• Category
  • Length Range
    134-174 µm
  • Width Range
    24-27 µm
  • Striae in 10 µm
    5

Identification

Description

Valves are linear with parallel margins and broad, rounded ends. The central area is small and asymmetric, expanded on the primary valve side of the valve. The axial area is linear, tapering at the ends, and less than 1/3 the breadth of the valve. This central nodule is visible by a darkening in the central area, where the silica cell wall is comparatively thick. The raphe is complex and the outer fissure is strongly undulate. The distal raphe ends are shaped like a question mark. Striae are mostly parallel, or slightly radiate in the center. Striae are crossed by a distinct longitudinal band, about one third of the length of the striae.

The species has been reported measuring up to 280 µm in length in European waters (Krammer 2000). A number of varieties of P. streptoraphe have been described (Krammer 2000).

Autecology

Pinnularia streptoraphe was found in an epipelic sample from Reiher Fen in Butler County, Iowa. Reiher Fen is a soft-water fen fed by subsurface water within a Pleistocene glacial sand ridge. In specimens from the Reimer Herbarium, P. streptoraphe was verified in the sphagnum bog of Dead Man’s Lake in Pilot Knob State Park, Iowa.

This taxon has been reported from numerous from lakes, ponds, bogs and marshes. In the original description, Cleve (1891) reports this taxon from New York, Massachusetts, and Nova Scotia.

It appears to prefer northern temperate climates and oligo- to dystrophic waters with low mineral content and low pH.

Livepinnularia1
Credit: Sample collection by Steve Main. Photo by Gosia Mahoney.
Pinnularia streptoraphe - live specimen in an epipelic sample from Reiher Fen, Iowa.
Livepinnularia2
Credit: Sample collection by Steve Main. Photo by Gosia Mahoney.
Pinnularia streptoraphe - live specimen in an epipelic sample from Reiher Fen, Iowa.

Original Description

P. streptoraphe CI. n. sp. — Valve linear, with rounded, broad ends, and parallel margins, 0,13 5 to 0,2 m. m. in length and 0,0 2 to 0,0 3 m. m. in breadth. Striae almost parallel or slightly radiant, 5 in 0,oi m. m., crossed by a very distinct band, about one third of the length of the striae. Area narrow. Raphe strongly twisted. This species is always easely recognized, and is well figured by A. Schmidt (Atl. XLII, 7) and Grunow (Nav. viridis var. sublinearis F. Jos. Land 1,22). — As the name sublinearis already has been given to a Pinnularia (V. H. VI, 25, 26), I think it may be most conveniant to propose a new name, which marks one of the most striking characteristics of the species. Pinn. streptoraphe is widely distributed. Swedish localities are Mudcles ape and Gellivaara in Lulea Lapmark, Idvattnet in Wilhelmina Lapmark, Sorcelet in Jamtland, Vernamo and Forarn (Asnen) in Smaland (all fossil). It occurs also in British deposits from Island of Lewis and in Premney Peat, on Franz Josephs Land (Grun.), in Lac de Grandlieu (Loire inferieur). American localities are: Sing-sing (N. Y.), Salem (Mass.), French pond (Albany), Nova Scotia, Sta Rosa (Gal.). Ab. 36, Lim. 21, Lt. 29, 31.

  • Author
    Cleve 1891
  • Length Range
    135-200 µm
  • Width
    20-30 µm
  • Striae in 10µm
    5

Original Images

Pinnularia Streptoraphe Cleve Orig Desc

Cite This Page

Mahoney, G. (2018). Pinnularia streptoraphe. In Diatoms of North America. Retrieved August 25, 2019, from https://diatoms.org/species/pinnularia-streptoraphe

Responses

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