Document of bibliographic reference 348212

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

Torgania coronata gen. et sp. nov.: a new needle-shaped genus, with comments on the raphe system as a diagnostic character in Eunotiales (Ochrophyta, Bacillariophyceae)

Abstract

The diatom Torgania coronata gen. et sp. nov. from the Brazilian Amazon is described based on light and scanning electron microscopy. Members of this genus have the raphe system entirely located on the valve surface, needle-shaped, isopolar valves with one rimoportula at each apex, and isovalvar frustules. Under the light microscope, members of Torgania can be confused with some species of Fragilaria, such as F. tenera, due to the aciculiform valve outline and inconspicuous striae. We consider that the presence of the raphe on the valve surface prevents Torgania from being placed in the Eunotiaceae. We also consider that Torgania’s placement within Peroniaceae is inadequate due to its isovalvar frustules and isopolar valves. Therefore, we did not include Torgania in this family either. Fragilaria braunii was recently transferred to the genus Peronia due to the discovery of a vestigial raphe system, along with the presence of rimoportulae, and characteristics of the girdle elements. However, in our opinion, this species better fits in the newly proposed Torgania than in Peronia and we therefore propose the new combination, Torgania braunii comb. nov. The characteristics found in the newly proposed genus indicate that the traditional dichotomy between Eunotiaceae/Peroniaceae is no longer appropriate. We argue that the eunotioid clade should be defined mainly by the raphe system non-integrated with the sternum, and that terms such as ‘simple’ or ‘short’ in reference to the raphe should be avoided. In addition, we provide a morphological key for the identification of Eunotiales genera.

WebOfScience code

https://www.webofscience.com/wos/woscc/full-record/WOS:000592029200001

Bibliographic citation

Canani, L.G.C.; Talgatti, D.M.; Melo, S. (2021). Torgania coronata gen. et sp. nov.: a new needle-shaped genus, with comments on the raphe system as a diagnostic character in Eunotiales (Ochrophyta, Bacillariophyceae). Eur. J. Phycol. 56(3): 289-300. https://dx.doi.org/10.1080/09670262.2020.1824018

Topic

Marine

Is peer reviewed

true