Diatoms of North AmericaDiatoms of North America

Navicula caterva

M.H.Hohn and Hellerman 1963

Navicula Caterva Guide
  • Category
    Symmetric Biraphid
  • Length Range
    14.8-20.0 µm
  • Width Range
    4.4-5.0 µm
  • Striae in 10 µm
    18-20

Identification

Navicula caterva LM2 Navicula caterva LM1 Navicula caterva LM5 Navicula caterva LM8 Navicula caterva LM1 Navicula caterva LM3 Navicula caterva LM7
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Description

Valves are lanceolate with subrostrate ends. Striae are radiate at the valve center, becoming parallel to slightly divergent at the ends. Central striae may be bent with shortened striae enclosed by longer neighboring striae. The central area is small and transapically oval to rectangular in shape, occupying about 1/3 of the valve breadth.

Autecology

Original Description

Valva lanceolata, apicibus subrostratis leniter. Longitudo 10.4-16.6 µ. Latitudo 4.2-5.2 µ. Striis latis, punctatis obscure, radiates ad mediampartem, paralelis ad apices 16-18/10 µ. Area axiali lineari. Raphe tenui, directa. Area media parva, rectangulari transapicaliter.

Valve lanceolate, ends slightly subrostrate; length 10.4-16.6 µ, width 4.2-5.2 µ striae broad, indistinctly punctuate, radiate at center, parallel at ends 16-18/10 µ; axial area linear; raphe thin, straight; central area small, transapically rectangular.

Occasionally the center pair of striae are more shortened than illustrated and are enclosed by the adjacent striae.

This species is similar in size and shape to Navicula perparva Hust. (Arch. Hydrobiol. Suppl., 15: 246, pl. 20, figs 16-18, 1937) but differs in that the striae, particularly those at the ends, are coarse and parallel. In N. perparva the striae become quite fine at the ends and are radiate.

Specimen illustrated: GC. 44466, Type. Type locality: Potomac River, Md. Distribution: Type locality and Ridley Creek, Pa.

  • Author
    M.H.Hohn and Hellerman 1963
  • Length Range
    10.4-16.6 µm
  • Width
    4.2-5.2 µm
  • Striae in 10µm
    16-18

Original Images

H And H Navicula Caterva Drawing
H And H Navicula Caterva Description

Cite This Page

Edlund, M., Potapova, M., Spaulding, S. (2010). Navicula caterva. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/navicula_caterva

Responses

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