Cymbella affinis var. subcapitata (Krammer) W.Silva, 2015

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 : 5-6

Cymbella affinis var. subcapitata (Krammer) W.Silva comb. nov. Figs 36-42

Basionym.

Cymbella excisa var. subcapitata Krammer, 2002, Diatoms of Europe 3: 159, Figs 10: 14-18.

Holotype.

Preparation 717A IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany.

Lectotype

(designated here). An individual on preparation 717A IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany, represented by Fig. 39 .

Type locality.

Hungary, Balaton.

Valves dorsiventral, dorsal margin broadly convex, ventral margin straight, usually with excision in middle portion; ends barely protracted, rounded, to broadly protracted, subcapitate; length 21.0-31.7 µm, breadth 7.4-9.0 µm, L/B ratio 2.7-4.0; axial area linear-arched, indistinct central area; striae 8-12 in 10 µm, becoming 9-15 towards ends, one isolated pore at end of central striae of ventral side; 26-31 punctae in 10 µm.

Remarks.

Krammer (2002) distinguished this variety from the variety excisa based on the shape of the ends of the valvae. However, he ( Krammer 2002, p. 28) did not provide metric characterizations of this the variety subcapitata , which we observed to agree with the characterizations of Cymbella excisa sensu Krammer (2002), except for the density of striae that was slightly lower in the variety subcapitata .

Specimens designated by Krammer (2002), i.e., the preparation 717A IOK (BRM), were found to belong to more than one taxon. Therefore we designated a lectotype as established in Art. 9.11 of the ICN ( McNeill et al. 2012).

Figures

Figures 29 - 42. Cymbella affinis species complex 29 - 35 Cymbella affinis var. angusta (Krammer) W. Silva, specimens from Croatia in preparation 752 IOK, holotype 29 Lectotype, designated here 36 - 42 Cymbella affinis var. subcapitata (Krammer) W. Silva, specimens from Hungary in preparation 717 IOK, holotype 39 Lectotype, designated here. Scale bar: 10 µm.