Displaying all 2 publications

Abstract:
Sort:
  1. Gerasev PI
    Parazitologia, 2009 Nov-Dec;43(6):478-501.
    PMID: 20198967
    Systematization and description of composition and structure of the monogeneans from the genus Dactylogyrus Diesing, 1850 mostly having five rayed ventral (additional) bar of the haptor and parasitizing mainly Palaearctic Barbinae and Leuciscinae, were carried out. These dactylogyrids have Palaearctic origin and occur in the north-western Africa, central and southern Europe, Transcaucasia, middle Asia, Mesopotamia and also in India and the Malacca Peninsula. Previously the analysis of dactylogyrids' distribution by continents (Gerasev et al., 1996), geographical regions (Gerasev, Timofeeva, 1997), taxonomic groups of hosts (Gerasev, 2008a, 6), and different taxonomic groups of host inside one geographical division (Kolpakov et al., 2007; Gerasev et al., 2007, 2008) was performed. This analysis have not been always resulted in the understanding of conjugate evolution of these parasites and their fish hosts, as well as in the resolving of problems concerned with speciation of monogeneans and phylogeography of their hosts. Therefore, in present work we consider more than one geographical region, different fish taxa, and the morphological groups of worms reflecting morphological variational series of types of copulatory organ and additional bar. Typification of copulatory organ, additional bar, anchors, and type of seating for 11 Palaearctic morphological groups of dactylogyrids mainly having five rayed additional ventral bar, were carried out. Four morphological groups of dactylogyrids of African, Indian, and different Palaearctic origin also parasitizing Palaearctic barbs were additionally included into analysis. In all, 92 species of dctylogyrids from 78 host species were considered. Analysis of speciation and phylogeny of dactylogyrids having five rayed additional ventral bar of haptor; conjugate evolution of these dactylogyrids and their fish hosts (mainly Barbinae); point of origin of Palaearctic polyploids Barbinae, and expansion of these fishes over the territory of Palaearctic will be discussed in next article.
  2. Ryss AIu
    Parazitologia, 2007 Mar-Jun;41(3):161-94.
    PMID: 17722638
    The amended diagnosis of the genus Pratylenchoides and list of its valid species with synonyms are given. All the efficient diagnostic characters are listed. Modern taxonomic standard for the description of Pratylenchoides species is proposed; it may be used also in taxonomic databases. Tabular and text keys for all species of the genus are given. Five following groups are considered within the genus Pratylenchoides. The group arenicola differs from other groups in the primitive adanal bursa type; the groups magnicauda, crenicauda, ritteri, and megalobatus differ from each other in the position of cardium along the body axis in relation to the pharyngeal gland nuclei, pharynx types are named according to the stages of its evolution from the primitive tylenchoid pharynx (cardium situated posteriorly) to the advanced hoplolaimoid one (cardium situated anteriorly). Diagnoses and species compositions of the groups are given. Basing on the matrix of species characters, the dendrogram has been generated for all species of Pratylenchoides and for all characters (UPGMA, distance, mean character difference, random, characters ordered). Taking in view that the PAUP software gives equal weights to all characters, including the most important ones which define the prognostic species groups, the separate dendrograms for each prognostic species group were generated using the same above mentioned tree parameters. On the base of the records of Pratylenchoides species the matrices of plant host ranges, geographic distribution, and preferred soil-climatic conditions were developed. The dendrograms of the faunal similarities were generated using these matrices, with conclusions on a possible origin and evolution of the genus. The genus evolved from the flood lands with swampy soils and prevalence of dicotyledons (herbaceous Lamiaceae and woody Salicaceae families) to the forest mainland communities with balanced humidity and predominance of herbaceous Poaceae and Fabaceae with woody Fagaceae, Betulaceae, and Oleaceae. The leading factor of the evolutional adaptation to soil-climatic conditions was the factor of humidity, but its significance gradually decreased with the host change to more advanced plant taxa adapted to the communities with more dry balanced humidity. The genus took its origin on the south shores of Laurasia in the Cainozoe. Later, when Hindistant and Arabian Peninsula joined with Laurasia creating the Himalayas barrier, the Pratylenchoides spp. distributed by two branches: the northern one moved into Central Asia, East Europe and North America, and the south branch came into Indo-Malaya, West Asia and the north of Africa. The remnants of the ancient species groups remain in West Europe and East Asia. In the North America the genus gave an origin to its sister genus Apratylenchoides, which spread to the south up to Antarctica; another advanced branch spread in the North America reaching Alaska.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links