A comunidade microfitoplanctônica do Arquipélago de São Pedro e São Paulo (Atlântico Norte-Equatorial): variação diurna e espacial

Abstract

The present study was developed in the São Pedro and São Paulo Archipelago, with the objective to describe the structure of the microphytoplankton community, and establish its diurnal and spatial variation. The samplings were carried out in two stations (Enseada and Cabeço da Tartaruga) during five consecutive days (May 12 to 16, 2008) of the rainy season, during early morning and late afternoon, by subsurface horizontal hauls of 10 minutes duration with plankton net of 45 mm of mesh size. A total of 131 taxa were recorded, out of which 117 in Cabeço station and 89 in Enseada. The group of dinoflagellates was the most diverse, represented by 90 taxa belonging to 17 genera, highlighting the Ceratium genus with 33 species. The cyanophyceae Trichodesmium thiebautti Gomon ex Gomont was the only dominant species in the area, influencing the community structure, and serving as indicator species for the area. There was a greater number of species at the Cabeço than in Enseada. The marine planktonic oceanic species predominated, with 61.26% of the overall species richness. The diversity and evenness were in general higher in both sampling stations. At Cabeço station, the values of species diversity were between a minimum of 0.76 bits.cell -1 and a maximum of 4.27 bits.cell -1 and evenness varied between 0.16 and 0.84. At the Enseada station, it was registered a minimum of 2.91 bits.cell -1 and a maximum of 3.87 bits.cell -1 , and evenness with minimum and maximum values of 0.64 and 0.84, respectively. The cluster analysis showed the formation of three distinct associations of species, with Cabeço and Enseada species in separate groups, highlighting the differences between the communities of the two studied sites. In each station, there was no significant difference between samples of different hours. The study area is characterized by a floristic composition typical of stable, transparent and oligotrophic waters. Resumo: O presente trabalho foi desenvolvido no Arquipélago de São Pedro e São Paulo, com o objetivo de descrever a estrutura da comunidade microfitoplanctônica, assim como estabelecer sua variação diurna e espacial. As amostras foram coletadas em duas estações (Cabeço da Tartaruga e Enseada) durante cinco dias consecutivos (12 a 16/05/08) do período chuvoso, nos horários da manhã e da tarde, por meio de arrastos horizontais subsuperficiais de 10 minutos de duração, com uma rede de plâncton com abertura de malha de 45 µm. Um total de 131 táxons foram registrados, dos quais 117 foram na estação Cabeço da Tartaruga e 89 na Enseada. O grupo dos dinoflagelados foi o mais diverso, representado por 90 táxons pertencentes a 17 gêneros, destacando-se o gênero Ceratium com 33 espécies. A cianofícea Trichodesmium thiebautti Gomont ex Gomon foi a única espécie dominante na área, influenciando a estrutura da comunidade, servindo como a espécie indicadora da área. Houve um número maior de espécies na estação Cabeço do que na Enseada. As espécies marinhas planctônicas oceânicas predominaram, com 61,26% da riqueza ...

When Bergmann's rule fails: evidences of environmental selection pressures shaping phenotypic diversification in a widespread seabird

“…FN (Souza et al 2013) and Rocas (Jales et al 2015). In addition, ichthyoplankton are more abundant around the SPSP than tropical waters (Tiburcio et al 2011), the interaction of the Equatorial Undercurrent with the archipelago topography slows the movement of the current at a local level and generates vortices, which increase the mixing of the water column (i.e. disrupting the surface thermocline) and the residence time of waters around the SPSP (Araujo and Cintra 2009).…”

Dinoflagellates in tropical estuarine waters from the Maraú River, Camamu Bay, northeastern Brazil

“…They are assigned to the protist lineage Alveolata due to the presence of flattened vesicles under the plasma membrane, which can be empty or contain cellulose plates (Elbrächter and Hoppenrath 2009). Most species are characterized by the presence of two distinct flagella (transverse and longitudinal), which enable the typical whirling swimming of dinoflagellates (Taylor 1987). Dinoflagellates display high diversity in morphology, nutrition, and habitat.…”

“…There are c. 2500 extant species of dinoflagellates known so far (Elbrächter and Hoppenrath 2009). The great diversity of dinoflagellates occurs in marine and brackish environments in which dinoflagellates constitutes one of the most important planktonic groups (Taylor 1987;Elbrächter and Hoppenrath 2009).…”

“…On the northeast Brazilian coast, most of the studies were made in the state of Pernambuco and focused on the ecology of the phytoplankton community (e.g. Rosevel-da-Silva et al 2005;Leão et al 2008;Tiburcio et al 2011. Despite the importance of dinoflagellates, knowledge about their occurrence and distribution in northeastern Brazil remains scarce.…”

The composition and new records of micro- and mesophytoplankton near the Vitória-Trindade Seamount Chain

“…Subsequently, the search focused on phytoplankton species already reported in marine waters of Brazil, with the aim of finding new records (Koening & Lira 2005, Procopiak et al 2006, Tenenbaum et al 2006, Haraguchi & Odebrecht, 2007, Sousa et al 2008, Villac et al 2008, Villac & Tenenbaum 2010, Islabão & Odebrecht 2011, Proença et al 2011, Tiburcio et al 2011, Garcia & Odebrecht 2012, Jardim & Cardoso 2013, Menezes et al 2015. All species synonyms were checked through AlgaeBase, in order to confirm the records in the publications consulted.…”