Eunotia novaeangliae

J.Veselá and J.R.Johans. 2014      Category: Eunotioid

REPORTED AS: Eunotia incisa (Camburn and Charles 2000, pg. 66, Pl. 13, Fig. 9) | Eunotia incisa "narrow form" (Siver et al. 2005, p. 80, Pl. 26, Fig. 12) | Eunotia sp. aff. incisa (Lange-Bertalot et al. 2011, pg. 336, Pl. 36, Fig. 39) 

Eunotia naegelii


Eunotia nymanniana

LM scalebar = 10 µm = 80 pixels.


Contributor: Jana Veselá - February 2017
Length Range: 15-54 µm
Width Range: 2.0–2.6 µm
Striae in 10 µm: 21–22


Valves are narrow and linear, with straight ventral margin and slightly arcuate dorsal margin. Valves are widest in the center and gradually tapering to the apices. The apices are acute and usually slightly bent to the ventral side. Valve length to width ratio is 7–24. The raphe is relatively long (5–7 μm) and situated mostly on the valve mantle. The helictoglossa at each apex is expanded, into an internal costa across the valve apex and penetrated by a single stria. Costae are clearly visible in LM. One large rimoportula per valve is present, placed centrally at the valve apex, occasionally visible in LM. Striae are parallel throughout the valve becoming slightly radiate at the apices. Areolae are circular and externally occluded, 45–55 in 10 μm. In girdle view, frustules are slender and (3.2–5.2 μm wide) rectangular with rounded edges.

Original Description

Author: J.Veselá and J.R.Johans. 2014
Length Range: 15–54 µm
Width Range: 2.0–2.6 µm
Striae in 10 µm: 21–22

Original Description

In girdle view frustules are rounded-rectangular, slender, and 3.2–5.2 μm wide (Figs 35–39). Valves are linear with straight ventral margin and slightly arcuate dorsal margin, widest in the center and gradually tapering toward the ends throughout the whole length of the valve, with ends often slightly ventrally reflexed; with length to breadth ratio of 7–24:1, 15–54 μm long, 2–2.6 μm wide in the widest part (Figs 1–34). No siliceous protrusions on the valve exterior are present (Figs 40–48). Transition of the valve face towards the ventral valve mantle is sharp (Figs 41–48), whereas the transition is gradual on the dorsal side (Figs 41–48). Raphe is long, extending along the mantle for 5–7 μm, barely coming onto the valve face in subapical position (Figs 40–44, 46–48), and not extending past the helictoglossa. Helictoglossa at each apex is massive, expanded into an internal costa which extends obliquely across the valve apex and is penetrated by a single stria (Figs 49–55), with costae clearly visible in the LM (Figs 1–34). One rimoportula per valve is present (Figs 49, 51, 53–55), centered apically on the valve face, with a large external pore easily distinguishable from the external areolae apertures in SEM (Figs 40–41, 43, 46, 47), occasionally visible in LM (e.g., Figs 1, 9, 10, 32). Striae are parallel throughout the valve (Figs 1–34, 40, 43), slightly radiating at the apices (e.g., Figs 41, 42, 48), 21–22 in 10 μm. Areolae are circular, and externally occluded (Figs 40–46), 45–55 in 10 μm.

Original Images

Cite This Page:
Veselá, J. (2017). Eunotia novaeangliae. In Diatoms of the United States. Retrieved April 19, 2018, from

Species: Eunotia novaeangliae

Contributor: Jana Veselá

Reviewer: David R.L. Burge


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.

Lange-Bertalot, H., Bak, M., Witkowski, A. and Tagliaventi, N. (2011). Eunotia and some related genera. Diatoms of the European Inland Waters and Comparable Habitats. 6: 747 pp.

Siver, P.A., Hamilton, P.B., Stachura-Suchoples, K. and Kociolek, J.P. (2005). Diatoms of North America. The Freshwater Flora of Cape Cod. Iconographia Diatomologica 14: 1-463.

Veselá, J. and Johansen, J.R. (2014). Three new Eunotia (Bacillariophyta) species from Acadia National Park, Maine, U.S.A. Phytotaxa 175(4): 181-200.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)


Autecology Discussion

Eunotia novaeangliae was described from Acadia National Park, Maine (Veselá & Johansen 2014), where it occured in the benthos of acidic and oligotrophic lakes and streams (pH 4.6–5.1, cond. 23–110 μS). It was also collected (although mis- or un-identified) from Big Moose Lake in the Adirondack Mountains region, New York (Camburn & Charles 2000), from lakes on Cape Cod Peninsula, Massachusetts (Siver et al. 2005), and from Canada (Lange-Bertalot et al. 2011). This species is likely more widely distributed on the east coast of North America, especially New England and southeastern Canada.