• Category
  • Length Range
    18-32 µm
  • Width Range
    6.8–7.8 µm
  • Striae in 10 µm
    22–23

Identification

Description

Valves are elliptic, with broadly rounded ends that are only very slightly protracted. The axial area is narrow and straight. The central area is bow-tie-shaped and relatively small. The center area is bounded by alternating short and long striae. The striae are radiate throughout most of the valve, becoming parallel or slightly convergent at the ends. The areolae are small, round and number approximately 50 in 10 μm. At the valve ends, the striae are interrupted and internally form “polar bars,” a feature visible in LM. The raphe is straight, with proximal ends externally slightly bent toward the primary side of the valve. The external surface of the valve face is smooth, without visible grooves or conopea.

Autecology

Original Description

Valves are 6.8–7.8 μm wide, 18–32 μm long, elliptical, with broadly rounded and only very slightly protracted ends (Fig. 2). The axial area is narrow and straight. The central area is bow-tie-shaped, with alternating short and long striae, relatively small. The uniseriate striae are radiate throughout most of the valve, and parallel or slightly convergent at the ends; striae density is 22–23 in 10 μm. The areolae are small, rounded, approximately 50 in 10 μm transapically. At the valve ends the striae are interrupted and internally form “polar bars,” which are visible on LM photographs (Figs 2A-I). The raphe is straight, with central endings externally slightly bent towards the primary side of the valve (Figs 2K, L), and terminal fissures curved towards secondary side of the valve (Figs 2J, L). The external surface of the valve face is smooth without visible grooves or conopea often present in Sellaphora.

  • Author
    Potapova and Ponader 2008
  • Length Range
    18–32 µm
  • Width
    6.8–7.8 µm
  • Striae in 10µm
    22–23

Original Images

Sellaphora Meridionalis  Orig Ill
Sellaphora Meridionalis  Orig Descr

Cite This Page

Potapova, M. (2013). Sellaphora meridionalis . In Diatoms of North America. Retrieved August 15, 2018, from https://diatoms.org/species/sellaphora_meridionalis

Responses

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