Soil Organisms

2008 Issues

Issue 80 (2)   December 2008

6th German Meeting of Acarologists
from 20. – 22. September 2007
at the Zoological Department and Museum,
of the Christian-Albrechts-University Kiel, Germany

 

Preface

Alberti, G., P. Carrera, P. Martin & H. Smit
Comparative spermatology of freshwater mites (Hydrachnidia, Acari)

Bergmann, P., M. Laumann, P. Cloetens & M. Heethoff
Morphology of the internal reproductive organs of Archegozetes longisetosus Aoki (Acari, Oribatida)
 
Dabert, M. & J. Dabert
Ribosomal DNA sequences reveal gregarine pathogens (Apicomplexa: Gregarinia) in mites and other arachnids (Arachnida)
 
Heethoff, M. & P. Cloetens
A comparison of synchrotron X-ray phase contrast tomography and holotomography for non-invasive investigations of the internal anatomy of mites
 
Krisper, G., T. Pfingstl & E. Ebermann
SEM-Investigations on the exochorion of scutoverticid eggs

Laumann, M., P. Bergmann & M. Heethoff
Some remarks on the cytogenetics of oribatid mites

Schmelzle, S., L. Helfen, R. A. Norton & M. Heethoff
The ptychoid defensive mechanism in Euphthiracaroidea (Acari: Oribatida): A comparison of exoskeletal elements
 
Schwaha, T., R. Gith & M. G. Walzl
The nutritive region in the ovaries of astigmatic mites (Acari: Acaridida)
 
Skorupski, M., W. Belter, J. Kamczyc & A. Wierzbicka
Soil mites (Acari, Mesostigmata) of the ‘Torfowiska Doliny Izery’ Reserve in the Sudety Mountains

All articles

Preface

Comparative spermatology of freshwater mites (Hydrachnidia, Acari)

Alberti, G., P. Carrera, P. Martin & H. Smit

Title: Comparative spermatology of freshwater mites (Hydrachnidia, Acari)

Abstract

The ultrastructure of sperm cells of representatives of all superfamilies of Hydrachnidia except Stygothrombioidea is described. The sperm are aflagellate cells with magnitudes reaching 1.3 μm up to 6 μm. They are mostly oval cells, but some show an irregular shape. All investigated mites have an acrosomal complex which is composed of an acrosomal vacuole alone. An acrosomal filament is absent. This character together with a prominent field of granules, likely glycogen, may be regarded as synapomorphic of the groups forming a monophylum Hydrachnidia. All Hydrachnidia except Hydrovolzia and the Eylaoidea possess a rather large acrosomal vacuole to which a thin nuclear process attaches. This arrangement supports the taxon Euhydrachnidia. Further details shown in the fine structure of the sperm cells demonstrate the potential of these characters for the development of a better understanding of the systematic relationships within the Hydrachnidia. However, this needs further studies of more species, which should include Stygothrombioidea and observations of spermatogenesis.

Keywords: chromatin body, acrosomal vacuole, fine structure, systematics, ultrastructure

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Authors

Gerd Alberti
Zoologisches Institut und Museum, Universität Greifswald,
Bachstr. 11/12, 17489 Greifswald, Germany;
alberti@uni-greifswald.de

Patricia Carrera
Catédra de Diversidad Animal I, Universidad Nacional de Córdoba,
Av. Vèlez Sarsfield 299, 5000 Córdoba, Argentina;
pcarrera@com.uncor.edu

Peter Martin
Zoologisches Institut, Tierökologie, Universität Kiel,
Olshausenstr. 40, 24098 Kiel, Germany;
pmartin@zoologie.uni-kiel.de

Harry Smit
Zoological Museum, University of Amsterdam,
Plantage Middenlaan 64, 1018 DH Amsterdam, Netherlands;
smit.h@wolmail.nl

Morphology of the internal reproductive organs of Archegozetes longisetosus Aoki (Acari, Oribatida)

Bergmann, P., M. Laumann, P. Cloetens & M. Heethoff

Title: Morphology of the internal reproductive organs of Archegozetes longisetosus Aoki (Acari, Oribatida)

Abstract

The morphology and three-dimensional organisation of the internal reproductive system of Archegozetes longisetosus is described, using a combination of conventional microscopic methods and the non-invasive technique of synchrotron X-ray microtomography. The reproductive system is described at various points of its development and the differentiation of its components observed. The genital duct forms during tritonymphal stage close to the ventral body wall from different precursors. Previtellogenesis and the differentiation of eugenital lobes start prior to the last moult. Flap-like structures separate the oviducts from the uterus and the uterus from the vagina in the adult stage. We propose a nomenclature for the subdivisions of the ovary.

Keywords: development, ovary, synchrotron X-ray tomography, holotomography

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Authors

Paavo Bergmann
Eberhard–Karls-Universität Tübingen,
Abteilung für Evolutionsbiologie der Invertebraten,
Auf der Morgenstelle 28 E, 72076 Tübingen, Germany;
bergmann_paavo@yahoo.de

Michael Laumann
Eberhard–Karls-Universität Tübingen,
Abteilung für Evolutionsbiologie der Invertebraten,
Auf der Morgenstelle 28 E, 72076 Tübingen, Germany

Peter Cloetens
European Synchrotron Radiation Facility (ESRF),
38043 Grenoble, France

Michael Heethoff
Eberhard–Karls-Universität Tübingen,
Abteilung für Evolutionsbiologie der Invertebraten,
Auf der Morgenstelle 28 E, 72076 Tübingen, Germany

Ribosomal DNA sequences reveal gregarine pathogens (Apicomplexa: Gregarinia) in mites and other arachnids (Arachnida)

Dabert, M. & J. Dabert

Title: Ribosomal DNA sequences reveal gregarine pathogens (Apicomplexa: Gregarinia) in mites and other arachnids (Arachnida)

Abstract

Ribosomal RNA genes are widely applied in phylogenetic studies due to the ubiquitous presence and relative conservation of many regions of their nucleotide sequences. Many specific PCR primers have been developed for amplification of the rDNA cluster fragments from particular taxa. However, the use of universal primers hybridising to the conserved rDNA regions enables discovering sequences of eukaryote endosymbiont or pathogen origin in the analysed DNA sample. This approach makes it possible to detect gregarines (Protozoa: Apicomplexa) that are obligate parasites of digestive tracts and body cavities in invertebrate animals. Here we report new uncultured gregarine clones detected by rDNA sequencing in one harvestmen, Rilaena triangularis (Opiliones: Phalangioidea), and two astigmatid feather mite species, Proctophyllodes stylifer and P. ateri (Acari: Analgoidea). To our knowledge, this is the first record of parasitic Astigmata (cohort Psoroptidia) infected with gregarines. Comparison of the amplified rDNA fragments with sequences deposited in GenBank revealed that analysed sequences corresponded to 18S rDNA from the genera Gregarina (85 and 90 % identity with G. chortiocetes for sequences found in P. ateriand harvestman, and Syncystis (87 % identity with S. mirabilis for sequences found in P. stylifer). The differences observed between nucleotide sequences of the gregarine 18S rDNA fragments indicated that the gregarine isolates from which the sequences were derived belonged to presumably three different species.

Keywords: rDNA, endoparasite, Rilaena triangularisProctophyllodes ateriP. stylifer

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Authors

Mirosława Dabert
Molecular Biology Techniques Laboratory,
Faculty of Biology, Adam Mickiewicz University,
61-712 Poznań, Poland;
Miroslawa.Dabert@amu.edu.pl

Jacek Dabert
Department of Animal Morphology,
Adam Mickiewicz University,
61-712 Poznań, Poland;
Jacek.Dabert@amu.edu.pl

A comparison of synchrotron X-ray phase contrast tomography and holotomography for non-invasive investigations of the internal anatomy of mites

Heethoff, M. & P. Cloetens

Title: A comparison of synchrotron X-ray phase contrast tomography and
holotomography for non-invasive investigations of the internal anatomy of mites

Abstract

Synchrotron X-ray tomography is a powerful tool for non-invasive studies of the internal anatomy of microarthropods. The invention of phase contrast imaging (PCT) enables the visualisation of biological tissues with a small range of attenuation coefficients. Quantitative phase tomography (holotomography; HT) is an advancement of PCT and improves the imaging quality of materials with even smaller differences in attenuation coefficients. In this study, HT was used for the first time to investigate the internal anatomy of microarthropods. Both techniques, HT and PCT, are compared with respect to their ability to differentiate between soft tissues with low attenuation coefficients of the oribatid mite Archegozetes longisetosus (Acari, Oribatida). HT has a higher signal-to-noise ratio and a broader grey value distribution and resolves slight variations in soft tissues much better than PCT.

Keywords: Acari, Oribatida, μCT, X-ray imaging

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Authors

Michael Heethoff
Universität Tübingen,
Abteilung für Evolutionsbiologie der Invertebraten,
Auf der Morgenstelle 28E, 72076 Tübingen, Germany;
Heethoff@gmx.de

Peter Cloetens
European Synchrotron Radiation Facility,
B.P. 220, 38043 Grenoble, France

SEM-Investigations on the exochorion of scutoverticid eggs 

Krisper, G., T. Pfingstl & E. Ebermann

Title: SEM-Investigations on the exochorion of scutoverticid eggs 

Abstract

The exochorion of the eggs of four scutoverticid species – Scutovertex minutusS. sculptusScutovertex sp. (Baltic Coast) and Provertex kuehnelti – were examined using scanning electron microscopy. The egg shell is very complexly structured in all these species, with a species-specific fine structure of the exochorion. S. minutus and S. sculptus eggs show similar but not identical fungiform surface textures, whereas Scutovertex sp. from the Baltic coast deposited eggs with an additional thin external layer. The exochorion of P. kuehnelti eggs has deep pores on its surface; its fine structure differs completely from the egg shells of the other species.

Keywords: Egg shell, endochorion, Oribatida, ProvertexScutovertex

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Authors

Günther Krisper
Institute of Zoology, Karl-Franzens-University,
Universitaetsplatz 2, 8010 Graz, Austria;
guenther.krisper@uni-graz.at

Tobias Pfingstl
Institute of Zoology, Karl-Franzens-University,
Universitaetsplatz 2, 8010 Graz, Austria;
tobias.pfingstl@uni-graz.at

Ernst Ebermann
Institute of Zoology, Karl-Franzens-University,
Universitaetsplatz 2, 8010 Graz, Austria;
ernst.ebermann@uni-graz.at

Some remarks on the cytogenetics of oribatid mites

Laumann, M., P. Bergmann & M. Heethoff

Title: Some remarks on the cytogenetics of oribatid mites

Abstract

The behaviour of the meiotic segregations of the parthenogenetic oribatid mite Archegozetes longisetosus Aoki were investigated in maturing oocytes. Data about the meiotic mechanisms in parthenogenetic oribatid mites are very sparse, although the mechanism of reproduction is fundamental for the restoration of diploidy and has different consequences for the genotype of the offspring. For our analyses we used a combination of traditional methods and the novel technique of synchrotron X-ray holotomography. We describe the points in maturation at which the meiotic segregations occur and the positions of the oocytes at this time in the female genital tract. As the position of the nuclei in the first segregation is located beneath the cell membrane and in the second one central in the cell, we believe to have evidence for an inverted meiotic sequence.

Keywords: Parthenogenesis, holokinetic chromosomes, inverted meiosis, Archegozetes longisetosus, synchrotron X-ray micro-holotomography

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Authors

Michael Laumann
University of Tübingen, Institute of Zoology,
Department of Evolutionary Biology of Invertebrates,
Auf der Morgenstelle 28 E, 72076 Tübingen, Germany;
michael.laumann@uni-tuebingen.de

Paavo Bergmann
University of Tübingen, Institute of Zoology,
Department of Evolutionary Biology of Invertebrates,
Auf der Morgenstelle 28 E, 72076 Tübingen, Germany

Michael Heethoff
University of Tübingen, Institute of Zoology,
Department of Evolutionary Biology of Invertebrates,
Auf der Morgenstelle 28 E, 72076 Tübingen, Germany

The ptychoid defensive mechanism in Euphthiracaroidea (Acari: Oribatida): A comparison of exoskeletal elements

Schmelzle, S., L. Helfen, R. A. Norton & M. Heethoff

Title: The ptychoid defensive mechanism in Euphthiracaroidea (Acari: Oribatida): A comparison of exoskeletal elements

Abstract

Ptychoidy is a mechanical defensive mechanism of some groups of oribatid mites, in which the legs and coxisternum can be completely retracted into the idiosoma and the prodorsum acts as a seal to the encapsulated animal. Here, we use two microscopical techniques, scanning electron microscopy and synchrotron X-ray microtomography, to compare exoskeletal features of two species of ptychoid oribatid mites. Oribotritia banksi and Rhysotritia ardua both belong to the superfamily Euphthiracaroidea and are analysed here in direct comparison to Euphthiracarus cooki, for which the functional morphology has already been described. Rhysotritia ardua and E. cooki – both members of Euphthiracaridae – are similar in most skeletal features that relate to ptychoidy, but differ in the size of their postanal apodemes. Oribotritia banksi – a member of Oribotritiidae – differs from the former two in some well-known features, including the retention of articulations between components of the ventral plates (compared to fused, holoventral plates in Euphthiracaridae), and the absence of interlocking triangles that are associated with the pre- and postanal apodemes in Euphthiracaridae. Our study uncovered two internal skeletal differences in the prodorsum that relate to muscle attachment surfaces: compared to E. cooki and R. arduaO. banksi lacks the sagittal apodeme and has a distinctly smaller manubrium, but only the latter functions in ptychoidy.

Keywords: Synchrotron-X-Ray-Microtomography, Euphthiracarus cookiRhysotritia arduaOribotritia banksi

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Authors

Lukas Helfen
Institute for Synchrotron Radiation, ANKA,
Forschungszentrum Karlsruhe, 76021 Karlsruhe, Germany

Roy A. Norton
State University of New York,
College of Environmental Science and Forestry,
1 Forestry Drive, Syracuse NY 13210, USA

Michael Heethoff
Universität Tübingen, Zoologisches Institut,
Abteilung Evolutionsbiologie der Invertebraten,
Auf der Morgenstelle 28E, 72076 Tübingen, Germany

The nutritive region in the ovaries of astigmatic mites (Acari: Acaridida) 

Schwaha, T., R. Gith & M. G. Walzl

Title: The nutritive region in the ovaries of astigmatic mites (Acari: Acaridida) 

Abstract

The astigmatic ovary consists of a nutritive region surrounded by maturing germ cells. Serial semithinsections and computer-generated 3-D-reconstructions were used to analyse the ovaries of four different astigmatic species (two free living mites, Sancassania berlesei and Glycyphagus domesticus as well as two parasitic ones, Otodectes cynotis and Chorioptes bovis). The nutritive region is always restricted to one end of the ovary: it lies anteriorly in the parasitic species and posteriorly in the free-living species. In one specimen of G. domesticus, one ovary had two nutritive regions. The nutritive regions possess only a single nucleus with evenly distributed nucleoli. The nucleus is composed of several multiply interconnected strands. Altogether, the nutritive region and the general architecture of astigmatic ovaries closely resemble telotrophic meroistic ovaries of insects.

Keywords: 3-D-econstruction, ancassaniaGlycyphagusOtodectesChorioptes

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Authors

Thomas Schwaha
University of Vienna, Faculty of Life Sciences,
Department of Theoretical Biology/section morphology,
Althanstrasse 14, 1090 Vienna, Austria;
thomas.schwaha@univie.ac.at

Rainer Gith
University of Vienna, Faculty of Life Sciences,
Institution of Cell Imaging & Ultrastructure Research,
Althanstrasse 14, 1090 Vienna, Austria;
rainer.gith@univie.ac.at

Manfred G. Walzl
University of Vienna, Faculty of Life Sciences,
Department of Theoretical Biology/section morphology,
Althanstrasse 14, 1090 Vienna, Austria;
manfred.walzl@univie.ac.at

Soil mites (Acari, Mesostigmata) of the ‘Torfowiska Doliny Izery’ Reserve in the Sudety Mountains

Skorupski, M., W. Belter, J. Kamczyc & A. Wierzbicka

Title: Soil mites (Acari, Mesostigmata) of the ‘Torfowiska Doliny Izery’ Reserve in the Sudety Mountains

Abstract

The ‘Torfowiska Doliny Izery’ (Izera Valley Peat bogs) Reserve was established in 2000 and covers 271.39 ha of peat bogs, forests and meadows in Izera River Valley in Izera Mts (Sudety Mts, Poland, SW). This area is one of the largest European complexes of mountain peat bogs with very special microclimate and with the lowest (800 – 840 m above sea level) population of mountain pine in the Sudety Mts. This investigation of Mesostigmata mites is the first in the Reserve. Samples were collected from soil on four different plots: spruce forest, mountain pine forest, peat bogs and a dry meadow. Atotal of 1519 mite specimens of the order Mesostigmata were collected and determined to 53 species. The following species were the most frequent and had the highest number of specimens: Veigaia nemorensisGamasellus montanusTrachytes montanaParagamasus vagabundus and Trachytes pauperior. The species composition of these four various plots was very different. Cheirosieus serratus, Leptogamasus cristulifer, Leptogamasus obesusMixozercon sellnickiParagamasus crassicornutusParagamasus rostriforcepsPergamasus ruehmiPlatyseius italicus and Veigaia mollis are species rarely found in Poland.

Keywords: mountain peat bogs, Sudety Mountains, mites, Acari, Mesostigmata

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Authors

Maciej Skorupski
Department of Game Management and Forest Protection,
University of Life Sciences, Poznań,
ul. Wojska Polskiego 71d, 60-625 Poznań, Poland;
maskorup@au.poznan.pl

Witold Belter
Department of Game Management and Forest Protection,
University of Life Sciences, Poznań,
ul. Wojska Polskiego 71d, 60-625 Poznań, Poland;

Jacek Kamczyc
Department of Game Management and Forest Protection,
University of Life Sciences, Poznań,
ul. Wojska Polskiego 71d, 60-625 Poznań, Poland;

Anna Wierzbicka
Department of Game Management and Forest Protection,
University of Life Sciences, Poznań,
ul. Wojska Polskiego 71d, 60-625 Poznań, Poland;

Issue 80 (1)   August 2008

Collembola, Entomobryidae and Oribatida

Baquero, E. & R. Jordana
Five new species of Entomobrya Rondani, 1861 (Collembola, Entomobryidae) from sacred forests of Juniperus tibetica near Lhasa (NW China)

Bayartogtokh B. & I. E. Smelyansky
Contribution to the knowledge of soil mite genera Zygoribatula and Peloribates (Acari: Oribatida: Oripodoidea) in Central Asia
 
Christian, A. & W. Karg
A revised setal nomenclature based on ontogenetic and phylogenetic characters and universally applicable to the idiosoma of Gamasina (Acari, Parasitiformes)
 
Foissner, W.
Notes on soil ciliates from Singapore, with description of Suturothrix monoarmata nov. gen., nov. spec. (Protozoa, Ciliophora)
 
Potapov, M. & A. Kremenitsa
Comments on the chaetotaxy of the genus Orchesella (Collembola, Entomobryomorpha) with a redefinition of the ’spectabilis‘ group and description of a new species of Orchesella from the Caucasus
 
Russel, D. J.
Collembolan community structures in a continental psammic habitat of south-west Germany
 
Weigmann, G.
Oribatid mites (Acari: Oribatida) from the coastal region of Portugal. I. Peloptulus sacculiferus n. sp., an aberrant species of Phenopelopidae compared with similar European species of the genus 
 
Weigmann, G.
Re-description of Cultroribula berolina Weigmann, 2006 (Acari, Oribatida, Astegistidae) from Germany with a key for the European species

All articles

Five new species of Entomobrya Rondani, 1861 (Collembola, Entomobryidae) from sacred forests of Juniperus tibetica near Lhasa (NW China)

Baquero, E. & R. Jordana

Title: Five new species of Entomobrya Rondani, 1861 (Collembola, Entomobryidae) from sacred forests of Juniperus tibetica near Lhasa (NW China)

Abstract

The taxonomic identification of Collembola collected from two plant species, Juniperus tibetica and Rosa serica, in two sacred juniper forests near Lhasa (NW China), has allowed us to describe five new species of Entomobrya Rondani, 1861.
Only 10 species of the genus Entomobrya have previously been recorded from China, and only one species (E. huangi Chen & Ma, 1998) from Tibet.

Keywords: taxonomy

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Authors

Enrique Baquero
Department of Zoology and Ecology,
University of Navarra, 
PO Box 177, 31080 Pamplona, Navarra, Spain;
ebaquero@unav.es

Rafael Jordana
Department of Zoology and Ecology,
University of Navarra, 
PO Box 177, 31080 Pamplona, Navarra, Spain

Contribution to the knowledge of soil mite genera Zygoribatula and Peloribates (Acari: Oribatida: Oripodoidea) in Central Asia

Bayartogtokh B. & I. E. Smelyansky

Title: Contribution to the knowledge of soil mite genera Zygoribatula and Peloribates (Acari: Oribatida: Oripodoidea) in Central Asia

Abstract

The present paper deals with the members of oribatid mites of the genera Zygoribatula and Peloribates from Central Asia. Two new species, Zygoribatula semicirculata sp. nov. and Z. mongolica sp. nov., collected from dry steppe and mountain-steppe habitats in eastern Kazakhstan and eastern Mongolia, are described on the basis of adults. In addition, supplementary descriptions and illustrations of four known species, Zygoribatula glabra (Michael, 1890), Z. propinqua (Oudemans, 1902), Peloribates robustus Grishina, 1981 and P. pilosus Hammer, 1952 collected from southern Russia and different regions of Mongolia are given. Data on ecology and biogeography of all studied species as well as other species of Zygoribatula and Peloribates recorded in the Central Asian region are discussed.

Keywords: Oribatulidae, Haplozetidae, Kazakhstan, Mongolia, Russia

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Authors

Badamdorj Bayartogtokh
Department of Zoology, Faculty of Biology,
National University of Mongolia, Ulaanbaatar 210646, Mongolia;
bayartogtokh@num.edu.mn

Ilya E. Smelyansky
Siberian Environmental Centre,
P.O. Box 547, Novosibirsk 630090, Russia;
ilya@ecoclub.nsu.ru

A revised setal nomenclature based on ontogenetic and phylogenetic characters and universally applicable to the idiosoma of Gamasina (Acari, Parasitiformes)

Christian, A. & W. Karg

Title: A revised setal nomenclature based on ontogenetic and phylogenetic characters and universally applicable to the idiosoma of Gamasina (Acari, Parasitiformes)

Abstract

The configuration of body setation in a given species is essentially constant and therefore important for diagnosis and determination keys. Previous concepts of setal nomenclature are critically analysed. The majority of these efforts were mostly restricted to a limited taxonomic group and therefore limited in use, although most concepts aimed towards general application. For the revised setal nomenclature, embryonic development was analysed. A decisive process is the formation of the gnathosoma with a separation from the subsequent idiosoma segments. In the anterior part of the idiosoma, the segements of legs I, II, III and IV develop, furthermore those of the genital segment consisting of the fused segments 7 and 8. The posterior part of the idiosoma comprises the segments 9, 10, 11, 12 and 13. The parts of the dorsal shield should be named prodorsum and postdorsum, the parts of the ventral idiosoma sternum and venter. Transverse rows of setae and gland pores allow residues of the ancestral body segmentation to be recognised. On the dorsum of basal derivative Gamasina groups, 10 transverse rows of setae are clearly differentiated. On the dorsum we refer to four pairs of longitudinal rows with a tranverse division in five rows on the prodorsum and five rows on the postdorsum. We define a corresponding setal nomenclature separately for the prodorsum: i1 to i5, z1 to z5, s1 to s5, r1 to r5 and for the postdorsum: I1 to I5, Z1 to Z5, S1 to S5, R1 to R5. This pattern is generally maintained in all superfamilies of Gamasina. However, in single groups certain setae are suppressed or additional setae developed. Also, sometimes setae have changed their positions. The superfamilies of the Gamasina show specialisations concerning habitats and nutrition. According to their evolution, each superfamily has also developed characteristic trends in dorsal setation. This facilitates categorising unknown species. The findings are explained by 27 figures of species grouped into 6 superfamilies.

Keywords: Acari, Gamasina, body setation, setal nomenclature

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Authors

Axel Christian
State Museum of Natural History Goerlitz,
PO Box 300 154, 02806 Goerlitz, Germany;
axel.christian@senckenberg.de

Wolfgang Karg
Hohe Kiefer 152,
14532 Kleinmachnow, Germany

Notes on soil ciliates from Singapore, with description of Suturothrix monoarmata nov. gen., nov. spec. (Protozoa, Ciliophora)

Foissner, W.

Title: Notes on soil ciliates from Singapore, with description of Suturothrix monoarmata nov. gen., nov. spec. (Protozoa, Ciliophora)

Abstract

Few data are available on soil ciliates from Asia. Thus, seven samples were collected in Singapore in February 1987 and investigated between December 1987 and May 1989, using the non-flooded Petri dish method, live observation, and silver impregnation. One hundred and three ciliate taxa, all new for the fauna of Singapore and Malaysia, were found. This applies also to Hemimastix amphikineta, a highly characteristic, euglenid flagellate with Gondwanan distribution. At least three undescribed ciliate species were  discovered,  viz.,  Ottowphrya magna,  which  has  been  published  by  Foissner  (1993),  Dileptus microstoma Vďačný & Foissner (2008), and Suturothrix monoarmata, which is described in the present paper.  The  new  genus  Suturothrix belongs  to  the  order  Haptorida  and  is  unique  in  having  a heteromorphic dorsal brush consisting of three staggered rows, thus forming a suture with the last right side  ciliary  row. Suturothrix monoarmata is  a  slender,  middle-sized  (~  100  x  15  μm)  ciliate  easily recognizable by the single or two thick extrusomes in the centre of the minute oral bulge. The species is not restricted to Asia but has been found also in soil from the Amazon floodplain, Brazil. The objective homonym Obliquostoma Foissner et al., 2002 is replaced by Obliquostomella nom. nov.

Keywords: Asian soil ciliates, Brazil soil ciliates, Dileptus microstomaHemimastix amphikinetaObliquostomella nom. nov., Ottowphrya magna

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Wilhelm Foissner
Universität Salzburg, FB Organismische Biologie,
Hellbrunnerstrasse 34, A-5020 Salzburg, Austria;
wilhelm.foissner@sbg.ac.at

Comments on the chaetotaxy of the genus Orchesella (Collembola, Entomobryomorpha) with a redefinition of the 'spectabilis' group and description of a new species of Orchesella from the Caucasus

Potapov, M. & A. Kremenitsa

Title: Comments on the chaetotaxy of the genus Orchesella (Collembola, Entomobryomorpha) with a redefinition of the ‚spectabilis‚ group and description of a new species of Orchesella from the Caucasus

Abstract

Based on the study of the chaetotaxy of 16 European species of Orchesella a system of notation of groups of macrosetae on head and body is proposed. It mostly corresponds to the system of notation by Jordana & Baquero (2005) for Entomobrya. Some groups of the latter system are not used and several new groups of setae are defined. The ‘spectabilis’ group is redefined, divided into two subgroups, and taxonomical remarks are given for O. bulgaricaO. croaticaO. flavescensO. kervilleiO. pannonicaO. ponticaO. pulchraO. spectabilisO. sphagneticola and O. xerothermica. O. subnigra is synonymised with O. pulchra. The distribution and ecology of species of the ‘sphagneticola’ subgroup are presented. O. stebaevae sp. nov. is described from the Caucasus

Keywords: chaetotaxy notation system, Orchesella stebaevae n.sp.

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Authors

Mikhail Potapov
Biology-chemistry Department,
Moscow State Pedagogical University,
Kibalchicha-6, b.5, Moscow 129278, Russia;
mpnk@orc.ru

Alexander Kremenitsa
South Federal University,
Rostov-on-Don, Russia

Collembolan community structures in a continental psammic habitat of south-west Germany 

Russel, D. J.

Title: Collembolan community structures in a continental psammic habitat of south-west Germany 

Abstract

The present study reports for the first time on the collembolan community composition and structure across a successional gradient in a continental sand habitat. Nine sites – ranging from open sands to a woodland site – in southwest Germany were sampled. Increasing vegetation corresponded significantly with increasing organic matter and nutrient content as well as decreasing pH of the sandy soils, showing a clear eutrophication of the sands along the gradient. Parallel to increasing successional status, the registered microarthropod densities increased and showed a strong shift in group composition. Specifically, the collembolan densities and species numbers also generally increased along the gradient. The open sands showed extremely species-poor communities and strong eudominances of single species, whereas up to 20 species in balanced community structures were found in the most developed sites. Specialised, psammophilous species were largely limited to the open sands and short-grass sites, whereas eurytopic, thermophilous species were for the most part limited to and were dominant in the more highly vegetated and eutrophied sites. Correlation analyses showed a significant connection between soil eutrophication and distribution of these species. Psammophilous taxa, on the other hand, were limited to the nutrient-poor, abiotically extreme sites, which also showed potentially low faunistic competition. These results can be related to theories of A-selection of arthropods from extreme habitats.

Keywords: Collembola, psammophile, sand, succession

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David J. Russell
State Museum of Natural History Goerlitz,
Department Soil Zoological,
PO Box 300 154, 02806 Goerlitz, Germany;
david.russell@senckenberg.de

Oribatid mites (Acari: Oribatida) from the coastal region of Portugal. I. Peloptulus sacculiferus n. sp., an aberrant species of Phenopelopidae compared with similar European species of the genus

Weigmann, G.

Title: Oribatid mites (Acari: Oribatida) from the coastal region of Portugal. I. Peloptulus sacculiferus n. sp., an aberrant species of Phenopelopidae compared with similar European species of the genus

Abstract

The oribatid mite Cultroribula berolina Weigmann, 2006 (Astegistidae), recently briefly described in a determination key, is re-described in more detail and compared with similar congeners. Additionally, taxonomical remarks on the genus and discussions on some species are presented. The main characters of C. berolina are: rostrum distally with three distinct teeth, cusps of lamellae with rounded tips, tutorium blade-like with long acute tip, sensillus long-claviform with short stalk, 10 pairs of fine notogastral setae, legs monodactylous, body length about 255 – 285 μm.

Keywords: Taxonomy, systematics, Europe

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Gerd Weigmann
Institute of Zoology,
Koenigin-Luise-Str. 1 – 3, 14195 Berlin, Germany;
weigmann@zedat.fu-berlin.de

Re-description of Cultroribula berolina Weigmann, 2006 (Acari, Oribatida, Astegistidae) from Germany with a key for the European species

Weigmann, G.

Title: Re-description of Cultroribula berolina Weigmann, 2006 (Acari, Oribatida, Astegistidae) from Germany with a key for the European species

Abstract

A new species of oribatid mites, Peloptulus sacculiferus n. sp., was found in coastal meadows adjacent to  salt  marshes  and  is  described  in  this  paper.  The  species  has  notogastral  sacculi  instead  of  areae porosae, which is unique within the family. The new species is distributed in Portuguese coastal habitats of the Minho River, of the Lagoon of Aveiro and in the south-western Algarve at Cabo São Vicente, but it avoids the salt marsh area. A related species, Peloptulus reticulatus Mihelčič, 1957, occurs at the border of salt marshes in the Lagoon of Faro in southern Portugal. This species is re-described, and P. trinacriae Arcidiacono,  1975,  from  coastal  dunes  in  Sicily  is  declared  a  new  junior  synonym  of  P. reticulatus.

Keywords: Taxonomy, systematics

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Gerd Weigmann
Institute of Zoology,
Koenigin-Luise-Str. 1 – 3, 14195 Berlin, Germany;
weigmann@zedat.fu-berlin.de