First records of known endoparasitic species of Pseudempleurosoma Yamaguti, 1965 (Monogenoidea: Dactylogyridae) from tetraodontid and rachycentrid fish off the northern coast of the Yucatan Peninsula, Mexico

Monogenoideans infecting the rectum of the wild checkered puffer fish, Sphoeroides testudineus (Tetraodontidae), and the pyloric ceca of the cultured cobia, Rachycentron canadum (Rachycentridae), from the northern coast of the Yucatan Peninsula, Mexico, were morphologically identified as Pseudempleurosoma carangis Yamaguti, 1965 and Pseudempleurosoma gibsoni Santos, Mour?o and Cárdenas, 2001 (Dactylogyridae), respectively. Morphometric comparison between the paratypes of P. carangis and those from S. testudineus showed that the latter differ only in the length of the body, germarium, and dorsal anchors. Similarly, a small form of P. gibsoni based on body size was detected in the present study. These metric differences may be attributable to the host effect, i.e., S. testudineus/R. canadum versus Caranx lugubris (Carangidae) (type host of P. carangis) from Hawaii and Paralonchurus brasiliensis (Sciaenidae) (type host of P. gibsoni) from Brazil, or by the degree of maturity, or both. In view of these considerations, new illustrations and several supplemental observations for P. carangis and P. gibsoni are provided. The present findings also represent new geographical records, and new sites of infection, e.g., rectum and pyloric ceca, for species of Pseudempleurosoma, and the first known endoparasitic monogenoideans infecting tetraodontid and rachycentrid fishes in Mexico.     

The status of Acleotrema Johnston & Tiegs, 1922 and Heteroplectanum Rakotofiringa, Oliver & Lambert, 1987 (Monogenoidea: Diplectanidae), with the redescription of Acleotrema girellae Johnston & Tiegs, 1922

Acleotrema Johnston & Tiegs, 1922 is resurrected and its diagnosis amended. A. girellae Johnston & Tiegs, 1922 is redescribed based on the lectotype from the Australian Museum (Sydney, Australia). A. kyphosi Yamaguti, 1968 is considered a junior synonym of A. girellae. Heteroplectanum Rakotofiringa, Oliver & Lambert, 1987 is considered a junior synonym of Acleotrema. The nine species of the latter genus are transferred to Acleotrema as: A. diplobulbus (Yamaguti, 1968) n. comb., A. nenue (Yamaguti, 1968) n. comb., A. spiculare (Yamaguti, 1968) n. comb., A. yamagutii (Oliver, 1983) n. comb., A. nenuoides (Rakotofiringa, Oliver & Lambert, 1987) n. comb., A. parastromatei (Rakotofiringa, Oliver & Lambert, 1987) n. comb., A. serrulopenis (Rakotofiringa, Oliver & Lambert, 1987) n. comb., A. tamatavense (Rakotofiringa, Oliver & Lambert, 1987) n. comb. and A. oliveri (León-Règagnon, Pérez-Ponce de León & Garcia- Prieto, 1997) n. comb. An historical account of the species of Acleotrema is presented.     

The taxonomic status of <Emphasis Type="Italic">Opegaster</Emphasis> Ozaki, 1928 and the description of four new species of <Emphasis Type="Italic">Opecoelus</Emphasis> Ozaki, 1925 (Digenea: Opecoelidae) from marine teleosts in Australian waters

The similarities between Opecoelus Ozaki, 1925, Coitocaecum Nicoll, 1915, Opegaster Ozaki, 1928 and Paropecoelus Pritchard, 1966 and the difficulty of separating Opecoelus and Opegaster are discussed. It is proposed that Opegaster be reduced to synonymy with Opecoelus and the diagnosis of the latter amended to accommodate both forms. Four new species of Opecoelus are described from marine teleosts in Australian waters. These are Opecoelus woolcockae n. sp. from Acanthopagrus butcheri and A. australis from off South Australia, New South Wales and southern Queensland, O. pomatomi n. sp. from Pomatomus saltatrix off New South Wales, O. crowcrofti n. sp. from Atherinomorus ogilbyi off southern Queensland and O. queenslandicus n. sp. from Apogon fasciatus off southern Queensland. The following new combinations are formed: Opecoelus gonorhynchi (Gavrilyuk, 1979) n. comb., O. elongatus (Yamaguti, 1959) n. comb., O. pentadactylus (Manter, 1940) n. comb., O. apogonichthydis (Yamaguti, 1938) n. comb., O. cameroni (Caballero & Caballero, 1969) n. comb., O. dendrochiri (Yamaguti, 1970) n. comb., O. hawaiiensis (Yamaguti, 1970) n. comb., O. jamunicus (Srivastava, 1968) n. comb., O. longivesiculus (Yamaguti, 1952) n. comb., O. mastacembalii (Harshey, 1937) n. comb., O. mehrii (Harshey, 1937) n. comb., O. synodi (Manter, 1947) n. comb., O. tamori (Yamaguti, 1938) n. comb., O. bothi (Yamaguti, 1970) n. comb., O. caulopsettae (Manter, 1954) n. comb., O. beliyai (Pande, 1937) n. comb., O. brevifistulus (Ozaki, 1928) n. comb., O. cryptocentri (Yamaguti, 1958) n. comb., O. dactylopteri (Yamaguti, 1970) n. comb., O. dermatogenyos (Yamaguti, 1970) n. comb., O. ditrematis (Yamaguti, 1942) n. comb., O. gobii (Yamaguti, 1952) n. comb., O. hippocampi (Shen, 1982) n. comb., O. iniistii (Yamaguti, 1970) n. comb., O. lobulus (Wang, 1977) n. comb., O. macrorchis (Yamaguti, 1938) n. comb., O. parapristipomatis (Yamaguti, 1934) n. comb., O. pritchardae (Overstreet, 1969) n. comb., O. syngnathi (Yamaguti, 1934) n. comb., O. lutiani (Bravo-Hollis & Manter, 1957) n. comb., O. ovatus (Ozaki, 1928) n. comb., O. plotosi (Yamaguti, 1940) n. comb. and O. rectus (Ozaki, 1928) n. comb.; all the new combinations were previously species of Opegaster.     

Unification of the genera Nonlabens, Persicivirga, Sandarakinotalea and Stenothermobacter into a single emended genus, Nonlabens, and description of Nonlabens agnitus sp. nov

Phylogenetic analyses based on 16S rRNA gene sequences showed that a bacterial isolate, designated JC2678(T), represents a distinct phyletic line within the suprageneric monophyletic clade containing the genera Nonlabens, Persicivirga, Stenothermobacter and Sandarakinotalea. The polyphasic data presented in this study demonstrated that the members belonging to the Nonlabens-like clade overall constitute a single genus. Therefore, it is proposed to transfer the members of genera Persicivirga O'Sullivan et al. 2006, Stenothermobacter Lau et al. 2006 and Sandarakinotalea Khan et al. 2006 to the genus Nonlabens Lau et al. 2005. Thus, P. dokdonensis (Yoon et al. 2006) Nedashkovskaya et al. 2009, P. ulvanivorans Barbeyron et al. 2010, P. xylanidelens O'Sullivan et al. 2006, Sandarakinotalea sediminis Khan et al. 2006 and Stenothermobacter spongiae Lau et al. 2006 should be transferred to Nonlabens dokdonensis comb. nov., Nonlabens ulvanivorans comb. nov., Nonlabens xylanidelens comb. nov., Nonlabens sediminis comb. nov. and Nonlabens spongiae comb. nov., respectively. In addition, strain JC2678(T) (=KACC 14155(T)=JCM 17109(T)) is proposed to constitute a novel species belonging to the genus Nonlabens with the name of Nonlabens agnitus sp. nov.     

Ten new species of Haliotrema (Monogenoidea: Dactylogyridae) from Australian fish and a revision of the genus

Ten new species of Haliotrema from Australian fish are described and figured: H. cteno-chaeti sp. n. from Ctenochaetus strigosus; H. falcanalis sp. n. from Triacanthus falcanalis; H. lineate sp. n. from Acanthurus lineatus; H. chrysotaeniae sp. n. from Lutjanuschrysotaenia; H. cromileptis sp. n. from Cromileptis altivelis; H. epinepheli sp. n. from Epinephelus merra and E. fasciatus; H. holocentri sp. n. from Holocentrus ruber; Haliotrema chrysostomi sp. n. from Lethrinus chrysostomus and Plectorhinchus pictus; H. fleti sp. n. n. from L. fletus and L. chrysostomus; H. scari sp. N. from Scarus fasciatus.
H. dempsteri (Mizelle & Price, 1964) comb. n. from Acanthrus mata, A. dussumieri and A. xanthopterus: H. johnii (Tripathi, 1959) comb. n. from Lutjanus johni and L. fulviflamma: H. parahaliotrema (Mizelle & Price, 1964) comb. n. from Zebrasoma veliferum and A. grammoptilus: and H. obesa (Caballero, Bravo Hollis & Grocott, 1955) comb. n. from Tetraodon hispidus are redescribed and transferred from the genera Parahaliotrema Mizelle & Price, 1964, Ancyrocephalus Creplin, 1839, Parahaliotrema , and Tetrancistrum Goto & Kikuchi, 1917 respectively.
H. brevis (Mizelle & Price, 1964) comb, n. , H. canescens (Mizelle & Price, 1964) comb. n. and H. zanclus (Mizelle & Price, 1964) comb. n. are transferred from Pseudohaliotrema Yamaguti, 1953; H. eilatica (Paperna, 1965) comb. n. , H. teuthis (MacCallum, 1915) comb. n. , H. triacantha (Tripathi, 1959) comb. n. and H. lethrini (Yamaguti, 1937) comb. n. are transferred from Ancyrocephalus Creplin, 1839.
The generic diagnosis is emended to include the above-mentioned species and the taxonomy of the genus is discussed and the formation of six species groups is proposed.     

Description of a new cestode species Mircia shigini gen. et sp. n. (Cyclophyliidea: Schistotaeniidae)

A new genus and species of cestodes from the great-crested grebe Podiceps cristatus collected in the Eastern Europe is described. The genus Mircia gen. n. in addition to the type species M. shigini gen. n. includes the following species formerly being included in the genus Joyeuxilepis Spassky, 1947: M. decacantha (Fuhrmann, 1913) comb. n., M. decacanthoides (Borgarenko et Gulyaev, 1991) comb. n., M. fimbriata (Borgarenko, Spasskaja et Spassky, 1972), comb. n., and M. uralensis (Gulyaev, 1989) comb. n. Brief revision of the genus Joyeuxilepis is provide.     

Mathevotaenia niuguiniensis n. sp. (Cestoda: Anoplocephalidae: Linstowiinae) from the water-rat Parahydromys asper (Thomas) in Papua New Guinea, with a list of species of Mathevotaenia Akumyan, 1946

A new species of cestode, Mathevotaenia niuguiniensis n. sp. (Anoplocephalidae: Linstowiinae), is described from the hydromyine rodent Parahydromys asper (Thomas) in Papua New Guinea. This is the third species of the genus reported from the Australasian region. The new species differs from all congeners in rodents by having an elongate cirrus-sac, which crosses the osmoregulatory canals and extends into the medulla, compared with a short, ovoid cirrus-sac which does not penetrate into the medulla in congeners. It differs from the known Australian species, M. antechini (Beveridge, 1977) and M. nyctophili (Hickman, 1954), found in dasyurid marsupials and bats respectively, by lacking a complex of anastomosing osmoregulatory canals in each segment. A list of all known species of Mathevotaenia Akumyan, 1946, their host genera, host families and geographical distribution is provided. New combinations proposed in this report are: M. dipodomi (Bienek & Grundmann, 1973) n. comb. (transferred from Schizorchodes Bienek & Grundman, 1973), M. genettae (Ortlepp, 1937) n.comb., M. mephitis (Skinker, 1935) n. comb., M. pedunculata (Chandler, 1952) n. comb., M. wallacei (Chandler, 1952) n. comb. (transferred from Oschmarenia Spasskii, 1951) and M. oedipomidatis (Stunkard, 1965) n. comb. (transferred from Paratriotaenia Stunkard, 1965).     

A review of the Apocreadiidae Skrjabin, 1942 (Trematoda: Digenea) and description of Australian species

The Apocreadiidae is reviewed and is considered to include genera recognised previously within the families Apocreadiidae, Homalometridae, Schistorchiidae, Sphincterostomatidae and Trematobrienidae. Key features of the family are extensive vitelline follicles, eye-spot pigment dispersed in forebody, I-shaped excretory vesicle, no cirrus-sac and genital pore opening immediately anterior to the ventral sucker (usually) or immediately posterior to it (Postporus Manter, 1949). Three subfamilies and 18 genera are recognised within the Apocreadiidae. The Apocreadiinae comprises Homalometron Stafford, 1904 (new syn. Barbulostomum Ramsey, 1965), Callohelmis n. g., Choanodera Manter, 1940, Crassicutis Manter, 1936, Dactylotrema Bravo-Hollis & Manter, 1957, Marsupioacetabulum Yamaguti, 1952, Microcreadium Simer, 1929, Myzotus Manter, 1940, Neoapocreadium Siddiqi & Cable, 1960, Neomegasolena Siddiqi & Cable, 1960, Pancreadium Manter, 1954, Procaudotestis Szidat, 1954 and Trematobrien Dollfus, 1950. The Schistorchiinae comprises Schistorchis Lühe, 1906, Sphincterostoma Yamaguti, 1937, Sphincteristomum Oshmarin, Mamaev & Parukhin, 1961 and Megacreadium Nagaty, 1956. The Postporinae comprises only Postporus. A key to subfamilies and genera of the Apocreadiidae is provided. It is argued that there is no convincing basis for the recognition of the genus Apocreadium Manter, 1937 and all its constituent species are combined with Homalometron. The following new combinations are proposed for species previously recognised within Apocreadium: Homalometron balistis (Manter, 1947), H. caballeroi (Bravo-Hollis, 1953), H. cryptum (Overstreet, 1969), H. longisinosum (Manter, 1937), H. manteri (Overstreet, 1970), H. mexicanum (Manter, 1937) and H. vinodae (Ahmad, 1985). Apocreadium uroproctoferum Sogandares-Bernal, 1959 is found to lack a uroproct and is made a synonym of H. mexicanum. Homalometron verrunculi nom. nov. is proposed to replace the secondarily pre-occupied H. caballeroi Lamothe-Argumedo, 1965. Barbulostomum is made a synonym of Homalometron and H. cupuloris (Ramsey, 1965) n. comb. is proposed. Neochoanodera is made a synonym of Choanodera and Choanodera ghanensis (Fischthal & Thomas, 1970) n. comb. is proposed. Species within the Apocreadiinae and Postporinae are reviewed and the following are recorded or described from Australian fishes: Homalometron wrightae n. sp. from Achlyopa nigra (Macleay), H. synagris (Yamaguti, 1953) n. comb. from Scolopsis monogramma (Cuvier), H. stradbrokensis n. sp. from Gerres subfasciatus Cuvier, Marsupioacetabulum opallioderma n. sp. from G. subfasciatus, Neoapocreadium karwarensis (Hafeezullah, 1970) n. comb. from G. subfasciatus, N. splendens n. sp. from S. monogramma and Callohelmis pichelinae n. g., n. sp. from Hemigymnus melapterus (Bloch), H. fasciatus (Bloch), Stethojulis bandanensis (Bleeker) andChoerodon venustus (De Vis). Callohelmis is recognised by the combination of absence of tegumental spines, caeca terminating midway between the testes and posterior end of body, ventral sucker enclosed in a tegumental pouch, prominent muscles radiating through the body from the ventral sucker, vitelline follicles not extending into the forebody, and a very short excretory vesicle that opens ventrally. New combinations for species previously recognised within Crassicutis are proposed as follows: Neoapocreadium caranxi (Bilqees, 1976) n. comb., N. gerridis (Nahhas & Cable, 1964) n. comb., N. imtiazi (Ahmad, 1984) n. comb. and N. marina (Manter, 1947) n. comb. The host-specificity and zoogeography of the Apocreadiinae are considered.     

Lernanthropid copepods (Siphonostomatoida) parasitic on fishes of the Gulf of Thailand

Five species of copepods (Siphonostomatoida: Lernanthropidae) parasitic on fishes of the Gulf of Thailand are reported. They are: Lernanthropus corniger Yamaguti, 1954 from Megalaspis cordyla (Linnaeus); L. latis Yamaguti, 1954 from Lates calcarifer (Bloch); L. nemipteri Jayasree & Pillai, 1976 from Scolopsis lineata Quoy et Gaimard; L. sillaginis Pillai, 1963 from Priacanthus tayenus Richardson; and Norion tayenus n. sp. from P. tayenus. Except for L. sillaginis, the remaining four species are new to Thailand. Lernanthropus priacanthi Kirtisinghe, 1956 is transferred to Norion as N. priacanthi (Kirtisinghe, 1956) n. comb.     

Monogeneans from Pangasiidae (Siluriformes) in Southeast Asia: IV. Five new species of Thaparocleidus Jain, 1952 (Ancylodiscoididae) from Pangasius krempfi,P. kunyit,P. mekongensis and P. sabahensis

The examination of gill parasites from Pangasius krempfi Roberts & Vidthayanon, 1991; P. kunyit Pouyaud et al., 1999; P. mekongensis Gustiano et al., in press and P. sabahensis Gustiano et al., in press (Siluriformes, Pangasiidae) in Southeast Asia revealed the presence of six species of Monogenea, all belonging to the genus Thaparocleidus Jain, 1952 (Monogenea, Ancylodiscoididae) as defined by Lim (1996) and Lim et al. (2001). One has been previously described (T. vietnamensis Pariselle et al., 2002), five are considered as new species: T. humerus n. sp. and T. culter n. sp. on P. kunyit; T. mehurus n. sp. and T. culteroides n. sp. on P. sabahensis; and T. phuongi n. sp. on the four studied host species. The latter one, due to slight morphometric differences linked to geographical origin of hosts, is described as made up of three sub-species: T. phuongi phuongi n. sub-sp., T. phuongi malaysiensis n. sub-sp. and T. phuongi indonesiensis n. sub-sp.     

Two new genera,shape Provitellus and shape Ovipusillus,and four new species of Monorchiidae (Digenea) from carangid fishes of Queensland,Australia

Two new genera and four new species of monorchiid digeneans are described from the Great Barrier Reef and Moreton Bay, Queensland. Provitellus turrum n. g., n. sp. from Pseudocaranx dentex and Trachinotus coppingeri is characterised by the presence of vitelline follicles in the forebody, a single testis, a unipartite terminal organ and filamented eggs. Ovipusillus mayu n. g., n. sp. from Gnathanodon speciosus is characterised by the presence of two testes, vitelline follicles overlapping the ventral sucker and a large, complex cirrus-sac that contains a coiled eversible ejaculatory duct joined by the pars prostatica halfway along its length. Paramonorcheides pseudocaranxi n. sp. from Pseudocaranx dentex differs from other species described in this genus in the longer flatter forebody, entire ovary and the well-developed cirrus-sac. Chrisomon gaigai n. sp. from Trachinotus coppingeri and T. botla is characterised by the unflattened forebody and transversely oval pharynx. Chrisomon is redefined to include species of Lasiotocus with a vitellarium composed of clusters of tubular acini, creating the following new combinations: C. albulae n. comb. for L. albulae Overstreet, 1969, C. ulua n. comb. for L. ulua Yamaguti, 1970 and C. weke n. comb. for L. weke Yamaguti, 1970. The diagnosis of Lasiotocus is amended accordingly and the new combinations, L. polynemi n. comb. and L. sunderbanensis n. comb., are created for C. polynemi Dutta, Hafeezullah & Manna, 1994 and C. sunderbanensis Dutta, Hafeezullah & Manna, 1994, respectively. Extrapolation of our collection data suggests that there may be as many as 80 species of monorchiids infecting carangid fishes in Australia and 180 species infecting carangids in all oceans of the world. The latter figure greatly exceeds the number of monorchiids described from all host families to     

Two Lepotrema Ozaki, 1932 species (Digenea: Lepocreadiidae) from marine fishes from the southern Great Barrier Reef, Queensland, Australia

The genus Lepotrema Ozaki, 1932 is revived and redefined. Its main diagnostic characters are the dorsal excretory pore, the muscular development of the distal metraterm and the trilobate ovary. It is considered to contain five species, to which a key is given. Lepotrema clavatum Ozaki, 1932 is briefly redescribed from Amanses scopas and Sufflamen chrysopterus, and L. canthescheni n. sp. is described from Cantheschenia grandisquamis, based on material from the southern Great Barrier Reef. L. canthescheni is distinguished by its vitelline and uterine distribution. The other three recognised species are: L. adlardi (Bray, Cribb & Barker, 1993) n. comb., L. incisum (Hanson, 1955) n. comb. and L. xanthichthydis (Yamaguti, 1970) n. comb., all three having originally been placed in Lepocreadium.     

中国广东新海盘虫属(单殖吸虫,锚首虫科)三新种描述

记述了寄生于广东海洋鱼类五带豆娘鱼Abudefduf vaigiensis、六带豆娘鱼Abudefduf sexfasciatus和孟加拉豆娘鱼Abudefduf bengalensis鳃上的新海盘虫属Neohaliotrema Yamaguti,19653新种,瘤钩新海盘虫Neohaliotrema tukerhamatus sp.nov.,倒钩新海盘虫Neohaliotrema antiacanthus sp.nov.和孟加拉新海盘虫Neohaliotrema bengalensis sp.nov.3新种的中央大钩具有瘤状突起而相似于大棘新海盘虫Neohaliotrema macracanthum Zhukow,1976,但新种背中央大钩具有附片及腹中央大钩内突上有小钩与已知种不同,交接器尤其是支持器也存在较大的差异。瘤钩新海盘虫N.tukerhamatus sp.nov.的交接管末端有1锥状结构,支持器较长,前端为窄片状,末端分叉,腹中央大钩内突上有1小钩,背中央大钩具有1C形的附片;倒钩新海盘虫N.antiacanthus sp.nov.的支持器位于交接管中部弯曲处,呈倒钩形,腹中央大钩内突上有1小钩...     

Pauciconfibula subsolana n. sp. (Monogenea: Microcotylidae) from Morone americana (Perciformes: Percichthyidae) collected in fresh water in New Brunswick, Canada.

Pauciconfibula subsolana n. sp. (Monogenea: Microcotylidae) is proposed for parasites found on the inner surface of the operculum of Morone americana collected in the freshwater reaches of the Saint John River, near Mactaquac, New Brunswick. Pauciconfibula subsolana is differentiated from other species in the genus by the 2 posterolateral clamp sclerites, each of which is composed of 2 distinct sections, and by the absence of appendages on the eggs. An amended generic diagnosis is provided for Pauciconfibula. Pseudoaspinatrium Mamaev, 1986, is considered a junior synonym of Pauciconfibula Dillon and Hargis, 1965, and the species previously assigned to Pseudoaspinatrium are transferred to Pauciconfibula as Pauciconfibula euzeti (Ktari, 1971) n. comb., Pauciconfibula gallieni (Euzet and Ktari, 1971) n. comb., and Pauciconfibula pogoniae (MacCallum, 1913) n. comb.     

Diplectanum yamagutii sp.n.(Monogenea, Monopisthocotylea, Diplectanidae), Parasite de Kyphosus cinerascens (Forsskål) à Hawaii

Diplectanum yamagutii sp.n., a gill parasite of Kyphosus cinerascens (Forsskål, 1775) off Hawaii is described from amongst the type-material deposited by Professor S. Yamaguti in the National Parasite Collection of the United States National Museum of Natural History at Beltsville (Maryland, USA). Diplectanum yamagutii sp.n., D. diplobulbus Yamaguti, 1968, D. nenue Yamaguti, 1968, D. spiculare Yamaguti, 1968 and D. kyphosi (Yamaguti, 1968) comb.n. are sympatric parasites of Kyphosus cinerascens off Hawaii. These five species are distinguished by the shape and size of the armature of both the cirrus and the haptoral sclerotised pieces.     

Morphological descriptions of new and little-known benthic ciliates from Ganghwa tidal flat, Korea

Ciliates are highly diverse in the benthos where there are rare species to be unrevealed and described. By isolating species during successive and diversified cultivations, we discovered several new and interesting taxa from the top layer sediment of a muddy site in the Ganghwa tidal flat. These include three new species Spirodysteria ganghwaensis n. sp., Uronemella parafilificum n. sp., Zosterodasys minuta n. sp., and one poorly known form Loxophyllum chaetonotumBorror 1965. The morphology of live cells and infraciliature of these four species are described based on living observations, protargol impregnations, and morphometrics. Diagnoses and improved definitions are also provided. The newly established genus Spirodysteria n. g. differs from Dysteria mainly in its spirally twisted body shape. Spirodysteria kahli (Tucolesco 1962) n. comb. (formerly Dysteria kahliTucolesco 1962) has been included in this new genus.     

Description of two species of free-living nematodes (Nematoda) from fresh waterbodies of Vietnam

The new nematode species Monhystera longivaginata sp. n. and the rare species Mononchulus nodicaudatus (Daday, 1901) collected in waterbodies of Vietnam are described. M. longivaginata sp. n. is morphologically similar to M. paludicola de Man, 1881, but differs from it in a longer and slenderer tail in females, ocelli situated closer to the anterior end of the body, the presence of a postvulval gland cell, and a longer vagina. The genus Monhystera Bastian, 1865 is revised, and several species of this genus (M. lemani Juget, 1969, M. macramphus Filipjev, 1923, M. amabilis Gagarin, 1997, M. hamata Gagarin et Nguyen Vu Thanh, 2005, and M. melnikae Gagarin et Naumova, 2010) are transferred to the genus Eumonhystera Andrássy, 1981 as E. lemani (Juget, 1969) comb. nov., E. macramphus (Filipjev, 1929) comb. nov., E. amabilis (Gagarin, 1997) comb. nov., E. hamata (Gagarin et Nguyen Vu Thanh, 2005) comb. nov., and E. melnikae (Gagarin et Naumova, 2010) comb. nov.