• Category
  • Length Range
    10.4-45.8 µm
  • Width Range
    5.2-7.0 µm
  • Striae in 10 µm
    18-23
  • Synonyms
    Diatoma anceps (Ehrenb.) Kirchn. 1878

Identification

Description

Valves apically and transapically symmetrical; linear with capitate ends. Small valves may be more elliptical with less capitate ends than larger valves. Valves possess both primary and secondary costae, which measure 3.3-4.9 in 10 µm. Striae are visible in LM but individual areolae cannot be observed. The sternum is central and well-defined. Each valve has a single, sub-apical rimoportula.

Autecology

Meridion anceps is widely distributed across North America, notably in the western United States. It can be found in aerophilic zones, wet walls, small creeks, larger rivers. It is common in submerged mosses and liverworts and co-occurs with several species in the Meridion, Diatoma, Tabellaria, and Tetracylus genera.

Screen  Shot 2015 05 08 At 4 13 38  Pm
Credit: USGS BioData
Distribution of D anceps in the continental U.S. rivers sampled for the National Water Quality Assessment program. (Retrieved 08 May 2015)
Screen  Shot 2015 05 08 At 4 14 18  Pm
Credit: USGS BioData
Distribution of D anceps in the Alaskan rivers sampled for the National Water Quality Assessment program. (Retrieved 08 May 2015)

Original Description

F? anceps, parva linearis testulis a latere laxe striatis, apicibus, constrictis obtusis subcapitatis. Gomphonema Pupulae affinis.

  • Basionym
    Fragilaria anceps
  • Author
    Ehrenb. 1843

Original Images

Original Description

EMAP Assessment

EMAP Distribution

Diatoma Anceps   Ehrenberg   Kirchner 3
Map 3

Response Plots

Diatoma Anceps   Ehrenberg   Kirchner

Cite This Page

Bishop, I. (2015). Meridion anceps. In Diatoms of North America. Retrieved July 23, 2018, from https://diatoms.org/species/meridion_ancep

Responses

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