(Skvortzow) Lange-Bertalot 1999 Category: Symmetrical biraphid
BASIONYM: Anomoeoneis okadae Skvortzow 1938
SYNONYM(S): Kobayasia okadae (Skvortzow) Lange-Bertalot | Navicula okadae (Skvortzow) Nagumo & Kobayasi
REPORTED AS: Navicula hoefleri (Hustedt 1961-1966, p. 97, fig. 1244) | Navicula hoeflerii (Krammer & Lange-Bertalot 1986, p. 183, fig. 79: 28)
Contributor: Loren Bahls - December 2011
Length Range: 31-37 µm
Width Range: 7-9 µm
Striae in 10 µm: 22-24 (middle), 36-38 (ends)
Valves are linear-lanceolate with short, capitate apices. Apices are about one-half the width of the valve. The axial area is narrow and nearly linear, the narrowest point being where the valve margins constrict to form the apices. From this narrow point the axial area flares abruptly towards the valve apex, and, in the other direction, very gradually towards the central area. The central area is small, barely wider than the axial area, and elliptical in shape. The raphe is filiform. A section of each external raphe branch becomes indistinct about mid way between the valve center and the apex. Proximal raphe ends are straight and lie in spathulate depressions, which make them appear expanded in LM. Distal raphe ends are strongly curved towards the secondary side, where prominent Voigt discontinuities are evident in SEM. Striae are radiate, becoming convergent and more closely spaced near the apices. Striae are interrupted by longitudinal hyaline lines, the pair of which form a lanceolate shape within the valve. These hyaline lines terminate near the valve apices, where the striae are not interrupted. The striae also stop short of the valve mantle, where another hyaline line completely encircles the valve along the margins.
Basionym: Anomoeoneis okadae
Author: Skvortzow 1938
Length Range: 28.9-30.6 µm
Width Range: 6.8 µm
Striae in 10 µm: 20-22 (middle), 25-30 (ends)
Camburn, K.E. and Charles, D.F. (2000). Diatoms of Low-Alkalinity Lakes in the Northeastern United States. Academy of Natural Sciences of Philadelphia, Special Publication 18, 152 pp.
Hustedt, F. (1966). Die Kieselalgen Deutschlands, Österreichs und der Schweiz unter Berücksichtigung der übrigen Länder Europas sowie der angrenzenden Meeresgebiete. 3.Teil. Reprint 1977 by Otto Koeltz Science Publishers, Koenigstein, Germany. 816 pp.
Krammer, K. and Lange-Bertalot, H. (1986). Bacillariophyceae. 1. Teil: Naviculaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/1. Gustav Fisher Verlag, Jena. 876 pp.
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.
Lange-Bertalot, H. and Metzeltin, D. (1996). Indicators of oligotrophy - 800 taxa representative of three ecologically distinct lake types, Carbonate buffered - Oligodystrophic - Weakly buffered soft water. Lange-Bertalot, H. (ed.), Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 2. Ecology, Diversity, Taxonomy. Koeltz Scientific Books. Königstein, Germany, 2:390 pp.
Nagumo, T. and Kobayasi, H. (1990). Observations on Navicula okadae (Skvortzow) comb. nov. (Bacillariophyceae). Diatom Research 5 (2): 367-372.
Skvortzow, B.W. (1938). Diatoms collected by Mr. Yoshikazu Okada in Nippon. I. Mountain bog diatom flora from Prov. Shinano. Journal of Japanese Botany 14: 52-65.
Kobayasiella okadae was found among moss and roots of vascular plants in two floating-mat fens in western Montana. Here the pH was 6.77 and 8.46, and specific conductance measured 19 and 257 µS/cm. Elsewhere in the United States, K. okadae has been reported (as Navicula hoefleri) from a few oligotrophic and low conductivity lakes in New York (Camburn & Charles 2000) and Wisconsin (Diatom Paleolimnology Data Cooperative, Patrick Center, The Academy of Natural Sciences). Kobayasiella okadae is typically found together with K. parasubtilissima and K. subtilissima in slightly acid waters in arctic to subarctic zones, and in temperate regions (Nagumo & Kobayasi 1990). Krammer & Lange-Bertalot (1986) reported K. okadae (as Navicula hoeflerii) from Scandinavia and the Alps. Lange-Bertalot & Metzeltin (1996) found K. okadae (reported as Naviculadicta hoefleri) in a Finnish lake that has low levels of conductance and inorganic nutrients and a high level of humic acid.
Drosera Pond, Indian Meadows Research Natural Area, Helena National Forest, Montana: home of Kobayasiella okadae.
Credit/Source: Loren Bahls