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Polyunsaturated fatty acids are essential biomolecules to human health since their consumption is associated with decreased risk of cardiovascular, inflammatory and cancer diseases, for instance. Despite largely unexplored, sub-Antarctic macroalgae have a considerable nutraceutical potential since this region is known for its harsh environmental conditions, which forces macroalgae to produce secondary metabolites. Therefore, the aims of this work were to determine the fatty acid profile of Ulva sp., Lessonia flavicans Bory and Pyropia columbina (Montagne) W.A. Nelson collected from different collection sites in the Magellan region. Results showed that macroalgae were comprised of 18 to 24 fatty acids with generally a predominance of saturated fatty acids (SFAs) than unsaturated fatty acids. SFAs comprehended 34.40 ± 0.61 mol% of Lessonia flavicans while Pyropia columbina had 69.06 ± 0.77 mol% mainly in the form of palmitic acid. Polyunsaturated fatty acids were found in concentrations ranging from 15.80 ± 0.56 mol% in Pyropia columbina to 54.93 ± 0.15 in Lessonia flavicans. The nutraceutical potential of these macroalgae was observed as the samples had a ∑n3/∑n6 ratio above the indicated by the World Health Organization. Principal Component Analysis showed that the fatty acid profile is characteristic of each macroalgae being a biochemical marker for the identification of the organisms. Therefore, sub-Antarctic macroalgae comprise a promising renewable source of essential fatty acids, mainly as n3, that are essential to the maintenance of human health.

This study aimed to analyze the cold stress effects (in terms of hematology, energy reserves, and oxidative stress) in Piaractus mesopotamicus (pacú) and their mitigation by a Pyropia columbina red seaweed-supplemented diet. For this purpose, juvenile fish were fed with a control (CD) or a red seaweed-supplemented diet (RD) for 60 days, and then, the animals were exposed to a low temperature (14 °C) and a control temperature (24 °C) for 24 h. The cold shock generated an increase of hemoglobin levels in fish fed with both diets. In CD-fed fish, plasmatic triglycerides, cholesterol, and hepatic glycogen decreased after the thermal shock; meanwhile, the animals fed with RD showed decreased hepatic proteins, but increased cholesterol and hepatic glycogen. Regarding oxidative stress, antioxidant enzymes augmented their activity in the liver, intestine, and gills; meanwhile, lipid oxidative damage was observed in the liver and intestine of fish exposed to 14 °C and fed with both diets. Pacú was sensitive to cold shock, but no mitigation effects were observed in fish fed with the supplemented diet. Further research should target higher concentrations of P. columbina in supplemented diets to take advantage of this valuable resource.

The aim was to evaluate the effects of diet supplementation with red seaweed Pyropia columbina or β-carotene on the intestinal microbiota of juvenile Pacu (Piaractus mesopotamicus). Three hundred and fifteen fish (body weight 12.4 ± 2.8 g) were stocked in nine 300-L tanks with 35 fishes per tank and fed for 62 days with a basal feed (BG) or the same feed added with P. columbina (35 g kg−1) (AG) or supplemented with β-carotene (225 g kg−1) (β-CG). From fecal samples of three fishes slaughtered per group at 20th, 41th, and 62th days, plate counts of bacterial populations (enterobacteria, lactic acid bacteria—LAB, total aerobes, and psychrotrophs) and DGGE were made. Enterobacteria counts were lower in AG-group than the other groups throughout the experience (p = 0.016). LAB/enterobacteria ratio was greater in fishes supplemented with AG on 20th day, showing a greater amount of beneficial bacteria than non-beneficial ones. DGGE profiles resulting from the microbiota of β-CG at 62th day were clustered and separated from the rest of the profiles with a difference of 91%. Margalef richness (p = 0.049) and Shannon diversity index (p = 0.044) were lower in β-CG than in AG at 62th day. Taxonomic characterization showed the presence of three phylum: Bacteroidetes, Firmicutes, and Fusobacteria. This is the first study in which the microbiota of juvenile Pacu fed with biofunctional diets was evaluated. Future interventions that modify the bacterial ecosystem could improve the productive performance and ensure the safety of the pacu meat intended for consumption.

The effects of wall hydrocolloids on delivery and bioaccessibility of encapsulated brewers’ spent grain ACE-I inhibitory peptides after simulated gastrointestinal digestion were assessed. Microencapsulation of peptides was carried out by spray drying using locust bean gum, P. columbina phycocolloids, or its mixtures as wall materials. Microcapsules presented round external surfaces with some concavities, negative surface charge and encapsulation efficiencies higher than 90%. The incorporation of phycocolloids to formulations increased the encapsulation efficiency, negative surface charge and resistance against digestive enzymes of microcapsules. Encapsulated peptides with P. columbina phycocolloids showed lower IC50 value of ACE-I inhibition than un-encapsulated peptides (2.4 ± 0.2 vs. 7.2 ± 0.3 mg mL−1 protein), but higher than that obtained for hydrolysate (1.5 ± 0.2 mg mL−1 protein), indicating a 75% protection of bioactivity. Electrostatic and hydrophobic interactions between P. columbina phycocolloids and brewers’ spent grain peptides could be implicated in the protection of peptides during gastrointestinal digestion. Fil: Cian, Raúl Esteban. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Salgado, Pablo Rodrigo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Mauri, Adriana Noemi. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina Fil: Drago, Silvina Rosa. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

The aim of this study was to evaluate the antioxidant effect of red seaweed Pyropia columbina on juvenile Pacú (Piaractus mesopotamicus). Two hundred and ten (n = 210) fish were fed for 90 days with a control extruded feed (CEF) or the same feed added with P. columbina (35 g kg−1) (PcEF). No significant difference in final bodyweight, specific growth rate, condition factor, and liver somatic index was detected between dietary treatments (p > 0.05). Fish fed with PcEF showed lower lipid peroxidation (28.2 ± 2.9 vs. 39.4 ± 3.7 mmol malondialdehyde mg−1 protein) and superoxide dismutase (23.3 ± 2.3 vs. 37.7 ± 3.0 U mg−1 protein) and reduced SOD/CAT ratio (5.5 ± 0.3 vs. 8.1 ± 0.7) in intestine than those fed with CEF (p < 0.05). These results also were observed in liver and white muscle, indicating a systemic effect. No difference in glutathione S-transferase and catalase (CAT) activity in intestine, liver, and white muscle was detected between dietary treatments (p > 0.05). PcEF showed higher hemoglobin (7.5 ± 0.4 vs. 6.6 ± 0.3 g 100 mL−1) and mean corpuscular hemoglobin concentration (18.4 ± 1.8 vs. 25.7 ± 2.7%) than those fed with CEF diet (p < 0.05). Beneficial effects on lipid metabolism were observed in fish fed with PcEF respect to control diet. Pyropia columbina could be used as a natural antioxidant ingredient in fish feeding contributing a better nutritional status of cultured fish. Fil: Cian, Raúl Esteban. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Bacchetta, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Rossi, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Cazenave, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Drago, Silvina Rosa. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

Pharmacotherapy has long been used to control viral diseases. However, its success is questionable because its use can negatively impact environmental and human health. An alternative solution is the use of functional foods and diets containing natural products, which tend to be more biodegradable than synthetic molecules and are less likely to generate resistance. Seaweed contains biologically active macronutrients and minerals that offer a natural alternative to synthetic molecules. Red seaweeds, in particular, are a rich source of anti-viral compounds. This study aimed to evaluate the effect of two edible red seaweeds, Pyropia columbina and Gracilaria chilensis cryo concentrates (RSCC), on the gene transcription levels in leukocyte proteins involved in antiviral response (INFγ, Mx, interleukin-6, cathelicidin, and lysozyme). The RSCCs were fed to fish (Salmo salar L.) at concentrations of 0.1, 1, or 10 g kg−1 for 56 days, and blood samples were collected at 8 weeks. The transcription levels of key genes associated with the antiviral response were analyzed by qRT-PCR using leukocyte mRNA as template. The Mx transcript level was significantly decreased (p

In order to promote the use of sub-Antarctic macroalgae as food, three species of seaweeds, Macrocystis pyrifera, Pyropia columbina, and Durvillaea antarctica, were used as ingredients in a variety of dishes such as cochayuyo bread, cochayuyo hamburgers, cochayuyo fettuccine, huiro fritters, huiro breadsticks, and luche-parsley pesto. Subsequently, the nutritional value of each of the dishes was analyzed. The chemical composition, including carbohydrates, proteins, lipids, sodium, and the fatty acid (FA) content, was examined. In general, the prepared food varieties demonstrated low lipid contents (4.1 to 8.5% dry weight, dw), moderate concentrations of protein (6.9 to 12.7% dw), and highly variable contents of total dietary fiber (1.3 to 18.9% dw). The fatty acid patterns were different for all prepared dishes, and the FA profile exhibited a beneficial contribution of polyunsaturated fatty acids (PUFAs), with a preponderance of linoleic acid and α-linolenic. The chemical composition of the dishes was compared to that of similar and commonly consumed food like white bread, hamburgers, fettuccine made of dough enriched with eggs, fritters, breadsticks, and green pesto. The results suggest that macroalgae can be used as an ingredient in prepared food where they may contribute successfully to a more balanced diet and to maintain the organoleptic characteristics in commercially attractive prepared food like cochayuyo bread, cochayuyo hamburger, cochayuyo fettuccine, huiro breadsticks, and luche-parsley pesto.

Red macroalgae (Phylum Rhodophyta) are considered to be an important source of biologically active metabolites; their use as functional feed ingredients in fish diets can increase disease resistance and animal growth. Furthermore, red macroalgae can be cultured in a sustainable and environmentally friendly manner. We evaluate the potential antiviral activity against the infectious salmon anemia (ISA) virus of Chilean red macroalgae as a sustainable feed additive in the Atlantic salmon (Salmo salar) diet. Lyophilized Chilean red macroalgae concentrates were elaborated and added to a commercial diet. Diets were prepared with 0.1, 1.0, and 10.0 % of Gracilaria chilensis and Pyropia columbina separately, and 0.1 and 1.0 % of a mix of both species in a 1:1 ratio. The diets were fed to S. salar over a period of 2 months. We collected data on production parameters and blood samples. The serum and its constituents were challenged with the ISA virus in the presence of Atlantic salmon kidney cells and tested ex vivo for antiviral capacity using a plaque reduction neutralization assay. Fish fed a diet containing 10 % G. chilensis showed a significantly higher specific growth rate compared with fish fed the control diet. The feed conversion ratio was not significantly affected by treatments. Sera from fish fed the algae diets showed a significant increase in antiviral activity against the ISA virus compared with sera of fish fed the control diet that did not include red macroalgae. Diets including G. chilensis (1.0 and 10 %) exhibited the largest increase in antiviral activity.

The aim of this work was to evaluate the effect of consumption of extruded maize product added with a low level of the red seaweed Pyropia columbina on colonic and systemic oxidative status using a growing Wistar rat model. Twenty-four (n = 24) male Wistar rats were fed for 60 days with control (C), extruded maize product group (M), or extruded maize product added with red seaweed P. columbina (MP) diets. Rats fed whit MP showed higher catalase (CAT) and glutathione reductase (GR) colon expression than those fed with M or C. Beneficial effects on intestinal mucosal barrier function were observed, which was manifested in decrease of cecal pH (10%) and mucinase activity (67%) and increase of sIgA content (53%). Rats fed with MP diet showed lower cyclooxygenase-2 (COX-2; 43%), inducible nitric oxide synthase (iNOS; 49%), and NF-êâ transcription factor (27%) expression in distal colon than those fed with M or C diets. Also, MP diet exerted a significant antioxidant effect on the serum and liver, increasing hepatic redox index, CAT, and GR activity. Apparent calcium absorption, total skeleton bone mineral content, and bone mineral density of total body were the same among groups. The type of dietary fiber and phenolic compounds from P. columbina could promote antioxidant environment in growing Wistar rats. Fil: Cian, Raúl Esteban. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Llopart, Emilce Elina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Lopez-Oliva Muñoz, María E.. Universidad Complutense de Madrid; España Fil: Weisstaub, Adriana Ruth. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Zuleta, Angela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Drago, Silvina Rosa. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

Fil: Cian, Raul Esteban. Universidad Nacional del Litoral. Facultad de Ingenieria Quimica. Instituto de Tecnologia de los Alimentos; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe; Argentina

Short-term variations of mycosporine-like amino acids (MAAs) in Pyropia columbina (Montage) W.A. Nelson exposed to nitrate (NO3 -) enrichment under different outdoor light treatments during the spring ozone depletion of 2008 in Punta Arenas (Chile) were investigated. Segments of P. columbina thalli were cultivated under three treatments of solar radiation without or with NO3 - supply (0.38 mmol l-1): PAR (P), PAR+UVA (PA), and PAR+UVA+UVB (PAB). Samples were taken at 8:00 h (initial value), 9:30, 12:30, 15:30, and 18:00 h on November 8 and at 9:00 h on November 9 (recovery period). A complex dynamic of MAAs affected by light quality and NO3 - supply was observed. During the light period, the highest content of MAAs was reached under PAB and NO3 - enrichment, whereas MAAs increased during the recovery period in P and PAB with no NO3 - supply. Five MAAs were identified: porphyra-334, shinorine, asterina-330, palythine, and mycosporine-glycine. The hourly accumulation of each MAA varied mainly according to the time of exposure and NO3 - supply. In general, the percentage of porphrya-334 increased, whereas the other MAAs decreased during the exposure period. These results suggest that MAA content in P. columbina varied in the short-term (hours) and the changes were related to the solar irradiance received and NO3 - availability.

In order to promote the use of sub-Antarctic macroalgae as food, four species of marine macroalgae: Macrocystis pyrifera, Durvillaea antarctica, Pyropia columbina, and Callophyllis variegata were studied for their nutritional value. They were collected monthly between October and December 2012 throughout the Strait of Magallanes, sub-Antarctic Chile. The chemical composition, including carbohydrates, proteins, lipids, and vitamins A and C, and the macronutrient, mineral, and fatty acid content were examined. Ash (15.1–34.1 %) and soluble fiber (26.5 to 40.3 %) were the most abundant in these species. Presence of protein was moderate (8.2–25.0 %), with red alga (C. variegata) having the highest value on dry weight (dw). All algal species had lipid contents of less than 5 % dw. Maximum carbohydrate content was observed in P. columbina (9.5 % dw). Potassium was the most abundant essential element found in M. pyrifera (8.51 % dw), while P. columbina was found to be richest in iron (305.5 ± 5.5 μg g−1 dw) and C. variegata showed the highest contents of Cu (17.4 ± 0.7 μg g−1 dw). The most abundant saturated fatty acids were palmitic (C16:0) and myristic acid (C14:0), with values ranging from 4.33 to 9.22 %. The most abundant monounsaturated fatty acid was oleic acid (C18:1ω9). The highest levels of polyunsaturated fatty acid were observed for arachidonic (20:4ω6) and eicosapentaenoic acid (C20:5ω3) or EPA.

A commonly found red alga of the upper intertidal zone of New Zealand rocky coasts is described for the first time as Pyropia plicata sp. nov. This species has been incorrectly known as Porphyra columbina Mont. (now Pyropia columbina (Mont.) W.A.Nelson) for many years. Pyropia plicata is widespread and common, and it is readily distinguished from other species of bladed Bangiales in New Zealand by its distinctive morphology, with pleated blades attached by a central rhizoidal holdfast.

The aim of this work was to evaluate copper-chelating, iron-chelating and anticariogenic activity of peptides obtained by enzymatic hydrolysis of P. columbina protein concentrate and to study the effects of chelating peptides on iron bio-accessibility. Two hydrolyzates were obtained from P. columbina protein concentrate (PC) using two hydrolysis systems: alkaline protease (A) and alkaline protease + Flavourzyme (AF). FPLC gel filtration profile of PC shows a peak having molecular weight (MW) higher than 7000 Da (proteins). A and AF hydrolyzates had peptides with medium and low MW (1013 and 270 Da), respectively. Additionally, AF presented free amino acids with MW around 82 Da and higher content of His and Ser. Peptides from AF showed the highest chelating properties measured as copper-chelating activity (the lowest β-carotene oxidation rate: Ro; 0.7 min−1), iron-chelating activity (33 %), and phosphorous and Ca2+ release inhibition (87 and 81 %, respectively). These properties could indicate antioxidant properties, promotion of iron absorption and anticariogenic activity, respectively. In fact, hydrolyzates promoted iron dialyzability (≈16 %), values being higher than that found for P. columbina seaweed. Chelating peptides from both hydrolyzates can maintain the iron in a soluble and bio-accessible form after gastrointestinal digestion. Fil: Cian, Raúl Esteban. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Garzón, Antonela Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina Fil: Betancur Ancona, David. Universidad Autónoma de Yucatán; México Fil: Chel Guerrero, Luis. Universidad Autónoma de Yucatán; México Fil: Drago, Silvina Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina

Indexación: Web of Science; Scielo. RESUMEN. En Zonas Costeras rocosas, la desecación es gatillada porción Cambios Diarios en los Niveles de marea, y la Evidencia indica experimental de Me Distribución de las algas en la zona intermareal no está Relacionada estafa do palabra capacidad, párr tolerar la desecación. En Este Contexto, la Presencia de Pyropia columbina en la zona alta del intermareal sí Explica Por Su excepcional tolerancia fisiológica a la desecación. Este Estudio explora las Vías Metabólicas involucradas en la tolerancia a la desecación en P. columbina, un Través de la Caracterización de do transcriptoma Bajo Condiciones de hidratación contrastantes. Se obtuvó 1410 TER provenientes de dos Librerías de substracción de ADNc de frondas Naturalmente hidratadas y desecadas. Los transcriptomas de emba Librerías contienen transcritos de Diversas Rutas Metabólicas Relacionadas a la tolerancia. Entre el los transcritos expresados ​​15% estan involucrados en la Síntesis de Proteínas, do Procesamiento y degradacion, 14,4% Asociados un Fotosíntesis y cloroplasto, el 13,1% una mitocondrial Respiración and function, 10,6% al metabolism de la Pared Celular y 7,5% a la Actividad ANTIOXIDANTE, Proteínas chaperonas y factors de Defensa (catalasa, tiorredoxina, Proteínas de choque térmico, P450 citocromo). In Ambás Librerías sí DESTACA La Presencia De genes / Proteínas no descritos en algas. Proporciona Información This El Primer Trabajo molecular Que Estudia la tolerancia a desecación en P. columbina y Sus Resultados Ayudan a explicar los patrones clásicos de Distribución descritos párr algas en la zona intermareal. Palabras clave: Pyropia, desecación porción Estrés, EST, macroalgas, transcriptómica, Proteínas. ABSTRACT. In rocky shores, desiccation is triggered by daily tide changes, and experimental evidence suggests that local distribution of algal species across the intertidal rocky zone is related to their capacity to tolerate desiccation. In this context, the permanence of Pyropia columbina in the high intertidal rocky zone is explained by its exceptional physiological tolerance to desiccation. This study explored the metabolic pathways involved in tolerance to desiccation in the Chilean P. columbina, by characterizing its transcriptome under contrasting conditions of hydration. We obtained 1,410 ESTs from two subtracted cDNA libraries in naturally hydrated and desiccated fronds. Results indicate that transcriptome from both libraries contain transcripts from diverse metabolic pathways related to tolerance. Among the transcripts differentially expressed, 15% appears involved in protein synthesis, processing and degradation, 14.4% are related to photosynthesis and chloroplast, 13.1% to respiration and mitochondrial function (NADH dehydrogenase and cytochrome c oxidase proteins), 10.6% to cell wall metabolism, and 7.5% are involved in antioxidant activity, chaperone and defense factors (catalase, thioredoxin, heat shock proteins, cytochrome P450). Both libraries highlight the presence of genes/proteins never described before in algae. This information provides the first molecular work regarding desiccation tolerance in P. columbina, and helps, to some extent, explaining the classical patterns of ecological distribution described for algae across the intertidal zone. http://ref.scielo.org/jm5rcr

International audience; A new species of bladed Bangiales, Pyropia orbicularis sp. nov., has been described for the first time from the central coast of Chile based on morphology and molecular analyses. The new species was incorrectly known previously as Porphyra columbina (now Pyropia columbina), and it can be distinguished from other species of Pyropia through a range of morphological characteristics, including the shape, texture and colour of the thallus, and the arrangement of the reproductive structures on the foliose thalli. Molecular phylogenies based on both the mitochondrial COI and plastid rbcL gene regions enable this species to be distinguished from other species within Pyropia. P. orbicularis sp. nov. belongs to a well-supported clade of Pyropia from the southern oceans that include specimens from the South Pacific (North, South, Chatham, Stewart, Auckland, and Campbell Island, New Zealand, New South Wales, and Macquarie Island, Australia) including P. columbina and P. plicata. Within this clade, the highest sequence identity was observed between Pyropia orbicularis sp. nov. and Pyropia sp. FIC from the Falkland Islands.