Cryptophyceae population dynamics in an oligo-mesotrophic reservoir (Ninféias pond) in São Paulo, southeast Brazil

Abstract

Cryptophyceae population dynamics in an oligo-mesotrophic reservoir (Ninféias Pond) in São Paulo, southeast Brazil). Vertical and temporal dynamics of Cryptophyceae population was studied in an oligo-mesotrophic reservoir, the Ninféias Pond, located in the Parque Estadual das Fontes do Ipiranga, south of the Municipality of São Paulo, state of São Paulo, southeast Brazil. Material studied was collected from January to December 2000. Individual specimens of Cryptophyceae were present in all samples. Thermal stratifi cation and mixing processes do not seem to directly infl uence temporal distribution of Cryptophyceae, but may interfere in their vertical distribution. Four out of the 10 species presently identifi ed (C. brasiliensis, C. curvata, C. erosa and C. marssonii) presented greatest population densities and highest frequency of occurrence. PCA showed that the species' vertical distribution scale was more important towards ordination of samples. Greatest growth of C. erosa was noticed below 1 m depth in all months sampled. Cryptomonas brasiliensis was highly representative at the surface of reservoir, mainly during the warmer months (January-February, October and November). Considering the temporal scale, results did not demonstrate seasonal distribution of Cryptophyceae, but in the vertical scale, results evidenced a heterogeneous distribution of the group.RESUMO -(Dinâmica da população de Cryptophyceae em um reservatório oligo-mesotrófi co (Lago das Ninféias) em São Paulo, Brasil sudeste). A dinâmica vertical e temporal das populações de Cryptophyceae foi estudada em um ambiente oligo-mesotrófi co -Lago das Ninféias -situado no Parque Estadual das Fontes do Ipiranga, sul do Município de São Paulo, estado de São Paulo, região sudeste do Brasil. O material estudado foi coletado de janeiro a dezembro de 2000. A presença de representantes da classe Cryptophyceae foi detectada em todas as amostras coletadas. Estratifi cação térmica e mistura parecem não ter infl uência direta sobre a distribuição temporal das Cryptophyceae, mas podem atuar sobre a repartição vertical de suas espécies. Das 10 espécies identifi cadas, quatro (C. brasiliensis, C. curvata, C. erosa and C. marssonii) apresentaram as maiores densidades populacionais e as mais altas freqüências de ocorrência. A ACP mostrou que a escala vertical de distribuição das espécies pesou mais na ordenação das unidades amostrais. A maior densidade de C. erosa foi detectada abaixo de 1 m de profundidade em todos os meses amostrados. Cryptomonas brasiliensis foi altamente representativa na superfície do reservatório, principalmente, durante os meses mais quentes do ano (janeiro, fevereiro, outubro e novembro). Na escala temporal, os resultados não demonstraram distribuição sazonal das Cryptophyceae, porém, na escala vertical, tais resultados mostraram uma distribuição heterogênea das espécies. Palavras-chave: Brasil, Cryptophyceae, dinâmica de populações, reservatório urbano oligo-mesotrófi co

Changes in phytoplankton spatial and temporal dynamics in a Brazilian tropical oligotrophic reservoir after net cage installation

“…The contribution of the Cryptophyceae to biovolume alternated with Chlorophyceae and Cyanobacteria along the studied period also corroborate Klaveness (1988Klaveness ( , 1989 and Bicudo et al (2005Bicudo et al ( , 2009, who stated that the increase Table 1 Physical and chemical variables related to the water in the Ponte Pensa River in Ilha Solteira reservoir and sampling stations (S1 = 1, S2 = 2, and S3 = 3), between August 2011 and July 2013 of Cryptophyceae occurs when other algae groups decrease, characterizing them as ''opportunistic,'' and Borges et al (2010), who recorded increased Cryptophyceae density when Cyanobacteria density decreased.…”

“…According to Bicudo et al (2009), one particularity of Cryptophyceae is their continuous presence in aquatic ecosystems, i.e., they occur along the entire year, but hardly present as the dominant species. Differently from what was discussed by Bicudo et al (2009), our results confirm the dominance of Cryptophyceae. Rhodomonas lacustris was dominant in over 59 % of the analyzed samples.…”

Identification of species and genotypic compositions of Cryptomonas (Cryptophyceae) populations in the eutrophic Lake Hira, Japan, using single-cell PCR

“…This species has been reported worldwide (e.g., Menezes and Novarino 2003;Melo et al 2004;Xia et al 2013). Seasonal changes of the Cryptomonas species composition in a Brazilian reservoir indicated that C. curvata tended to dominate during low temperature periods (15-20°C, between March and September), and then decreased during the summer (Bicudo et al 2009). The relative abundance of C. curvata in L. Hira also remained low during the high water temperature period (> 30°C), and our results were consistent with previous reports (Fig.…”

“…Cryptomonas marssonii is ubiquitously distributed under various environmental conditions (Smolander and Arvola 1988;Kim et al 2007). In Brazil, C. marssonii is one of the most common Cryptomonas species (Menezes and Novarino 2003), and its density increases during high temperature periods (Bicudo et al 2009). Rott (1988) examined flagellate assemblages in four mid-altitude lakes (average surface water temperature of 24.3˚C) and four high-mountain lakes (average surface water temperature of 10.8˚C) in Austria, and reported that C.…”

Temperature × light interaction and tolerance of high water temperature in the planktonic freshwater flagellates Cryptomonas (Cryptophyceae) and Dinobryon (Chrysophyceae)

“…With this restriction in mind, the experimentally determined T opt (15°C-19°C; Ojala 1993b, this study) and T max of~23°C are consistent with field observations (reviewed by Reynolds 2006). For instance, in a Brazilian reservoir C. curvata was a dominant species during the austral winter when temperature ranged from 13°C to 18°C and declined during summer (Bicudo et al 2009). Similarly, in many temperate lakes cryptophytes including C. curvata dominate in spring and early summer (reviewed by Reynolds 1984, Sommer 1986.…”