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  • 11
    Electronic Resource
    Electronic Resource
    Functional aspects of the intercentriolar body in the spermiogenesis of Nematoplana coelogynoporoides (Plathelminthes, Proseriata) (1990)
    Springer
    Zoomorphology 109 (1990), S. 245-249 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The intercentriolar body in the biciliary spermatids of Nematoplana coelogynoporoides and its changes during spermiogenesis are described. Different functional aspects of the body, for example its presumed role as microtubule-organising centre and its influence on cell elongation, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312191
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  • 12
    Electronic Resource
    Electronic Resource
    Organization of statocysts in the Otoplanidae (Plathelminthes): an ultrastructural analysis with implications for the phylogeny of the Proseriata (1990)
    Springer
    Zoomorphology 109 (1990), S. 309-318 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The statocyst of otoplanids is enveloped by a bipartite capsule which consists of two different extracellular matrices. This capsule encircles three different types of aciliary cells: several peripherally located flattened parietal cells, one central statolith forming cell (lithocyte) and two clusters of accessory cells. Intracapsular lumina exist which are different from extracapsular intercellular spaces. The accessory cells most probably represent those structures that are mainly involved in nervous conduction. These cells extend cytoplasmatic processes towards different peripheral regions of the statocyst where processes of outer nerve cells penetrate the capsule. The statocyst does not seem to represent a more evolved equilibrium receptor system but may function as a relatively simple aciliary sense organ suitable for positive geotactic behaviour. The otoplanid statocyst corresponds to statocysts in other lithophorous proseriates but not to statocysts in other taxa of the free-living Plathelminthes. The monophyly of a taxon Lithophora within the Proseriata is corroborated by this autapomorphic characteristic.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00803571
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  • 13
    Electronic Resource
    Electronic Resource
    Photoreceptors with mitochondrial lenses inPogaina suecica (Plathelminthes, Rhabdocoela) (1992)
    Springer
    Zoomorphology 112 (1992), S. 11-15 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The photoreceptors ofPogaina suecica correspond to the type of pigment cup ocelli. Each eye consists of one cup cell and three sensory cells. The most conspicuous differentiations of these eyes are lens elements formed by giant mitochondria densely filled with homogeneous electron-dense material. From electron microscopical findings available to date it is hypothesized that mitochondrial lensing might be an autapomorphy of a taxon comprising the Provorticidae Kirgisellinae, Dalyelliidae and Graffillidae groups which are ascribed to the paraphyletic “Dalyellioida”.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01632990
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  • 14
    Electronic Resource
    Electronic Resource
    Die Feinstruktur der Sehkolben und der Lamellarkörper von Parotoplana capitata (Plathelminthes, Proseriata) (1986)
    Springer
    Zoomorphology 106 (1986), S. 44-48 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary The ultrastructure of intracerebral visual clubs and the fine structure of presumed photoreceptive lamellate bodies from the cerebral region of Parotoplana capitata are described. The rhabdomeric elements of the visual clubs exhibit a tripartite configuration. Some microvilli are mingled with the cilia of the lamellate bodies. The evolutionary aspects of the visual clubs and of the lamellate bodies are discussed. The absence of pigment granules within the mantle cell of the visual clubs form an autapomorphy of the Proseriata Lithophora. Ciliary lamellate bodies represent an autapomorphy of the subordinated taxon Parotoplaninae.
    Notes: Zusammenfassung Die Ultrastruktur der intracerebralen Sehkolben und die der potentiell photoreceptorischen Lamellarkörper aus der Cerebralregion von Parotoplana capitata werden dargestellt. Die Konfiguration der Rhabdomeren der Sehkolben zeigt eine deutliche Terzettbildung. Zwischen die Cilien der Lamellarkörper schieben sich einige Mikrovilli. Die Bedeutung der pigmentfreien Sehkolben und der Lamellarkörper in evolutiver Hinsicht wird diskutiert. Der Mangel von Pigmentgranula in der Mantelzelle der Sehkolben bildet eine Autapomorphie der Proseriata Lithophora. Ciliäre Lamellarkörper repräsentieren vermutlich eine Autapomorphie des Teiltaxons Parotoplaninae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00311946
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  • 15
    Electronic Resource
    Electronic Resource
    Monociliary receptors in interstitial Proseriata and Neorhabdocoela (Turbellaria Neoophora) (1977)
    Springer
    Zoomorphology 86 (1977), S. 197-222 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of monociliary receptors in 10 species of the Proseriata and Neorhabdocoela is described, with particular reference to the epidermal dendritic part. Sensory cells with a single kinocilium situated at the level of the distal epidermis membrane are considered as mechano- or chemoreceptors. There exist sensory cells with a dendrite penetrating one epidermis cell and bearing an embedded kinocilium and a collar of 8 stereocilia or ridges with a fribrillose substructure. These collared receptors probably function as mechanoreceptors. In comparison with collared sensory cells in species of other turbellarian orders, the embedded receptors in the Proseriata and Neorhabdocoela are more advanced and possess synapomorphous characteristics. With the embedded receptors a new evidence is given for the close phylogenetic relationship between the Proseriata and Neorhabdocoela. The distribution of collared cells in the animal system and their phylogenetic implication for a choanoflagellate origin of the Metazoa are briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00993666
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  • 16
    Electronic Resource
    Electronic Resource
    A new type of photoreceptor in Anthopharynx sacculipenis (Plathelminthes, Solenopharyngidae) (1995)
    Springer
    Hydrobiologia 305 (1995), S. 177-182 
    Details
    ISSN: 1573-5117
    Keywords: Solenopharyngidae ; photoreceptors ; lamellate organelles ; Plathelminthes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The unpaired eye of A. sacculipenis consists of two sensory cells and one pigmented mantle cell. The light-sensing organelles are formed by flattened and rolled lamellae, which are not of ciliary origin but derive from the surface membrane of the sensory cells. The pigment of the mantle cell appears black in living animals, but electron-lucent in the EM picture. The significance of these special features is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00036383
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  • 17
    Electronic Resource
    Electronic Resource
    Comparative morphology of photoreceptors in free-living plathelminths — a survey (1991)
    Springer
    Hydrobiologia 227 (1991), S. 231-239 
    Details
    ISSN: 1573-5117
    Keywords: free-living Plathelminthes ; photoreceptors ; morphology ; ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In free-living Plathelminthes, the best-known photoreceptors are pigment-cup ocelli, eyes formed of one or several pigmented supportive cells into whose cup-shaped cavity project the light-sensitive elements of one or several sensory cells. Besides these, so-called Sehkolben, photoreceptors lacking pigment granules, are found in some species. Sensory cells in plathelminth photoreceptors most commonly use microvilli as the light-sensitive organelles, but some use cilia and combinations of microvilli and cilia. Lamellate ciliary bodies with cilia whose membranes are strongly flattened and rolled and pericerebral ciliary aggregations with interwoven cilia protruding into an intracellular cavity are likely photoreceptors in that they show amplification of membrane likely to bear photoreceptive pigments. Cells with ballooned cilia and tubular vacuoles are other differentiations to which light-sensitivity has been attributed. A variety of structures serve as lenses, all usually formed from parts of the pigment cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027607
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  • 18
    Electronic Resource
    Electronic Resource
    Plathelminthes or Platyhelminthes? (1995)
    Springer
    Hydrobiologia 305 (1995), S. 1-2 
    Details
    ISSN: 1573-5117
    Keywords: Plathelminthes ; Platyhelminthes ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00036354
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  • 19
    Electronic Resource
    Electronic Resource
    Fine-structural characteristics of female and male germ cells in Proseriata Otoplanidae (Platyhelminthes) (1986)
    Springer
    Hydrobiologia 132 (1986), S. 137-144 
    Details
    ISSN: 1573-5117
    Keywords: Platyhelminthes ; ultrastructure ; germocytes ; vitellocytes ; spermatozoa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fine-structural features of female germ cells differentiating within the germaria of Otoplanella baltica and Notocaryoplanella glandulosa are documented and compared with those of other free-living platyhelminths having ectolecithal eggs. In these species, encompassed in the taxon Proseriata Lithophora, insemination of the germocytes occurs within the germaria. A sperm cell, that has penetrated a germocyte differs in special features from mature male germ cells found in the testes, in parts of the male genital system, or even in other regions of the organism. The hypothesis that dense bodies correspond to acrosomal material is supported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00046240
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  • 20
    Electronic Resource
    Electronic Resource
    Ultrastructural observations on paracnids. I: Coelogynopora axi Sopott (Turbellaria, Proseriata) (1981)
    Springer
    Hydrobiologia 84 (1981), S. 253-257 
    Details
    ISSN: 1573-5117
    Keywords: Turbellaria ; Proseriata ; Coelogynoporidae ; ultrastructure ; paracnids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ‘Schlauchdrüsen’ or paracnids of Coelogynopora axi Sopott, 1972 consist of two components: a muscle cell and a secretory cell. The secretory cell is provided with a tube, which bears a border of microvilli. In the normal position the tube is situated in the interior of the secretory cell, and the microvilli stand at the inner side of the tube. After expulsion of the tube the microvilli are situated at its free surface. The evagination takes place in response to chemical stimuli and is effected by the contraction of the myofibrils of the muscle cell. The paracnids are supposed to be mechanisms of defense. However, conformities with nematocysts and spirocysts of the cnidarians do not exist. The paracnids in other species of the Coelogynoporidae, for example in Invenusta paracnida (Karling, 1966) and Carenscoilia bidentata Sopott, 1972 differ from those of C. axi in many details.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00026187
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