• Category
  • Length Range
    13.1-16.6 µm
  • Width Range
    4.6-5.8 µm
  • Striae in 10 µm
    18-24

Identification

Description

Valves are lanceolate-elliptical with protracted, capitate apices. The axial area is narrow and straight. The raphe is filiform. The central area is transversely oriented and irregularly shaped. Striae are parallel throughout, with an increasing density toward the valve ends. The striae are irregularly interrupted. Areolae are coarse and and visible in LM.

Autecology

Screen  Shot 2015 05 08 At 4 24 47  Pm
Credit: USGS BioData
Distribution of C. citrus in continental U.S. rivers as reported in the National Water Quality Assessment program. Retrieved 08 May 2015.

Original Description

Protolog: N. Citrus nov.spec. - (Fig. 14). - Elliptisch, dünnschnabelige Enden, schmale Längs- und verbreiterte Zentralarea, Streifen grob punktiert, strahlend, die beiden mittelsten abgekürzt, die folgenden gebogen, konvexe Seite den Enden zugewandt. 15 in 10 um, Länge 22, Breite 8 um. - Fundort: Graben zqischen Fuldadamm und Karlsaue (Cassel). - Systematische Stellung noch fraglich.

Holotypus: A I 92 (Hessen), nur ein Exemplar, markiert.
Weitere Belege: Nur noch aus Formosa, E III 18 und Chile, D III 819.

Bemerkungen: Navicula citrus ist eine gut kennliche, bis jetzt jedoch noch relativ selten gefundene Art. HUSTEDT (1961 - 1966, p. 780) berichtet von einem Fund außerhalb Europas auf der Insel Luzon/Philippinen. Inzwischen sind weitere Funde in der Literatur gemeldet worden, z. B. erwähnt REICHARDT (1984, p. 42) mehrere Vokommen in der Altmuhl (Süddeutschland) bei Treuchtlingen.

  • Basionym
    Navicula citrus
  • Author
    Krasske 1923
  • Length Range
    22 µm
  • Width
    8 µm
  • Striae in 10µm
    15

Original Images

 Navicula citrus orig illus
Navicula citrus orig illus

EMAP Assessment

EMAP Distribution

Craticula Citrus   Krasske   Reichardt 10
Map 10

Response Plots

Craticula Citrus   Krasske   Reichardt

Cite This Page

Burge, D, and Bishop, I. (2015). Craticula citrus. In Diatoms of North America. Retrieved December 16, 2018, from https://diatoms.org/species/craticula_citrus1

Responses

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