, 1911 are well known as parasites of sunfishes. Herein, we report the accacoeliid trematode fauna of two sunfish species, Mola mola (Linnaeus) and Masturus lanceolatus (Liénard), in Japanese waters. Between 2023 and 2025, four individuals of each host species were examined, yielding 497 trematodes. These trematodes specimens were assigned to ten accacoeliid species (497 individuals in total) belonging to five genera through morphological and molecular analyses based on partial sequences of the nuclear 28S ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes. Four of the ten species were identified as new to science: Accacladocoelium latens n. sp., Accacladocoelium mayosenase n. sp., Accacladocoelium mica n. sp., and Rhynchopharynx yarimanbou n. sp. Detailed morphological descriptions were also provided for six known species: Accacladium serpentulum Odhner, 1928; Accacoelium contortum (Rudolphi, 1819); Accacladocoelium nigroflavum (Rudolphi, 1819); Accacladocoelium petasiporum Odhner, 1928; Odhnerium calyptrocotyle (Monticelli, 1893); and Rhynchopharynx paradoxa Odhner, 1928. Furthermore, Accacladocoelium alveolatum Robinson, 1934 was synonymized with Accacladocoelium nigroflavum based on molecular and morphological evidence.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"103 1","pages":"2"},"PeriodicalIF":1.2,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145991707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New species of the genus Skrjabinolecithum (Digenea: Haploporidae) from the mullets in Russia, the Far East, and Vietnam: morphology and molecular data.","authors":"Dmitry Atopkin, Alina Beloded Vladimir Besprozvannykh","doi":"10.1007/s11230-025-10260-w","DOIUrl":"10.1007/s11230-025-10260-w","url":null,"abstract":"<p><p>The type species of the trematode genus Skrjabinolecithum, S. spasskii, a parasite of mullets in the Russian Far East and Vietnam, was shown to possess three different variants of rDNA sequences in earlier studies. The goal of the present study is to clarify the taxonomic status of genetically different trematodes, considered S. spasskii, in the Russian Far East and Vietnam by means of new morphological and molecular data. For this study, trematodes of the genus Skrjabinolecithum were collected from mugilid fish from estuaries of rivers of the south of the Russian Far East and the Cat Ba Island, Vietnam. Preliminary species identification and detailed morphometric analysis were carried out using high-resolution light microscopy. Molecular differentiation and phylogenetic analyses were carried out based on nuclear 28S rDNA and mitochondrial cox1 gene sequences. As a result, two morphotypes of S. spasskii were revealed, and two new species, S. kievkaense n. sp. and S. vietnamense n. sp., were validated. These species have no qualitative differences in body form and in organ structure and arrangements but have some differences in metric parameters. The validity of the new species was confirmed by phylogenetic analysis based on the mitochondrial cox1 gene sequence dataset.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"103 1","pages":"3"},"PeriodicalIF":1.2,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145991714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Description of a new species of Ixodes Latreille, 1795 (Acari: Ixodidae), parasite of the checkered elephant shrew, Rhynchocyon cirnei Peters (Macroscelidea: Macroscelididae) in Zambia.","authors":"Dmitry A Apanaskevich, Madison D Hall","doi":"10.1007/s11230-025-10258-4","DOIUrl":"https://doi.org/10.1007/s11230-025-10258-4","url":null,"abstract":"<p><p>Ixodes (Afrixodes) colboi n. sp. (Acari: Ixodidae) is described based on females ex the checkered elephant shrew, Rhynchocyon cirnei Peters (Macroscelidea: Macroscelididae) from Zambia. Females of this new species can be distinguished from other Afrotropical species of the subgenus Afrixodes Morel, 1966 by the development of carinae and scutal punctations, shape of apron and anterior projection of basis capituli, length and development of spurs on palpal segment I, coxae and trochanters, and the size and development of the syncoxae.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"102 6","pages":"62"},"PeriodicalIF":1.2,"publicationDate":"2025-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145472302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new Phanerothecium (Monopisthocotyla, Oogyrodactylidae) species parasitizing Hypostomus strigaticeps (Siluriformes, Loricariidae) in the Pardo River, Southeastern Brazil.","authors":"Rafael Augusto Pereira da Silva, Julio Cesar Cenci de Aguiar, Mariana Bertholdi Ebert, Reinaldo José da Silva","doi":"10.1007/s11230-025-10257-5","DOIUrl":"10.1007/s11230-025-10257-5","url":null,"abstract":"<p><p>Phanerothecium acutum sp. n., the eighth described species of the genus Phanerothecium, is characterized by a unique combination of morphological and molecular traits. Morphologically, it differs from closely related species such as P. spinatus, P. deiropedeum, and P. macrosomum by features of the male copulatory organ (MCO), anchor configuration, and ventral bar structure. Notably, P. acutum sp. n. possesses an MCO armed with delicate spines, robust and truncated anchors with a slight elevation on the shaft, and a ventral bar with expanded extremities. Molecular analyses yielded three new 18S and two partial 28S rDNA sequences. A newly developed primer (DAC18F2) markedly improved PCR success and sequencing quality for 18S amplification. Genetic distance analyses based on 18S support P. acutum sp. n. as a distinct species, with interspecific divergence from most congeners ranging from 1.4-2.0%, and intraspecific variation of 0.0-0.2%. However, its genetic similarity to Phanerothecium sp. KX981456 (0.2-0.9%) highlights the need for additional data to clarify species boundaries. Phylogenetic reconstructions based on 18S and 28S confirmed the monophyly of Phanerothecium, placed within a strongly supported clade alongside viviparous gyrodactylideans, and reaffirmed the validity of the family Oogyrodactylidae. These findings underscore the importance of integrative approaches for resolving taxonomic relationships and suggest that the genus Phanerothecium, particularly among loricariid hosts, harbors greater diversity than currently recognized.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"102 6","pages":"61"},"PeriodicalIF":1.2,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145439856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new species of Parapleurocryptella Bourdon, 1972 (Isopoda: Bopyridae) from deep water squat lobster hosts of New Zealand with description of larval stages and transfer of the genus to Pleurocryptellinae.","authors":"Grace Kokasko, Jason D Williams, Christopher B Boyko, Kareen E Schnabel","doi":"10.1007/s11230-025-10255-7","DOIUrl":"10.1007/s11230-025-10255-7","url":null,"abstract":"<p><p>Squat lobsters (Decapoda: Anomura) harbor a high diversity of symbionts, including many parasitic isopod species (Epicaridea: Bopyridae) that reside in their branchial chambers. We describe the bopyrid Parapleurocryptella poha n. sp., found infesting at least four species of squat lobsters from New Zealand. The new species displays morphological traits characteristic of the genus Parapleurocryptella Bourdon, 1972 but it is distinct from the two other described species, P. minuta Bourdon, 1972 and P. elasmonoti Bourdon, 1972, based on the form of the female head as well as male antennal segmentation, midventral tubercles, and dactyl size. Additionally, the new species is widely separated geographically and occurs on different host species compared to others in the genus. The morphology of mature male and female specimens is described, and we show a significant positive correlation of mature female parasite length with host size. The first description of the epicaridium larva of any species of Parapleurocryptella is provided and illustrated using SEM. Epicaridium larvae of the new species possess posterior external yolk sacs, a feature previously reported for larvae in only two other bopyrid genera: Pleurocryptella Bonnier, 1900 and Paragigantione Barnard, 1920. A discussion of the potential impacts of this structure to our understanding of bopyrid life cycles is provided. Additionally, the genera Pleurocryptina Nierstrasz & Brender à Brandis, 1929 and Pagurocryptella Boyko & Williams, 2010 are transferred to Pleurocryptellinae from Pseudioninae and Pseudione kossmanni is transferred to Pleurocryptella as Pleurocryptella kossmanni (Nierstrasz and Brender à Brendis, 1923) nov. comb. based on examination of the holotype.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"102 6","pages":"60"},"PeriodicalIF":1.2,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12586414/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145439974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The complete mitochondrial genome of Plagiorchiidae gen. (Digenea, Plagiorchiidae) cercariae larvae in snails and its phylogenetic implications.","authors":"Janelle Laura J Gacad, Natalia I Yurlova, Maria Camille M Calilung, Mudjekeewis D Santos, Misako Urabe","doi":"10.1007/s11230-025-10253-9","DOIUrl":"10.1007/s11230-025-10253-9","url":null,"abstract":"<p><p>We determined the complete mitochondrial (mt) genome of a species of Plagiorchiidae, obtained from Lymnaea stagnalis snail collected at Lake Chany, western Siberia. The cercariae were morphologically close to Opisthioglyphe ranae (Frölich, 1791), but the species identification is still pending. The mitogenome is 13,849 base pairs in length. This genome includes 12 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and one non-coding region. Notably, 20 tRNA genes produce transcribed products with conventional cloverleaf structures, while two tRNA genes have unpaired D-arms. The gene atp8 is absent, and the remaining genes are transcribed in the same direction. The A + T content of the Plagiorchiidae gen. mt genome is 65.64%. The complete mtDNA of Plagiorchiidae gen. is shorter than that of all other related xiphidiate species compared in this study. Phylogenetic analysis based on the whole mitogenome revealed that Plagiorchiidae gen. clusters closely with species from the genera Plagiorchis and Glypthelmins. Additionally, the analysis of the 28S rRNA gene indicated that it belongs to Plagiorchiidae and is particularly close to Dolichosaccus (syn. Lecithopyge). This study reports the complete mitochondrial genome of Plagiorchiidae gen., providing a valuable resource of molecular markers for future research on the taxonomy, population genetics, and systematics of the family Plagiorchiidae.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"102 6","pages":"59"},"PeriodicalIF":1.2,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145294407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new species of Rondonia Travassos, 1920 (Nematoda: Atractidae) parasite of Metynnis lippincottianus (Cope) (Characiformes: Serrasalmidae) with an amended diagnosis of the genus, based on integrative analyses.","authors":"Chloe Barbosa, Mariana Bertholdi Ebert, Reinaldo José da Silva","doi":"10.1007/s11230-025-10254-8","DOIUrl":"10.1007/s11230-025-10254-8","url":null,"abstract":"<p><p>The genus Rondonia Travassos, 1920 comprises nematodes parasitizing teleost fishes and amphibians, but its taxonomic boundaries have long been uncertain due to limited morphological descriptions and lack of molecular data. Here, we provide an integrative taxonomic revision of Rondonia, combining light and scanning electron microscopy with molecular analyses of SSU and LSU rDNA sequences. A new species, Rondonia pardensis n. sp., is described from the intestine of Metynnis lippincottianus (Cope) (Characiformes: Serrasalmidae) in the Pardo River, Paranapanema River basin, Brazil. The new species is distinguished by the presence of a pre-bulbar excretory pore with a protruding teardrop-shaped structure covering it, the number and organization of the cloacal papillae (two pairs pre-cloacal, two pairs ad-cloacal and six pairs post-cloacal), the mouth with three bilobed lips bearing double papillae on each side arranged radially and two amphids, and a larger body size in comparison to its congeners. Phylogenetic analyses confirm its placement within Atractidae and support the monophyly of Rondonia. Based on morphological and molecular evidence, we propose a new taxonomic combination for specimens analysed by Cavalcante et al. (2016), herein reassigned as Rondonia xapuriensis nom. nov. We also examined the type material of Rondonia rondoni deposited by Travassos (1920) using SEM, confirming diagnostic features and recording additional characters that contribute to an updated morphological characterization of the species. In light of these findings, we propose an amended generic diagnosis for Rondonia that reflects its phylogenetic coherence and morphological consistency, and also a key for the identification of the Rondonia species. This study expands the known diversity of the genus, clarifies historical taxonomic uncertainties, and emphasizes the importance of integrative approaches for resolving the systematics of Atractidae.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"102 6","pages":"58"},"PeriodicalIF":1.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145234211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Pygocentrus nattereri and Serralsamus rhombeus (Characiformes: Serrasalmidae) from the State of Maranhão, Brazil, with the description of a new species of Anacanthorus.","authors":"Germán Augusto Murrieta Morey, Carmen Patricia Pasquel Pinedo, Ricardo Sousa Oliveira, Thais Avelar Vieira, Luciano Alfredo Rodriguez Chu, Alana Lislea de Sousa, Diego Carvalho Viana","doi":"10.1007/s11230-025-10252-w","DOIUrl":"10.1007/s11230-025-10252-w","url":null,"abstract":"<p><p>The present study aimed to report monogenoids parasitizing the gills of two species of piranhas from the state of Maranhão, Brazil: Pygocentrus nattereri Kner, and Serrasalmus rhombeus (Linnaeus). Fifty specimens of P. nattereri were caught in the Lake \"Grande\" in the municipality of São Bento, and 50 specimens of S. rhombeus were caught in the main channel of the Pericumã River, municipality of Pinheiro. Fourteen species of dactylogyrids were found parasitizing the gills of P. nattereri and S. rhombeus. Of the 14 species identified, 11 were found in P. nattereri: Amphitecium calycinum Boeger & Kritsky, 1988, Amphitecium camelum Boeger & Kritsky, 1988; Amphitecium falcatum Boeger & Kritsky, 1988; Amphitecium junki Boeger & Kritsky, 1988; Amphithecium sp.; Anacanthorus sp. 1; Anacanthorus jegui Van Every & Kritsky, 1992; Anacanthorus mesocondylus Van Every & Kritsky, 1992; Anacanthorus reginae Boeger & Kritsky, 1988; Anacanthorus sciponophallus Van Every & Kritsky, 1992 and Anacanthorus thatcheri Boeger & Kritsky, 1992. Five species were found in S. rhombeus: Am. calycinum; Am. falcatum; Anacanthorus amazonicus Van Every & Kritsky, 1992; A. maranhensis n. sp. and Notozothecium sp. Anacanthorus sp. 1 differs from its congeners by the morphology of the MCO, which is a flat tube with sclerotized walls and pointed terminations at both ends. Anacanthorus maranhensis n. sp. differs from its congeners by the morphology of the MCO, which is a trough-shaped tube. This study increases the number of reported dactylogyrids from P. nattereri to 28, and to 26 for S. rhombeus.</p>","PeriodicalId":54436,"journal":{"name":"Systematic Parasitology","volume":"102 6","pages":"57"},"PeriodicalIF":1.2,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145187668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}