New species of Rhabdochona Railliet, 1916 (Nemata: Rhabdochonidae) from Rainbow Trout in California Streams

Three new species of Rhabdochona Railliet, 1916 are described and illustrated from Salmo gairdneri Richardson (rainbow trout) in freshwater streams in California: Rhabdochona californiemis n. sp., R. paxmani n. sp., and R. satmonis n. sp. Rhabdochona californiensis n. sp. is characterized by 14 anteriorly directed teeth in the prostome, egg devoid of filaments or floats, male and female tail terminus with a single mucro, left (long) spicule slender with a moderate distended podoid terminal end, spicular ratio 1:3.8. Rhabdochona paxmani n. sp. is characterized by 10 teeth in the prostome, eggs with polar floats, left (long) spicule slender with podoid terminus distended and having a minute subterminal spine; right spicule with prominent gorgeret (barb), spicular ratio 1:4.3, male and female tail terminus with a cuticular conical rounded short projection. Rhabdochona salmoni, n. sp. is characterized by 10 teeth anteriorly directed in the prostome, eggs with polar floats, left spicule slender with a distended podoid terminus; right spicule with a sharply indented gorgeret, spicular ratio 1:4.3, male and female tail terminus with a conical or rounded tip.     

Descriptions of Four New Species of Criconematoidea (Tylenchina: Nemata) from Southern Chile

Four new species of Criconematoidea are described from Hoste Island, Chile. Criconema certesi n. sp. is distinguished by the fine, spine-like, cuticular extensions on body annuli; projection of annuli into rows of scales on posterior part of body; single, smooth, labial annulus set off by short collar from second (first body) annulus which is about same diameter as first (labial) annulus. Male with prominent caudal alae, slender curved spicules, and four incisures in lateral field. Ogma terrestris n. sp. is distinguished by small scales with rounded tips bearing minute, short bristles; scales number 21 at mid-body; and first (labial) annulus rounded, not retrorse, not set off from succeeding annuli, narrower in diameter from second (first body) annulus. Hemicycliophora macrodorata n. sp. is distinguished by its large size (L = 1.52 [1.28-1.72] mm); large stylet (146 [127-161] μm); annuli = 297 (280-315); tail slightly spicate, lateral field with or without interruptions of incisures, occasional anastomoses; and males with U-shaped spicules. Paratylenchus fueguensis n. sp. is distinguished by its prominent stylet with large, rounded knobs (4-5 μm across); cephalic region rounded not at all set off; lateral field with four incisures; lateral vulvar membranes present; and male tail short, strongly curved (almost 180°) ventrad.     

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.     

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.     

Description of Pratylenchoides camachoi n. sp. (Tylenchida: Pratylenchidae) from Spain

Pratylenchoides camachoi n. sp. from rosemary (Rosmarinus officinalis L.) in Sierra De Cazorla in southeastern Spain is described and illustrated. Pratylenchoides camachoi n. sp. is a bisexual species characterized by a cylindroid, sometimes clavate-shaped, male tail with a uniquely shaped smooth, rounded terminus. Females are characterized by a short esophageal overlap and six lines in the lateral field, which reduce to four in the tail region; not areolated except outer bands in the esophageal and tail regions.     

Taxonomic and Molecular Identification of Bakernema,Criconema, Hemicriconemoides,Ogma and Xenocriconemella Species (Nematoda: Criconematidae)

Populations of Bakernema inaequale, C. petasum, C. sphagni, C. mutabile, Ogma octangulare, Xenocriconemella macrodora and Hemicriconemoides chitwoodi were identified and re-described from different geographical areas in the continental United States and molecularly characterized. Two new species of spine nematodes Criconema arkaense n. sp. from Washington County and Lee County, Arkansas and Criconema warrenense n. sp from Warren, Bradley County, Arkansas are also described and named. Criconema arkaense is characterize by having a conspicuous lip region offset from the body with two annuli, short rounded tail with a thin cuticular sheath and subterminal anus. Criconema warrenense n. sp. has two lip region annuli about the same width, first annulus directed posteriorly, separated by a narrow neck annulus and a short conoid tail, unilobed non-folded annulus. The molecular characterization of Criconema arkaense and Criconema warrenense using ITS1 rDNA gene sequence and the molecular phylogenetic relationships of these new species along with the known spines nematodes are provided.     

Aporocotyle mariachristinae n. sp., and A. ymakara Villalba & Fernández, 1986 (Digenea: Aporocotylidae) of the pink cusk-eel,Genypterus blacodes (Ophidiiformes: Ophidiidae) from Patagonia,Argentina

Aporocotyle mariachristinae n. sp. and A. ymakara Villalba & Fernández, 1986 were collected from the bulbus arteriosus and ventral aorta of pink cusk-eels, Genypterus blacodes (Forster, 1801) from Patagonia, Argentina. A. mariachristinae n. sp. can be distinguished from all the species of Aporocotyle by the asymmetrical extension of posterior caeca (right posterior caecum longer, terminating at the area between mid-level of ovary and posterior body end; left posterior caecum shorter, terminating at the area between mid-level of cirrus sac and posterior to reproductive organs), the distribution of spines along the ventro-lateral body margins and the number of testes. The new species clearly differs from A. ymakara, from the same host species, in the esophagus / body length ratio, the absence of distal loops at caeca, the anterior caeca / posterior caeca length ratio, and the number of testes. Additionally, in A. ymakara the left posterior caecum may be longer than right posterior caecum, while in the new species left posterior caecum is always shorter. The specimen of A. ymakara collected from Argentina is also described. We also provide observations of the distribution of spines in different species of Aporocotyle, including new specimens of A. argentinensis Smith, 1969 from Merluccius hubbsi Marini, 1933. Molecular sequence data obtained from partial 18S and 28S rDNA regions were compared between the new species and other two species of Aporocotyle (A. argentinensis and A. spinosicanalis Williams, 1958). This is a new locality record for A. ymakara, extending the known geographical distribution for this species from Chile to Argentina, and the first report of two species of Aporocotyle in the same host species and locality.     

Marine Nematodes of Bothnian Bay,Finland: Ethmolaimus hailuotoensis n. sp. (Ethmolaimidae: Nemata)

Ethmolaimus hailuotoensis n. sp. from Bothnian Bay, northern Baltic Sea, is described and illustrated. Ethmolaimus hailuotoensis n. sp. has a strongly sclerotized luminal lining of the terminal esophageal bulb and esophagus. The most characteristic feature is a lateral series of large concentric, sclerotized rings with a fine, internal longitudinal oval sclerotization. In addition, E. hailuotoensis n. sp. is distinguished from other Ethmolaimus species by its smaller body size, fewer number of precloacal supplements (7-8), conical tail, and the position of amphid posterior to the buccal cavity. Females of E. hailuotoensis n. sp. studied were hermaphroditic. Ethmolaimus hailuotoensis n. sp. coexisted with E. pratensis. Ethmolaimus pratensis from Bothnian Bay has a characteristic row of sublateral hypodermal glands, a character not before seen in Ethmolaimidae.     

A new species of Dicranocentrus (Collembola,Entomobryidae) from China with comments on the systematic position of the genus

Dicranocentrus liuae sp. n. is described from the northern subtropical region of China. The new species is most similar to D. wangi Ma & Chen, 2007, but differs from it in the relatively shorter Ant. V, the 1+1 central macrochaetae on Abd. III, the number of chaetae on tenaculum, and the absence of dental spines. The systematic position of Dicranocentrus is also discussed. Present evidence, particularly S-chaetotaxy, indicates that the genus is closer to Heteromurus than to the unscaled species of Orchesella and Orchesellides.     

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.     

Thalassomermis megamphis n. gen., n. sp. (Mermithidae: Nemata) from the Bathyal South Atlantic Ocean

Thalassomermis megamphis n. gen., n. sp. (Mermithidae: Nemata) was extracted from sediment collected off the coast of Brazil at a depth of approximately 1,000 m. Although the food of this new nematode is unknown, the reduction of the stoma and esophagus and presence of a trophosome indicate that it is parasitic in its juvenile stages. Thalassomermis megaraphis n. gen., n. sp. is assigned to Mermithidae because of its similarity to that family in the appearance of the cephalic sensory receptors, the long and tubular vagina, and copulatory muscles of the male extending posteriorly throughout most of the length of the tail. Thalassomermis megamphis n. gen., n. sp. differs from all other members of Mermithidae by the large, lenticular, intracuticular amphidial fovea with coiled, emergent terminal filaments as well as the small amphidial aperture situated over the center of the fovea.     

Three New Species of Nothacrobeles (Nemata: Cephalobidae) from the Mojave Desert, California

Three new species of Nothacrobeles are described from localities in the Mojave Desert, southern California. Nothacrobeles triniglarus n. sp. is characterized by the presence of a long post-vulval sac and three tubular adoral projections. Both N. spatulatus n. sp. and N. nanocorpus n. sp. are smaller than any other known species within the genus. Nothacrobeles spatulatus n. sp. has labial probolae that are short and spatulate without a basal ridge, whereas those of N. nanocorpus n. sp. are flattened and plate-like. Furthermore, N. nanocorpus n. sp. is unique by its extremely short esophageal corpus (less than 25 µm long in adult females) and the small size of its guard processes. An emended diagnosis of the genus is given to accommodate distinctive characteristics of these new species. A table comparing the 11 valid species of Nothacrobeles is presented.     

Nematodes of the Order Rhabditida from Andalucía Oriental,Spain. The Genera Nothacrobeles Allen &Noffsinger, 1971 and Zeldia Thorne, 1937

A new species of the genus Nothacrobeles is described from natural areas (a salt lake) in the Southeast Iberian Peninsula. Nothacrobeles lanceolatus sp. n. is characterized by its body length, two rows of cuticular punctations per annulus, labial probolae bifurcate with divergent prongs, pharyngeal corpus 2.4 to 3.5 times isthmus length, spermatheca length, postuterine sac 0.5 to 1.1 times the corresponding body diameter ratio, female tail conical and bearing a spindle-shaped or conical mucro with acute terminus, phasmid at 8 to 17 µm posterior to the anus, male tail conical with acute mucro, spicules length, and gubernaculum length. In addition, Nothacrobeles cf. lunensis and Zeldia punctata are studied. Cervidellus capricornis is transferred to genus Nothacrobeles. A key to species of Nothacrobeles is also provided.     

Two New Species of Aphelenchoididae (Nemata) from Declining Red Pines in Maryland

Aphelenchoides resinosi n. sp. and Ektaphelenchus joyceae n. sp. are described and illustrated from red pines of the Allegheny plateau of Maryland, USA. The new species were found in trees infested with Bursaphelenchus xylophilus. Primary diagnostic characters of A. resinosi females are constriction of the head, basal stylet knobs, tong postuterine sac, two incisures in the lateral field, and conical tail four to five anal body widths long with a simple terminal mucro. Diagnostic characters of the males are two pairs of subventral caudal papillae and spicule shape: Primary diagnostic characters of E. joyceae females are a slight constriction of the head, six similar lips, conical tail, and short postuterine sac. Diagnostic characters of the males are spicule size and shape, a single row of spermatocytes, and one pair of caudal papillae. Within-tree distributions of A. resinosi and E. joyceae are presented. A total of 70% of both red-needled and chlorotic-needled trees in the study were positive for A. resinosi and E. joyceae. Branch hierarchy was related to the percentage of samples positive for A. resinosi.     

Heterorhabditidoides rugaoensis n. sp. (Rhabditida: Rhabditidae), a Novel Highly Pathogenic Entomopathogenic Nematode Member of Rhabditidae

A novel entomopathogenic nematode species, Heterorhabditidoides rugaoensis n. sp. RG081015, collected from Rugao, China, is described. The new species is morphologically very similar to H. chongmingensis but can be distinguished from it on the basis of some morphological characteristics, combined with molecular data and a cross-hybridization test. Males of the new species can be recognized on the basis of body length averaging 1396.2 μm; lateral field with one ridge; metastome isoglottoid with one hemispherical swellings comprised of two to three well-developed warts; asymmetric spicules; peloderan bursa. In IJs, EP = 134.5 μm; ES = 149.3 μm; tail length = 82.5 μm; and a = 20.5. Hermaphroditic females have four to five lateral ridges. The 18S rDNA and ITS sequences of the two nematodes share 99% and 98% identity, respectively. Phylogenetic trees of 18S rDNA and ITS indicate that the new species is most closely related to H. chongmingensis; thus, the two nematodes belong to the same genus. Failure of cross-hybridization between them indicates that nematode strain RG081015 is a novel species and is described herein as H. rugaoensis n. sp. The LC₅₀ of the novel species against Galleria mellonella were 24.35 IJs / ml within 48 hours of infection. Morphological characteristics, genetic similarity analyses, and phylogenetic relationships provide strong evidence that some species of Oscheius/Insectivora-group should be reassigned to the genus Heterorhabditidoides.