Diatoms of North AmericaDiatoms of North America

Diadesmis confervacea

Kütz. 1844

Diadesmis Confervacea Guide
  • Category
    Symmetric Biraphid
  • Length Range
    14-18 µm
  • Width Range
    6.5-7.5 µm
  • Striae in 10 µm
    18-21
  • Synonyms
    Navicula confervacea (Kütz.) Grunow in Van Heurck 1880

Identification

Diadesmis confervacea LM3 Diadesmis confervacea LM4 Diadesmis confervacea LM5 Diadesmis confervacea LM2 Diadesmis confervacea LM1
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Description

Valves are elliptic, with apiculate apices. The central area is broad and rounded. The axial area tapers from the central area, becoming more narrow toward the ends. A rounded, thickened central nodule is visible when focusing on the interior of the valve. The raphe is straight and filiform, although the raphe may not be apparent. During the process of valve formation, the raphe may be secondarily filled with silica. As a result, the raphe of some valves may not be visible. The striae are radiate, punctate, and crossed by longitudinal wavy lines. Striae are variable in length.

Autecology

This species is typically found in waters living in chains of cells, aligned valve face to valve face. It has been documented across North America and is common in Lake Okochobee, Florida.

Diadesmis confervacea1
Credit: Hannah Innocent
Filament of living cells, Lake Okochobee, Florida
Diadesmis confervacea3
Credit: Hannah Innocent
Filament of living cells, Lake Okochobee, Florida
Diadesmis confervacea4
Credit: Hannah Innocent
Filament of living cells, Lake Okochobee, Florida
Diadesmis confervacea5
Credit: Hannah Innocent
Filament of living cells, Lake Okochobee, Florida

Original Description

DIADESMIS CONFERVACEA. Taf. 30. Fig. 8. (420/1). D. laevis articulata, articulis diametro duplo brevioribus, altero latere lanceolatis, utrinque acuminatis acutis. Long. (Navicularum) Unter Conferven aus dem „River Maraval" der Insel Trinidad: Krüger! (Herb, Sonder.)

  • Author
    Kütz. 1844

Original Images

Diadesmis confervacea orig illus
Diadesmis Confervacea Descr

Cite This Page

Kociolek, P. (2011). Diadesmis confervacea. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/diadesmis_confervacea

Responses

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