Historical and recent investigations on the bee fauna of Taiwan (Hymenoptera, Apoidea)

The bee fauna of Taiwan was studied intensively in the first half of last century and was based in large parts on the extensive material collected by Hans Sauter between 1902 and 1914. Subsequent studies on bees of Taiwan have only been sporadic. Within a cooperation between the above mentioned institutions the bee fauna was reinvestigated. It was shown how insufficiently the bee fauna of Taiwan had been investigated so far, in particular, the higher mountain regions. Now about 150 species of bees, belonging to 32 different genera, are known from Taiwan, ten of which have been described or recognized as new for science by the recent cooperation

The structure of mollusc larval shells formed in the presence of the chitin synthase inhibitor Nikkomycin Z

Background Chitin self-assembly provides a dynamic extracellular biomineralization interface. The insoluble matrix of larval shells of the marine bivalve mollusc Mytilus galloprovincialis consists of chitinous material that is distributed and structured in relation to characteristic shell features. Mollusc shell chitin is synthesized via a complex transmembrane chitin synthase with an intracellular myosin motor domain. Results Enzymatic mollusc chitin synthesis was investigated in vivo by using the small-molecule drug NikkomycinZ, a structural analogue to the sugar donor substrate UDP-N-acetyl-D-glucosamine (UDP-GlcNAc). The impact on mollusc shell formation was analyzed by binocular microscopy, polarized light video microscopy in vivo, and scanning electron microscopy data obtained from shell material formed in the presence of NikkomycinZ. The partial inhibition of chitin synthesis in vivo during larval development by NikkomycinZ (5 μM – 10 μM) dramatically alters the structure and thus the functionality of the larval shell at various growth fronts, such as the bivalve hinge and the shell's edges. Conclusion Provided that NikkomycinZ mainly affects chitin synthesis in molluscs, the presented data suggest that the mollusc chitin synthase fulfils an important enzymatic role in the coordinated formation of larval bivalve shells. It can be speculated that chitin synthesis bears the potential to contribute via signal transduction pathways to the implementation of hierarchical patterns into chitin mineral-composites such as prismatic, nacre, and crossed-lamellar shell types

The structure of mollusc larval shells formed in the presence of the chitin synthase inhibitor Nikkomycin Z

Background: Chitin self-assembly provides a dynamic extracellular biomineralization interface. The insoluble matrix of larval shells of the marine bivalve mollusc Mytilus galloprovincialis consists of chitinous material that is distributed and structured in relation to characteristic shell features. Mollusc shell chitin is synthesized via a complex transmembrane chitin synthase with an intracellular myosin motor domain. Results: Enzymatic mollusc chitin synthesis was investigated in vivo by using the small-molecule drug NikkomycinZ, a structural analogue to the sugar donor substrate UDP-N-acetyl-D-glucosamine (UDP-GlcNAc). The impact on mollusc shell formation was analyzed by binocular microscopy, polarized light video microscopy in vivo, and scanning electron microscopy data obtained from shell material formed in the presence of NikkomycinZ. The partial inhibition of chitin synthesis in vivo during larval development by NikkomycinZ (5 μM — 10 μM) dramatically alters the structure and thus the functionality of the larval shell at various growth fronts, such as the bivalve hinge and the shell's edges. Conclusion: Provided that NikkomycinZ mainly affects chitin synthesis in molluscs, the presented data suggest that the mollusc chitin synthase fulfils an important enzymatic role in the coordinated formation of larval bivalve shells. It can be speculated that chitin synthesis bears the potential to contribute via signal transduction pathways to the implementation of hierarchical patterns into chitin mineral-composites such as prismatic, nacre, and crossed-lamellar shell types

Klärung und Neubeschreibung der Sandbiene Andrena asiatica Friese, 1921 (Hymenoptera: Apidae, Andreninae).

Andrena asiatica Friese, 1921 wird wiederbeschrieben und ein Lectotypus wird festgelegt. Die von Warncke 1975 beschriebene, heller behaarte Unterart A. asiatica oxyura Warncke, 1975 ist ein Synonym der Nominatform (syn. n.). A. asiatica gehört nicht in die Untergattung Nobandrena, sondern ist vermutlich mit A. formosa Morawitz, 1878 und A. combusta Morawitz, 1876 verwandt.Nomenklatorische Handlungenasiatica Friese, 1921 (Andrena), LectotypeAndrena asiatica Friese, 1921 is redescribed and a lectotype is designated. The brighter haired subspecies, A. asiatica oxyura Warncke, 1975 is a synonym of the nominate form (syn. n.). A. asiatica does not belong to the subgenus Nobandrena but is probably related to A. formosa Morawitz, 1878 and A. combusta Morawitz, 1876. Nomenclatural Actsasiatica Friese, 1921 (Andrena), Lectotyp

Ocean Acidification at High Latitudes: Potential Effects on Functioning of the Antarctic Bivalve Laternula elliptica

Ocean acidification is a well recognised threat to marine ecosystems. High latitude regions are predicted to be particularly affected due to cold waters and naturally low carbonate saturation levels. This is of concern for organisms utilising calcium carbonate (CaCO3) to generate shells or skeletons. Studies of potential effects of future levels of pCO2 on high latitude calcifiers are at present limited, and there is little understanding of their potential to acclimate to these changes. We describe a laboratory experiment to compare physiological and metabolic responses of a key benthic bivalve, Laternula elliptica, at pCO2 levels of their natural environment (430 µatm, pH 7.99; based on field measurements) with those predicted for 2100 (735 µatm, pH 7.78) and glacial levels (187 µatm, pH 8.32). Adult L. elliptica basal metabolism (oxygen consumption rates) and heat shock protein HSP70 gene expression levels increased in response both to lowering and elevation of pH. Expression of chitin synthase (CHS), a key enzyme involved in synthesis of bivalve shells, was significantly up-regulated in individuals at pH 7.78, indicating L. elliptica were working harder to calcify in seawater undersaturated in aragonite (ΩAr = 0.71), the CaCO3 polymorph of which their shells are comprised. The different response variables were influenced by pH in differing ways, highlighting the importance of assessing a variety of factors to determine the likely impact of pH change. In combination, the results indicate a negative effect of ocean acidification on whole-organism functioning of L. elliptica over relatively short terms (weeks-months) that may be energetically difficult to maintain over longer time periods. Importantly, however, the observed changes in L. elliptica CHS gene expression provides evidence for biological control over the shell formation process, which may enable some degree of adaptation or acclimation to future ocean acidification scenarios