• Category
  • Length Range
    21-33 µm
  • Width Range
    12.1-14.4 µm
  • Striae in 10 µm
  • Synonyms
    Neidium ladogense var. densestriatum (Østrup) Foged



Valves are elliptic, tapering to cuneate or slightly apiculate apices. The axial area is narrow and linear. The central area is transapically elliptic, and ghost striae may be visible. The raphe is linear, with distinctly straight proximal raphe ends. Only in occasional specimens are the proximal raphe ends slightly deflected. Longitudinal canals are relatively wide and positioned almost on the valve margin. Striae are distinctly punctate and slightly radiate to parallel throughout. Areolae are punctate, numbering 24-28 in 10 μm.


Neidium densestriatum prefers slightly acidic freshwater lakes, and tends to occur with Frustulia and Brachysira throughout the northeast U.S. (Stachura-Suchoples et al. 2004). This species has also been reported from rivers in east Canada (Lavoie et al. 2008) and from low alkalinity lakes in New York (as N. ladogense v. densestriatum by Camburn and Charles 2000, Pl 21, Fig 6.

We confirmed N. densestriatum from reference-quality streams throughout the southeast U.S. (EPA National Streams Assessment Program).

Original Description

– ladogensis Cl. var. densestriata var. nova. Tab. nost. I, Fig. 4.

Long. 28 μ, Lat. 14 μ. Str. Minime 22 in 10 μ.

Valva late-lanceolata, apicibus subtruncatis, linea infra-marginali duplice vel triplice instructa. Raphe area hyalina angustissima, media in parte valvae in aream centralem parvam dilatata, cincta. Striis delicatis, radiantibus.

J: Krog Sø Ld., Madum Sø A. F., Raabjerg Mile E. W., Skagen E. W., Thorsø E. W., Utofte Bs. Alt Ferskv.

Denne Art har jeg kun fra Jylland, hvor den forekommer I ringe Maengde I de naevnte Prøver. Den afviger fra Hoved-arten vaesenligt ved den taettere Stribning og ved at have flere inframarginale Linier. Cal. ladogensis Cl. Syn. I, 62. Cl. Diat. Finl. Tab. II, fig. 3 er en Ferskvandsart fra: “Ladoga, on the surface of the lake.

  • Basionym
    Caloneis ladogensis var. densestriata
  • Author
    Østrup 1910
  • Length Range
    28 µm
  • Width
    14 µm
  • Striae in 10µm

Original Images

Caloneis Ladogensis Var Densestriata Original Illus
Caloneis ladogensis var. densestriata orig descr

Cite This Page

Polaskey, M. (2018). Neidium densestriatum. In Diatoms of North America. Retrieved June 21, 2024, from https://diatoms.org/species/neidium-densestriatum


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Neidium densestriatum 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.