143 research outputs found
Nannodromus reveilleti (Acari, Anystida, Saxidromidae) a new genus and species from South Africa
The description of a new genus Nannodromus and a new species Nannodromus reveilleti (Acari: Anystides: Saxidromidae) from South Africa, based on adult males and females.Fil: Fernandez, Nestor Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Rioja; ArgentinaFil: Coineau, Yves. Muséum National d’Histoire Naturelle; FranciaFil: Theron, Pieter. North-West University; SudáfricaFil: Tiedt, Louwrens. North-West University; Sudáfric
Family Carabodidae (Acari: Oribatida) V. The genus Congocepheus Balogh, 1958 (second part), with a redescription of Congocepheus involutus Mahunka, 1997, and descriptions of two new species
The species Congocepheus involutus Mahunka, 1997 is redescribed, and two newspecies are described, Congocepheus gabonensis n. sp. and Congocepheus ektactesin. sp., using optical and scanning electron microscopy.La Famille Carabodidae (Acari: Oribatida) V. Le genre Congocepheus, Balogh, 1958 (deuxième partie) avec la redescription de Congocepheus involutus Mahunka, 1997 et les descriptions de deux nouvelles espèces.
L'espèce Congocepheus involutus Mahunka, 1997 est redécrite et deux espèces nouvelles sont décrites Congocepheus gabonensis n. sp. et Congocepheus ektactesi n. sp. sur la base d'observations en microscopie optique et électronique à balayage.Fil: Fernandez, Nestor Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Rioja; ArgentinaFil: Theron, Pieter. North-West University; SudáfricaFil: Rollard, Christine. Centre National de la Recherche Scientifique; Francia. Museum National D; FranciaFil: Tiedt, Louvrens. North-West University; Sudáfric
Fine structure of the male genital systems, spermatophores and unusual sperm cells of saxidromidae (Acari, Actinotrichida)
The early derivative actinedid Saxidromidae, Saxidromus delamarei, Bovidromus roussouwi, and Rhinodromus lootsi perform indirect spermatophore transfer by means of a peculiar mating behaviour. The anatomy and fine structure of the male genital systems are described and are shown to exhibit the organisation considered to be fundamental in Actinotrichida: paired testes with germinal and glandular parts, paired vasa deferentia, unpaired ejaculatory duct, progenital chamber containing genital papillae. The genital system is located ventral of the digestive tract. The testes produce relatively few or even very few aflagellate sperm cells, which represent synspermia consisting of likely four undivided sperm cell equivalents in a common cytoplasm. Whereas S. delamarei produces a rather large stalked spermatophore containing many synspermia, both the other species produce very tiny stalked spermatophores with a spherical head representing only one synspermium. Thus, in these latter species only one synspermium is transferred to the female at atime, but the male can convey several (possibly five or more) spermatophores to the female during the mating session. A scenario is suggested which could describe the evolution of this remarkable mating system and behaviour.Fil: Alberti, Gerd. ERNST MORITZ ARNDT UNIVERSITÄT GREIFSWALD (UG);Fil: Coineau, Yves. Muséum National d'Histoire Naturelle; FranciaFil: Fernández, Néstor Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Théron, Pieter D.. North-West University; Sudáfric
Revision of the family Carabodidae (Acari, Oribatida) VII. Redefinition of the genus Malgasodes; redescription of M. curvisetus Mahunka, 2000; and complementary description of M. hungarorum Mahunka, 2010. Phylogenetic relationships between Malgasodes, Bovicarabodes, Afticarabodes, Congocepheus and Cavaecarabodes are discussed
The genus Malgasodes is redefined; the type species M. curvisetus Mahunka, 2000, is redescribed by meansof studies using optic and Scanning Electron Microsopy (SEM), and a complementary description of M.hungarorum Mahunka, 2000 is included. Comparison of genera Malgasodes Mahunka, 2000, Bovicarabodes Fernandez, Theron, Rollard, 2013a, Cavaecarabodes Fernandez, Theron, Rollard, Rodriguez Castillo,2014, Afticarabodes Fernandez, Theron, Rollard, 2013b, and Congocepheus Balogh, 1958 is made. Problems concerning chaetotaxy, regressive evolution and neotrichy are explained and phylogenetic relationships between Malgasodes, Bovicarabodes, Afticarabodes, Congocepheus and Cavaecarabodes are discussed.Fil: Fernández, Néstor Alfredo. North-West University. Research Unit for Environmental Sciences and Management; Sudáfrica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Theron, Pieter. North-West University. Research Unit for Environmental Sciences and Management; SudáfricaFil: Rollard, Christine. Muséum National d; FranciaFil: Castillo, Elio Rodrigo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentin
The family Carabodidae (Acari, Oribatida) VIII: The genus Machadocepheus (first part) Machadocepheus leoneae sp. n. and Machadocepheus rachii sp. n. from Gabon
The genus Machadocepheus, being one of the more complex genera of the Carabodidae family, is briefly outlined to demonstrate this complexity. Descriptions of two new species from Gabon, M. leoneae sp. n. and M. rachii sp. n. are given.Fil: Fernández, Néstor Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; ArgentinaFil: Theron, Pieter. North West University; SudáfricaFil: Rollard, Christine. North West University; SudáfricaFil: Leiva, Sergio. Instituto Nacional de Tecnología Agropecuaria; Argentin
Ecological changes in historically polluted soils: Metal(loid) bioaccumulation in microarthropods and their impact on community structure
International audienceSoil pollution by persistent metal(loid)s present environmental and sanitary risks. While the effects of metal(loid)s on vegetation and macrofauna have been widely studied, their impact on microarthropods (millimetre scale) and their bioaccumulation capacity have been less investigated. However, microarthropods provide important ecosystem services, contributing in particular to soil organic matter dynamics. This study focussed on the impact of metal(loid) pollution on the structure and distribution of microarthropod communities and their potential to bioaccumulate lead (Pb). Soil samples were collected from a contaminated historical site with a strong horizontal and vertical gradient of Pb concentrations. Microarthropods were extracted using the Berlese method. The field experiments showed that microarthropods were present even in extremely polluted soils (30,000 mg Pb kg− 1). However, while microarthropod abundance increased with increasing soil C/N content (R2 = 0.79), richness decreased with increasing pollution. A shift in the community structure from an oribatid-to a springtail-dominated community was observed in less polluted soils (R2 = 0.68). In addition, Pb bioamplification occurred in microarthropods, with higher Pb concentrations in predators than in detritivorous microarthropods. Finally, the importance of feeding and reproductive ecological traits as potentially relevant descriptors of springtail community structures was highlighted. This study demonstrates the interest of microarthropod communities with different trophic levels and ecological features for evaluating the global environmental impact of metal(loid) pollution on soil biological quality
The evolution of epigean and stygobitic species of Koonunga Sayce, 1907 (Syncarida: Anaspidacea) in Southern Australia, with the description of three new species
Three new species of Koonunga were discovered in surface and subterranean waters in southern Australia, and were defined using mtDNA analyses and morphology. The new species are: Koonunga hornei Leijs & King; K. tatiaraensis Leijs & King and K. allambiensis Leijs & King. Molecular clock analyses indicate that the divergence times of the species are older than the landscape that they currently inhabit. Different scenarios explaining this apparent discrepancy are discussed in the context of the palaeography of the area. A freshwater epigean origin for Koonunga is considered the most likely hypothesis, whereby some lineages made the transition to the subterranean environment within the last few million years influenced by significant climatic cooling/drying. We discuss the possibility that one stygobitic lineage secondarily regained some of its body pigmentation as adaptation to increased photic conditions after cave collapse and forming of cenotes during the last glacial maximum.Remko Leijs, Tessa Bradford, James G. Mitchell, William F. Humphreys, Steven J. B. Cooper, Peter Goonan, Rachael A. Kin
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