Eunotia richbuttensis

Furey, Lowe and Johansen 2011      Category: Eunotioid
BASIONYM: Eunotia richbuttensis Furey, Lowe and Johansen 2011

Eunotia rhomboidea

 

Eunotia rushforthii

LM scalebar = 10 µm = 40 pixels.



Observations

Contributor: Paula Furey - March 2011
Length Range: 20-59 µm
Width Range: 7.3-9.9 µm
Striae in 10 µm: 10-14 at the center of the valve, 12-16 at the ends

Description

The ventral margin is only slightly concave, and often nearly straight. The dorsal margin is convex and slightly biundulate in larger valves. The dorsal margin becomes nearly flat, or even convex in the smallest valves. The ends are bluntly rounded and slightly set off by a gradual change in slope of the dorsal margin. Helictoglossae are visible under the LM. One apical rimoportula, distal to the helictoglossa is present near the ventral margin, with a prominent external pore (visible in SEM). The raphe extends from the helictoglossa (15-25% of the length of the valve), with the distal ends curved and clearly visible in the LM. Striae are mostly parallel and curve toward the apices beginning at the helictoglossa. The striae on the dorsal margin are often irregular and shortened. Areaolae within a stria are 34-36 in 10 µm. The internal openings of the areolae are aligned in the bottom of a narrow groove in the inner valve surface (SEM).



Original Description

Basionym: Eunotia richbuttensis
Author: Furey, Lowe and Johansen 2011
Length Range: 20-59 µm
Width Range: 7.3-9.9 µm
Striae in 10 µm: 10-14 in the center valve, 12-16 at the ends, puncta 34-36

Original Description

Valves only slightly concave to nearly straight on ventral margin, convex on dorsal margin, slightly biundulate in longer valves, becoming almost flat, and finally simply convex in smallest valves, 20 – 59 (64) μm long, 7.3 – 9.9 μm wide. Ends bluntly rounded, slightly set off by a gradual change in slope of the dorsal margin. Helictoglossae visible under the light microscope. Rimoportula at one end of valve, distal to the helictoglossa, near ventral margin, with a prominent external pore. Raphe extending from helictoglossa 15 – 25% of the length of the valve, with distal ends curved and clearly visible in the light microscope. Striae mostly parallel, curved towards apices beginning at the helictoglossa, often with a few irregular shortened striae on the dorsal margin, 10 – 14 in 10 μm in the valve center, 12 – 16 in 10 μm near the valve apices. Puncta 34 – 36 in 10 μm.

Original Images


Cite This Page:
Furey, P. (2011). Eunotia richbuttensis. In Diatoms of the United States. Retrieved April 18, 2014, from http://westerndiatoms.colorado.edu/taxa/species/eunotia_richbuttensis

Species: Eunotia richbuttensis

Contributor: Paula Furey

Reviewer: Sam Rushforth

Citations

Furey, P.C., Lowe, R.L. and Johansen, J.R. (2011). Eunotia Ehrenberg (Bacillariophyta) of the Great Smoky Mountains National Park, USA. Bibliotheca Diatomologica 56: 1-134.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)

NADED ID:

Autecology Discussion

Eunotia richbuttensis has been found in low abundance, epiphytic on bryophytes, in first through forth order streams throughout the Great Smoky Mountains National Park, especially in the Big Creek watershed.

Images

Type locality: Big Creek in the Big Creek watershed, Great Smoky Mountains National Park, Cocke County, Tennessee.

Credit/Source: Paula C. Furey