• Category
  • Length Range
    5.4-17.8 µm
  • Width Range
    2.1-4.0 µm
  • Striae in 10 µm
    25-35 in the middle of raphe valve
  • Synonyms
    Achnanthes eutrophila Lange-Bert.

Identification

Description

Valves are rhombic-elliptical to rhombic-lanceolate. The raphe valve is concave with a linear axial area. The axial area widens slightly in the middle portion of the valve. Terminal raphe fissures are straight. Central raphe endings are slightly expanded externally, and curved to opposite sides internally. The rapheless valve is convex, with a narrow linear axial area widening slightly in the middle. Striae are radiate throughout both valves, 25-35 in 10 µm. A few central striae are more distant from each other. External openings of areolae are rounded or elliptical and transapically elongated. Each stria in the middle part of the valve contains 4-5 areolae.

Autecology

Although formation of mucilagenous stalks was never observed in A. eutrophilum, this species might be able to produce stalk as other Achnanthidium species.

Original Description

Schalen in Umriss regelmässig rhombisch oder rhombisch-elliptisch, bei den grösseren Exemplaren rhombisch-lanzettlisch, mit +/- breit gerundeten, niemals vorgezogen oder kopfig erscheinenden Enden. Länge 4-18 µm, Breite 3-4 µm. R-Schale: Raphe filiform. gerade bis zu den kleinen Terminalporen, niemals mit gekrümmten Terminalspalten. Axialarea schmal- bis linear-lanzettlisch, manchmal zu einer sehr kleinen Zentralarea erweitert. Meistens jedoch ist keine Zentralarea differenziert. Streiffen durchgehend radial, 24-27 in 10 µm. Die zwei mittleren sich gegenüberstehenden Streifen oder auch je zwei bis drei erschinen stärker merkiert und sind weiter entfernt gestellt als die ubrigen. RL-Schale: Zentralarea nicht ausfeprägt, Axialarea und Streifen wie auf der R-Schale.

  • Basionym
    Achnanthes eutrophila
  • Author
    Lange-Bert. 1996
  • Length Range
    4–18 µm
  • Width
    3–4 µm
  • Striae in 10µm
    24-27

Original Images

Achnanthes eutrophila orig illus
Achnanthes eutrophila orig descr

Cite This Page

Potapova, M. (2009). Achnanthidium eutrophilum. In Diatoms of North America. Retrieved July 20, 2018, from https://diatoms.org/species/achnanthidium_eutrophilum

Responses

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