• Category
  • Length Range
    6–21 µm
  • Width Range
    2.1-2.9 µm
  • Striae in 10 µm
    21-23

Identification

Description

Cells have a solitary growth habit. One plastid is present in living cells. Frustules are monoraphid with a concave raphe valve and convex rapheless valve. Valves are linear or linear-elliptical with rounded, slightly drawn-out, or slightly capitate ends, 6-21 (usually 7-17) µm in length. The terminal and central external raphe ends are slightly expanded, no terminal fissures are present. Internally, the central raphe ends are deflected to opposite sides. The striae are parallel throughout both valves. The striae consist of two rows of areolae, with exceptions. At the valve margin the number of rows of areolae is often reduced to one. At the sternum and ends, the number of rows of areolae is often three. An asymmetrical hyaline area is present in the central part of both valves. One row of elongated areolae is present on the valve mantle; the row is continuous on the rapheless valve and interrupted at the apices of the raphe valve. External openings of the areolae are circular, oval, or irregular in shape, more or less isodiametric, approximately 50-90 nm across and not occluded. Internal openings of the areolae are elliptical occluded by hymens. The hymens are perforated by small pores, which are approximately 5-10 nm wide and 5-20 nm long. Internally, the interstriae are raised, so that striae appear as shallow chambers. The girdle bands are unornamented and open.

Autecology

Original Description

Schalen linear-Ianzettlich mit breit gerundeten Enden und oft leicht aufgetriebener Mitte. Die kurzen Stücke elliptisch. 7-20 µm lang, 2-2,8 µm breit. Streifung auf beiden Schalen nur sehr wenig strahlend, in der Mitte meist unterbrochen, grob, etwa. 24 Streifen in 10 µm. Raphe sehr zart, gerade. Längsarea schmal, in der Mitte meist zu einer breiten Querbinde erweitert. - Verwandt mit A. nodosa, von der sie sich durch die geringe Breite und die viel feinere Streifung unterscheidet. - Vorkommen: In 16 Proben mit pH: 6,8-6,9. Vor allem in allen Proben aus Moosrasen und von Felswänden in Saanatunturi und Jehkatstunturi.

  • Basionym
    Achnanthes kriegeri
  • Author
    Krasske 1943
  • Length Range
    7–20 µm
  • Width
    2-2.8 µm
  • Striae in 10µm
    24

Original Images

Achnanthes kriegeri orig illus
Achnanthes kriegeri orig descr
Original text and images reproduced with permission by Deutschen Botanischen Gesellschaft.

EMAP Assessment

EMAP Distribution

A Kreigeri 10
Map 10

Response Plots

A Kriegeri

Cite This Page

Potapova, M. (2009). Achnanthidium kriegeri. In Diatoms of North America. Retrieved June 18, 2018, from https://diatoms.org/species/achnanthidium_kriegeri

Responses

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