• Category
  • Length Range
    16-35 µm
  • Width Range
    7-8 µm
  • Striae in 10 µm
    24-28

Identification

Description

Valves are linear-elliptic with rounded apices. The axial area is narrow and linear. The central area is broad and transversely elliptic to somewhat rectangular. Striae are radiate throughout, more strongly so near the central area. Striae are variable in length near the central area. Distal raphe ends are straight and undeflected.

Autecology

Cavinula variostriata has been reported from sites across the United States, from Alabama in the south to Alaska in the north. While it is widely distributed, it is considered to be rare in occurrence because it is typically low in aboundance.

0242354750Web
Credit: USGS.
USGS station 0242354750 - Cahaba Valley Creek near Pelham, Al., where C. variostriata can be found.
C  Variostriata Biodata Map
Credit: USGS Biodata.
C. variostriata distribution from USGS Biodata.

Original Description

N. variostriata nov. spec. - (Fig. 12). - Lang elliptisch mit breit gerundeten Enden, enger Axial- und weiter, runder Zentral-Area. Streifen strahlend und schwach gebogen, die mittleren abwechselnd länger und kürzer, auch etwas kräftiger als die anern, ungefähr 30 in 10µ. Länge 38µ, Breite 10µ. - Fundort: Christteich am Stellberg (Söhre). - Diese im Christteich nur wenigen Exemplaren gefundene Art traf ich häufig in einem Material an, das aus einem Moosrasen einer quelligen Stelle an einer Bergheide bei Vockerode (Spangenberg) sammte, der mir von Herrn Veterinärrat Dr. GRIMME-Cassel in dankenswerter Weise zur Verfügung gestellt war.

  • Basionym
    Navicula variostriata
  • Author
    Krasske 1923
  • Length Range
    38 µm
  • Width
    10 µm
  • Striae in 10µm
    30

Original Images

Cavinula variostriata orig illus
Navicula Variostriata Orig Desc

EMAP Assessment

EMAP Distribution

Cavinula Variostriata   Krasske   Lange  Bertalot 20
Map 40

Response Plots

Cavinula Variostriata   Krasske   Lange  Bertalot

Cite This Page

Tyree, M., Ripple, H. (2018). Cavinula variostriata. In Diatoms of North America. Retrieved September 23, 2019, from https://diatoms.org/species/cavinula_variostriata

Responses

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