Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil)

Abstract

Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). This study evaluated the heterogeneity in periphytic algal community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, as artificial. This experiment was carried out in a lateral arm from Rosana Reservoir, formed by Corvo Stream (Paranapanema river basin), in the period from November 21 st to December 12 nd , 2003, characterized as a warm and rainy period. Changes in species composition were assessed using the similarity indices. 495 taxa were registered in the phycoperiphytic community, distributed in 133 genera and 11 classes. Zygnemaphyceae, Bacillariophyceae, Chlorophyceae and Cyanophyceae presented higher species number, in both substrata. Staurodesmus, Closterium, Staurastrum and Cosmarium (Desmidiales); Gomphonema and Eunotia (Pennales); Characium, Scenedesmus and Desmodesmus (Chlorococcales); Anabaena and Aphanocapsa (Nostocales and Chroococcales, respectively) were the most species-rich genera. The epiphytic community reached the highest species richness in the 15 th successional day. Regardless the substratum type, the number of species was probably related to the high concentrations of nutrients (phosphorus and nitrogen).

Desmídias perifíticas de cinco lagoas do Distrito Federal, Brasil: I - Gênero Cosmarium Corda ex Ralfs

“…Brasil: Paraná (Felisberto & Rodrigues 2010a). C. phaseolus apresenta grande variação intraespecífica, especialmente em relação ao formato da célula.…”

“…C. pseudoconnatum Nordstedt var. pseudoconnatum tem sido registrada com frequência em ambientes brasileiros (Lopes & Bicudo 2003, Silva & Cecy 2004, Felisberto & Rodrigues 2004, 2010a, b, Araújo & Bicudo 2006. Para a variedade pluriradians, entretanto, não foram encontrados registros.…”

“…Brasil: Paraná (Felisberto & Rodrigues 2008, 2010a, b, Bortolini et al 2010). Segundo Prescott et al (1981), esse táxon apresenta grande variação morfológica intraespecífica, podendo ser confundido com outros táxons como C. sphagnicolum West et West.…”

“…Brasil: Paraná (Felisberto & Rodrigues 2008, 2010a, Mato Grosso (Camargo et al 2009). Um táxon próximo seria C. portianum Archer, o qual, porém, apresenta seno bem mais aberto do que C. reniforme.…”

“…Brasil: Paraná , Felisberto & Rodrigues 2010a Células médias, ligeiramente mais largas que longas; constrição mediana profunda, seno reto e fechado; semicélulas trapeziformes, ápice truncado, ângulos basais arredondados; células granuladas com verrugas bi ou tri-denticuladas distribuídas nas margens das semicélulas, formando um arranjo circular na sua face ventral; ápice achatado; em vista lateral, cloroplasto axial, com dois pirenóides por semicélula. Compr.…”