Diatoms as dandelions: convergent evolution in the reproductive biology of small Nitzschia species (Bacillariophyta) and its possible taxonomic consequences
View/Open
This document contains embargoed files until 2025-03-01
Publication date
2024-03-01ISSN
0031-8884
Abstract
Nitzschia soratensis and N. inconspicua are two small diatoms that are extremely similar in the light microscope though separable in subtle aspects of valve and girdle ultrastructure. They are not closely related in molecular phylogenies and differ in their ecological preferences, though they sometimes co-occur in the same communities. To test further their functional equivalence, we investigated the reproductive biology of N. soratensis, for comparison with a previously published account of N. inconspicua. Both species are automictic, lacking pairing between gametangia and gamete exchange. Nuclear staining shows the presence of two nuclei in some auxospores of N. soratensis, which are smaller than the nuclei of vegetative cells and appear to be haploid, indicating prior meiosis. These auxospores, surrounded by incunabula containing tangles of silica strips, give rise to uninucleate initial cells 18–21 µm long. Frequently, however, small N. soratensis cells produce two spherical ‘pseudogametes’, some of which abort while others expand and form initial valves shorter than those produced by binucleate auxospores (maximum length 14.5 µm). Similar uniparental auxosporulation, with silica strip formation, occurs in N. aff. hantzschiana, N. acidoclinata, N. fonticola and N. angustata, which are close relatives of N. soratensis according to morphological and/or molecular evidence. This group and the N. inconspicua complex may be the diatom equivalents of apomictic angiosperms, e.g. dandelions, and likely contain a multitude of microspecies.
Document Type
Article
Document version
Accepted version
Language
English
Subject (CDU)
574 - General ecology and biodiversity
Pages
41
Publisher
Taylor & Francis Group
Is part of
Phycologia
Citation
Mann, David G., and Rosa Trobajo. 2024. “Diatoms as Dandelions: Convergent Evolution in the Reproductive Biology of Small Nitzschia Species (Bacillariophyta) and Its Possible Taxonomic Consequences.” Phycologia, 63(2):179-195. https://doi.org/10.1080/00318884.2024.2309855.
Program
Aigües Marines i Continentals
This item appears in the following Collection(s)
- ARTICLES CIENTÍFICS [2635]
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc-nd/4.0/