• Category
  • Length Range
    17.8-23.9 µm
  • Width Range
    4.9-5.9 µm
  • Striae in 10 µm
  • Synonyms
    Pinnularia schwabei Krasske 1939
    Biremis schwabei (Krasske) Lange-Bert. 1996
    Pulchella schwabei (Krasske) Krammer 2000
  • Reported As
    Pinnularia schwabei (Krammer and Lange Bertalot 1986 p. 422, Pl. 188, Fig 4-8)



Valves are lanceolate and narrow, with a flat valve face. The valve apices are subrostrate to rostrate. The axial area is linear. The central area is elliptic to circular. The raphe is straight, with simple, straight proximal raphe ends. The terminal raphe fissures are simple and unilaterally deflected. Striae are not resolvable in LM. Large, distinctive, marginal pores are present numbering 10-13 in 10 µm.

In SEM, lineolae are evident on the valve face. The areolae are arranged in irregularly spaced striae, 34-40 in 10 µm. The striae are parallel at the middle part of the valve, becoming slightly radiate near the apices.


This taxon is typically found in low nutrient and low conductivity environments, particularly lakes and streams in alpine and subalpine regions.

It was first described by Krasske (1939) from subalpine ponds on a terrace of a volcano near Puyuhuapi, Chile.

The population illustrated here was found in sediments of Beauty Lake, Wyoming. At present time, the lake has low conductivity (111 μS/cm), low soluble reactive phosphorus (<0.02 μM) and low nitrate (<0.01–0.072 μM) (Saros et al. 2003). It was found in sediments during phases of increased Fe and P burial ~1700 and ~ 6200 years before present (YBP) (Spaulding et al. 2020).

It was also reported from sediments ~1900 YPB in Lac La Croix, Minnesota (Serieyssol et al. 2009). Currently, Lac La Croix has an alkalinity of 12 mg/L, pH of 6.5, low conductivity (42 μS/cm), and low total phosphorus (0.017 mg/L).

This taxon has been reported (as Pinnularia schwabei) from Boyanska River in Vitosha Nature Park, Bulgaria (Isheva and Ivanov 2016). The Boyanska River is at high elevation (1210 m), low temperature (4.5°C), neutral pH (7.3), and low conductivity (192 μS/cm). It has also been reported from the Sakhalin Islands, Russia (Medvedeva and Nikulina 2014).

Original Description

270. Pinnularia schwabei nov. spec. - Tafel XI, Fig. 19-21.
Schalen elliptisch bis linear mit ± leicht eingezogenen Seiten. Enden ± breit vorgezogen, gerundet. 19-22µ lang, 4-5µ breit. Längsarea breit, in der Mitte night erweitert. Streifen 10 in 10µ, parallel. Charakteristisch sind die Raphe zugewandten Kammeröffnungen, die bei P. ambigua Cl. ähnlich sind. - Haufig im Grundschlamm des Teiches auf der Dachstein-Westplatte.

Die Art is dem Sammler dieses Materials und ersten Bestieiger des Dachsteins, Herrn Dr. G. H. SCHWABE, gewidmet.

  • Basionym
    Pinnularia schwabei
  • Author
    Krasske 1939
  • Length Range
    19-22 µm
  • Width
    4-5 µm

Original Images

Krasske 1939 tafel XI fig 19 21
Krasske 1939 schwabei

Citations & Links



  • Index Nominum Algarum
  • DiatomBase
  • The Academy of Natural Sciences, Drexel University

Cite This Page

Mohan, J., Edlund, M., Stone, J. (2022). Pulchellophycus schwabei. In Diatoms of North America. Retrieved June 13, 2024, from https://diatoms.org/species/pulchellophycus-schwabei


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