Encyonopsis stafsholtii

Bahls 2013      Category: Asymmetrical biraphid
BASIONYM: Encyonopsis stafsholtii Bahls 2013

REPORTED AS: Encyonopsis cesatii (Lange-Bertalot and Genkal 1999, p. 226, pl. 56, fig. 6) | Cymbella cesatii (Tynni 1978, p. 27 [in part], pl. X, figs. 80 a, b [not figs. 79, 81]) | Cymbella cesatii (Krammer and Lange-Bertalot 1986, p. 325 [in part], pl. 134, fig. 6 [not figs. 4, 5, 7-13]) 

Encyonopsis neerlandica

 

Encyonopsis subminuta

LM scalebar = 10 µm = 80 pixels.



Observations

Contributor: Loren Bahls - May 2013
Length Range: 24.9-44.7 µm
Width Range: 5.1-6.3 µm
Striae in 10 µm: 22-25

Description

Valves are rhombic-lanceolate and slightly dorsiventral. Apices are gradually protracted, narrowly subrostrate and deflected ventrally. The axial area is narrow. The central area is asymmetric, rounded on the dorsal side and delimited by 1 to 3 irregularly shortened striae on the ventral side. The raphe is lateral, becoming filiform at the proximal and distal ends. Proximal raphe ends are weakly expanded and deflected dorsally. Distal raphe fissures are hooked toward the ventral side. Striae are radiate throughout.



Original Description

Basionym: Encyonopsis stafsholtii
Author: Bahls 2013
Length Range: 24.9-44.7 µm
Width Range: 5.1-6.3 µm
Striae in 10 µm: 22-25

Original Description

Valves rhombic-lanceolate, slightly dorsiventral. Apices gradually protracted, narrowly subrostrate, deflected ventrally. Valve length 24.9–44.7 µm; valve width 5.1–6.3 µm. Axial area narrow. Central area asymmetric, rounded on the dorsal side, defined by 1 to 3 irregularly shortened striae on the ventral side. Raphe lateral, filiform at the proximal and distal ends. Proximal raphe ends weakly expanded, deflected dorsally. Distal raphe fissures hooked toward the ventral side. Striae radiate, 22–25 in 10 µm.

Original Images


Cite This Page:
Bahls, L. (2013). Encyonopsis stafsholtii. In Diatoms of the United States. Retrieved October 23, 2014, from http://westerndiatoms.colorado.edu/taxa/species/encyonopsis_stafsholtii

Species: Encyonopsis stafsholtii

Contributor: Loren Bahls

Reviewer: Pat Kociolek

Citations

Bahls, L. (2013). Encyonopsis from western North America: 31 species from Alberta, Idaho, Montana, Oregon, South Dakota, and Washington, including 17 species described as new. Northwest Diatoms, Volume 5. The Montana Diatom Collection, Helena, 46 pp.

Krammer, K. (1997). Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 2. Encyonema part., Encyonopsis and Cymbellopsis. Bibliotheca Diatomologica 37:1-469.

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. and Genkal, S.I. (1999). Diatoms from Siberia I. Islands in the Arctic Ocean (Yugorsky-Shar Strait). Iconographia Diatomologica 6: 1-292.

Tynni, R. (1978). Über Finnlands rezente und subfossile Diatomeen, X. Geological Survey of Finland, Bulletin 296.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)

NADED ID:

Autecology Discussion

Encyonopsis stafsholtii is widely distributed and locally abundant in lakes of the Northern Rockies. At sites with water quality data, pH ranges from 7.94 to 9.01 and conductivity from 92 to 171 µS/cm.

Images

Lake McDonald, Glacier National Park, Montana: type locality of Encyonopsis stafsholtii.

Credit/Source: National Park Service webcam