In recent years, the use of molecular data in algal systematics has increased as high-throughput sequencing (HTS) has become more accessible, generating very large data sets at a reasonable cost. In this perspectives paper, our goal is to describe how HTS technologies can advance algal systematics. Following an introduction to some common HTS technologies, we discuss how metabarcoding can accelerate algal species discovery. We show how various HTS methods can be applied to generate datasets for accurate species delimitation, and how HTS can be applied to historical type specimens to assist the nomenclature process. Finally, we discuss how HTS data such as organellar genomes and transcriptomes can be used to construct well resolved phylogenies, leading to a stable and natural classification of algal groups. We include examples of bioinformatic workflows that may be applied to process data for each purpose, along with common programs used to achieve each step. We also discuss possible strategies and the new skill set that will be required to fully embrace HTS as a part of algal systematics, along with considerations of cost and experimental design. HTS technology has revolutionized many fields in biology, and will certainly do the same in algal systematics.

In spite of the length of the Brazilian coastline, studies of marine phytoplankton species in offshore areas have been largely neglected. Regarding phytoplankton species composition, the aim was to assess biodiversity status, species frequency, and the similarities at different sites along the Vitoria-Trindade Seamount Chain. Phytoplankton net samples were analyzed. One hundred and seventy five infrageneric taxa were identified. They represented four phyla, viz., Cyanobacteria, Bacillariophyta, Dinophyta, and Ochrophyta. Dinophyta was the most diverse, and its genus Tripos the largest contributor. This genus also represented more than half of the most common taxa in the sampled area. Thirty-five new infrageneric taxa were recorded, 12 of which are new reports for Brazil. Neritic stations assemblages were markedly different from those of seamounts and deep offshore. The high species diversity, especially among dinoflagellates can be considered typical of tropical oligotrophic waters. The new records demonstrate the gap in knowledge of phytoplankton biodiversity in Brazil.

Nephroselmis is composed by unicellular nanoplanktonic organisms, occurring predominantly in marine environments. Currently, 14 species are taxonomically accepted. Nephroselmis viridis was described in 2011 and strains were isolated from Indic and Pacific Oceans. Since then, it was not recorded in other places. A strain was isolated from coastal waters of Brazil by micropipetting and washing, and cultivated in f/2 medium for morphological observations (light, confocal, SEM and TEM) and molecular phylogeny inferences (maximum likelihood and Bayesian). The cells are asymmetrical, have two unequal flagella, one cup-shaped chloroplast with an eyespot, and a large starch covered pyrenoid. Chloroplast thylakoids intrude into the pyrenoid and organic scales cover all cell body and flagella. Molecular phylogeny (18S rRNA) clustered the isolated strain with other Nephroselmis viridis sequences, and the species is the sister of the N. olivacea, the type species of the genus. Morphology and molecular phylogeny corroborate the strain identification, and it is the first time this species is recorded in Brazil and in the Atlantic Ocean.

Confesso que esta de longe foi a parte que me deu mais prazer em escrever, pois me fez relembrar de vários momentos compartilhados com pessoas que ajudaram, direta ou indiretamente, para a conclusão deste trabalho.Em primeiro lugar quero agradecer à minha amada família, que me deu todo suporte, que aceitou minhas ausências prolongadas, e acreditou no meu sonho. Amo muito vocês por tudo que fizeram e ainda fazem por mim.Agradeço imensamente à professora Dra Sônia Maria Flores Gianesella, minha orientadora, por ter aberto as portas de seu laboratório e por todos os ensinamentos ao longo deste tempo que compartilhamos juntas. À Dra Flávia Marisa Prado Saldanha-Corrêa, por todo suporte técnico e intelectual. Pelas conversas nos lanches da tarde, pela grande paciência em me ensinar e aturar os meus defeitos, pela grande amizade adquirida neste tempo de convivência. É muito bom encontrar pessoas tão queridas ao longo da nossa jornada pela vida. Ao professor Dr. Frederico Pereira Brandini, pela amizade e confiança, por todos os momentos de boas discussões científicas e pela imensa ajuda na revisão deste documento. Sou muitíssimo grata pela força! Ao meu amado, meu anjo da guarda, Fernando Takashi Kanemoto, por todos os bons momentos vividos juntos, pela imensa calma e paciência, pelas boas conversas de trabalho, pela ajuda com este documento... Agradeço por ter você na minha vida! Aos técnicos do DOB, Tomás, Dona Cida, Ruthe, Cidinha, Davi e André, por todas as ajudas ao longo desse tempo e também pela amizade.