Feather mites (Acariformes: Astigmata) are commonly regarded as harmless ectosymbionts of birds. In some cases, however, they may cause pathological conditions in their hosts. A new species of feather mite, Fainalges irritans sp. nov., is described from green-and-red macaws, Ara chloropterus Gray (Psittaciformes: Psittacidae) in Brazil, where it is associated with skin irritation and feather loss. An updated key to males and females of the genus Fainalges Gaud & Berla, 1963 is provided, and previous records of feather mites causing injuries in birds are briefly discussed.
A new coccidian species, Isospora melanotidis n. sp. from the blue mockingbird Melanotis caerulescens (Swainson), from Morelia, Michoacán State, Mexico. It is described and characterized molecularly. Sporulated oöcyst of the new species are subspherical, 25‒29 × 21‒25 (26.9 × 23.1) µm, (n = 30), with a length/width (L/W) ratio 1.0‒1.1 (1.04). Wall bi-layered 0.6‒1.1 (0.8) thick, clear outer and dark interior. One polar granule present, but micropyle and oöcyst residuum are absent, Sporocysts are ovoidal, measuring on average 14‒22 × 10‒13 (16.6 × 10‒13) µm, with a L/W ratio of 1.5; Stieda, sub-Stieda and para-Stieda bodies are present. A sporocyst residuum is present as a diffuse mass of granules. The 18S rRNA gene loci segment of Isospora sp., used for phylogenetic analysis by means of a maximum likelihood (ML) tree, revealed that Isospora sp., from M. caerulescens is distinct from Isospora sp., from Bewick’s Wren Thryomanes bewickii, with node support and bootstrap length of 91.5
The platyhelminth Microcotyle pomatomi Goto, 1899 was originally described from the gills of the bluefish, Pomatomus saltatrix (Linnaeus) collected in Newport, Rhode Island (USA). The original description was brief and lacked detailed morphological, anatomical, and molecular information. As a result, the species has long been the subject of several taxonomic studies, with historical records often attributed to different nominal taxa due to insufficient diagnostic features. In the present study, specimens of M. pomatomi were collected from the gills of Pomatomus saltatrix (Linnaeus) off the Algerian coast in the western Mediterranean, representing the first molecular characterization of this species in this region. Parasites were carefully examined, measured, and illustrated to provide a comprehensive morphological redescription. In parallel, molecular characterization was conducted using a partial fragment of the mitochondrial cox1 gene, and host identity was confirmed through analysis of gill tissue. The integration of morphological and molecular data allowed for a more precise identification and improved understanding of the species. The obtained cox1 sequence clearly supports the validity of M. pomatomi and distinguishes it from closely related congeners. Furthermore, our findings confirm the synonymy of several previously described species. Overall, this study clarifies the taxonomic status and phylogenetic position of M. pomatomi within the Microcotylidae.
The tapeworm genus Mariauxiella (Onchoproteocephalidea, Proteocephalidae) was recently revised and its species composition reappraised; however, its actual species diversity remains incompletely understood. In the present study, an integrative taxonomic approach combining morphological, ultrastructural, and molecular phylogenetic analyses was applied to proteocephalid tapeworms collected from the driftwood catfish Ageneiosus militaris (Siluriformes: Auchenipteridae) in the Upper Paraná River basin, Brazil. The evidence obtained supports the proposal of Mariauxiella saltogrande n. sp., the third species assigned to the genus. The new species can be differentiated from the most similar species, Mariauxiella brevifilis, by its body size, proglottis width, scolex shape, and the arrangement of the osmoregulatory canals in the proglottides. Phylogenetic analyses based on the partial large subunit nuclear ribosomal RNA (RNA28S) and the complete mitochondrial cytochrome c oxidase subunit I (MT-CO1) sequence data strongly supported the monophyly of Mariauxiella and recovered Mariauxiella saltogrande n. sp. as sister to M. brevifilis. The discovery of this new species expands the known diversity of Mariauxiella and provides further evidence for the usefulness of integrative taxonomy in resolving species boundaries and evolutionary relationships among Neotropical proteocephalids.
As part of a project to discover the diversity of fish parasites from Acapulco Bay on the coast of Guerrero in the Mexican Pacific, four species of the Monopisthocotyla (including two new species) and a species of the Polyopisthocotyla are described and compared with congeneric species: Octouncuhaptor sp. from the gills of the blue bobo, Polydactylus approximans (Lay & Bennett, 1839); Pseudempleurosoma sp. (Dactylogyridae) from the oesophagus of the yellow bobo Polydactylus opercularis (Gill); Acanthocercodes bullardiodes n. sp. and Acanthocercodes pacificus n. sp. (Diplectanidae) (all of the Monopisthocotyla) from the gills of P. opercularis (type host for both) and P. approximans; and Microcotyloides impudicus Caballero, Bravo & Grocott, 1955 (Polyopisthocotyla: Microcotylidae) from the gills of P. approximans. Octouncuhaptor sp. is mainly distinguished from its unique congeneric species, Octouncuhaptor eugerrei Mendoza-Franco, Roche & Torchin, 2008, on Eugerres brasilianus (Cuvier) (Gerreidae) from Panama by the morphology of the copulatory complex. Octouncuhaptor sp. represents a new species, but a specific name is not proposed for a single specimen in which the position of the structures of the internal soft organs (i.e., prostatic reservoir and seminal vesicle) are not visible, and those hard parts of the anatomy are not well defined to permit a complete description. The new diplectanids are distinguished from their congeners by the morphology and the size of the sclerotized parts of the haptor and peduncular spines. Measurements, supplementary observations, and new illustrations for Pseudempleurosoma sp. and M. impudicus are provided. The occurrence of interoceanic species of Acanthocercodes and Microcotyloides from the coasts of the Gulf of Mexico, South Atlantic Ocean (Brazil), and Mexican Pacific are briefly discussed.
Monopisthocotyls represent one of the most diverse groups of ectoparasites associated with Neotropical freshwater fishes; however, their diversity in the Peruvian Amazon remains poorly known. The present study aimed to describe new species of monopisthocotyls parasitizing the gills of Metynnis luna Cope collected in the Nanay River, Loreto, Peru. Twenty specimens of M. luna were examined, from which five new species of monopisthocotyls belonging to the family Dactylogyridae were recovered: four species of the genus Anacanthorus Mizelle Price, 1965 and one species of Notozothecium Boeger Kritsky, 1988. Specimens were fixed in 96
The type species of the aporocotylid blood flukes of the genus Psettarium Goto & Ozaki, 1930, P. japonicum (Goto & Ozaki, 1929) from Takifugu pardalis (Temminck & Schlegel) and Takifugu snyderi (Abe), is redescribed. In addition, three new and two unidentified species of the genus are described: Psettarium gotoi n. sp. from T. pardalis and Takifugu flavipterus Matsuura, Psettarium ozakii n. sp. from T. flavipterus, Psettarium shimazui n. sp. from Takifugu alboplumbeus (Richardson), Psettarium sp. 1 from T. pardalis and Psettarium sp. 2 from Takifugu porphyreus (Temminck & Schlegel). Each of the three new species can be variously differentiated from the congeners by the combination of the ovary position, testis distribution, the number of tegumental spine rows, the length of oesophagus, anterior caecum, metraterm and the confluent part of the vas deferens. The definition of the genus Psettarium has been emended. Psettarium pseudupenei (Lebedev & Parukhin, 1972) and Psettarium rachycentri (Lebedev & Paruchin, 1972) are treated as incertae sedis, as a conical projection at the male terminalia is lacking and the uterus turns clockwise in the former species, and, in the latter species, the male terminalia is posterior to oötype and the posterior caeca have thornlike projections. Psettarium now comprises 19 species including two Psettarium spp. from T. pardalis and T. porphyreus, nine of which infect Takifugu spp. Phylogenetic analyses of 28S rDNA and ITS2 rDNA sequences from five Psettarium species parasitizing Takifugu spp. revealed a monophyletic group. Each species formed a distinct clade based on 28S rDNA, with P. gotoi n. sp., P. sinense, and P. shimazui n. sp. closely related; this relationship was also supported by cox1 analysis.
Aglaiogyrodactylus Kritsky, Vianna Boeger, 2007 comprises ectoparasitic metazoans recorded mainly on the body surface of loricariid fishes. Although the genus currently includes only eight species, its actual diversity remains largely underestimated. In this study, three new species of Aglaiogyrodactylus collected from specimens of Hisonotus spp. in Brazil are described, and a new locality record of Aglaiogyrodactylus pedunculatus Kritsky, Vianna Boeger, 2007 is reported. The descriptions are based on diagnostic morphological characteristics, with the male copulatory organ as the main distinguishing structure. Aglaiogyrodactylus matildeae n. sp. presents an accessory piece composed of two branches: a sinistral spatulated branch and a dextral tubular branch. Aglaiogyrodactylus nonnae n. sp. possesses an accessory piece divided into three branches: two sinistral spatulated branches that serve as a guide for the male copulatory organ and a bifurcated dextral branch derived from an annular structure. Aglaiogyrodactylus marinae n. sp. presents an accessory piece formed by three branches, one spatulated sinistral branch with a semicircular end, and dextral branches with distal ends having inconspicuous digitiform projections. These descriptions expand the taxonomic knowledge of Aglaiogyrodactylus and document the occurrence of new lineages associated with Hisonotus spp. in southern Brazil.
Fourteen species of monopisthocotyls were reported from the gills of Triportheus albus Cope (Characiformes: Triportheidae) collected from the Itaya River, Peru. Nine species belonged to Anacanthorus Mizelle & Price, 1965: seven previously described species: Anacanthorus acuminatus Kritsky, Boeger & Van Every, 1992, Anacanthorus alatus Kritsky, Boeger & Van Every, 1992, Anacanthorus bellus Kritsky, Boeger & Van Every, 1992, Anacanthorus euryphallus Kritsky, Boeger & Van Every, 1992, Anacanthorus quinqueramus Kritsky, Boeger & Van Every, 1992, Anacanthorus formosus Kritsky, Boeger & Van Every, 1992, and Anacanthorus ramulosus Kritsky, Boeger & Van Every, 1992, and two new species described herein. Three species belonged to Ancistrohaptor Agarwal & Kritsky, 1998: Ancistrohaptor falciferum Agarwal & Kritsky, 1998, Ancistrohaptor falcunculum Agarwal & Kritsky, 1998, and Ancistrohaptor forficata Diniz, de Sousa, Yamada & Yamada, 2025; and two to Jainus Mizelle, Kritsky & Crane, 1968: Jainus iquitensis Morey, Viana, Chota & Chero, 2025 and Jainus sardinae Morey, Viana, Chota & Chero, 2025. Anacanthorus itayensis n. sp. is characterized by a long sclerotized sigmoid male copulatory organ (MCO) with submedial cirral "feather" and by a four-branched accessory piece in which the second branch terminates in a fish-like fin, the others bifurcate into sub-branches with pointed tips. Anacanthorus ypsiloniformis n. sp. is characterized by an elongate, slightly conical MCO curving ventrally and terminating in a rounded, slightly tapered distal tip bearing a dense crown-like cluster with submedial small spines, and by a distinctively Y-shaped accessory piece with two divergent arms arising proximally: one broader and blunt-ended with a comb-like denticulate distal margin, the other narrower and more rounded distally. This study constitutes the first comprehensive record of monopisthocotyls from T. albus in Peru and documents one of the most species-rich dactylogyrid assemblages reported from a single host species of Triportheus Cope in the Neotropical region.
The dactylogyrid fauna recorded in Trachelyopterus galeatus (Actinopterygii: Auchenipteridae) is composed of species belonging to three genera, namely Cosmetocleithrum Kritsky, Thatcher, and Boeger, 1986, Vancleaveus Kritsky, Thatcher, and Boeger, 1986, and Demidospermus Suriano, 1983. During a helminthological survey of T. galeatus from the Ubaldinho weir, Ceará state, Brazil, two new dactylogyrid species were found on the gills of this host. Philocorydoras lophus n. sp. can be distinguished from all congeners by the morphology of the copulatory complex, accessory piece with a crest-shaped flap in the medial portion, and a robust funnel-shaped male copulatory organ (MCO) with a round distal end, whereas all the other congeners possess thin funnel-shaped MCO with tapering distal end. Ameloblastella conus n. sp. differs from all congeners by having a ventral bar with a robust median projection; an MCO with 3½–4½ rings, and mainly by having a sclerotized vaginal duct with a cone-shaped distal portion. This is the first record of species of these two genera (Philocorydoras and Ameloblastella) in a host of the Auchenipteridae.
The male of Ixodes (Afrixodes) lunatus Neumann, 1907 (Acari: Ixodidae) is described for the first time and the female is redescribed based on specimens ex tenrecs (Afrosoricida: Tenrecidae) and a rat (Rodentia: Muridae) from Madagascar. Males and females of this species are different from other Malagasy species of the subgenus Afrixodes Morel, 1966, by the overall larger size, development of lateral carinae on scutum, shape of basis capituli, size and development of spurs on coxae and development of syncoxae.
To date, only a single species of the digenean genus Macvicaria Gibson Bray, 1982—Macvicaria obovata (Molin, 1859)—has been reported from southern African coastal waters, infecting three fish species (two sparids and one cheilodactylid). Given the general paucity of information on digeneans from marine fishes in this region, the present study aimed to explore the diversity of these parasites in the endemic sparids the Cape white seabream Diplodus capensis (Smith) and the zebra seabream Diplodus hottentotus (Smith). By integrating molecular data (based on 28S rDNA, ITS2 rDNA, cox1 mtDNA and nad1 mtDNA) with morphometric and morphological characterisation, three new species of Macvicaria were identified from these fish hosts in South Africa and Namibia. These are described herein as Macvicaria umbungu, Macvicaria tsitsikamma and Macvicaria peetvermaaki. This study represents the first record of species of Macvicaria from D. capensis and is the first report of a representative of this genus from Namibia. The newly generated molecular data will be valuable for future phylogenetic studies, accurate species identification, and linking different life stages of Macvicaria spp. in southern Africa. This study provides insight into the endemism of marine fish trematodes in southern Africa and explores biogeographical links between southern Africa and the Mediterranean fish trematode fauna.
The sacred kingfisher Todiramphus sanctus is a widespread bird species that is non-migratory in New Zealand, in contrast to elsewhere in the world. We describe a new species of Skrjabinoclava, a genus of acuariid nematodes, recovered from the oropharynx of sacred kingfishers in New Zealand. This is the first record of Skrjabinoclava in Australasia and the first publicly available DNA sequence for the genus. Skrjabinoclava pharyngophila n. sp. is unique in its infection site, occupying the oropharyngeal mucosa, which is atypical for Skrjabinoclava species, which usually infect the proventriculus or oesophagus. Morphological and molecular analyses confirm the distinctiveness of this new species, with DNA sequencing placing it within the family Acuariidae. The prevalence of infection was high in North Island birds, while none were found in South Island birds, suggesting the parasite is geographically restricted, possibly due to the distribution of intermediate hosts or the sedentary behavior of the host population. The presence of the parasite in New Zealand sacred kingfishers and its unique infection site offers new insights into the evolution of parasitism in isolated populations.
Cory’s Shearwater (Calonectris borealis), a migratory seabird from the Procellariidae family, is widely distributed across the Atlantic Ocean. It breeds on islands of Azores, Madeira, Canary, and Berlengas, and winters in coastal areas of South America and Africa. This species’ wide habitat range contributes to pathogen exchange across global regions. Plasmodium, a genus of apicomplexan parasites causing avian malaria, affects many wild bird species worldwide. Although rare in seabirds, Plasmodium infections can significantly impact these hosts. We identified and characterized a new Plasmodium species in an adult male C. borealis found live-stranded on the northern coast of São Paulo, Brazil, during the daily activities of the Santos Basin Beach Monitoring Project (PMP-BS). The bird was rescued and kept in rehabilitation for 61 days but was euthanized due to poor prognosis. Blood smears revealed parasitemia varying from 0.04
The new genus Pseudoangiostoma gen. n. (Nematoda: Angiostomatidae) was established on the basis of the type species Pseudoangiostoma onychodactyla comb. n. (syn. Angiostoma onychodactyla), which parasitizes the stomach and intestine of some species of the genus Onychodactylus (Amphibia: Hynobiidae) in Japan. Pseudoangiostoma gen. n. differs from the genus Angiostoma by having a lower inverted truncated cone-shaped buccal cavity, a thicker and strongly curved buccal wall, and for parasitizing hosts of the order Caudata. The phylogenetic pattern provided substantial suppot for the new genus, exhibiting two major divergent lineages (diverged in terrestrial gastropods vs. salamanders). This study indicated that P. onychodactyla comb. n. did not originate from host-switching event from terrestrial gastropods to salamanders. However, other species of Angiostoma parasitic in amphibians and reptiles are still considered insertae sedis.
The myxozoan genus Triangula Chen Hsieh, 1984 has a strong morphological similarity with the genus Cardimyxobolus Ma, Dong, Wang, 1982, and their distinction presents a complex taxonomic problem that cannot be resolved without molecular data. Here we first provided phylogenic reconstructions of Triangula spp. and Cardimyxobolus spp. using molecular data from Triangula perccotti (Dogiel Achmerov in Achmerov, 1960). Polysporic plasmodia of T. perccotti were collected from the skin of P. glenii caught in the Lake Bolon basin (Amur system) and molecularly characterized based on the 18S rRNA gene. In the phylogenetic tree, T. perccotti appeared as a sister species to Cardimyxobolus donkoi (Ishizaki, 1955). The T. perccotti + C. donkoi clade was nested within one clade with other of species of Triangula Chen Hsieh, 1984 and Cardimyxobolus Ma, Dong, Wang, 1982. It was shown that neither Triangula spp. nor Cardimyxobolus spp. appeared as monophyletic groups.
Scanning electron microscopy (SEM) studies of specimens (including some paratypes) of four North and Central American species of Rhabdochona Railliet, 1916 (Rhabdochonidae), all intestinal parasites of fishes, made it possible to redescribe in detail several taxonomically important morphological features of these nematodes that are difficult to observe using light microscopy (LM). Three of these species, R. cascadilla Wigdor, 1918, mainly from cyprinids in North America; R. cubensis Moravec Coy Otero, 1987, from a poeciliid in Cuba; and R. longleyi Moravec Huffman, 1988, from blind catfishes in subterranean waters in the USA, were studied by SEM for the first time. Surprisingly, the number of anterior prostomal teeth, one of the most important taxonomic features in Rhabdochona, was found to be 10 in R. cubensis, rather than 6 as originally reported; this indicates that the species belongs to the nominotypical subgenus Rhabdochona. Several morphological details in these species are confirmed or reported for the first time, such as the presence of sublabia in all species and the presence of ventral precloacal cuticular ridges in R. cascadilla. The shape of the deirids in R. kidderi specimens from the atypical host Typhliasina pearsei (Ophidiiformes) confirms their specific identification.
Aethycteron malleusodes n. sp. (Monopisthocotyla: Dactylogyridae) is described from the gills of the federally threatened leopard darter, Percina pantherina (Moore & Reeves) (Perciformes: Percidae), from the Cossatot River (Little River Drainage of the Red River System) in the Ouachita Mountains of Arkansas, USA. Aethycteron malleusodes n. sp. is morphologically most similar to Aethycteron malleus (Mueller (1938) by possessing a ventral bar with a posterior medial protuberance, a relatively straight male copulatory organ (MCO) with a distal spiraling sheath, and tip of the MCO with a pronounced flange. The body size and sclerites are generally smaller in A. malleusodes n. sp. and the spiraling sheath wraps around the MCO 2.5-3 times, compared to 3-4 times in A. malleus. We document the first helminth described from this threatened fish species. This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:232173AF-D776-48BD-9A8E 660C1764C006.
A new species Hormius orthagae Gupta Belokobylskij n. sp. (Hymenoptera: Braconidae: Hormiinae) is found parasitizing young larvae of mango leaf webber Orthaga exvinacea (Hampson) (Lepidoptera: Pyralidae) feeding within the leaf webs of Mangifera indica L. in Central India. In the present paper, the new ectoparasitoid species is described and biological notes on its host are provided with illustrations.
Monogeneans are fish ectoparasites which infested commonly gill filament. They are characterised by their sclerotized haptoral and genital structures. Morphological study of gill monogeneans was conducted at Lebamzip, Center Region of Cameroon. Fish were caught along Cesala River. Each monogenean was mounted between slide and coverslip in a drop of GAP mixture. Drawings of the sclerotized structures were made using Corel Draw and measurements were taken on Amscope. Four monogeneans species belonging to the genus Dactylogyrus were identified. One new species is described Dactylogyrus cesalaensis n. sp. from Enteromius aspilus and three described species as follows: Dactylogyrus aspili from Enteromius aspilus; Dactylogyrus mendehei and Dactylogyrus nyongensis from Enteromius guirali are rediscribed. Each monogenean species presented a filamentous anchor and MCO with a flame type accessory piece. Particularly, Dactylogyrus cesalaensis n. sp. has a W-shaped dorsal bar; filamentous hooks; vagina shaped like a dagger blade. For Dactylogyrus aspili: dorsal bar is V-shaped; pair I of hooks most developed without filament; pairs II-VII are filamentous; vagina is a leaf-like piece with spiny ends. Concerning D. mendehei: pair I of hooks without filament; pairs II-VII are filamentous; dorsal bar U-shaped. For D. nyongensis: dorsal bar arched; filamentous hooks; three forms of MCO belonging to the flame type observed; vagina comma-shaped. All encountered monogeneans are classed in the Dactylogyrus wunderi type. Colonisation-extinction phenomena and variability of abiotic factors inherent to the study area explained the parasitic richness and morphometric differences observed during this study, respectively.
