• Category
  • Diameter
    3.7-6.5 µm
  • Striae in 10 µm
    22-24
  • Synonyms
    Cyclotella pseudostelligera Hust. 1939

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 in nutrient-rich midwestern streams and lakes (Stoermer and Yang 1969, Houk et al. 2010) and oligo- to mesotrophic lakes in Europe (Krammer and Lange-Bertalot 1991, Peeters and Ector 2017) and North America.

The taxon is reported common in lakes in Quebec (Fallu et al. 2000), in softwater lakes in Wood Buffalo National Park (Moser et al. 2004), in sediment core material from Lakes Saint-Francois and Saint-Louis in the St. Lawrence Riverway (Reavie and Smol 1998), in many habitat types in the Laurentian Great Lakes, especially Lakes Erie and Ontario (Bramburger et al. 2017, Reavie and Kireta 2015), and from inland lakes in Montana, Colorado, northwest Canada (Bahls 2021). In the Great Lakes Network National Parks, it is especially common in Grand Sable Lake in Pictured Rocks National Lakeshore (Edlund et al. 2011).

Environmental optima are variable for this taxon and include 40 µg/L TP and 25 µg/L Cl (Reavie and Kireta 2015), 14 µg/L TP and 10.92 µg/L SiO2 (Moser et al. 2004), and conductivity optimum of 185.4 µS/cm and suspended solids optimum of 8.3 mg/L from riverine samples (Reavie and Smol 1998).

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

Citations & Links

Citations

Links

Updates

Dec 14, 2023 - Addition of Autecology

From 2015 until 2023 the autecological information on this taxon page was limited. As of this update, information on ecology, biogeography, and environmental optima have been added. - Mark Edlund

Cite This Page

Lowe, R., Edlund, M., Spaulding, S., Allen, L., Bishop, I. (2015). Discostella pseudostelligera. In Diatoms of North America. Retrieved February 22, 2024, 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.