Diatoms of North AmericaDiatoms of North America

Navicula cryptocephala

Kütz. 1844

Navicula Cryptocephala Guide
  • Category
    Symmetric Biraphid
  • Length Range
    21-34 µm
  • Width Range
    5.2-6.5 µm
  • Striae in 10 µm
    15-17

Identification

Navicula cryptocephala LM4 Navicula cryptocephala LM6 Navicula cryptocephala LM2 Navicula cryptocephala LM7 Navicula cryptocephala LM5 Navicula cryptocephala LM1 Navicula cryptocephala LM3
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Navicula cryptocephala SEM1 Navicula cryptocephala SEM3

Description

Valves are lanceolate with protracted apices The axial area is narrow and straight. The central area is large and circular. The raphe is straight, with 'drop-like' expanded external proximal ends. Striae are radiate around the center, becoming convergent at the apices. The areolae are sometimes visible under LM, and number approximately 35 in 10 μm.

Autecology

This taxon is broadly distributed in rivers and lakes of the US. It is common in waters of moderate to high pH, in higher nutrient waters, and in sites with higher sedimentation.

Original Description

N. minuta, laevissima, anguste lanceolata acuminate, apicibus globuloso-capitatis. Long. 1/75’’’-1/85’’’.

  • Author
    Kütz. 1844
  • Length Range
    26.5-30 µm

Original Images

Nacryptoc Or Ill1
Nacryptoc Or Ill2
Na Cryptoceph Or Descr

Cite This Page

Potapova, M. (2011). Navicula cryptocephala. In Diatoms of North America. Retrieved April 18, 2024, from https://diatoms.org/species/navicula_cryptocephala

Responses

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