Diatoms of North AmericaDiatoms of North America

Pinnularia cuneicephala

(A.Mann) R.M.Patrick 1966

Pinnularia Cuneicephala Guide
  • Category
    Symmetric Biraphid
  • Length Range
    79-142 µm
  • Width Range
    14-19 µm
  • Striae in 10 µm
    6-7

Identification

Pinnularia cuneicephala LM4 Pinnularia cuneicephala LM6 Pinnularia cuneicephala LM1 Pinnularia cuneicephala LM8 Pinnularia cuneicephala LM5 Pinnularia cuneicephala LM7 Pinnularia cuneicephala LM2
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Description

Valves are large and linear, with a gibbous center and cuneate ends. The axial area is large, taking up roughly 2/3 of the valve surface, and is distinctly mottled. The striae are short, evenly spaced throughout and parallel. The raphe is slightly lateral, and arcs to one side. The proximal raphe ends deflect gradually across the midline toward the opposite margin, and end in a teardrop shape. The distal raphe ends extend farther than in most Pinnularia species, so the "question mark-shaped" deflections are not easily visible in LM.

Autecology

Pinnularia cuneicephala is known from New England states and New Jersey. It is found in cool, freshwater lentic systems low in mineral content (Patrick and Reimer 1966).

Halls Pond
Credit: www.fishingnortheast.net
Hall's Pond, Connecticut, where Pinnularia cuneicephala has been documented.

Original Description

Navicula cuneicephala Mann, nom. nov.* Pl. 4, f. 5; see also Sch. At. pl. 43, f.19. My form agrees closely with the illustration in Schmidt's Atlas; but, as in the case of N. bihastata, I cannot use the specific name already given because of N. integra W.S.

  • Basionym
    Navicula cuneicephala
  • Author
    A.Mann 1924

Original Images

Navicula Cuneicephala Orig
Navicula cuneicephala orig descr

Cite This Page

Polaskey, M., Ripple, H. (2018). Pinnularia cuneicephala. In Diatoms of North America. Retrieved April 23, 2024, from https://diatoms.org/species/pinnularia_cuneicephala

Responses

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