Aulacoseira nygaardii

(Camburn) Camburn and Charles 2000      Category: Centric
BASIONYM: Melosira nygaardii Camburn in Camburn and Kingston 1986

Aulacoseira nivaloides


Aulacoseira pusilla

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova | Jonathan English - December 2010
Diameter: 4-11 µm
Mantle Height: 4-19 µm
Rows of areolae in 10 µm: 22-31


Frustules are cylindrical and form short chains. The ratio of the mantle height to valve diameter is close to 1. The mantle has straight sides, but the mantle/valve face junction is rounded. The valve face appears slightly convex in LM, but flat in SEM. Rows of pervalvar areolae are straight, parallel to the pervalvar axis, 22-31 in 10 µm, with 30-42 areolae in 10 μm. The height of the collum is approximately1/2-1/3 of the mantle height. The valve face is plain, but with short radial striae at the periphery. The spines are anchor-shaped, narrow, and originate from every second or third costa. The ringleiste is shallow and bell-shaped in cross-section.

Original Description

Basionym: Melosira nygaardii
Author: Camburn in Camburn and Kingston 1986
Diameter: 5-11 µm
Mantle Height: 4-19 µm
Rows of areolae in 10 µm: 20-22

Original Description

Frustules rectangular in girdle view, valves slightly rounded at the mantle. Valve (5.0) 6.9-11.0 μm in diameter. Pervalvar axis variable in length, (4.0) 7.0-17.0 (19.0) μm. Valve mantle contains striae which are parallel to the pervalvar axis, striae 20-22 in 10 μm. Striae are finely punctate, puncta 25-30 in 10 μm. Sulcus well developed. Periphery of valve face ornamented with a narrow (<1.0 μm) band of radiate striae. Striae ca. 30 in 10 μm. The remaining valve face is unornamented. A row of spines occurs around the circumference of the valve face, a spine is located every 2-3 striae. Spines ca. 1.0-1.5 μm in length

Original Images

Original text and images reproduced with permission by Academy of Natural Sciences of Philadelphia.

Cite This Page:
Potapova, M., and English, J. (2010). Aulacoseira nygaardii . In Diatoms of the United States. Retrieved April 26, 2018, from

Species: Aulacoseira nygaardii

Contributor: Marina Potapova | Jonathan English

Reviewer: Sam Rushforth


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.

Camburn, K.E. and Kingston, J.C. (1986). The genus Melosira from soft-water lakes with special reference to northern Michigan, Wisconsin and Minnesota. In: Diatoms and Lake Acidity, J.P. Smol, R.W. Battarbee, R.B. Davis & J. Meriläinen (eds), Dr W. Junk Publishers, Dordrecht. pp. 17-34.

Siver, P.A. and Hamilton, P.B. (2005). A reevaluation of Aulacoseira nygaardii (Camburn) Camburn & D.F. Charles (Bacillariophyceae): based on scanning electron microscopy of type material. Nova Hedwigia 81: 257-265.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Aulacoseira nygaardii CAS

North American Diatom Ecological Database (NADED)

NADED ID: 10039

Autecology Discussion