Caudal Bursa Research Articles

Redescription of Physaloptera sarcophili Johnston & Mawson, 1940 and the description of Physaloptera dasyuri sp. nov. (Nematoda: Spirurida) parasitic in Australasian dasyurid marsupials

ABSTRACT Physaloptera sarcophili Johnston & Mawson, 1940 (Nematoda: Spirurida), originally described from the Tasmania devil, Sarcophilus harrisii (Boitard), is redescribed based on additional material from this host species. Physaloptera dasyuri sp. nov. is described from quolls, Dasyurus maculatus (Kerr) from Tasmania, Dasyurus hallucatus Gould from the Northern Territory and the Kimberly District of Western Australia and Dasyurus albopunctatus Schlegel from New Guinea. The two nematode species are distinguished by measurements, with values of those of P. sarcophili being approximately twice as large as those of P. dasyuri sp. nov. and by differences in the ratio of right to left spicule lengths. Limited morphological variation in the distribution of the papillae on the caudal bursa is described. Both species are differentiated from congeners in Australian mammals by the presence of four sessile post-cloacal papillae arranged in a single row, the arrangement of the three pairs of post-cloacal sessile papillae and spicule measurements. The differentiation of both species from congeners in South American marsupials and eutherian carnivores is also discussed.

A New Species of Heligmonellidae (Nematoda) in Euryoryzomys russatus (Rodentia: Sigmodontinae) in the Atlantic Forest of Northeast Brazil.

The genus Stilestrongylus (Freitas, Lent, and Almeida, 1937) is defined by having 24 or more subequal cuticular ridges, an asymmetrical caudal bursa, and a hypertrophied genital cone. It comprises 25 recognized species, mainly parasitizing cricetids, and shows significant diversification linked to the evolution of its hosts. Stilestrongylus magnumspiculum n. sp. is a newly described nematode species identified in the small intestine of the rodent Euryoryzomys russatus (Cricetidae, Sigmodontinae) from the Atlantic Forest of Northeast Brazil. This study aims to characterize the new species and its prevalence in host populations. A total of 43 Euryoryzomys russatus individuals were collected and analyzed for parasitic infections. Morphological features of Stilestrongylus magnumspiculum n. sp. were examined, focusing on the number of ridges, synlophe characteristics, caudal bursa type, lobe hypertrophy, and the spicule length to body length ratio. The new species exhibited a prevalence of 21% among the sampled hosts. Distinctive morphological features were observed, including:the synlophe structure exhibited specific ridge patterns that differentiate it from other species within the genus; the caudal bursa was identified as a type 2-2-1; hypertrophy of the right lobe was observed, indicating notable morphological adaptation; rays 4 and 5 were found to be equivalent in size and diverged at the distal end; the spicule length to body length ratio (SpL/BL) was measured at 30-36%, representing the largest ratio recorded for the genus. In comparison, other Stilestrongylus species displayed the following ratios: S. rolandoi (21-33%), S. lanfrediae (25-29%), S. kaaguyporai (20-24%), S. inexpectatus (20-23%), and S. stilesi (26-28%). This report presents Stilestrongylus magnumspiculum n. sp. as a new species of nematode, contributing to the diversity of the genus Stilestrongylus. The findings underscore the importance of studying host-parasite interactions within the Atlantic Forest ecosystem and provide a basis for future ecological and parasitological research.

New species of the genus Alippistrongylus (Nematoda: Trichostrongylina) parasitic in Delomys dorsalis (Rodentia: Sigmodontinae) in the Atlantic Forest of Rio de Janeiro, Brazil.

We describe a new species of the genus Alippistrongylus (Nematoda: Trichostrongylina) in the small intestine of Delomys dorsalis (Rodentia: Sigmodontinae) found in Itatiaia National Park (Parque Nacional do Itatiaia, PNI), state of Rio de Janeiro, Brazil. The new species can be distinguished between the other two species previously described by the following morphological characteristics: pattern of the rays from the caudal bursa rays in males and the spherical-shaped appendage in the female. Additionally, we provide molecular genetic data from the new species. The discovery of Alippistrongylus itatiaiaensis sp. n. expands our understanding of nematode diversity and underscores the importance of parasite studies in biodiversity conservation. Its occurrence in a preserved area like the PNI emphasises the role of such habitats in maintaining unique ecological interactions.

Description of Pudica wandiquei n. sp. (Heligmonellidae: Pudicinae), a nematode found infecting Proechimys simonsi (Rodentia: Echimyidae) in the Brazilian Amazon.

A new species of nematode parasite of the subfamily Pudicinae (Heligmosomoidea: Heligmonellidae) is described from the small intestine of Proechimys simonsi (Rodentia: Echimyidae) from the locality of Nova Cintra in the municpality of Rodrigues Alves, Acre state, Brazil. The genus Pudica includes 15 species parasites of Neotropical rodents of the families Caviidae, Ctenomyidae, Dasyproctidae, Echimyidae, Erethizontidae, and Myocastoridae. Four species of this nematode were found parasitizing three different species rodents of the genus Proechimys in the Amazon biome. Pudica wandiquei n. sp. can be differentiated from all other Pudica species by the distance between the ends of rays 6 and 8 and the 1-3-1 pattern of the caudal bursa in both lobes.

Oswaldocruzia franciscoensis n. sp. (Nematoda: Molineidae) in Leptodactylus macrosternum Miranda-Ribeiro, 1926 (Anura: Leptodactylidae) from Caatinga morphoclimatic domain, Brazil: morphological and molecular characterisation.

A new species of Oswaldocruzia Travassos, 1917 (Nematoda, Molineidae), parasite of Leptodactylus macrosternum Miranda-Ribeiro, 1926 (Anura: Leptodactylidae), from Caatinga morphoclimatic domain, Brazil, is described based on morphological and molecular data. Oswaldocruzia franciscoensis n. sp. is characterised by an anterior extremity with a cephalic vesicle divided into two portions, a body covered by cuticular longitudinal ridges, and cervical alae. Males of the new species have caudal bursa of type I with a 2-1-2 pattern, spicules divided into a shoe, bifurcated fork, and blade with two unequal branches, in which the longer branch bifurcates at its distal portion end and the smaller branch with three distal processes, each with distal bifurcations. Females have didelphic and amphidelphic uteri, an ovijector divided into vestibule, anterior and posterior sphincters, and anterior and posterior infundibula. The new species differs from its Neotropical congeners that have caudal bursa of type I, based on the presence of cervical alae and by having a spicular blade distally divided into two unequal branches, with the longer branch bifurcating at its distal portion and smaller branch with three distal processes, each distally bifurcated. The partial 18S rDNA sequence generated for Oswaldocruzia franciscoensis n. sp. is the first of a representative belonging to this genus in the Neotropical region.

New Pudicinae (Nematoda, Heligmonellidae) parasite of Trichomys fosteri (Rodentia: Echimyidae) from Pantanal, Brazil.

Pudica trichomysae n. sp. (Trichostrongylina, Heligmosomoidea, Helligmonellidae, Pudicinae) from the small intestine of Trichomys fosteri (Rodentia: Echimydae) from the Pantanal of Mato Grosso do Sul is described by light and scanning electron microscopy. Pudica trichomysae n. sp. is characterized by caudal bursa type 2-2-1, proportion of spicules length in relation to body length (SpL/BL) of 17 to 18% left and right, respectively. Dorsal ray divided at about the distal third into two branches, each branch divided into two long sub-branches, rays 9 and 10. Furthermore, this study shows for the first time details of the anterior region demonstrating papillae organization, amphids, derides, and opening of the excretory pore. The posterior end of the caudal bursa showed detail of the genital cone, papillae, and ray 1, and in the female, it showed interrupted ridges between the vulva and anus. In conclusion, the present species is the seventeenth described in the genus in South America and the first in Pantanal.

Redescription of the two most recorded Physaloptera (Nematoda: Physalopteridae) parasitizing lizards in the Americas: first step towards a robust species identification framework.

Despite being the two most recorded species of Physaloptera from lizards in the Americas, P. retusa and P. lutzi are either incompletely described or have accumulated inaccurate morphological data through the years. Here, we redescribe both species from Tropidurus torquatus in the State of Minas Gerais, Brazil, including evaluation ofspecimens from the Coleção Helmintológica do Instituto Oswaldo Cruz. In P. retusa, the presence and location of amphids, presence and pattern of porous areas on pseudolabia, detailed pattern of cuticular ornamentations on ventral surface of the caudal bursa, structure of cloacal labia, presence of dome-shaped elevation between the last pair of postcloacal papillae and location of phasmids in males, were revealed for the first time. Additional morphometric data are also provided. In P. lutzi, the detailed morphological analysis revealed for the first time, porous areas on pseudolabia, as well as presence of amphids, phasmids, and the detailed ornamentation and papillae arrangement on the male bursa. Also, the presence of an internal tripartite and an external triangular labial tooth in the specimens were observed to be constant, diverging from the assertions by other authors. Finally, in P. lutzi was possible to observe that deirids are consistently located close to muscular oesophagus base with excretory pore slightly posterior to it, and the vulva is always close to anal aperture. The present observations confirmed the validity of P. lutzi and strengthened its taxonomic diagnosis. An up-to-date list of records of both species is provided, including a brief discussion on their host spectrum and geographic range.

A NEW SPECIES OF ALLINTOSHIUS (NEMATODA: HELIGMOSOMOIDEA) FROM TWO SPECIES OF BATS IN BRAZIL.

Allintoshius Chitwood, 1937 is the only genus of the family Ornithostrongylidae (Travassos, 1937) Durette-Desset and Chabaud, 1981 that parasitizes bats. Currently, there are 10 valid species in the genus, of which 3 were described from Brazil. This study describes a new species of Allintoshius and records the first occurrence of a nematode of this genus parasitizing Artibeus lituratus (Olfers). Allintoshius gomesae n. sp. is characterized by having anterior region coiled, cephalic vesicle with cuticular dilation striated transversely, and claviform esophagus. Synlophe in females consists of 16 cuticular ridges at the mid-body. Males have large caudal bursa, and conic and small spicules, and the gubernaculum is absent. Females have uterus didelphic, amphidelphic, tail tip tapered, and ovijector divided into 2 divergent branches, subequal in length. The new species differs from its congeners especially by the shape of the tail tip, vulvar opening, and size of spicules. Allintoshius gomesae is the fourth species of Allintoshius from Brazil and the first report in Ar. lituratus, increasing the number of species recognized of the genus.

Morphological variability of Oswaldocruzia filiformis (Nematoda: Molineidae) in amphibians from European Russia

The morphological and morphometric variability of the nematode Oswaldocruzia filiformis from ten amphibian species (Pelophylax ridibundus, Pelophylax lessonae, Pelophylax esculentus, Rana arvalis, Rana temporaria, Bufo bufo, Bufotes viridis, Pelobates vespertinus, Bombina bombina and Lissotriton vulgaris) was studied. The sampling was performed during the period of 2018–2020 in fifteen localities of European Russia. We examined the following morphological features: the number of crests in mid-body level, the shape of lateral alae, the shape of cephalic vesicle, shape and structure of spicules in males, the shape and structure of male caudal bursa, the shape and structure of the dorsal ray of bursa; and the measurements of nine morphometric characteristics in nematode females and seven characters in males, subjected to variability. Significant differences in the variability of morphometric characteristics of O. filiformis of both sexes in different amphibian species and amphibians from various regions were revealed. Likewise, significant differences were revealed for most of morphometric features of O. filiformis from amphibians of the same species from different regions of Russia. The type of male caudal bursa and the structure and shape of spicules were identical in all O. filiformis males studied. Likewise, we have not found variability in the structure of the reproductive system in O. filiformis females. Variability was noted in the shape and size of the cephalic vesicle and lateral alae, in the number at the mid-body level, in the shape and structure of the dorsal rib of male caudal bursa. Differences in morphometric characteristics of O. filiformis from amphibians of the same species from different regions of Russia can be explained by the phenotypic plasticity of the species. While variations in the nematode morphology from different amphibian species are caused by the host-induced morphological variability of the parasite. Differences in the size of nematodes and their morphology in different regions of Russia studied may be caused by changes in ecological conditions in amphibian habitats. The broad morphological variability of the nematode O. filiformis increases the adaptive capabilities of the helminth and allows it to parasitize a wide range of hosts.

Pseudocapillaria (Ichthyocapillaria) bumpi n. sp. (Nematoda: Capillariidae) Parasitising West African Lungfish Protopterus annectens (Owen, 1839) (Lepidosireniformes: Protopteridae) in Mozambique and Its Phylogenetic Position Within Capillariid Nematodes.

Pseudocapillaria (Ichthyocapillaria) bumpi n. sp. (Nematoda: Capillariidae) is described from specimens infecting the digestive tract of the West African lungfish, Protopterus annectens (Owen) (Lepidosireniformes: Protopteridae). Nematodes were collected in Karingani Game Reserve, Southern Mozambique and studied using light microscopy; obtained sequences of the 18S ribosomal (18S rRNA) gene used for phylogenetic studies. The new species is assigned to Pseudocapillaria Freitas, 1959 by having a stichosome consisting of a single row of stichocytes and ventrolateral lobes on the male tail as well as by lacking spines on the specular sheath, caudal alae, a membranous caudal bursa, and a lateral expansion of the caudal end. It is also assigned to the sub-genus Ichthyocapillaria Moravec, 1982 by having a membrane between the ventrolateral lobes and by lacking a vulvar appendage. Pseudocapillaria (I.) bumpi n. sp. differs from its nominal congeners by having a comparatively large body size with relatively long spicule, bearing the thin membrane non-extending further than ventrolateral lobes in males and relatively smaller eggs without protruding polar plugs. It is the 20th species of the genus, the first from the Afrotropical Realm, and the first from any lungfish species. Phylogenetic analyses suggested that P. (I.) bumpi is deeply nested in a clade that associates species of the genera Pearsonema, Aonchotheca and Baruscapillaria.

Morphological identification of Nematodirus spathiger nematodes (Nematoda, Molineidae) obtained from the small intestine of sheep

Strongyloidiases are caused by nematodes of the suborder Strongylida and are the most widely prevalent group of gastrointestinal helminthiases of sheep in many regions of the world. Among gastrointestinal strongylids, the helminths of the genus Nematodirus are represented by the largest number of species and highest infection rates in sheep. Nematodirosis causes significant economic losses in the sheep industry through decreased sheep productivity, delayed growth and development of young animals, and a reduced resistance to other diseases. Timely and accurate diagnosis of nematodirosis and identification of the pathogen will effectively prevent the disease and help to carry out treatment and prevention measures. Therefore, the aim of the work was to study the definitive morphometric characters of mature males and females of Nematodirus spathiger Railliet, 1896, obtained from the small intestine of domestic sheep. The results of experimental studies showed that nematodes of this species morphologically are characterized by a thin filiform body, a vesicle at the head end and a chitinous tooth in a short oral capsule. The differential morphological features of male nematodes of N. spathiger include specifics of the structure of spicules, their distal end and the shape and location of the rays of the caudal bursa; in females, those are the features of the structure of the vulva and tail end. In identification of male nematodes of N. spathiger, it is proposed to use 40 metric parameters, of which 11 characterize the overall size of the body, esophagus and vesicles, 24 refer to the size of the tail bursa, 5 to the size of the spicules and the enveloping membrane. To help identify the females of N. spathiger, 25 parameters are chosen, of which 14 also characterize the overall size of the body, esophagus and head vesicle, 6 refer to the size of the cuticular formations of the vulva and its location, and 5 to the size of the tail end, the location of the anus and the size of the tail spike.

New species of Hassalstrongylus (Trichostrongyloidea: Heligmonellidae) in the large-headed rice rat Hylaeamys seuanezi, in the Atlantic Forest of northeast Brazil.

A new species of Trichostrongyloidea (Nematoda: Heligmonellidae), Hassalstrongylus lauroi n. sp., is described from specimens collected from the small intestine of the rodent Hylaeamys seuanezi in the Atlantic Forest of northeastern Brazil (Igrapiúna, state of Bahia). The genus Hassalstrongylus includes 17 species, which parasitize rodents occurring in the Neotropical and Nearctic regions. It differs from the genus Stilestrongylus through its smaller number of ridges in the synlophe and through the size of the genital cone. The main taxonomic characteristics of this new species are the subsymmetrical caudal bursa of type 2-2-1, ray 8 branching out at the base of the dorsal trunk, right lobe smaller than the left, and rays 4 and 5 of robust nature. In addition, the ornamental ray 5 and the robustness of ray 4 on the male caudal bursa, along with the modification of the ridges of the posterior end of the female, allow us to consider the specimens found to be a new species.

Paracapillaria (Paracapillaria) gastrica n. sp. (Nematoda: Capillariidae) from the marine fish Synodus variegatus Lacépède (Synodontidae, Aulopiformes) off New Caledonia.

Based on light and scanning electron microscopical studies, a new nematode parasite, Paracapillaria (Paracapillaria) gastrica n. sp. (Capillariidae), is described from the stomach of the marine fish (variegated lizardfish) Synodus variegatus (Lacépède) (Aulopiformes: Synodontidae) from off New Caledonia. This species is mainly characterised by the length of the spicule (267 µm), the proximal spicule end expanded to form a conspicuous folded, lobular rim, the presence of a well-developed caudal bursa supported by two lateral projections (rays) not adhering to the posterior border of body and by the size of eggs (54-60 × 24-27 µm) with non-protruding polar plugs. Paracapillaria gastrica n. sp. is the first known capillariid species parasitic in a host belonging to the fish order Aulopiformes and the first species of this genus reported from fishes in New Caledonian waters and the South Pacific Ocean.

A New Species of Bidigiticauda (Nematoda: Strongylida) from the Bat Artibeus planirostris (Chiroptera: Phyllostomidae) in the Atlantic Forest and a Molecular Phylogeny of the Molineid Bat Parasites

The nematode genus Bidigiticauda has 2 species (Bidigiticauda vivipara and Bidigiticauda embryophilum), which are parasites of bats from the Neotropical region. The present paper describes a new species of Bidigiticauda from a male Artibeus planirostris specimen collected in the Pratigi Environmental Protection Area in Bahia state, Brazil. The new species, Bidigiticauda serrafreirei n. sp., differs from B. embryophilum by having longer spicules, rays 5 and 6 arising from a common trunk and bifurcating in its first third, rays 3 and 4 emerging slightly separated from each other, and dorsal rays reaching the margin of the caudal bursa. The new species also differs from B. vivipara by the dorsal ray bifurcating at the extremity of the trunk. A molecular phylogenetic analysis was conducted to determine the evolutionary affinities of Bidigiticauda serrafreirei n. sp. within the Strongylida, which identified a clade that grouped Bidigiticauda with the other members of the Anoplostrongylinae. However, the molineid subfamilies did not group together, indicating that the family Molineidae is polyphyletic. Further analyses, which include additional taxa and genetic markers, should elucidate the complex relationships within the Molineidae, in particular its subfamilies and the evolution of the traits that define these groups.

On two genera of spiny Pudicinae (Nematoda: Trichostrongylina) parasites of the spiny rat Proechimys simonsi (Mammalia: Echimyidae) from Peru.

A new species of trichostrongyloid nematode, Acanthostrongylus secundus is described. It differs from the other species of the genus in the structure of the caudal bursa. Squamasnema amazonica is redescribed correcting the synlophe structure and moving the genus from Heligmonellinae to Pudicinae. Both species were collected in Proechimys simonsi from Peru. [Zoobank URL: urn:lsid:zoobank.org:act:EEDBD925-8539-4F5D-A276-4F735464BA6F].

Achatina fulica (Mollusca: Achatinidae) Naturally Infected with Caenorhabditis briggsae (Dougherty and Nigon, 1949) (Nematoda: Rhabditidae).

Specimens of the African snail Achatina fulica, collected in Bucaramanga, Colombia, were examined for parasites. Numerous specimens of Caenorhabditis briggsae were collected from the digestive tract of the snails and identified by the structure of male spiculum, caudal bursa, gubernaculum and precloacal lip in males, triangular tooth in metarhabdion, and protandrous hermaphrodites with a female:male ratio of 15:1 and with morphometry. DNA sequences of the ITS2 region of the ribosomal gene array from worms in this study matched with 99% similarity to published sequences of C. briggsae. A redescription of the species is provided. This is the first record of the species in South America.

A new heligmonellid (Nematoda) species of the genus Stilestrongylus in Euryoryzomys russatus (Rodentia: Sigmodontinae) in the Atlantic Forest, southern Brazil.

A new species of Nippostrongylinae (Nematoda: Heligmonellidae), Stilestrongylus rolandoi n. sp., is described from specimens collected from the small intestine of the rodent Euryoryzomys russatus in the Atlantic Forest (Santo Amaro da Imperatriz, Santa Catarina state, southern Brazil). The genus Stilestrongylus includes 23 species, which parasitize rodents occurring in the Neotropical region. Stilestrongylus aureus (Durette-Desset & Sutton, 1985) from Argentina, S. azarai (Durette-Desset & Sutton, 1985) from Argentina, S. flavescens (Sutton & Durette-Desset, 1991) from Uruguay, S. franciscanus (Digiani & Durette-Desset, 2002) from Argentina, S. gracielae (Digiani & Durette-Desset, 2006) from Argentina, and S. oryzomysi (Sutton & Durette-Desset, 1991) from Argentina are closely related to Stilestrongylus rolandoi n. sp., all having caudal bursa patterns of types 1-4 in one of the lobes. Stilestrongylus rolandoi n. sp. is distinguished from the aforementioned species by its ray 6 being short in relation to rays 4 and 5, which are long and robust, and by having caudal bursa patterns of types 1-4 in both lobes. The new species has 27 ridges in the mid-body in males, and 24 in females, and has one of the highest ratios of spicule length to body length (21-33%) in this genus.

First ocular report of Gurltia paralysans (Wolffhügel, 1933) in cat

A two-year-old cat from Tenerife, Canary Islands (Spain), presented with two months history of uveitis in the left eye. It had been treated for two months but still showed an active uveitis. After new treatment, eye examination showed a mobile worm in the anterior chamber. Following surgical removal, the worm was obtained. Morphological study revealed that it was a male metastrongyloid nematode (Nematoda: Metastrongyloidea) with caudal bursa and two similar spicules. Molecular tools based on the 18Sr RNA gene sequence identified the parasite as Gurltia paralysans, which is a neurotropic nematode previously found in South America. Therefore, this article describes the first report of ophthalmic case of parasitism by G. paralysans, and cites for first time this species out of South America.

A new species of Stilestrongylus (Nematoda, Heligmonellidae) from the Atlantic Forest of Misiones, Argentina, parasitic in Euryoryzomys russatus (Cricetidae, Sigmodontinae).

A new species of Heligmonellidae (Trichostrongylina, Heligmosomoidea), Stilestrongylus kaaguyporai n. sp. is described from the small intestine of Euryoryzomys russatus (Rodentia, Cricetidae, Sigmodontinae) from the Argentine Atlantic Forest, in the Misiones province. The new species was found at Campo Anexo Manuel Belgrano, Reserva de Vida Silvestre Urugua-í and Parque Provincial Urugua-í, with a prevalence of 73% in 15 hosts examined. Stilestrongylus includes 24 Neotropical species, all parasitic in rodents, mostly Sigmodontinae. Stilestrongylus kaaguyporai n. sp. can be differentiated from its congeners by the following characters: caudal bursa dissymmetrical with right lobe larger and pattern of type1-4 in both lobes, rays 6 not forming a lateral trident with rays 4 and 5, rays 8 with dissymmetrical pathway, genital cone hypertrophied with a conspicuous hood-like projection and females with a marked dorso-ventral torsion of the posterior end. This report is the second record of a Stilestrongylus species in E. russatus, increasing to nine the number of parasitic species known from this host.

Two new species of Oswaldocruzia (Nematoda, Molineidae) parasitising lizards in Ukraine

Two new species, Oswaldocruzia lisnykiensis sp. n. and Oswaldocruzia lacertica sp. n., are described from Anguis fragilis L. (Reptilia: Anquidae) and Lacerta agilis L. (Reptilia: Lacertidae) respectively. Both species belong to the Palaearctic group of species which have spicules divided in three main branches (blade, fork and shoe) with fork division above its distal third. The new species differs from all previously known Palaearctic species by several morphological characters: type of caudal bursa (type III in O. lisnykiensis and type I in O. lacertica), shape of spicules (blade distally divided into four tips and specific shape of shoe) and synlophe structure (narrow cervical alae consist of three crests in both species). Illustrated descriptions of O.lisnykiensis and O. lacertica based on 63 and 38 specimens respectively are presented. Host specificity and geographical distribution of the species are discussed. O.dispar is considered as a species inquirenda.