Staurosira sp. 1

Ruwer, Daiane Trevisan & Rodrigues, Liliana, 2021, Sediment diatoms from Upper Paraná River floodplAiN lAKeS: New recordS, Iheringia, Série Botânica (e 2021012) 76, pp. 1-16 : 5

Staurosira sp. 1

( Figs. 28-31)

Valves lanceolate dilated in the middle. Cuneate, subrostrate ends. Axial area narrow and lanceolate. The central area is lanceolate. Striae alternate and short, slightly radiated to the central area. Length: 11-21 μm; width: 3.9- 5.0 μm; striae 15-17 in 10 μm. The specimens observed are similar to Pseudostaurosira decipiens Morales, Chávez & Ector. Nevertheless , the P. decipiens are different from the studied population, due the lower striae density, ends rostrate in smaller individuals, and presence of a slight swelling in the region between the ends and the central area ( Morales et al. 2012). The studied population is consistent with the type of material described by Metzeltin et al. (2005), except for valve length values.

Material examined: BRAZIL, MATO GROSSO DO SUL: Batayporã, Garças Lake , 21.IX.2017, sediment, D. T. Ruwer (Nupélia UEM - 18085 - 95, 18097) .

Occurrence: first citation for Upper Paraná River floodplain.