• Category
  • Length Range
    18–52 µm
  • Width Range
    1.9–2.3 µm
  • Striae in 10 µm
  • Reported As
    Eunotia curvata var. subarcuata (Camburn & Charles 2000, Pl. 12, Figs 10-16)



Valves are slender, arcuate and lightly silicified, giving them a faint appearance. Margins are parallel throughout the valve, that is, valve width is constant. Apices are rounded, indistinctly subcapitate and helictoglossae are small. Distal raphe fissures are extremely short, terminating in helictoglossae, and practically invisible in LM. Striae are parallel and perpendicular to the valve margins, sometimes slightly radiate near the apices, but not always well visible due to light silicification. One rimoportula is present per valve, situated near the helictoglossa at the apex (not visible in LM). Both internal and external expression of the areolae are rounded and open.


In North America, with E. mucophila was observed in acidic lakes of Acadia National Park, Maine (personal observations), the Adirondacks Mountains of New York (Camburn and Charles 2000), Cape Cod, Massachusetts (Siver et al. 2005) and South Carolina (Gaiser and Johansen 2000). This species is also found in peat bogs and dystrophic lakes of the Holarctic region (details in Lange-Bertalot et al. 2011, p. 165).

Original Description

Eunotia bilunaris var. mucophila Lange-Bertalot, Nörpel et Alles nov. var. TafeI, V, Fig. 12-21

Konspezifisch sind: Eunotia lunaris var. subarcuata Nägeli ex Kützing sensu auct. nonnull., Eunotia naegelii Migula (syn. E. alpina Nägeli) sensu auct. nonnuIl.

Beschreibung und Abgrenzung der Varietät:

Varietas nova similitudinem habet cum var. bilunaris sed angustior ad latitudinem, 1,9-2,7(3) µm, et striis transapicalibus densior positis, 20-28 in 10 µm. Fissura terminalis raphae non recurvata ad proximam partem vaIvae. Area terminalis raphae, id est linea hyalina in planitie interna valvarum, abest. Habitat (semper?) in muco algarum diversarum, exempli causi Batrachospermum et Sirodotia.

Holotypus: Botanisches Institut der Universität Frankfurt am Main, Coll. Lange-Bertalot, Probebezeichnung: Alles & Nörpel 010.0.C-5 vom 18.7.89 (Tafel V, Fig. 17-20). Fundort des Holotypus: Schurmsee im Schwarzwald, Rotalgen (Sirodotia).

Schalenumrisse im Zuge des Entwicklungszyclus grudsätzlich ähnlich wie bei den meisten Sippen, die der Nominatvarietät zugeordnet werden, jedoch mit stets geringerer Breite. Länge: 10 bis über 70 µm; Breite: 1,9 bis 2,7(3) µm.

Rücklaufende Terminalspalten im LM niemals erkennbar, im REM einen kurzen Bogen bildend, der nur ansatzweise einen Rücklauf andeutet. Eine hyaline Area unterhalb der Terminalspalte auf der Schaleninnenfläche ist allenfaIIs andeutungsweise erkennbar. Striae: 20-28/10 µm.

  • Basionym
    Eunotia bilunaris var. mucophila
  • Author
    Lange-Bert., Nörpel-Schempp and Alles in Alles et al. 1991
  • Length Range
    10–70 µm
  • Width
    1.9–2.7(3) µm
  • Striae in 10µm

Original Images

Eunotia bilunaris var. mucophila orig illus
Eunotia bilunaris var. mucophila orig illus 2
Eunotia Bilunaris Var Mucophila Orig Descr

Citations & Links



  • Index Nominum Algarum
  • North American Diatom Ecological Database
    NADED ID: 33267

Cite This Page

Veselá, J. (2017). Eunotia mucophila. In Diatoms of North America. Retrieved May 18, 2024, from https://diatoms.org/species/eunotia_mucophila


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Eunotia mucophila from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.