Species Of Free-living Marine Nematodes Research Articles

Description of a marine nematode Hopperia sinensis sp. nov. (Comesomatidae) from mangrove forests of Quanzhou, China, with a pictorial key to Hopperia species

A new free-living marine nematode species Hopperia sinensis sp. nov. from mangrove forests of Fujian Province, China, is identified and illustrated. Hopperia sinensis sp. nov. is characterized by its cephalic setae 2.4–2.8 µm long or 17%–20% head diameter, and amphids of 2.25–2.5 turns. Lateral differentiation appears with larger, more irregularly distributed dots behind 3–5 transverse rows of dots posterior to amphid. Buccal cavity is consisted of a shallow and weakly sclerotized cup-shaped portion with strongly sclerotized walls of 18–21 µm deep. There are three sclerotized and size-equally pointed teeth at the junction between the two parts. Spicules of 41–45 µm long are slightly curved with broadband velum and central strips at the proximal end. The gubernacula, with apparent lateral guiding pieces, are formed by one central tubular piece that is weakly sclerotized with 11–16 µm long dorso-caudally directed apophyses. There are 13–14 fine tubular precloacal supplements. Conico-cylindrical tail gradually tapers till pointed tail tip. Female is similar to male, but have a longer body and tail. Ovaries are opposed and outstretched, with anterior ovary to the left and posterior ovary to the right of the intestine. A pictorial key to all the valid known species in genus Hopperia is given.

Three new and two known free-living marine nematode species of the family Ironidae from the East China Sea.

Three new and two known species of free-living marine nematodes of the family Ironidae from the East China Sea are described and illustrated. Conilia sinensis sp. nov. is identified by the relatively large body size (1883-2399 µm); the well developed lips; the number, shape and length of spicule (single and striated, length 87-100 µm as arc); the shape of telamon; the number of supplements (1). Pheronous donghaiensis sp. nov. is characterized by its sharp tail point; caudal gland absent; buccal cavity armed with four big solid teeth and rows of minute denticles; spicules stout, with central septum at proximal end, male caudal region with two rows of small conical subventral papillae. Trissonchulus latispiculum sp. nov. can be distinguished by its head not set off from remaining body, tail short and blunt, buccal cavity with minute denticles, spinneret opening slightly ventrally, spicule broad and alate with central septum and head on proximal end. Trissonchulus benepapillosus (Schulz, 1935) and Trissonchulus oceanus Cobb 1920 which are first reported from China, are redescribed in detail with emphasis on new or hitherto poorly described morphological features. Types are deposited in the Institute of Oceanology, Chinese Academy of Sciences.

New Record of Three Nematode Species of Genus Enoplus (Nematoda: Enoplidae) from Korea

Three unrecorded species of free-living marine nematodes, belonging to genus Enoplus Dujardin, 1845 collected from rocky intertidal seagrass on the eastern coast of Korea, are described and illustrated. Enoplus taipingensis Zhang and Zhou, 2012 is characterized by longer body size, a series of lateral setae throughout the tail in male, the presence of trumpet-shaped precloacal supplement with well-dilated proximal end, and the presence of spicules with five to eight semicircular plates. Enoplus meridionalis Steiner, 1921 is characterized by the presence of trumpetshaped precloacal supplement with slightly dilated proximal end, paired massive spicules, and tail with two pairs of stout terminal setae. Enoplus mammillatus Timm, 1959 is easily distinguished from the congeners by narrow tubular-shaped precloacal supplement. In this study, we provide detailed morphological features of three Enoplus species by differential interference contrast microscopy and scanning electron microscopy. This is the first report on the species of the genus Enoplus from the Korean waters.

An inventory of free-living marine nematodes from Asia’s largest coastal lagoon, Chilika, India

The present study revealed an inventory of free-living marine nematode species from the Asia’s largest coastal lagoon, Chilika (lat. 19°28′ and 19°54′N; long. 085°05′ and 085°38′E), located in the East Coast of India and facing the Bay of Bengal. This study provided a checklist of 64 free-living marine nematode species belonging to 32 genera and 13 families. Among these, marine nematode species Oncholaimus oxyuris has been reported as new distributional record from Indian waters. The distribution of encountered nematode species was investigated in relation with environmental variables such as salinity and sediment texture throughout the lagoon. Most of the nematode species were found in stations which had high salinity (>6) and nature of sediments varied from sandy to silt/clay. However, few nematode families (e.g. Oncholaimidae and Microlaimidae) were also observed in low salinity stations of the lagoon indicating tolerance to variation in salinity.

Description of free-living marine nematodes found in the intestine of fishes from the Brazilian coast.

The marine nematodes usually comprise free-living species, although a few are parasitic. However, several cases of free-living nematodes found accidentally in the digestive tract of certain vertebrates, especially fishes, have sometimes been recorded and categorized as pseudoparasites. In the present work, two species of marine fishes, the rhomboid crappie, Diapterus rhombeus, and the silvered crappie, Eucinostomus argenteus (Perciformes: Gerreidae), from Angra dos Reis on the coast of Rio de Janeiro (Brazil) were examined. Seven species of free-living marine nematodes were found in the digestive tract of these fish. Several of these species remain unknown as free-living forms in Brazil. The combination of the fish feeding strategies and the poor preservation of the body of the nematode specimens found could indicate that these nematodes are pseudoparasites, appearing in the fishes' digestive tracts through accidental ingestion and thereafter surviving for brief periods of time. Descriptions, illustrations and tables of measurements are provided for all species. Six of these species (Croconema torquens, Dorylaimopsis pellucida, Oncholaimellus labiatus, Parodontophora breviamphida, Prooncholaimus ornatus, Trissonchulus latus) have been reported for the first time from the Brazilian coast.

A new species of free-living marine nematode (Nematoda: Chromadoridae) from the East China Sea.

A new species of free-living marine nematodes, Ptycholaimellus longibulbus sp. nov., is described from the East China Sea. Ptycholaimellus longibulbus sp. nov. is characterized by having body length of about 1100-1400 μm, cephalic seta 9 µm long (half a head diameter), a relatively long double posterior pharyngeal bulb occupying 44-49% of pharyngeal length, a voluminous ventral gland with a large ampulla, cuticle with transverse rows of punctations and lateral differentiation with two longitudinal rows of thick dots, relatively long spicules 45-55 μm long, an arcuate gubernaculum 25 µm long, and a conico-cylindrical tail with a distinct long finger-like spinneret. A key to species of Ptycholaimellus is given.

Two new free-living nematode species of Setosabatieria (Comesomatidea) from the East China Sea and the Chukchi Sea

Two new free-living marine nematode species of the genus Setosabatieria from the sandy intertidal zone of Xiamen, in the East China Sea and a shallow water area in the Chukchi Sea, Arctic Ocean are described and illustrated. Setosabatieria longiapophysis sp. nov. is characterized by four longitudinal files with 7–9 cervical setae per file, 15–16 minute papillate precloacal supplements and relatively long straight apophyses of gubernaculum. Setosabatieria major sp. nov. is identified by its relatively large body of 2701–3144 µm, the number (10–11) of cervical setae per file, 26–28 minute papillate precloacal supplements and spicules with a central septum at both the proximal and distal end. A pictorial identification key to all known species of Setosabatieria is provided.http://zoobank.org/urn:lsid:zoobank.org:pub:B8A2BEC9-5CD4-4AA9-9CA8-D1AE1FDE4887

Checklist of free-living marine nematodes from intertidal sites along the central west coast of India

The present study provides a checklist of free-living marine nematode species from nine intertidal sites located along the central west coast of India covering an area between latitudes 16°33′08.47″ N and 16°38′50.75″ N and longitudes 073°19′30.13″ E and 073°23′34.97″ E. The list includes 33 species of marine nematodes belonging to 20 genera and 13 families. The occurrence of nematode species identified appears to be correlated to character of the sediments across sampled intertidal sites. Ten families were encountered in sandy sites while in muddy sites the number was ten. Three families, namely Camacolaimidae, Ironidae, and Microlaimidae, were exclusive to the sandy sites, while Anoplostomatidae, Comesomatidae, and Linhomoeidae were only found across muddy sites. Some of the dominant free-living marine nematode groups encountered across all sites was represented by the genera Ptycholaimellus, Viscosia, Oncholaimus, Halalaimus, and species such as Sphaerolaimus balticus and Metachromadora suecica.

Two new species of Lauratonema (Nematoda: Lauratonematidae) from the intertidal zone of the East China Sea

Two new species of free-living marine nematodes of the genus Lauratonema Gerlach, 1953 from an intertidal sandy beach of the East China Sea are described and illustrated. Lauratonema macrostoma sp. nov. is characterized by a spacious buccal cavity, depth 2.1–2.3 times width; cup-shaped amphids; small blade-like spicules (14–16 µm long, 0.55–0.65 anal or cloacal body diameter [a.b.d.]) and unequal length of outer labial setae and cephalic setae (13–17 µm and 9–12 µm respectively). Lauratonema dongshanense sp. nov. can be distinguished by the small buccal cavity with a strong cuticularized transverse strip structure; cup-shaped amphids; small blade-like spicules (14–15 µm long, 0.58–0.67 a.b.d.), unequal length of outer labial setae and cephalic setae (8–10 µm and 5–7 µm respectively); the presence of a small precloacal papilla. A dichotomous key for the genus Lauratonema is given.http://zoobank.org/urn:lsid:zoobank.org:pub:B5BA6C15-E72A-4C62-97B4-1823E71A9355

Description of Marylynnia puncticaudata n. sp. (Nematoda, Cyatholaimidae) from Bizerte Lagoon, Tunisia

A new free–living marine nematode species of Cyatholaimidae, Marylynnia puncticaudata n. sp. from Bizerte Lagoon (Tunisia) is morphologically described. Males are characterized by a slightly larger body than females, a cephalic ring followed by ten subcephalic setae, modified cuticular punctuation, caudal lateral differentiation of large dots, and strongly cuticularized gubernaculum with a unique shape and bidenticulated distal half. The cuticle ornamentation of females is similar to the males. However, their caudal lateral differentiation is composed of smaller and more spaced dots. An updated morphological key to species of Marylynnia is given.

Three new species of free-living marine nematodes from East China Sea.

Three new species of free-living marine nematodes from intertidal sands in Xiamen, Fujian province are described and illustrated. Bathylaimus denticulatus sp. n. can be distinguished by a relatively small buccal cavity with its second part armed with two distinct teeth, short 2-3 μm labial and 12-16 μm cephalic setae and amphids of 0.8-0.9 turns. Oncholaimus minor sp. n. is characterized by its relatively small body size and the sexual dimorphism in tail shape. Oncholaimus xiamenense sp. n. is identified by pronounced sexual dimorphism in tail shape, the location of postcloacal tubercle (3/4 of the distance from cloaca to tip of tail), the location of female ovary as well as the demanian system (on the right side of the intestine), the number of circumanal genital setae (12). The types are deposited in the Third Institute of Oceanography, SOA, Xiamen.

Two new species of free-living marine nematodes of Adoncholaimus Filipjev, 1918 (Oncholaimida: Oncholaimidae: Adoncholaiminae) from Hokkaido, northern Japan, with a key to species and discussion of the genus

Two new species of free-living marine nematodes,Adoncholaimus daikokuensissp. nov. andA. pseudofervidussp. nov., from the coastal area of northern Japan, are described and illustrated.Adoncholaimus daikokuensissp. nov. is similar to five congeners,A. derjugini,A. punctatus,A. oxyuroides,A. squaluscomb. nov. andA. filicaudacomb. nov. in the absence of a gubernaculum, but differs in the absence of a ventral swelling on tail, spicule length and buccal cavity length.Adoncholaimus pseudofervidussp. nov. is similar toA. fervidusin having large body size, short tail, similar positions of the excretory pore and nerve ring, short spicules, arrangement of subventral setae in posterior region of body in males, and a single pair of terminal pores of the Demanian system surrounded by small gland cells in females.Adoncholaimus pseudofervidussp. nov. differs fromA. fervidusin having smaller, more anteriorly located amphids, longer buccal cavity, absence of gubernaculum in the male, and a different position of the terminal pores in the female. Partial sequences of the mitochondrial cytochromecoxidase subunit I gene (309-337 bp) of the new species are provided for identification based on the DNA barcoding method.Metoncholaimoidesis proposed as a junior synonym ofAdoncholaimus. The new diagnosis ofAdoncholaimusand a key to species are provided.Adoncholaimus squaluscomb. nov.,Adoncholaimus filicaudacomb. nov., andAdmirandus papillatuscomb. nov. are proposed.

A supplement to molecular data for five free-living marine nematode species of the family Comesomatidae Filipjev, 1918 (Nematoda: Chromadorida) from North Vietnam

A supplement to molecular data for five free-living marine nematode species of the family Comesomatidae Filipjev, 1918 (Nematoda: Chromadorida) from North Vietnam

Two new species of the genus Paracyatholaimus Micoletzky (Nematoda: Cyatholaimidae) from the Yellow Sea

Two new free-living marine nematode species of Paracyatholaimus Micoletzky, 1923 Paracyatholaimus qingdaoensis sp. nov. and Paracyatholaimus huanghaiensis sp. nov. from the Yellow Sea, China are described. Paracyatholaimus qingdaoensis sp. nov. is characterized by cylindrical body with conical tail; spicules reverse S-shaped, distally pointed; gubernaculum plate, with two cusps at distal end, parallel to the spicules; 10 thick setose precloacal supplements in a 5 + 5 arrangement, anterior group of five supplements located at a protuberance. Paracyatholaimus huanghaiensis sp. nov. is characterized by a cylindrical body with conic-cylindrical tail; slender spicules curved, distally pointed; gubernaculum handle-shaped, expanding distally to a plate, with some sawteeth at distal end; three papillose precloacal supplements, each papilla protruding conically with cuticularized narrow ducts. A key for identification of species of Paracyatholaimus is proposed.http://www.zoobank.org/urn:lsid:zoobank.org:pub:0A8E40E5-AE7A-47DA-B755-61E1D088C1E9

FREILEBENDE NEMATODEN AUS DEM SUEZKANAL

ABSTRACT Data on the occurrence of 43 species of free-living marine nematodes in the Suez Canal are presented in a tabulated form, and their other distribution is discussed. Particular attention is called to some species (e.g., the Theristus-flevensis group) known as brackish water inhabitants and here regarded as representatives of an old Bitter Lake fauna which existed before the opening of the Canal. In addition, special attention is drawn to four species hitherto reported only from the Red Sea and the Indian Ocean: Theristus aegypticus, Paracyatholaimus duplicates, Enoplus mammillatus, Oncholaimellus pristinus. Redescriptions are given for Paradesmodora campbelli, Gomphionema compacta, Metoncholaimus amplus, Prooncholaimus megastoma.

Four new species of free-living marine nematodes of the family Comesomatidae (Nematoda: Araeolaimida) from coast of Vietnam

Specimens of four new nematode species of the family Comesomatidae were isolated from the sediments of littoral zone of South China Sea at the coast of Vietnam and described and illustrated. Sabatieria curvispiculata sp. n. is characterized by the long and slender tail, short cephalic setae and strongly curved spicules in males. Setosabatiera orientalis sp. n. is close to S. australis Riera, Nunez, Brito, 2006, but differs from it in the comparatively shorter and more slender tail, small-er number of amphidial fovea turns, greater number of precloacal supplements in males and shape and structure of spic-ules. Dorylaimopsis intermedia sp. n. is morphologically closest to D. mediterranea Grimaldi-de Zio, 1968 and D. magellanense Chen, Vincx, 1968, but differs from both species in the longer outer labial setae and absence of precloacal supplements in males. D. brevispiculata sp. n. is similar to D. turneri Zhang, 1992 and D. coomansi Muthumbi, Soetaert, Vincx, 1977, but differs from both species in the shape of outer labial sensillae and absence of precloacal supplements in males. A pictorial key for determination of valid species in the genus Setosabatieria Rouville, 1903 is given.

Marine Nematodes from the Shallow Subtidal Coast of the Adriatic Sea: Species List and Distribution

This study is the first attempt aiming to assess the composition and number of free-living marine nematode species on the coasts of the Marches region, Italy. A high number of putative species of nematodes were recognized (84), these belonging to 52 genera in 22 families. Fifty-one taxa have been identified to the species level increasing the number of known nematode species for the Adriatic Sea from 283 to 310 and for the Mediterranean Sea from 700 to 723. The highest diversity and abundance were registered for the nematode families typically of intertidal zones characterized as medium-fine sands. The majority of the species found in the present study are known to occur in the North European coasts or the North Atlantic Sea, the best known regions for nematode distribution. Inferences on the biogeography of marine nematodes are preliminary since most Biodiversity literature concerning the Mediterranean of the basin is very out of date. Considering the great importance of nematodes in the assessment of ecosystem health conditions, an intensification of sampling efforts should be pursued in other regions in order to improve our current knowledge of the distribution pattern of marine nematode species as well as clarify their biogeographical patterns.

A New Species of Free-living Nematode of Daptonema (Monohysterida: Xyalidae) from the Yellow Sea, China

A new species of free-living marine nematode, Daptonema macrostoma sp. nov. from the Yellow Sea, China is described. The new species is characterized by uniquely large buccal cavity, four cephalic setae, amphid circular, S-shaped spicules with a hook at its distal end, gubernaculum invisible and tail conical-cylindrical.

Two new free-living nematode species (Comesomatidae) from the continental slope of New Zealand, with keys and notes on distribution

Two new free-living marine nematode species of the family Comesomatidae are described from the continental slope of NewZealand, and their distributions at 32 sites are investigated in relation to environmental factors. Vasostoma aurata n. sp. is char-acterised by a distinctly set-off head, amphideal fovea with 4.5 turns, conspicuous chords consisting of two bands fusing atbody extremities, with outline of cell bodies usually golden-coloured, and relatively short spicules. Setosabatieria conicauda n.sp. is characterised by an amphid with 4.25–4.5 turns, the presence of only 1–3 sub-cephalic setae per file, several clusters ofintracellular inclusions, sometimes brown-coloured, in the intestinal wall, and a conical tail. Keys to all known species of Seto-sabatieria and Vasostoma are provided. Both species were mostly restricted to subsurface (1–5cm depth) sediments. The abun-dance of V. aurata n. sp. and S. conicauda n. sp. was significantly correlated with food quantity and quality, but the patternsdiffered between species. The effect of food-related factors may be directly linked to interspecific differences in food require-ments, or mediated by biogeochemical processes (i.e., tolerance of sub-surface oxygen and sulphide concentrations). No signif-icant correlations were found between sediment granulometry and abundances, despite the wide range of sediment grain-sizes (6–93% silt and clay) at the sampling sites.

Checklist of nematodes (Nematoda: Adenophorea) from southeast continental shelf of India

A checklist of free-living marine nematode species recorded from the continental shelf region of southeast coast of India is presented (10°34.03’ to 15°14.48’ N and from 79°52.13’ to 80°53.87’E). The checklist comprise 191 species belonging to 97 genera in 32 families currently know from the area. We provided a synthesis of the taxonomical and ecological work carried out until now that could guide to future research.