Precloacal Supplements Research Articles

One new species of free-living marine nematode from the Yellow Sea, China

A new species of Setostephanolaimus Tchesunov, 1994, S. longiseta sp. nov. was discovered in an intertidal sand beach along the Rizhao coast of the Yellow Sea. It is characterized by its long and slender body, long cephalic setae (longer than 20 m and 16 m in males and females, respectively) and subcephalic setae, long spicules (longer than 90 m), gubernaculum with dorsal hooked apophyses, along with presence of 1012 tubular precloacal supplements in males. Updated dichotomous key for species of the genus Setostephanolaimus is also given.

Eutobrilus godlewskii sp. nov. and Tobrilus gigas sp. nov. (Nematoda: Triplonchida) from Lake Baikal, Russia

Eutobrilus godlewskiisp. nov. and Tobrilus gigassp. nov. are described and illustrated based on the material collected from Lake Baikal, Siberia, Russia. The species Eutobrilus godlewskiisp. nov. morphologically is close to E. fortis (Tsalolikhin, 1972) and E. prodigiosusShoshin, 1988. From the former species it differs in the narrower labial region, longer outer labial setae, longer spicules and the absence of crystalloids. It differs from E. prodigiosus in the comparatively longer pharynx, another structure of stoma, longer spicules, another arrangement of precloacal supplements and the absence of crystalloids. Another new species, Tobrilus gigassp. nov. is the largest among valid species of the genus Tobrilus. Morphologically it is close to T. undophylusShoshin, 1988 and T. kamtschaticusGagarin, 2004. From the former species it differs by having a narrowed male body, longer outer labial setae and spicules. From T. kamtschaticus it differs in wider labial region, longer outer labial setae and spicules. This article presents two tables showing the morphological characteristics of males among valid species of the genus Eutobrilus and Tobrilus from Lake Baikal.

Molecular characterization of free-living nematodes from Kermadec Trench (Nematoda: Aegialoalaimidae, Xyalidae) with description of emAegialoalaimus/em emtereticauda/em n. sp.

The Kermadec Trench is the world's fifth deepest trench and extends from approximately 26 to 36°S near the northeastern tip of New Zealand's North Island. Here, we describe a new species of Aegialoalaimus, a nematode genus with unusual buccal cavity and pharynx morphology, from a site at 9540 metres water depth in Kermadec Trench, and provide the first SSU and D2-D3 of LSU sequences for Aegialoalaimus, Manganonema, Metasphaerolaimus constrictus and Daptonema amphorum. Aegialoalaimus tereticauda n. sp. is characterised by body length 755-864 µm, cephalic sensilla papilliform ( 1 µm long), excretory pore located slightly anterior to posterior bulb in males and slightly anterior to nerve ring in females, arcuate spicules 18-22 µm long, gubernaculum present, precloacal supplements absent, and cylindrical tail 58-64 µm long with rounded tip. Relationships between Aegialoalaimus and Chromadorean orders could not be elucidated based on our SSU analysis; no link could be found with the Plectida, where the Aegialoalaimidae is currently placed, or with the Isolamiida or Cylindrolaimus (Areaolaimida), which share a similar and unusual buccal and pharynx morphology. Our SSU phylogenetic analysis confirms the placement of Manganonema within the Xyalidae, although relationships with other xyalid genera remain unclear. The Sphaerolaimidae formed a clade together with the Monhysteridae, which contradicts the current classification where the Sphaerolaimidae and Xyalidae are classified together into the superfamily Sphaerolaimoidea and the Monhysteridae into the Monhysteroidea. Although limited research has been conducted on the nematode diversity in Kermadec Trench to date, the available data show that half of all invertebrate species known from the trench are nematodes, which highlights the importance of conducting further taxonomic research on this group in hadal environments.

Further data on Iranian marine nematode diversity, with description of three new Desmodoridae Filipjev, 1922 (Nematoda: Desmodorida) species from the Persian Gulf

Summary The Desmodoridae is a diverse and widespread family of free-living nematodes. Here, we provide the first record of the group in the Persian Gulf and describe three new species: Metachromadoroides sinuspersici sp. n., Zalonema iranicum sp. n. and Z. supplementorum sp. n. Metachromadoroides sinuspersici sp. n. is characterised by finely annulated cuticle, short and stout cephalic sensilla, amphidial fovea on cuticular thickening, pharyngeal bulb well developed and partitioned into three sections, absence of precloacal supplements, and presence of 6-8 pairs of rounded postcloacal papillae. Zalonema iranicum sp. n. is characterised by papilliform subcephalic sensilla (best observed with SEM), convex cephalic capsule, large multispiral amphidial fovea with 4-5 turns in both males and females, buccal cavity with one ventrosublateral and two dorsal teeth and posterior body of males with lateral alae extending from the last third of the body to the cloacal aperture and ventral alae extending 1395-2250 μm anterior to the cloacal aperture, and no precloacal supplements. Zalonema supplementorum sp. n. is characterised by four subcephalic sensilla 1-2 μm long, multispiral amphidial fovea with three turns in both males and females, buccal cavity with one dorsal and two ventrosublateral teeth, males with lateral alae present on each side of body from posterior half of body to cloacal aperture, ventral alae extending 942-1257 μm anterior to cloacal aperture, strongly cuticularised spicules 41-43 μm long, and 12-16 precloacal supplements. Near full length SSU and partial D2-D3 LSU sequences are provided for M. sinuspersici sp. n. and Z. iranicum sp. n., and the COI sequence is provided for Z. iranicum. The SSU phylogeny suggests a close relationship between M. sinuspersici sp. n. and Metachromadora and Metachromadoroides species and the monophyly of Zalonema (after currently available data). The LSU phylogeny suggests an affinity between Metachromadoroides and Zalonema with Spirinia and Acanthopharynx, respectively.

Descriptions of Deontolaimus holovachovi sp. nov. and Campylaimus zhoui sp. nov. from Chinese sea areas

AbstractTwo new species of free-living marine nematode discovered from an intertidal sandy beach in the Bohai Sea and from a sublittoral region in the East China Sea are described. Deontolaimus holovachovi sp. nov. is characterized by short cephalic setae (2.5–3 μm long); ventrally-unispiral amphidial fovea; excretory pore located at the level with nerve ring; lateral alae present; two pairs of lateral cervical setae present; arcuate spicules 1.5–1.6 cloacal body diameter long, with the proximal half swollen and proximal end hooked, the distal half narrow; gubernaculum with dorso-caudal apophysis; postcloacal sensilla present in males; a midventral caudal papilla with a short seta situated at posterior third of tail length. Campylaimus zhoui sp. nov. is characterized by loop-shaped amphid with very long ventral limb extending along pharyngeal region to level of anterior part of intestine, 4.7–5.2 times the length of dorsal limb; excretory pore opening posterior to the pharyngo-intestinal junction; spicules symmetrical, slightly arcuate without proximal capitulum; gubernaculum with small dorsal apophysis; precloacal supplements absent.

A new free-living marine nematode species of the genus <i>Belbolla</i> (Enoplida, Enchelidiidae) from a subtidal zone of the East Sea, Korea, with some ecological and biogeographical information

A new free-living marine nematode species of the genus Belbolla Andrassy, 1973 belonging to the family Enchelidiidae is described based on specimens collected from the sediment of a subtidal benthic environmental habitat in the East Sea, Korea. Belbolla wonkimi sp. nov. differs from its congeners by the combination of the following characteristics: a relatively long body (3263-3396 μm), the absence of ocelli, nine oesophageal bulbs in the posterior pharynx, well-developed two winged precloacal supplements, longer spicule length (115-130 μm, 1.6-1.8 anal body diameter long), and a triangle-shaped shorter gubernacular apophysis (17-18 μm). Comparative tables on the biogeographical and morphological characteristics of Belbolla species are presented. A DIC (differential interference contrast) photomicrograph of the new species is also provided. This is the first taxonomic report on the genus Belbolla from Korean waters.

Description of a new marine predatory nematode Latronema dyngi sp. nov. (Nematoda, Chromadorida, Selachinematidae) from the west coast of Sweden and an updated phylogeny of Chromadoria

A new nematode species, Latronema dyngi sp. nov., is described from Skagerrak off the west coast of Sweden with the type locality near Dyngö island. Latronema dyngi sp. nov. is characterized by multispiral amphideal fovea with circular outline, 0.2–0.3 corresponding body diameters wide in males and 0.1–0.2 corresponding body diameters wide in females, 12 cuticular longitudinal ridges and 18–27 precloacal supplements in males. Latronema dyngi sp. nov. most closely resembles L. orcinum in terms of body length; demanian ratios a, b, c and c′; number of amphid turns in males; and the ratio of spicule length to cloacal body diameter. The two species can be differentiated by the number longitudinal ridges on the cuticle (12 for Latronema dyngi sp. nov. vs 20–22 for L. orcinum) and spicule length (65–78 μm for L. dyngi vs 60 for L. orcinum) and shape (weakly arcuate for L. dyngi sp. nov. vs strongly arcuate for L. orcinum). We also performed a maximum likelihood phylogenetic analysis on over 250 nematodes of the subclass Chromadoria based on their nearly full-length 18S rDNA sequences. In agreement with previous studies, our analysis supported Selachinematidae as a monophyletic group and placed Richtersia Steiner, 1916 within Desmodoridae Filipjev, 1922 or just outside of the main Desmodorida clade with the latter placement not well supported.

Two new nematode species of the genus Paratrilobus Micoletzky, 1922 (Nematoda, Triplonchida) from the water area of Lake Baikal (Russia)

This paper describes and illustrates two new nematode species of the genus Paratrilobus Micoletzky, 1922. The species Paratrilobus tankhoyensis sp. nov. was found at the estuary of the Pereyomnaya River (water area of Lake Baikal, near the Tankhoy railway station). Paratrilobus tankhoyensis sp. nov. is most similar to P. expugnator (Tsalolichin, 1976) in the body size, but differs in the comparatively thin body, shorter and thicker tail, shorter stoma and spicules. Another new species, Paratrilobus aquaticus sp. nov., was found in Posolsk Bank (natural underwater elevation of the bottom between the southern and central basins of Lake Baikal). The species is similar to P. granulosus Gagarin & Naumova, 2011 and P. ultimus (Tsalolichin, 1977) in the structure of the precloacal supplements. It differs from the former in the absence of crystalloids, a comparatively longer pharynx, longer stoma and outer labial setae as well as the absence of subterminal seta. It differs from the latter in a longer pharynx, stoma and longer outer labial setae as well as a longer and more slender tail. We also discuss diagnostic features of the males of the genus Paratrilobus.

Paragnomoxyala papillifera sp. nov. (Nematoda: Monhysterida) from the Bohai Sea, China

A new free-living marine nematode species of the family Xyalidae from Laizhou Bay of the Bohai Sea, China is described and illustrated herein. Paragnomoxyala papillifera sp. nov. is characterized by large funnel-shaped buccal cavity, circular amphidial fovea located posterior to buccal cavity, straight spicules with slightly curved distal end, gubernaculum absent, four papilliform precloacal supplements, tail conico-cylindrical with two ventral embossments in males and having longitudinal rows of cervical setae and subventral caudal setae in males. The new species is easily identified from other two recorded species in the genus by having papilliform precloacal supplements and ventral embossments along conical portion of tail of males. A pictorial key for three species of Paragnomoxyala and comparative table of three species with important characteristics are provided.

Two new nematode species (Plectida: Leptolaimidae, Rhadinematidae) from Chatham Rise, New Zealand.

Two new species of the order Plectida are described from Chatham Rise, New Zealand. Leptolaimus dififtinus sp. nov. is characterised by the short body 319–420 microns long, truncate labial region slightly offset from body contour and bearing conspicuous outer labial papillae, cephalic setae 1.3–1.4 microns long, amphid located 4–9 microns from anterior end, lateral alae originating from middle of buccal cavity length, female without supplements, male with precloacal and postcloacal pairs of subventral setae, nine tubular supplements (alveolar supplements absent), tubular supplements weakly S-shaped with pointed tip, spicules arcuate 24 microns or 1.4 cloacal body diameters long and dorsal gubernacular apophyses. Lavareda iramscotti sp. nov. is characterised by adult body length 3,023–3,121 microns long, eight longitudinal rows of body pores each with short papilla, cephalic setae 4–5 microns long, tail 146–165 microns long, male with spicules 54 microns long, gubernaculum with triangular apophyses, 20 precloacal supplements with bifid distal tips arranged in 9 + 1 + 10 pattern, female with vulva at 55% of body length from anterior and cuticularisation perpendicular to vagina at level of vulva. The present study provides the first record of a Leptolaimus species from the New Zealand region and the first description of a female specimen of the genus Lavareda.

Molecular and morphological characterisation of Trichodorus species (Nematoda: Trichodoridae), with description of T. pseudoaequalis n. sp. from California and other states of the USA

Summary During surveys for stubby root nematodes in the natural vegetation of California, Oregon and Washington, USA, three known species, viz., Trichodorus californicus, T. intermedius and T. obscurus were recovered together with ten unidentified Trichodorus species. The three known and one new species were studied using an integrated approach. Trichodorus pseudoaequalis n. sp. is characterised by a medium-sized body about 800 μm long on average, male with two ventromedian cervical papillae anterior to secretory-excretory pore and three precloacal supplements all located anterior to the retracted spicules; spicules 39 μm long (average), slightly ventrally curved, more so in head region and blade with slight indentation mid-way and striation more pronounced in posterior half. Females possess a rather short (average 33% of corresponding body diam.) pear-shaped vagina with small vaginal sclerotised pieces (ca 1.5 μm long), rounded triangular in shape, obliquely orientated and close together; one pair of sublateral body pores anterior (about four vulval body diam.) to vulva and one pair of post-advulvar sublateral body pores. Trichodorus pseudoaequalis n. sp. differs from the most similar species, T. aequalis, in male characters like general spicule shape and ornamentation and in the position of the dorsal pharyngeal gland nucleus in both sexes (at same level of posterior ventrosublateral pair vs clearly separated). The phylogenetic relationships of the recovered species were reconstructed using the ITS2 rRNA and the D2-D3 expansion segments of 28S rRNA gene sequences.

Phylogenetic relationships of Leptolaimus de Man, 1876 (Plectida: Leptolaimidae) with description of two new species from the Persian Gulf, Iran

Summary Members of the family Leptolaimidae are reported for the first time from Iran with description of two new species of Leptolaimus from the Persian Gulf in the south of the country. Leptolaimus hormozganensis sp. n. is described based upon three populations. It differs from other Leptolaimus species in the position of the pharyngeal supplement and the number of precloacal tubular supplements and has a single sickle-shaped tubular pharyngeal supplement at mid-pharynx level in both sexes, 9-12 male precloacal supplements and one female preanal supplement. Leptolaimus dimorphus sp. n. is characterised by the presence of a pharyngeal tubular supplement only in some adults, one female preanal supplement and four male precloacal supplements. It differs from other species in that the pharyngeal supplement is only present in some specimens, presence of four male precloacal supplements, tail 50-59 μm long and ventrosublateral position of vulva on either the right or left side of the body. Near full length SSU rDNA sequences are provided for L. hormozganensis sp. n. and two different males (one with, and one without, a pharyngeal supplement) of L. dimorphus sp. n. COI sequences for three populations of L. hormozganensis sp. n. from different regions of the Persian Gulf are also obtained. New sequences of two Leptolaimus species formed a clade with other sequenced Leptolaimus spp. and representatives of two genera of Leptolaimidae, i.e., Aphanolaimus and Paraplectonema in a phylogeny based on SSU rDNA gene with 1.00/81 Bayesian posterior probability/maximum likelihood bootstrap (BPP/BS) values. Molecular phylogeny confirmed the synonymy of Leptolaimus and Halaphanolaimus that was formerly proposed based only on morphology. Based on SSU sequences and morphological characters, the presence of a pharyngeal supplement may not be a species-specific character and should not be used to differentiate genera.

One new species and one new record species of Sphaerolaimus (Nematode, Sphaerolaimidae) in offshore wetlands, China

One new species and one new record species of Sphaerolaimus are described. Sphaerolaimus longispiculatus sp. nov. is characterized by body length 2 213–2 470 µm, amphideal fovea 12%–16% corresponding body diameters in males and 9%–10% corresponding body diameters in females, long slender spicules 2.8–3.8 cloacal body diameters, eight small papilliform precloacal supplements, gubernaculum without apophysis, and tail conico-cylindrical, 2.5–3.7 cloacal/anal body diameters long. Sphaerolaimus gracilis is recorded from the first time in the mangroves wetlands, it can be distinguished from the original desceiption by longer spicules (66–71 µm vs 56 µm) and wider body (a=20.1–21.4 vs 25).

Description of Two New Species of Free-Living Nematodes (Nematoda) from Vietnam

An illustrated description of two free-living nematode species—Leptolaimoides brevicaudatus sp. n. and Paramonhystera affinis sp. n.—from the water bodies of Vietnam is presented. L. brevicaudatus is similar to L. thermastris (Lorenzen, 1966); L. gangioensis Hoang Lai-Phu et al., 2009; and L. asiaticus Gagarin, Nguyen Vu Thanh, 2005 in regards to body size, but differs from these species by a shorter and less slender body, longer spicules, and the absence of precloacal supplements in males. Paramonhystera affinis sp. n. is morphologically similar to P. parabutschlii (Timm, 1961) and P. levicula (Lorenzen, 1972), but it has shorter and sparse somatic setae, six outer labial setae (versus four outer labial setae in both compared species), and shorter spicules.

A new nematode species, Chromadorina tangaroa sp. nov. (Chromadorida: Chromadoridae) from the hull of a research vessel, New Zealand.

Chromadorina is a globally distributed, largely marine nematode genus frequently found on a variety of organisms, including macro- and microalgae and crustaceans, as well as artificial substrates such as settlement plates and ship hulls. Here, Chromadorina tangaroa sp. nov. is described from filamentous seaweed growing on the hull of RV Tangaroa anchored in Wellington, North Island of New Zealand. It is characterized by body length 763–1,086 μm, and pore of secretory-excretory system located at or near level of teeth. Males have spicules with rounded capitulum followed by a narrower shaft and blade tapered distally, a gubernaculum as long as the spicules, and three cup-shaped precloacal supplements, and females are characterized by a cuticularized prevulvar pad, vagina located at 46–48% of body length from anterior, and vagina anteriorly directed. Chromadorina tangaroa sp. nov. is the first species of the genus to be described from New Zealand, but it is unclear whether it is native to the region because it may have dispersed as part of ship hull biofouling communities. Long-distance transport of nematodes through ship hull biofouling may be a common occurrence, but too little is known about the occurrence of nematodes on ship hulls to gauge the potential effect of shipping on nematode species distributions.

A new species of Microlaimus de Man 1880 (Nematoda: Microlaimidae) from the Black Sea.

Microlaimus sergeevae sp. n. is described and illustrated from the Crimea shelf of the Black Sea. It is characterized by the 1301-1728 μm long body; cuticle with distinct annuli; spicules 34-37 μm long, curved; gubernacular apophyses 20-25 μm long, surrounding distal end of spicules; criptocyrcular amphidial fovea 7-8 μm in diameter; cervical setae present; four submedian rows of pores spreading along the whole body length, and eight precloacal supplements in males. The new species morphologically resembles M.gerlachi Wieser 1954, M. paraborealis Allgen 1940a and M.kaurii Wieser 1954, but differs from them by the length of cephalic setae, size of the body, presence of cervical setae, shape of the gubernacular apophyses, eight tubular precloacal supplements and submedian rows of pores spreading along the whole body length. M.sergeevae sp. n. differs from M.gerlachi by having a smaller amphidial fovea, shorter spicules and gubernacular apophyses. The new species differs from M. paraborealis by having larger value of c. It differs from M. kaurii by having longer spicules and larger values of c and b.

Description of Pseudosteineria longisetis sp. n. from northeastern Brazil with a review of the genus Pseudosteineria Wieser, 1956 (Nematoda: Xyalidae).

A new free-living marine nematode of the family Xyalidae is described from Armação Beach, northeastern Brazil, and the genus Pseudosteineria is reviewed. Pseudosteineria longisetis sp. n. is characterized by having six groups of long subcephalic setae, amphids situated slightly anterior to the groups of subcephalic setae or at the level of the first subcephalic setae, long somatic setae located posteriorly to subcephalic setae and distributed along the body, one papiliform precloacal supplement, and gubernaculum with dorso-caudal apophysis. An emended diagnosis of the genus, an updated list of species and dichotomous identification key, and a pictorial key are given. A comparative table including the main characters of all Pseudosteineria species is also provided.

Leptolaimus holovachovi sp. nov. (Nematoda) from Shenzhen Mangrove Nature Reserve, Shenzhen, South China

A new free-living marine nematode species of the genus Leptolaimus belonging to the family Laptolaimidae was collected from intertidal sediments of the Shenzhen Mangrove Nature Reserve, Shenzhen, South China, and it is described here as Leptolaimus holovachovi sp. nov. The new species is characterized by body length 734–896 µm in males and 822–941 µm in females; papilliform cephalic sensilla; circular amphideal fovea; males with 7–14 anterior midventral alveoli in the pharyngeal region, 4–5 midventral tubular precloacal supplements and 4–6 alveolar precloacal supplements; spicules slender, slightly arcuate, proximally cephalated and distally pointed. Plate-like gubernaculum without apophyses. The new species differs from other congener species of the genus by the unique feature of having anterior midventral alveoli in the pharyngeal region.

A new species of Cephalanticoma (Enoplida: Anticomidae) from Brazilian coast (Atlantic Ocean), with emended diagnosis and dichotomous key to the genus.

A new species of the genus Cephalanticoma is described for the Atlantic Ocean in the Potiguar Basin off the continental shelf of northeast Brazil. Cephalanticoma rugatusa sp. n. is characterized by bearing head capsule ending on the level of amphideal fovea, a tubular precloacal supplement and two rows of thin precloacal setae. Cephalanticoma rugatusa sp. n. differs from all other species of the genus by having a precloacal cuticular papilla in front of the cloaca and a cuticular transversal wrinkle which extends from the papilla elevation to the conical-cylindrical portion of the tail occupying both subventral regions. An emended diagnosis and a dichotomous key to species based on both genders are provided.

Two New Species of Free-Living Marine Nematodes of the Desmodoridae from Mangrove Wetlands of Xiamen Bay, China

Mangroves are unique in their biodiversity, but studies on their meiobenthic biodiversity in China are scarce. Despite the importance of mangroves, little work has been done on the classification of nematodes in mangrove wetlands. Fujian Province is the most northern point of China’s natural mangrove distribution, and it is also one of the provinces with the earliest constructed mangrove forest. In this paper, two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described. Metachromadora xiamenensis sp. nov. is characterized by a cylindrical body, and smooth head capsule set off from the rest of the body. The cuticle is finely annulated and thickened at the midbody. Lateral ridges run from the posterior end of the pharynx to the middle of the tail. The amphid foveae is loop shaped and opens at the top with a double contour amphidial, pharynx with bipartite cuticularized internal cavity. There are 18 tubular precloacal supplements and tail with three small protuberances. Molgolaimus euryformis sp. nov. is characterized by a relatively short and plump body with finely annulated cuticle, which is particularly obvious in the tail. The head is small and wide with intensive striates. The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis, a gubernaculum with a block-shaped hook, a swollen conical-cylindrical tail and an absence of precloacal supplements.