Diversity ofChroothece(Rhodophyta, Stylonematales) including two new species

Abstract

Chroothece has been reported from a range of freshwater environments, including streams, shallow ponds, trickling water on cliffs and moist soils, mostly in Europe and North America. The identification of genera and species by morphology is difficult because of overlaps in critical characters. To help clarify diversity within the genus, samples from Spain and from other regions (UK and Guam, western Pacific) were compared. Ecological and morphological data from field and cultured material were correlated with molecular data (rbcL gene sequences) that differentiate two new species: Chroothece thermalis I. Chapuis, P. Sánchez, M. Aboal & O. Necchi Jr., sp. nov. in a thermal spring and Chroothece lobata M. Aboal, B. A. Whitton, I. Chapuis, P. Sánchez & O. Necchi Jr., sp. nov. in a semi-arid stream. The results suggest recognition of four species, C. thermalis, C. lobata, C. richteriana Hansgirg and C. rupestris Hansgirg, from Spain. Morphology and ecology are useful to help distinguish these species, but the genus needs further study for possible cryptic diversity.

Confocal Microscopy in Ecophysiological Studies of Algae: A Door to Understanding Autofluorescence in Red Algae

“…Morphologically, the cells are fairly similar to other species of the genus, with the only differences being the cell size, the ability to form persistent stalks and hemispheric colonies and the habitat (Aboal et al, 2017). No morphological or structural changes were observed in any of the experiments.…”

“…Red algae owe their name to the presence of phycoerythrin (PE), the red-colored phycobiliprotein, although not all red algae are red in color; some of the structurally simple genera are bluish (Eloranta et al, 2011;Aboal et al, 2017). This change in color reflects the dominance of phycocyanins (PCs) and a relatively lower proportion of PE as an adaptation to environmental conditions.…”

“…The Chroothece genus currently contains seven species that live in small creeks and rivers, cliffs, caves, or thermal waters (Aboal et al, 2017). The effect on Chroothece richteriana (later confirmed as C. lobata) of some variables related to climate change was studied recently by Gonzalez-Silvera et al (2017) who analyzed the influence of salinity, temperature, nitrogen, light intensity, and ultraviolet (UV) radiation on fatty acid composition and mycosporin-like amino acids on field-collected colonies.…”

“…The effect on Chroothece richteriana (later confirmed as C. lobata) of some variables related to climate change was studied recently by Gonzalez-Silvera et al (2017) who analyzed the influence of salinity, temperature, nitrogen, light intensity, and ultraviolet (UV) radiation on fatty acid composition and mycosporin-like amino acids on field-collected colonies. Chroothece mobilis was reported in a range of different conditions in subaerial habitats (Hindak & Hindakova, 2015), cold waters (Blinn & Prescott, 1976), hot springs (Pentecost, 2011), and caves (Aboal et al, 2017). Although this species was originally described from a salt marsh (Pascher & Petrová, 1931), there are no data on their optimal environmental requirements.…”

Exploring the Diversity of Red Microalgae for Exopolysaccharide Production

“…C. richteriana cells are described as ellipsoid or cylindrical (~12 µm width and 15 µm length) surrounded by a mucilaginous envelope that may grow unilaterally. This can develop into a stalk, connected with the basal part of the sheath surrounding cells [18,19]. Depending on the culture conditions, C. richteriana cells can develop as free-living cells and colonies or under pseudofilamentous form [18].…”