Integrated evidence reveals a new species of Cosmocerca (Ascaridomorpha: Cosmocercoidea) from the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura).

Species of Cosmocerca Diesing, 1861 (Ascaridomorpha: Cosmocercoidea), are common nematode parasites of amphibians. In the present study, a new species of Cosmocerca, namely C. simile n. sp., was described using light and scanning electron microscopy, and sequencing different nuclear and mitochondrial genetic markers (i.e. small ribosomal DNA (18S), large ribosomal DNA (28S), internal transcribed spacer (ITS) and cytochrome c oxidase subunit 1 (cox1)). Cosmocerca simile n. sp. differs from its congeners based on body size, morphology and number of plectanes, relative length of spicules and gubernaculum and spicules to total body length and morphology and length of tail. Molecular analysis showed no nucleotide polymorphisms among different individuals of the new species regarding nuclear DNA. Very low intraspecific nucleotide variation (0.52-0.78%) was detected in cox1 mtDNA. In contrast, the level of interspecific nucleotide variation between C. simile n. sp. and its congeners were distinctly higher (2.74-18.1% in the partial ITS region and 10.2-13.5% in the partial cox1 region, respectively) than that of intraspecific variation. Phylogenetic analyses using maximum likelihood (ML) inference based on the partial ITS and cox1 sequence data both supported the new species to be a member of the genus Cosmocerca, and formed a sister relationship to C. japonica. The newly obtained genetic data are important for further studies of DNA-based taxonomy, population genetics and phylogenetics of the Cosmocercoidea.

A new Cosmocercoides species (Ascaridida: Cosmocercidae), C. wuyiensis n. sp., from the Asiatic frog Amolops wuyiensis (Amphibia: Anura).

We identified and characterized a new cosmocercid nematode species, Cosmocercoides wuyiensis n. sp., through microscopic examination and sequencing of the partial small ribosomal RNA gene (18S rDNA), internal transcribed spacer (ITS) and mitochondrial cytochrome c oxidase subunit 1 (COI) genes. The new species was isolated from the intestine of the Asiatic frog Amolops wuyiensis Liu and Hu, 1975 captured from four localities of the Anhui province in south-east China. Among the 25 recorded species of the Cosmocercoides genus, the morphology of C. wuyiensis n. sp. is closest to that of C. kiliwai and C. malayensis, which were isolated from various Mexican frog and Malaysian lizard species, respectively. However, C. wuyiensis n. sp. displayed several distinguishing features, such as small size of the male body, two spicules of unequal lengths in the male, small gubernaculum, pre-, ad- and post-cloacal caudal rosette papillae in the ratio of 18-24:2:6 and simple papillae in the ratio of 14:multiple:4, circle and number of punctation in each rosette at 1:11-16, sharply conical tail-end and the presence of lateral alae and somatic papillae in both sexes. BLAST and the phylogenetic analyses of the 18S rDNA and ITS sequences indicated that C. wuyiensis n. sp. belonged to the genus Cosmocercoides, while that of the COI gene sequence of C. wuyiensis n. sp. showed 16.36% nucleotide divergence with C. pulcher and 47.99% nucleotide divergence with C. qingtianensis. The morphological and molecular characterization of C. wuyiensis n. sp. provides new taxonomic data for this genus.

Redescription of Cruzia americana Maplestone, 1930 (Nematoda: Kathlaniidae) a parasite of Didelphis virginiana (Kerr) (Mammalia: Didelphidae) in the USA.

Cruzia americana Maplestone, 1930 is a common nematode parasite of opossums in North America. However, our present knowledge on the morphology of this species is still limited and its validity is uncertain. In the present study, specimens of C. americana collected from the type-host Didelphis virginiana (Kerr) (Mammalia: Didelphidae) in the USA were studied using light microscopy and, for the first time, scanning electron microscopy (SEM). The SEM observations revealed the internal structures of the pharynx of C. americana and the presence of pharyngeal lamellae rather than pharyngeal teeth/tooth-like structures. In addition, the detailed morphology of the lips, vulva, eggs and phasmids in females and the caudal papillae in males are also reported for the first time.

Redescription of three species of nematodes (Nematoda) parasitising fishes in the USA, with a key to the species of Dichelyne Jägerskiöld, 1902 parasitic in freshwater and brackish-water fishes of North America.

Three species of parasitic nematodes are redescribed based on light and scanning electron microscopical (SEM) examinations of newly collected specimens in fishes of South Carolina, USA: Dichelyne (Cucullanellus) bullocki Stromberg & Crites, 1972 from Fundulus heteroclitus (Linnaeus) (Fundulidae); Dichelyne (Dichelyne) diplocaecum Chandler, 1935 from Ictalurus furcatus (Valenciennes) (Ictaluridae); and Hysterothylacium pelagicum Deardorff & Overstreet, 1982 from Coryphaena hippurus Linnaeus (Coryphaenidae). For the first time, intraspecific variations in the number of intestinal caeca were observed in D. bullocki, as well as previously unknown males and gravid females of D. diplocaecum are described; this enabled to synonymise D. mexicanus Caspeta-Mandujano, Moravec & Salgado-Maldonado, 1999 with D. diplocaecum. Unlike most congeneric species, H. pelagicum has no double postanal papillae, as confirmed by SEM. A key to the species of Dichelyne Jägerskiöld, 1902 parasitic in freshwater and brackish-water fishes in North America is provided.

Dichelyne (Cucullanellus) bodiani n. sp. and Cucullanus hansoni Olsen, 1952 (Nematoda: Cucullanidae) from fishes off New Caledonia.

Two species of cucullanid nematodes collected from the intestine of marine fishes off New Caledonia were studied with the use of light and scanning electron microscopy (SEM): Dichelyne (Cucullanellus) bodiani n. sp. from Bodianus perditio (Quoy & Gaimard) (Perciformes: Labridae), characterised mainly by the small size of the body (males and gravid females 2.26-3.13 mm and 2.46-3.32 mm long, respectively), the presence of very long spicules (1.53-1.66 mm in length), the remarkably large seminal vesicle and the arrangement of caudal papillae, is the second known species of Dichelyne Jägerskiöld, 1902 parasitising fishes of the Labridae and the second nominal species of this genus recorded from fishes in New Caledonian waters. Cucullanus hansoni Olsen, 1952, originally described from Hawaii, is now, after 67 years, again reported from its type-host, Sufflamen fraenatum (Latreille) (Tetraodontiformes: Balistidae), from off New Caledonia. The SEM examination of C. hansoni, used in this species for the first time, revealed some new morphological details, such as the presence of a median precloacal cuticular elevation or the shape of deirids and distal tips of spicules, as well as the exact location of caudal papillae and phasmids in the male. This is the seventh species of Cucullanus Müller, 1777 recorded from fishes off New Caledonia.

Morphological and molecular evidence for a new species of the genus Cosmocercoides Wilkie, 1930 (Ascaridida: Cosmocercidae) from the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura).

A new cosmocercid species, Cosmocercoides qingtianensis sp. n., collected from the intestine of the Asiatic toad Bufo gargarizans Cantor (Amphibia: Anura) is described using integrated approaches, including light and scanning electron microscopy, and sequencing and analyzing the ribosomal [small ribosomal DNA (18S) and internal transcribed spacer (ITS)] and mitochondrial [cytochrome c oxidase subunit 1 (cox1)] target regions, respectively. The new species can be distinguished from its congeners by the combination of the following morphological characters, including the large body size, the presence of lateral alae and somatic papillae in both sexes, the length of spicules, the particular morphology and length of gubernaculum, the number, arrangement and morphology of caudal rosettes, the presence of large medioventral precloacal papilla and the long tail. Our molecular analysis revealed the level of intraspecific genetic variation of C. qingtianensis sp. n. distinctly lower than that of the interspecific genetic variation in the ITS and cox1 regions. However, there are some overlaps in the range of intra- and interspecific 18S sequence divergence between the new species and some closely related species. The results of molecular analysis supported the validity of the new species based on the morphological observations. The 18S, ITS, and cox1 regions of C. pulcher collected from Bufo japonicus formosus in Japan were also sequenced and analyzed. The results showed a low level of intraspecific genetic variation in 18S and ITS regions (0-0.12% and 0-0.23% nucleotide differences, respectively), but a relatively high level of intraspecific genetic variation in cox1 region (0.78-4.69% nucleotide differences). In addition, it seems more powerful and practical to use the cox1 region as a genetic marker for the accurate identification and differentiation of species of Cosmocercoides than the 18S and ITS regions, especially for the closely related species.

Morphological and molecular characterization of Megalobatrachonema hainanensis sp. nov. (Nematoda: Ascaridida), with phylogenetic position of Megalobatrachonema in Cosmocercoidea.

The genus Megalobatrachonema is a rare group of nematode parasites within Ascaridida. The systematic status of Megalobatrachonema in the superfamily Cosmocercoidea (Ascaridida) has long been controversial. The relationship of Megalobatrachonema and Chabaudgolvania remains unsolved. In the present study, a new species of Megalobatrachonema, M. hainanensis sp. nov., was described based on specimens collected in Amolops hainanensis (Boulenger) and Hylarana spinulosa (Smith) (Amphibia: Anura) from Hainan Island, China. The large ribosomal DNA (28S) and internal transcribed spacer (ITS1-5.8S-ITS2) were also sequenced for molecular identification and phylogenetic study. Phylogenetic analyses using maximum likelihood (ML) inference and Bayesian inference (BI) based on 28S and ITS1 sequence data, respectively, supported that Megalobatrachonema is a member of the family Kathlaniidae. In addition, the genetic comparison and phylogenetic results based on ITS1 sequence data also supported that the genus Chabaudgolvania should be considered as a synonym of Megalobatrachonema.

Neocosmocercella fisherae n. sp. (Nematoda: Cosmocercidae), a parasite of the large intestine of Phyllomedusa bicolor (Boddaert) (Anura: Phyllomedusidae) from the Brazilian Amazon.

Neocosmocercella fisherae n. sp. is the first nematode species found parasitising Phyllomedusa bicolor from the Brazilian Amazon Region. The new species has a triangular oral opening, with bi-lobed lips, and is distinguished from N. bakeri (triangular oral opening with simple lips), and from N. paraguayensis (hexagonal oral opening with bi-lobed lips). Additionally, the new species has ciliated cephalic papillae, which are absent in the other species of the genus. The reduced uterine sac and the presence of a single egg in the uterus in females are the main morphological characters that differentiate the new species from its congeners N. bakeri (8-10 eggs) and N. paraguayensis (10 eggs, based on the allotype). Additionally, the new species differs from the other two species of the genus by morphometric characters such as the size of spicules and gubernaculum in males and the vagina in females. Until now, phyllomedusid anurans are the only known hosts for the nematodes of this genus. The present work describes the third species of the genus and the first species of nematode parasitising P. bicolor.

Redescription of Maupasina weissi (Seurat, 1913) (Nematoda: Ascaridida) from sengis, Elephantulus spp. and Macroscelides proboscideus (Shaw) (Macroscelidea), in Africa.

Maupasina weissi (Seurat, 1913), is redescribed from the eastern rock sengi, Elephantulus myurus Thomas & Schwann, from Limpopo Province and compared with material collected from Free State and North West Provinces, South Africa, as well as the description of the type-material from South Tunisia. Distinguishing features of the species include a corona radiata of 12 pointed leaflike elements, a complex bipartite buccal capsule with 3 large bicuspid denticular lobes and 4 smaller club-shaped lobes and 11 (occasionally 10) pairs of cloacal papillae in the male. The complex taxonomic history of the genus Maupasina Seurat, 1917 is discussed. The probable misidentification of Macroscelides proboscideus Shaw, the short eared sengi, from North West Province, South Africa, as a host of M. weissi is explained, indicating that M. weissi occurs only in species of the genus Elephantulus Thomas & Schwann. The widely separated geographical regions, stretching the length of the African continent, in which M. weissi has been found are indicative of a conservative species with a broad geographical distribution. Tenebrionid beetles, up to 50% of stomach contents of E. myurus in Limpopo Province may act as intermediate hosts in the life-cycle of M. weissi.

Morphological and molecular evidence for a new species of Pseudanisakis Layman & Borovkova, 1926 (Nematoda: Ascaridida), parasitizing Rajiformes in southern Southwest Atlantic waters.

Pseudanisakis argentinensis n. sp. is proposed to accommodate parasitic nematodes found in six skate species (Rajidae and Arhynchobatidae) examined from southern Southwest Atlantic waters. The new species differs from its congeners by the following combination of characters: a cupola on each lip, males with 8-12 pairs of precloacal genital papillae, a larger size for both males and females, a greater length-to-breadth ratio of the ventriculus and the presence of a small knob on the tip of the tail. Allometric growth was observed for several morphometric features; however, the slopes of the allometric relationships across host species exhibited non-significant differences and were considered as a strong evidence for conspecificity. Congruent results were obtained after the genetic characterization of the mitochondrial cytochrome c oxidase subunit 1 gene of worms obtained from different skate species, whose values of genetic divergence (1.3) lay within the range of intraspecific variation. Previous records of specimens referred to as Pseudanisakis tricupola in skates from South American waters are regarded as conspecific with P. argentinensis n. sp.

Two new species of nematode parasites, Cucullanus epinepheli sp. n. (Cucullanidae) and Procamallanus (Spirocamallanus) sinespinis sp. n. (Camallanidae), from marine serranid and haemulid fishes off New Caledonia.

Based on light and scanning electron microscopical studies, two new species of parasitic nematodes are described from marine perciform fishes off New Caledonia: Cucullanus epinepheli sp. n. (Cucullanidae) from the intestine of the brownspotted grouper Epinephelus chlorostigma (Valenciennes) (Serranidae) and Procamallanus (Spirocamallanus) sinespinis sp. n. from the intestine of the silver grunt Pomadasys argenteus (Forsskål) (Haemulidae). Cucullanus epinepheli sp. n. differs from its congeners mainly in possessing a unique structure of the anterior, elevated cloacal lip with a large posterior outgrowth covering the cloacal aperture and in the presence of cervical alae and two small preanal papillae on the median dome-shaped precloacal elevation. This is the second known nominal species of this genus parasitising fishes of the family Serranidae and the second representative of Cucullanus Müller, 1777 recorded from fishes in New Caledonian waters. Procamallanus (Spirocamallanus) sinespinis sp. n. is mainly characterised by 10-12 spiral ridges in the buccal capsule, the presence of wide caudal alae, three pairs of pedunculate preanal papillae, two unequally long spicules (465-525 µm and 218-231 µm) and by the tail tip with a knob-like structure in the male, and the broad, rounded tail with a terminal digit-like protrusion without cuticular spikes in the female. This is the fifth nominal species of the subgenus Spirocamallanus Olsen, 1952 reported from fishes in New Caledonian waters.

Morphological and molecular analyses of the spiruroid nematode, Falcaustra araxiana Massino, 1924 (= Spironoura araxiana) from the European pond turtle (Emys orbicularis).

There is little information on the phylogenetic position and life cycle of family Kathlaniidae. Falcaustra araxiana is a member of this family which infects the large intestine of the European pond turtle (Emys orbicularis). In the present study, morphological data and molecular analyses based on the 18S rDNA were performed on different types of F. araxiana originating from the large intestine and gastric nodules in the turtle. Morphological data revealed both larvae and adult stages in the gastric nodules. In addition, all nematodes recovered in the large intestine were adult worms. GenBank accession numbers KM200715 and KM200716 were provided for adult F. araxiana located in the intestine and stomach, respectively, of E. orbicularis. The results of sequencing proved that these two types are completely similar. Accordingly, it can be hypothesized that nodule formation is a part of the life cycle of the parasite or a survival strategy. Furthermore, F. araxiana develops to the adult stage in the gastric mucosa prior to migrating to the large intestine. Phylogenetic analysis revealed that F. araxiana unexpectedly branched away from other members of the superfamily Seuratoidea (Truttaedacnitis truttae, Cucullanus robustus and C. baylisi) and showed a closer relationship with Paraquimperia africana, a member of the Ascaridoidea. It seems that phylogenetic reconstruction for the present parasite needs more detailed morphology, life cycle and molecular studies.

A new species of Neocosmocercella Baker & Vaucher, 1983 (Nematoda: Cosmocercidae), a parasite of Phyllomedusa vaillantii Boulenger (Anura: Phyllomedusidae) in the Caxiuanã National Forest, eastern Amazon, Brazil.

Neocosmocercella bakeri n. sp. is described from the large intestine of Phyllomedusa vaillantii Boulenger collected in the Caxiuanã National Forest in the Eastern Brazilian Amazon. The new species is easily distinguished from the type-species of the genus, Neocosmocercella paraguayensis Baker & Vaucher, 1983 in possessing a triangular mouth opening with three simple lips (vs three bi-lobed lips and hexagonal mouth opening) and somatic papillae, which are absent in N. paraguayensis. The males of the new species are distinguished by the distribution of the sessile cloacal papillae and the dimensions of the gubernaculum, whereas the females are distinguished by their smaller size and opisthodelphic uterus. This study expands the diagnostic characters of Neocosmocercella Baker & Vaucher, 1983, reports the first species parasitising anurans of the Brazilian Amazon, a new host record for the genus, and the description of the second species of the genus.

Ingwenascaris n. g. (Nematoda: Ascaridida: Heterocheilidae) established for I. sprenti n. sp. and I. assymmetrica (Ortlepp, 1932) n. comb., parasites of African crocodiles, and an identification key to the genera of the Heterocheilidae.

Ingwenascaris n. g. (Nematoda: Heterocheilidae) is established to accommodate Ingwenascaris sprenti n. g., n. sp., described from the stomach of Crocodylus niloticus Laurenti (Reptilia: Crocodylidae) in South Africa, based on light and scanning electron microscopy studies of its morphology. The new genus can be distinguished from other heterocheilid genera through a combination of its characters, including the pronounced asymmetry of each subventral lip due to an alate ventral margin and a non-alate margin facing the dorsal lip, the presence of continuous ridges of triangular denticles along the free labial margins, the lack of interlocking processes or a rostral plate, interlabia being indistinct or represented by small lateral interlabia between the dorsal and ventral lips only, the absence of prominent interlabial longitudinal cuticular ridges, the presence of lateral alae that are fused with the subventral lips, the presence of lateral caudal alae in both sexes, spicules of males that are composed of handle and alate blade, the presence of a gubernaculum, the number and arrangement of male caudal papillae and the position of the vulva near the anterior and middle third of the body in females. Ingwenascaris sprenti n. g., n. sp. represents the sixth heterocheilid genus parasitising African crocodilians. Trispiculascaris assymmetrica (Ortlepp, 1932) (syn. Porrocaecum assymmetricum Ortlepp, 1932) from a Central African crocodile is transferred to the new genus as I. assymmetrica (Ortlepp, 1932) n. comb. The genus Trispiculascaris Skrjabin, 1916 is considered a genus incertae sedis. An identification key to the genera of the family Heterocheilidae is presented.

Typhlophoros kwenae n. sp. (Nematoda: Ascaridida: Heterocheilidae), a gastric parasite from the Nile crocodile Crocodylus niloticus Laurenti (Reptilia: Crocodylidae) in South Africa.

Based on light and scanning electron microscopical observations, Typhlophoros kwenae n. sp. (Heterocheilidae), a new nematode parasite, is described from the stomach of the Nile crocodile Crocodylus niloticus Laurenti in South Africa. In having three lips with well-developed posterior prolongations and prominent interlabial longitudinal cuticular ridges, four pairs of precloacal papillae and complex spicules divided into handle and broad alate blade in males, as well as the position of the vulva near mid-body in females, the specimens conform to the generic diagnosis of Typhlophoros von Linstow, 1906. They can, however, be distinguished from the two previously described congeners, T. lamellaris von Linstow, 1906 and T. spratti Sprent, 1999, by the number of complete interlabial ridges, the length of spicules in males and the position of the vulva as well as the length of the tail in females. This is the first record of the genus Typhlophoros from the Afrotropical Realm.

Morphological and molecular genetic diversity of Strongyluris calotis (Nematoda: Ascaridida: Heterakidae) in South East and East Asian lizards.

Strongyluris calotis is a heterakid nematode in the large intestine of agamid lizards (Reptilia: Sauria: Agamidae) from the Oriental Region. The standard light microscopic definition of the species counts the "caudal papillae" as 10 pairs on male worms. However, previous work from our group using scanning electron microscopy (SEM) on the heterakid from agamid lizards in Japan, Taiwan, and Singapore revealed that this counting contained a pair of phasmids and that two pairs of postcloacal papillae were completely fused to form a pair of united papillae, thus resulting in "10 pairs." In the present study, we examined S. calotis specimens from the Emma Gray's forest lizard, Calotes emma (Agamidae), living in the plain forest at low altitude, and the Vietnam false bloodsucker, Pseudocalotes brevipes (Agamidae), living in the mountainous forest at high altitude in the northern part of Vietnam. Using SEM, the arrangement of caudal papillae in male worms from an Emma Gray's forest lizard was found to be comparable to classical S. calotis specimens from agamid lizards collected in Japan, Taiwan, and Singapore. However, male worms from Vietnam false bloodsuckers did not have a pair of united papillae but had 10 pairs of independent caudal papillae with a pair of phasmids. Molecular genetic analyses of the ribosomal RNA gene (rDNA) of worms of the classical S. calotis morphotype from Japan and Singapore and two S. calotis morphotypes from Vietnam demonstrated absolutely identical nucleotide sequences of partial 18S rDNA (at least 1764 base pairs (bp)) and 5.8S rDNA (158 bp). However, intraspecific differences were detected in other regions of the rDNA, related to the geographical distribution of hosts regardless of morphotype: 97.8-98.5 % identity (443-446 bp/453 bp) in the internal transcribed spacer (ITS)-1 region, 96.6-98.0 % identity (425-431 bp/440 bp) in the ITS-2 region, and 99.6-99.7 % identity (1149-1151 bp/1154 bp) in the 28S rDNA. Thus, in the future, taxonomic relationships of S. calotis distributed widely in the Oriental Region as well as other nominal Oriental Strongyluris spp., currently six in number, need to be extensively explored based on molecular genetic analyses in addition to intensive morphological characterization.

Morphological study of Ophidascaris excavata Hsü & Hoeppli, 1931 (Ascaridida: Ascarididae) from Gloydius brevicaudus (Stejneger) (Reptilia: Viperidae).

Ophidascaris excavata Hsü & Hoeppli, 1931 is a poorly known ascaridid parasite reported from the short-tailed pit viper Gloydius brevicaudus (Stejneger) (Reptilia: Viperidae) in China. In the present paper, the detailed morphology of this nematode was studied using light and scanning electron microscopy (SEM) based on newly collected material. The results revealed several important, but previously unreported, morphological features, including the presence of one pair of small, finger-like prolongations on each lip, narrow cervical alae beginning well posterior to the base of the ventrolateral lips and the second pair of postcloacal ventro-lateral papillae being double; in addition, there is no intestinal caecum. These supplementary morphological and morphometric data, especially the detailed morphological features obtained herein under SEM, would help us to understand the relationships of O. excavata with its congeners and enable us to diagnose this species more accurately.

Dujardinascaris gigantea sp. n. (Nematoda: Ascaridida) from the critically endangered crocodile Alligator sinensis Fauvel (Reptilia: Crocodylia).

The Chinese alligator Alligator sinensis Fauvel (Reptilia: Crocodylia) is considered as one of the most critically endangered species of the 23 extant crocodiles. However, our knowledge of the helminth parasites of this rare animal is completely lacking. During a helminthological survey of reptiles in China, we found a new ascaridoid nematode, Dujardinascaris gigantea sp. n. from A. sinensis. The morphology of D. gigantea sp. n. was studied using light and scanning electron microscopy. The new species was also characterised using molecular methods by sequencing and analysing the small ribosomal DNA (18S) and the second internal transcribed spacer (ITS-2).

New species of Cucullanus (Nematoda: Cucullanidae), an intestinal parasite of the peacock bass Cichla piquiti (Perciformes: Cichlidae) from the Tocantins River, Brazil.

Cucullanus tucunarensis n. sp. (Cucullanidae) is described parasitizing the peacock bass Cichla piquiti (Cichlidae) from the Tocantins River, Tocantins State, Brazil. The new species is unique and differs from all its congeners by having a tail tip provided with several sclerotized spine-like processes on its ventral side, present in both the male and female. Furthermore, C. tucunarensis n. sp. is compared with other species of the genus recorded in the same zoogeographical region and in the same group of hosts (Perciformes).

Subulura halli (Ascaridida: Subuluridae) from the endangered great bustard Otis tarda Linnaeus (Aves: Gruiformes) in China.

Subulurid nematodes identified as Subulura halli Barreto, 1918 were collected from the endangered bird Otis tarda Linnaeus (Gruiformes: Otididae) in China. A detailed redescription of the hitherto poorly known species is presented using both light and, for the first time, scanning electron microscopy. Previously unreported and erroneous morphological features of taxonomic significance are revealed. This species can be readily distinguished from its congeners by the relatively long oesophagus (1.47-1.92 mm long, representing 10.6-16.9% of body length), the number and arrangement of male caudal papillae (11 pairs in total, arranged as five pairs of precloacal and six pairs of postcloacal papillae), the equal length of spicules (1.35-1.52 mm long, representing 10.7-13.7% of body length) and the presence of a small medioventral, precloacal papilla in the male.