Andréa Tucci

Chlorophyceae das represas Billings (Braço Taquacetuba) e Guarapiranga, SP, Brasil

Biodiversity of Chlorophyceae in two of the greatest reservoirs from the metropolitan region of Sao Paulo municipality, Billings and Guarapiranga, which supply water for millions of people, was studied. The samples were collected every two months, in specific sites in both reservoirs, from January to December 2004. The samples were filtered using a plankton net (20 µm) and preserved with formaldehyde. Thirty six taxa belonging to two orders, ten families and 24 genera, were identified, described and illustrated. The genus Desmodesmus presented the highest species richness (four), followed by Ankistrodesmus e Scenedesmus (three species each). Ten taxa are firstly reported to the studied reservoirs. Eight taxa were found exclusively in Guarapiranga reservoir and three only in Billings reservoir, whereas 70% of the identified taxa were common to both reservoirs. The high species richness of Chlorophyceae confirms the floristic dominance of this class in tropical and commonly eutrophyzed water bodies.

Chlorococcales (exceto Scenedesmaceae) de pesqueiros da Região Metropolitana de São Paulo, SP, Brasil: levantamento florístico

Studies in fishing ponds have mainly focused on economic issues and environmental impacts, while studies on the flora of micro algae are rarely performed. Therefore, the objective of this study was to perform a survey of the Chlorococcales from ten fishing ponds located in the Metropolitan Region of Sao Paulo. We identified 38 taxa, distributed in eight families, 19 genera and four varieties that are not typical of the species. With the exception of Scenedesmaceae, Chlorellaceae and Coelastraceae had the greatest number of taxa, 10 and eight species respectively, while Micractiniaceae, Radiococcaceae and Treubariaceae had the lowest numbers of taxa and frequencies of occurrence. Dictyosphaerium pulchellum was the only species with 90% frequency of occurrence. Out of the 38 taxa identified, 19 had a frequency of occurrence between 30-55%, indicating a greater distribution of these species among the studied fishing ponds, corroborating the information in the literature, which argue that the Chlorococcales, Chlorophyceae species are well distributed in different Brazilians aquatic systems. The Scenedesmaceae family will be addressed separately due to its high wealth of taxa.

Cyanobacteria de pesqueiros da região metropolitana de São Paulo, Brasil

As cianobacterias estao amplamente distribuidas em ambientes eutrofizados, onde comumente podem formar floracoes toxicas, como em pesqueiros. O objetivo desse estudo foi avaliar a biodiversidade de cianobacterias em dez pesqueiros da Regiao Metropolitana de Sao Paulo (RMSP). As amostras foram coletadas na subsuperficie, atraves de arrasto horizontal com rede de plâncton, em dois periodos: setembro/outubro de 2001 e fevereiro/marco de 2002, totalizando 20 amostras. As amostras foram preservadas em formol a 4-5% e estudadas ao microscopio fotonico. Foram identificadas 23 especies de cianobacterias pertencentes a cinco ordens, sete familias e 15 generos. Synechococcales foi a ordem com maior riqueza de especies (8), seguida por Chroococcales (6), Pseudanabaenales (5), Oscillatoriales (2) e Nostocales (2). Aphanocapsa Nageli e Microcystis Kutzing ex Lemmermann foram os generos mais representativos, com cinco e quatro taxons respectivamente. Dos 23 taxons identificados, 22% foram considerados frequentes, 35% pouco frequentes e 43% raros. Aphanocapsa annulata G.B. McGregor, Aphanocapsa delicatissima W. West & G.S. West, Aphanocapsa incerta (Lemmermann) Cronberg & Komarek, Aphanocapsa holsatica (Lemmermann) Cronberg & Komarek e Microcystis aeruginosa (Kutzing) Kutzing estiveram presentes em sete pesqueiros Esta e a primeira citacao de Aphanocapsa annulata para o estado de Sao Paulo.

Scenedesmaceae (Chlorococcales, Chlorophyceae) de pesqueiros da Região Metropolitana de São Paulo, SP, Brasil: levantamento florístico

A survey on the Scenedesmaceae from 10 fishing ponds in Sao Paulo Metropolitan Region (RMSP) was performed. The samples were collected from the sub-surface, horizontally towed with a plankton net (20 µm mesh), in two periods: September-October 2001 (dry season) and February-March 2002 (rainy season), with a total of 20 samples. The samples were preserved in 4-5% formaldehyde solution, and studied under a photonic microscope. Twenty-six taxa of Scenedesmaceae were identified, distributed in 10 genera, 23 species, two varieties and one taxonomic form. Desmodesmus lefevrei (Deflandre) An, Friedl & Hegewald, Dicloster acuatus Jao, Wei & Hu and Scenedesmus baculiformis Chodat are cited for the first time for the State of Sao Paulo. Scenedesmus and Desmodesmus are the best represented genera, with nine and eight species, respectively.

New planktic species of Kirchneriella Schmidle (Chlorophyceae, Selenastraceae) from Brazilian freshwaters

New planktic species of Kirchneriella Schmidle (Chlorophyceae, Selenastraceae) from Brazilian freshwaters. In the samples collected from an artificial lake, located in the metropolitan region of São Paulo, an interesting algal population morphologically similar to Kirchneriella Schmidle was found. The crescent-shaped cells were oriented, inside the colony, with their convex faces toward the periphery of the colony resembling those of K. roselata Hindák. However, the remaining portions of the mother cell wall with more or less radial arrangement similar to the connective mucilaginous threads of the genus Selenodictyon Uherkovich & Schmidt ex Comas & Komárek were also observed. After further studies based on light microscope, the studied material proves to be morphologically distinguishable from K. roselata, although it never forms rosette-like groups, which are typical in K. roselata. The remaining parts of the mother cell wall more or less radially disposed near the cells (autospores just released from the mother cell wall) are not connective threads. Thus, a new species, K. brasiliana, is described in this paper. According to literature, the main diagnostic feature of Selenodictyon is the crescent-shaped cells attached by their concave faces to mucilaginous stalks like in Dictyosphaerium; however, remaining portions of the mother cell wall more or less radially oriented were also formed in some Kirchneriella populations. Therefore, the authors consider that such feature could be misinterpreted as connective mucilaginous threads, which raises doubts regarding the validity of Selenodictyon.

First record and ecologic aspects of Isthmochloron neustonica Zalocar & Pizzarro (Tribophyceae) in São Paulo State, Brazil

ABSTRACT - (First record and ecologic aspects of Isthmochloron neustonica Zalocar & Pizzarro (Tribophyceae) in Sao Paulo State, Brazil). We present the morphometric characteristics of Isthmochloron neustonica populations as well as their abundance and the relationship with some environmental characteristics in a fishpond. This is the first record of the species in Sao Paulo State and second citation to Brazil. Isthmochloron neustonica was described in neustonic habit; in this study, with sampling for phytoplankton analysis, it was found in high density and short duration blooming (time interval up to 15 days). It represented 59% of total phytoplankton density on May 26, 2010, forming a delicate and bright film on the water surface, in an environment with high concentration of nutrients and associated with drought and low temperature. The species has a restricted range in South America, probably due to their biological characteristics, such as small cell size and neustonic habit. Few records in literature can also be one of the reasons that hampers the identification of the species in subtropical environments.Keywords: Ecology, freshwater, taxonomyRESUMO - (Primeiro registro e aspectos ecologicos de