Hanicella moenia, gen. et sp. nov., a ribbon‐forming diatom (Bacillariophyta) with complex girdle bands, compared to Microtabella interrupta and Rhabdonema cf. adriaticum: implications for Striatellales, Rhabdonematales, and Grammatophoraceae, fam. nov. Issue 5 (3rd September 2014)

• Record Type: Journal Article
• Authors: Lobban, Christopher S.; Ashworth, Matt P.; De Clerck, O.
• Is Part Of: Journal of phycology. Volume 50:Issue 5(2014:Oct.)
• Page Start: 860
• Page End: 884
• Publication Date: 2014-09-03
• Subjects: Algae -- Periodicals; 579.8
• DOI: 10.1111/jpy.12217
• Languages: English
• ISSNs: 0022-3646

Abstract

<abstract abstract-type="main" id="jpy12217-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Tropical benthic diatoms are poorly known but constitute a rich resource for studies of diatom morphology and phylogeny. A remarkable tabellarioid ribbon‐forming diatom with a very distinctive pattern of plastid distribution and unique valve and girdle band characters is described from Guam (Mariana Islands) as a new genus and species, <italic>Hanicella moenia</italic>. We were able to study the ultrastructure and ontogeny of the girdle bands, to compare several other genera in the Striatellales and the Rhabdonematales with numerous septate copulae and hyaline, nonseptate pleurae, and to evaluate their phylogenetic relationships. The last‐formed two copulae of <italic>Microtabella interrupta</italic> have distended septa, the last interlocking with the other via a transverse ridge between two unique "ligules." The fourth pleura of <italic>Hanicella</italic> is a delicate, fimbriate band. Views of developing copulae of <italic>H. moenia</italic> indicated that the septum was formed by ingrowth from the sides rather than from the apex; this blurs the distinction between septate and scalariform valvocopulae. Phylogenetic results (i) confirmed that the Striatellales and Striatellaceae, consisting of <italic>Striatella</italic> and <italic>Pseudostriatella</italic>, are unrelated to clades containing <italic>Hyalosira</italic>, <italic> Microtabella</italic>, <italic> Hanicella</italic>, and <italic>Rhabdonema</italic>; and (ii) showed that the fRhabdonemataceae is close to, but separate from, the strongly supported <italic>Hanicella</italic>/<italic>Microtabella</italic>/<italic>Grammatophora</italic> clade, for which we propose Grammatophoraceae fam. nov. Formal genus and species descriptions of <italic>H. moenia</italic> are given and we also propose to restore <italic>Hyalosira interrupta</italic> to <italic>Microtabella</italic> with an emended genus description.</p> </abstract>