• Category
  • Diameter
    3.7-6.5 µm
  • Striae in 10 µm
    22-24

Identification

Description

Valves may be flat, or may have a convex or concave center. Valves have a distinct central area with a stellate or “floral” pattern of elongate or puncta-like areolae. The central area is surrounded by a marginal ring of radiate striae. The radiate striae may be bifurcated by ribs, or may have an irregular radiate pattern due to insertion of shorter striae near the valve margin. The marginal fultoportulae have expanded, hood-like external projections. These structures may be spaced on every 3 to 7 ribs. The marginal fultoportulae are best observed by fine focusing (optically dissecting) the valve. The central stellate areolae may not be present on all specimens; specimens with such morphology are sometimes referred to Discostella woltereckii Hustedt (Belcher et al. 1966).

Autecology

This species is of wide-spread occurrence and is common in the summer plankton nutrient-rich of midwestern streams.

Original Description

Cyclotella pseudostelligera nov. spec. Schalen kreisrund, 7-8 µ im Durchmesser, nur wenig konzentrisch gewellt, fast flach. Mittlefeld 1/2 des Schalendurchmessers, mit einem zentralen Ring winziger Punkte oder kurzer Striche und einem isolierten Punkt in der Mitte dieses Ringes. Randzone zart radial gestreift, Streifen etwa 18 in 10 µ, ohne Höcker oder stärkere Rippen, aber innerhalb des Schalenrand des mit einem Kranz auffallend kräftiger Dornen. Fig. 1, 2.

  • Basionym
    Cyclotella pseudostelligera
  • Author
    Hust. 1939
  • Length Range
    7-8 µm
  • Striae in 10µm
    18

Original Images

Pseudostelligera Pic
Pseud Description1

EMAP Assessment

EMAP Distribution

Discostella Pseudostelligera   Hustedt   Houk Et  Klee 3
Map 3

Response Plots

Discostella Pseudostelligera   Hustedt   Houk Et  Klee

Citations & Links

Citations

Links

Cite This Page

Lowe, R. (2015). Discostella pseudostelligera. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/discostella_pseudostelligera

Responses

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