Species Of Free-living Marine Nematodes Research Articles

Three Free-Living Marine Nematodes from Sagami Bay, Japan, with a Description of Wiesoncholaimus jambio sp. nov. (Nematoda: Oncholaimidae).

We describe three free-living marine nematode species from Sagami Bay, Japan. Wiesoncholaimus jambiosp. nov. is the second species of this genus. It differs from the type species, Wiesoncholaimus mawsonae Inglis, 1966, by its dorsal tooth, which is as long as the other two teeth; its conico-cylindrical tail, which is as long as 4.6-4.8 cloacal body diameters; and the absence of the gubernaculum. Thalassironus cf. britannicus de Man, 1889 agrees well with a redescription of Thalassironus britannicus de Man, 1889 based on specimens collected near the type locality. However, as it is possible that T. britannicus sensu lato includes two or more species, our species may not be conspecific to T. britannicus sensu stricto. Vasostoma cf. longispicula Huang and Wu, 2010 closely resembles Vasostoma longispicula Huang and Wu, 2010 originally described from China, but minor differentiations are observed in body diameter, body cuticle thickness, and type of precloacal supplements.

Two new species of Enoplolaiminae (Enoplida: Thoracostomopsidae) from Ro Negro and Chubut, Argentina.

Two new species of free-living marine nematodes of the subfamily Enoplolaiminae are described from Ro Negro and Chubut Provinces, Argentina. Enoplolaimus variispiculum sp. n. is characterized by having asymmetric spicules, different in size and distal tips. It is the only species with this characteristic in the whole genus. Mesacanthoides flagellatum sp. n. is characterized by mandibles texture, weakly cuticularized and mottled and mandibular plates with pronounced v shaped incision posterior to the anterior bar. Cephalic capsule wider than long with setae on posterior end, males with long spicules, complex gubernaculum and flagellate tail.

Two new species of nematodes from shallow and deep-water sediments in the South China Sea.

Two new species of free-living marine nematodes from the South China Sea are described: Gomphionema setiforme sp. nov. from intertidal sediment and Paracomesoma longissimum sp. nov. from upper continental slope sediment. Gomphionema setiforme sp. nov. is characterized by the punctated cuticle without lateral differentiation and cuticular pores; short cephalic setiform sensilla; spiral amphideal fovea with 4 turns close to the anterior body extremity; large cuticularized buccal cavity with a massive dorsal tooth; pharynx with a large posterior bulb; short, curved spicules; knife-like gubernaculum without apophyses and 11 cup-shaped precloacal supplements. Paracomesoma longissimum sp. nov. is characterized by cuticle with transverse rows of fine punctuations without lateral differentiation; buccal cavity with three teeth; lateral outer labial setiform sensilla 1.5 times as long as the other four outer labial setiform sensilla; spiral amphideal fovea with 2.5 turns; spicules 350360 m long or 15.716 times cloacal body diameter; plate-like gubernaculum without apophyses and 2528 papilliform precloacal supplements.

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.

Free-living marine nematodes in Andhra Pradesh Coast, India

The present paper reports 43 species of free-living marine nematodes belonging to 32 genera and 10 families from eighteen localities of the Andhra Pradesh Coast. Of these, 22 species are reported for the first time to Andhra waters. A detailed systematic account of the species is presented in this paper.

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.

Four new species of free-living marine nematode from the sea areas of China

Four new species of free-living marine nematode from the sea areas of China

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.

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.

Three new species of free-living marine nematodes (Nematoda: Enoplida) from the Clarion-Clipperton Fracture Zone (CCFZ), North Pacific

Three new species of free-living marine nematodes, Phanodermopsis dordi sp. nov., Halalaimus shinkai sp. nov., and Oxystomina hakureiae sp. nov. are described from the abyssal sediments of the Clarion-Clipperton Fracture Zone, North Pacific. Phanodermopsis dordi sp. nov. differs from the congeners by having papilliform anterior sensilla and a long conical tail with an acute tip. Halalaimus shinkai sp. nov., belonging to Keppner's group 2 based on the presence of caudal alae and the absence of precloacal sensillum or pore, can be distinguished from all of the members of this group by the presence of lateral pieces of gubernacula. Oxystomina hakureiae sp. nov. differs from the congeners by the short setiform anterior sensilla, the amphid located posterior to cephalic sensilla, the conico-cylindrical tail in both sexes, the spicules with a velum and a capitulum, the presence of the gubernacula and the precloacal setae, and the diorchic and monodelphic reproductive systems. The amended dichotomous keys to the species of Phanodermopsis, Halalaimus group 2, and Oxystomina are provided. A new combination Nemanema arenaria (Bussau, 1990) comb. nov. transferred from Oxystomina is also provided.

Two new species of Antomicron Cobb, 1920 (Nematoda: Leptolaimidae) from Jiaozhou Bay, China

ABSTRACT Two new free-living marine nematode species of the genus Antomicron Cobb, 1920 belonging to the family Leptolaimidae are described from the seabed sediment of Jiaozhou Bay of the Yellow Sea. Antomicron holovachovi sp. nov. is characterised by loop-shaped amphideal fovea; male with five straight tubular and 41 alveolar supplements; short cephalic setae; slightly curved slender spicule with cephalated proximal end and tapered distal end; and rectangular gubernaculum with a short dorsal caudal apophysis. Antomicron chinensis sp. nov. is particularly characterised by loop-shaped amphideal fovea; male with only alveolar supplements, without tubular supplement; slender and slightly inverted S-shaped spicule with cephalated proximal end and tapered distal end; and rectangular gubernaculum with a slender dorsal caudal apophysis. An updated identification key to species of the genus Antomicron is also provided. http://www.zoobank.org/urn:lsid:zoobank.org:pub:D7DB980D-4BD5-4966-8756-D7FC2A46DAAA http://www.zoobank.org/urn:lsid:zoobank.org:act:C3142083-6B72-4797-BE50-F8FFC412ACE4 http://www.zoobank.org/urn:lsid:zoobank.org:act:5393CA61-1BE5-4F3B-88AA-501B36472A04

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.

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.

Wieseria bicepes sp. nov. (Nematoda: Oxystominidae) from the South China Sea.

One unrecorded species of free-living marine nematodes from the South China Sea is described as Wieseria bicepes sp. nov. The present species is characterized by three circles of anterior sensilla nearly equal in length; four cephalic setae just behind the outer labial setae; oblong amphideal fovea with double contours and a handle-like protrusion at the base; tail tip bifurcate; spicules slightly curved with proximally cephalated and distally tapered; gubernaculum absent. The species is easily distinguished from the congeneric species by tail with a bifurcate tip and cephalic setae closely adjacent to labial setae.

Two New Marine Free-Living Nematodes from Jeju Island Together with a Review of the Genus Gammanema Cobb 1920 (Nematoda, Chromadorida, Selachinematidae)

In the context of exploration of meiofauna in a sandy intertidal zone of Jeju Island (South Korea), over 70 nematode species are identified, some which have been proven to be new for science. Two new free-living marine nematode species of the family Selachinematidae (Chromadorida, Selachinematidae, Choniolaiminae) are described from the intertidal sandy sediments of Jeju Island (South Korea). Gammanema okhlopkovi sp. n. is closest to Gammanema anthostoma (Okhlopkov, 2002) and differs by having longer cephalic setae (8.5–19 μm in G. okhlopkovi versus 6–7.5 μm in G. anthostoma) and by the presence of precloacal supplementary organs. The genus diagnosis of Gammanema is updated. The genus includes fourteen valid species, while three species are considered species inquirendae due to incomplete diagnoses and illustrations impeding their correct recognition. An annotated list of valid and invalid Gammanema species is provided. A pictorial key for valid Gammanema species is constructed, which consists of two components: (1) simplified images of heads, and (2) a table summarizing most of the significant measured and numeric characters between species. Latronema obscuramphis sp. n. differs from its related species Latronema aberrans (Allgén 1934), Latronema annulatum (Gerlach, 1953), and Latronema spinosum (Andrássy, 1973) by body size, number of supplementary organs, tail shape, length of spicules, and cuticle ornamentation.

A new free-living marine nematode species of Rhinema from the South China Sea

A new free-living marine nematode species of the genus Rhinema belonging to the family Monoposthiidae was collected from marine sediments in the Qiongzhou Strait of the South China Sea, and it is described here as Rhinema longispicula sp. nov. The new species is characterized by coarsely annulated cuticle with 12 longitudinal ridges (alae) marked as reversed V-shaped. The first and second annuli broader and form a kind of a cephalic capsule. The amphideal fovea circular, situated in the middle of the broad second annulus, not surrounded by dense annulations. Buccal cavity cylindrical with a large dorsal tooth. Pharynx with a prominent anterior pharyngeal bulb and an elongated terminal bulb. Elongate spicules strongly curved, with cephalated proximal end and pointed distal end. Gubernaculum boat-shaped, without apophysis. A long and blunt precloacal seta present. Female with two opposed, outstretched ovaries.

Perspiria boucheri sp. nov. (Nematoda, Desmodorida) from the East China Sea

A new free-living marine nematode species from marine sediments in the East China Sea, is described here as Perspiria boucheri sp. nov. The new species is characterized by amphideal fovea surrounded partially by body annulations; four cephalic setae stout; conical buccal cavity with a minute dorsal tooth and two ventrosublateral teeth; pharynx with a pyriform terminal bulb; tail elongated, conical with 3/4 posterior cylindrical portion which having distinct coarse annulations; spicules strongly curved with narrow ventral velum, handle-shaped proximally; gubernaculum canoe-shaped, without apophysis. The new species differs from the most similar species Perspiria striaticaudata (Timm, 1962) by strongly curved spicules with handle-shaped proximal end, gubernaculum without dorsal apophysis and relatively shorter tail. Updated key to all species of Perspiria is provided.

A new species of PomponemaCobb, 1917(Nematoda: Cyatholaimidae) from Northeast of Brazil, with reference to the taxonomic status of the genera ParapomponemaOtt, 1972 and PropomponemaOtt, 1972.

A new species of free-living marine nematode is described from Itapuã beach, northeast of Brazil. Pomponema veronicae sp. n. differs from other species of Pomponema by having buccal cavity with large pointed dorsal tooth, two subventral teeth and pairs of denticles, gubernaculum with two L-shaped lateral plates and having a membrane at its distal end that connects to L-shaped plate, and presence of a ventral orifice at distal end of L-shaped plates. It also differs from other species in the size of spicules and gubernaculum. The new species is considered most closely related to Parapomponema species because of the L-shaped lateral plates of gubernaculum, but the taxonomic status of Parapomponema was reviewed and Parapomponema and Propomponema are now synonymized with Pomponema. Pomponema cyatholaimoides is considered as a species inquirendum and Pomponema carinatum is accepted as Pomponema loticum. An updated identification key to species of Pomponema is included.

A new species of Pomponema Cobb, 1917 (Nematoda: Cyatholaimidae) from Northeast of Brazil, with reference to the taxonomic status of the genera Parapomponema Ott, 1972 and Propomponema Ott, 1972

A new species of free-living marine nematode is described from Itapuã beach, northeast of Brazil. Pomponema veronicae sp. n. differs from other species of Pomponema by having buccal cavity with large pointed dorsal tooth, two subventral teeth and pairs of denticles, gubernaculum with two L-shaped lateral plates and having a membrane at its distal end that connects to L-shaped plate, and presence of a ventral orifice at distal end of L-shaped plates. It also differs from other species in the size of spicules and gubernaculum. The new species is considered most closely related to Parapomponema species because of the L-shaped lateral plates of gubernaculum, but the taxonomic status of Parapomponema was reviewed and Parapomponema and Propomponema are now synonymized with Pomponema. Pomponema cyatholaimoides is considered as a species inquirendum and Pomponema carinatum is accepted as Pomponema loticum. An updated identification key to species of Pomponema is included.

Three new species of the free-living marine nematode Metoncholaimus Filipjev, 1918 (Enoplida, Oncholaimidae) from Argentinean coasts.

Three new species of free-living marine nematodes of the genus Metoncholaimus are described from San Matías gulf (Río Negro, Argentina). Metoncholaimus sanmatiensis sp. n. is characterized by large body size, long spicules, small gubernaculum, presence of long setose pre- and postcloacal genital sensilla and presence of precloacal pores. Metoncholaimus perdisus sp. n. is characterized by small-sized body, short spicules, small gubernaculum, presence of long setose pre- and postcloacal genital sensilla and presence of pre- and postcloacal pores. Metoncholaimus paracavatus sp. n. is closely related to Oncholaimus cavatus but can be considered as a new Metoncholaimus species based on the presence of gubernaculum and the morphology of the demanian system. A compendium of all valid species, including new species, is given.