(Cleve) Lange-Bertalot 1999 Category: Symmetrical biraphid
BASIONYM: Navicula subtilissima Cleve 1891
SYNONYM(S): Kobayasia subtilissima (Cleve) Lange-Bertalot 1996
Contributor: Loren Bahls - March 2012
Length Range: 23-27 µm
Width Range: 5.1-6.0 µm
Striae in 10 µm: 36-40, 30-36 in center
Valves are linear-lanceolate with convex sides and short, capitate apices. Apices are about one-half the width of the valve. Valve length-to-width ratio ranges from 4.0 to 4.7. The axial area is narrow and nearly linear. The central area is small and elliptical and bordered by alternately long and short striae. The raphe is filiform with a slight "kink" (SEM) about halfway to the apices. Proximal raphe ends are straight and slightly expanded. Distal raphe ends are strongly curved towards the secondary side, where Voigt discontinuities are evident in SEM. In LM, striae are easy to distinguish only in the central area. Striae are radiate, becoming convergent near the apices. Striae are composed of irregular series of dots and dashes which form jagged and faint longitudinal lines. The striae stop short of the valve mantle, where a hyaline line completely encircles the valve along the margins (SEM).
Basionym: Navicula subtilissima
Author: Cleve 1891
Length Range: 32 µm
Width Range: 5 µm
Striae in 10 µm: 40-45
Cleve, P.T. (1891). The Diatoms of Finland. Actas Societas Pro Fauna et Flora Fennica 8 (2): 1-68.
Kobayasi, H. and Nagumo, T. (1988). Examination of the type materials of Navicula subtilissima Cleve (Bacillariophyceae). The Botanical Magazine, Tokyo 101: 239-253.
Lange-Bertalot, H. (1996). Kobayasia bicuneus gen. et spec. nov. In: Iconographia Diatomologica, Annotated Diatom Micrographs (H. Lange-Bertalot, ed.), Vol. 4, pp. 277-287, Koeltz Scientific Books, Konigstein.
Lange-Bertalot, H. (1999). Kobayasiella nov. nom. ein neuer Gattungsname fur Kobayasia Lange-Bertalot 1996. In: Iconographia Diatomologica, Annotated Diatom Micrographs (H. Lange-Bertalot, ed.), Vol. 6, pp. 272-275, A.R.G. Gantner Verlag K.G., Vaduz.
Navicula subtilissima was described by Cleve from material collected in Lake Imandra, Russian Lapland, at approximately 68 degrees north latitude. Fallu et al. (2000) reported this taxon from lakes in northern Québec and Labrador. In the United States, Stoermer et al. (1999) reported Kobayasiella subtilissima (as Kobayasia subtilissima) from the Great Lakes. We have six records for this species in the Montana Diatom Collection, from California, Idaho, Montana, and Wyoming. One of these records is for Drosera Pond on the Indian Meadows Research Natural Area, Helena National Forest, Montana, where it occurs in association with K.micropunctata, K. okadae, and K. parasubtilissima. Here the pH measures 8.46 and specific conductance measures 19 µS/cm.
Collecting diatoms from Sphagnum moss at Drosera Pond, Indian Meadows Research Natural Area, Helena National Forest, Montana. Drosera Pond is home to Kobayasiella subtilissima and three other spcecies in this genus.
Credit/Source: John Pierce