Diatoms of North AmericaDiatoms of North America

Fragilaria mesolepta

Rabenh. 1861

Fragilaria Mesolepta Guide
  • Category
    Araphid
  • Length Range
    13-44 µm
  • Width Range
    2-3.5 µm
  • Striae in 10 µm
    13-17
  • Synonyms
    Fragilaria capucina var. mesolepta (Rabenh.) Rabenh. 1864
    Fragilaria virescens f. mesolepta (Rabenh. and Schönf.) A.Cleve 1953
    Staurosira capucina var. mesolepta (Rabenh.) Comère 1892

Identification

Fragilaria mesolepta LM2 Fragilaria mesolepta LM3 Fragilaria mesolepta LM3 Fragilaria mesolepta LM5 Fragilaria mesolepta LM6 Fragilaria mesolepta LM1 Fragilaria mesolepta LM7
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Description

Valves are linear-lanceolate and slightly panduriform. The valves are constricted at mid-valve and expanded toward the apices. Apices are rostrate to subcapitate. Striae are parallel and indistinct. The striae from opposite margins may be aligned, or may be slightly off set from one another. Some specimens possess faint striae in the central area. The axial area is narrow. Frustules are linked to form colonies.

The morphology presented here conforms to the type illustrations (Tuji and Williams 2008).

Autecology

Fragilaria mesolepta was found in the plankton of West Lake Okoboji and Beck’s Canal in Dickinson County, Iowa, in an algal squeezing from Union Slough, Kossuth County, Iowa, and in epilithic samples from the Missouri River (Yankton, South Dakota).

Fragilaria Mesolepta1
Credit: USGS BioData
Distribution of Fragilaria mesolepta in rivers of the continental U.S. based on the National Water Quality Assessment program. Retrieved 03 June 2015.
Fragilaria Mesolepta2
Credit: USGS BioData
Distribution of Fragilaria mesolepta in rivers of Alaska based on the National Water Quality Assessment program. Retrieved 03 June 2015.
Fragilaria Mesolepta3
Credit: USGS BioData
Distribution of Fragilaria mesolepta in rivers of Hawaii based on the National Water Quality Assessment program. Retrieved 03 June 2015.

Original Description

  • Author
    Rabenh. 1861

Original Images

Fragilaria mesolepta orig illus
Fragilaria mesolepta orig illus

Cite This Page

Balmaki, B. (2015). Fragilaria mesolepta. In Diatoms of North America. Retrieved April 18, 2024, from https://diatoms.org/species/fragilaria_mesolepta

Responses

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