Voigt Oliver, Ruthensteiner Bernhard, Leiva Laura, Fradusco Benedetta, WÖrheide Gert
Department of Earth and Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany.
Zootaxa. 2018 Feb 20;4382(1):147-158. doi: 10.11646/zootaxa.4382.1.5.
The diversity and phylogenetic relationships of calcareous sponges are still not completely understood. Recent integrative approaches combined analyses of DNA and morphological observations. Such studies resulted in severe taxonomic revisions within the subclass Calcinea and provided the foundation for a phylogenetically meaningful classification. However, several genera are missing from DNA phylogenies and their relationship to other Calcinea remain uncertain. One of these genera is Leuclathrina (family Leucaltidae). We here describe a new species from the Maldives, Leuclathrina translucida sp. nov., which is only the second species of the genus. Like the type species Leuclathrina asconoides, the new species has a leuconoid aquiferous system and lacks a specialized choanoskeleton. Phylogenetic analyses of the partial 28S ribosomal RNA gene revealed that L. translucida sp. nov. is most closely related to a clade containing the exclusively asconoid genera Ascandra, Levinella and Soleneiscus, and to a clade of the likewise asconoid genus Ernstia. No close relationship exists to other members of the polyphyletic family Leucaltidae, or to any other leuconoid Calcinea. Our results suggest that the leuconoid aquiferous system of Leuclathrina evolved independently from that of other calcineans and that the family assignment of the genus has to be reconsidered. Because the latter requires a more comprehensive family level revision among many genera of Calcinea, we propose to formally retain the genus in Leucaltidae for the time being.
钙质海绵的多样性和系统发育关系仍未完全明晰。近期的综合研究方法结合了DNA分析和形态学观察。这类研究导致了钙质海绵亚纲内的严重分类修订，并为具有系统发育意义的分类奠定了基础。然而，DNA系统发育树中缺少几个属，它们与其他钙质海绵亚纲属的关系仍不明确。其中一个属是白枝海绵属（白枝海绵科）。我们在此描述一种来自马尔代夫的新物种——半透明白枝海绵（Leuclathrina translucida sp. nov.），它是该属的第二个物种。与模式种阿斯康白枝海绵一样，新物种具有复沟型水管系统，且缺乏特化的领细胞层骨骼。对部分28S核糖体RNA基因的系统发育分析表明，半透明白枝海绵与一个包含仅具单沟型的阿斯康属、列文海绵属和索勒尼斯海绵属的分支，以及同样具单沟型的恩氏海绵属的分支关系最为密切。与多系的白枝海绵科的其他成员或任何其他复沟型钙质海绵亚纲成员均无密切关系。我们的结果表明，白枝海绵的复沟型水管系统是独立于其他钙质海绵进化而来的，该属的科归属需要重新考虑。由于后者需要对钙质海绵亚纲的许多属进行更全面的科级修订，我们建议暂时正式将该属保留在白枝海绵科中。
