• Category
  • Length Range
    18-50 µm
  • Width Range
    7.0-10.2 µm
  • Striae in 10 µm



Valves are linear-lanceolate to elliptic-lanceolate with subtly protracted and broadly rounded apices. Long but narrow lyrate lateral sterna occupy the center of the valve. The axial area is very narrow and barely wider than the raphe. The central area connecting lateral sterna is transverse and rectangular. Partecta near the middle of the valve are considerably larger than those closer to the apices. The raphe is weakly lateral with slightly enlarged proximal ends that extend a short distance into the central area. Raphe branches are straight (not sinuous) and bordered on each side by short sections of striae consisting of one or two adjacent areolae. Striae consist of single rows of areolae, are parallel in the middle of the valve, and become radiate towards the apices. Areolae are indistinct in LM and number 26-30 in 10 µm.


Mastogloia pumila has been reported from estuaries and bays along the Atlantic coast and the Gulf of Mexico (Patrick and Reimer 1966). Inland, this taxon was found in Salt Creek and Stockade Beaver Creek below Salt Creek in northeast Wyoming near Newcastle. Salt Creek is fed from salt springs and has a specific conductance of 45,700 µS/cm and a chloride concentration of 13200 mg/L. Specific conductance in Stockade Beaver Creek is 18100 µS/cm and chloride measures 5060 mg/L. In Europe, Krammer and Lange-Bertalot (1986) report Mastogloia pumila from sediments along sea coasts and from inland waters in coastal areas.

Sb Below  Salt  Us
Credit: State of Wyoming DEQ
Stockade Beaver Creek below Salt Creek, Weston County, Wyoming.

Original Description

M. braunii var. pumila Grun.! (Atl. Pl. 4 fig. 23). Petit, gréle, à espaces hyalins à double courbure; stries 23 à 24 en 1 c.d.m. Longueur environ 3 c.d.m. Non encore trouvé.

  • Basionym
    Mastogloia braunii var. pumila
  • Author
    Grunow in Van Heurck 1880
  • Length Range
    about 30 µm
  • Striae in 10µm

Original Images

Maspumila Origimag
Maspumila Origdesc

Cite This Page

Bahls, L. (2012). Mastogloia pumila. In Diatoms of North America. Retrieved June 21, 2024, from https://diatoms.org/species/mastogloia_pumila


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