Rhodachlya madagascarensis gen. et sp. nov.: a distinct acrochaetioid represents a new order and family (Rhodachlyales ord. Nov., Rhodachlyaceae fam. Nov.) of the Florideophyceae (Rhodophyta)

The taxonomy of the Cladophoraceae, a large family of filamentous green algae, has been problematic for a long time due to morphological simplicity, parallel evolution, phenotypic plasticity, and unknown distribution ranges. Partial large subunit (LSU) rDNA sequences were generated for 362 isolates, and the analyses of a concatenated dataset consisting of unique LSU and small subunit (SSU) rDNA sequences of 95 specimens greatly clarified the phylogeny of the Cladophoraceae. The phylogenetic reconstructions showed that the three currently accepted genera Chaetomorpha, Cladophora, and Rhizoclonium are polyphyletic. The backbone of the phylogeny is robust and the relationships of the main lineages were inferred with high support, only the phylogenetic position of both Chaetomorpha melagonium and Cladophora rupestris could not be inferred unambiguously. There have been at least three independent switches between branched and unbranched morphologies within the Cladophoraceae. Freshwater environments have been colonized twice independently, namely by the freshwater Cladophora species as well as by several lineages of the Rhizoclonium riparium clade. In an effort to establish monophyletic genera, the genera Acrocladus and Willeella are resurrected and two new genera are described: Pseudorhizoclonium and Lurbica.

Section: Discussionmentioning

confidence: 99%

Molecular phylogeny of the Cladophoraceae (Cladophorales, Ulvophyceae), with the resurrection of Acrocladus Nägeli and Willeella Børgesen, and the description of Lurbica gen. nov. and Pseudorhizoclonium gen. nov.

Boedeker

Leliaert

Zuccarello

2016

“…This is especially evident in “simple” red algae (e.g., Bangia Nelson et al. 2005, Acrochaetium West et al. 2008, Bostrychia Zuccarello and West 2006).…”

Section: Discussionmentioning

confidence: 99%

Molecular Phylogeny of the Upright Erythropeltidales (Compsopogonophyceae, Rhodophyta): Multiple Cryptic Lineages of Erythrotrichia Carnea1

Zuccarello

Yoon

Kim

et al. 2011

Self Cite

The phylogeny of morphologically simple algae is problematic due to insufficient morphological characters to aid in distinguishing species and relationships. The problem is further compounded because multiple evolutionary lineages of morphologically similar species occur in most well-sampled biogeographic locations; therefore, location cannot be used as a proxy for species. The phylogeny of the upright members of the Erythropeltidales is partially clarified by combining molecular data, unialgal culture observations, and worldwide sampling. Our results show that there are several well-supported lineages within the Erythropeltidales with only two morphologically recognizable taxa at present. The first is the genus Porphyrostromium, with a well-developed basal crust, which includes two Erythrotrichia species (Porphyrostromium ligulatum comb. nov. and Porphyrostromium pulvinatum comb. nov.). The second is the branched species Erythrotrichia welwitschii (Rupr.) Batters. There are also six strongly supported Erythrotrichia carnea-like lineages. While not completely satisfactory, we propose that one lineage (lineage 2) with samples close to the type locality be designated as E. carnea with a specific isolate as an epitype. The lack of morphology to differentiate the other lineages leads to a taxonomy based solely on gene sequencing and molecular phylogeny, with rbcL sequences differentiating the lineages proposed. We hold off on proposing more species and genera until more data and samples can be gathered.

“…Defining genera based solely on molecular data is becoming more common, especially in morphologically simple algae (Nelson et al. 2005, West et al. 2008).…”

Section: Discussionmentioning

confidence: 99%

MOLECULAR PHYLOGENY OF THE CRUSTOSE ERYTHROPELTIDALES (COMPSOPOGONOPHYCEAE, RHODOPHYTA): NEW GENERAPSEUDOERYTHROCLADIAANDMADAGASCARIAAND THE EVOLUTION OF THE UPRIGHT HABIT

Zuccarello¹,

Kikuchi²,

West³

2010

Self Cite

The Erythropeltidales are a common group of small, mostly epiphytic, marine red algae. Morphologically, they can be divided into two main groups: species that are crustose and species that are upright. Being morphologically simple, generic boundaries and evolutionary trends are controversial or unknown. We focus our molecular phylogenetic analysis on members that are crustose using samples collected from around the world and placed in unialgal culture. Our data indicate that one upright genus, Porphyropsis, is closely related to crustose genera and that the upright habit evolved at least twice in the order. In addition, the genus Sahlingia is supported as distinct from Erythrocladia. Within samples identified as Erythrocladia, three groups are distinguished: Erythrocladia, composed of crustose aggregating filaments with pyrenoids; Pseudoerythrocladia gen. nov., crustose aggregating filaments without pyrenoids, a sister genus to Porphyropsis also without pyrenoids; and Madagascaria gen. nov., a sister genus to all other Erythropeltidales samples that is only subtly different from Erythrocladia. Within these genera, no clear morphological groups are evident, nor is the level of molecular diversity suggestive of multiple species. We suggest that described species, especially in the genus Erythrocladia, are just morphological variants, due to substrate or environmental variation, and further descriptions of these morphologically simple algae must incorporate molecular data and standardized culture conditions.