Cymbella tumidula var. salinarum Grunow

Silva, Weliton Jose da, Jahn, Regine, Ludwig, Thelma Alvim Veiga, Hinz, Friedel & Menezes, Mariangela, 2015, Typification and taxonomic status re-evaluation of 15 taxon names within the species complex Cymbella affinis / tumidula / turgidula (Cymbellaceae, Bacillariophyta), PhytoKeys 53, pp. 1-25 : 8

Cymbella tumidula var. salinarum Grunow

Cymbella tumidula var. salinarum (Grunow) Cleve, Kongl. Svenska Vetensk.-Akad. Handl., ser. 4, 26(2): 171, 1894.

Basionym.

Cymbella salinarum Grunow in Schmidt, A. Schmidt’s Atlas Diatom.-Kunde, Pl. 9, fig. 28, 1875.

Holotype.

Preparation 1603 in the Grunow Collection in the Naturhistorisches Museum Wien (W).

Lectotype

(designated here). An individual on preparation 1603, in the Grunow Collection in the Naturhistorisches Museum Wien (W), represented by the illustration in Krammer (2002, Fig. 25: 13).

Type locality.

Salinen von Zaule (Trieste, Italy).

Valves lanceolate, dorsiventral, dorsal and ventral margins convex; ends subcapitate; length 34.0 µm, breadth 10.7 µm, L/B ratio 3.2; axial area linear-lanceolate, slightly arched, central area rounded; striae 14 in 10 µm, becoming 15 toward ends, 1 isolated pore.

Remarks.

This taxon presents morphometric characteristics similar to Cymbella tumidula var. tumidula , except it has wider valves. Cleve (1894) recorded specimens of Cymbella tumidula var. salinarum with 27-40 µm length, 8-10 µm breadth, and 11 or 12 striae in 10 µm, and considered that the only difference between this taxon and Cymbella tumidula var. tumidula was the shape of the ends. Although in poor condition, in preparation 1603 we did not find differences between the shape of the valvar ends of the variety salinarum and the nominate variety. However, Cymbella tumidula var. salinarum has higher breadth values compared to the type population of Cymbella tumidula var. tumidula , even in populations of this taxon as recorded by Krammer (2002) from Falaise where initial and post initial cells were found. Moreover, the occurrence of Cymbella tumidula var. salinarum has been restricted to brackish waters.

Krammer (2002, Fig. 25: 13) provided the illustration of an individual of the type of Cymbella salinarum . The individual represented by him (Krammer 2000) was similar to Cymbella tumidula var. tumidula . However, it was larger and had only one isolated pore, differing from Cymbella tumidula , which has more than two isolated pores (Figs 50-56 ). Thus, in contrast to Krammer (2002), who treated Cymbella salinarum at the specific level, we consider this taxon at the infraspecific rank as did Cleve (1894).

Figures

Figures 43 - 63. Cymbella tumidula species complex 43 Original illustration provided by Grunow in Schmidt (1875, Pl. 9, Fig. 33), lectotype, here designated 44 - 49 Cymbella tumidula var. tumidula, specimens from Trieste in preparation BM 18543 49 Epitype, here designated 50 - 56 Cymbella tumidula var. tumidula [Cymbella affinis sensu Krammer (2002)], specimens from Trieste in preparation 1131 G IOK 54 Isolectotype, designated here 57 - 63 Cymbella tumidula var. procera (Krammer) W. Silva, specimens from Serbia in preparation 714 IOK, holotype 57 Lectotype, designated here. Scale bar: 10 µm.