Zur Morphologie und Biologie vonCeramium radiculosum Grun

Ohne Zusammenfassung     

Zur Morphologie und Biologie vonCeramium radiculosum Grun

Ohne Zusammenfassung     

Idealistische Morphologie und Phylogenetik. (Zur Methodik der systematischen Morphologie)

Ohne Zusammenfassung     

Zur Morphologie und Entwicklungsgeschichte vonEunotia-Arten (Bacillariophyceae)

After allogamous pairingEunotia tenella produces in each partner cell one gamete containing the two chromatophores of the mother cell and one abortive protoplast without chromatophores. This distribution results from a differential cytokinesis which exhibits the same constant orientation in regard to the epi- resp. hypotheka as in other species ofEunotia. Moreover inEu. tenella andEu. spec. the significant right hand—left hand dissymmetry during the growth of the daughter chromatophores in vegetative cytokinesis is the same as in other species. Both phenomena are significant for the genus and unique. In connection with the diminution of cell size in vegetative divisions the bending of the valvae increases to a certain degree.

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Zur Morphologie und Entwicklungsgeschichte vonEunotia-Arten (Bacillariophyceae)

     

Zur Biologie und Evolution der Lebenserwartung von Tieren

Biodemography is an emerging field of biology. Zoological Gardens can provide a lot of exact data on mean longevity and maximum life-span. The age of certain animal species are connected with their habitat, their ecology, and the taxonomy. Examples for ages and life-cycles are given for many taxonomic units in this article. The relevance for keeping is discussed. In the focus of the visitor's attention many old animals become “animal personalities”. Such charismatic zoo-animals are often elephants, hippopotamuses, bears or great apes.     

Zur Morphologie und Phylogenie der Schizorhynchia (Turbellaria,Kalyptorhynchia)

The proboscis organs of 21 species of Schizorhynchia represent new characters. The meaning of apomorph characters of the proboscis organ and of certain parts of the genital apparatus is discussed. In the phylogenetic system the position of the four families of Schizorhynchia is considered.

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Gefördert durch eine Sachbeihilfe der Deutschen Forschungsgemeinschaft im Schwerpunktprogramm Litoralforschung — Abwassereinflüsse in Küstennahe.     

Zur Kenntnis von Morphologie und Systematik einiger Arten der Gattung Arctodiaptomus Kiefer (Crustacea, Copepoda)

In the present study the author continues the revision of several species of the genus Arctodiaptomus Kiefer. Based on a detailed morphological comparison of animals from 34 different localities the species Arctodiaptomus similis (Baird), A. dudichi Kiefer, A. stephanidesi (Pesta) and A. byzantinus Mann are redescribed. Arctodiaptomus osmanus is characterized as a new species. For A. similis a list of synonyms is given. The centre of distribution of this interesting diaptomid seems to be in Israel, Lebanon and Jordan. Some populations are known also from Iran, Anatolia and Bulgaria. A. byzantinus is found not only in SE-Europe but recently also in the peninsula of Krim. Finally, there are only two habitats known of A. osmanus , both situated in 2 000 m above sea-level in NW Turkey and in Armenia.

Zusammenfassung

Verfasser setzt in der vorliegenden Studie seine Revisionsarbeit an mehreren Arten der Gattung Arctodiaptomus Kiefer fort. Arctodiuptomus similis (Baird), A. dudichi Kiefer, A. stephanidesi (Pesta) und A. byzantinus Mann werden auf Grund neuer vergleichend-morphologischer Untersuchungen eingehend gekennzeichnet und A. osmanus als neue Spezies in die Wissenschaft eingefuhrt. Fur A. similis wird eine Liste von Synonymen rusammengestellt. Der Schwerpunkt der Verbreitung dieses interessanten Diaptomiden scheint in den Landern des ostlichen Mittelmeers zu liegen, namlich in Israel, Libanon und Jordanien. Einzelne Funde stammen auBerdem aus Iran, Zentral- und West-Anatolien sowie aus Bulgarien. A. byrantinus ist nicht nur in Siidosteuropa verbreitet, sondern konnte nunmehr auch fur die Halbinsel Krim nachgewiesen werden. A. osmanusschlieDlich ist vorerst nur aus zwei 2000 m hoch gelegenen Seen in Nordwest-Anatolien und in Armenien bekannt.     

Zur Morphologie und Genese der sog. dunklen Zellen der Nebennierenrinde von Myocastor coypus (Molina)

Zusammenfassung Die Nebenniere des Sumpfbibers weist, insbesondere im Hinblick auf ihre Rindenhisto- und -cytologie sowie die lichtoptisch erfaßbaren dynamischen Prozesse, ein artspezifisches Verhalten auf, das sich in vielfacher Hinsicht von den Verhältnissen bei anderen Nagetierarten unterscheidet.Was das Vorkommen und das Schicksal der sog. dunklen Rindenzellen betrifft, so weichen die Verhältnisse von den bei der Ratte und dem Meerschweinchen erhobenen Befunden offenbar wesentlich ab. Die dunklen Zellen entstehen zweifellos aus normalen Rindenepithelien und treten bei Tieren auf, die keinerlei nachweisbaren innersekretorischen Belastungen ausgesetzt waren. Sie weisen eine morphologisch faßbare Entwicklungsreihe auf, die mit einer partiellen Cytoplasmaverdichtung in Kernnähe beginnt und über eine vollständige Homogenisierung bis zur Koagulation des Cytoplasmas unter Entstehung optisch leerer Spalten verläuft. Der Zellkern zeigt dabei — selbst in der Endphase der Cytoplasmadestruktion — meist keinerlei Veränderungen, die als Ausdruck eines degenerativen Prozesses in Richtung auf einen vollständigen Zelluntergang zu werten wären. Die Befunde sprechen vielmehr dafür, daß die fraglichen Zellen einer weitergehenden Transformation zu Bindegewebselementen unterliegen. Der morphologische Ausdruck einer sog. holokrinen Sekretion dunkler Zellen ist nur selten zu beobachten.     

Interactions between Apion species (Coleoptera: Curculionidae) and Polygonaceae. I. Apion curtirostre Germ, and Rumex acetosa L.

Abstract.

• 1 Apion curtirostre is the commonest weevil attacking Rumex acetosa in the Lancaster area.
• 2 The ovipositional behaviour, larval development, emergence and hibernation of A. curtirostre are described.
• 3 From dissection of samples of stems of R. acetosa, abundance curves for the stages of A. curtirostre and its chalcid parasitoids were constructed and the between-stage mortalities determined.
• 4 There is an exponential relationship between R. acetosa stem height and number of A. curtirostre eggs laid.
• 5 Male stems of R. acetosa appear earlier and are smaller than female stems. Taller stems, at least in female plants, live longer than shorter ones.
• 6 Apion survival is lower in male than in female stems.
• 7 Stem sex is the primary determinant of opposition choice with stem thickness a secondary determinant.
• 8 A. curtirostre eggs introduced experimentally into stems of four Rumex species survived significiantly better in R. acetosa than in any other species. Survival in R. acetosa female plants was twice that in males.
• 9 Survival of A. curtirostre eggs at densities of 4, 8 and 16 per R. acetosa stem was twice that at densities of 32 and 64 per stem.
• 10 The stem size of female R. acetosa was reduced as the number of attacking weevils increased. There was no significant effect in males. No adverse effect on seed production was detected.
• 11 The nature of the relationship between A. curtirostre and R. acetosa is discussed.

     

Studies on predation of Prostephanus truncatus (Horn) (Col., Bostrichidae) and Sitophilus zeamais Mots. (Col., Curculionidae) at different densities on maize by Teretriosoma nigrescens Lewis (Col., Histeridae)

Laboratory experiments using whole cobs were conducted to examine the effect of varying densities of the larger grain borer, Prostephanus truncatus and the maize weevil, Sitophilus zeamais on rate of population increase by the histerid beetle, Teretriosoma nigrescens , a predator primarily of P. truncatus . Densities of all species of insects were determined at the end of the experiment, and an electrophoretic analysis of gut content was conducted on larval and adult T. nigrescens sampled during the experiments. Results indicated that T. nigrescens has a strong preference for P. truncatus and densities of T. nigrescens were associated only with densities of P. truncatus . The maize weevil played little role as an alternative prey or in interfering with T. nigrescens reproduction.     

Sexing adults of the strawberry blossom weevil, Anthonomus rubi (Col., Curculionidae)

Of several previously reported methods for sexing the strawberry blossom weevil, the presence of thorns on the intermediary coxae of males is the most convenient and unambiguous. Uniform pitting on the dorsal elytra of females provides the possible selective pressure for male thorn development.