Description of Metateratocephalus bialowieziensis sp. n. (Nematoda, Metateratocephalidae)

Описан новый вид Metateratocephalus bialowieziensis Holovachov, sp. n. из Польши, который отличается от других видов рода дорсально изогнутым телом, более длинным ректумом и комбинацией морфометрических признаков.A new species Metateratocephalus bialowieziensis Holovachov, sp. n. from Poland is described. It diffres from other species of the genus by dorsally arcuate body, linger rectum and by combination of morphometric characters

Morphology, phylogeny and evolution of the superfamily Plectoidea Örley, 1880 (Nematoda: Plectida

The phylogeny and classification of the superfamily Plectoidea Örley, 1880 is revised on the basis of published and updated morphological data for 35 ingroup and 2 outgroup species. The following features are here considered to support the monophyletic origin of the superfamily: 1) stegostom developed and differentiated into two sections; 2) dorsal gland orifice opening into the second stegostom section; 3) pharynx cylindrical, with distinct subdivision into corpus and postcorpus by the orifices of the subventral pharyngeal glands and a discontinuity in the muscular pharyngeal tissue; 4) corpus cylindrical, with subdivision into procorpus and metacorpus homologues; 5) pharyngeal radii of the corpus with prominent pharyngeal tubes along the procorpus; 6) cuticular lumen of the basal part of postcorpus (within basal bulb if latter is present) is modified to form a valvular apparatus. In addition the inner labial sensilla open inside the cheilostom. New data on postembryonic development of Anaplectus grandepapillatus (Ditlevsen, 1928), Plectus parietinus Bastian, 1865, P. decens Andrássy, 1985 and P. communis Bütschli, 1873 are given and supplemented with a discussion of the phylogenetic significance of the ontogeny in Plectoidea. Following the proposal of a phylogeny, some key events in the evolution of Plectidae Örley, 1880 are discussed. It is suggested that the superfamily Plectoidea includes four families: Pakiridae Inglis, 1983, Chronogastridae Gagarin, 1975, Metateratocephalidae Eroshenko, 1973 and Plectidae. Plectolaimus supplementatus Keppner, 1988 is transferred to the genus Caribplectus Andrássy, 1973. The genus Keralanema Siddiqi, 2003 is considered a junior synonim of Chronogaster Cobb, 1913. The genus Chiloplectus Andrássy, 1984 is considered a junior synonim of Plectus Bastian, 1865. The family Anaplectidae Zell, 1993 is downgraded to the subfamily leve

Morphology and Systematics of the Order Plectida Malakhov, 1982 (Nematoda)

Nematodes constitute one of the largest animal phyla. Hitherto about 20.000 species have been described but there are estimates that this number is less than 2% of the total number of existing species. Although the larger animal and human parasites were known since ancient times the description of free living nematodes and plant parasites started around 1850. Although nematodes can be found in almost every habitat, they are still one of the least known groups of extant metazoans. In a hierarchical organisation (classification) of nematodes, as for some other groups of multicellular animals, the higher the level, the greater the confusion and discrepancy among different opinions. It is clear, that the applied, prognostic and educational value of such artificial classification is low and requires further improvement.This thesis represents a small brick in the castle of humans' knowledge about nematode morphology, diversity and phylogeny. The author brings to light some new data and ideas about the form of some nematodes, how they develop and how they apparently evolved. Four main chapters deal with one of the smallest but morphologically and ecologically diverse orders, Plectida, whose members are found in marine, terrestrial and fresh water habitats.At the first stage of studies, just one genus, Anonchus, is analysed. Among the six known species included in the analysis, however, Anonchus shows considerable variability in morphology of reproductive organs, of both females and males. It is worth mentioning that morphological peculiarities of female gonads and the male copulatory apparatus are often used to separate populations into different species and to create higher taxonomic categories. The discovery of two new species, A. venezolanw and A. winiszewskae, adds even more to understanding the structural diversity of this genus. The analysis of the morphology of Anonchus species results in considerable rearrangement of the classification of this genus and its allies, which are placed in the newly reinstated family Aphanolaimidae.The main objective of the third chapter was to uncover the morphological diversity of representatives of mostly marine and presumably primitive groups of Plectida, and to propose a phylogenetic hypothesis of their relationships with each other and with their terrestrial allies (descendants ?). Additional descriptions are given for five species. Morphological and taxonomic analysis has been followed by the discovery of new taxa; the description of one, Paraplectonema loofi, is given in this chapter. Another, Procamacolaimus dorylaimus, is described in a separate article, but is also included in the phylogenetic reconstructions, which, on the whole, include 20 in-group laxa representing all distinct genera. A thorough systematic study required at least a brief discussion of phylogenetic affinities of the families Bastianiidae and Odontolaimidae and the genus Tobrilia which were previously included in the order Plectida. The taxonomic position of these taxa has become clearer in light of the new morphological data, particularly in the structure of male copulatory apparatus.The subsequent part of the thesis deals with the few species of the subfamily Wilsonematinae, whose members are one of the smallest terrestrial nematodes. The taxonomy of the Wilsonematinae has been severely hampered by the limits of light microscopy for correct observation and interpretation of their highly elaborate, complex labial region. The discrepancy between recent data and previous published descriptions of the structure of the labial region illustrates the great importance of scanning electron microscopy (SEM) for morphological and taxonomic studies of the group in question. Keeping this in mind, the author provides detailed redescriptions of five species of the genera Wisonema, Ereptonema and Neotylocephalus on the basis of both type and new material from diverse habitats and localities throughout the world. Reappraisal of the earlier morphological descriptions of these taxa resulted in substantial changes in their classification, and critical revision of all allied species and genera. Ultrastructural studies (SEM) made it possible to propose a phylogenetic hypothesis for the subfamily Wilsonematinae.The fifth chapter of this thesis includes a phylogenetic analysis of the largest terrestrial taxon of the order Plectida, superfamily Plectoidea. This analysis is based on published and updated morphological data for 35 in-group species. One of these species will be described as new in a separate publication. To better understand the character polarity, the postembryonic development of four species is described in detail. It was found that not only the general growth and development of reproductive system occurs during postembryonic development but that somatic sensilla, digestive and excretory systems also change morphologically during successive stages. Possible historical relationships of the superfamily Plectoidea are analysed using different methods and principles; one of the phylogenetic hypotheses was selected for thorough discussion, and as a basis for the revised classification of this taxon. Morphological data, which are elucidated and summarised in this chapter, provide the basis to further speculate on structural evidence for parthenogenetic reproduction in one of the studied genera, and the data also suggest several probable ways of niche partitioning in the superfamily Plectoidea.The general discussion summarises all taxonomic changes and suggestions proposed in preceding chapters, and gives a revised and updated classification of the order Plectida. Possible morphological adaptations to the fresh water habitat and structural changes associated with the soil habitat are briefly discussed based on the proposed phylogenetic hypothesis. Since family Plectidae sometimes has been suggested to be closely related to the scientifically and economically important order Rhabditida (=Secernentea), the author proposed that morphology of plectid genus, Anaplectus, may be a source for future research on the origin and evolution of rhabditids

Two new species of the genus Aphanolaimus (nematoda, aphanolaimidae) from cameroon

Описаны 2 новых вида рода Aphanolaimus de Man, 1880, характеризующихся следующими признаками: кутикулярная кольчатость гладкая, тонкоокругленные головные щетинки, слабо кутикулизированная стома, амфид без центрального утолщения, боковое поле зигзагообразное с двумя сублатеральными рядами точек, овальная ренетта; вагина прямая; самец не имеет шейных и преклоакальных щетинок, есть четыре хвостовые щетинки. У A. costatus Holovachov, sp. n. длина тела 358–477 мкм, 30–39 латеральных гиподемальных желез, первая соматическая пора расположена на 15–30-м кольце, боковое поле начинается на 1–4-м кольце; самец с пятью трубчатыми суплементами, спикулы 11–13 мкм в длину, с перекрученной головкой, угловатый рулек с хвостовым придатком. У A. camerunensis Holovachov, sp. n. длина тела 481–542 мкм, 10–13 латеральных гиподермальных желез, первая соматическая пора расположена на 28– 30-м кольце, боковое поле начинается на 3–5-м кольце; самец с тремя трубчатыми суплементами, спикулы 13–15,5 мкм в длину с овальной головкой, пластинкообразный рулек с хвостовым придатком.Two new species of Aphanolaimus de Man, 1880 are described, and both characterised by smooth cuticular annulation, finely rounded cephalic setae, weakly sclerotized stoma, amphid without central elevation, lateral field crenate with two sublateral rows of dots, renette cell oval; straight vagina; male without neck setae, without precloacal and with four caudal setae. A. costatus Holovachov, sp. n. has 358–477 mkm long body, 30–39 lateral epidermal glands, anteriormost body pore on 15– 30 annule, lateral field starting on 1st–4th annule; male with five tubular supplements, spicules 11–13 mkm long with twisted manubrium, rectangular gubernaculum with caudal apophysis. A. camerunensis Holovachov, sp. n. has 481–542 mkm long body, 10–13 lateral epidermal glands, anteriormost body pore on 28– 30 annule, lateral field starting on 3rd–5th annule; male with three tubular supplements, spicules 13–15.5 mkm long with elipsoid manubrium, platelike gubernaculum with caudal apophysis

Redescription of Anguinoides stylosum Chitwood, 1936 (Nematoda: Leptolaimidae)

Anguinoides stylosum Chitwood, 1936 is redescribed from type material. New data on the morphology of the species as well as emended diagnosis of the genus Anguinoides Chitwood, 1936 are given

Procamacolaimus Dorylaimus Sp. Nov. (Nematoda: Leptolaimidae) from the southern atlantic

Procamacolaimus dorylaimus sp. nov. is described from the Southern Atlantic (South Shetland Islands, Antarctica). The species is characterised by 3.4-3.5 mm long body; coarsely annulated cuticle without lateral field, epidermal glands and body pores absent, somatic setae present; labial sensilla papilliform, 5.5 mum long cephalic setae; amphid located anteriorly to cephalic setae bases; ocelli absent; deirid and secretory-excretory system absent; stoma 38-41 mum long, strongly cuticularised, spear-like; pharynx heavily muscularized, without radial tubules, valves and bulbs; male reproductive system diorchic; spicules 85.5 mum long, arcuate with ventrally inclined manubrium; gubernaculum complex; 12 tubular supplements, single precloacal setiform sensillum and two subventral postcloacal papilliform sensilla; female reproductive system didelphic, amphidelphic; spermatheca axial, vagina straight; tail conoid, ventrally arcuate; caudal glands present, spinneret small and weakly sclerotized. Procamacolaimus profundus Vitiello, 1974 is transferred to the genus Anguinoides whereas Paraphanolaimus granuliferus Timm, 1963 to Listia. The emended diagnosis, species lists and keys are given for Anguinoides, Procamacolaimus and Listia

Morphology, phylogeny and evolution of the superfamily Plectoidea Örley, 1880 (Nematoda: Plectida

The phylogeny and classification of the superfamily Plectoidea Örley, 1880 is revised on the basis of published and updated morphological data for 35 ingroup and 2 outgroup species. The following features are here considered to support the monophyletic origin of the superfamily: 1) stegostom developed and differentiated into two sections; 2) dorsal gland orifice opening into the second stegostom section; 3) pharynx cylindrical, with distinct subdivision into corpus and postcorpus by the orifices of the subventral pharyngeal glands and a discontinuity in the muscular pharyngeal tissue; 4) corpus cylindrical, with subdivision into procorpus and metacorpus homologues; 5) pharyngeal radii of the corpus with prominent pharyngeal tubes along the procorpus; 6) cuticular lumen of the basal part of postcorpus (within basal bulb if latter is present) is modified to form a valvular apparatus. In addition the inner labial sensilla open inside the cheilostom. New data on postembryonic development of Anaplectus grandepapillatus (Ditlevsen, 1928), Plectus parietinus Bastian, 1865, P. decens Andrássy, 1985 and P. communis Bütschli, 1873 are given and supplemented with a discussion of the phylogenetic significance of the ontogeny in Plectoidea. Following the proposal of a phylogeny, some key events in the evolution of Plectidae Örley, 1880 are discussed. It is suggested that the superfamily Plectoidea includes four families: Pakiridae Inglis, 1983, Chronogastridae Gagarin, 1975, Metateratocephalidae Eroshenko, 1973 and Plectidae. Plectolaimus supplementatus Keppner, 1988 is transferred to the genus Caribplectus Andrássy, 1973. The genus Keralanema Siddiqi, 2003 is considered a junior synonim of Chronogaster Cobb, 1913. The genus Chiloplectus Andrássy, 1984 is considered a junior synonim of Plectus Bastian, 1865. The family Anaplectidae Zell, 1993 is downgraded to the subfamily leve

Procamacolaimus Dorylaimus Sp. Nov. (Nematoda: Leptolaimidae) from the southern atlantic

Procamacolaimus dorylaimus sp. nov. is described from the Southern Atlantic (South Shetland Islands, Antarctica). The species is characterised by 3.4-3.5 mm long body; coarsely annulated cuticle without lateral field, epidermal glands and body pores absent, somatic setae present; labial sensilla papilliform, 5.5 mum long cephalic setae; amphid located anteriorly to cephalic setae bases; ocelli absent; deirid and secretory-excretory system absent; stoma 38-41 mum long, strongly cuticularised, spear-like; pharynx heavily muscularized, without radial tubules, valves and bulbs; male reproductive system diorchic; spicules 85.5 mum long, arcuate with ventrally inclined manubrium; gubernaculum complex; 12 tubular supplements, single precloacal setiform sensillum and two subventral postcloacal papilliform sensilla; female reproductive system didelphic, amphidelphic; spermatheca axial, vagina straight; tail conoid, ventrally arcuate; caudal glands present, spinneret small and weakly sclerotized. Procamacolaimus profundus Vitiello, 1974 is transferred to the genus Anguinoides whereas Paraphanolaimus granuliferus Timm, 1963 to Listia. The emended diagnosis, species lists and keys are given for Anguinoides, Procamacolaimus and Listia