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Summary The fine morphology of the buccal capsule and intestine (midgut) of the marine free-living nematode Odontophora deconincki was investigated. The cheilostome is armed with six equal claw-like odontia that can evert radially by opening the mouth. Light-refracting accessory buccal structures within the cheilostomatal cuticle alternate with odontia and consist of two elements: anterior armilloids and posterior granular armilliths. The buccal cavity (pharyngostome) is surrounded by a complex of longitudinal and oblique muscles partially attached to the cheilostome cuticle at the sites of the accessory buccal structures and enabling a wide opening of the mouth. With the described stoma condition, the nematode probably scrapes food particles from the substrate surface. In cross-section, the midgut consists of 5-7 cells that appear uniform throughout its length. An extracellular matrix (glycocalyx) over the microvillar brush varies in thickness and stratification depending on presence or absence of food content in the lumen. Abundant spherocrystals (globular inclusions with concentric striations) were present in all gut cells. No indication of endocytosis or digestive vacuoles was observed in the gut cells and extracellular digestion predominates. Most specimens had a gut content formed from a long cylinder of compressed flocculent material with some barely identifiable components and few spherocrystals expelled from the enterocytes. We assume that the nematode diet comprises a wide range of objects, mainly eukariotic epigrowth organisms, which are shorn off and scraped from the surface of sand grains and then ingested.

Illustrated descriptions of two new nematode species found in artificial reservoirs for shrimp cultivation are given: Pseudolella tenuis sp. n. and Paracomesomaleptum sp. n. The former is morphologically close to P. bengalensis (Timm 1957) and P. capera Tchesunov 1978, but differs from P. bengalensis by a shorter body, comparatively longer pharynx, shorter and less slender tail, longer stoma, shorter ventral branch of the amphideal fovea, and shorter spicules and cephalic setae. It differs from P. capera by shorter cephalic setae, wider labial region, longer ventral branch of the amphideal fovea, and longer spicules. Paracomesomaleptum sp. n. is morphologically close to P. susannae Semprucci 2015 and P. minor Gagarin et Nguyen Dinh Tu 2014. From the former species it differs by its shorter and thicker body, shorter cephalic and subcephalic setae, and less numerous precloacal supplements in the male. This new species differs from P. minor by a less slender tail, shorter cephalic and outer labial setae, the presence of subcephalic setae, and longer spicules.

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.

The diversity of free-living aquatic nematodes is largely unknown for the Gulf of Mexico and Caribbean Sea. The Cuban Archipelago is an important part of this because of its large area and diversity of habitats. We analyzed the free-living nematodes from 83 sites from seven aquatic habitats around Cuba, to produce a checklist for many habitats, including seagrass meadows, coral degradation zones, algal turf, bare sands, unvegetated muds, freshwater and anchihaline caves, and deep-sea sediments. The checklist contains 469 species, 229 genera, 50 families, and 9 orders. Chromadorida, Enoplida, and Monhysterida were the best represented orders with 112, 100, and 83 species respectively. The most abundant species were Euchromadora vulgaris, Terschellingia longicaudata, Desmodora pontica, Sabatieria pulchra , and Epsilonema sp. Most of the listed species were new records for the region. There were differences in the number of species recorded in each habitat type, with seagrass meadows having 280 species, coral degradation zones having 139 species, deep waters having 116 species, algal turf having 114 species, bare sands having 100 species, unvegetated muds having 78 species, freshwater caves having 19 species, anchihaline caves having 16 species, and freshwater streams having 6 species. The checklist is the most comprehensive recent report of the diversity of free-living nematodes in the regions of Gulf of Mexico and Caribbean Sea. The reported diversity is higher than many other regional checklists likely reflecting the intense sampling effort and the variety of microhabitats in Cuban Archipelago.

The new genus and species Campydoroides manautei Holovachov gen. et sp. nov. is placed in the suborder Campydorina and is characterised by a transversely striated cuticle without lateral alae, body pores or epidermal glands; somatic sensilla only on pharyngeal region and on tail; a truncate labial region with papilliform inner labial, outer labial and cephalic sensilla; a stirrup-shaped amphid with transverse slit-like opening; a conoid stoma with strongly cuticularised walls and large protrusible dorsal tooth; a cylindrical pharynx with distinct basal bulb but without valves; a large ovoid cardia; didelphic, amphidelphic female gonads with antidromously reflexed ovaries and without spermatheca; a transverse vulva; a straight vagina without pars refringens vaginae or epiptygmata; an elongate tail with caudal glands and spinneret. The new genus is similar to the genera Campydora Cobb, 1920 and Udonchus Cobb, 1913 in having papilliform labial and cephalic sensilla, a stirrup-shaped amphid with a transverse slit-like opening, a stoma with a well-developed protrusible dorsal tooth, and a muscular pharynx with a strongly developed basal bulb, but can be easily separated from both in details of a stoma morphology. The systematics of the suborder Campydorina is revised. Halirhabdolaimus Siddiqi, 2012 is synonymised with Syringolaimus de Man, 1888.

Aphanolaimus strilliae n. sp. and Makatinus africanus n. sp. are described from freshwater sources in the Telperion Nature Reserve, Mpumalanga, South Africa. Aphanolaimus strilliae n. sp. is characterised by a body length of 1240–1613 μm, more than 800 body annules, lateral field originating between the first and second lateral body pore at the 34th–46th annule, first lateral body pore located at the 25th–35th annule, vagina V-shaped and bent anteriorly, 142–195 µm long uterus and 165–207 µm long tail with spinneret offset. This species is ovoviviparous and no males were found. Makatinus africanus n. sp. is characterised by a large, thick body (3228–4128 μm long, a = 30–39 wide), slightly set off lip region with amalgamated lips; 31–34 μm long odontostyle; long tongue-shaped cardia, and stout, short tail (30–43 μm long) with a small peg / digitate extension and male absent. Populations of three known species, Chronogaster africana, Eutobrilus annetteae and Neotobrilus ampiei, from fresh water at the Telperion Nature Reserve are described and scanning electron microscope graphs of these species published for the first time.

The new genus Neodiplopeltula gen. nov. is proposed to accommodate those species from the genus Diplopeltula Gerlach, 1950 that possess the following morphological characters: amphids in the shape of an elongated loop, a well-developed subcylindrical stoma and outstretched ovaries. The genus Diplopeltula is considered genus inquirendum et incertae sedis . Four species placed in Neodiplopeltula gen. nov. are redescribed. The following taxonomic changes are proposed: Neodiplopeltula asymmetrica (Allgen, 1935) gen. et comb. nov.; Neodiplopeltula barentsi (Steiner, 1916) gen. et comb. nov.; Neodiplopeltula bathmanni (Jensen, 1991) gen. et comb. nov.; Neodiplopeltula cuspidiboja (Leduc, 2017) gen. et comb. nov.; Neodiplopeltula indica (Gerlach, 1962) gen. et comb. nov.; Neodiplopeltula intermedia (Gerlach, 1954) gen. et comb. nov.; Neodiplopeltula obesa (Nguyen Vu Thahn, Nguyen Thahn Hien & Gagarin, 2012) gen. et comb. nov.; Neodiplopeltula onusta (Wieser, 1956) gen. et comb. nov.; Neodiplopeltula ovalis (Ditlevsen, 1928) gen. et comb. nov. and Neodiplopeltula tchesunovi (Fadeeva & Mordukhovich, 2013) gen. et comb. nov. New synonyms include: Diplopeltis asymmetricus Allgen, 1935 and Diplopeltis ovalis Ditlevsen, 1928 are synonimised with Neodiplopeltula barentsi (Steiner, 1916) gen. et comb. nov.; Diplopeltula tchesunovi Fadeeva & Mordukhovich, 2013 is synonimised with Neodiplopeltula onusta (Wieser, 1956) gen. et comb. nov.; the male of Diplopeltula cuspidiboja Leduc, 2017 is synonimised with Neodiplopeltula barentsi gen. et comb. nov. and the female with N. bathmanni gen. et comb. nov. A key to the species of Neodiplopeltula gen. nov. is provided.

Four new nematode species of the order Araeolaimida are described from the continental slope of New Zealand: Sabatieria megadena sp. n., Pararaeolaimus tetradenus sp. n., Southerniella parasimplex sp. n., and Diplopeltula cuspidiboja sp. n. The present study provides the first record of the genus Pararaeolaimus in the New Zealand Exclusive Economic Zone. Pararaeolaimus megaloamphidus Timm, 1961, Diplopeltula mollis Bussau, 1993 and Diplopeltula peruensis Bussau, 1993 are considered species inquirendae due to the incomplete nature of the original descriptions. Southerniella amblynema Bussau, 1993, Southerniella lympha Bussau, 1993, and Southerniella nojii Jensen, 1991 are transferred to the genus Intasia Tchesunov & Miljutina, 2008 due to the presence of a single anterior outsretched ovary. A key to valid Southerniella species is provided.

Two species of the nematode family Diplopeltidae are described from Skagerrak. The new genus Belgopeltula gen. nov. is proposed for Diplopeltula belgica Vincx & Gourbault, 1992 and is characterised by: amphidial fovea circular in female and double-loop-shaped in male; excretory pore located at the level of cephalic setae bases; oral opening on the dorsal side of the body; pharynx subdivided into strongly muscularised fusiform corpus and weakly muscularised narrow and long postcorpus; female didelphic with antidromously reflexed ovaries; supplements absent. Mudwigglus micramphidium sp. nov. is characterised by: a body of 0.6 mm long; cephalic sensilla 1.5 µm long; amphidial fovea loop-shaped, 8 µm long and 3.5 µm wide; gymnostom without cuticularised ring; tail elongate conoid, with subcylindrical distal part; terminal setae absent; spicules 15 µm long; gubernaculum present; two midventral precloacal setae. It is distinguished from M. macramphidium Leduc, 2013 in having shorter amphidial fovea, shorter spicules and presence of two precloacal setae. Redescription of Diplopeltis cylindricauda Allgen, 1932 is provided based on type material. Diplopeltula minuta Vitiello, 1972 is transferred to the genus Mudwigglus Leduc, 2013. Diplopeltis cylindricauda Allgen, 1932, Diplopeltula laminata Vitiello, 1972 and Diplopeltula cassidaignensis Vitiello, 1972 are transferred to the genus Pseudaraeolaimus Chitwood, 1951.

Eight species of Diplopeltoides are described from the Swedish west coast. Diplopeltoides suecicus sp. nov. has the cuticle with longitudinal striation visible only under SEM; cuticular plate underlying the cephalic cuticle around the amphid present; cephalic sensilla 4–6 µm long; amphid an inverted U-shape; wide space between amphidial branches areolated; spicules 27–31 µm long; gubernaculum with caudal apophysis. Diplopeltoides longicaudatus sp. nov. is characterized by a cuticle without longitudinal striation; cuticular plate underlying cephalic cuticle around amphid present; cephalic sensilla 13 µm long; amphid an inverted U-shape; narrow space between amphidial branches not ornamented; spicules unequal in size, 27–31 µm long; gubernaculum absent; midventral precloacal cuticular ridge present. D. grandis sp. nov. is characterized by a cuticle with longitudinal striation; cuticular plate underlying cephalic cuticle around amphid present; cephalic sensilla 18.5 µm long; amphid an inverted U-shape; wide space between amphidial branches punctate. The following taxonomic changes are proposed: Diplopeltoides asetosus (Juario, 1974) comb. nov., Diplopeltoides botulus (Wieser, 1959) comb. nov., Diplopeltoides bulbosus (Vitiello, 1972) comb. nov., Diplopeltoides lucanicus (Boucher & Helléouët, 1977) comb. nov., Diplopeltoides pumilus (Vincx & Gourbault, 1992) comb. nov. and Diplopeltoides striatus (Gerlach, 1956) comb. nov. Diplopeltoides holovachovi Fadeeva & Mordukhovich, 2013 is synonymised with Diplopeltoides pumilus comb. nov. An updated key to the species of Diplopeltoides is provided.

In the Campos Basin, 12 species of Sabatieria were collected, 2 of which were new to science. Sabatieria labium sp. nov. is characterized by well-defined lips and a spiral amphideal fovea with 4.25–4.5 narrow turns, combined with cephalic setae 3 µm long and 7–8 small, pore-shaped supplements, gradually spaced further apart anteriorly. Sabatieria verteris sp. nov. possesses 8–10 minute, pore-shaped precloacal supplements, gradually spaced further apart anteriorly, and short, slightly sclerotized spicules. Additionally, redescriptions of Sabatieria flecha, S. fidelis, S. mortenseni, S. ornata and S. paracupida are presented. The collection of additional specimens of these species allowed a re-evaluation of morphological and/or morphometric variations.

A preliminary study was conducted to record the diversity of nematode fauna in Goa during 2011-2012. For the present study 50 samples were collected from five talukas of South Goa District, covering 25 villages and 20 landscapes. Permanent slides were prepared after extraction of nematodes using Cobb’s decanting and sieving method and modified Baermann’s funnel method. The study resulted in recording 52 species of seven orders. Dorylaimida was the dominant order both in number of species and genera while the least was Araeolaimida.

A literature review reveals that 13 species are described belonging to the genus Paracomesoma Hope and Murphy, 1972. In Can Gio mangrove forest, Ho Chi Minh city, Vietnam, one new species Paracomesoma paralongispiculum n. sp. was found, which brings the number of species up to 14. This species differs from all known species of this genus by its very long spicules (12 times a.b.d) and 11–12 papillae supplements all confined within the spicular region.

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.

Two new species of the free-living marine nematode genus Deontolaimus (Leptolaimidae) are described from mangrove forests of the Can Gio Biosphere Reserve and Tien Yen, Quang Ninh, Vietnam. D. mangrovi sp. nov. is distinguished from D. papillatus de Man, 1880 and D. cangioensis sp. nov. by tail shape: conical and then elongated, without pointed tip. Deontolaimus cangioensis sp. nov. resembles D. papillatus in body shape, especially in the pointed tail terminus. D. cangioensis differs from D. papillatus in having a complicated gubernaculum with dorsally curved apophyses.

Bohra, P., Sanyal, A.K., Hussain, A., Mitra, B. (2010): Five new records of nematodes from East Antarctica. Journal of Threatened Taxa 2 (6): 974-977, DOI: 10.11609/JoTT.o2342.974-7, URL: http://threatenedtaxa.org/index.php/JoTT/article/view/511

Two new plectid species from India are described and illustrated. Plectus glandulatus sp. n. has 917-1307μm long body; strongly annulated cuticle; conspicuously large hypodermal glands; ovoid amphidial apertures; offset lip region; separate, globular, lips; thickly cuticularised, arcuate, cheilostomal walls; basal bulb with four to five paired denticulate ridges; a pair of pseudocoelomocytes located posterior to the cardia and tail with a subterminal spur and three pairs of caudal setae. Chiloplectus indicus sp. n. has 695-1041μm long body; thick, transversely annulated, cuticle; three lateral incisures; markedly offset, narrow, lip region; lips with conical apices and slightly raised papillae; inner margin of lips forming well cuticularised oral framework; prorhabdion as long as wide and comprising 20% of the stoma length; basal bulb with six pairs of denticulate ridges; paired pseudocoelomocytes located posterior to the cardia, genital tract weakly developed and tail with one median spur and two pairs of caudal setae.

Abstract Two known and one new species of Paraphanolaimus are described, viz. P. behningi from Germany, P. anisitsi from Paraguay and Germany and P. paraguayensis sp. n. from Paraguay. Paraphanolaimus paraguayensis sp. n. is characterised by 0.84-0.94 mm long body, presence of 37-44 lateral epidermal glands, strongly sclerotised and broad cylindrical stoma, swollen tail tip; female reproductive system with developed spermathecae, straight vagina; male without neck setae, 16-19 tubular supplements, two precloacal and nine to ten caudal setae, spicules 32-33 μm long, arcuate, with oval manubrium and fusiform shaft, platelike gubernaculum. Paraphanolaimus indicus and P.micoletzkyi are considered as species inquirendae. An emended diagnosis and a revised classification of Paraphanolaimus are proposed and a key to the species of the genus is provided. Aphanonchus bayensis (Keppner, 1988) comb. n. is proposed for Paraphanolaimus bayensis Keppner, 1988.

This article covers the general systematics, phylogenetic relationships, distribution and diversity of freshwater nematodes. Also included are synopses on the biology, external and internal anatomy, physiology, reproduction and feeding behavior of this widespread group of aquatic invertebrates. Discussions of their ecology include dispersal and macro and micro habitats, as well as physiological constraints, especially in regards extreme and specialized habitats. Also covered are predators and parasites of freshwater nematodes. Aside from free-living representatives, stages of invertebrate and vertebrate parasitic nematodes, especially members of the family Mermithidae, are also included. For those interested in collecting and maintaining freshwater nematodes in the laboratory, sections on sampling, extraction, fixing, mounting and culturing are also presented. Many of the areas discussed here could just as well pertain to brackish water nematodes as well as marine nematodes.

The genus Aegialoalaimus de Man, 1907 includes 12 nominal species, of which three species are considered valid, two species were transferred to other genera and seven species have uncertain taxonomic status. New species, Aegialoalaimus bratteni sp. n. was found in Skagerrak off the west coast of Sweden. It is particularly characterized by the 1.5-1.8 mm long body, short papilliform cephalic sensilla, excretory pore opening just posterior to nerve ring level, spicules that are straight in shape, supplements and gubernaculum absent, separating it from other valid species of the genus. It can be further differentiated from Aegialoalaimus elegans in having longer body (1.5-1.8 mm in A. bratteni sp. n. vs 0.8-1.3 mm in A. elegans), shape and size of spicules (straight and 22-29 µm long in A. bratteni sp. n. vs arcuate and 34 µm long in A. elegans), absence of precloacal supplements (vs seven-eight in A. elegans), absence of gubernaculum (vs present in A. elegans); from A. setosa in having shorter tail (c´=2.6-3.1 in A. bratteni sp. n. vs c´=4.2 in A. setosa), shorter cephalic sensilla (0.5-1.0 µm in A. bratteni sp. n. vs 9 µm in A. setosa), shape and size of spicules (straight and 22-29 µm long in A. bratteni sp. n. vs arcuate and 40-45 µm long in A. setosa), absence of precloacal supplements (vs eight in A. setosa), absence of gubernaculum (vs present in A. setosa); from A. leptosoma in having longer body (1.5-1.8 mm in A. bratteni sp. n. vs 0.5-0.7 mm in A. leptosoma) and other measurements, shape of spicules (straight in A. bratteni sp. n. vs arcuate in A. leptosoma), absence of precloacal supplements (vs three-five in A. leptosoma), absence of gubernaculum (vs present in A. leptosoma). Type specimens of Aegialoalaimus cylindricauda Allgén, 1933 and A. paratenuicaudatus Allgén, 1959 are redescribed and taxonomic status of these two species is re-evaluated. A taxonomic review, tabular compendium and identification key for species of the genus Aegialoalaimus are also given.

A Checklist of the Free-Living Marine Nematodes of the Iberian Peninsula, based on the literature published to date, is presented in this paper. The localities where the taxa were collected, as well as the habitats and depths where they were found, are also mentioned. All references to date provide a total of 236 species, 142 genera and 37 unidentified families. Also, the preparation of the present Checklist allowed us to clarify some errors that have been dragging on for some time and make a few clarifications, all of them based on a review of the original papers.

The genus Anonchus is revised. The genera Assia and Haconnus are considered to be synonymous with Anonchus on the basis of the morphological analysis. Additional descriptions of six species, viz. A. maculatus , A. mirabilis , A. millelacunatus , A. palaeotropicus , A. coomansi and A. pulcher are provided on the basis of type material or recently collected populations. The lectotype of A. monohystera is designated and described and the synonymy of this species with A. maculatus is confirmed. Two new species are described; A. winiszewskae sp. n. from Paraguay and A. venezolanus sp. n. from Venezuela. Several aspects of the morphology are described and the variability and diagnostic significance of the main morphological characters discussed. A study of intrageneric and suprageneric taxonomy of the genus Anonchus is presented. The subfamily Aphanolaiminae is reinstated for the genera Aphanolaimus, Aphanonchus and Paraphanolaimus and raised to family rank. The family Aphanolaimidae includes two subfamilies: Aphanolaiminae and Anonchinae. An emended diagnosis and a revised classification of Anonchus are proposed and a key to the species of the genus is provided.

Three nematode species of the genus Syringolaimus (Enoplida, Ironidae) were found in the Angola Basin (south-east Atlantic Ocean) at depths of almost 5500 m. One of them is described as new for science and the other two were initially recorded from the deep sea off the Brazilian coast and are redescribed here. Syringolaimus elegans sp. n. differs from all other species of Syringolaimus by a slimmer body (a=99 vs. 30–73) and from all species except S. ingens (nom. nud.) by its greater body length (2718 μ m vs. 760–1750 μ m), longer buccal cavity (79 μ m vs. 28–58 μ m), and longer terminal pharyngeal bulb (70 μ m vs. 53 μ m). All the Syringolaimus species together make up from 0.75 to 2.82% of all nematode individuals from all samples. Diagnoses of Syringolaimus annae Lima et al ., 2009 and S. smolae Lima et al ., 2009 are updated. An annotated list of Syringolaimus species is provided; the species annae , elegans , filicaudatus , loofi , magdae , renaudae , smolae , striatocaudatus and taniae are considered as valid, while brevicaudatus , caspersi , lichenii , marisalbi , smarigdus and venustus as species inquirendae, and gladiatus , ingens, nitidus and venustus as nomina nuda . Diagnostic characters and problems of species identification are discussed.

A new species of Domorganus, D. suecicus sp. n., is described from bottom sediments collected in Skagerrak off the westcoast of Sweden. It is characterised by its long body (1.3–1.6 mm), lateral field originating immediately posterior toamphid, excretory pore located at the level of basal pharyngeal bulb, absence of advulval sensilla, straight spicules andabsence of gubernaculum. The new species has a unique set of characters (position of excretory pore and absence of thegubernaculum) separating it from all other known species of the genus. It shows some resemblance to the previouslydescribed species D. acutus and D. subtilis in body size and most measurements, but can be easily separated from both bythe relatively longer tail, shorter spicules, position of the anterior end of the lateral field near amphid, position of theexcretory pore anterior to pharyngo-intestinal junction, and absence of gubernaculum. A tabular compendium of species of the genus Domorganus is also given.

New distribution records are given for Hemicycliophora lahiata Colbran, 1960, Helicot\lenclms africanus (Micoletzky, 1916), Scutellonema hrachyurum (Steiner, 1938), Plectus cirratus Bastian, 1865 and Ironus i^navus Bastian 1865. A check list of all the nematode species recorded from rivers in the Kruger National Park is included.

The taxonomic richness of the marine Nematoda in coastal habitats of Brazil and similarities in generic composition among them are analysed. A complete faunal list is presented, containing 11 orders, 59 families, 294 genera and 231 species, among which 1 family, 10 genera and 87 species were discovered for the first time in Brazil. Seven habitats were considered (sandy beaches, estuaries, phytal, oceanic islands, beach rocks, salt works and artificial substrates): sandy beaches had the greatest generic richness (241), followed by estuaries (142) and the phytal environment (126). Taxonomic composition was similar to that of other coastal habitats sampled worldwide, with Chromadoridae and Xyalidae the most representative families. The three major habitats (beaches, rocky shores and estuaries), showed statistically significant differences in faunas. Estuaries were the most uniform in composition.

Two new species of free‐living marine nematodes Adoncholaimus chinensis sp. nov. and Bathylaimus huanghaiensis sp. nov. from the Yellow Sea, China are described and illustrated. Adoncholaimus chinensis sp. nov. is characterized by the gubernaculum with a slender apophysis; two files of seven to eight circumcloacal setae on each subventral side of body. Bathylaimus huanghaiensis sp. nov. is characterized by a cylindrical body and smooth cutical. The buccal cavity is relatively smaller than in other species of the genus Bathylaimus. The anterior buccal cavity has only one obvious dorsal tooth. The amphids are subspiral with 1.2 turns, posterior to the base of posterior buccal cavity. They also have a long three‐jointed cephalic seta.

A new genus and species, Aphanonchus inlermedius, is described from Lake Tahoe, California. It is characterized by a finely annulated cuticle with narrow lateral field, soft cephalic setae, unispiral to irregularly circular amphids which occupy about 1/2 of the corresponding head width, stoma consisting of a narrow anterior and a wide, sclerotized posterior part. Lateral epidermal glands and pores prominent. Ventral gland lobed and associated with coelomocytes, excretory duct cuticularized opening anterior to mouth opening. Female reproductive system amphidelph, vagina with prominent sclerotization. Male with a series of tuboid supplements and a medioventral row of numerous alveoli extending to the anterior end. The new genus is intermediate between Paraphanolaimus and Anonchus. Paraphanolaimus mullipapillatus (Daday, 1905) is transferred to the new genus. The morphology of the head end and of the vaginal musculature is described in detail.

Three new species of Paraphanolaimus Micoletzky, 1922 are described, one from southern Chile, P. terrestris sp. n., is characterized by length of female, number of smooth, coarse annuli, conoid tail with tubular posterior portion, long neck region (b = < 4.5). P. latescens sp. n. from Lizard Island, Great Barrier Reef, Australia is distinguished by length of females and males, shape of tail, size of spicules and number of lateral epidermal glands (LEG). P. tahoensis sp. n. from Lake Tahoe, California, is distinguished by length of females and males, number of annuli, number and size of pairs of prominent LEGs, large oval amphids, rounded lips of vulva, perpendicular vagina, number of supplements, and size and shape of spicules and gubernaculum. Specimens of P. anisitsi Daday, 1905 from southern Chile and from the Mendocino coast of California provide further information on that species. P. micoletzkyi Khera & Chaturvedi, 1977, was described from a single female and distinguished by a set-off posterior bulb in the pharynx immediately behind the nerve ring. This character makes doubtful its placement in the genus Paraphanolaimus and the species is assigned to species inquirendae.

Three known and two new species of Aphanolaimus are described, viz. A. louisae, A. seshadrii, A. brasiliensis, A. aberrans sp. n. and A. vietnamicus sp. n. New data on the morphology and distribution of A. louisae, A. seshadrii and A. brasiliensis are given. The male of A. brasiliensis is described for the first time: it is characterised by the presence of one pair of neck setae, four tubular supplements, two precloacal and six caudal setae, 13-18 μm long spicules with oval manubrium and gradually narrowing shaft, platelike gubernaculum. Aphanolaimus aberrans sp. n. is characterised by a 495-681 μm long body, longitudinally striated cuticle, presence of 24-34 lateral epidermal glands, weakly sclerotised stoma, amphid with central elevation, lateral field starting on the third to seventh annule, oval ventral gland cell; female reproductive system with developed spermathecae, straight vagina without sclerotisations; male with one pair of neck setae, with two or three small tubular supplements and three or four caudal setae, 13-18 μm long spicules with oval manubrium and gradually narrowing shaft, plate-like gubernaculum. Aphanolaimus vietnamicus sp. n. is characterised by a 544-569 μm long body, longitudinally striated cuticle, presence of 19 lateral epidermal glands, weakly sclerotised stoma, amphid with central elevation, lateral field starting on 14th-18th annule, oval ventral gland cell; female reproductive system with developed spermathecae, straight vagina without sclerotisations; male with one pair of neck setae, with two tubular supplements and four caudal setae, 12 μm long spicules with oval manubrium and gradually narrowing shaft.

We describe two new species and provide one new species record of the family Comesomatidae from a submarine canyon habitat on the Southern Hikurangi margin, New Zealand. Vasostoma hexodontium n. sp. is characterized by having an amphideal fovea with three turns, buccal cavity with six teeth and gubernaculum with long and straight caudal apophyses. Sabatieria dispunctata n. sp. is characterized by the absence of cuticle punctations, large amphideal fovea with 4.5 turns, pharynx with posterior bulb, absence of pre-cloacal supplements, strongly arcuate and cuticularized spicules, simple gubernaculum with short caudal apophyses, and vulva opening directed posteriorly. Laimella subterminata Chen & Vincx, 2000, which was originally described from the Beagle Channel and the Magellan Strait (Chile), is recorded from the Southwest Pacific for the first time.

Two new species of Antomicron are described from bottom sediments collected in Gullmarn Fjord, west coast of Sweden. A. quindecimpapillatus sp. n. is particularly characterised by the 1390–1459 µm long body; elongate doughnut-shapedamphid; straight vagina with drop-shaped sclerotizations; female without sensilla in pharyngeal region and without sup-plements; male with two pairs of setiform sensilla in pharyngeal region, 15 tubular and no alveolar supplements, one pairof precloacal and four pairs of caudal setae, 26.0–29.5 µm long spicules. A. lorenzeni sp. n. is particularly characterisedby the 603–676 µm long body; an inverted U-shaped amphid; straight vagina without sclerotizations; female without sen-silla in pharyngeal region and without supplements; male without sensilla in pharyngeal region, two tubular and nine al-veolar supplements, one pair of precloacal and four pairs of caudal setae, 23 µm long spicules. Additional information onthe males of Antomicron pellucidum, A. elegans, A. pratense and A. intermedius is provided. A taxonomic review, tabular compendium and identification key of species of the genus Antomicron are also given.

Detailed descriptions of six species of Plectus reported for the first time from India are given on the basis of LM and SEMobservations. Plectus geophilus de Man, 1880, P. aquatilis Andrassy, 1985, P. parvus Bastian, 1865, P. minimus Cobb,1893, P. magadani Kuzmin, 1979 and P. communis Butschli, 1873 are described and illustrated. The salient morphologicalcharacters of the species are given. The taxonomy of the genus has been discussed along with the status of species pre-senting a great degree of morphometric overlap and continuous variation. An emended diagnosis of the genus is provided with incorporation of relatively consistent and less variable characters.

Descriptions are given oi'0.\'vdirusgangeticusS\c\dic\i, 1966, Laimydorus africanus spec. nov. and Rhaljclolainms terrestris De Man, 1880, recorded for the first time from South Africa. New distribution records are given for Dorylaimellus {Axodorylaimellus) caffrae (Kruger, 1965). Additional information is given and morphometric data are tabulated and where appropriate, illustrations are also given.

A nematological survey of Belgium revealed four species of Aphanolaimus, two known ones, A. attentus de Man, 1880 and A. aquaticus Daday, 1894, and two new ones. A. pseudoattentus n.sp. resembles A. attentus in many respects but can easily be distinguished by the greater body length, the head shape, the shape of the amphideal fovea and the longer cephalic setae. A. deconincki n.sp. is characterized by its head shape, shape of amphideal fovea, posterior origin of lateral field and large number of body annules.

Across 88 sites 9 species were found, with Anaplectus granulosus at 56 sites, Plectus parietinus at 47, P. longicaudatus at 30, P. parvus at 15, P. cirratus and Wilsonema otophorum at 11, P. armatus and A. porosus at 4, and Tylocephalus auriculatus at 1 site. A key to Anaplectus males is given. For nine sites mean length of female A. granulosus is negatively correlated with mean annual air temperature. The most diverse fauna comprised six species in Kaitoke silt loam; it appears that faunal diversity increases with higher rainfall. Species apparently coexist through separation in size and time. Tylocephalus was only found in soils with a thermic soil temperature regime.

Aphanolaimus louisae sp.n. from mountain lakes on Mt. Kenya is described and figured in detail. Examination by scanning electron microscopy revealed some interesting morphological characters, such as the structure of the amphideal fovea, extremely small mouth opening, cuticular striation, lateral field, cuticular pores and setae and male supplements. A. louisae most closely resembles A. aquaticus Daday, 1894, but differs in the number of preanal supplements and shape of the spicules. A specimen from Zaire comes close to the new species and is described as Aphanolaimus sp. Finally A. microlaimus De Coninck, 1935 is redescribed on the basis of the type material.

Fourteen soil-inhabiting species of nematodes, including two new species, are recorded from the Canadian high Arctic. Microlaimus arcticus n. sp. and Hofmaenneria hazenensis n. sp., are described and illustrated. Two genera, Cylindrolaimus and Achromadora, are revised. Most of the recorded species are illustrated and measurements presented. Taxonomic keys to species in the genera Bastiania, Achromadora, Microlaimus, and Trischistoma are presented. The taxonomic position of the genus Nannonchus Cobb, 1913 is discussed.