• Category
  • Length Range
    8.0–14.0 µm
  • Width Range
    3.5–5.0 µm
  • Striae in 10 µm
    24–28

Identification

Description

Valves are elliptic to elliptic-lanceolate. The raphe valve has a linear axial area and a transversely rectangular, to bow-tie shaped central area, which is slightly asymmetric or symmetric. The raphe is straight and lacks terminal raphe fissures. The central and terminal raphe ends are simple. Internally, the central raphe ends curve toward opposite sides. The rapheless valve has a lanceolate axial area and a large, transverse, asymmetric central area with a rimmed depression on the internal valve surface. The striae are radiate on both valves. One row of areolae is present on the mantle of both valves. The external openings of the areolae are mostly isodiametric.

Autecology

Original Description

Diese neue Art wird gleichzeitig aus dem Interglazial von Oberohe in der Lüneburger Heide beschrieben. Es handelt sich also um eine Interglazialform, die im Schaalsee rezent nicht selten ist. Ich fand sie insgesamt in 13 Proben im Zarrentiner Becken, Rethwiesentief, Küchensee von Zecher, Niendorfer See, Techiner See und Borgsee, und zwar mit Ausnahme des Niendorfer Sees, wo sie im Sediment gefunden wurde, ausschlieβlich im Litoral auf verschiedenem Substrat. Sie gehört zu den Arten mit hufeisen-förmigem Fleck an einem Rande der raphenlosen Schale, der aber sowohl bei den fossilen Exemplaren von Oberohe als auch bei den rezenten oft recht matt gezeichnet ist. Die Länge der Schaalseeformen betrug etwa 7–15 μ, ihre Breite 4–5 μ.

  • Basionym
    Achnanthes lauenburgiana
  • Author
    Hust. 1950
  • Length Range
    7–15 µm
  • Width
    4–5 µm

Original Images

Achnanthes lauenburgiana orig illus
Achnanthes lauenburgiana orig descr

EMAP Assessment

EMAP Distribution

Psammothidium Lauenburgianum 40 Copy
Map 40

Response Plots

Psammothidium Lauenburgianum Copy

Cite This Page

Hamilton, P, and Potapova, M. (2010). Psammothidium lauenburgianum. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/psammothidium_lauenburgianum

Responses

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