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Die Interstitielle Fauna im Elbe-Aestuar. Verbreitung und Systematik
... Of them, two species, P. faber Wieser, 1956 andP. tricuspidata Wieser, 1956, were described from Chile; Promonhystera albigens Riemann, 1966 was described from the North Sea (Venekey et al. 2014), later transferred to Daptonema by Hopper (1968), but recently returned to Promonhystera on account of the setiform inner labia sensilla (Yu & Xu 2015); and the latest species discovered from New Zealand has been described as Promonhystera crinita Leduc & Zhao, 2023. In this study, we extend our knowledge of marine nematode diversity and distribution in the South China Sea by describing two new species of Promonhystera from intertidal sediments of the Hainan Island. ...
... Promonhystera albigensis Riemann, 1966 Promonhystera crinita Leduc & Zhao, 2023 Promonhystera faber Wieser, 1956 Promonhystera fluctispicula sp. nov. ...
... , except a, b, c, c′ and a.b.d). Data cited from Leduc & Zhao (2023), Riemann (1966) and Wieser (1956). Abbreviations are as follows: a: the ratio of body length to maximum body diameter; b: ratio of body length to pharynx length; c: ratio of body length to tail length; c.b.d.: corresponding body diameter; c′: ratio of tail length to cloacal or anal body diameter; sp/a.b.d.: ratio of spicule length to cloacal body diameter. ...
Two new species of free-living marine nematodes from the littoral sediment of the South China Sea are described as Promonhystera papilla sp. nov. and Promonhystera fluctispicula sp. nov. Both new species are characterized by striated cuticle; circular amphideal fovea; anterior sensilla in two circles, inner labial sensilla setiform; funnel-shaped buccal cavity; elongated spicules and conico-cylindrical tail. P. papilla sp. nov. is different from all known species of the genus by longer body length (more than 2.1mm versus less than 1.5 mm in other species), longer spicules (sp/a.b.d. = 4.1–4.6 versus ≤ 2.7) and males with three papilliform precloacal supplements and one small postcloacal papilla (versus absence) and gubernaculum boot-shaped. P. fluctispicula sp. nov. is similar to P. tricuspidata Wieser, 1956 in having similar waved spicules but differs from the latter species by tail conico-cylindrical (versus conical) and simple plate-like gubernaculum without tooth (versus gubernaculum with four distal teeth).
... Gubernaculum relatively large, various authors as reported in the review by . Riemann (1966) recognized two forms of the species, one stout and one elongated, which differed in body dimensions, tail shape, and the structure of borders delimiting the buccal cavity compartments, but which both had four-chambered buccal cavities. Lorenzen (1969) also distinguished between stout and elongated forms of T. marinus, which differed in body dimensions but showed different numbers of buccal cavity compartments (three in the stout form and four in the elongated form). ...
... hypothesized that these two forms may are in fact different species, with the stout form corresponding to T. marinus and the elongated form corresponding to T. gracilis (Ditlevsen, 1919) Filipjev, 1927. The Pāuatahanui Inlet specimens appear most similar to the stout form of Riemann (1966) and Lorenzen (1969) in general body dimensions and tail shape but comparing buccal cavity structure is not straight-forward due to the variation we observed among the Pāuatahanui Inlet specimens, as well as inconsistencies between the descriptions of Riemann (1966) and Lorenzen (1969). ...
... hypothesized that these two forms may are in fact different species, with the stout form corresponding to T. marinus and the elongated form corresponding to T. gracilis (Ditlevsen, 1919) Filipjev, 1927. The Pāuatahanui Inlet specimens appear most similar to the stout form of Riemann (1966) and Lorenzen (1969) in general body dimensions and tail shape but comparing buccal cavity structure is not straight-forward due to the variation we observed among the Pāuatahanui Inlet specimens, as well as inconsistencies between the descriptions of Riemann (1966) and Lorenzen (1969). ...
Full text available for free at: https://niwa.co.nz/oceans/niwa-biodiversity-memoirs
The phylum Nematoda Cobb, 1932, also known as roundworms, is the most abundant metazoan taxon in aquatic sediments worldwide, as well as one of the most diverse. Despite their ubiquitous distribution, our knowledge of nematode taxonomy and diversity in New Zealand, and in particular, free-living species in marine sediments, remains very limited. The nematode fauna of New Zealand’s marine environments, ranging from the most accessible beaches to abyssal plains, remains poorly known, with the total biodiversity of the free-living marine nematode fauna in the New Zealand Exclusive Economic Zone estimated at several thousand species. Prior to this work, the total number of free-living marine nematode species known from the New Zealand region was 190 species.
Unlike previous recent NIWA Biodiversity Memoirs which focus on a particular taxon group rather than a specific region, this work focuses on the nematode fauna of Pāuatahanui Inlet, a drowned river valley and one of two arms of Te Awarua-o-Porirua Harbour in the Wellington region. The main reason for this regional approach is that the New Zealand marine nematode fauna remains largely uninvestigated, and very few specimen collections are available. The most efficient way to increase our knowledge of free-living marine nematode taxonomy in New Zealand is therefore to begin describing the fauna from an easily accessible environment. Pāuatahanui Inlet was chosen because, while it has high ecological and cultural significance, it is also subject to anthropogenic impacts associated with changes in surrounding land use and pollution. A better knowledge of the nematode fauna will thus bring a more complete understanding of the ecological value of this ecosystem and should facilitate ecological monitoring in the future.
A total of 55 nematodes species belonging to two classes, eight orders, 19 families and 41 genera were found. Thirty-nine of the most common species are described here, 26 of which are new to science, four of which are new records for New Zealand, and seven of which [Bathylaimus cf. australis Cobb, 1894; Tripyloides cf. marinus (Bütschli, 1874) de Man, 1886; Chromadora cf. nudicapitata Bastian, 1865; Chromadorina germanica (Bütschli, 1874) Wieser, 1954; Cobbia trefusiaeformis de Man, 1907; Terschellingia cf. longicaudata de Man, 1907; Litoditis cf. marina (Bastian, 1865) Sudhaus, 2011] are cosmopolitan species or species complexes. Together, these species are to be called ‘Ngā toke o Parumoana’: ‘ngā toke’ refering to the worms, and ‘parumoana’ refering to the tidal areas of Te Awarua-o-Porirua which consist of two elements, i.e., the brown mud flats (paru) and the sea (moana).
In addition to line drawings and light micrographs, scanning electron micrographs and molecular sequences are provided for 12 and 28 of the species described here, respectively. Eight seemingly cosmopolitan species, some of which are likely to be cryptic species complexes, were found to occur in the inlet, but the identity of the Pāuatahanui Inlet populations could not be confirmed due to a lack of published molecular sequence data. It is highly likely that additional nematode species not listed here will be found in the inlet as sampling continues in the future. Currently, free-living nematodes are estimated to represent about 40% of the total infaunal diversity in Pāuatahanui Inlet.
... L. aberrans was first discovered in Oresund and thereafter redescribed from Kiel Bight (Gerlach, 1964). Riemann, 1966Riemann, 1966Platt & Warwick, 1988: 306-307, Figs 140 a-e. ...
... L. aberrans was first discovered in Oresund and thereafter redescribed from Kiel Bight (Gerlach, 1964). Riemann, 1966Riemann, 1966Platt & Warwick, 1988: 306-307, Figs 140 a-e. ...
... Our specimens correspond well to the original diagnosis of Riemann ( 1966), except for some minor details in males (indices a = 7.8-10.7 and b = 9.3-11.7 versus respectively 12-14.4 and 12.7-13.9) and females (body length 483-612 µm versus 695 µm). ...
Eight species of the families Selachinematidae and Richthersiidae are found in the White Sea, North Russia. The new species, Gammanema anthostoma sp. n., is distinguished by the peculiar chelostomal rugae protruding from the mouth. Its males differ from the males of all Gammanema species in the lack of supplementary organs. Females of G. anthostoma sp. n. differ from those of the two Gammanema species whose males are hitherto unknown: from the females of G. mediterraneum Vitieello, 1970 in the lacking long somatic setae, value of the b index and three times longer body; and from females of G. cancellatum Gerlach, 1955 in the lenth ratio of the outer labial and cephalic setae. Six swpecies (Choniolaimus panicus, Gammanema fennicum, G. rapax, Halichoanolaimus robustus, Latronema aberrans, Richthersia inaequalis) are recorded from the White Sea for the first time. G. fennicum is ressurected as a good species and its male is described for the first time; this species is strongly sexually dimorphic. G. rapax is a very variable species or even a group of species, as its redescriptions differ in important details: its wide distribution needs confirmation. In males of Latronema aberrans, the spermatozoa are filiform unlike rounded spermatozoa of other selachinematids.
... Cuticle in the head region thickened ( Figure 2H); tight spiral turn of the amphid; conspicuous dimorphism sexual in the size of amphideal fovea; pre-cloacal supplements papilloid ( Figure 3F); and gubernaculum distally not dilated nor dentate (Figures 4B1,C2; Gerlach, 1953a;Riemann, 1966). The species can be distinguished from each other by the form of buccal sensilla and the shape of the gubernaculum. ...
... The Paracyatholaimoides species seems to have restricted distribution, except by P. multispiralis, that was registered in the Coastal Zone and Continental Shelf habitats in five ecoregions nested in two different realms, Temperate Northern Atlantic (Gerlach, 1953a,d,e,f;Somerfield et al., 2007;Ellis et al., 2010) and Tropical Atlantic (Pérez-García et al., 2020). The systematic value of the characteristics on which the genus erection was based is controversial and a taxonomy review is needed (Riemann, 1966). Cuticle without lateral differentiation (Figure 2A); pre-cloacal supplements papilloid or as setae-like organs half inserted into the body (Figures 3F,G); and gubernaculum hardly dilated at the distal end, without pronounced teeth (Figures 4C3,H3), but sometimes plate-shaped with denticles ( Figure 4J9; Platt and Warwick, 1988;Tchesunov, 2008). ...
... Species classified in the Paracyatholaimus genus were recorded in all oceans and latitudes and were found in all types of habitats. P. intermedius has a remarkable distribution: it is a mainly brackish species (e.g., de Man, 1880;Warwick, 1971a), however, it was also recorded from marine (e.g., Kreis, 1963;Gerlach, 1965), freshwater (e.g., Riemann, 1966;Gagarin and Nguyen Vu Thanh, 2012;Gusakov and Gagarin, 2012), and terrestrial environment (Loof, 1961;Nzeako et al., 2019). Three species were found exclusively in the Freshwater habitats: P. lewisi Coomans, Vincx and Decraemer, 1985, P. paramonovi, and P. truncatus. ...
Nematoda is a very species-rich phylum that has successfully adapted to almost all types of ecosystems. Despite their abundance and ecological importance, the taxonomic knowledge of nematodes is still limited and the identification of species is not trivial. In Cyatholaimidae, a relatively common and abundant family of free-living nematodes, the identification of organisms is challenging due to the overlap of some generic diagnoses and the absence of updated systematic reviews. Here we systematically reviewed the knowledge about the family diversity, providing a list of valid species, the diagnostic characters to genus level, and the geographical and habitat distribution of species. The review systematized a total of 619 records. The occurrences were classified into biogeographic ecoregions and habitats. Cyatholaimidae includes 211 valid species, classified in 20 genera. The genera can be differentiated based on six diagnostics characters, namely: pattern of cuticle ornamentation; number of longitudinal rows of pore-complex in cuticle; structures of the buccal cavity; presence/absence of pharyngeal bulb; pre-cloacal supplements aspect; and the shape of gubernaculum. Cyatholaimidae includes mainly marine species, mostly occurring in the Coastal Zone. Four and three species were registered in freshwater and terrestrial habitats, respectively, all classified in the genus Paracyatholaimus. About 38% of the valid species occur in more than one type of habitat, under very different environmental conditions, suggesting a broad niche. The occurrence of congeneric species in different habitats types indicates that, throughout the evolutionary history of the family, multiple ecological shift events have occurred. The family occurs worldwide in 74 ecoregions, and the majority of the records and species are in the North Sea and Western Mediterranean. Most species are endemic to one ecoregion, and examples of broadly distributed ones may be a result of misidentifications or cases of long-distance dispersal, especially for those associated with biological substrates.
... The species Pomponema loticum has possibly been documented by Riemann (1966), but previously identified as Pomponema sp. or Anaxonchium litorium Cobb, 1920. Subsequently and based on studies of Riemann (1966), Lorenzen (1972) synonymized Anaxonchium litorium with Pomponema and named the species as Pomponema loticum. ...
... The species Pomponema loticum has possibly been documented by Riemann (1966), but previously identified as Pomponema sp. or Anaxonchium litorium Cobb, 1920. Subsequently and based on studies of Riemann (1966), Lorenzen (1972) synonymized Anaxonchium litorium with Pomponema and named the species as Pomponema loticum. Four years later, Riemann (1976) described a new species of Pomponema, Pomponema carinatum, but the author observed that the characters of P. carinatum and P. loticum were very similar and stated that he had confused the described type of P. carinatum with P. loticum. ...
... Longicyatholaimus clavicaudatus Schuurmans Stekhoven, 1935syn. Haustrifera clavicaudata (Schuurmans Stekhoven, 1935 Riemann, 1966Pomponema compactum Lorenzen, 1972 Pomponema concinnum (Wieser, 1954) Lorenzen, 1972 syn. Haustrifera concinna Wieser, 1954Pomponema coomansi Vincx, 1981 Pomponema corniculata Gourbault, 1980 Pomponema cotylophorum (Steiner, 1916) Lorenzen, 1972syn. ...
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.
... The species Pomponema loticum has possibly been documented by Riemann (1966), but previously identified as Pomponema sp. or Anaxonchium litorium Cobb, 1920. Subsequently and based on studies of Riemann (1966), Lorenzen (1972) synonymized Anaxonchium litorium with Pomponema and named the species as Pomponema loticum. ...
... The species Pomponema loticum has possibly been documented by Riemann (1966), but previously identified as Pomponema sp. or Anaxonchium litorium Cobb, 1920. Subsequently and based on studies of Riemann (1966), Lorenzen (1972) synonymized Anaxonchium litorium with Pomponema and named the species as Pomponema loticum. Four years later, Riemann (1976) described a new species of Pomponema, Pomponema carinatum, but the author observed that the characters of P. carinatum and P. loticum were very similar and stated that he had confused the described type of P. carinatum with P. loticum. ...
... Longicyatholaimus clavicaudatus Schuurmans Stekhoven, 1935syn. Haustrifera clavicaudata (Schuurmans Stekhoven, 1935 Riemann, 1966Pomponema compactum Lorenzen, 1972 Pomponema concinnum (Wieser, 1954) Lorenzen, 1972 syn. Haustrifera concinna Wieser, 1954Pomponema coomansi Vincx, 1981 Pomponema corniculata Gourbault, 1980 Pomponema cotylophorum (Steiner, 1916) Lorenzen, 1972syn. ...
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.
... Two species were subsequently included in Trichotheristus; Thristus (Trichotheristus) paramirablis (Gerlach, 1955) Gerlach, 1955] by Wieser (1959) and Th. (T.) hamatus Gerlach, 1956by Riemann (1966. ...
... Wieser & Hopper (1967). The former was later included as Trichotheristus paramirablis (Gerlach, 1955) in the checklist by Gerlach & Riemann (1973) and the latter, Th. hamatus sensu Riemann, 1966, was synonymized with Metadesmolaimus aduncus Lorenzen, 1972in Lorenzen (1972. In the same year, Vitiello (1967) erected a new species, Theristus (M.) hirsutus Vitiello, 1967, in the subgenus Mesotheristus. ...
... n. in order to avoid making a homonym with D. articulatum Lorenzen, 1977. (Bütschli, 1874) Lorenzen, 1977 Theristus (T.) hamatus sensu Riemann, 1966.......................Metadesmolaimus aduncus Lorenzen, 1972 ...
Daptonema chonispiculum sp. n. and D. phuketense sp. n. are described from the Ban Pa Khlok seagrass bed, Phuket Province, Thailand. Daptonema chonispiculum sp. n. is characterized by spicules with funnel-shaped proximal ends, and D. phuketense sp. n. is unique in having the third caudal gland filled with fibrous contents. Each new species also differs from most related species in body length, de Man’s indices, length of the cephalic setae and somatic/cervical setae, distance of the amphids from the anterior of the body, and length of the spicules. The new species most closely resemble D. hirsutum, D. platonovae, and D. robustum, with similar body lengths, long cervical setae located in the anterior pharyngeal region, small amphids, L-shaped spicules and a gubernaculum with a long dorso-caudal apophysis. Regarding the taxonomic status of Daptonema and Trichotheristus, we agree with the synonymization of Trichotheristus with Daptonema by Tchesunov (1990), based on taxonomic review of Trichotheristus and a comparison of the diagnostic features separating the genera. We propose a new combination, Daptonema galeatum comb. n., and a new name, Daptonema nearticulatum sp. n. for Trichotheristus articulatus Huang & Zhang, 2006.
... Similar epidermal chords have been reported in Daptonema trabeculosum (G. Schneider, 1906) by Schneider (1906), Riemann (1966) and Lorenzen (1977) and in D. conicum (Filipjev, 1922) by Lorenzen (1977), though they did not refer to the epidermal cells as such but described the transverse boundaries of each 2 adjoining epidermal cells as "Trabekel" (Schneider, 1906) or "Trabekeln" (Riemann, 1966); terms which mean a cytoplasmic bridge between the cuticle and alimental canal. According to Riemann (1966), this feature of the epidermal chords has no taxonomic significance because "Trabekeln" did not always exist in his specimens. ...
... Similar epidermal chords have been reported in Daptonema trabeculosum (G. Schneider, 1906) by Schneider (1906), Riemann (1966) and Lorenzen (1977) and in D. conicum (Filipjev, 1922) by Lorenzen (1977), though they did not refer to the epidermal cells as such but described the transverse boundaries of each 2 adjoining epidermal cells as "Trabekel" (Schneider, 1906) or "Trabekeln" (Riemann, 1966); terms which mean a cytoplasmic bridge between the cuticle and alimental canal. According to Riemann (1966), this feature of the epidermal chords has no taxonomic significance because "Trabekeln" did not always exist in his specimens. ...
... Schneider, 1906) by Schneider (1906), Riemann (1966) and Lorenzen (1977) and in D. conicum (Filipjev, 1922) by Lorenzen (1977), though they did not refer to the epidermal cells as such but described the transverse boundaries of each 2 adjoining epidermal cells as "Trabekel" (Schneider, 1906) or "Trabekeln" (Riemann, 1966); terms which mean a cytoplasmic bridge between the cuticle and alimental canal. According to Riemann (1966), this feature of the epidermal chords has no taxonomic significance because "Trabekeln" did not always exist in his specimens. In the seagrass beds that have been studied , besides D. hyalocella sp. ...
Daptonema hyalocella sp. n. and D. setihyalocella sp. n. are described from the Ban Pa Khlok seagrass bed, Phuket Province, Thailand. These new species are characterized by the epidermal chords consisting of large cells with a transparent appearance, as in D. conicum (Filipjev, 1922) and D. trabeculosum (G. Schneider, 1906). The key characteristics of D. hyalocella sp. n. are the peculiar epidermal chords, loose S-shaped spicules with no proximal cephalation, an indistinct gubernaculum with a lateral piece, and two terminal setae. For D. setihyalocella sp. n., the key characteristics are similar peculiar epidermal chords, but in this case with the L-shaped spicules having proximal cephalation, a distinct gubernaculum with dorsal apophysis and lateral piece, and four terminal setae.
... Among Bolbolaimus species, B. chitwoodi (Gerlach, 1950) Jensen, 1978 wieseri (Hopper, 1961) Jensen, 1978 andB. major (Gerlach, 1950) Jensen, 1978 B. crassiceps (Gerlach, 1953) Jensen, 1978 Cobb, 1920 (Nobsca Beach, Woods Hole, Massachusetts, uSA) B. riemanni (Riemann, 1966) Jensen, 1978 B. teutonicus (Riemann, 1966) Jensen, 1978 B. tongaensis Leduc, 2016 (Tonga Trench, Southwest Pacific) B. wieseri (Hopper, 1961) Jensen, 1978, Chile) Bolbolaimus major sp. nov. ...
... Among Bolbolaimus species, B. chitwoodi (Gerlach, 1950) Jensen, 1978 wieseri (Hopper, 1961) Jensen, 1978 andB. major (Gerlach, 1950) Jensen, 1978 B. crassiceps (Gerlach, 1953) Jensen, 1978 Cobb, 1920 (Nobsca Beach, Woods Hole, Massachusetts, uSA) B. riemanni (Riemann, 1966) Jensen, 1978 B. teutonicus (Riemann, 1966) Jensen, 1978 B. tongaensis Leduc, 2016 (Tonga Trench, Southwest Pacific) B. wieseri (Hopper, 1961) Jensen, 1978, Chile) Bolbolaimus major sp. nov. ...
Bolbolaimus major sp. nov. is described from Rizhao coast along the Yellow Sea. The new species is characterized by relatively large body size, cuticle strongly annulated, six outer labial sensilla setiform, four cephalic setae long, buccal cavity wide with one large dorsal tooth and two small subventral teeth, amphidial fovea unispiral shaped oval in males and circular in females, spicules curved with swollen proximal end, gubernaculum with anterior-hooked dorso-caudal apophysis, and tail conical with short spinneret. A phylogenetic analysis of maximum-likelihood and Bayesin inference based on rDNA sequences confirms the taxonomic position of Bolbolaimus major sp. nov. within the family Microlaimidae. Tree topology in Microlaimidae shows genus Microlaimus as polyphyletic group and genera in Microlaimidae are closely related.
... 7 a-e; El Salvador. 12 Paracyatholaimus pentodon Riemann, 1966. Riemann, 1966, Abb. 31 a-e; North Sea. ...
... a fig. 107 Coomans, Vincx & Decraemer, 1985. Coomans et al., 1985 fig. 2 A-F; Solomon Islands, freshwater pool on a coral island; no males described. 10 Paracyatholaimus occultus Gerlach, 1956. Gerlach, 1956Kiel Bay. 11 Paracyatholaimus paucipapillatus Gerlach, 1955. Gerlach, 1955, Abb. 7 a-e; El Salvador. 12 Paracyatholaimus pentodon Riemann, 1966. Riemann, 1966, Abb. 31 a-e; North Sea. Platt & Warwick, 1988: 282, fig. 128; East and West Scotland. 13 Paracyatholaimus pesavis Wieser & Hopper, 1967: 268-269, pl. XVI, fig. 32 a-e; Florida. 14 Paracyatholaimus proximus (Bütschli, 1874 Wieser & Hopper, 1967. Wieser, 1959 fig. 35 a-c (=Longicyatholaimus quadriseta Wieser, 1959, nec L. quadriseta Wies ...
Three new nematode species were found in the Angola Basin (south-east Atlantic Ocean) at depths of about 5500 m. Paracyatholaimus diva sp. nov. (Cyatholaimidae) is characterised by outer labial and cephalic setae of about 3–5 μm, multispiral amphidial fovea with six turns in males and four turns in females situated at the level of the dorsal tooth, buccal cavity armoured with only one prominent dorsal tooth, tail consisting of anterior conical and posterior slender cylindrical half portions, and six preanal midventral setose supplementary organs. Paracyatholaimus diva sp. nov. is most similar to Paracyatholaimus rotundus Gerlach, 1964 but differs by slightly longer body (936–1176 μm versus 705 μm), tail shape (with clearly narrowed posterior half versus conical), six versus four supplementary organs of different shape. The genus Paracyatholaimus Micoletzky, 1923 is briefly reviewed. The genus now includes twenty-four valid species. Five species are considered as species inquirendae, mainly because of inadequate type material lacking adult stages and/or incomplete descriptions. A pictorial guide for identification of the valid species of Paracyatholaimus is provided. Pomponema proximamphidum sp. nov. shares subapical position of the amphidial fovea and distinct lateral differentiation of the somatic cuticle with five Pomponema species: P. concinnum Wieser, 1954, P. corniculata Gourbault, 1980, P. mirabile Cobb, 1917, P. multipapillatum Filipjev, 1922 and P. stomachor Wieser, 1954 but differs from them by tail length, longer posterior cylindrical portion of the tail, relative width of the amphidial fovea, position of the ventral pore and lesser number of supplementary organs. Desmodora striatocephala sp. nov. is well characterized by a combination of very large amphidial fovea occupying nearly the entire lateral surface of the cephalic capsule and thickened midventral preanal cuticle with a few supplementary papillae inserted therein in males. D. striatocephala sp. nov. differs from related species D. cuddlesae Inglis, 1963 and to some lesser degree with D. inflexa Wieser, 1954 with shorter body, relative tail length, bigger size of the amphidial fovea and lesser number of supplementary papillae.
... Rectum length slightly shorter than body diameter in the anus area. abebei (according to : Muthumbi et Vincx 1999) bahari (according to : Muthumbi et Vincx 1999) chitwoodi (according to : Chitwood 1937) crassiceps (according to : Gerlach 1953) pellucidus (according to : Cobb 1920) riemanni (according to : Riemann 1966) teutonicus (according to : Riemann 1966) wieseri (according to : Wieser 1954) obesus sp. n. ...
... Rectum length slightly shorter than body diameter in the anus area. abebei (according to : Muthumbi et Vincx 1999) bahari (according to : Muthumbi et Vincx 1999) chitwoodi (according to : Chitwood 1937) crassiceps (according to : Gerlach 1953) pellucidus (according to : Cobb 1920) riemanni (according to : Riemann 1966) teutonicus (according to : Riemann 1966) wieseri (according to : Wieser 1954) obesus sp. n. ...
An illustrated description of the nematode Bolbolaimus obesus sp. n. from a mangrove forest of the Yen River estuary, Vietnam is given. Bolbolaimus obesus sp. n. is close to B. abebei Muthumbi et Vincx 1999 and B. bahari Muthumbi et Vincx 1999, but differs from both by the shorter body, strongly sclerotized body walls of the cheilostoma, a different position of the amphidial fovea, and longer gubernaculum.
... The description was based on individuals collected in sand at 5-12 cm depth, by McIntyre and Eleftheriou (1968) from Highland County, Firemore Bay, Loch Ewe, on the west coast of Scotland. Additional specimens collected from the North Sea, at Germany (several localities of the Elbe Estuary in sand) and England (North Yorkshire County: Filey Beach and Stoup Beck Beach) by Riemann (1966) and Pollock (1971), respectively, were used for comparison in the original description. Subsequently, the species was recorded from many other localities of the northeast Atlantic Coast (again from Scotland by McIntyre and Murison 1973and Morgan and Lampard 1986a, b, and Ireland by Morgan 1980, from the Irish Sea (Isle of Man by Moore 1979) and from the Celtic Sea (England by Hummon 1994 and France by Jørgensen et al. 2010). ...
... The only relevant difference concerns the fourth leg sense organ, which is shorter in Portuguese specimens. It is interesting to remark that, contrary to all the other northeast Atlantic populations that were collected in the intertidal at 0 m depth, only Portuguese and German populations were sampled in subtidal sediments (both between 10 and 15 m b.s.l., although German specimens were collected in an estuarine habitat; Riemann 1966;Kaczmarek et al. 2015). Potentially different ecological requirements as well as morphological differences such as the presence of shorter leg sense organs on the fourth leg pairs, the presence of small tubercles on primary clavae and the small size of specimens recorded in the Lusitanian sea province (Portugal), and also smaller appendages (internal cephalic cirri, cirri E and primary clavae) mentioned by Pollock (1971) when comparing the German and Scottish populations, are small differences favouring the hypothesis that B. tubernatis may be a complex of species, justifying the need for further investigations. ...
Specimens of Batillipes tubernatis Pollock, 1971 collected from the Portuguese coast (Lusitanian sea province) indicated a considerable southward extension in the distribution of the species along the northeast Atlantic Ocean. Based on the examination of these specimens and those of Pollock’s collection from the type locality (Scotland), it can also be concluded that the redescription of B. tubernatis based on specimens from the Gulf of Mexico (tropical northwest Atlantic Ocean) does not correspond to that species. Several differences, namely in the shape of cephalic appendages, toe discs and pattern of cuticular sculpture, clearly distinguish specimens of B. tubernatis from those collected in the Gulf of Mexico that certainly belong to a new unnamed species. Moreover, the examination of specimens previously collected in the southwest Atlantic Ocean (Brazil) and attributed to B. tubernatis showed that they belong to other undescribed new Batillipes species, suggesting that B. tubernatis does not occur in that region. Additionally, the only record from the temperate northwest Atlantic Ocean attributed to this species cannot be assigned to B. tubernatis either. Therefore, a clarification about the current taxonomic status of B. tubernatis is provided and a short characterisation of the habitat of this species on the Portuguese coast is presented. As the occurrence of the species outside the northeast Atlantic Ocean is questioned, this work should renew the discussion about trans- and cis-Atlantic distributions of meiobenthic species. © 2018 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag GmbH Germany, part of Springer Nature
... Onyx cobbi sp. n. is similar to O. perfectus Riemann, 1966 by its very long cephalic and somatic setae and by the number of supplements but it differs by the sexual dimorphism in the amphidial fovea, lacking in O. perfectus Riemann, 1966 Onyx paradimorphus sp. n. ...
... Onyx cobbi sp. n. is similar to O. perfectus Riemann, 1966 by its very long cephalic and somatic setae and by the number of supplements but it differs by the sexual dimorphism in the amphidial fovea, lacking in O. perfectus Riemann, 1966 Onyx paradimorphus sp. n. ...
Six new species of the genus Onyx are described from different coastal zones in Vietnam based on samples collected between 2004 and 2010. Onyx cangionensis sp. n. is characterised by the fact that males have 14-16 equal-sized and equal-distantly arranged sigmoidal precloacal tubular shaped supplements. Onyx blomei sp. n. is characterised by sexual dimorphism in the shape of the amphidial fovea. The male has an atypical amphid with posterior part spiral shaped with 2.5 turns and anterior part hook shaped, whereas the amphidial fovea in the female is simply multispiral with 2.25 turns. Onyx orientalis sp. n. is characterised by its very long cephalic setae and the presence of 18 light-refractive, slightly S-shaped, precloacal tubular supplements in the males. Onyx cobbi sp. n. is also characterised by its sexual dimorphism in the shape of the amphidial fovea: an elongated loop in the male and a multispiral in the female. There are 15 slightly S-shaped, precloacal supplements. The anterior supplement is half the size of the others. Onyx paradimorphus sp. n. is characterised by a multispiral amphidial fovea, spicules regularly bent, strongly cuticularised, 15 S-shaped supplements and 5 papillae with setae within the spicules region. Onyx mangrovi sp. n. is characterised by 17-23 supplements with a complex structure: anterior part is sigmoidal-shaped, posterior part is hook-shaped and by its very short tail with dorsally curved tip.
... complexa,. But it differs from N. bilineata in body length (864-943 μm vs 567-852 μm), cephalic setae length (7-8 μm vs 4-6 μm), amphidial fovea width (50-58% vs 45% corresponding body diameter), spicules shape and length (L-shaped and widened in the middle portion, 28-31 μm vs arcuate and gradually narrowing, 23-26 μm), and gubernaculum length (19-22 μm vs 15-18 μm); differs from N. izhorica in cephalic seta length (7-8 μm vs 14 μm), pharynx shape (posterior bulb obvious vs posterior bulb weak), spicules length (28-31 μm vs 31.5-34.5 μm), gubernaculum shape (distal end tapered vs distal end with anterior-laterally curved tip) (Riemann 1966); differs from N. complexa in body length (864-943 μm vs 642 μm), spicules shape (curved and L-shaped with middle portion widened vs L-shaped even in width), gubernaculum shape (boat-shaped vs dorsal part slenderly extended), distance between precloacal supplements (10-15 μm vs 2-5 μm) (calculation based on Gerlach 1953b: fig. 11); differs from N. poecilosoma in body length (864-943 μm vs 1900-2000 μm), cephalic setae length (7-8 μm vs 10-14 μm), spicule length (28-31 μm vs 60-65 μm), gubernaculum shape (boat-shaped vs distal tip with small tooth) (de Man 1893). ...
Two new species of Hypodontolaiminae, Dichromadora media sp. nov. and Neochromadora parabilineata sp. nov. , were isolated and described from the Yellow Sea, China. Dichromadora media sp. nov. is characterized by four long cephalic setae, the amphidial fovea transverse oval in the male and slit-shaped in the female, the pharynx with a single posterior bulb, spicules curved and distally bifurcated, gubernaculum jointed, four (1+3) precloacal supplements papilliform, and the tail conical elongated with a short spinneret. Neochromadora parabilineata sp. nov. is characterized by the buccal cavity with one large hollow dorsal tooth and two small subventral teeth, the pharynx with an obvious posterior bulb, spicules L-shaped and widened medially, gubernaculum boat-shaped, seven cup-shaped and equidistant precloacal supplements, and a long and gradually tapering tail. The phylogenetic analysis of maximum likelihood and Bayesian inference based on rDNA sequences confirmed the taxonomic positions of Neochromadora parabilineata sp. nov. and Dichromadora media sp. nov. within Hypodontolaiminae. Tree topology in Hypodontolaiminae shows the genera Neochromadora , Dichromadora , Ptycholaimellus , and Spilophorella as polyphyletic groups, and the genus Chromadorita as a paraphyletic group.
... I. prismatolaima [5] was described only from males found at the Atlantic Shore of the USA by Cobb. I. riemanni [14] was found by Riemann in 1966 [15] in the Elbe estuary and in Kandalaksha Bay (the White Sea) by Platonova and Mokievsky in 1994 [14]. The new species is the first recorded species within Ironella in the Chinese sea area. ...
Three new nematode species belonging to the order Enoplida were discovered in the muddy and sandy sediment along the Shandong peninsula coast of the Yellow Sea during a biodiversity investigation of marine nematodes in the Yellow Sea. They are named Belbolla octobulba sp. nov., Ironella gracilis sp. nov. and Oxystomina longiseta sp. nov. Belbolla octobulba sp. nov. is characterized by having eight pharyngeal bulbs; spicules arcuate, broad and even; gubernaculum with a pair of dorso-caudal apophyses, about a third of the length of spicule; and two winged precloacal supplements. Ironella gracilis sp. nov. differs from known species by body slender, buccal cavity divided into conical vestibulum and cylindrical posterior portion, three sclerotized teeth located in the vestibulum; both circles of outer labial setae and cephalic setae 10 µm apart; elongated spicules weakly arcuate with central strip and cephalate proximal end; gubernaculum conical without apophysis; and a tubular precloacal supplement with a long seta at its anterior end. Oxystomina longiseta sp. nov. can be distinguished from other known species by the relatively long outer labial setae and cephalic setae; arcuate spicules expanded proximally with a median rib; gubernaculum small and oblong; and two unequal precloacal supplementary setae, anterior one short, posterior one very long. Updated keys to eighteen species of Belbolla and keys to four species of Ironella are given.
... These observations reveal again that some macrodasyids had overcome physiological barrier to adapt to life in freshwater environment. Apart from this case, the description of the macrodasyid Redudasys fornerise from a Brazilian inland water body (Kisielewski, in print), the finding of Marinellina flagellata in the Austrian river psammon (Ruttner-Kolisko, 1955; see also Kisielewski, in print ) as well as the record of Turbanella cornuta from a very low-salinity water in the Elbe estuary (Riemann, 1966) could be mentioned. ...
... 253 (209 ± 8) μm, Q 2 = 190-258 (209 ± 6) μm. 13 Lake (Schneider, 1925) and Grand Ploener Lake (loc. nov.), both in the system of Ploener lakes; Stechlinsee Lake in Saale River basin (Altherr, 1968); estuary of Elba River (Riemann, 1966); Wollengster Lake, env. Bremerhaven (Riemann, 1978). ...
The lectotype of Tobrilus aberrans is designated from the Gulf of Finland, Russia. Descriptions of populations of T. aberrans from Grand Ploener Lake (Germany) and Tiberias Lake (Israel) are given.
... In small streams in Germany, only about one-third of the species are restricted to streams, with most species frequently identified in surrounding terrestrial habitats as well (Niemann et al., 1996;Christl, 2008). Many species in the lower reaches of rivers have also been detected in adjacent estuarine habitats (Riemann, 1966). Vertical exchanges with hyporheic and rhizosphere nematofauna are also possible, although this has not been well studied so far. ...
Mean nematode abundance ranges from ca. 1 000 to 10 000 000 individuals per m2.
Species richness usually range from 10 to 100, but >200 species per habitat can be found over the year.
Total biomass is usually between 1 and 100 mg wet weight per m2 (up to 10 g).
Deposit feeders, feeding mainly on bacteria, typically dominate aquatic habitats.
Species structure reacts to different abiotic and biotic drivers.
Species distributions form patterns evident at microscopic to global scales.
... The formation and functioning of benthic communities in the estuarine areas is largely determined by the high spatiotemporal heterogeneity of environmental conditions (Remane, 1934;McLusky, 1981). These patterns were also well demonstrated for meiofauna (Smol et al., 1994;Coull, 1999;Udalov et al., 2005), particularly for nematode communities (Nicholas et al., 1992;Riemann, 1966; Soetaert et al., 1995). At the same time, the development of plant communities is of great significance for fauna (Castel et al., 1989;Boström et al., 2006;Liao et al., 2015). ...
The seasonal changes in density, species biodiversity and trophic groups of free-living marine nematodes forming assemblages in tropical seagrass meadows have been studied in the Tien Yen River estuary (Gulf of Tonkin, South China Sea). Significant variations of the features of the nematode communities in the horizontal scale and in time were found. In the rainy season (October), the nematode density noticeably decreased, and the species composition and dominant species, as well as such parameters of assemblages as diversity and structure, changed as compared to April. A total of 71 nematode species were recorded from the studied area but only four species have been found at all stations in both seasons. The reasons for this are the high spatial heterogeneity of environmental conditions and their pronounced seasonal variations. Environmental conditions (granulometric composition of the bottom sediments, water temperature and salinity) were characterised by pronounced differences between stations as well as seasons. The precipitation (heavy rainfalls) in the intertidal zone of the estuary is the main factor responsible for seasonal changes of nematode assemblages.
... Gerlach, 1958: 72; as Mesacanthion diplechna, Kiel Bay, silt, 8 m deep. Riemann, 1966: 186 North Sea, sand. Boucher, 1977as Mesacanthion diplechma Southern, 1914, one male, three females and six juveniles, Pierre Noire (Western Channel), infralittoral sands]. ...
A new species of the genus Mesacanthion Filipjev, 1927 was discovered during a survey of natural beaches of Jeju Island in South Korea. The new species Mesacanthion jejuensissp. nov. shares general morphology of the genus such as the outer labial and cephalic setae being situated at the middle of cephalic capsule, well-developed mandibles with two columns united by a curved bar, and three equally sized and shaped teeth shorter than the mandibles. The new species belongs to a group of Mesacanthion species in which spicules are shorter than two anal body diameters. The new species is most closely related to M. pannosum , first discovered in Puget Sound, Washington, in terms of having enlarged cervical setae flap at the end of cephalic capsule, spicules which are shorter than 2 anal body diameter, both supplementary organ and gubernaculum. It can be distinguished from M. pannosum by its stronger inner labial setae, longer outer labial setae, and difference in the index value of b and c’. Along with the description of Mesacanthion jejuensissp. nov., the genus Mesacanthion Filipjev, 1927 is bibliographically reviewed and revised. Including the new species, a total of 48 species are described within the genus; 39 which are valid; eight which are considered to be species inquirenda due to misplacement of genus and poor description; one which is considered nomen nudum. An updated diagnosis of the genus is provided along with a compiled tabular key comparing different diagnostic morphological characters of all valid species, as well as a pictorial key consisting of 21 species with spicules shorter than two anal body diameters.
... suggested that P. acridentata is a dubious species that could be a synonym to P. neapolitana or P. maculata but we prefer to consider P. acridentata as species inquirendum because there is only a female described and based on this specimen it is not possible to determine its taxonomic position. P. arabica and P. quinquepapilata are also considered as species inquirenda following the suggestion of and Riemann (1966), respectively. also proposed a key based on the presence and absence of ocelli combined with the orientation of the dorsal tooth. ...
Chromadoridae is a widespread family of mostly free-living marine nematodes. This systematic review provides for each genus: a historical background, an updated diagnosis and a list of species. Our review recognizes 37 valid genera, 395 valid species, 57 descriptions without enough morphological information for accurate identification (species inquirenda) and 10 species incerta sedis. We also recognize 21 species as nomena nuda. Additionally, polytomous keys were constructed for the subfamilies and for the genera of the three major subfamilies (Chromadorinae, Euchromadorinae and Hypodontolaiminae) using the most important diagnostic characters. A phylogenetic analysis based on rDNA sequences of species available in the GenBank was also conducted. Phylogenetic trees based on the 18S and 28S rDNA confirmed the classification into three subfamilies (Spilipherinae, Hypodontolaiminae and Chromadorinae), despite the absence of defined synapomorphies. Phylogenetic relationships at lower taxonomic level are problematic given the large number of sequences not identified to species level.
... however, the relative size of toes and details of the arrangement among feet were not referred by Renaud-Debyser (1959). Specimens from England, Filey Beach and Stoup Beck Beach, Yorkshire, collected by Pollock (1971) and from germany, Elbe Estuary (Riemann 1966) attributed to B. phreaticus, differed from the original description in some morphometric aspects and in having lateral body projections often present (Pollock 1971). Moreover, Pollock (1971) noticed that in English specimens, the middle toes (toes 3 and 4) on feet of legs IV were equal in length. ...
Five species of Batillipes Richters, 1909 were collected from subtidal sediments of the Portuguese coast. Two of them, B. algharbensis sp. nov. and B. lusitanus sp. nov., are new to science. Batillipes algharbensis sp. nov. differs from all the other Batillipes species in having the middle toes 3 on the fourth feet longer than middle toes 4 and by the presence of rounded lateral body projections between legs III and IV. Batillipes lusitanus sp. nov. has the middle toes of the fourth feet equal in length, but it exhibits a dorsal cuticular ornamentation, constituted by large pillars, similar to the cuticle of B. adriaticus Grimaldi de Zio, Morone De Lucia, D’Addabbo Gallo & Grimaldi, 1979 and B. roscoffensis Kristensen, 1978. However, contrary to B. adriaticus, the caudal apparatus of B. lusitanus sp. nov. is a roundish cuticular expansion and B. roscoffensis lacks caudal apparatus. Batillipes adriaticus and B. phreaticus Renaud-Debyser, 1959 are new records for Portugal. Based on the examination of specimens of B. phreaticus collected at the Portuguese coast and their comparison with type material of this species and also of B. littoralis Renaud-Debyser, 1959, the toe arrangement patterns in species of Batillipes are clarified and a new identification key to species of this genus is provided.
... Nematodes were mounted individually onto slides for iden-tiWcation (Cook et al., 2005). The Wrst 30 nematodes of seven samples were identiWed to the lowest taxonomic level possible (Bastian, 1865;Riemann, 1966;Gerlach andRiemann, 1973/1974;Lorenzen, 1977;Platt, 1983;Warwick, 1983, 1988;Warwick et al., 1998). We found that genomic DNA degraded during storage in glycerol (Meldal, 2004) and so storage in glycerol for desiccation and identiWcation was kept to a maximum of two weeks. ...
... Nematodes were mounted individually onto slides for iden-tiWcation (Cook et al., 2005). The Wrst 30 nematodes of seven samples were identiWed to the lowest taxonomic level possible (Bastian, 1865;Riemann, 1966;Gerlach andRiemann, 1973/1974;Lorenzen, 1977;Platt, 1983;Warwick, 1983, 1988;Warwick et al., 1998). We found that genomic DNA degraded during storage in glycerol (Meldal, 2004) and so storage in glycerol for desiccation and identiWcation was kept to a maximum of two weeks. ...
Phylogenetic reconstructions of relations within the phylum Nematoda are inherently difficult but have been advanced with the introduction of large-scale molecular-based techniques. However, the most recent revisions were heavily biased towards terrestrial and parasitic species and greater representation of clades containing marine species (e.g. Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, Enoplida, and Monhysterida) is needed for accurate coverage of known taxonomic diversity. We now add small subunit ribosomal DNA (SSU rDNA) sequences for 100 previously un-sequenced species of nematodes, including 46 marine taxa. SSU rDNA sequences for >200 taxa have been analysed based on Bayesian inference and LogDet-transformed distances. The resulting phylogenies provide support for (i) the re-classification of the Secernentea as the order Rhabditida that derived from a common ancestor of chromadorean orders Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, and Monhysterida and (ii) the position of Bunonema close to the Diplogasteroidea in the Rhabditina. Other, previously controversial relationships can now be resolved more clearly: (a) Alaimus, Campydora, and Trischistoma belong in the Enoplida, (b) Isolaimium is placed basally to a big clade containing the Axonolaimidae, Plectidae, and Rhabditida, (c) Xyzzors belongs in the Desmodoridae, (d) Comesomatidae and Cyartonema belongs in the Monhysterida, (e) Globodera belongs in the Hoplolaimidae and (f) Paratylenchus dianeae belongs in the Criconematoidea. However, the SSU gene did not provide significant support for the class Chromadoria or clear evidence for the relationship between the three classes, Enoplia, Dorylaimia, and Chromadoria. Furthermore, across the whole phylum, the phylogenetically informative characters of the SSU gene are not informative in a parsimony analysis, highlighting the short-comings of the parsimony method for large-scale phylogenetic modelling.
... However, the genus Desmodora became less common in the Candlagan Creek (Nicholas and Stewart 1993) characterized by a soft, tenacious, silty clay sediment (median grain size of 0.03 mm). Riemann (1966) described the nematode communities along the Elbe in Germany and found that the polyhaline region of the Elbe is distinguished from the mesohaline zone by the presence of Desmodoridae. They also mentioned that with progressive increase in grain size (and decrease in silt-clay content), the number of Desmodoridae and other families increased in the marine shallow subtidal area. ...
Nematode communities in eight Mekong estuaries were investigated during the dry season. The aim of the study was to identify the structure and the diversity of the communities in relation to the main environmental characteristics. In each estuary, three to four intertidal sampling stations were identified at regular distances from the mouth to up to 45 km land inward. The nematode communities showed a strong correlation with sediment composition and to a lesser degree with chlorophyll a concentrations. Multivariate analysis resulted in the identification of four types of communities. We identified two types of Desmodora communities in the sandy mouth stations and two types of Parodontophora communities in the silty sand stations. One of the silt associated communities showed a preference for higher chlorophyll a concentrations, resulting in higher densities and higher diversity, mainly of monhysterid species. Because of the strong association between community structure and sediment composition, nematodes are a meaningful tool for monitoring changes in their environment. In case their community deviates from what is expected based on sediment, it may serve as an early warning for disturbance.
... When describing the changes in the meiobenthos characteristics with the salinity gradient, most of the authors deal with the diversity and species structure of individual groups, mainly nematodes [17,19,20,22,31,36]. In so doing, they present no analysis of the quantitative distribution of the meiobenthos. ...
The quantitative distribution of meiobenthos is studied at 16 stations in the estuary of the Chemaya River (Kandalaksha Bay, White Sea) in the salinity range from 0 to 20‰. The overall meiobenthos density varies from 167 to 2356 ind./10 cm2. The taxonomic structure of the meiobenthos changes with the water desalination. In the seaward part, nematodes dominate (on the average, 85% of the total meiobenthos abundance). At salinity values lower than 10‰, the proportion of nematodes falls down to 50%, while the share of ostracodes increases up to 45% of the total abundance and 76% of the total biomass of meiobenthos. It is shown that the leading factor controlling the distribution of the nematode densities is the substrate type. On silty grounds, their density is greater than on sandy substrates; the negative influence of desalination is manifested only at salinity values lower than 3‰. There is a confident negative correlation between the density of ostracodes and the salinity; the former is independent of the other factors measured. The density of harpacticoids features a confident positive relation with the salinity and the content of the silty fraction. A comparison with the data from selected European estuaries shows the general distribution pattern of the densities of the major meiobenthos groups. In the salinity range from 30 to 3-7‰, there is no relation of the nematode and harpacticoid densities to the salinity; their distributions are governed by a series of other factors depending on the individual estuary. With a further fall in the salinity, the nematode and harpacticoid densities significantly decrease. The reasons for this kind of phenomenon are discussed.
... Some authors (Schneider, 1939) even did not see a necessity in discriminating these species. On the other hand, Riemann (1966) found in the Elbe estuary two close but different forms of Tripyloides that shared a four-chambered construction of the stoma. He denoted them as T. marinus 'plumpe Form' [stout form] and T. marinus 'schlanke Form' [slim form]; the latter quite possible was T. gracilis. ...
Three new nematode species of the order Enoplida were found in a degrading mangrove biotope in the Bay of Nha Trang, Central Vietnam. Admirandus belogurovi sp. n. (Oncholaimidae), a second species of the genus, differs from the only other species, A. multicavus Belogurov et Belogurova, 1979, in having shorter spicules (41-49 vs 71-110 //m) and some measurements, as well as presence of a small midventral preanal supplementary papilla. Diagnosis of the genus Admirandus Belogurov et Belogurova, 1979 is emended. Tripyloides caudaensis sp. n. (Tripyloididae) is close to a group of species T. gracilis (Ditlevsen, 1918), T. marinus (Butschli, 1874) and T. pallidas Tchesunov, 1981 with partly overlapped measurements and differs from them in shape of the tail consisting of distinct proximal conical and distal slender cylindrical portions and from T. pallidus additionally by oviparity vs viviparity. An annotated list of eleven valid species and a pictorial key for identification of Tripylodes species are given. Litinium subterraneum sp. n. (Oxystominidae) is characterised by the position of the amphideal fovea closely behind the circle of twelve anterior setae and presence of two preanal supplementary papillae. Litinium subterraneum sp. n. differs from the related L. aequale Cobb, 1920, Litinium sp. 1 and Litinium sp. 2 (both latter unnamed species were found in mangroves of Vietnam, Quang Ngo Xuan et a!., 2008) in body length, relatively longer tail, position of the amphideal fovea, relative pharynx length, different distance from the cephalic apex to the ventral pore. Some data on microscale distribution of three species in mangrove intertidal zone are provided.
... calathiJera;Wieser, 1954b -N. brevisetosa), while the last two are characterized by the large dorsal tooth (see Steiner, 1921a, Gerlach, 1951, Riemann, 1966Timm, 1961 -N. nitida), moreover, N. trichophora is equipped with the long cephalic setae (14 .um ...
A new ice-associated species of Xyalidae family, Daptonema gelida sp. n., is described from the first-year fast sea ice of the Ermolinskaya Inlet, White Sea, Russia. The new species of Daptonema is a morphologically distinct species from other species of the genus. Daptonema gelida sp. n. is characterized by (1) elongated, slender body, (2) short, evenly distributed throughout the body somatic setae, (3) circular amphideal fovea, (4) thin and strongly curved, L-shaped spicules with round-shaped manubrium, (5) gubernaculum with short dorsal-caudal apophysis by triangular-shaped outline, (6) post-vulval uterine sac present, and (7) two short terminal setae. We barcoded partial 18S rRNA gene sequences from the new sympagic species. Phylogenetic reconstructions showed that the specimen of Daptonema gelida sp. n. formed a distinct lineage with high support among other Daptonema species and was genetically related to D. carnulentum, D. setosum, D. hirsutum, Metadesmolaimus sp. and Daptonema spp. We provided a list of valid Daptonema species, including key morphological characteristics of males, and additionally reviewed 30 species inquirenda.
Thoracostomopsidae is a family of free-living marine nematodes that has three subfamilies (Thoracostomopsinae, Trileptiinae and Enoplolaiminae). Most species descriptions within this family are very old and lack indication of important morphological details, so this article aims to fill this gap in the literature. This taxonomic review provides a list of all valid species, as well as species inquirenda, nomina nuda and synonyms, for each genus. Our review recognizes 16 valid genera, 193 valid species, 47 species inquirendae and three species as nomen nudum. Additionally, taxonomic dichotomous keys were constructed, modified or updated for each genus, as well to the subfamilies, using the most important diagnostic characters.
The present study provides an updated species list of free-living marine nematodes reported from coastal India (Coasts and Islands) based on the thorough consultation of literature published from 1956 to 2022. This exercise resulted in a total of 617 valid species belonging to 266 genera, 48 families, 21 superfamilies and 9 orders. Class Chromadorea comprises 487 species represented by 205 genera, while class Enoplea includes 130 species belonging to 61 genera. The most common family was Xyalidae, with 76 species and the least common families having a single species each were represented by Aegialoalaimidae, Rhadinematidae, Aphanolaimidae, Rhabditidae, Pandolaimidae and Rhabdodemaniidae. The checklist provides a robust framework for the distribution and biogeography of free-living marine nematodes from the Indian waters and could be used to relate with marine ecosystems of other countries.
Morphology, biology and taxonomy of the nematode family Ceramonematidae Cobb, 1933 are summarised and reviewed. Plesiomorph-apomorph polarities of cuticle sculpture, cephalic sensilla pattern, amphid shape are revealed with use of the out-group comparison and ontogenetic observations. The genera Ceramonema and Pselionema are distinguished by the most apomorph character states; both genera combined comprise the greatest number of species, of the widest overall ecological range. The other ceramonematid genera display more plesiomorph character states and contain much less speces; these are strictly confined to coars sand. Ceramonematidae are related to the families Diplopeltoididae sensu Tchesunov (1990) and Tarvaiidae. The family Ceramonematidae consists of two subfamilies: Ceramonematidae with the genera Ceramonema (= Ceramonemoides, = Cyttaronema), Dasynemella (=Leptodasynemella), Dasynemoides (=Dasynemelloides), Metadasynemella (=Dictyonemella), and Metadasynemoides, and Pselionematinae with the genera Pterygonema and Pselionema (= Pselionemoides). Modified diagnoses of the family, subfamilies and genera are given. Separation of higher ceramonematid taxa is based largely on features of body cuticle annulation as well as on anterior sensilla pattern, while cephalic ratio and finer details of body annulation are important for species discriminaton. Annotated lists of species are given for each genus. The genus Ceramonema is subdivided into two subgenera, Ceramonema s. str. (body cuticular annules with zygapophyses) and Proceramonema subg. n. (body annules devoid of zygapophyses). New species from the With Sea (Ceramonema fluctuosum sp. n., C. marisalbi sp. n., C. mokievskii sp. n., Dasynemoides crassus sp. n., Metadasynemoides labiatus sp. n., Pselionema concinnum sp. n., P. mirabile sp. n.) are described. Dasynemella riemanni Haspeslagh is recorded for the first time the With Sea. The description of Pselionema simplex De Coninck from the White Sea is supplemented with notes on juveniles.
The article provides the description of Monhystera curvicaudata sp. nov., a new species of free-living freshwater nematode from a water reservoir in Rajastan state, India. The new species differs from the morphologically similar M. pseudomacrura Khera, 1971 from India in the structure of the gubernaculum without apophysis and position of vulva. Morphological characters of the genus Monhystera are discussed; a key to males of the Monhystera species is given.
A new free-living marine nematode Onyx disparamphis sp. n. (Nematoda, Desmodorida) is described from sandy littoral of Jeju Island, South Korea. The new species differs from all other Onyx species by the unusual amphideal fovea morphology in males (elongated loop). O. disparamphis relates to O. balochinensis , and O. brevispiculatum by having simple non-double terminal pharyngeal bulb and relatively small and straight, non-sigmoid supplementary organs, but differs from them by smaller body length, shorter cephalic setae, smaller terminal pharyngeal bulb, smaller spicules, number of supplementary organs and tail shape expressed as ratio tail length/anal diameter. The genus Onyx is revised with updated genus diagnosis, and an annotated list of 23 valid species is presented. Onyx ferox is considered species inquirenda because the species is known only from a sole immature female specimen, while within Onyx, the males provide the most important distinguishing characters such as enlarged and complicated amphids, supplementary organs and copulatory spicules. For species identification, a pictorial key consisting of illustrations of simplified icons of male heads and posterior body sections, as well as a table of the most important morphometric and numerical characters are provided. Geographical distribution and habitat specifity of Onyx species is analysed briefly.
Until recently, the system of the family Xyalidae was extremely complicated. The characters of the genera Theristus, Cylindrotheristus, Mesotheristus, Pseudotheristus, Mongolotheristus, and others were mixed up. Many species changed their generic assignment more than once. The most recent revision (Venekey et al. 2014) resulted in the fact that in intracontinental water bodies two species only preserved their independence: Daptonema and Sacrimarinema. Genera Cylindrotheristus, Mesotheristus, Mongolotheristus, Penzancia were partially reduced to synonyms of Daptonema. The basic character in taxonomy of genera is terminal setae. This cannot be used in some cases as some individuals in some populations lack terminal setae. Development of the system of the family Xyalidae and genus Daptonema, in particular, is possible under consideration of such characteristic as spicule form and presence of tail papillae. The hermaphrodite specimen of D. borkini sp. n. is discussed separately. The article provides an identification key to intracontinental species of the genus Daptonema. The key shows the species to be found in intracontinental water bodies. The species recorded in rivers (as a rule, in estuaries and lower parts of rivers) are not taken into account, as they seem to be the marine species which are capable to survive in significantly desalinated water. The article provides the description of new species D. borkini sp. n., which is similar in morphology to D. salinae Gagarin et Gusacov, 2014 and D. limnobia Wu et Liang, 2000. The key is supplemented with the Table of the main characteristics of all intracontinental species (males) of the genus Daptonema.
Background
Adoncholaiminae is one of the seven subfamilies in the free-living aquatic nematode family Oncholaimidae. Nematodes in Adoncholaiminae are found from various water environment of the world. However, a checklist of all Adoncholaiminae species including full literature, especially information of experimental (not taxonomic) works, has not been updated for more than 40 years.
New information
A revised checklist of the subfamily Adoncholaiminae of the world is provided. It contains 31 valid and 13 invalid species names in four genera with synonyms, collection records, and full literature from 1860's to 2015 for each species. A literature survey of total 477 previous papers was conducted in this work, and 362 of them are newly added to checklist.
Morphological descriptions of two species of the genus Theristus Bastian, 1865 belonging to group flevensis, found in the hypersaline water bodies of the Crimean Peninsula, are presented. Theristus siwaschensis sp. n. is morphologically closest to T. flevensis Schuurmans Stekhoven, 1935, T. parambronensis Timm, 1952, T. macroflevensis Gerlach, 1954, T. metaflevensis Gerlach, 1955, but differs from them by the structure of the reproductive system in females, number of cephalic setae and size of spicules. Specimens of T. flevensis found in the Lake Chersonesskoye are similar to the re-description of a large forms of T. flevensis from Chile by Murhy (1966) and Caspian Sea by Chesunov (1981). However, it differs from the Caspian Sea species by having larger amphids, longer cephalic setae and spicules. T. pratti Murph & Canaris, 1964 and T. ambronensis Schulz, 1937 are synonymized with T. flevensis.
Synonchium iranicum sp. n. and Richtersia bispinata sp. n. are described from the Persian Gulf and their relationships investigated using SSU phylogenetic analyses. Synonchium iranicum sp. n. is characterised by a buccal cavity with three equally sized mandibles, each with five small teeth, a rounded tail with three distinct caudal glands and distinct duct, males without gubernaculum and supplements, and short spicules. Richtersia bispinata sp. n. is characterised by multispiral amphids with 3.0-3.5 turns in males and 2.0-2.5 turns in females, cuticle with numerous, irregularly arranged, simple spines in the cervical region, 20-25 longitudinal rows of double spines in the mid-body region, 15-25 longitudinal rows of simple spines in the tail region, and the left spicule markedly longer than the right one. We provided the first near-full-length small subunit ribosomal DNA (SSU rDNA) sequences for both newly described species, as well as cytochrome c oxidase I ( COI ), and provided D2-D3 expansion segments of large subunit ribosomal DNA (LSU rDNA) sequence for the new species of Richtersia . Our SSU phylogenetic analyses confirmed the placement of Synonchium iranicum sp. n. within the Selachinematidae, and suggested that the selachinematids may form a distinct clade from other chromadorids Our phylogenetic analyses indicated that Richtersia should not be classified within the Selachinematidae as suggested by some authors. Instead, we propose that Richtersia should be placed within the Desmodorida. Although Richtersia differs from Desmodorida in the arrangement of cephalic sensilla, it shares the golden body colouration characteristic of desmodorids in glycerin preparations, the same structure of genital branches in both males and females, and similar cuticular ornamentation to some desmodorid genera (notably Desmodorella ).
During a survey of intertidal zones at beaches on Jeju Island, two species belonging to the family Thoracostomopsidae were discovered. One new species, Enoploides koreanus sp. nov. and one known species, Epacanthion hirsutum Shi & Xu, 2016 are reported. Along with morphological analysis, mitochondrial cytochrome oxidase c subunit 1 (mtCOI) sequences and 18S rRNA sequences of the species were also obtained and used to check relative p-distance and phylogenetic positions. While most species of Enoploides have long spicules, the new species belongs to a group of Enoploides with short spicules < 150 µm). Of the seven species with short spicules, the new species is most closely related to E. disparilis Sergeeva, 1974. They both have similar body length, fairly similar sized and shaped spicules with small gubernaculum running parallel to distal end of spicule, and an index value of b. The new species can be distinguished from E. disparilis by having pre-anal supplementary organ with short conical tail, while E. disparilis lacks pre-anal supplementary organ and has a long conico-cylindrical tail. Along with the description of the new species, the genus Enoploides Ssaweljev, 1912 is bibliographically reviewed and revised. Of 45 species described to date, 27 are now considered valid, 16 species inquirendae due to inadequate descriptions and ambiguity of the material examined, along with two cases of nomen nudum. With this review, we provide an updated diagnosis and list of valid species, a tabular key comparing diagnostic characters of all valid species, and a new complete key to species. One known species, Epacanthion hirsutum Shi & Xu, 2016, is reported in Korea for the first time. The morphology agrees well with the original description provided by Shi & Xu, 2016. As they had already reviewed the genus at the time of reporting four Epacanthion species, we provide only a description, depiction, and measurements for comparison purposes.
Sediments were collected at fifteen stations in five transects at Chetumal Bay (June and December 1995). Sediments were medium and fine sands with 15.62% organic matter. In June, 2 239 individuals represented 20 families and 37 genera; in December 1 426 individuals represented 21 families and 35 genera. Neotonchoides, Desmodora, Bathylaimus, Pseudochromadora, Desmolaimus, Chromadorina and Steineria were the most abundant. In both months the same transect had the highest abundance and richness (957 and 744 individuals, 28 and 25 genera, respectively). The lowest abundance in a transect was 48 individuals and six genera. Diversity fluctuated among 0.53 and 2.53 beles/ind. In general, the genus composition;in Chetumal bay is homogeneous. The noteworthy occurrence of marine genera in this brackish environment shows their adaptability.
Sedimente werden auch als “Gedachtnis des Gewassers” bezeichnet, da sie fur viele uber die Wasserphase eingetragene Schadstoffe eine Senke darstellen oder aus ihnen Schadstoffe remobilisiert werden. Fur die okotoxikologische Bewertung von Sedimenten finden auch zunehmend Biotests mit Nematoden und Gastropoden Anwendung. Nematoden (Fadenwurmer) sind im benthischen Okosystem von besonderer Bedeutung, da sie die arten- und individuenreichste Organismengruppe im Benthos darstellen. Zusammenfassend wird als zentrale Frage der Einfluss der Sedimentbeschaffenheit auf zwei verschiedene Biotestorganismen, Caenorhabditis elegans und Potamopyrgus antipodarum, sowie auf die Zusammensetzung einer ausgewahlten Biozonose untersucht und die Einbindung in ein Bewertungskonzept diskutiert.
Keywords:
Biotestorganismus;
Caenorhabditis elegans;
Fadenwurm;
Nematoden;
Potamopyrgus antipodarum;
Sediment;
Zwergdeckelschnecke
The composition of the genus Neotobrilus was revised and new synonyms were established. Descriptions of a new species Neotobrilus sinensis sp.n. from Taiwan and a number of species from new localities are given. Some morphological characters as taxonomie ones are proposed. A species identification key is given.
The groundwater fauna of the Piani Eterni karstic area was surveyed in 2004-2007. Piani Eterni is a 14 km2 karstic plateau, ranging from 1700 to 1900 m a.s.l., located inside a national Park (dolomiti Bellunesi) in the Southern limestone Alps. the Pi- ani Eterni complex is the largest and deepest cave system in the dolomites and currently includes over 17 km path length, with a maximum depth of 971 m below the surface. the groundwater fauna, collected from pools, rivulets and small lakes in the vadose zone of Piani Eterni complex and the nearby Isabella cave includes 27 species (11 nematoda, 7 Annelida, 7 crustacea and 2 dip- tera). Ten species are stygobionts, and five of them are new to Science. The importance of Diptera in this subterranean karstic sys- tem is noteworthy; several larvae of the chironomid Eukiefferiella gracei group were found both in groundwater bodies of Piani Eterni complex and in a spring (Fontanon) which likely drains part of the aquifer, suggesting that this stygoxene chironomid may be considered as a “biological tracer”. Some other stygoxene species (most of nematoda and Annelida and some copepoda) live in wet soil, mosses, and interstitial habitats as well as in some surface environments; they are probably recent (i.e. post-glacial) col- onizers of the cave system. the presence of stygobionts (37% of the fauna) in an area completely covered by the Alpine glaciers during Pleistocene is noteworthy.
the presence of a possible relict fauna in this area may be explained either by a re-colonization following the retreat of Würmi- an glaciers, or by their survival in the deep groundwater aquifer during the Quaternary glaciations. Finally, the observed habitat seg- regation of subterranean species within the caves studied, together with a narrow range of variation of water chemistry, indicating a homogeneity of physico-chemical parameters, suggests that habitat complexity may have played a major role, together with his- torical factors, in shaping the groundwater biodiversity in this cold, oligotrophic cave system.
Three new nematode species of the order Monhysterida were found in the Molloy Deep (Fram Strait, Arctic Ocean) at a depth over 5000 m. Sphaerolaimus micropapillatus sp. n. (Sphaerolaimidae) is characterised by the position of the amphids at the level of the gymnostom or stegostom; arched spicules of moderate length, with elongate, handle-like manubria and without a prominent gubernacular apophysis and three to five preanal supplementary papillae. Sphaerolaimus micropapillatus sp. n. differs from the related species S. glaphyrus Vitiello, 1971 and S. profundus Vitiello, 1971 by length of the body, subcephalic setae and spicules. Males of Daptonema curvispicula sp. n. (Xyalidae) possess strongly curved spicules, while females are distinguished by an oblique muscular vagina and absence of any spermatheca. Daptonema curvispicula sp. n. also differs from all related species in morphometry. Eleutherolaimus minutus sp. n. (Linhomoeidae) is the smallest species of the genus and is distinguished by a set of features such as short cephalic setae, position of the amphids well posterior to the buccal cavity and position of the ventral pore just posterior to the nerve ring. Eleutherolaimus minutus sp. n. differs from related species E. stenosoma de Man, 1907 by having a smaller body and organs and the position of ventral pore posterior to the nerve ring. A taxonomic review of the genus Eleutherolaimus Filipjev, 1922 is provided. Eumorpholaimus Schulz, 1932 is considered to be a junior synonym of Eleutherolaimus Filipjev, 1922. The genus Eleutherolaimus includes fourteen valid species. Eleven species are qualified as species inquirendae, mainly because of inadequate type material lacking adult stages and/or incomplete descriptions. A pictorial key for the identification of valid Eleutherolaimus species is presented.
This chapter is an attempt to bring together the studies of nematode diversity in terrestrial, freshwater aquatic and marine environments, and to synthesize these into some sort of general hypotheses. Such hypotheses can then be used as the bases for a range of other scientific activities, including biomonitoring and hypothesis testing. The effects of many of the variables in studies of nematode diversity, such as methods used, resolution or scope of studies, and measures of diversity are discussed first. With this background, studies on nematode diversity are then summarized and compared at a general level. Finally, hypotheses of the general patterns and processes of nematode diversity are discussed. These general patterns form the natural background for biomonitoring: to evaluate any effect of an environmental change one must know the situation expected without the change, including the expected magnitude and direction of the effects of environmental change.
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