Cocconeis rugosa
Sovereign 1958 Category: Monoraphid
BASIONYM: Cocconeis rugosa Sovereign 1958
LM scalebar = 10 µm = 40 pixels.
Observations
Contributor: Pat Kociolek - February 2011
Length Range: 19-65 µm
Width Range: 12-55 µm
Striae in 10 µm: 19-23
Description
Valves are broadly elliptical. The raphe valve has a straight, filiform raphe that becomes slightly dilated towards the center. The entire margin of the valve is bordered by a hyaline rim. The axial area is very narrow, and broadens slightly to form a small, irregularly-shaped central area. Striae are distinctly punctate (areolae within a stria number about 19-23/10 µm) and are radiate. The striae are interrupted at the poles, and in larger specimens along a longer stretch, by narrow, irregular lines that are located on both sides of the axial area. The rapheless valve is flexed about the apical axis. The axial area is very narrow, and the central area is small or lacking. Striae are coarsely punctate.
This species is an endemic to the Pacific Northwest.
Original Description
Basionym: Cocconeis rugosa
Author: Sovereign 1958
Length Range: µm
Striae in 10 µm:
Original Description
Cocconeis rugosa sp. nov. Pl. III, Figs. 34, 35. Valvae late ellipticae, convexae, 18-63 μ longae, 12-52 μ latae ; rhaphovalva rhaphe directa filiformi, area axiali angustissima, area centrali parva irregulariter definita; striae transapicales radiantes 19-23 in 10 μ, distincte punctatae, puncta etiam 19-23 in 10 μ, praecipue ad polos versus area hyalina longitudinali interruptae ; areovalva area axialis angustissima, area centrali minima, striae transapicales radiantes, 19-20 in 10 μ, distincte punctatae, series punctorum longitudinales paulo remotiores quam striae transapicales, irregulariter undulatae.
Original Images
Cite This Page:
Kociolek, P. (2011). Cocconeis rugosa. In Diatoms of the United States. Retrieved May 22, 2013, from http://westerndiatoms.colorado.edu/taxa/species/cocconeis_rugosa
Species: Cocconeis rugosa
Contributor: Pat Kociolek
Reviewer: Marina Potapova
Image Credit: Pat Kociolek
- Valves broadly elliptical
- Striae on raphe valve interrupted by narrow, irregular hyaline lines on both sides of the axial area
Valves are broadly elliptical. The entire margin of the raphe valve is bordered by a hyaline rim. The striae are interrupted at the poles by narrow, irregular lines that are located on both sides of the axial area.
Compare
Cocconeis rugosa is differentiated from C. klamathensis by the nature of the hyaline lines on either side of the axial area on the raphe valve. In C. rugosa, the lines are indistinct, not as defined or even as in C. klamathensis. Valves of C. rugosa are less arched than those of C. klamathensis.
Cocconeis klamathensis
Citations
Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.
Sovereign, H.E. (1958). The diatoms of Crater Lake, Oregon. Transactions of the American Microscopical Society 77(2):96-134.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 16029