Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Background. Dinoflagellates (Dinoflagellata) are recognized by the morphological characteristics of their specific cell cover called amphiesma. This complex has presented advantages for the description of many species, however, there are many others whose basic morphological information is scarce, or for which no consensus has been reached regarding nomenclatural issues. An example of this problem is the case of Durinskia baltica Carty & Cox 1986, a name associated with a dinoflagellate that has had circumscription and systematic position problems because it has undergone multiple name changes associated with its morphology, passing through four different genera (Glenodinium, Peridinium, Peridiniopsis and Durinskia) since its first description. Objectives. The objective of this work was to make a historical review of the characters that have been used in the description of species of Durinskia to identify the taxonomic discrepancies that the genus has experienced. Methods. Bibliographical information on Durinskia and its records worldwide were compiled. The criteria used to separate the species were compared. Results. In two comparative tables on the taxonomic history of D. baltica and related species, the morphological and environmental characters used, and the key points in the criteria to circumscribe this species are presented and critically reviewed. Conclusions. With the current state of knowledge, it is not possible to resolve whether D. baltica is an exclusively freshwater species or if it also inhabit marine environments.

Background. Frederick Michael Liebmann explored Mexico for two years visiting Veracruz, Oaxaca, and Puebla collecting plants, seaweeds, and freshwater algae. These samples were entrusted to J. Agardh in Lund for determination and published in 1847. Goals. Recognize Liebmann and J. Agardh for being the pioneers in the study of Mexican algae and update the taxonomic and nomenclatural status of these names, the first ones in the phyco-inventory of Mexico. Methods. We consulted the integrating works worldwide such as the Index Nominum Algarum (INA) and AlgaeBase whose main task has been to collect scattered and unclear information on the algal names published to date. The original publications and criteria of the International Code of Algae, Fungi and Plants were used, citing the articles or recommendations offered to clarify, resolve, or endorse any taxonomic opinion. Results. Twenty-one species listed by Agardh, for the entire itinerary of Liebmann's expedition, consisting of 196 names, were considered new. Eight additional new species from other collections were described by him. Only twelve of them are names in current use (accepted taxonomically). There are included 27 non-Mexican taxonomic or nomenclatural proposals. Liebman's contributions represent 12% of the total taxa (1698) registered for Mexico. The new species described by J. Agardh are 1% of this total, and eight are part of 23% of the endemisms for the Pacific of Mexico. Conclusions. The origin and taxonomic significance of some of J. Agardh's proposals have remained uncertain after 175 years, so it is necessary to carry out studies that delve into these taxa to arrive at an accurate and updated inventory.

Background. Illustrated records of the Podolampadaceae from Mexican waters are scarce. Goals. To study the thecal morphology of the genera Blepharocysta and Podolampas and to document the occurrence of planktonic species in both Atlantic and Pacific waters around Mexico were the main objectives of the present study. Methods. Bottle and net samples were taken from the water column in the southern Gulf of California (Baja California Sur state) and the southern Gulf of Mexico (Veracruz and Yucatan states) from 2008 to 2019. Light and scanning electron microscope (SEM) photos were taken, and observations on thecal morphology of the podolampadaceans were made. Results. Thecal morphology of Blepharocysta denticulata, B. okamurae, B. paulsenii, B. splendor-maris, Podolampas bipes, P. elegans, P. palmipes, P. reticulata and P. spinifera was examined; SEM micrographs of seven species are shown. Blepharocysta cells exhibited a wide variation of thecal features. Short descriptions are accompanied by references to publications that contain illustrations. The history of the study of the podolampadaceans is presented. Conclusions. Morphological data are not sufficient to confirm the status of some doubtful podolampadaceans or to clarify infraspecific, species and generic relationships within the family; therefore, molecular data are necessary.

Background. In 2011, we published an overview of Mexican freshwater algae. Objectives. Eleven years later, we make an evaluation of the advances in each one of the subjects related to the knowledge of the continental algal groups: number of species registered in the country and in each state of the republic, types of publications with floristic information, distribution of the taxa in the states and a list of the new species described in the period. Methods. The bibliographic and floristic information databases available online (bdLACET, AlgaeBase) were analyzed. Results. The most reliable number of records of valid taxa, no synonims, in Mexico is 4,268. Several states increased their floristic list by more than 50%. Conclusions. We discuss the importance of continuing with floristic work and the elements that comprise it, the role played by the current policies of scientific journals regarding inventory work, and the importance of having reliable regional databases.

Background. The macroalgae of the tropical Mexican Pacific have been studied and results published in numerous texts since the 1940s. Nevertheless, there is no compilation of records of macroalgae from reef communities, nor have specific inventories of reef macroalgae been prepared. Objective. To integrate the knowledge generated on the tropical Mexican Pacific coral reef macroalgae. Carry out an integration of the knowledge generated on reef macroalgae and make inventories of these macroalgae in the reefs of Guerrero and Oaxaca in the Mexican tropical Pacific.  Methods. Sørensen's similarity analysis and Non-Metric Multidimensional Scaling (NDMS) analysis were applied to data of algal composition from different coral reefs to determine their distribution patterns. The ANOSIM analysis method was applied to demonstrate the significant differences between groups. Results. The total number of macroalgal species was 144, 100 Rhodophyta, 32 Chlorophyta and 12 Ochrophyta-Phaeopyceae; 75 were exclusive to Guerrero, 24 to Oaxaca, and the number of shared species was 45. El Zacatoso, Guerrero, had 92 species and was the locality with the greatest specific richness. The Sørensen Index indicated a similarity of more than 50% among most localities, but with a clear separation between the communities of Guerrero and Oaxaca. Four groups were formed by localities' species with the NMDS analysis without seasonal effect (rainy and dry), ANOSIM shows significant differences among the localities of each group. Conclusion. This work represents the first inventory of the reef-inhabiting macroalgae of Guerrero and Oaxaca, the only states in the Mexican tropical Pacific with specific systematic reports on this type of coral reef algae. This study provides baseline information to develop a regional monitoring program, a diagnosis of the degree of disturbance of coral reefs and generate conservation strategies and plans for these ecosystems.

Antecedentes. El conocimiento de la riqueza de especies de algas en el estado de Yucatán han variado considerablemente en el tiempo; desde los trabajos en 1935 de Taylor que registran 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.

Background. Studies on marine benthic dinoflagellates (MBD) began in 1942 from the offshore region of Oaxaca, based on water column samples. Subsequently, in ten Mexican maritime states, both epibenthos and plankton samples have been collected, species have been cultured, and field and laboratory studies have been carried out. Many of these species are related to ciguatera fish poisoning and diarrhetic shellfish poisoning. Goals. The objective of this contribution was to review the studies on MBD in Mexican waters. Methods. Available literature on MBD published from 1942 to 2022 was analyzed. Results. A review of the studies on MBD is presented, subdivided into two sections: (1) taxonomic diversity (morphological and molecular) and (2) toxigenicity and species interactions. A map of the studies on MBD, a list of taxonomic and ecological studies on MBD in Mexico and a list of ca. 60 species (mainly Prorocentrum, followed by Amphidinium, Gambierdiscus, Ostreopsis and Sinophysis) is presented, accompanied by scanning electron microscopic images of 15 species. Knowledge of the toxigenicity of MBD is still scarce. Experimental studies on MBD begun in this century have shown great potential; Prorocentrum lima has been the main object of these studies. Conclusions. Studies on MBD have slowly increased, probably due to the availability of a greater number of strains, as well as to international collaboration. Confirmed links between particular benthic harmful algal blooming species and events associated with the etiology of toxic syndromes are rare. However, the lack of reports does not indicate an absence of intoxications. Studies on toxicity, allelopathy, ecology, impact on cultivated organisms, biosynthesis of metabolites and biotechnological potential still need to be undertaken in Mexico.

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.

Background: Texture and organic matter content of the surface sediments of aquatic ecosystems provide important information about the nature of the sedimentary processes that occur there also to exerting a notable influence on the supply of nutrients in the water column and on the composition and distribution of benthic biota. Goals: Due to the lack of antecedents, in this study an evaluation of the textural characteristics and organic matter content of the surface sediments of Lake Metztitlán was carried out. Methods: Sediment samples (n= 35) were collected in the dry and rainy season for 2 years. The granulometric analysis was carried out using sieving and pipetting techniques. The content of organic matter (OM) was determined by the ignition technique at 550 °C. Results: The textural analysis of sediments allowed to recognize a wide predominance of silty clay in the most of the lake bottom, in addition to two smaller groups: clayey silt, along the front of the mouth of the lake’s main tributary, and clays, in the areas of lower hydrodynamic. Furthermore, the proportion of organic matter in the sedimenst ranged between 7 and 12%. The data obtained did not show significant differences between the seasons of the year analyzed. Conclusions: The predominance of fine sediments with content of organic matter, probably have a major role in the trophic structure of the lake being the detritus an important path to the energy flow in the ecosystem.