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  • 1
    Electronic Resource
    Electronic Resource
    Ultrastruktur potentiell photoreceptorischer Zellen unterschiedlicher Organisation bei einem Proseriat (Plathelminthes) (1982)
    Springer
    Zoomorphology 101 (1982), S. 165-175 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Zwei links und rechts im Vorderkörper von Cirrifera aculeata (Ax, 1951) (Proseriata) gelegene Zellen werden als mögliche Photoreceptoren angesprochen. In ein großes intracelluläres Lumen der linken Zelle ragen über 70 nur leicht modifizierte Cilien, daneben treten Mikrovilli und elektronendichte Granula auf. Die vermutlich lichtsensitiven Strukturen der rechten Zelle bilden dicht nebeneinander liegende röhrenartige Vakuolen, vergleichbar den Mikrovilli eines Rhabdoms. Die funktionellen und evolutiven Aspekte dieser beiden bisher unbekannten Zelltypen werden diskutiert.
    Notes: Summary Two cells which lie at the left and at the right near the anterior end of Cirrifera aculeata (Ax, 1951) (Proseriata) are interpreted as presumed photoreceptors. In the left cell up to 70 slightly modified cilia extend into a large intracellular cavity. Besides these cilia microvilli and electron-dense granules are present. The presumed light sensitive structures of the right cell are formed by tubular vacuoles which are arranged without gaps, thus comparable to the microvilli of a rhabdom. The functional and evolutionary aspects of these two cell types are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312431
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  • 2
    Electronic Resource
    Electronic Resource
    Ultrastruktur pericerebraler Cilienaggregate beiDicoelandropora atriopapillata Ax undNotocaryoplanella glandulosa Ax (Turbellaria, Proseriata) (1977)
    Springer
    Zoomorphology 88 (1977), S. 163-174 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Ultrastruktur pericerebral gelegener Cilienaggregate vonDicoelandropora atriopapillata Ax, 1956, undNotocaryoplanella glandulosa (Ax, 1951) wird beschrieben. Die intracellulÄren Aggregate setzen sich jeweils aus mehreren 100 Cilien zusammen, die lückenlos alternierend angeordnet und distal miteinander verflochten sind. Für die Cilienaggregate wird eine photoreceptorische Funktion wahrscheinlich gemacht.
    Notes: Summary The ultrastructure of pericerebrally located ciliary aggregations inDicoelandropora atriopapillata Ax, 1956, andNotocaryoplanella glandulosa (Ax, 1951) is described. The intracellular aggregations consist of some 100 cilia, which are arranged in an alternating position without gaps. The distal parts of the cilia are interweaved. The aggregations are interpreted as photoreceptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01880652
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  • 3
    Electronic Resource
    Electronic Resource
    Development and submicroscopic anatomy of male gametes in Halammovortex nigrifrons (Plathelminthes, Rhabdocoela, ”Dalyellioida”): phylogenetic implications and functional aspects (1998)
    Springer
    Zoomorphology 117 (1998), S. 213-222 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The steps of spermiogenesis and the submicroscopic anatomy of male gametes in Halammovortex nigrifrons are described. During spermiogenesis the cytophore develops pseudopod-like extensions, and bung-like deposits of dark material become attached to the basal bodies of the cilia. During the phase of cell elongation, cilia stay near the edge of the cytophore. Spermatozoa bear two free cilia or flagella. The axonemata are equipped with glycogen islets appearing at regular spaces. The sperm body is characterized by dot-like dense granules linearly arranged, intense glycogen aggregations in a channel-shaped deposition and giant dense bodies. Events of spermiogenesis and the features of mature male gametes in H. nigrifrons corroborate the hypothesis of the existence of a monophylum within the Rhabdocoela encompassing several, but not all taxa of the ”Typhloplanoida” and ”Dalyellioida”. The Dalyelliidae (including the species of the Temnocephalida) belong to this monophylum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050046
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  • 4
    Electronic Resource
    Electronic Resource
    Electron microscopical observations on vitellocytes and germocytes inNematoplana coelogynoporoides (Plathelminthes, Proseriata) (1991)
    Springer
    Zoomorphology 110 (1991), S. 293-300 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Fine-structural features of vitellaria and germaria inNematoplana coelogynoporoides are documented and compared with those of other free-living plathelminths with ectolecithal eggs. Emphasis is mainly put on the pattern of eggshell material, yolk bodies deposited in vitellocytes, and marginal granules of the female germ cells. In this species, encompassed in the taxon Proseriata Unguiphora, the eggshell granules show a meandering pattern also known from species of the taxon Proseriata Lithophora. In contrast, the yolk globules exhibit crystalline components unknown from the Lithophora. The marginal granules in the ooplasm have an extremely large diameter. They consist of a flocculent core and a crescent-shaped cortex. Marginal granules of this appearance have not been found in any other taxon of free-living Neoophora.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01633101
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  • 5
    Electronic Resource
    Electronic Resource
    Ultrastructural studies on vitellocytes of Parotoplaninae (Plathelminthes, Proseriata) with special reference to the structure of eggshell-forming granules (1992)
    Springer
    Zoomorphology 112 (1992), S. 125-131 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The general organisation of the vitellocytes inParotoplana capitata, P. papii, Parotoplanella progermaria, andP. heterorhabditica is described. Special emphasis is put on the substructure of eggshell-forming granules. In all parotoplanid species studied the eggshell granules show uniformly shaped substructures typical of all the Proseriata and besides this feature, globules exist which are bipartite, i.e. two different patterns exist within the same granule. This characteristic, which is unknown for other taxa of the Proseriata, is hypothesized as an autapomorphy of the monophylum Parotoplaninae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01633103
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  • 6
    Electronic Resource
    Electronic Resource
    Struktur und Differenzierung penialer Hartgebilde vonCarenscoilia bidentata Sopott (Turbellaria, Proseriata) (1980)
    Springer
    Zoomorphology 95 (1980), S. 159-167 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Stilettapparatur vonCarenscoilia bidentata Sopott besteht aus mehreren verfestigten Elementen. Diese werden in einem mehrkernigen Matrixsyncytium ausdifferenziert; während der Ontogenese entstehen zuerst periodisch quergestreifte Mikrofibrillen, an die sich elektronendichtes homogenes Material anlagert. Die Wandung der fertig ausgebildeten intracellulären Hartstrukturen besteht aus einer zentralen Lage von Mikrofibrillen, der außen elektronendichte Schichten aufliegen. Hartgebilde mit einer vergleichbaren Feinstruktur sind bisher nur von weiteren proseriaten Turbellarien, nicht jedoch von anderen Plathelminthen bekannt.
    Notes: Summary The stylet apparatus ofCarenscoilia bidentata Sopott consists of five hard elements. These are differentiated in a matrix syncytium. During the ontogeny at first microfibrils with a periodic cross-banding arise; then the microfibrils become enveloped by homogenous electron opaque materials. The wall of the developed intracellular hard elements consists of a central layer with microfibrils and outer layers of electron opaque materials. Hard differentiations with a comparable fine structure are only known from other proseriate turbellarians, but not from other platyhelminthes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00997909
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  • 7
    Electronic Resource
    Electronic Resource
    Ultrastructural observations of the spermiogenesis in the Parotoplaninae (Plathelminthes, Proseriata) with special reference to a striated appendage of the intercentriolar body (1993)
    Springer
    Zoomorphology 113 (1993), S. 191-197 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The spermiogenesis of three species of the Parotoplaninae (Otoplanidae, Proseriata) is described based on electron-microscopical observations. Special reference is given to organelles which do not persist in mature male gametes. One of these organelles is a striated appendage of the intercentriolar body. This differentiation has not been reported from any other plathelminth taxa up to now. The striated appendage, which may serve as a strengthening element, is hypothesized to be an autapomorphic feature of the Parotoplaninae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00394859
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  • 8
    Electronic Resource
    Electronic Resource
    Epidermale Collar-Receptoren der Nematoplanidae und Polystyliphoridae (Plathelminthes, Unguiphora) (1984)
    Springer
    Zoomorphology 104 (1984), S. 226-230 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Für die Nematoplanidae und die Polystyliphoridae (Proseriata) wird ein besonderer Collar-Receptor-Typus beschrieben, der vom Grundmuster der entsprechenden Receptoren der übrigen Proseriata und der Rhabdocoela in zwei Punkten abweicht: (1) Die Receptoren ziehen zwischen Epidermiszellen zur Körperoberfläche. (2) Im distalen Bereich der Receptoren ist im Cytoplasma eine elektronendichte Manschette differenziert. — Zusammen mit anderen Organisationsmerkmalen wird die Manschette dieses Receptor-Typus als Synapomorphie der Nematoplanidae und Polystyliphoridae, des monophyletischen Taxon Unguiphora Sopott-Ehlers, 1984, bewertet.
    Notes: Summary In the Nematoplanidae and the Polystyliphoridae (Proseriata) a special collar receptor type is found, which differs in two points from the basic pattern of these receptors in the other Proseriata and in the Rhabdocoela: (1) The receptors run between epidermal cells to the surface. (2) In the distal region of the receptor cells an electron-dense cuff is developed. The cuff of these receptors, together with some other features of organisation, is considered to be a synapomorphy of the Nematoplanidae and the Polystyliphoridae, which together form the monophyletic taxon Unguiphora Sopott-Ehlers, 1984.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312035
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  • 9
    Electronic Resource
    Electronic Resource
    Ultrastructure of the subepidermal musculature of Xenoturbella bocki, the adelphotaxon of the Bilateria (1997)
    Springer
    Zoomorphology 117 (1997), S. 71-79 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Xenoturbella bocki is the only species of the high-ranked taxon Xenoturbellida. The species lives on marine mud bottoms at a depth of 20–120 m and moves extremely slowly by ciliary gliding. Nevertheless it possesses a well-developed body wall musculature with outer circular muscles, a prominent layer of inner longitudinal muscles and radial muscles that extend from the outer circular myocytes to the musculature surrounding the gastrodermis. The longitudinal myocytes are not compact cells, but form fascicles of fibrils running parallel to each other. Fine cytoplasmic cords connect the fibres of a cell to each other and with its nuclear region. The muscles are embedded within a sometimes expansive extracellular matrix (ECM) that lacks any fibrillar components. All muscle cells display conspicuous and numerous cytoplasmic extensions that are intermingled with each other. Tight coupling between adjacent cell membranes is not found, but zonula adhaerens-like junctions exist. Fibrils belonging to different myocytes, but also fibrils of the same cell, are coupled by such cytoplasmic extensions. Circular, radial and at least the peripheral longitudinal myocytes display cell-matrix connections with the internal lamina, a component of the subepidermal ECM. This internal lamina projects down into the centres of the fascicles with longitudinal muscle fibrils and forms extensive attachment zones with the muscle cells, reminiscent of focal contacts. For the ingestion of food, X. bocki opens the simple mouth pore and protrudes the aciliated gastrodermis. The body wall musculature is responsible for this protrusion and also for the withdrawal of the gastrodermis. In the past, possible phylogenetic kinships with the Acoelomorpha (Plathelminthes) or the Enteropneusta and Holothuroidea were discussed, but, on the basis of all information available, X. bocki is hypothesized to be the sister taxon of the Bilateria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004350050032
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  • 10
    Electronic Resource
    Electronic Resource
    On the spermiogenesis of Invenusta aestus (Plathelminthes, Proseriata) an ultrastructural study with implications for plathelminth phylogeny (1989)
    Springer
    Zoomorphology 109 (1989), S. 145-152 
    Details
    ISSN: 1432-234X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The spermiogenesis of Invenusta aestus (Coelogynoporidae) is described based on electron microscopical observations. Special attention is paid to the intercentriolar body and the anchoring apparatus of the cilia. These organelles are differentiated at the beginning of spermatid maturation and undergo striking changes during gametogenesis. The importance of the organelles mentioned for discussion of phylogenetic relationships within the Plathelminthes is considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312266
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