Diatoms with plastids in the plankton of river mouths of the Delta Jacuí, Southern Brazil: a complement to traditional taxonomy

• Autor(a) principal: Laux, Marcele
• Data de Publicação: 2011
• Outros Autores: Torgan, Lezilda Carvalho
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Iheringia. Série Botânica
• Texto Completo: https://isb.emnuvens.com.br/iheringia/article/view/65
• topic: Bacillariophyta; fl oristic composition; subtropical region; Bacillariophyta; composição fl orística; região subtropical

We present the result of the diatoms study at the mouths of the Sinos, Gravataí, Caí and Jacuí rivers, with emphasis on the form of the plastids and their arrangement within the cell from the Jacuí Delta. Although this character has been neglected in recent decades, it is currently recognized by its ecological importance. We analyzed monthly samples, collected at the deep of 20 cm in the pelagic zone from September 2009 to August 2010. 64 taxa, distributed in three classes, 11 orders, 18 families and 23 genera were identifi ed. The most representative familieswere Bacillariaceae (16 taxa), Naviculaceae (8), Aulacoseiraceae (7), Eunotiaceae (5) and Pinnulariaceae (5). The genus Nitzschia was the richest, with 15 species. The highest richness was observed in the Rio dos Sinos (52 taxa) and the lowest in Jacuí River (38 taxa). Only 24 taxa were present in the four rivers and six taxa were exclusive from one river. Considering the previous knowledge of the diatoms occurring in the rivers mouths of the Delta Jacuí, 43 species are mentioned for the fi rst time, which demonstrates the contribution of this study.