The crustose red algal genus Peyssonnelia (Peyssonneliales, Rhodophyta) in the Azores : from five to one species

The family Peyssonneliaceae comprises a worldwide group of non-calcified to calcified, crust-forming red algae of great ecological significance. Of the genera currently recognized in the family, Peyssonnelia has been widely considered to contain the largest number of species, with five members reported for the Azores. Using rbcL as a molecular marker, we here report on the taxonomic identity of recent collections of Peyssonneliaceae from the Azorean islands of São Miguel, Graciosa and Pico, and compare those specimens in a worldwide context. Only a single Peyssonnelia species, P. squamaria, is confirmed for the Azorean archipelago, with three different haplotypes. Although the populations in the Azores are genetically different from those occurring in the Mediterranean, this separation appears to be relatively recent

The Critical Importance of Rhodoliths in the Life Cycle Completion of Both Macro- and Microalgae, and as Holobionts for the Establishment and Maintenance of Marine Biodiversity

Rhodoliths are the main hard substrata for the attachment of benthic macroalgae in the NW Gulf of Mexico rubble habitats that are associated with salt domes, unique deep bank habitats at ~50–90 m depth on the continental shelf offshore Louisiana and Texas. With the advent of additional sequencing technologies, methodologies for biodiversity assessments are now rapidly shifting to DNA metabarcoding, i.e., High Throughput Sequencing (HTS) of environmental DNA mixtures with standardized molecular markers, such as 16S V4, for rapid, cost-effective biodiversity measurement. We newly tested 16S V4 metabarcoding on endolithic portions of mesophtic rhodoliths exhibiting low phototroph colonization that revealed a hidden, cryptic algal diversity targeting spores, propagules, and unsuspected life history stages. We explored cryo-SEM as a potentially more informative method than regular SEM to minimize artifacts of sample preparation in the study of endolithic cell inclusions which brought to light a suite of microalgal stages. We were able to differentiate floridean starch from cellular inclusions. We associated the effect of anatomical growth pattern on presence or absence of cellular inclusions in biogenic rhodoliths. Analyses of combined 16S V4 metabarcodes and 16S Sanger sequences of two red algal orders, the Halymeniales and Bonnemaisoniales, increased the established record of diversity in the region. We view rhodoliths as marine biodiversity hotspots that may function as seedbanks, temporary reservoirs for life history stages of ecologically important eukaryotic microalgae, and macroalgae or as refugia for ecosystem resilience following environmental stress

New Insights into the Rhodolith Microenvironment, With a Focus on the Gulf of Mexico

SEM observations have revealed unknown and previously undetected stages of the bloom-forming dinoflagellate Prorocentrum growing inside calcium carbonate-encrusted perithallial cells of the rhodolith-forming Lithothamnion sp. (Hapalidiaceae, Hapalidiales, Rhodophyta) in the NW Gulf of Mexico. Roundish structures inside the coralline cells were clustered together, surrounded by a thin membrane. Organized blebs, projections of the cytoplasm into the plasma membrane, as well as a suite of varying extracellular ornamentation patterns, were observed. Openings on the surface of some of the structures looked like characteristic thecal pores found in thecal plates of some dinoflagellates. DNA was extracted from inside the rhodolith and sequenced using dinoflagellate-specific cob1-primers. When blasting the resulting DNA sequences, it proved to be an exact match for Prorocentrum lima. Cells were isolated from inside the rhodoliths and cultured, revealing the presence of another set of endolithic life stages identified as Haptophyta (Prymnesiophyta), confirmed by single cell 18S rDNA sequencing. This research illustrates and illuminates newly found benthic life history stages of two ecologically important taxa of primary producers that also cause harmful algal blooms, such as the formation of red tides, fish kills, or shellfish poisoning events in the Gulf of Mexico

NEW PENNSYLVANIA COUNTY OCCURRENCES FOR BELLIS PERENNIS, HIBISCUS MOSCHEUTOS, LAMIUM MACULATUM, AND ROBINIA HISPIDA

Volume: 6Start Page: 707End Page: 71

Two new species of Caloglossa (Delesseriaceae, Rhodophyta) from the Americas, C. confusa and C. fluviatilis spp. nov.

Although the systematics of Caloglossa has been intensely investigated, the species diversity of the genus is not yet fully understood. Comparative chloroplast-encoded rbcL and nuclear LSU rDNA sequence analyses, combined with morphological observations, reveal new records and two new species for the Americas. The species, previously identified as Caloglossa monosticha from the western Atlantic, is newly described as C. confusa sp. nov. It differs from Pacific Ocean C. monosticha primarily by its strongly constricted thallus nodes, and the sequence data presented here show that it is most closely allied with other taxa of the C. continua species complex, but its relationship with these taxa is not fully resolved. The freshwater C. fluviatilis sp. nov.from the Panama Canal is characterised by thalli arranged in tufts, adventitious branching, strong constrictions at the thallus nodes and lanceolate blades. Caloglossa fluviatilis forms a monophyletic group along with the species having only adventitious secondary branching. A dichotomous key highlights the diagnostic vegetative characters for separating the nine species of Caloglossa occurring in the Americas