Bernhard Ruthensteiner

Five years ago, the Panamanian evolutionary lineage (EL) C12 was uncovered along with four other ELs in an integrative phylogenetic investigation of worldwide Carychiidae. Since EL C12 lacked shell material post-molecular analysis to serve as a museum voucher, it remained undescribed. Now, after recent collection efforts of C12 and the congener, Carychium zarzaae Jochum & Weigand, 2017 at their original Panamanian sites, C12 is morphologically described and formally assigned the name, Carychium panamaense Jochum, sp. n. In sync with recent taxonomic treatment of the genus, computed tomography (CT) is used in this work to differentiate shells of C. panamaense sp. n. from geographically-proximal, Caribbean, North and Central American congeners. Recent material of topotypic Carychium jardineanum (Chitty, 1853) and undamaged C. zarzaae were additionally CT-scanned and assessed in the comparative analyses.

This study provides a detailed description of the cephalic sensory organ (CSO) of four species of the cephalaspid genus Haminoea (Opisthobranchia, Gastropoda), based on light and electron microscopical investigations of complete serially sectioned larvae. The organ, which is present in all species investigated, exhibits the characteristic elements of gastropod CSOs: Two ciliary tuft cells; four to six ampullary cells showing intracellular lumina filled with bundles of tightly packed cilia; three para-ampullary cells interspersed medially and positioned laterally; a modified thickened microvillar border. A ciliary tuft is present in the planktotrophic developer Haminoea cymbalum, H. exigua and the intracapsular developer H. navicula, while it is lacking in the poecilogonous developer H. callidegenita. The number of ampullary cells ranges from 4 (H. cymbalum, H. exigua) to 6 (H. navicula, H. callidegenita). In general no clear correlation of development mode (e.g. planktotrophic vs. intracapsular) and organization of the organ can be found. Most structures, except ciliary tufts and number of ampullary cells, are very similar among the investigated species. The CSO cells of Haminoea are compared with those of other gastropods in the literature. The organ as a whole as well as its cellular components of Haminoea can clearly be homologized with such structures in other gastropods. The CSO's relationship to apical organs with regard to homology and the function is discussed.

The apical area of larvae of four primitive pulmonate species was investigated by means of serial ultrathin and light microscope sections. Cephalic sensory organs (CSOs) were found in the larvae of Onchidium cf. branchiferum (Onchidiidae) and Laemodonta octanfracta (Ellobiidae), while no trace of the organ was present in the larvae of Ovatella myosotis (Ellobiidae) or Williamia radiata (Siphonariidae). TEM investigation revealed very similar CSOs in O. cf. branchiferum and L. octanfracta, with characteristic putative sensory cell types: ampullary cells with an internal ampulla containing densely packed cilia, para-ampullary cells with external cilia parallel to the surface, and ciliary tuft cells, bearing short ciliary tufts. The epithelium covering the organ has a thick microvillar border with microvilli laterally bearing a pair of electron-dense accumulations and a glycocalyx with interspersed flat plaque-like elements. While homologues of all major elements of the CSO can be found in other gastropod taxa, for example caenogastropods and opisthobranchs, the homology of the ampullary cell with similar cells in nongastropods appears unlikely. The CSO of L. octanfracta is associated with an additional structure, an epithelial external protrusion, lying ventral to the CSO. The absence of the organ in W. radiata weakens hypotheses on the organ's function of examining settlement conditions and velar control.

... Andreas Wanninger,“ Bernhard Ruthensteiner, and Gcrhard Haszprunar ... belonged to already torted gastropod mol-luscs, or to yet untorted animals and possible gastro-pod ancestors or members of Paleozoic gastropod sister clades (Wenz 1940; Knight 1947; Rollins & Bat ...

With the latest release of the S2PLOT graphics library, embedding interactive, 3-dimensional (3-d) scientific figures in Adobe Portable Document Format (PDF) files is simple, and can be accomplished without commercial software. In this paper, we motivate the need for embedding 3-d figures in scholarly articles. We explain how 3-d figures can be created using the S2PLOT graphics library, exported to Product Representation Compact (PRC) format, and included as fully interactive, 3-d figures in PDF files using the movie15 LaTeX package. We present new examples of 3-d PDF figures, explain how they have been made, validate them, and comment on their advantages over traditional, static 2-dimensional (2-d) figures. With the judicious use of 3-d rather than 2-d figures, scientists can now publish, share and archive more useful, flexible and faithful representations of their study outcomes. The article you are reading does not have embedded 3-d figures. The full paper, with embedded 3-d figu...