Morphology and systematics of Calliblepharis hypneoides, sp. nov. (Cystocloniaceae, Rhodophyta) from the Atlantic Iberian Peninsula

Abstract

Calliblepharis hypneoides Díaz-Tapia, Bárbara & Hommersand, sp. nov., is described based on plants collected in sand-covered rocks from southern France to Portugal. Calliblepharis hypneoides is distinguished by a terete thallus, forming an extensive basal system of entangled prostrate axes that bear few irregularly branched upright axes, an inner structure consisting of a central axial filament surrounded by 5-7 filaments of elongated cells, a continuous outer cortex, spermatangial parent cells transformed from outer cortical cells and bearing spermatangial filaments three or four cells long, a single gonimoblast initial cut off from the inner side of the auxiliary cell, with the young carposporophyte consisting of a central reticulate network of interconnected cells linked inwardly to a cluster of basal nutritive filaments and forming gonimoblasts outwardly that bear chains of carposporangia in nonostiolate cystocarps arising on main axes and branches, and tetrasporangia terminal in sori on ultimate branchlets. These features are characteristic of Calliblepharis and molecular analyses confirm this relationship. In all phylogenetic analyses of cox1, rbcL and SSU sequences, C. hypneoides was consistently distinct from congeners. In both rbcL and SSU trees, its sister relationship to other species was unresolved, probably due to missing species or the exclusion of undescribed species. This is the first report on the systematics of Calliblepharis using three molecular markers.

Neoharaldiophyllum, a new genus of Delesseriaceae (Rhodophyta) based on carposporophyte development and molecular data

“…Several recent taxonomic studies of molecular phylogeny with attention paid to female morphology indicated that the developmental patterns of carposporophytes are a proper character for defining boundaries at the generic level in the orders Gigartinales and Halymeniales, as well as Ceramiales (Lin et al 2002, 2012, Díaz-Tapia et al 2013, Gargiulo et al 2013). In our phylogenetic trees (Figures 55 and 56), the original concept of the Myriogramme-group by Kylin (1924) is first divided by procarp shape (i.e.…”

Molecular analyses and reproductive structure to verify the generic relationships of Hypnea and Calliblepharis (Cystocloniaceae, Gigartinales), with proposal of C. saidana comb. nov.

“…Section samples were stained with 1% aniline blue, acidified with 1% HCl and mounted in a 40% corn syrup solution. We also treated with Wittmann's (1965) aceto-iron-hematoxylin-chloral hydrate, and mounted in 50% Hoyer's mounting medium (Lin et Calderon and Boo 2016, Won et al 2016, Yang and Kim 2016, reproductive structures have remained important diagnostic characteristics for differentiating many genera in the order Gigartinales (Hommersand et al 1999, Díaz-Tapia et al 2013. For instance, Hypnea and Calliblepharis can be readily distinguished each other by female reproductive structures even if they share many vegetative features in common.…”

“…For example, current classification of H. saidana lack the consideration of reproductive structure, according to Shin and Boo (1994) which is essential for proper reassessment due to its similarity to Calliblepharis in terms of vegetative features, i.e., complanate thalli, dispersed surface cells, and numerous pit connections between medullary cells. In addition, recently described taxa, Calliblepharis hypneoides Díaz-Tapia, Bárbara & Hommersand and C. psammophilus D'Archino & W. A. Nelson, were assigned to Calliblepharis based on observations of the female structures even though they superficially resembled the species of Hypnea (Díaz-Tapia et al 2013, D'Archino et al 2015.…”

“…Although the inclusion of molecular data has become commonplace in modern taxonomy (Yang et al 2015, These considerations clearly reveal the possibility that current taxonomy of H. saidana based on vegetative morphology could be mistaken as Díaz-Tapia et al (2013) mentioned, although some red algal species can be assigned to Hypnea based on morphology, they could be assigned equally well to Calliblepharis. This implies that phylogeny regarding species of these two genera requires highly refined morphological characterization and molecular analysis using diverse species enough to allow inter-genera comparison within the order Gigartinales.…”

<italic>Alsidium oliveiranum</italic> sp. nov. (Rhodomelaceae, Rhodophyta), an overlooked species from the southwestern Atlantic based on morphology and DNA sequence data

“…Intertidal sand-covered rocks are other common, more accessible, but often poorly explored habitat. The presence of sediments in intertidal rocks negatively affects many benthic organisms, and sand-covered rocks host a particular algal assemblage (Airoldi 2003, Díaz-Tapia et al 2013a in which several new red algal species have been recently described (Díaz-Tapia and , Díaz-Tapia et al 2013b, D´Archino et al 2015. During our surveys of marine red algae in this habitat along the coasts of Espírito Santo and Rio de Janeiro (southeastern Brazil), we found abundant populations of a rhodomelacean species consisting of large plants (up to 25 cm in length) with seven pericentral cells and a dense cortication from close to the apices.…”