Arrangement Of Genital Papillae Research Articles

Two new species of Neofoleyellides (Nematoda: Onchocercidae) parasitising anuran amphibians in South Africa.

The genus Neofoleyellides was recently erected for a single species, Neofoleyellides boerewors from bufonid hosts in South Africa. In present study, we discovered two undescribed species of Neofoleyellides, namely N. steyni n. sp. and N. martini n. sp. parasitising frogs Amietia delalandii and Leptopelis natalensis, respectively. Both species differ from N. boerewors and between each other in shape and relative length of oesophagus, size of spicules, arrangement of genital papillae and morphology of caudal alae in males. Phylogenetic analysis based on concatenated fragments of the 18S ribosomal ribonucleic acid (18S rRNA) and the Cytochrome oxidase c subunit I (COI) genes confirmed both species as Neofoleyellides sister to Icosiellinae and Oswaldofilariinae.

Rhabditidoides aegus n. sp., an associate of stag beetles and sap flow in Japan

Rhabditidoides aegus n. sp. from a stag beetle, Aegus subnitidus subnitidus, from Nagoya, Japan, and obtained from the sap flow of an oak tree, Quercus serrata, from Ibaraki, Japan, is described and illustrated. In addition to its distinguishing generic characteristics, e.g., the arrangement of male genital papillae, ⟨v1, v2, v3d, CO, v4, (ph, ad, v5, v6), pd, v7⟩, the new species is characterised by a relatively stout body for both male and female, small stomatal flaps, a secretory pore-like opening, a pair of deirids, three pairs of postdeirids, and a pair of small subventral vulval papillae located just anterior to the female vulva. The new species is morphologically similar to R. humicolus, the species sharing two typological characters: a stomatal flap and vulval papillae. However, the new species is distinguished from R. humicolus by its relatively small vulval papillae, narrower gubernaculum, and the arrangement of genital papillae in which pd and v7 are clearly separate. In addition to the typological characters, the new species is distinguishable from all other species in the genus by its distribution range as it is the first Rhabditidoides species from East Asia.

Recharacterisation of three Parasitodiplogaster species based on morphological and molecular profiles

Three previously describedParasitodiplogasterspp.,P. nymphanema,P. obtusinemaandP. trigonemawere re-isolated from their type locality, Barro Colorado Island Research Station, Smithsonian Tropical Research Institute, in Panama. The re-isolated materials were morphologically observed to compare with the original descriptions and molecularly characterised by DNA sequences of the near-full-length small subunit and D2-D3 expansion segments of the large subunit of the ribosomal RNA genes. Although the male tail characters,i.e., arrangement of genital papillae and spicule and gubernaculum morphologies, were close to the original descriptions, a compressed stoma with two (right subventral and dorsal) teeth was observed for the first time and confirmed in the newly re-isolated materials. The molecular phylogenetic analysis revealed that the three re-isolated species are close toP. laevigata,P. citrinemaandP. popenema, forming theP. laevigatagroup in the genus, and this group was separated into three subgroups,P. citrinema +P. popenema(subgroup 1),P. nymphanema +P. obtusinema(subgroup 2) andP. laevigata +P. trigonemaand three undescribed species (subgroup 3). TheP. laevigatagroup is characterised by a relatively compressed stoma with two (right subventral and dorsal) teeth, arrangement of genital papillae (three or four precloacal and four postcloacal pairs), but distinguishable from each other by stomatal morphology,i.e., the shortest and most compressed being in subgroup 3, widest in subgroup 1, and intermediate in subgroup 2. Furthermore, a large and long spicule and gubernaculum were observed in subgroup 2 as its hypothesised apomorphy.

Recharacterisation and photo-documentation of five North American Bursaphelenchus species from C.L. Massey’s type material

The type specimens of fiveBursaphelenchusspecies described by Massey,i.e.,B. bestiolus,B. corneolus,B. elytrus,B. newmexicanusandB. wilfordi, were re-examined and photo-documented to update their descriptions in light of a contemporary understanding of the genus. The presence of a lateral field, basal swelling of stylet, P1 ventral single papilla of males and a pair of three-celled structures in females, which were not described or mentioned in the original descriptions, were observed, although the number of lateral incisures were not clarified because of sample condition. Within these five species, the intrageneric groupings ofB. bestiolusandB. wilfordihad been unclear. In the present study, because of newly observed morphological characters,B. bestiolusis considered to belong to thehofmanni-group, and is close toB. talonusandB. rufipennis. These three species form a species complex and are distinguished from each other only by female tail morphology. The species status ofB. wilfordiis still unclear, although, based on spicule morphology and structure and arrangement of genital papillae, we consider it to belong to thehofmanni-group, close toB. parvispicularis,B. paraparvispicularisandB. osumiana. However, female characters ofB. wilfordiare also similar to members of thecocophilus-group andParasitaphelenchus. Re-isolation and molecular identification are necessary to confirm the status of these species. By contrast, the affiliations ofB. corneoluswith thehofmanni-group andB. elytrusandB. newmexicanuswith theeggersi-group were confirmed. Based upon its morphological traits,B. corneolusis close toB. gerberaeandB. paracorneolus, and is distinguished from these species by its spicule morphology, female tail morphology and female post-uterine sac length. However, male specimens ofB. corneoluswere not available for the present study and confirmation is necessary.Bursaphelenchus elytrusis similar toB. tusciaeand is distinguished from it by its spicule (condylus) morphology and excretory pore position.Bursaphelenchus newmexicanusis close toB. glochisand is distinguished from it mostly by morphometrics and spicule (condylus) morphology. However, morphometrics usually vary among individuals and populations of a species, necessitating morphometric and molecular comparisons of more isolates (strains) in order to clarify specific status.

Philometra johnii sp. nov. (Nematoda, Philometridae), a new gonad-infecting philometrid from the sin croaker Johnius dussumieri (Cuvier) (Perciformes, Sciaenidae) from marine waters of Iraq

A new nematode species, Philometra johnii sp. nov. (Philometridae), is described from male and female specimens found in the ovary of the sin croaker, Johnius dussumieri (Cuvier) (Perciformes, Sciaenidae), in the Arabian Gulf, off the southern coast of Iraq. Based on light and scanning electron microscopical examination, the new species differs from all other gonad-infecting Philometra spp. with dorsal lamella-like structures on the distal tip of the gubernaculum in having a dorsal bipartite protuberance formed by two subdorsal lamellated parts separated from each other by a smooth longitudinal field. This gubernaculum structure is unique among all philometrids. Other distinguishing features include the structure of the male tail, number (6 pairs) and arrangement of genital papillae and the length of spicules (102-153 μm). From eight congeneric, gonad-infecting species with unknown males, the new species can be distinguished by some morphological and biometrical features found in gravid females (absence of caudal projections, length of oesophagus, moderately developed anterior oesophageal inflation, length of first-stage larvae) by the host type (fish family) and geographical distribution. Philometra johnii sp. nov. is the fourth known philometrid species recorded from marine waters of Iraq.

A New Gonad-Infecting Species ofPhilometra(Nematoda: Philometridae) from the Atlantic Spanish MackerelScomberomorus maculatus(Scombridae) off the Atlantic Coast of Florida and South Carolina

A new nematode species, Philometra atlantica n. sp. (Philometridae), is described from male and female specimens found in the ovary of the Atlantic Spanish mackerel, Scomberomorus maculatus (Mitchill) (Scombridae, Perciformes), off the Atlantic coast of Florida and South Carolina. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in the length of spicules (111-126 μm), number and arrangement of genital papillae, and a U-shaped, dorsally interrupted caudal mound in the male. A unique feature among all gonad-infecting philometrids is the presence of 2 reflexed dorsal barbs on the distal end of the gubernaculum. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by some morphological and biometrical features found in gravid females (body length, length of first-stage larvae or esophagus, structure of caudal end) and by the host type (fish family) and geographical distribution. Philometra atlantica is the fourth valid gonad-infecting species of Philometra reported from fishes of the family Scombridae.

Rhabdochona(Rhabdochona)hypsibarbin. sp. (Nematoda: Rhabdochonidae) from the Freshwater Cyprinid FishHypsibarbus wetmorei(Smith) in Northeast Thailand

A new nematode species, Rhabdochona (Rhabdochona) hypsibarbi n. sp. (Rhabdochonidae), is described from the intestine of the freshwater cyprinid fish Hypsibarbus wetmorei (Smith) in the Mekong River, Nakhon Phanom Province, northeast Thailand. It is mainly characterized by medium-sized, bifurcate deirids, the presence of 14 anterior prostomal teeth and distinct basal teeth, length ratio of the muscular and glandular portions of esophagus (1:6-9), length of the left spicule (669-774 μm), absence of a dorsal barb on the right spicule, length ratio of spicules (1:4.9-6.0), arrangement of genital papillae, and smooth eggs without filaments or swellings. In addition, specifically unidentified fourth-stage larvae of Rhabdochona (Rhabdochona) sp., morphologically similar to R. hypsibarbi, were recorded from the red-tailed tinfoil Barbonymus altus (Günther) (Cyprinidae) in the Mekong River, Nakhon Phanom Province, northeast Thailand. Rhabdochona hypsibarbi is the fourth nominal species of Rhabdochona Railliet, 1916 reported from fishes in Thailand and the second species of the nominotypical subgenus found in this country.

Description of Three Pristionchus Species (Nematoda: Diplogastridae) from Japan that Form a Cryptic Species Complex with the Model Organism P. pacificus

Three new species of Pristionchus (P. exspectatus, P. arcanus, and P. japonicus) are described from Japan. They are morphologically similar, with P. exspectatus and P. arcanus being almost indistinguishable from the model organism P. pacificus. Reproductive isolation, namely the inability to produce interfertile F1 hybrids, separates all species pairs in the species complex. Additionally, all three new species are distinguished from P. pacificus Sommer, Carta, Kim, and Sternberg, 1996 by having a gonochoristic instead of hermaphroditic mode of reproduction. In addition to its reproductive isolation, P. japonicus is distinct from other Pristionchus species by its arrangement of genital papillae. All species in the complex are separated from each other by molecular sequence divergence, as indicated by analysis of 27 nuclear protein-coding genes and unique sequences of the small subunit ribosomal RNA gene. The identification of a species complex that includes P. pacificus is invaluable for studies of population genetics, speciation, and macroevolution, particularly the evolution of hermaphroditism in the genus.

Two species of Rhabdochona (Nematoda: Rhabdochonidae) from the cyprinid fish Luciobarbus kersin (Heckel) in northern Iraq, including R. (Globochona) kurdistanensis sp. n.

A new nematode species, Rhabdochona (Globochona) kurdistanensis sp. n. (Rhabdochonidae), is decribed based on specimens collected from the intestine of the barbel Luciobarbus kersin (Heckel) (Cyprinidae) in the Greater Zab (type locality) and the Lesser Zab Rivers, Tigris River basin, Kurdistan Region, northern Iraq. It is mainly characterized by a prostom with 8 anterior teeth, the presence of basal prostomal teeth, bifurcated deirids, length ratio of the muscular and glandular portions of oesophagus (1:14.4-17.8), conspicuously short left spicule (180-204 microm), arrangement of genital papillae, nonfilamented eggs, and by having cuticular ornamentations on the tail tip (2 lateral denticular outgrowths in female and numerous fine spines in male). Description of a gravid female of Rhabdochona (Rhabdochona) sp. with 14 anterior prostomal teeth and filamented eggs, recorded from L. kersin of the Greater Zab River, is also provided. R. kurdistanensis sp. n. is the fifth valid species of Rhabdochona Railliet, 1916 and the only representative of the subgenus Globochona Moravec, 1972 recorded from Iraq.

Two new species of Rhabdochona (Nematoda: Rhabdochonidae) from freshwater fishes in Thailand

Two new species ofrhabdochonid nematodes are described from the intestine of freshwater fishes in Chiang Mai Province, northern Thailand: Rhabdochona (Rhabdochona) pseudomysti sp. n. from the catfish Pseudomystus siamensis (Regan) (Bagridae, Siluriformes) in the Fang Brook, a tributary of the Kok River (the Mekong River basin), Fang District and Rhabdochona (Globochona) thaiensis sp. n. from the cyprinid Mystacoleucus marginatus (Valenciennes) (Cyprinidae, Cypriniformes) in the Ping River (the Chao Phraya River basin), Muang District. Rhabdochona pseudomysti is mainly characterized by simple, leaf-like oval deirids (a unique feature among Rhabdochona spp.), a prostom with 14 anterior teeth, the presence of basal prostomal teeth, the length ratio of the muscular and glandular portions of oesophagus (1:2.1-2.6), an unusually long left spicule (1.10-1.22 mm), length ratio of spicules (1:11.5-14.7), arrangement of genital papillae, and conspicuously elevated vulval lips. Rhabdochona thaiensis differs from other representatives of the subgenus Globochona Moravec, 1972 possessing caudal projections on the tail tip in that it has only 2 claw-shaped projections located ventrally on the tail tip of both males and females; the species is mainly characterized by the presence of distinct pseudolabia, 8 anterior prostomal teeth, absence of basal teeth, bifurcated deirids, length ratio of the muscular and glandular portions of oesophagus (1:11.3-11.9), conspicuously short (135-141 microm) left spicule, arrangement of genital papillae, and somewhat elevated vulval lips. Fully developed eggs of R. pseudomysti and R. thaiensis remain unknown. These are the first nominal species of Rhabdochona reported from Thailand.

Oscheius amsactae n. sp. (Nematoda: Rhabditida), a necromenic associate of red-hairy caterpillar, Amsacta moori (Lepidoptera: Arctiidae) from Kanpur district, India

Oscheius amsactae n. sp. is described as a necromenic associate of red-hairy caterpillar Amsacta moori (Lepidoptera: Arctiidae) from Vigna radiata ((L.) Wilczek) cultivated field at Indian Institute of Pulses Research, Kanpur, India. This new species resembles with Rhabditis (O.) columbiana (Stock et al. 2005), however, it differs in having smaller body length (♀ L = 1100–1288 μm), lesser b value (b = 4.9–6.1), much smaller body length (c = 14–20.5), smaller spicule length (56–57 μm) and small gubernaculum length (20–27 μm), number of genital papillae and position of excretory pore. O. amsactae n. sp. can be compared with R. (O.) guentheri (Sudhaus and Hooper 1994) but differs in having a leptoderan bursa, different shape of spicule, number and arrangement of genital papillae. It also differs from R. (O.) necromena (Sudhaus and Schulte 1989) in having longer and narrower stoma and difference in shape of glottoid apparatus, smaller body length and shape of bursa. The new species closely resembles O. shamimi (Tahseen and Nisa (2006)) but differs in having narrower lip region (lip region diameter 7.1–7.9 μm vs. 11–12 μm in O. shamimi); shorter males (L = 594–804 μm vs. L = 1012 μm in O. shamimi). Moreover, the shape of spicule is also different, O. amsactae n. sp. has crochet-needle shaped tip of spicule whereas it is slightly curved in O. shamimi. Bursa is leptoderan in O. amsactae n. sp. whereas it is pseudopeloderan in O. shamimi. Additionally, molecular characterisation and electron microscopic studies confirm that it is distinctive from other species of the genus and it is a new species.

A new gonad-infecting species of Philometra (Nematoda: Philometridae) from the red cusk-eel Genypterus chilensis (Osteichthyes: Ophidiidae) off Chile

A new nematode species, Philometra genypteri sp. n. (Philometridae), is described from male and female specimens found in the ovary of red cusk-eel, Genypterus chilensis (Guichenot) (Ophidiidae, Ophidiiformes), from the eastern South Pacific Ocean off the coast of northern Chile. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in the length of spicules (126-135μm), a gubernaculum with dorsal lamella-like structures on its distal end, and the number and arrangement of genital papillae in the male. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by some morphological and biometrical features found in gravid female (absence of caudal projections, length of first-stage larvae or oesophagus, moderately developed anterior oesophageal inflation) and by the host type (fish family) and geographical distribution. P. genypteri is the first philometrid species reported from a fish belonging to the order Ophidiiformes and the second nominal species of Philometra recorded from marine fishes of the eastern South Pacific.

Mexiconema africanum sp. n. (Nematoda: Daniconematidae) from the catfish Auchenoglanis occidentalis from Lake Turkana, Kenya

A new species of dracunculoid nematode, Mexiconema africanum sp. n. (Daniconematidae), is described from the abdominal cavity and the intestine (rarely also the gall bladder) of the catfish Auchenoglanis occidentalis (Valenciennes) (Claroteidae, Siluriformes) from Lake Turkana, Kenya. The new species differs from two other congeners mainly in the absence of two large cell nuclei in the glandular oesophagus, presence of well-developed lateral cephalic elevations, more numerous (14) cephalic papillae and a much longer body of the gravid female (18-22 mm); from Mexiconema cichlasomae Moravec, Vidal and Salgado Maldonado, 1992 also in less numerous (two) caudal processes and a different arrangement of genital papillae in the male. M. africanum is the first representative of the dracunculoid family Daniconematidae described from Africa.

An emendation of the genus Teratorhabditis (Osche, 1952) Dougherty, 1953 and description of Teratorhabditis stiannula n.sp. (Rhabditidae:Nematoda)

A new bisexual species of Teratorhabditis, Teratorhabditis stiannula n.sp., from Canada is described and illustrated. The female is monodelphic, the cuticle composed externally of minute plaques, metarhabdions vary in form and have a verrucose or crenulate margin, and the tail is conoid-attenuate. Main characters of the male are a large, protuberant precloacal lip containing a copulatory cement gland duct, a peloderan bursa with u 2 () 4 + 1 + 3 arrangement of genital papillae, of which 7 open al the margin, and linear spicules, 40–48 μm long, which are fused distally along a fifth of their length. A duct-like canal opening on the anterior surface of the basal esophageal bulb is reported for the first lime. The generic diagnosis of Teratorhabditis is emended to include new characters that clarify relation ships of six recognized species and Teratorhabditis rovinjensis Sudhaus. 1974 is proposed as a new combination for Rhabditis (Teratorhabditis) rovinjensis Sudhaus, 1974.