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.

ABSTRACT Hypnea pseudomusciformis was recently described from South America, and has three morphological variants: “musciformis”, “nigrescens”, and “valentiae”. Information on the biology of these variants may help to explain this species’ wide morphological variation despite the absence of genetic divergence among variants. More morphological and ecological data has accumulated on the “musciformis” variant occurring on the Brazilian coast than for the others. In this study, we described the reproductive morphology of a tropical “nigrescens” population and investigated its phenology to provide crucial biological information about this taxon, and perhaps also assist in answering questions about the systematics of H. pseudomusciformis variants. The population analyzed showed no significant fluctuations in its total biomass throughout the year. All reproductive stages were frequently recorded during this study, which contributes greatly to our knowledge of the reproductive morphology of the “nigrescens” variant. Phenological variations were correlated with environment variables, such as air and sea-surface temperatures, insolation, precipitation, and humidity. Male gametophytes were frequently present, which has never been reported for the “musciformis” variant. We showed that, despite being members of the same genetic species, the “nigrescens” and “musciformis” morphological variants exhibit remarkable differences in their ecology and biology.

Hypnea musciformis ocorre amplamente na costa nordeste do Brasil, sendo uma das mais importantes fontes naturais de k-carrageenana que é utilizado nas indústrias alimentícia e cosmética. Apesar do potencial de explotação, pouco se sabe sobre sua ecologia. O objetivo deste estudo foi conhecer a biologia e ecologia de H. musciformis no Brasil através da análise do estoque de biomassa e da flora acompanhante. Duas populações de H. musciformis foram analisadas nas praias de Stella Maris e Itacimirim (Bahia, Brasil). Oito amostragens foram realizadas entre 2007 e 2009, durante as estações seca e chuvosa. As algas foram coletadas ao longo de transectos (20 m) utilizando quadrados (0,04 m²) em três diferentes regiões hidrodinâmicas dos recifes (TP, PRR e FRR). t-Test, Teste de Dunn e ANOVA paramétrica e não-paramétrica foram utilizados para a análise estatística. Foram identificadas 17 espécies hospedeiras e 41 espécies associadas. O maior estoque de biomassa foi observado durante a estação seca. Em Stella Maris, a região com maior estoque de biomassa foi FRR, e em Itacimirim, TP apresentou biomassa maior. Este estudo permite supor que sazonalidade, microhabitats, hidrodinamismo e fatores em microescala contribuem para a variação no estoque de biomassa em populações de H. musciformis.

Hypnea musciformis occurs widely in the northeast coast of Brazil, and it is one of the most important natural sources of k-carrageenan, which is used in food and cosmetic industries. Despite its potential for exploitation little is known about its ecology. The aim of this study was to investigate the biology and ecology of H. musciformis in Brazil through analyses of biomass stock and accompanying flora. Two populations of H. musciformis were analyzed: those on the beaches of Stella Maris and Itacimirim (Bahia, Brazil). Eight samplings were conducted between 2007 and 2009 during the dry and rainy seasons. The algae were sampled along transects (20 m) using quadrats (0.04 m²) in three different hydrodynamic regions of the reefs (TP, PRR and FRR). The t-Test, Dunn's Test and parametric and nonparametric ANOVA were used for statistical analyses. 17 host species and 41 associated species were identified. The highest biomass stock was observed during the dry season. On Stella Maris, the region with the highest biomass stock was FRR; on Itacimirim, TP had the highest biomass value. This study permits the assumption that seasonality, microhabitat, hydrodynamic and micro scale factors contribute to variation in biomass stock in H. musciformis populations.

Durante estudo sobre as espécies de Hypnea do litoral do estado da Bahia foram encontrados exemplares de Hypnea cornuta (Kützing) J. Agardh em coletas realizadas no extremo sul do estado. Este é o primeiro relato de H. cornuta para o estado da Bahia, Brasil. É fornecida uma caracterização detalhada dos aspectos morfológicos, anatômicos e reprodutivos desta espécie.

During study of the species of Hypnea of the coast of Bahia specimens of Hypnea cornuta (Kützing) J. Agardh were found in the southern state. This is the first report of H. cornuta for the state of Bahia, Brazil. It is provided a detailed characterization of morphological, anatomical and reproductive aspects of this species.