ABSTRACT: The Cape Horn Biosphere Reserve (CHBR) is considered as a natural laboratory at the southern end of the sub-Antarctic Magellanic ecoregion. The retreat of glaciers present along the channels and fjords of the CHBR due to global climate change impacts the marine benthic and macroalgae communities hosted in these water bodies. Current knowledge about this subantarctic marine flora is scarce and its first reports date from the 18th and 19th centuries. To solve this knowledge gap, we created the Sub-Antarctic Cryptogamic Herbarium (SCH) thanks to the support of the Cape Horn International Center (CHIC) in the Antarctic and Sub-Antarctic Marine Ecosystems Laboratory (LEMAS), University of Magallanes. As such, the SCH's botanical collection is currently the only gateway to the subantarctic ecosystem's biological legacy. The catalogue below provides information about the ecological and morphological characteristics of macroalgae deposited in the SCH, with the particular focus on those species present in the CHBR. We identified 54 species, most notable of which the Rhodophyta macroalgae accounting for more than 40% of the total composition and a high species richness of algae with filamentous and/or tubular thallus, typical of hyposaline habitats. Additionally, Caleta Olla was significant for its presence of Devaleraeayagan, thereby increasing its distribution known until then, and for being the only site studied to include an exotic invasive species (Polysiphonia morrowii). Despite its geographical proximity with the Diego Ramírez Archipelago, the floristic affinity of macroalgae from the Beagle Channel is greater with that of species from well-protected habitats such as the fjords and channels of the northern part of the CHBR. In the context of the increasing environmental threats, the SCH is essential to evaluate changes in biodiversity and establish conservation measures for these vulnerable sub-Antarctic ecosystems.

RESUMEN: La Reserva de Biosfera de Cabo de Hornos (RBCH) es considerada como un laboratorio natural en el extremo austral de la ecorregión subantártica de Magallanes. Los glaciares presentes a lo largo de sus canales y fiordos están hoy retrocediendo por el cambio climático global, impactando a las comunidades marinas bentónicas, particularmente a las de macroalgas. El conocimiento actual sobre esta flora marina subantártica es aún escaso y sus primeros reportes datan de los siglos XVIII y XIX. Para resolver esta brecha de conocimiento, creamos el Herbario de Criptógamas Subantárticas (HCS) con apoyo del Cape Horn International Center (CHIC) en el Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos (LEMAS), Universidad de Magallanes. El HCS es el repositorio criptogámico más austral del mundo y el único portal actual del patrimonio biológico subantártico. Este catálogo da a conocer las características ecológicas y morfológicas de las macroalgas en ambientes glaciares del Canal Beagle en la RBCH y depositadas en el HCS. Se identificaron 54 especies de macroalgas, destacándose la presencia de algas Rhodophyta que representan más del 40% de la composición total y una alta riqueza de algas con talos filamentosos y/o tubulares, típica de hábitats hiposalinos. Adicionalmente, Caleta Olla se destacó por la presencia de Devaleraea yagan, aumentando su distribución hasta ahora conocida, y por ser el único sitio muestreado en contar una especie exótica invasora (Polysiphonia morrowii). A pesar de su proximidad con el Archipiélago Diego Ramírez la afinidad florística de las macroalgas del Canal Beagle es mayor con especies de hábitats protegidos, como los fiordos y canales que se encuentran al norte de la RBCH. Ante las crecientes amenazas ambientales, el HCS es esencial para evaluar cambios en la biodiversidad subantártica y establecer medidas de conservación para ecosistemas vulnerables.

Abstract Seaweeds have been used by several industrial sectors, such as the food, feed, pharmaceutical and biofuel industries. Thereby, techniques to increase seaweed production are needed due to the rising global demand for biomass. Thus, we investigated the effects of different weekly nutrient pulses [N and P at ratios of 10:1 (T1), 20:2 (T2), and 50:5 (T3)] on the biomass, relative growth rate (RGR) and biochemical composition of Gracilaria domingensis. A control without nutrient pulses was also established. The highest biomass values were recorded in T1. The RGR was more constant in T1 and T2 than in T3 throughout the cultivation. Significant decreases in RGR were observed in the control compared to the other treatments, and null RGR was recorded in T3. Regarding the seaweed biochemical composition, the lowest carbohydrate and lipid content and the highest ash content were recorded in T1. In our study, G. domingensis showed nutritional values similar or even superior to those reported for other seaweeds used as food. We concluded that T1 is the most suitable treatment to increase G. domingensis production. In addition to being the least expensive treatment, in T1, G. domingensis exhibited the highest biomass values, constant RGR, and nutritional composition suitable for human consumption. sectors food feed industries Thereby Thus N 101 10 1 10: T , (T1) 202 20 2 20: T2, (T2) 505 50 5 50: (T3) (RGR established cultivation treatments study G consumption (T1 (T2 (T3 (T

Resumo: Os estudos de algas vermelhas marinhas e estuarinas (Rhodophyta) estão em fase inicial no litoral da Reserva da Biosfera de Sian Ka’na, México. O inventário desses organismos foi feito com base em amostras obtidas em oito amostragens no período do 2009 a 2015 em 22 localidades, sendo oito em ambientes marinhos e quatorze em ambientes estuarinos. Neste levantamento, foram identificadas um total de 182 espécies e táxons subespecíficos de Rhodophyta. A família Rhodomelaceae foi a mais representativa com 65 táxons, seguida por Ceramiaceae com 13 e Delesseriaceae com 12. Dos 182 táxons, 25 são referidos pela primeira vez para a Reserva da Biosfera Sian Ka’an, sendo Harveylithon rupestre, Spongites fruticulosus, Acrochaetium barbadense, Dasya harveyi, Chondria pumila, Spermothamnion repens, Metapeyssonnelia milleporoides e M. tangerina também novos registros para o Caribe mexicano. Das 182 espécies, 119 são epífitas, sendo a maioria, 54, aderidas exclusivamente em outras macroalgas, 29 em raízes de mangue e 8 em folhas de Thalassia. A lista florística apresentada é acompanhada de dados sobre sazonalidade, reprodução, habitat e ambiente. A diversidade de espécies foi comparada entre as temporadas de chuvas de inverno, seca e chuvas de verão durante o período estudado. Rhodophyta da Reserva da Biosfera Sian Ka’an săo tropicais, e a diversidade mais representativa foi encontrada no ambiente marinho com 83 táxons e durante as chuvas de inverno com um total de 132 táxons. Resumo (Rhodophyta Kana, Kana Ka na, na Ka’na México 200 201 2 localidades estuarinos levantamento 18 6 1 12 Kaan, Kaan an, an rupestre fruticulosus barbadense harveyi pumila repens M mexicano 11 epífitas maioria 54 macroalgas Thalassia sazonalidade reprodução estudado tropicais 20 5

Abstract Studies of marine and estuarine red algae (Rhodophyta) are in the early stages in the littoral of the Sian Ka’an Biosphere Reserve, Mexico. The inventory of these organisms was made based on samples obtained from ten sampling during 2009 to 2015 in 22 localities, eight of them in marine and fourteen in estuarine environments. We found 182 species and subspecific taxa of Rhodophyta. The Rhodomelaceae family was the best represented with 65 taxa, followed by Ceramiaceae 13 and Delesseriaceae 12. Of the 182 taxa, 25 are new records Sian Ka’an Biosphere Reserve with Harveylithon rupestre, Spongites fruticulosus, Acrochaetium barbadense, Dasya harveyi, Chondria pumila, Spermothamnion repens, Metapeyssonnelia milleporoides and M. tangerina being new records for the Mexican Caribbean. Of the 182 species, 119 of them are epiphytes, most of them, 54, grew exclusively on other macroalgae, 29 on mangrove roots and 8 on Thalassia leaves. The floristic list is accompanied by data on seasonality, reproduction, habitat, and environment. Species diversity was compared between the winter rains, dry and rainy seasons during the period study. The Rhodophyta of the Sian Ka’an Biosphere Reserve is tropical, and the greatest diversity was found in the marine environment with 83 taxa and during the winter rains with 132. (Rhodophyta Kaan Ka an Mexico 200 201 2 localities environments 18 6 1 12 rupestre fruticulosus barbadense harveyi pumila repens M Caribbean 11 epiphytes 54 macroalgae leaves seasonality reproduction habitat study tropical 132 20 5

Abstract: The coastal waters of Ecuador have emerged as a favorable environment for the growth and development of several species of edible macroalgae or seaweeds. In this study, fatty acid profiles, total soluble polyphenol content, and antioxidant capacity of seven species of macroalgae (four red algae, two brown algae and one green algae) collected from Salinas Bay, Santa Elena Province, Ecuador, were evaluated. Saturated fatty acids C14:0, C15:0, C16:0 and C18:0 were found in almost all organisms, from which palmitic acid showed the highest proportion (10.7-37.1%). Green and brown seaweeds exhibited a major content of unsaturated fatty acids. Monounsaturated fatty acid composition was represented by several isomers of C16:1 and C18:1, mainly palmitoleic (3.0-6.6%) and oleic (0.8-11.1%) acids. Polyunsaturated fatty acid composition ranged from 5.47 to 26.61%, with ratios of total n-6/n-3 acids lower than 3.3. Linoleic (C18:2, n-6, 1.16-7.73%) and eicosapentaenoic (C22:5, EPA, n-3, 1.44-5.92%) acids were found in the majority of the seaweeds. The total polyphenol content of the seaweeds was determined by the Folin-Ciocalteu method (765 nm), and ranged from 147.28 to 1,062.20 mg equivalents of gallic acid (GAE) per 100 g of dry seaweed. The antioxidant capacity was determined by the Trolox equivalent antioxidant capacity (517 nm). Only Acanthophora spicifera, Spatoglossum schroederi, and Ulva lactuca showed good radical-scavenging (14.18-3,379.47 mg Trolox equivalents (TE) per 100 g of dry seaweed). The results confirm the potential use of macroalgae in the study area as an important source of nutritional compounds, especially brown and green algae, which could be a recommended food supplement even in the treatment of some diseases.

ABSTRACT The growth in the number of molecular sequences produced in recent years has provided valuable contributions to the knowledge diversity of red algae (Rhodophyta) in Brazil. However, many works indicate that there is still much to be studied. Here, we highlight the importance of compiling all these data to evidence possible taxonomic and geographic knowledge gaps in red algae through molecular data. So, this study presents a scientometric analysis of the molecular studies carried out on red algae in Brazil, based on the analysis of DNA sequences available in the public database GenBank. Our results demonstrated an increase in published papers from 1994 to 2020, corresponding to 165 studies analyzed. A huge disparity in the production of knowledge was observed, with the southeastern region concentrating the researchers responsible for most of the published studies, with emphasis on those in the University of São Paulo (USP). Bahia and São Paulo states stand out with the highest observed taxonomic richness, respectively. We also could identify the taxonomic groups with more molecular data generated, the sequence number deposited per institution since 1994, the main markers used, the regions that require a greater collection effort, and where the researchers who study red algae in the country are.

Resumen: Antecedentes y Objetivos: Los arrecifes del Parque Nacional Arrecifes de Cozumel constituyen una de las principales formaciones arrecifales de México. Sin embargo, actualmente, son prácticamente inexistentes los estudios ficoflorísticos que permiten detectar cambios en la composición ficoflorística o su afinidad por algún sustrato. Por lo tanto, nuestro objetivo fue determinar la composición taxonómica de macroalgas marinas presentes en el Parque Nacional Arrecifes de Cozumel, así como realizar sus descripciones morfológicas y análisis de afinidad con el sustrato que colonizan. Métodos: Los muestreos se realizaron en octubre y noviembre de 2018 en 14 arrecifes del Parque Nacional Arrecifes de Cozumel, mediante buceo autónomo. Se realizaron observaciones morfo-anatómicas utilizando tanto microscopios ópticos como estereoscópicos. La determinación taxonómica se realizó a partir de literatura especializada. Resultados clave: Se determinaron 42 taxa: cinco Ochrophyta, 12 Rhodophyta y 25 Chlorophyta. La familia mejor representada para Ochrophyta fue Dictyotaceae; para Rhodophyta, Ceramiaceae y Rhodomelaceae; y para Chlorophyta, Halimedaceae. Se describen nuevos registros para el Parque Nacional Arrecifes de Cozumel incluyendo a Lobophora guadeloupensis como nuevo registro para México. Adicionalmente, se identificaron cuatro diferentes sustratos para las algas: psamofítico (33%), epilítico (32%), epizoico (19%) y epífito (16%). Los arrecifes más diversos fueron La Francesa (LF) y Santa Rosa (SR), y los menos diversos fueron Chankanaab (CK) y Tormentos (TM). Conclusiones: Aunque muchos de los registros previos en el área fueron confirmados en el presente estudio, la presencia de 18 nuevos registros reveló, por un lado, la falta de monitoreos constantes de la riqueza algal de la región, y, por otro lado, la necesidad de contar con descripciones morfológicas o referencias fotográficas que permitan contrastar los registros previos con los actuales. Dada la importancia del Parque Nacional Arrecifes de Cozumel, nuestros resultados, además de ofrecer información actualizada, representan un punto de partida para estudios en biología de la conservación.

Abstract: Background and Aims: The reefs of the Parque Nacional Arrecifes de Cozumel constitute one of the main reef formations in Mexico. However, up to date phycofloristic studies that allow detecting changes in the phycofloristic composition or its affinity for some substrates are practically non-existent. Our aim was to determine the taxonomic composition of marine macroalgae present in the Parque Nacional Arrecifes de Cozumel, as well as realize their morphological descriptions and an analysis of their affinity with the substrate they colonize. Methods: The sampling was carried out in October and November 2018 by autonomous diving in 14 reefs of the Parque Nacional Arrecifes de Cozumel. Morphological observations were made using optical and stereoscopic microscopes. The taxonomic determination was made using specialized literature. Key results: Fourty-two taxa were determined: five Ochrophyta, 12 Rhodophyta and 25 Chlorophyta. The best-represented family for Ochrophyta was Dictyotaceae; for Rhodophyta, Ceramiaceae and Rhodomelaceae; and for Chlorophyta, Halimedaceae. New records for the Parque Nacional Arrecifes de Cozumel are described, including Lobophora guadeloupensis as a new record for Mexico. Additionally, four different substrates for the algae were identified: psammophytic (33%), epilithic (32%), epizoic (19%) and epiphytic (16%). The most diverse reefs were La Francesa (LF) and Santa Rosa (SR), whereas the least diverse were Chankanaab (CK) and Tormentos (TM). Conclusions: Although many of the previous records in the area were confirmed in the present study, the presence of 18 new records revealed, on the one hand, the lack of constant monitoring of the algal richness of the region, and on the other hand, the need for morphological descriptions or photographic references that allow contrasting the previous records with the current ones. Given the importance of the Parque Nacional Arrecifes de Cozumel, our results, in addition to offering updated information, represent a starting point for studies in conservation biology.

Resumen: Antecedentes y Objetivos: Desde la publicación del libro sobre las macroalgas marinas de Cuba en 2015 se han publicado nuevos registros y cambios taxonómicos. Por lo anterior, el objetivo del presente trabajo fue presentar una quinta revisión sistemática actualizada, que incluye Ochrophyta (Clase Phaeophyceae), Rhodophyta y Chlorophyta. Métodos: Se recopiló la información disponible en publicaciones científicas, tesis de licenciatura, maestría y doctorado, e informes científico-técnicos de especialistas reconocidos, considerando aquellas que no fueron comprendidas en la revisión anterior o que fueron publicadas después de 2015. Los taxones encontrados fueron ordenados sistemáticamente, los nombres actualizados y la sinonimia revisada según AlgaeBase y la literatura más reciente. Las especies se ordenaron alfabéticamente dentro de cada familia. La distribución de cada taxón se resumió para nueve zonas consideradas como Distritos Ecológicos (zonas) de la plataforma cubana. Resultados claves: Se presenta un listado florístico actualizado con 569 especies, una subespecie, 25 variedades y 21 formas. Se añaden a la anterior revisión 38 especies, de las cuales siete son nuevos registros para Cuba: Hydrolithon boergesenii, Neogoniolithon mamillare, N. propinquum, N. rhizophorae, Lithothamnion crispatum, Liagoropsis schrammii y Peyssonnelia rubra. Se da la distribución de cada uno de estos taxones en las nueve zonas de la plataforma cubana. Conclusiones: Las zonas que presentaron más especies son aquellas que han tenido un mayor esfuerzo de muestreo o donde predominan los fondos rocosos arrecifales, aunque no se han inventariado detalladamente las macroalgas en la zona mesolitoral, bahías y lagunas costeras.

Abstract: Background and Aims: Since the publication of the book on Cuban marine macroalgae in 2015, new records have been found and taxonomic changes have been published. Therefore, the objective of this publication is to present a fifth updated systematic review, that includes Ochrophyta (Class Phaeophyceae), Rhodophyta and Chlorophyta. Methods: These results were recorded from information available in scientific papers, bachelor, master and doctoral theses, as well as scientific-technical reports from recognized specialists, considering those not included in the last review or that were published after 2015. The taxa were systematically ordered, the names and synonymy were reviewed according to Algaebase and the most recent scientific literature. Species were arranged alphabetically within each family. The distribution of each taxon was resumed for nine Ecological Districts (zones) of the Cuban shelf. Key results: An updated floristic list with 569 species, one subspecies, 25 varieties, and 21 forms is presented. Thirty-seven species are added to the previous review of which seven are new records for Cuba: Hydrolithon boergesenii, Neogoniolithon mamillare, N. propinquum, N. rhizophorae, Lithothamnion crispatum, Liagoropsis schrammii, and Peyssonnelia rubra. The distribution of these taxa in the nine zones of the Cuban shelf is provided. Conclusions: The zones showing more species have had a greater sampling effort or were predominantly rocky reef bottoms. However, macroalgae have not been inventoried in detail in the intertidal zone, bays, and coastal lagoons. Zones with fewer species coincide in having a narrower shelf where rocky substrates dominate, although macroalgae have not been inventoried in the intertidal zone, bays, and coastal lagoons.

Resumen Antecedentes. El conocimiento de la riqueza de especies de algas en el estado de Yucatán ha variado considerablemente en el tiempo; desde los trabajos en 1935 de Taylor que registra 27 especies, hasta trabajos en el 2010 que incluyen 285 spp. Objetivos. Actualizar la diversidad de macroalgas y cianoprocariontes, para integrar la Flora Ficológica de Yucatán, en términos de riqueza de especies y distribución por ambientes generales para detectar los hábitats que han sido estudiados con distinta intensidad. Métodos. Se seleccionaron registros de las especies de macroalgas y cianoprocariontes de tres fuentes: publicaciones, colecciones de herbario y proyectos, para generar la base de datos con registros a nivel de especie o infraespecífico; y datos sobre cuáles y cuantos ambientes han sido encontrados. Resultados. Se registraron 462 especies: 194 Rhodophyta, 138 Chlorophyta, 54 Phaeopyceae y 76 Cyanoprokaryota, donde 35 son registros nuevos, no incluidos en integraciones previas. Los registros se consideraron de acuerdo con su distribución en los siguientes ambientes generales: arrecife, costero o laguna. El ambiente que registró mayor riqueza de especies fue el arrecife con 310 taxones infragenéricos, aunque provienen principalmente de arrecife Alacranes. Conclusiones. Hay una gran diferencia en el número de especies mencionadas en distintos estudios, resultado de diferentes métodos, intensidad, época de muestreo, sitios, o hábitats estudiados. La costa norte de Yucatán es muy extensa y consideramos que, si bien existen muchos trabajos sobre macroalgas bentónicas, algunos taxones y ambientes han sido poco estudiados. Tal es el caso de Cyanoprokaryota y Phaeophyceae y las comunidades algales de ambientes arrecifales.

Abstract Background. Knowledge on the algal species richness in the state of Yucatán has varied considerably over time; from the works in 1935 by Taylor that recorded 27 species, to works in 2010 that included 285 spp. Goals. Update the diversity of macroalgae and cyanoprokaryotes, to integrate the Yucatan Phycological Flora in terms of species richness and distribution by general environments to detect the habitats that have been studied with different intensity. Methods. Macroalgae and Cianoprocariontes species records were selected from three sources: publications, herbarium collections, and projects, to generate the database with records at the species or infraspecific level, and data from which and how many habitats they have been found. Results. 462 species were registered: 194 Rhodophyta, 138 Chlorophyta, 54 Phaeopyceae and 76 Cyanoprokaryota, where 35 are new records not included in previous integrations. Records were considered according to their distribution in the following general environments: reef, coastal, or lagoon. The environment that recorded the highest species richness was the reef with 310 infrageneric taxa; although they mainly come from the Alacranes reef. Conclusions. There is a great difference in the number of species mentioned in different studies, this is the result of different methods, intensity, sampling time, sites, or habitats studied. The northern coast of Yucatan is very extensive, and we consider that, although there are many works on benthic macroalgae, some taxa and habitats have been little studied. Such is the case of Cyanoprokaryota and Phaeophyceae, and reef environments.

Resumen Antecedentes. Gracilariaceae es una de las familias más diversas y abundantes de algas rojas marinas, la mayoría de sus especies exhiben una alta variabilidad morfológica y superposición de caracteres. En la Península de Yucatán se han registrado 30 especies, pero aún se desconoce la identidad filogenética de muchas de ellas. Preguntas: ¿Se sobreestima la diversidad actual de la familia en el área? Especies de estudio: Crassiphycus caudatus, C. corneus, C. usneoides, Gracilaria flabelliformis, G. hayi, G. cf isabellana, G. microcarpa, G. occidentalis, G. suzanneae, Gracilariopsis tenuifrons. Sitios y años de estudio: Campeche: km 33 carretera Champotón, Bahía Tortuga, Puente Xen Kan III, Punta Xen, Sabancuy, 2017, 2018; Yucatan: Puerto Sisal, Puerto Progreso, Puerto Chicxulub, Puerto Telchac, 2018; Quintana Roo: Playa 88, Xcalacoco, Punta Esmeralda, 2019. Métodos. Análisis filogenéticos (con secuencias COI-5P y rbcL), apoyados por métodos de delimitación de especies de ADN, distancias genéticas y comparaciones morfológicas, permitió identificar molecularmente cada especie recolectada. Resultados. Se confirmó la identidad filogenética de 10 especies de Gracilariaceae, dos de las cuales fueron nuevos registros para el Atlántico mexicano: G. hayi y G. suzanneae. Conclusión: El presente estudio demostró que la evaluación molecular resultó ser muy útil para la estimación de la diversidad, por lo que futuras identificaciones filogenéticas para el resto de las morfoespecies registradas en el área, permitirán una mejor aproximación de la diversidad de las especies de Gracilariaceae.

Abstract Background. The Gracilariaceae is one of the most diverse and abundant families of marine red algae. Most species in this family exhibit high morphological variability and overlapping of characters. In the Yucatan Peninsula 30 species have been historically recorded, but the phylogenetic identity for many of them is still unknown. Questions: Is the current diversity of the family in the area overestimated? Studied species: Crassiphycus caudatus, C. corneus, C. usneoides, Gracilaria flabelliformis, G. hayi, G. cf isabellana, G. microcarpa, G. occidentalis, G. suzanneae, Gracilariopsis tenuifrons. Study site and dates: Campeche: km 33 carretera Champotón, Bahía Tortuga, Puente Xen Kan III, Punta Xen, Sabancuy, 2017, 2018; Yucatan: Puerto Sisal, Puerto Progreso, Puerto Chicxulub, Puerto Telchac, 2018; Quintana Roo: Playa 88, Xcalacoco, Punta Esmeralda, 2019. Methods. Phylogenetic analysis (with COI-5P and rbcL sequences), supported by DNA species delimitation methods, genetic distances and morphological comparisons, allowed us to molecularly identify the specimens collected. Results. The phylogenetic identity of 10 species of Gracilariaceae was confirmed, two of which are new records for the Mexican Atlantic: G. hayi and G. suzanneae. Conclusion. The study demonstrated that the molecular assessment has proved to be very useful for the diversity evaluation, thus, the future phylogenetic identifies for the rest of morphospecies recorded in the area will allow a better approximation of Gracilariaceae diversity species.

RESUMEN En este estudio paleoecológico se enfocó en las facies grainstone rica en algas rojas coralinas en los carbonatos del Mioceno Inferior (Aquitaniano) de la Formación Qom en la sección Vartun del centro de Irán. Las algas rojas coralinas identificadas en las facies son principalmente no geniculadas, aunque también se caracterizaron formas geniculadas mediante análisis de láminas delgadas. Las algas identificadas están representadas por Melobesioidea (Lithothamnioncf.valens,Lithothamnioncf.rovereoti,Lithothamnioncf.peleense, yLithothamnionspp.), Mastophoroidea (Neogoniolithonsp.,Spongitesspp., ySpongitescf.fruticulosus),Sporolithonspp (Sporolithonspp. ySporolithoncf.airoldii), y por coralinas geniculadas (Corallina). Los taxones de algas muestran principalmente formas grandes y grumosas de fructicoso. Donde predomina consistentemente con alta energía del agua en el ambiente arrecifal identificado. La presencia de algas del Mioceno Inferior indica que la exposición de carbonatos tuvo lugar en aguas cálidas tropicales a subtropicales en la zona eufótica marina durante el Aquitaniano. Asimismo, tanto la alta energía del agua como la agitación de los sedimentos, dieron lugar a características tafonómicas tales como fragmentación, abrasión, y desarticulación.

ABSTRACT In this paleoecological study we focused on coralline red algae-rich shoal grainstone facies in the Lower Miocene (Aquitanian) carbonates of the Qom Formation in the Vartun section in central Iran. The identified coralline red algae are mainly non-geniculate, although very rare geniculate forms of corallines were also recognized in thin section analysis. The identified algae are represented by Melobesioideae (Lithothamnioncf.valens,Lithothamnioncf.rovereoti,Lithothamnioncf.peleense, andLithothamnionspp.), Mastophoroideae (Neogoniolithonsp.,Spongitesspp., andSpongitescf.fruticulosus),Sporolithonspp. (Sporolithonspp. andSporolithoncf.airoldii), and geniculate coralline (Corallina). The algal taxa mainly display fruticose and lumpy growth forms. The dominance of the former is consistent with high water energy in the identified shoal environment. The presence of Lower Miocene algae indicates that deposition of carbonates took place in warm tropical to subtropical waters in a euphotic marine environment during the Aquitanian. Likewise, high water energy and sediment agitation resulted in taphonomic features such as fragmentation, abrasion, and disarticulation.

Resumen: Antecedentes y Objetivos: Los sistemas estuarinos veracruzanos cubren 1166 km2 correspondientes a 14 lagunas costeras que constituyen uno de los ambientes acuáticos con mayor diversidad y productividad. Estos son ambientes críticos para especies económicamente importantes, como las macroalgas, que dependen de ellos para su reproducción, alimentación, establecimiento y refugio. Aunque lo anterior los hace candidatos ideales para estudios de biología de la conservación, solo hay dos contribuciones previas a 1995 sobre ficología estuarina. Por tanto, el objetivo de este trabajo fue elaborar un listado sistemático actualizado de las macroalgas estuarinas de Veracruz, junto con un análisis gráfico, que contribuya al conocimiento del grupo y sirva como referencia para posteriores investigaciones biogeográficas, ecológicas o de conservación. Métodos: Se revisó la literatura ficológica publicada de 1963 a septiembre de 2022, así como la base de datos del herbario UAMIZ, para complementar y actualizar los registros. Para la determinación taxonómica de los ejemplares se hizo un estudio de morfología externa. La sinonimia y estatus nomenclatural fueron revisados en AlgaeBase. A partir de los registros obtenidos se realizó un análisis gráfico. Resultados clave: Se presenta una lista actualizada con 113 especies de macroalgas estuarinas: 62 Rhodophyta, 26 Phaeophyceae, Ochrophyta y 25 Chlorophyta, distribuidas en 24 órdenes, 38 familias y 68 géneros. Conclusiones: De acuerdo con lo observado, son evidentes los escasos o nulos estudios ficológicos en ambientes estuarinos veracruzanos, lo que origina un vacío en el contexto de la diversidad de macroalgas estuarinas. Este listado, además de ser una contribución actualizada para Veracruz, es un punto de partida para emprender futuros análisis que ayuden a establecer áreas de importancia biológica en estos ambientes, con el fin de maximizar la diversidad. Además, es evidente la necesidad de un monitoreo ficofloristico constante en los estuarios.

Abstract: Background and Aims: The Veracruz estuarine systems cover 1166 km2, corresponding to 14 coastal lagoons, that constitute one of the aquatic environments with the greatest diversity and productivity. They are critical environments for economically important species, such as macroalgae, which depend on them for their reproduction, feeding, establishment and refuge. Although the above makes them ideal candidates for conservation biology studies, there are only two contributions prior to 1995 on estuarine phycology. Therefore, the objective of this work was to elaborate an updated systematic list of the estuarine macroalgae of Veracruz, together with a graphical analysis, which contributes to the knowledge of the group and serves as a reference for subsequent biogeographical, ecological or conservation research. Methods: Phycological literature published from 1963 to September 2022, as well as the UAMIZ herbarium database, were reviewed to complement and update the records. For the taxonomic determination of the specimens, an external morphological study was carried out. The synonymy and nomenclatural status were reviewed in AlgaeBase. From the records obtained, a graphic analysis was performed . Key results: An updated list with 113 species of estuarine macroalgae is presented: 62 Rhodophyta, 26 Phaeophyceae, Ochrophyta and 25 Chlorophyta, distributed in 24 orders, 38 families and 68 genera. Conclusions: According to what was observed, there are few or no phycological studies in Veracruz estuarine environments, which causes a gap in the context of the diverse estuarine macroalgae. This list, in addition to being an updated contribution for Veracruz, is a starting point to undertake future analyses that help establish areas of biological importance in these environments, in order to maximize diversity. In addition, the need for constant phycofloristic monitoring in estuaries is evident.

Resumen: Antecedentes y Objetivos: El complejo Gracilaria mammillaris es un conjunto de especies de algas rojas cuya identificación resulta complicada debido al reducido número de caracteres morfológicos que las delimitan. Esta problemática se acentúa cuando se encuentran distribuidas en una misma región. El objetivo del presente estudio fue determinar, mediante análisis morfométricos, la existencia de caracteres que permitan la delimitación de cinco especies del complejo Gracilaria mammillaris en el Atlántico mexicano. Métodos: Veinticuatro caracteres morfométricos de cinco especies del complejo Gracilaria mammillaris fueron sometidos a un análisis de componentes principales para evaluar la existencia de un patrón de variación morfológica. Los componentes resultantes fueron analizados mediante un NP-MANOVA. Se calculó y graficó la media aritmética y los intervalos de confianza para los caracteres con un mayor peso en la discriminación. Se realizó un análisis de agrupamiento UPGMA para sustentar los resultados anteriores. Resultados clave: Los análisis mostraron que la única especie del complejo que se segregó fue Gracilaria curtissiae, el resto no mostraron diferencias significativas entre ellas. En promedio, el largo y ancho de las células corticales de la porción media del talo fueron más grandes en G. curtissiae que en las otras; y el largo y ancho de las células medulares en la porción media del talo resultaron ser en promedio más pequeñas en G. curtissiae que en los demás miembros del complejo. El análisis de agrupamiento sustentó los resultados anteriores. Conclusión: Un proceso de especiación en curso podría ser la respuesta a que las propiedades morfológicas de cuatro de las cinco especies estudiadas aún no sean distinguibles, pero sí las filogenéticas. Análisis futuros de reloj molecular y filogeográficos permitirán entender mejor el estado de divergencia en el que se encuentran estos taxones.

Abstract: Background and Aims: The Gracilaria mammillaris complex is a group of red algae, whose identification is complicated due to the small number of morphological characters that delimit them. This problem is accentuated when they are distributed in the same area. The aim of this work was to determine, through morphometric analysis, the existence of characters that allow and facilitate the delimitation of five species of the Gracilaria mammillaris complex in the Mexican Atlantic. Methods: Twenty-four morphometric characters of five species of the Gracilaria mammillaris complex were subjected to a principal component analysis, to evaluate the existence of a pattern of morphological variation between species. The resulting components were analyzed by means of a NP-MANOVA. The arithmetic means and confidence intervals for the characters with a greater weight in discrimination were calculated and plotted. A UPGMA clustering analysis was performed to support these results. Results: The analyses showed that the only species in the complex that differs was Gracilaria curtissiae, the rest did not show significant differences between them. On average, the length and width of the cortical cells of the medium portion of the thallus were larger in G. curtissiae than in the other species; and the length and width of the medullary cells in the medium portion of the thallus proved to be on average smaller in G. curtissiae than in the other species of the complex. Clustering analysis supports the previous results. Conclusions: An ongoing speciation process could be the answer to the fact that the morphological proprieties of most of the studied species are not yet distinguishable, but the phylogenetic ones are. Future molecular clock and phylogeographic analyses will allow a better understanding of the state of divergence in which these taxa are found.

Resumen Las macroalgas dependen de sustratos específicos para su crecimiento y propagación. Esta relación es importante para comprender el funcionamiento de los arrecifes de coral. En México, sin embargo, los estudios sobre este tema son escasos. Así, en el presente estudio se determinó la diversidad de especies de macroalgas en el Parque Nacional Arrecifes de Xcalak (PNAX), en relación con el sustrato que colonizan. En julio del 2012, se seleccionaron 10 sitios de muestreo en 4 zonas del PNAX: canal de Zaragoza (C), laguna arrecifal 1 (LA1), laguna arrecifal 2 (LA2), y arrecife frontal (AF). Con ayuda de transectos y cuadrantes se recolectaron manualmente especímenes de 61 taxones de macroalgas (entre ellos un morfotipo), principalmente rodofitas, sobre 3 sustratos abióticos y 18 bióticos. De estos taxones, 17 especies constituyeron nuevos registros para el PNAX y 1 para la costa de Quintana Roo. La diversidad fue mayor en LA (3.89), seguido de AF (3.71), observando especies comunes entre ambas zonas. Las familias Halimedaceae, Udoteaceae y Anadyomenaceae se observaron creciendo sobre sustrato abiótico, mientras que las familias Halimedaceae y Dictyotaceae constituyeron sustrato para otras rodofitas. El número de macroalgas registrado en el PNAX representa 10.4% del total registrado para la costa de Quintana Roo.

Abstract Macroalgae depend on specific substrata for their growth and propagation. This relationship is essential to understand the functioning of coral reefs. In Mexico, however, studies on this subject are scarce. Therefore, in the present study, the diversity of macroalgae species in the Xcalak Reefs National Park (PNAX) was determined in relation to the substrata they colonize. In July 2012, 10 sampling sites were selected in 4 zones of the PNAX: Zaragoza Canal (C), Lagoon Reef 1 (LA1), Lagoon Reef 2 (LA2), and Fore Reef (AF). With the help of transects and quadrants, specimens of 61 taxa of macroalgae (among them a morphotype) were collected manually, mainly Rhodophyta, on 3 abiotic and 18 biotic substrata. Of these taxa, 17 species were new records for the PNAX and 1 for the Quintana Roo’s coast. The diversity was higher in LA (3.89), followed by AF (3.71), observing common species between both zones. The families Halimedaceae, Udoteaceae, and Anadyomenaceae were observed growing on abiotic substrata, while the families Halimedaceae and Dictyotaceae constituted substrata for other Rhodophyta. The number of macroalgae registered in the PNAX represents 10.4% of the total registered for Quintana Roo’s coast.

RESUMEN Esta investigación es un aporte al conocimiento de algunas especies de macroalgas marinas que fueron recolectadas durante las expediciones científicas “Almirante Padilla” (2016-2017) y “Almirante Campos” (2018-2019), en las que participó el Instituto de Investigaciones Marinas y Costeras-Invemar con el proyecto: Biodiversidad y Condiciones Oceanográficas del Estrecho de Gerlache “Biogerlache-Antártica”. Se realizaron recolectas usando draga tipo Shipek y videos subacuáticos con un ROV (Remote Operated Vehicle). Se identificaron seis especies, cuatro Rhodophyta y dos Ochrophyta-Phaeophyceae. Se incluye información sobre la profundidad y zonación donde las macroalgas fueron halladas, y su relación con registros previos para el área de estudio.

ABSTRACT This research is a contribution to the knowledge of some marine macroalgae species collected during the “Admiral Padilla” (2016-2017) and “Admiral Campos” (2018-2019) scientific expeditions, in which the Marine and Coastal Research Institute-Invemar participated with the project “Biodiversity and Oceanographic Conditions of the Gerlache Strait-Biogerlache-Antartica”. Samples were taken using a Shipek dredge; and underwater video recordings were made with a ROV (Remote Operated Vehicle). Six (6) species were identified: four (4) Rhodophyta and two (2) Ochrophyta-Phaeophyceae. Depth and zonation information where the macroalgae were found is included, and their relationship with previous records for the study area.

Abstract. Gracilaria chilensis is distributed in New Zealand (including Chatham Island) and South America. This species has a three-stage sexual life cycle, as well as asexual and vegetative reproduction, and is commercially important as it is a valuable source for producing agar. However, basing the crops exclusively on clonal reproduction and vegetative propagation has led to a reduction in their genotypic diversity, an increase in their susceptibility to infection by epiphytes, and a decrease in their quality. Thus, it is important to establish indoor cultures of G. chilensis from thalli with a mixed reproductive regime (sexual and asexual) that maintains the genetic variability of the cultivars. In this study, the biomass, growth rate, and productivity of indoor cultures of G. chilensis were evaluated (as a first approach) using various culture media [i.e., von Stosch medium (VS), Basfoliar® Aktiv (BF), and mixtures of VS and BF, namely, VS/BF-A and VS/BF-B]. The VS/BF-A medium showed the best results in terms of biomass (51.8 ± 3.7 g m-2), growth rate (4.55 ± 0.43 %d-1), and productivity (14 g m-2 d-1), including the occurrence of thalli with cystocarps. The positive results using the VS/BF-A medium could be attributed to the fact that BF provides different elements (K, Cu, Mo, and Zn) that are crucial, since they are involved in numerous physiological functions in the algae, and also to the N:P ratio utilized (1:1), which positively affects growth and productivity. This information provides pivotal updated knowledge regarding cultures of G. chilensis under controlled conditions, promoting its successful cultivation for productive purposes.

Resumen: Gracilaria chilensis se distribuye en Nueva Zelanda (incluida la Isla Chatham) y Sudamérica. Esta especie tiene un ciclo de vida sexual de tres fases, así como una reproducción asexual y vegetativa, y es comercialmente importante, ya que es una valiosa fuente para producir agar. Sin embargo, los cultivos basados exclusivamente en la reproducción clonal y la propagación vegetativa han provocado una reducción de la diversidad genotípica, incrementando la susceptibilidad a la infección por epifitos y una disminución de la calidad. Por ello, es importante establecer cultivos de interior de G. chilensis a partir de talos, con un régimen reproductivo mixto (sexual y asexual), que mantenga la variabilidad genética de los cultivares. En este estudio, fue evaluada (como primera aproximación) la biomasa, la tasa de crecimiento y la productividad de los cultivos de interior de G. chilensis utilizando varios medios de cultivo [i.e., medio von Stosch (VS), Basfoliar® Aktiv (BF), y mezclas de VS y BF, es decir, VS/BF-A y VS/BF-B]. El medio VS/BF-A mostró los mejores resultados en términos de biomasa (51,8 ± 3,7 g m-2), tasa de crecimiento (4,55 ± 0,43 %d-1) y productividad (14 g m-2 d-1), incluyendo la ocurrencia de talos con cistocarpos. Los resultados positivos utilizando el medio VS/BF-A podrían atribuirse al hecho de que el BF proporciona diferentes elementos (K, Cu, Mo y Zn) que son cruciales, ya que están involucrados en numerosas funciones fisiológicas en las algas, y la razón N:P utilizada (1:1) ya que afecta positivamente al crecimiento y la productividad. Esta información proporciona un conocimiento actualizado fundamental sobre los cultivos de G. chilensis en condiciones controladas, promoviendo su cultivo exitoso con fines productivos.