Short Spicules Research Articles

Comparative study on CT image characteristics of pneumoconiosis large shadow and primary lung cancer mass

Objective: To compare the CT image characteristics of pneumoconiosis large shadow and primary lung cancer mass, and analyze the value of CT image characteristics in the differential diagnosis of pneumoconiosis large shadow and primary lung cancer. Methods: In September 2022, 43 patients with stage Ⅲ pneumoconiosis who were hospitalized in Zibo Occupational Disease Prevention Hospital from January 2020 to June 2021 and 52 patients with primary lung cancer who were confirmed by pathology in the Affiliated Hospital of Jining Medical University during the same period were selected as the investigation objects, and the image characteristics of pneumoconiosis large shadow or lung cancer mass and surrounding tissues in the chest CT images of the two groups were compared. Univariate analysis, cluster analysis and cross analysis were used to screen out statistically significant indicators as independent variables, and pneumoconiosis and lung cancer as dependent variables for logistic regression analysis. Results: There were statistically significant differences between large shadow of pneumoconiosis and primary lung cancer mass in single factor CT imaging, such as irregular shape of lesions, CT attenuation value, calcification, cavitation, spiculation, liquefactive necrosis, satellite lesions, adjacent emphysema, short spicules, and pleural thickening (P<0.05). CT value ≥92 HU (abnormal CT attenuation value), calcification, peripheral satellite lesions, pleural thickening, parapunctal emphysema, spines on the lesion margin, irregular lesion morphology were typical features of stage Ⅲ pneumoconiosis, with multiple features of aggregation. The typical features of lung cancer were liquefaction necrosis, round or quasi-round appearance, cavitation and interlobar pleura. A logistic regression model was constructed using satellite lesions, spiculation, pleural thickening, and lesion abnormal CT attenuation value had an R(2) of 0.880 and an accuracy of 95.3% for differentiation. Conclusion: Abnormal CT attenuation value, calcification, peripheral satellite lesions, pleural thickening, spiculation at the edges, liquefaction necrosis, interlobar pleura involvement, and cavitation can distinguish the large shadow of stage Ⅲ pneumoconiosis from lung cancer mass.

MINISIGMA VIETNAMICUM gen. nov., sp. n. И HOFMAENNERIA LONGISETOSA sp. n. (NEMATODA, CHROMADOREA) С КОРАЛЛОВЫХ РИФОВ ВО ВЬЕТНАМЕ

One genus and two new for science nematoda species, found in coral reefs of coast area of Vietnam are described. Minisigma gen. nov. characterized by the finely annulated cuticle with lateral files in the form of two parallel sclerotized ridges. At both edges of lateral files there are cuticular pores. Pharyngostoma armed with large dorsal tooth and two small subventral teeth. The fovea of amphids in the form double-turn spirals. There are ocellius. Pharynx bulb elongate-oval, poorly expressed. In front of cloaca four S-shaped sclerotized supplements. Minisigma vietnamicum gen. nov., sp. n. is described and illustrated Hofmaenneria longisetosa sp. n. in body size is close to H. keoladensis Khan, Husain, Sultana, 2005 and H. niddensis Gerlach, Meyl, 1957. It differs from first species by relatively shorter pharynx, relatively shorter tail, longer outer labial setae. It differs from second species by thinner body, relatively shorter tail, longer outer labial setae and shorter spicules.

Two new species of the order Monhysterida (Nematoda) from the sea of China.

Two new marine nematode species belonging to the order Monhysterida are described from the sea of China. Halomonhysterazhangisp. nov. is characterized by its relatively small body size; short anterior sensory setae; small, circular amphidial fovea located at the level of buccal cavity base; funnel-shaped buccal cavity; an excretory-secretory system with a large ventral gland and opening as a very narrow canal just posterior to the level of cephalic setae; slightly curved slender spicules with cephalated proximal end and tapered distal end; rod-like gubernaculum without apophysis; two papilliform precloacal supplements just in front of the cloaca; conico-cylindrical tail with two ventral papillae, each with a seta; and distance between the vulva and anus slightly longer than the tail length. This is the first new species of epiphytic nematode reported in China. The second new species, Stylotheristusflagellicaudatussp. nov., has a relatively shorter body and longer tail; striated cuticle; The anterior sensilla arranged in two circles, the first circle consisting of six inner labial setiform papillae (3-4 µm) and the second circle consisting of 16 long setae (12-19 µm); a transversely oval amphideal fovea; a well-developed muscle around the funnel-shaped buccal cavity; short spicules and a gubernaculum composed of a single piece; and precloacal supplements absent. An updated key to all species of Halomonhystera and pictorial key to all species of Stylotheristus are also given.

Oxysomatium brevispiculum n. sp. (Nematoda: Cosmocercidae) from Amphisbaena alba Linnaeus (Squamata, Amphisbaenidae) in the Cerrado Biome from Brazil.

In the present study, we describe Oxysomatium brevispiculum n. sp. (Ascaridida: Cosmocercidae) parasitizing Amphisbaena alba Linnaeus (Squamata: Amphisbaenidae) in the municipality of Uberlândia, Cerrado Biome, Minas Gerais, Brazil. Oxysomatium brevispiculum n. sp. differs from its congeners by having shorter spicules and by the number and arrangement of caudal papillae. The males of thenew species have a precloacal unpaired papilla and can be easily distinguished from O. caucasicum in which this morphological trait is absent. Oxysomatium brevispiculum n. sp. differs from the other three species of the genus by thenumber and arrangement of caudal papillae, with 13 pairs + 1 unpaired precloacal papilla, arrangement 8+1:2:3, while O. brevicaudatum has 14-16 pairs +1 unpaired papilla, and 7-9+1:1:6 arrangement, O. petrolinensis has 16 pairs +1 unpaired papilla, and 8+1:1:7 arrangement, and O. dollfusi with 15-16 pairs +1 unpaired papilla, and 8-9+1:1:6 arrangement. Oxysomatium brevispiculum n. sp. is the fifth species of this genus, the second species in a Neotropical host, and the first species of this genus described in amphisbaenid hosts. In addition, the present study provides an identification key for the species of this genus.

Gastrointestinal helminths of the Australasian harrier (Circus approximans Peale, 1848) in New Zealand, and description of a new species of nematode, Procyrnea fraseri n. sp. (Habronematidae).

The Australasian harrier Circus approximans, a native of Australia, New Zealand and the South Pacific, is an opportunistic hunter of small prey, although a large part of its diet consists of carrion, mainly from roadkill. Besides a record of a single, unnamed species of capillariid nematode there have been no investigations into the parasites of Australasian harriers in New Zealand. In this study, a helminthological survey of sixty-five deceased harriers from southern New Zealand uncovered a gastrointestinal helminth fauna consisting of six parasite species. Porrocaecum circinum (Nematoda) was previously described only from fragmented females, and a redescription is presented here. Procyrnea fraseri n. sp. (Nematoda) is described, and distinguished from its congeners by its slender body shape and shorter spicules. Strigea falconis (Trematoda) is reported for the first time in New Zealand. Cladotaenia anomalis (Cestoda) and Polymorphus circi (Acanthocephala) were previously described as new species elsewhere. An unnamed species of capillariid appears to be mainly confined to North Island and is rare in South Island. Prevalence and intensity metrics are given, and DNA sequences provided to accompany new re/descriptions. Potential intermediate hosts are discussed, and the origins of the helminths and their potential for pathogenicity are considered.

Corononema vulgare sp. n. and Hofmaenneria coralis sp. n. (Nematoda, Monhysterida) from coral reefs off the coast of Vietnam.

Two new nematode species of the order Monhysterida, found in coral reefs on the coast of Vietnam, are described and illustrated. Corononema vulgare sp. n. morphology is similar to C. thai Nicholas & Stewart, 1995 but differs from it by the shorter outer labial setae, shorter tail in males, and a different shape of the guiding lateral bodies in the spicular apparatus of males. Hofmaenneria coralis sp. n. morphology is close to H. niddensis Gerlach & Meyl, 1957 and H. optata Alekseev, 1983. The new species differs from the first species by having thinner body, a shorter and less slender tail, and shorter spicules. The new species differs from H. optata in having a longer body, shorter pharynx, shorter tail, and longer outer labial setae.

Arthrostoma supriatnai sp. nov. (Nematoda: Ancylostomatidae) parasitic in Mydaus javanensis (Carnivora: Mephitidae) from Mount Ciremai, Java, Indonesia.

Arthrostoma supriatnai sp. nov. was described from Mydaus javanensis obtained from Mount Ciremai, Java, Indonesia. It is characterized by having a buccal capsule with ten articulated plates including a pair of additional lateral plates. To date, the genus Arthrostoma consists of eleven species that are native to Asia. Of them, only A. miyazankiense and A. tunkanati have ten articulated plates including the lateral plates. However, the present species has a much stouter body, being readily distinguishable from these two species. Moreover, its male has much shorter spicules than A. miyazakiense, and an arrow-shaped gubernaculum, differing from A. tunkanati, in which gubernaculum is distally bifid. In the female, the present species is readily distinguished from these two species in the shape and number of vulval swellings.

Morphological and molecular characterization, including parasitic and pathogenic studies of a new spherical cyst nematode species, Globodera vulgaris n. sp. (Nematoda: Heteroderidae), associated with potatoes in China.

In this study, a new spherical cyst nematode belonging to the genus Globodera, herein described as Globodera vulgaris n. sp., was extracted from the roots and rhizosphere soil of potato and circumjacent weeds belonging to different families in three provinces in southwest China. The new species was characterized by 8-24 ridges between the anus and fenestra and an average Granek's ratio of 2.8-3.8 in cysts, a head with 3-4 annules and dorsal knob anteriorly projected and ventral knobs round or anteriorly projected in second stage juveniles, and a head with 3-5 annules, spicule short and average length less than 30.0 μm, with a developed velum in males. Pathogenicity tests showed that G. vulgaris n. sp. infected potato but did not damage or affect the potato yield compared to control, and it parasitized tomato with a low reproduction rate (RF < 1) while did not parasitize tobacco (RF = 0). The new species was close to G. rostochiensis based on molecular diagnostic marker sequences and constructed phylogenetic analysis, that is internal transcribed spacers of ribosomal DNA (ITS), large-subunit rDNA (LSU) and small-subunit rDNA (SSU). However, the new species exhibited differences from G. rostochiensis in terms of morphological characteristics, a wide host preference, lack of damage to hosts, and egg hatching rate induced by hatching factors.

METACHROMADORA (BRADYLAIMUS) TENUIS sp. n. И SPIRINIA LAEVIOIDES GERLACH, 1963 (NEMATODA, DESMODORIDA) С КОРАЛЛОВЫХ РИФОВ ВО ВЬЕТНАМЕ

Two new nematode species of the family Desmodoridae Filipjev, 1922, found in coral reefs in Vietnam, are described and illustrated. Metachromadora (Bradylaimus) tenuis sp. n. in body size and absence of precloacal supplements in males is close to M. (B.) asupplementa [Crites, 1961] and M. (B.) suecica (Allgen, 1929).&#x0D; It differs from both species by the comparatively thinner body, comparatively shorter tail, presence of bipartite basal bulb of pharynx and shorter spicules and gubernaculum [Crites, 1961]. The table of chief of morphological characters of males 12 valid species of the genus Metachromadora (Bradylaimus) is given. Spirinia laevioides Gerlach, 1963 was described from one female and two males from atoll in the Maldives. The description was short and incomplete. Since we had a lot of material available, it was decided to rewrite and reillustrate this species.

Steinernema indicum n. sp., a new entomopathogenic nematode (Nematoda: Steinernematidae) from India

Summary A new species of entomopathogenic nematode, Steinernema indicum n. sp., was isolated from a coconut palm (Cocos nucifera) field in the district of Udupi, Karnataka, India. The infective juveniles (IJ) of S. indicum n. sp. possess a body length of 1043 (869-1172) μm. The lateral fields are formed by eight equally spaced and developed ridges (nine incisures) in the mid-body region, giving the formula 3, 8, 7, 5. The excretory pore is located posterior to the mid-pharynx region (D% = 63), and the hyaline region occupies ca half of the tail length. The first-generation males are characterised by very short spicules 66 (60-70) μm long. The male spicules are moderately curved with a sharp tip and are golden-brown in colour with the manubrium elongate and with a length to width ratio of 1.92:1. There are 11 pairs of genital papillae plus a single midventral papilla located anterior to the cloacal region. The first-generation male of S. indicum n. sp. is characterised by the presence of a single dorsal postcloacal papilla, a typical diagnostic character that has not been reported from any other steinernematid species. The first-generation male tail has a short mucron present in ca 40% of specimens examined and a second-generation male tail showing a short mucron present in ca 65% of male specimens examined. The first and second-generation females possess a slightly protruding post-anal swelling. The new species is further characterised by sequences of the internal transcribed spacer (ITS) and partial 28S regions (D2-D3) of the ribosomal DNA (rDNA). Phylogenetic analyses confirm that S. indicum n. sp. belongs to the glaseri-group and, based on both ITS and D2D3 genes, showed that S. indicum n. sp. is a member of the karii clade.

Value of dual-layer spectral detector computed tomography in the diagnosis of benign/malignant solid solitary pulmonary nodules and establishment of a prediction model.

This study aimed to investigate the role of spectral detector computed tomography (SDCT) quantitative parameters and their derived quantitative parameters combined with lesion morphological information in the differential diagnosis of solid SPNs. This retrospective study included basic clinical data and SDCT images of 132 patients with pathologically confirmed SPNs (102 and 30 patients in the malignant and benign groups, respectively). The morphological signs of SPNs were evaluated and the region of interest (ROI) was delineated from the lesion to extract and calculate the relevant SDCT quantitative parameters, and standardise the process. Differences in qualitative and quantitative parameters between the groups were statistically analysed. A receiver operating characteristic (ROC) curve was constructed to evaluate the efficacy of the corresponding parameters in the diagnosis of benign and malignant SPNs. Statistically significant clinical data, CT signs and SDCT quantitative parameters were analysed using multivariate logistic regression to determine the independent risk factors for predicting benign and malignant SPNs, and the best multi-parameter regression model was established. Inter-observer repeatability was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Malignant SPNs differed from benign SPNs in terms of size, lesion morphology, short spicule sign, and vascular enrichment sign (P< 0.05). The SDCT quantitative parameters and their derived quantitative parameters of malignant SPNs (SAR40keV, SAR70keV, Δ40keV, Δ70keV, CER40keV, CER70keV, NEF40keV, NEF70keV, λ, NIC, NZeff) were significantly higher than those of benign SPNs (P< 0.05). In the subgroup analysis, most parameters could distinguish between benign and adenocarcinoma groups (SAR40keV, SAR70keV, Δ40keV, Δ70keV, CER40keV, CER70keV, NEF40keV, NEF70keV, λ, NIC, and NZeff), and between benign and squamous cell carcinoma groups (SAR40keV, SAR70keV, Δ40keV, Δ70keV, NEF40keV, NEF70keV, λ, and NIC). However, there were no significant differences between the parameters in the adenocarcinoma and squamous cell carcinoma groups. ROC curve analysis indicated that NIC, NEF70keV, and NEF40keV had higher diagnostic efficacy for differentiating benign and malignant SPNs (area under the curve [AUC]:0.869, 0.854, and 0.853, respectively), and NIC was the highest. Multivariate logistic regression analysis showed that size (OR=1.138, 95% CI 1.022-1.267, P=0.019), Δ70keV (OR=1.060, 95% CI 1.002-1.122, P=0.043), and NIC (OR=7.758, 95% CI 1.966-30.612, P=0.003) were independent risk factors for the prediction of benign and malignant SPNs. ROC curve analysis showed that the AUC of size, Δ70keV, NIC, and a combination of the three for differential diagnosis of benign and malignant SPNs were 0.636, 0.846, 0.869, and 0.903, respectively. The AUC for the combined parameters was the largest, and the sensitivity, specificity, and accuracy were 88.2%, 83.3% and 86.4%, respectively. The SDCT quantitative parameters and their derived quantitative parameters in this study exhibited satisfactory inter-observer repeatability (ICC: 0.811-0.997). SDCT quantitative parameters and their derivatives can be helpful in the differential diagnosis of benign and malignant solid SPNs. The quantitative parameter, NIC, is superior to the other relevant quantitative parameters and when NIC is combined with lesion size and Δ70keV value for comprehensive diagnosis, the efficacy could be further improved.

Steinernema shori n. sp., a new entomopathogenic nematode (Nematoda: Steinernematidae) from India.

In this study, morphological and molecular features were used to identify a new Steinernema sp. from Chhattisgarh, India. Morphological and molecular features provide evidence for placing the new species into the "bicornutum" clade. The new species is characterized by the following morphological features: infective juveniles with a body length of 587 (494-671) μm; a distance from the anterior end to excretory pore of 46 (43-50) μm; a distance from anterior end to nerve ring of 72 μm (61-85 μm); and E% of 88 (77-97). The first-generation males are characterised by 27 genital papillae and very short spicules, with a length of 61 μm (53-67) μm. The SW% and GS% ratio of S. shori n. sp. are 139 (107-190) and 75 (62-90), respectively. The new species is further characterized by sequences of the internal transcribed spacer and partial 28S regions of the ribosomal DNA. Phylogenetic analyses show that S. shori n. sp. is most closely related to S. abbasi, S. kandii, and S. yirgalemense.

Two new nematode species of the genus Eutobrilus (Nematoda, Triplonchida) from Lake Baikal (Russia)

This paper describes and illustrates two new nematode species of the genus Eutobrilus found in Lake Baikal. Eutobrilus tsalolikhini sp. nov. is most similar to E. mirandus and E. obesus in body size and spicules length. It differs from E. mirandus in its thicker body, longer outer labial setae, larger stoma, and more supplements. It differs from E. obesus in a shorter tail, farther location of vulva from the anterior body end, longer outer labial setae, and more supplements. Eutobrilus olkhonensis sp. nov. is most similar to E. fortis and E. godlewskii in body size and supplements location but differs from both species in a thicker body, longer tail in males, shorter spicules, and fewer supplements.

A new species of Aplectana Railliet & Henry, 1916 (Nematoda: Cosmocercidae) in the Brazilian Amazon and the taxonomic status of Aplectana longa.

Nematodes of the genus Aplectana Railliet & Henry, 1916 are common parasites of the digestive tract of amphibians and reptiles in the Neotropical region. During a parasite survey on Boana boans (Linnaeus, 1758), we found specimens of nematodes with Aplectana characteristics. We observed a set of characteristics that differs the species of our study from its congeners, and the present study describes a new species of Aplectana parasite of B. boans using light microscopy and scanning electron microscopy. Aplectana pella n. sp. has lateral alae and somatic papillae in males and females; males have equal short spicules, and the gubernaculum is absent. The arrangement of pairs of caudal papillae also differs from other species (2 precloacal,1 adcloacal, and 5 postcloacal+1 unpaired). In females, the vulva is simple, with non-prominent lips, and equatorial. This is the first record of the genus Aplectana parasitizing B. boans and the 58th species described for this genus. Additionally, we added the precloacal papillae pattern of A. delirae, and based on morphological and morphometric characteristics, we propose the reallocation of Aplectana longa to the genus Oxyascaris.

Echinocephalus caniculus n. sp. (Nematoda: Gnathostomatidae Railliet, 1895) from the lesser spotted dogfish Scyliorhinus canicula (L.) (Elasmobranchii: Scyliorhinidae Gill, 1862) off Tunisia, with a key to species of the genus Echinocephalus

Echinocephalus caniculusn. sp. (Nematoda, Gnathostomatidae Railliet, 1895) was isolated from the spiral valve of the lesser spotted dogfish Scyliorhinus canicula (L.) from the waters off Kalaat El Andalous, North East Tunisia. This new species is mainly characterized by a cephalic bulb armed with 31–39 transverse rows of uncinated hooks, a comparatively long oesophagus, short spicules and the presence of a gubernaculum. The new species differs from its congeners by having four cervical sacs of almost equal length, a higher oesophagus/body length ratio, the arrangement of the caudal papillae, the absence of a medioventral preanal organ and numerous scattered `pores´ limited to the lateral side of the posterior part of the body. This is the first report of a member of the genus Echinocephalus Molin, 1858 from the Tunisian coast, and a new host and locality record for the Gnathostomatidae. A key to the species of Echinocephalus is provided.

Geomonhystera longisoma sp. nov. и Mongolotheristus tsalolichini sp. nov. (Nematoda, Monhysterida) из устья реки Меконг, Вьетнам

The paper provides illustrated descriptions of two new nematode species of the order Monhysterida Filipjev, 1929 found in the Mekong River Delta in Vietnam. Geomonhystera longisoma sp. nov. is morphologically similar to G. longispiculata Prado-Vera, Ferris, Subbotin, 2018 and G. chiautzingoensis Prado-Vera, Ferris, Subbotin, 2018. However, the new member of the genus has а thicker body, longer outer labial setae, and shorter spicules. Mongolotheristus tsalolichini sp. nov. is similar to M. altaicus Tsalolichin, 1985, but it has amphidial foveas located closer to the anterior body end, shorter dorsal apophysis of the gubernaculum, and papillae-shaped precloacal supplements (absent in M. altaicus). The paper discusses the possibility of maintaining a separate status of the genus Mongolotheristus Tsalolichin, 1985, previously reduced to a synonym of the genus Daptonema Cobb, 1920.

Gammarinema scyllae sp. n. and Monhystrium mangrovi sp. n. (Nematoda: Monhysteridae) from land crabs from New Caledonia

Two new species of nematodes associated with crabs are described from New Caledonia. Gammarinema scyllaesp. n. from the gill chambers of Scylla serrata (Forsskål) is characterised by 3–4 mm long body, small outer labial and cephalic sensilla, distinct ocelli, short straight spicules and sub-cylindrical tail. Monhystrium mangrovisp. n. from the gill chambers and body cavity of mangrove crab Neosarmatium sp. is characterised by 1–1.4 mm long body; outer labial sensilla longer than cephalic sensilla, amphid located at level with posterior stoma chamber, denticles in posterior stoma chamber and five pairs of genital papilla on tail. Phylogenetic relationships of two new species and other nematodes from the family Monhysteridae are analysed based on 18S and partial 28S rDNA sequences.

Morphology, molecular profiles and distribution of Japanese populations of Steinernema tielingense Ma, Chen, Li, Han, Khatri-Chhetri, De Clercq &amp; Moens, 2012 (Rhabditida: Steinernematidae)

Summary Steinernema tielingense was found to be widely distributed in Japan. The molecular characteristics of the nematodes isolated from Japan are basically in accordance with those mentioned in the original description of S. tielingense. However, the Japanese isolates are morphologically distinct from the type population by the following characters: length of the infective juvenile, 711 (671-769) μm, excretory pore of adult males and infective juveniles located posterior mid-pharynx, D% &lt; 50%, smaller H value of 35% and shorter spicules in adult males of both generations. Although discrepancies in morphology and morphometric data between the Chinese isolate and Japanese isolate were observed, the molecular data matched and on this basis the Japanese isolate was identified as being conspecific with S. tielingense. The symbiotic bacterium isolated from the Japanese population of S. tielingense was identified as Xenorhabdus bovienii.

Descriptions of two new and one known species of Parkellus Jairajpuri, Tahseen and Choi, 2001 (Nematoda: Mononchidae) and their phylogenetic position among Mononchida.

Two new species of Parkellus (Jairajpuri et al., 2001) from Vietnam and a population of Parkellus zschokkei (Ahmad and Jairajpuri, 2010; Menzel, 1913) from Ukraine are described, illustrated and their phylogenetic position among the Mononchida is presented. The molecular data (18S and 28S rDNA) are given for the three investigated species – first time for the genus Parkellus. Parkellus hagiangensis sp. nov. is characterized by a medium-sized buccal cavity, posterior position of the dorsal tooth located below the beginning of the pharynx, males having the ventromedian cuticular pores above and below the excretory pore, short spicules with conical proximal part; females with very faint pars refringens vaginae and small teardrop-shaped pieces, short pars distalis vaginae, the presence of small ventromedian vulval papillae. Parkellus tuyenquangensis sp. nov. is characterized by a medium-sized buccal cavity, posterior position of the dorsal tooth located above the beginning of the pharynx, males having the ventromedian cuticular pores above and below the excretory pore, medium-sized spicules with a cylindrical proximal part, very short lateral guiding pieces, females with very strongly sclerotized pars refringens vaginae, medium size teardrop-shaped pieces, short pars distalis vaginae thickened at the junction with pars refringens vaginae. The newly described species are morphologically most similar to P. parkus and P. zschokkei. An identification key to Parkellus species is presented.

Description of a new species Coomansus batxatensis (Mononchida, Mononchidae) from Vietnam, with an updated key to species.

Coomansus batxatensis sp. nov., recorded from Vietnam, is described and illustrated and its phylogenetic relationship within the Mononchida is analysed. The molecular data (18S and 28S ribosomal DNA) are provided for the new species. The new species is characterized by small body size (body length, L = 0.7-0.9 mm); buccal cavity sub-rectangular in shape, flattened at base, 21-24 × 12-13 μm or 1.9 (1.7-2.0) times as long as wide; posterior position of dorsal tooth apex (59-63% from the base of buccal cavity); pars refringens vaginae with faint and small (2.5 × 1.7 μm) teardrop-shaped pieces, short pars distalis vaginae; and males with short spicules (50-51.5 μm) with rounded head and conical blade part. The new species is close to Coomansus parvus but differs from it by the smaller buccal cavity size, more posterior position of the dorsal tooth apex, longer tail and presence of males. An updated identification key to Coomansus species and a compendium of all the species known are presented.