An assessment of morphometric variability between populations of Longidorus vineacola Sturhan & Weischer, 1964 (Nematoda: Longidoridae) and morphologically related species

Morphometrics of female specimens from 46 populations and species belonging to the Longidorus vineacola Sturhan & Weischer, 1964 'complex' were examined. L. vineacola was present as 36 populations; L. attenuatus Hooper, 1961 and L. cohni Heyns, 1969 each as two populations; and L. apulus Lamberti & Bleve-Zacheo, 1977 , L. closelongatus Stoyanov, 1964 and L. pseudoelongatus Altherr, 1976 each as a single population. Specimens from two populations from France and Italy which had originally been identified as L. vineacola were found to be L. paraelongatus Altherr, 1974 and L. proximus Sturhan & Argo, 1983, respectively. A population from the Netherlands represented an unidentified species but the number of specimens available was insufficient to establish a new species. In a canonical variate analysis using the five morphometric characters of body, odontostyle, odontophore, anterior to guide ring and tail lengths, the L. vineacola populations formed several clusters and the other species formed separate clusters. All 46 populations formed a homogeneous group at 87% level of similarity. It is concluded that the five morphological characters used for the analysis provide a reliable means for distinguishing members of the L. vineacola complex of morphologically similar species. L. apuloides Roca, 1996 is considered a junior synonym of L. vineacola.     

Longidorus orongorongensis n. sp. (Nematoda: Dorylaimida) from subsoil of conifer/broadleaved forest

Abstract

Longidorus orongorongensis n. sp. is bisexual and recognisable from its large size (adults over 6 mm long), long odontostyle (145-172 μm), bluntly conoid lip region continuous with the body contour and especially by the posteriorly placed guide ring more than 60 μm from the oral aperture; also the female has a bluntly rounded tailless than an anal body width long. The first stage juvenile has a bluntly rounded tail. Juveniles and adults from one site below virgin forest are described.     

<Emphasis Type="Italic">Longidorus</Emphasis><Emphasis Type="Italic">kheirii</Emphasis> n. sp. (Nematoda: Longidoridae) from Iran

Longidorus kheirii n. sp., a parthenogenetic species, was found in soil samples collected from the rhizosphere of Rosa sp. growing in a natural mountainous region close to Maragheh city, northwestern Iran. It is characterised by having a long body (6.7-9 mm), a 19.5-23 mum wide head continuous with the body contour, a truncate and slightly concave lip region with convex sides between the anterior end and the guide-ring, an odontostyle 113-130 mum long, an odontophore 69-97.5 mum long, a body width of 90.5-117.5 mum at the mid-body, a long, wide oesophageal bulb (149.5-193.5 x 39.5-48 mum), a tail length of 47-72 mum, a male with 11 ventromedian supplements and spicules of 85 mum in length, and four juvenile stages. The ribosomal 18S rDNA gene of L. kheirii n. sp., L. leptocephalus Hooper, 1961, L. profundorum Hooper, 1966 L. euonymus Mali & Hooper, 1973 and two unidentified species listed as Longidorus sp. 1 and Longidorus sp. 2, all recovered from northwestern Iran in the same survey, and the ITS1 of L. kheirii n. sp. and Longidorus sp. 1 were sequenced in order to investigate the phylogenetic relationships with other previously sequenced Longidorus species.     

中国小无环咽属线虫一新纪录种(线虫纲,矛线目,无环咽科)

描述了采自山东省沂水县烟草Nicotiana tabacum Linn.根围土的中国线虫1新纪录种,钝尾小无环咽线虫Aporcelaimellus obtusicaudatus(Bastian,1865)Altherr,1968。该种主要的鉴别特征是雌虫虫体中等到大型,角质层由明显的2层组成;唇区角状,明显缢缩,唇瓣彼此分离;齿针强壮,长22.1(19.9～27.1)μm,其开口占齿针长的一半;食道矛线型,贲门圆锥形;雌虫双生殖腺,阴门通常位于体中部,内阴唇骨化明显,呈心形;内阴唇和阴道总长约占阴门处体宽的2/5;尾长31.9(23.2～37.3)μm,是肛门处体宽的0.7(0.6～0.8)倍,尾呈钝圆锥形到半球形,末端圆,有厚的肌肉层,肛门后有粗糙的放射状条纹。它与A.faridpuriensis的主要区别在于:齿针较短(19.9～27.1μm vs.35～39μm),前直肠较短(96.2μm vs.145μm)。它与A.krygeri的主要区别在于:齿针较短(22.1μm vs.25μm),尾较长(23.2～37.3μm vs.20～25μm),c’值大(0.6～0.8vs.0.2～0.3),尾呈钝圆锥形到半球形,A.krygeri尾非常短,半球形且背凹,具钉状末端(Singh,Sharma&Khatoon,2002;T horne,1974)。讨论了钝尾小无环咽线虫的已有报道和国内分布,对Aporcelaimellus属及相关属科的中文译名进行了厘订。     

Longidorus poessneckensis Altherr, 1974 and L. piceicola Lišková, Robbins & Brown, 1997 (Nematoda: Longidoridae): new records from Poland and the first description of the L. poessneckensis male and a bivulval female

Longidorus poessneckensis Altherr, 1974 and L. piceicola Lišková, Robbins & Brown, 1997 (Nematoda: Longidoridae) represent new records from Poland. These two species are described and illustrated together with a male and bivulval female of L. poessneckensis. In its general morphology and morphometrics, the male of L. poessneckensis is similar to the females, but has a spicule 100 μm long and one adanal pair, two double and a row of six single ventromedian supplements. Comments on the differential diagnosis of L. poessneckensis and two morphologically related species, L. uroshis Krnjaić, Lamberti, Krnjaić, Agostinelli & Radicci, 2000 and L. macrosoma Hooper, 1961 are given.     

Descriptions of Three New Longidorus Species from Alaska (Nematoda: Longidoridae)

Three new Longidorus species, L. alaskaensis n. sp., L. paralaskaensis n. sp., and L. bernardi n. sp., are described from specimens collected near Fairbanks, Alaska. Longidorus alaskaensis differs from all species of Longidorus by the presence of a caecum-like structure situated at the reflex of the oviduct. Longidorus paralaskaensis most closely resembles L. alaskaensis n. sp., L. crassus Thorne, L. picenus Roca, Lamberti &Agostinelli, and L. silvae Roca, differing from the last three of these species by having a parallel vs. a tapered lip region, and from all four by having a more narrowly rounded tail tip. Longidorus paralaskaensis differs from L. alaskaensis by having a longer odontostyle (119-128 vs. 110-118 μm) and by lacking the caecum-like structure found at the reflex of the oviduct. Longidorus bernardi n. sp. most closely resembles L. mirus Khan, Chawla &Seshadri, from which it differs by having a longer tail with a more acutely rounded tip, a longer body length (3.5-4.6 vs. 3.0-3.6 μm), and a larger c'' value (1.6-1.8 vs. 1.3-1.6). Longidorus bernardi differs from L. sylphus Thorne, L. africanus Merny, L. auratus Jacobs &Heyns, and L. conicaudatus Khan by having a slightly expanded lip region vs. a lip region with parallel body walls and a more finely rounded tail tip.     

Two new species of Longidoridae (Nematoda) from New Zealand forests

Xiphinema waimungui n. sp. from native forest in the North Island, New Zealand, is distinguished from many Xiphinema spp. by having two equal female genital branches, Z differentiation absent and tail short, convex-conoid. Females are 2.71–3.19 mm long, odontostyle 117–130 µm and odontophore 65–75 µm. Four juvenile stages are distinguished; tail shape does not vary markedly. Males were not found. Longidorus waikouaitii n. sp. from a native forest remnant in the South Island, New Zealand, has a rather posteriorly positioned guide-ring, large female body size (>6 mm), a bluntly conoid lip region which is continuous with the body contour and a bluntly rounded tail less than an anal body width long. No males and few juveniles were found. A dichotomous key is provided to the seven species of longidorids currently known from New Zealand.     

Morphological and Molecular Characterization of Longidorus americanum n. sp. (Nematoda: Longidoridae), a Needle Nematode Parasitizing Pine in Georgia

We describe and illustrate a new needle nematode, Longidorus americanum n. sp., associated with patches of severely stunted and chlorotic loblolly pine, (Pinus taeda L.) seedlings in seedbeds at the Flint River Nursery (Byromville, GA). It is characterized by having females with a body length of 5.4-9.0 mm; lip region slightly swollen, anteriorly flattened, giving the anterior end a truncate appearance; long odontostyle (124-165 µm); vulva at 44%-52% of body length; and tail conoid, bluntly rounded to almost hemispherical. Males are rare but present, and in general shorter than females. The new species is morphologically similar to L. biformis, L. paravineacola, L. saginus, and L. tarjani but differs from these species either by the body, odontostyle and total stylet length, or by head and tail shape. Sequence data from the D2-D3 region of the 28S rDNA distinguishes this new species from other Longidorus species. Phylogenetic relationships of Longidorus americanum n. sp. with other longidorids based on analysis of this DNA fragment are presented. Additional information regarding the distribution of this species within the region is required.     

Studies of the genus Enchodelus Thorne, 1939 (Nematoda, Nordiidae) from Arctic polar deserts. 1. Species with long odontostyle: E. makarovae sp. n. and E. groenlandicus (Ditlevsen, 1927) Thorne, 1939, with an identification key to the species of the E. macrodorus group

Two nematode species of the genus Enchodelus Thorne, 1939, one new and one known from Arctic polar deserts were studied. Enchodelus makarovaesp. n. is an amphimictic species, characterised by females with body length of 1.57-2.00 mm, lip region 15-17.5 μm wide, amphid duplex, odontostyle 38-43 μm long or 2.3-2.8 times lip region diam. Odontophore with flanges, 1.2-1.4 times as long as odontostyle; pharynx length 320-377 μm, pharyngeal expansion 113-130 μm long or 32-37% of total pharynx length; female genital system amphidelphic, uterus tripartite, pars refringens vaginae with two trapezoid sclerotisations, vulva a transverse slit (V=45-51%); tail bluntly conoid (25-35 μm, c=45.8-70.3, c'=0.6-0.9 in females, and 29-33 μm, c=46.4-58.9, c'=0.7-0.8 in males). Males with 65-74 μm long spicules and 10-12 spaced ventromedian supplements. Additional information for Enchodelus groenlandicus is provided, this being a new geographic record for the Putorana Plateau, Russian Arctic.     

New data on Longidorus aetnaeus Roca, Lamberti, Agostinelli & Vinciguerra, 1986 (Nematoda: Longidoridae) from Iran and Ajaria (Georgia)

Longidorus aetnaeus Roca, Lamberti, Agostinelli & Vinciguerra, 1986 is reported for the first time from Iran and Ajaria (Georgia). Morphological and morphometric data are provided for two Iranian and one Ajarian populations. The D2–D3 region of 28S rDNA for both Iranian populations was sequenced for the first time and the data reported. A detailed study of juveniles of L. aetnaeus from Iran, Georgia and Bulgaria demonstrated that this species develops through three juvenile stages. Furthermore, phylogenetic studies inferred from sequences for the D2–D3 region of 28S rRNA gene revealed that L. aetnaeus is most closely related to L. leptocephalus.     

Longidorus grandis n. sp. and L. paralongicaudatus n. sp. (Nematoda: Longidoridae), Two Parthenogenetic Species from Arkansas

Two new parthenogenetic species of Longidorus were found in Arkansas. Longidorus grandis n. sp. is characterized by its body (5.80-8.24 mm), slightly offset head, head width 20-27 µm, odontostyle 86-100 µm, guide ring 26-35 µm posterior to the anterior end, short conoid to mammiliform tail. Longidorus grandis n. sp. is similar to L. vineacola Sturhan &Weischer, 1964; L. lusitanicus Macara, 1985; L. edmundsi Hunt &Siddiqi, 1977; L. kuiperi Brinkman, Loof &Barbez, 1987; L. balticus Brzeski, Peneva &Brown, 2000; L. closelongatus Stoyanov, 1964; and L. seinhorsti Peneva, Loof &Brown, 1998. Longidorus paralongicaudatus n. sp. is characterized by its body length (2.60-5.00 µm), anteriorly flattened and offset head region 13-18 µm wide, odontostyle length 92-127 µm, guide ring 21-30 µm posterior to the anterior end, tail elongate-conical, and c'' = 1.2-2.6. Longidorus paralongicaudatus n. sp. most closely resembles L. longicaudatus Siddiqi, 1962; L. socialis Singh &Khan, 1996; L. juvenilis Dalmasso, 1969; and L. curvatus Khan, 1986.     

Longidorus ferrisi n. sp. from California Citrus

In October 1999, the authors received fixed specimens of a species of Longidorus from Howard Ferris found about the roots of a citrus tree in Oakville, Napa County, CA. After determining it to be new a species, we requested additional specimens. The samples contained roughly equal numbers of males and females. Longidorus ferrisi n. sp. is most similar to L. elongatus, but can be distinguished by a greater c-ratio (111-187 vs 73-141), a lesser c′ (0.7-1.1 vs 1.0-1.3), a more offset head, a more posterior guide ring (35-40 vs 30-33 μm), the presence of sperm in the uterus in mature females, and the approximate 1:1 ratio of females to males. Other similar species include L. artemisiae, L. crassus, L. glycines, and L. milanis. Longidorus ferrisi n. sp. differs from L. artemisiae by a lesser a-ratio (74-102 vs 109-155), a lesser c′ value (0.7-1.1 vs 1.0-1.6), a more posterior guide ring (35-40 vs 27-34 μm), a longer odontostyle (91-108 vs 84-98 μm), a wider lip region (16-19 vs 14-17 μm), wider mid-body (53-69 vs 41-52 μm), and longer spicules (57-65 vs 39-49 μm). The new species differs substantially from L. crassus by its lip shape and the presence of males, and differs from L. glycines by a shorter body (4.33-5.97 vs 6.14-8.31 mm), a lesser c′ value (0.7-1.1 vs 0.9-1.4), a narrower lip region (16-19 vs 20-23 μm), wider mid-body (53-69 vs 39-57 μm), longer spicules (53-69 vs 45-53 μm), and fewer supplements (7-11 vs 11-17). Longidorus ferrisi n. sp. differs from L. milanis by a longer body (4.33-5.97vs 3.00-4.90 mm), a greater c value (111-187 vs 86-130), a wider mid-body (53-69 vs 43-56 μm), a different head shape, and longer spicules (53-69 vs 41-54 μm). The nuclear 18S ribosomal DNA sequence of this species revealed that this species is unique with respect to all sequenced Longidorus species.     

Longidorus paravineacola n. sp. (Nematoda: Longidoridae), a New Species from Arkansas

Longidorus paravineacola n. sp., described herein, was found in a survey of longidorids of Arkansas. It is a parthenogeneticspecies characterized by its long body (6.68-9.85 mm); slightly expanded and rounded head, head width 21-27 µm; odontostyle length 95-114 µm; guide ring 28-37 µm posterior to the head end; short rounded tail, and c'' = 0.6-1.0. Longidorus paravineacola n. sp. is similar to the amphimictic species L. vineacola Sturhan &Weischer, 1964; L. balticus Brzeski, Peneva &Brown, 2000; L. kuiperi Brinkman, Loof &Barbez, 1987; and parthenogenetic species L. crassus Thorne, 1974, which also occurred in the type locality.     

Longidorus biformis n. sp. and L. glycines n. sp. (Nematoda: Longidoridae): Two Amphimictic Species from Arkansas

Two new amphimictic species of Longidorus were found in Arkansas. Longidorus biformis n. sp., found in the rhizosphere of hardwood trees along streams in sandy soil in 14 Arkansas locations, is characterized by its long body (5.42-9.50 mm), wide expanded flattened head end, head width 20.0 to 26.0 µm, odontostyle 96 to 125 µm, guide ring 29 to 38 µm posterior to the anterior end, elongate conoid tail, and c'' = 0.9-2.1. Females with 2 to 11 vetromedian supplement-like structures were found in 2 of 14 populations of this new species. Longidorus biformis n. sp. is closest to L. seinhorsti Peneva, Loof &Brown, 1998 and L. closelongatus Stoyanov, 1964. Among North American species it is closest to L. glycines n. sp. A distinguishing feature of L. biformis n. sp. is the presence of supplement-like organs in some females. Longidorus glycines n. sp., found in soybean microplots at the Main Research Station, Fayetteville, Arkansas, is characterized by its long body (6.14-8.31 mm), wide offset flattened head end, head width 20.3 to 23.3 µm, odontostyle 87.3 to 99.5 µm, guide ring 22.3 to 26.4 µm posterior to the anterior end, short conoid tail with rounded terminus, and c'' = 0.9-1.4. Longidorus glycines n. sp. is closest to L. lusitanicus Macara, 1985. Among North American species it is close to L. biformis n. sp., L. breviannulatus Norton and Hoffman, 1975, and L. crassus Thorne, 1964. Both new species are believed to have four juvenile stages; the first stage was not found for L. biformis n. sp.     

Description of Dorylaimoides punctatus n. sp. and Paractinolaimus acutus n. sp. (Nematoda: Dorylaimida) from Korea

Soil samples collected from Taebak Changkunbong and Undal mountains of Kyungbuk Province, yielded two new species of the order Dorylaimida which are described and illustrated below. Dorylaimoides punctatus n. sp. (Nematoda: Dorylaimida) is 1.2–1.4 mm long; b = 5.9–6.9; c = 14.6–17.7; odontostyle 7.3–8.5 μm; spicules 33.5–36.5 μm; ventromedian supplements 5–6 and is characterized by having zig-zag lines on body cuticle, continuous lip region, elongate conoid tail and comes close to Dorylaimoides micoletzkyi (De Man, 1921) Thorne & Swanger, 1936 and Dorylaimoides leptus Husain & Khan, 1968. Paractinolaimus acutus n. sp. (Nematoda: Dorylaimida) is 2.1–2.4 mm long; b = 4.3–4.9; c = 10–12; odontostyle 25–27 μm and characterized by having continuous lip region, longitudinally oval vulva and long filiform tail with acute tip and comes close to Parctinolaimus aruprus Khan et al., 1994 and Parctinolaimus baldus Thorne, 1967.     

Paralongidorus bullatus n. sp. from Groundnut Soils in Niger and Comments on Xiphinema parasetariae Luc

Paralongidorus bullatus n. sp. from groundnut soils in Sador''é Niger is described and illustrated. It is distinguishable from most species of the genus by its body and odontostyle lengths, knob-like head, and digitate ending of the protoplasmic region of the tail. Length of the female body is 4.4-5.5 mm, of the odontostyle 132-156 μm, and of the tail 32-44 μm. Tail terminus is conoid to broadly rounded. Uteri are well developed, without sperms. Males are not found. Xiphinema parasetariae Luc 1958, a species inquirenda, is validated and, based on measurements and tail structures, X. attorodorum Luc 1961 is proposed as a synonym of X. parasetariae. Additional measurements are given for its females and juveniles.     

Descriptions of Three New Longidorus Species from Slovakia (Nemata: Longidoridae)

Three new Longidorus species from Slovakia are described. Longidorus carpathicus n. sp. most closely resembles Longidorus silvae but differs by having a longer odontostyle, odontophore, and total stylet; smaller a and c ratios; and longer distance to the guide ring. This new species also resembles L. picenus, L. macrosoma, and L. major but differs by having a narrower lip width. It further differs from L. picenus by having a longer odontostyle and smaller c ratio, and by lacking males; from L. macrosoma by having a longer odontostyle, smaller c ratio, by lacking males, and a more pronounced J1 tail peg; and from L. major by having a shorter body length, longer odontostyle, longer odontophore, and longer J1 tail peg. Longidorus piceicola n. sp. most closely resembles L. eridanicus, from which it differs by having a greater lip width, longer tail, smaller c ratio, larger c'' ratio, shorter hyaline tail length, and a conically rounded vs. hemispherical tail. This new species differs from L. cylindricaudatus by having a larger lip width, longer odontostyle and odontophore, and a greater distance to the guide ring; from L. nevesi by having a shorter body length, longer odontostyle, larger c'' ratio, and shorter hyaline tail length. Longidorus juglansicola n. sp. most closely resembles L. athesinus but differs by its longer body, wider lips, and larger a and c ratios. It closely resembles L. vineacola but differs by its shorter body length, smaller c ratio, and an almost parallel lip outline vs. an expanded lip outline; from L. lusitanicus by a longer odontophore and tail, and an almost parallel lip outline vs. an expanded lip outline.     

A new species of the genusEudorylaimus Andrássy, 1959 (Nematoda: Qudsianematidae) from East Antarctica

 Eudorylaimus shirasei sp. nov. is described as the seventh member of the genus in the Antarctic region. The specimens were found among green algae collected near the Molodezhnaya Station of Russia, and in moss from Cape Ryugu on the Prince Olav Coast, East Antarctica. This species resembles E. similis (de Man, 1876), E. coniceps Loof, 1975 and E. imitatoris Gagarin, 1982, but differs from them in the shape of the tail and some other characteristics on the lip region, odontostyle, spicules and precloacal supplements. It is also similar to three species known from females, E. eremitus (Thorne, 1939), E. jurassicus (Altherr, 1953) and E. altherri Tjepkema et al., 1971, but differs in the features of the body length, lip region, amphids, odontostyle and vulva. The present species has multinucleate intestinal cells, which have not been so far reported in Eudorylaimus. It is possible that the multinucleation of intestinal cells has been overlooked in the previously known species of the genus. Received: 11 April 1995/Accepted: 19 June 1995