Eunotia cataractarum
Furey, Lowe and Johansen 2011 Category: Eunotioid
BASIONYM: Eunotia cataractarum Furey, Lowe and Johansen 2011
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Paula Furey - February 2011
Length Range: 11-21 µm
Width Range: 3.1-3.9 µm
Striae in 10 µm: 15-20 in the center valve, 16-19 at the ends, puncta 44-50
Description
Valves are concave on the ventral margin, sometimes with scarcely visible swellings on the ventral margin, marking the position of the proximal raphe ends. Valves have a slightly convex, flattened dorsal margin. The apices are set off dorsally by a fairly steep sloping shoulder. Apices are capitate and rounded. Helictoglossae are not visible in the LM. One apical rimoportula at the center of the apex, with a distinct external pore (visible in SEM). Striae are parallel to slightly radiate.
Original Description
Basionym: Eunotia cataractarum
Author: Furey, Lowe and Johansen 2011
Length Range: 11-21 µm
Width Range: 3.1-3.9 µm
Striae in 10 µm: 15-20 in the center valve, 16-19 at the ends, puncta 44-50
Original Description
Valves concave on the ventral margin, sometimes with scarcely visible swellings marking the position of the proximal raphe ends. Slightly convex flattened dorsal margin, with apices set off dorsally by a fairly steep sloping shoulder. Apices capitate, rounded. Helictoglossae not visible in the light microscope. Rimoportula at one end of valve, at the center of the apex, with a distinct external pore. Striae parallel to slightly radiate, 15 – 20 in 10 μm in the valve center, 16 – 19 in 10 μm at the apices. Puncta 44 – 50 in 10 μm.
Original Images
Cite This Page:
Furey, P. (2011). Eunotia cataractarum. In Diatoms of the United States. Retrieved May 22, 2013, from http://westerndiatoms.colorado.edu/taxa/species/eunotia_cataractarum
Species: Eunotia cataractarum
Contributor: Paula Furey
Reviewer: Marina Potapova
Image Credit: Paula Furey
- Ventral margin concave
- Dorsal margin slightly convex
- Apices capitate
- Striae parallel to slightly radiate
- One apical rimoportula
Valves with a concave ventral margin. The dorsal margin is slightly convex and set off dorsally by a steep sloping shoulder. Apices are capitate and rounded. Striae are parallel to slightly radiate. One apical rimoportula at the center of the apex (visible in SEM), with a distinct external pore. .
Compare
Eunotia cataractarum belongs to the E. exigua complex based on size, striae density and valve constricted before the apices. The ventral margin of E. cataractarum is not as strongly concave as that of other members of E. exigua species complex. Furthermore, the apices of E. cataractarum are more rounded and not as strongly dorsally recurved compared with E. exigua. Finally, the shoulder is steeper in E. cataractarum valves compared with the more gradual slope in the E. exigua valves. While E. cataractarum is similar to E. varioundulata, the dorsal margin of E. caracatarum is flatter and lacks undulations. The dorsal margin of E. cataractarum is not straight as that of E. orthohedra.
Eunotia orthohedra
Eunotia exigua
(Bréb.) Rabh.
Eunotia varioundulata
Nörpel-Schempp and Lange-Bertalot
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 cataractarum is commonly found in the epilithon or epiphytic on bryophytes at waterfalls, and occasionally in streams in the Great Smoky Mountains National Park.