Morphological and molecular taxonomy of a new Daptonema (Nematoda,Xyalidae) with comments on the systematics of some related taxa

A new species of Daptonema is described based upon morphological characters and 18S rRNA sequence. Daptonema matrona sp. nov. was collected in Pina Basin (north‐eastern Brazil). It differs from all other species of the genus by the presence of reduced cephalic setae and straight spicules. These features require an adaptation of the generic diagnosis. Moreover, the females are characterized by intra‐uterine development of the offspring, considered herein as their major autapomorphic feature. Molecular systematic analyses supported Daptonema matrona sp. nov. as a distinct genetic and evolutionary lineage. The data also indicate hypotheses of taxonomic synonymies amongst some related taxa from Xyalidae as well as the paraphyly of Daptonema. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 1–15.     

An integrative approach to characterize cryptic species in the Thoracostoma trachygaster Hope, 1967 complex (Nematoda: Leptosomatidae)

Nematode diversity may seriously be underestimated when taking into account cryptic speciation. Thoracostoma trachygaster is commonly found in kelp holdfasts along the California coastline and was recently shown to consist of at least two distinct molecular clades (I and II). Here, we provide detailed morphological analysis of both clades, based on measurements taken from video vouchers of respectively eight and 16 individuals from the previous study, as well as 80 newly collected specimens from four Californian beaches. The latter were vouchered, measured, and then subjected to molecular analyses of the mitochondrial cytochrome oxidase c subunit I (COI) gene, and the ribosomal D2D3 and internal transcribed spacer (ITS) regions. This integrative approach shows that the three molecular clades are phylogenetically and morphologically distinct species, but a combination of morphological characters is needed to distinguish them. Two new species, Thoracostoma fatimae sp. nov. and Thoracostoma igniferum sp. nov. , are identified and described. The spicule length of T. fatimae sp. nov. is significantly shorter than that of T. trachygaster. Thoracostoma igniferum sp. nov. can be distinguished by the irregular posterior edge of the cephalic capsule and the two internal subdorsal tropis‐like projections in the wall of the cephalic capsule, which are lacking in T. fatimae sp. nov. and T. trachygaster. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 18–35.     

New species of Glochinema and Metaglochinema (Nematoda, Epsilonematidae) from New Caledonia

Glochinema phaleratum sp. n. and Metaglochinema strigosum sp. n. (Glochinematinae, Epsilonematidae) arc described from supralittoral marine sediments in New Caledonia.     

Scientific Report on the Belgian Expedition to the Great Barrier Reef in 1967. Nematodes IX Four new species of Quadricoma Filipjev (Nematoda, Desmoscolecida)

The following species are described: Q. papillata sp.n., characterized by its head-shape with broad truncated anterior end and in males by the possession of 2 single short, stout ventral genital papillae situated anterior to the middle of the body; Q. lizardiensis sp.n., closely related to Q. papillata but distinguished from the latter by its head-shape with a pronounced distally widened anterior border and the absence of genital papillae in the male; Q. freudenhammeri sp.n., characterized by its head-shape with an anteriorly tapering naked front part with thickened, sclerotized cuticle and a rounded posterior part covered with thin cuticle and by the stoma with cheilorhabdia; Q. noffsingerae sp.n., characterized by its head-shape with widened truncated anterior border surrounding 6 sometimes protruding lips, each with a tube-like papilla and by the position of the ocelli situated along the posterior half of the long cylindrical oesophagus.     

Peculiar new deep-sea desmoscolecid species of the genus Protricoma (Nematoda) from Corsica

Three new species of Protricoma were found among the material collected during a deep-sea survey near Corsica: P. Maramphis sp.n., P. mocrocephala sp.n. and P. corsicana sp.n. The new species are characterized by their small body size. a slender cylindrican body with finely annulated body cuticle and a very small head.     

A new genus and species of Epsilonematidae (Nematoda) from New Caledonia

Akanthepsilonema helleouetae gen. et sp.n. (Epsilonematidae) is described from supralittoral marine sediments in New Caledonia. Its main features are a heterogeneous cuticule with large horn-like dorsal spines and a field of copulatory horns in the male. The taxonomic position of the new genus within the family is discussed.     

Marine nematodes from Guadeloupe and other Caribbean Islands. II. Draconematidae

Fourteen species of the nematode family Draconematidae have been found in meiofaunal samples from the Lesser Antilles. Three species, Dracograllus antillensis sp. n., Drucognomus simplex (Gerlach, 1954) and D. Marioni Allen & Noffsinger, 1978 are described or redescribed; information on juvenile stages is included. Faunistic and ecological data are presented for the remaining 11 species.     

Revision of the subfamily Meyliinae De Coninck, 1965 (Nematoda: Desmoscolecoidea) with a discussion of its systematic position

The Meyliinae contains seven species, belonging to four genera: Boucherius Decraemer & Jensen, 1982, Gerlachius Andrassy, 1976, Meylia Gerlach, 1956 and Noffsingtria Decraemer & Jensen, 1982, differentiated from each other primarily by the ornamentation of the body cuticle. The Meyliinae are compared with the Desmoscolecidae ( sensu Lorenzen, 1969; Timm, 1970) and found to be unique in the position and structure of the amphids and in the reflexed branches of the female reproductive system. It is concluded that they belong to the Desmoscolecida, closely related to the Tricominae.     

Deep-sea nematodes (Nemata, Prochaetosomatinae): new taxa from hydrothermal vents and a polymetallic nodule formation of the Pacific (East Rise; North Fiji and Lau Basins; Clarion-Clipperton fracture zone)

Dinetia nycterobia gen. et sp. n. (Draconematidae, Prochaetosomatinae) is described from a hydrothermal site of the East Pacific Rise. The new genus is characterized by body annulation reaching lip region and including spiral amphids, cuticle not thickened in head region, cephalic adhesion tubes without expanded base located in cervical region, pharynx with terminal bulb provided with a thick cuticularized lumen wall, and posterior adhesion tubes with bell-shaped end. Dinetia nycterobia , the type species, is characterized by the number of cephalic adhesion tubes (19 in male, 15 in female) and of the 4 rows of posterior adhesion tubes (5 tubes lateral, 14–19 subventral in male, 10–15 lateral, 13–20 subventral in female) and the shape and size of the spicules. Cephalochaetosoma pacificum notium subsp. n. from the Fiji deep-sea closely resemble C. pacificum pacificum from Philippines deep-sea but differs in male by the number of sublateral posterior adhesion tubes, the shape and size of the spicules, the number of cloacal setae, the structure of the testis and in both sexes by the spiny cuticular ornamentation, the shorter labial setae and morphometric data. A new genus and new species of Draconematidae is provisionally described, based on the observation of juvenile specimens from the polymetallic nodule formation.