Cocconeis Ehrenberg taxa (Bacillariophyta) with a marginal row of simple processes: relationship with the valvocopula system and distinctive features of related taxa - Archive ouverte HAL Access content directly
Journal Articles Fottea (Praha) Year : 2015

Cocconeis Ehrenberg taxa (Bacillariophyta) with a marginal row of simple processes: relationship with the valvocopula system and distinctive features of related taxa

(1, 2) , (3) , (4) , (5)
1
2
3
4
5

Abstract

As first observed on a group of taxa related to Cocconeis peltoides Hustedt, several other Cocconeis eHRenbeRG (Bacillariophyta) taxa possess a row of minute marginal pores on the external side of their sternum valve (SV) connected to small and simple internal portules, or processes. These processes are often located in continuity with the striae, but can also be slightly shifted or distant from the distal areola of the striae. The row of pores is often, but not always, externally separated from the stria by a crista marginalis. Within Cocconeis, and possibly all raphid diatoms, these processes seem unique and restricted to a few taxa. A list is presented of the taxa pertaining (or close) to Cocconeis that are actually known to share these micro–structures. In addition, the morphological variability of the processes is described in detail and a morphological comparison of the taxa is provided. The characteristic features of taxa showing a row of SV processes permit the tentative definition of several morphological groups. It is difficult to prove the taxonomic affiliation of these taxa and demonstrate or refute that these processes are ancestral characters. Some of these taxa are rare and restricted to low latitudes (e.g., tropical taxa) while others are frequent and ubiquitous. Abbreviations: (LM) light microscope, (SEM) scanning electron microscope, (RV) raphe valve, (SV) sternum valve, (RVVC) raphe valve valvocopula, (SVVC) sternum valve valvocopula
Fichier principal
Vignette du fichier
fottea_fot-201502-0003.pdf (6.82 Mo) Télécharger le fichier
Origin : Publication funded by an institution
Loading...

Dates and versions

hal-01212883 , version 1 (07-10-2015)

Identifiers

Cite

Catherine Riaux-Gobin, Andrzej Witkowski, Pierre Compère, Oscar E. Romero. Cocconeis Ehrenberg taxa (Bacillariophyta) with a marginal row of simple processes: relationship with the valvocopula system and distinctive features of related taxa. Fottea (Praha), 2015, 15 (2), pp.139-154. ⟨10.5507/fot.2015.015⟩. ⟨hal-01212883⟩
311 View
312 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More