Placoneis itamoemae Straube, Tremarin & Ludwig

Straube, Arielli, Tremarin, Priscila Izabel, Castro-Pires, Emanuela Cristina De, Marquardt, Gisele Carolina & Ludwig, Thelma Alvim Veiga, 2013, Morphology, ultrastructure and distribution of Placoneis itamoemae sp. nov. (Cymbellaceae) from Brazil, Phytotaxa 76 (3), pp. 55-62: 56-57

publication ID 10.11646/phytotaxa.76.3.13


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Placoneis itamoemae Straube, Tremarin & Ludwig

sp. nov.

Placoneis itamoemae Straube, Tremarin & Ludwig   sp. nov. ( Figs 1–24 View FIGURE 1–14 View FIGURES 15–19 View FIGURES 20–24 )

Type:— BRAZIL. Paraná: Balsa Nova County, Papagaios river , 25°27'55"S, 49°45'58"W, January/2001, UPCB 44567 View Materials - diatom collection of the Botany Department, Universidade Federal do GoogleMaps   Parana; holotype slide UPCB 44567 View Materials , designated here in Fig. 3 View FIGURE 1–14 ; isotype slide ANSP GC 26818 ( Academy of Natural Sciences , Philadelphia)   .

Valves elliptic-lanceolate, length 26.0– 37.9 µm and breadth 10.0– 13.4 µm (n=47), with rostrate ends. Raphe sternum straight and narrow, central area slightly expanded, formed by 5–6 irregularly shortened median striae on either side of the raphe, 1–3 (usually 2) rounded isolated pores on one side of the central area. Central pores more expanded internally, located on the prominent central nodule. Raphe straight with proximal ends externally slightly expanded, rounded and internally deflected to the side of central pores; distal ends turned into opposite directions and each one with distinct morphology, hooked-like at one end of the valve and gradually curved at the other. Internally, the distal raphe ends terminate in small helictoglossae. Striae radiate, arched in the middle portion of valve, becoming parallel to convergent at the apices, 17–21 in 10 µm, extending onto the valve mantle, formed by one row of rounded to elliptical areolae, 36–39 in 10 µm. Etymology: —This species is named in honor of Dr. Ita Moema Valente-Moreira, a retired diatom researcher from Universidade Federal do Paraná.

Ecological data:— The collected sample from Papagaios river showed high temperature (22.5ºC), slightly acid conditions (pH 6.7), 102.8 µ -1 of conductivity and 1.52 mg /L of dissolved oxygen ( Visinoni 2002).


Academy of Natural Sciences of Philadelphia