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1

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Ultrastructural investigations on the spermatozoon and its genesis in Aeolosoma litorale with considerations on the phylogenetic implications for the aeolosomatidae (annelida)

Bunke, D.

Amsterdam : Elsevier

Journal of Ultrastructure Research and Molecular Structure Research 95 (1986), S. 113-130

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ISSN: 0889-1605

Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Topics: Biology

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1016/0889-1605(86)90035-2

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Ultrastructure of the metanephridial system in Aeolosoma bengalense (Annelida) (1994)

Bunke, D.

Springer

Zoomorphology 114 (1994), S. 247-258

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ISSN: 1432-234X

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Summary The excretory system of Aeolosoma bengalense has been examined by light and electron microscopy. The system consists of seven serially arranged paris of metanephridia and six pairs of podocytes (referring to the first zoid of an animal chain). The podocytes surround blood spaces of the alimentary canal forming dorsoventrally running loops that emerge on both sides of it. The two elements of the system have a correlative position, each podocyte extending in close proximity to the funnel of a metanephridium. Only in the region of the first metanephridia are podocytes lacking. The nephrostome of the metanephridia consists of two cells, an inner one, the terminal duct cell, and an outer one enwrapping it, called the mantle cell. Nephrostomal cilia that extend into the coelomic space arise exclusively from the rim of the mantle cell whereas those of the terminal duct cell arranged on its luminal surface protrude into the canal forming a flame. The nephridial canal is ciliated throughout and is either intra- or extracellular. Its initial loops aggregate to form a compact organ, the nephridial body. The middle part of the duct constitutes a loop that ascends at each side of the alimentary canal where it is in intimate contact with its blood spaces. Ultrastructural features of the duct cells suggest a reabsorptive function in two regions, the nephridial body and the uppermost part of the loop. The terminal part of the duct passes through the nephridial body and opens ventrolaterally. Generally, the transverse vascular loops at the gut consist of one podocyte each. In the oesophageal region, where only one pair of podocytes is present, the loops connect the dorsal with the ventral longitudinal vessel. Three pairs of podocytes are present in the dilated region of the intestine emerging from its lateral wall and joining the median ventral vessel or blood spaces near by. In the hind gut, where two pairs of podocytes occur, the loops arise from the dorsolateral part and enter directly the ventral vessel. Cytological features of podocytes resemble those of other animals. The results are discussed on the basis of current theories on the function and the phylogenetic significance of excretory systems in the Annelida.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00416863

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Ultrastructure of the preseptal part of metanephridia in Nais variabilis and Dero digitata (Annelida, Clitellata) (2000)

Bunke, D.

Springer

Zoomorphology 120 (2000), S. 39-46

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ISSN: 1432-234X

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract The composition and arrangement of cells in the preseptal region of metanephridia have been examined by ultrastructural methods in two naidid species, Nais variabilis and Dero digitata. Within this region special attention has been paid to the portion around the orifice and the region where the metanephridium penetrates the septum. In N. variabilis, the preseptal region is composed of four cells and, in D. digitata, three cells are present. In both species three cells correspond in position and ultrastructural details and, hence, are interpreted as homologous. These are the mantle cell, the flame cell, and the canal cell. The mantle cell covers the preseptal region and surrounds the opening. The margin around the orifice is endowed with cilia, which extend into the coelomic space and beat irregularly. They do not enter the orifice and, thus, are not part of the internal ciliary flame. Posteriorly, in D. digitata, the mantle cell originates from the septal wall, i.e., its extensions spread in the plane of the frontal coelothelium of the septum. In N. variabilis, the mantle cell is continued by a further cell, enwrapping the posterior region of the preseptal part. This cell, called the septal cell, is anchored in the septal wall like the mantle cell in D. digitata. Both cells are interpreted as mesodermal components of the metanephridium. The flame cell lies beneath the mantle cell. In front, on its dorsal wall, many cilia are inserted which extend posteriorly into the nephridial canal forming a flame. In D. digitata, the caudal extension of this cell was examined in more detail; it originates from an intraseptal position. The canal cell lines the anterior lumen of the nephridial duct. While the mantle cell and flame cell enclose the organ from a dorsal position, the canal cell lies opposite embracing the lumen from a ventromedial position. Behind, it extends into the postseptal region for a certain distance. It is concluded that metanephridia in the Clitellata have a coelothelial component and, probably, are not just descendants of a single cell, the nephridioblast. The results further indicate that a flame cell and a mantle cell or some corresponding coelothelial cells may be constitutive elements of the ground plan of the clitellate metanephridium. Phylogenetic consequences for non-clitellate Annelida are discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s004350000023

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Aeolosoma maritimum nov. spec., die erste Salzwasserart aus der Familie Aeolosomatidae (Annelida: Oligochaeta) (1970)

Westheide, W. ; Bunke, D.

Springer

Helgoland marine research 21 (1970), S. 134-142

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ISSN: 1438-3888

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Description / Table of Contents: Zusammenfassung 1.Aeolosoma maritimum nov. spec. wurde im Mesopsammal eines Sandstrandes am Golf von Tunis gefunden; der Salzgehalt im Porenwasser der Probestellen lag zwischen 29,2 und 34,6 ‰. 2. Die Tiere meiden die oberflächlichen Regionen des Strandes; die meisten Individuen wurden unmittelbar über oder im Grundwasserbereich gefangen, in einer Entfernung von etwa 4 m von der Wasserlinie. 3. Die Art repräsentiert somit die erste marine Form aus der Oligochaeten-Familie Aeolosomatidae. Aus den ökologischen Daten andererAeolosoma-Species kann ein Einwanderungsweg aus dem limnischen Mesopsammal über das Brackwasser in das marine Sandlückensystem rekonstruiert werden. 4. Merkmale der äußeren und inneren Organisation weisenA. maritimum ebenfalls als eine gut definierte Art aus.

Notes: Abstract Aeolosoma maritimum nov. spec. is the first marine species of the family Aeolosomatidae. The animals were found in the mesopsammal of a Tunisian sandy beach at the Gulf of Tunis; the salinity of the habitat ranged from 29.2 to 34.6 ‰. Investigations on the vertical and horizontal distribution revealed that the species avoids surface layers of the beach. Most individuals occur in the region above subsoil water level, 4 m off the water line. The most important eidonomic features ofA. maritimum are: length up to 4 mm; only one single field of cilia on the ventral side of the prostomium; no special ciliary pits; orange-yellow epidermic glands; hair bristles only, 3–5 per bundle, up to 115 µm; widening of the intestine between the second and third or the third and fourth bundles. No distinct division in zooids could be seen; if paratomy occurs, the new individuals do not separate before the 10th segment. The ecology of the genusAeolosoma provides an excellent example for the migration of limnic elements into marine habitats.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01630521

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Darstellung und Reaktionen von methylenverbrückten Phosphor(III)-Phosphor(V)-Verbindungen (1988)

Fild, M. ; Bunke, D. ; Schomburg, D.

Weinheim : Wiley-Blackwell

Zeitschrift für anorganische Chemie 566 (1988), S. 90-102

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ISSN: 0044-2313

Keywords: Chemistry ; Inorganic Chemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology

Description / Table of Contents: Preparation and Reactions of Methylene-bridged Phosphorus(III)-Phosphorus(V) CompoundsThe synthesis of methylene-bridged diphosphorus compounds of the type Y2PCH2P(S)X2 (with Y = F, Cl, OPri, NMe2, Ph) is reported. Reactions of these compounds with bicycloheptadiene-metaltetracarbonyls to form complexes of the type (L—L′)M(CO)4 and (L—L′)2M(CO)4, respectively, as well as some oxidation reactions and the conversion of the phosphine F2PCH2P(S)F2 to the cyclotetraphosphine [PCH2P(S)F2]4 are described.

Notes: Über die Darstellung von methylenverbrückten Diphosphorverbindungen der Zusammensetzung Y2PCH2P(S)X2 (mit Y = F, Cl, OPri, NMe2, Ph; X = F, OPri, NMe2, Ph) wird berichtet. Umsetzungen der erhaltenen Verbindungen mit Bicycloheptadien-Metalltetracarbonylen zu Komplexen des Typs (L—L′)M(CO)4 bzw. (L—L′)2M(CO)4 (mit M = Cr, Mo, W), einige Oxidationsreaktionen und die Umwandlung des Phosphans F2PCH2P(S)F2 zum Cyclotetraphosphan [PCH2P(S)F2]4 werden beschrieben.

Additional Material: 1 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/zaac.19885660113

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