Joaquín Abolafia

New proposal for a detailed description of the dorylaim spicule (Nematoda: Dorylaimida)

The morphology of dorylaimid spicules is richer than usually conceived and shows interesting interspecific variations that have not received much attention. New ideas are proposed to describe these structures, including a delimitation or definition of their parts and a series of morphometrics, either (absolute) measurements or ratios. Three descriptive examples are presented. Several morphological characters (head shape, development of the ventral hump, etc.) and a number of morphometric features (total and relative lengths, relative size of the median piece, terminal tip width, etc.) are especially useful for species characterisation and comparative purposes.

Two remarkable new species of the genus Crassolabium Yeates, 1967 from Vietnam (Nematoda: Dorylaimida: Qudsianematidae)

Two new species of the genus Crassolabium are described from natural areas in Vietnam. Crassolabium aenigmaticum sp. nov. is characterized by its body 1.23–1.58 mm long, lip region continuous, odontostyle 17.0–19.0 μm long, neck 320.0–397.0 μm long, uterus tripartite, pars refringens vaginae with two triangular pieces separated by an intermediate sclerotized area, V = 54–59, vulva longitudinal, tail short and rounded in both sexes, spicules 43.0–48.0 μm long, and seven to eight spaced ventromedian supplements. C. vietnamense sp. nov. can be distinguished in having body 1.55–1.88 mm long, lip region offset by constriction, odontostyle 19.5–22.0 μm long, neck 370.0–448.0 μm long, uterus very long and tripartite, pars refringens vaginae with two close together pieces, V =  55–59, vulva transverse and usually covered with a plug, tail short and rounded in both sexes, spicules 53.0–55.0 μm long, and eight to nine spaced ventromedian supplements, two of them within the range of spicules.

Nematodes of the order Rhabditida from Tehran province, Iran. The family Panagrolaimidae with description of Halicephalobus persicus sp. n. and a key to species of Halicephalobus Timm, 1956

Three species of the family Panagrolaimidae are described from mainly natural areas in Tehran province, Iran and a new species of the genus Halicephalobus is described and a key to species identification provided. Halicephalobus persicus sp. n. is characterised by a body length of 204-246 μm long in females, lateral field with two incisures, lip region with six flat, slightly separated, lips, pharynx with swollen bulb-shaped metacorpus, pharyngeal corpus 2.5-2.6 times isthmus length, female tail subcylindrical with fine mucro (40-53 μm; c = 4.4-5.2; c′ = 6.9-12.3). Iranian populations of three other previously known species were studied, viz. Propanagrolaimus hygrophilus, Panagrolaimus dendroctoni and P. rigidus, all being reported from Iran for the first time. The species are described, measured and figured.

On the identity of Chiloplacus magnus Rashid & Heyns, 1990 and C. insularis Orselli & Vinciguerra, 2002 (Rhabditida: Cephalobidae), two confusable species

Two very similar species of the genus Chiloplacus , namely C. magnus and C. insularis , are re-described and compared based on type material as well as Iberian specimens. Relevant new information is obtained for their characterisation and for elucidating their identity with more accuracy. Special mention is deserved by the findings regarding: i ) the morphology of the lateral field at vulval level; and ii ) the location of the vulva, which is either midventral or subventral, two remarkable traits that were originally overlooked. Chiloplacus magnus is distinguished by having the left lateral field expanded at vulval level and the vulva displaced to a subventral position, whereas C. insularis displays the usual pattern of the genus. The evolutionary relationships of the Iberian C. magnus are explored by means of D2-D3 sequence analysis. Chiloplacus similis is regarded as identical to C. magnus and is proposed as a new junior synonym of the latter.

Description of Panagrellus ulmi sp. n. (Rhabditida, Panagrolaimidae) from Iran, and comments on the species of the genus and its relatives

A new species of the genus Panagrellus, P. ulmi sp. n., has been found inside wetwood cankers of elms from the city of Tabriz, Iran. The new species is characterized by having small body size (0.91‒1.22 mm long in females and 0.82‒1.18 mm long in males), lateral field with three longitudinal incisures, lip region narrowing to distal end with six small lips and oral opening surrounded by six acute liplets, stoma with gymnostom shorter than cheilostom, cheilorhabdia not refringent, gymnorhabdia refringent, pharynx with metacorpus not swollen and isthmus slender, excretory pore at level of metacorpus, ovary very long without flexures, oviduct swollen, postvulval uterine sac long, 2.0‒3.4 times the corresponding body diameter, both female and male tails conoid-elongate, spicules with rounded and ventrally bent manubrium and lamina with dorsal anterior hump and fork-like bifurcate tip, gubernaculum with anterior dorsal handle-like manubrium, postcloacal genital papillae five pairs, two anterior subventral, one anterior subdorsal at same level than the first subventral, one posterior subventral and one posterior subdorsal both at same level. Description, measurements and illustrations are provided. In addition, species of Panagrellus and its relatives (Panagrobelus and Plectonchus) are analyzed. After this analysis, Plectonchus hunti is considered an intermediate species between Panagrellus and Panagrobelus, and is transferred, based on morphological and molecular evidence, to the latter genus as Panagrobelus hunti n. comb. On the other hand, Panagrellus (Panagrellinae) and Baujardia (Baujardinae), are two very similar genera according to both morphological and molecular evidence; we consider the respective subfamilies synonyms. Also, Plectonchus and Anguilluloides show great similarities, which justify considering Anguilluloides a junior synonym of the former genus. A. procerus is accordingly transferred as Plectonchus procerus n. comb. while Anguilluloides zondagi is considered a new junior synonym of Plectonchus molgos. Finally, emended diagnoses of the genera Panagrellus, Panagrobelus and Plectonchus, compendia, and keys to their species identification are included.

Redescription of Macrolaimus crucis Maupas, 1900 (Nematoda: Rhabditida: Chambersiellidae) from Spain, with scanning electron microscopy study and a compendium of the genus

Iberian material of Macrolaimus crucis, the type species of its genus, is described and illustrated based on light micropscope and scanning electron microscope observations. It is characterized by its body length, 654–863 μm in females and 654–767 μm in males; labial sensilla six conical setae forward directed; stoma nearly as long as wide (9–13 × 6–11 μm), with cheilostome slightly longer than gymnostome and cheilorhabdia and gymnorhabdia well developed; pharyngeal corpus 1.6–2.4 times isthmus length, with slightly swollen metacorpus; excretory pore located at isthmus level; female reproductive system prodelphic, lacking postvulval uterine sac; tail of both sexes conical (46–61 μm, c = 13.1–15.1, c′ = 3.1–4.0 in females, 38–48 μm, c = 14.6–17.2, c′ = 2.0–2.6 in males), ending in an acute and weakly bent dorsad tip, and phasmids at 60–70% of tail length; spicules 26–38 μm long; and gubernaculum 10–13 μm long. Iberian material is compared with type material and other known populations. The taxonomy of the genus is revised, including an emended diagnosis, an updated list of species, a key to their identification and a compendium of their morphometrics and diagnostic features.

Axonchoides smokyensis sp. n. (Dorylaimida: Belondiridae) from the Great Smoky Mountains National Park: the second species of a very rare genus

Axonchoides smokyensis sp. n., collected from a natural forest area in Tennessee, USA, is described and illustrated, including LM and SEM pictures as well as molecular (rRNA SSU-ITS1 and LSU D2/D3) sequences. The new species is characterised by its body length of 2.56-3.18 mm, lip region continuous and 10-12 μm wide, odontostyle 10-13 μm long, neck 662-789 μm long, anterior portion of pharynx enlarging gradually, pharyngeal expansion 407-548 μm long or 60-70% of the total neck length and surrounded by a strong muscular sheath with nearly longitudinal bands, female genital system pseudodidelphic-monodelphic with anterior branch lacking a functional ovary and posterior one bearing a long and tripartite uterus, V = 42-46, female tail slightly clavate (27-34 μm, c = 84-105, c′ = 0.8-1.0), male tail short and rounded (34-38 μm, c = 87-113, c′ = 0.7-0.9), spicules 49-53 μm long, and five or six widely spaced ventromedian supplements outside the range of the spicules. The taxonomy of Axonchoides is discussed on the base of morphological and molecular evidence, and an emended diagnosis proposed. It was easily differentiated from other sequenced dorylaimid taxa, but phylogenetic analysis from SSU and LSU failed satisfactorily to resolve its placement in Dorylaimina.

Nematodes of the order Rhabditida from Andalucía Oriental, Spain. The genus Chiloplacus Thorne, 1937, with description of C. maginensis sp. n. and a key to species

Five known and one new species of the genus Chiloplacus Thorne, 1937 are studied from natural ecosystems in the SE Iberian Peninsula: C.demani (Thorne, 1925) Thorne, 1937, C. maginensis sp. n., C. minimus (Thorne, 1925) Andrassy, 1959, C. magnus Rashid & Heyns, 1990, C. tenuis Rashid & Heyns, 1990 and C. trilineatus Steiner, 1940. Chiloplacus maginensis sp. n. is characterised by a female body length of 272-345 μm, lateral field starting far anterior near the labial region and with five incisures, lip region with bifurcate labial probolae bearing short prongs, pharyngeal corpus 2.5-3.6 times isthmus length, ovary without flexures posterior to vulva, spermatheca 8-17 μm long, postuterine sac 0.2-0.5 of corresponding body diam. long, female tail conical with rounded terminus (12-20 μm; c´ = 15.0-26.6; c′ = 1.1-1.5), phasmid at 39-48% of tail length. Descriptions, measurements and illustrations, including SEM photographs, are provided for the six species recorded. The diagnosis of Chiloplacus is emended, the nominal species listed and a key provided to those nominal species currently regarded as valid.

Especies de rhabdítidos (Nematoda, Rhabditida) citadas en España peninsular y las Islas Baleares

espanolSe presenta una recopilacion de citas previas de especies pertenecientes al orden Rhabditida en la Espana peninsular e Islas Baleares. Se listan ochenta especies de cuarenta generos y doce familias. La informacion que concierne a cada especie contiene el nombre cientifico, sinonimia, distribucion y observaciones. Los datos de distribucion incluyen las localidades y/o areas geograficas donde las especies han sido recolectadas, y las referencias correspondientes. Tambien se realiza una breve discusion sobre el conocimiento de los nematodos rhabditidos en el area iberica, concluyendose que la mayor parte de las especies se conocen deficientemente, siendo necesario un estudio taxonomico y/o faunistico adicional del taxon. EnglishPrevious records of species belonging to the order Rhabditida in peninsular Spain and Balearic Islands is presented as compilation. Eighty species of forty genera and twelve families are listed. Information concerning each species contains scientific name, synonymy, distribution and remarks. Distributional data include localities and/or geographical areas where the species have been collected and the corresponding references. A short discussion on current knowledge on rhabditid nematodes in the Iberian geography is also made. Majority of species are defficiently known, being necessary additional taxonomic and/or faunistic studies of this taxon.

On the identity of the genera Shahnema Siddiqi, 2014 and Baldwinema Atighi, Pourjam, Bert, Pedram, Ghaemi & Panahandeh, 2015, with proposal for their synonymy

Atighi et al. (2015) described the new genus Baldwinema, with three new species, namely B. ardabilense Atighi, Pourjam, Bert, Pedram, Ghaemi & Panahandeh, 2015, B. ilamense Atighi, Pourjam, Bert, Pedram, Ghaemi & Panahandeh, 2015 and B. golestanense Atighi, Pourjam, Bert, Pedram, Ghaemi & Panahandeh, 2015, all being recorded from Iran. Baldwinema Atighi, Pourjam, Bert, Pedram, Ghaemi & Panahandeh, 2015 was classified, based on molecular data, under Panagrolaimidae and characterised by having, among other features: i) lip region continuous with adjacent body and with amalgamated lips lacking probolae; ii) an aberrant stoma; iii) pharynx with valvular median bulb and non-valvate basal bulb; iv) monodelphic female reproductive system; v) tail long and filiform in both sexes, and vi) male without bursa; all in all, a characteristic and recognisable morphological pattern. It was compared with Aenigmenchus De Ley, Coomans & Geraert, 1994, both genera having in common several relevant morphological features, for instance valvate median bulb and non-valvate basal bulb, the former differing from the latter in its (p. 879) “tubular stoma lacking a stylet vs presence of stylet, and monodelphic-prodelphic reproductive system of female vs amphidelphic”. The position of Aenigmenchus was regarded as “still dubious” as it was originally assigned to Tylopharyngidae and later (Sudhaus & Fürst von Lieven, 2003) considered as incertae sedis.