FOSSILE HIRUDINEA AUS DEM OBERJURA VON BAYERN

The first certain fossil species of Hirudinea, Epitrachys rugosus Ehlers 1869 and Palaeohirudo eichstaettensis n. gen., n. sp., are described from the Upper Jurassic ' Lithographen-Schiefer' of Kehlheim and Eichstätt (Bavaria). Hitherto, Epitrachys rugosus Ehlers 1868 was assigned to Gephyrea Quatrefages. 1847.     

Macromolecular composition of Palaeozoic scolecodonts: insights into the molecular taphonomy of zoomorphs

Dutta, S., Hartkopf‐Fröder, C., Mann, U., Wilkes, H., Brocke, R. & Bertram, N. 2010: Macromolecular composition of Palaeozoic scolecodonts: insights into the molecular taphonomy of zoomorphs. Lethaia, Vol. 43, pp. 334–343. Biogeochemistry and molecular taphonomy of biopolymers of marine zoomorphs are poorly known. In order to obtain insights into this issue we report on the biogeomacromolecular composition of hand‐picked, well‐preserved scolecodonts of Ordovician, Silurian and Devonian age using micro‐Fourier transform infrared (micro‐FTIR) spectroscopy, Curie point pyrolysis‐gas chromatography‐mass spectrometry (Cupy‐GC‐MS) and tetramethylammonium hydroxide (TMAH)‐assisted thermochemolysis‐GC‐MS. The present study reveals that scolecodonts are composed of both aliphatic and aromatic moieties. The micro‐FTIR spectra of scolecodonts are characterized by aliphatic CH_x (3000–2800 and 1460–1450/cm) and CH₃ (1375/cm) absorptions and aromatic C=C (1560–1610/cm) and CH (3050/cm and 700–900/cm) absorptions. The major pyrolysis products from the scolecodonts include aromatic hydrocarbons such as alkylbenzenes, alkylnaphthalenes and alkylphenols. Aliphatic hydrocarbons are represented by a homologous series of n‐alkenes and n‐alkanes. The compounds released upon thermochemolysis with TMAH are saturated and unsaturated fatty acids (as their methyl esters), n‐alkenes/alkanes and aromatic acids (as their methyl esters). No protein/amino acid‐derived compounds have been recognized in the pyrolysates or in the thermochemolysates, and it is concluded that protein/amino acid‐related compounds, which are commonly found in the jaws of extant polychaetes, were destroyed due to diagenetic processes. Obviously, excellent morphological preservation and low thermal alteration are not paralleled by a similar degree of chemical preservation. □Biogeomacromolecules, micro‐FTIR, pyrolysis‐GC‐MS, scolecodonts, thermochemolysis‐GC‐MS.     

Does loss of mass during breeding correlate with reproductive success? A study on Blue Tits Parus caeruleus

Substantial loss of mass of female Blue Tits Parus cueruleus during breeding is commonly explained by three not mutually exclusive explanations: shrinking of gonadal tissues, cost of reproduction and adaptation to save energy during flight. This study showed that loss of body mass was inversely correlated with reproductive success of individual females. Female tarsus length and timing of breeding correlated with loss of body mass, whereas ectoparasite loading had no significant effect on body mass. Loss of body mass during the rearing of young could be a useful measure of cost of reproduction by accounting for individual variation in female quality.     

Impact of gas transport through rice cultivars on methane emission from rice paddy fields

Two Italian rice (Oryza sativa var. japonica) cultivars, Lido and Roma, were tested in the field for methane production, oxidation and emission. In two consecutive years, fields planted with the rice cultivar Lido showed methane emissions 24–31% lower than fields planted with the cultivar Roma. This difference was observed irrespective of fertilizer treatment. In contrast to methane emissions, differences in methane production or oxidation were not observed between fields planted with the two cultivars. Plant-mediated transport of methane from the sediment to the atmosphere was the dominating pathway of methane emission. During the entire vegetation period, the contribution of this pathway to total methane emission amounted to c. 90%, whereas the contribution of gas bubble release and of diffusion through the water column to total methane emission was of minor significance. Results obtained from transport studies of tracer gas through the aerenchyma system of rice plants demonstrated that the root–shoot transition zone is the main site of resistance to plant-mediated gas exchange between the soil and the atmosphere. The cultivar Lido, showing relatively low methane emissions in the field, had a significantly lower gas transport capacity through the aerenchyma system than the cultivar Roma. Thus, the observed differences in methane emissions in the field between the cultivars Lido and Roma can be explained by different gas transport capacities. Apparently, these differences in gas transport capacities are a consequence of differences in morphology of the aerenchyma systems, especially in the root–shoot transition zone. It is, therefore, concluded that identification and use of high-yielding rice cultivars which have a low gas transport capacity represent an economically feasible, environmentally sound and promising approach to mitigating methane emissons from rice paddy fields.