Gomphonema cf. pseudopusillum Reichardt

Kulikovskiy, Maxim S., Kociolek, John P., Solak, Cüneyt N. & Kuznetsova, Irina, 2015, The diatom genus Gomphonema Ehrenberg in Lake Baikal. II. Revision of taxa from Gomphonema acuminatum and Gomphonema truncatum-capitatum complexes, Phytotaxa 233 (3), pp. 251-272 : 257

Gomphonema cf. pseudopusillum Reichardt ( Figs 107–118 )

Valves heteropolar, clavate, gibbous and biconstricted. Headpole is cuneate, basal part is elongately cuneate, gradually narrowing to the footpole, usually with almost straight margins. Apical inflations are slightly wider than the mid-inflation or the same breadth. Marginal undulations are evident. Length: 20.0–31.3 μm, breadth: 4.7–6.0 μm. Striae parallel to slightly radiate in the center, more strongly radiate at the footpole, 11–12 in 10 μm. Axial area distinct, narrow. Central area small, one striae in central part is shorter. Stigma isolated and distinct.

Observations: —This population is characterized by a proportionately more slender shape than G. pseudopusillum . We believe that the specimens identified as G. pseudopusillum in Metzeltin et al. (2009: pl. 165, figs 11–16) actually belong to the taxon shown here. More research is needed to decide whether to separate these populations out into a separate species.

Figures

FIGURES 88–118. LM. 88–106. Gomphonema pseudopusillum. 107–118. Gomphonema cf. pseudopusillum. Scale bar = 10 μm.