• Category
  • Length Range
    23.8-44.8 µm
  • Width Range
    7.9-10.4 µm
  • Striae in 10 µm



Valves are linear to elliptic, with rostrate to subrostrate apices. The axial area is narrow. The central area is relatively large and circular to quadrilateral and transapically elongated. The raphe is straight. The proximal raphe ends are slightly enlarged. The distal raphe ends are difficult to resolve in LM. Partecta number 5-8 and are all of the same size. Striae are uniseriate and weakly radiate, becoming nearly parallel near the apices. Areolae are coarse and number 20 in 10 µm.


This taxon was described from Connelly Fen in Blackfeet Indian Reservation, Glacier County, Montana. At this site, the pH was 7.42 and specific conductance was 1600 µS/cm (Bahls 2017).

The images for this page are from periphyton sampled from a flark (calcium carbonate rich pool) near Silver Lake, Dickinson County, Iowa. The water from this site had a pH of 6.90, conductance of 3400 µS/cm, and temperature of 13.1 °C.

Credit: Oliver McLellan
Silver Lake flark sampling site, May 2022.

Original Description

Mastogloia taralunae sp. nov. Figures 222-234

Valves are linear with rostrate apices in the largest specimens, elliptic with cuneate apices in smaller specimens. Valve length 27-49 µm; valve width 9.0-12.2 µm. The axial area is very narrow. The central area is large and circular or transversely rectangular. The raphe is filiform and straight. Proximal raphe ends are also straight and slightly inflated. Distal raphe fissures are indistinct. Partecta are all of the same size and number 7 in 10 µm. Striae are weakly radiate, 14 in 10 µm. Areolae number about 20 in 10 µm. [n=30]

Holotype: USA, Montana: Blackfeet Indian Reservation, Glacier County, Connelly Fen, 48.6208°N, -112.7775°W, coll. Peter Lesica, 9 September 2013, MDC sample 514201, MDC slide 45-45 (holotype is Fig. 233) MONTU! MDC slide 130-39.

Ecology & Distribution: Specific conductance at the type locality was 1600 µS/cm and pH was 7.42.

Etymology: This species is named after Tara Luna, a Montana botanist who lives and works on the Blackfeet Reservation where the type material was collected.

  • Author
    L.L. Bahls 2017
  • Length Range
    27-49 µm
  • Width
    9.0-12.2 µm
  • Striae in 10µm

Original Images

Mastogloia taralunae orig illus
Mastogloia taralunae orig desc

Cite This Page

McLellan, O. (2024). Mastogloia taralunae. In Diatoms of North America. Retrieved April 14, 2024, from https://diatoms.org/species/mastogloia-taralunae


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