Navicula caroliniae | Species - Diatoms of North America

Category

Symmetric Biraphid
Length Range

23-41 µm
Width Range

7.9-9.9 µm
Striae in 10 µm

11-14

Contributor

Loren Bahls - Mar 2012
Reviewer

Mark Edlund - May 2012

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Identification

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Description

Valves are broadly lanceolate with rounded, rostrate apices. Raphe branches are weakly lateral. Proximal raphe ends are straight or deflected slightly to the secondary side. Distal raphe fissures are hooked to the secondary side. The axial area is narrow and linear, widening slightly toward the central area. The central area is large, rounded, and asymmetric, always smaller on the secondary side of the valve. Striae are evenly spaced throughout, radiate in the center and becoming parallel to slightly convergent at the apices. Areolae number 24–28 in 10 μm and are visible in LM.

Autecology

Navicula caroliniae has been collected from 17 lakes, ponds, and slow-moving streams in the Canadian Rockies (“Crown of the Continent”) Ecoregion of Montana and Alberta, where it is present in low numbers. It prefers waters with circumneutral to somewhat alkaline pH (range 6.5-8.6) and low to moderate levels of electrolytes (range 92-332 μS/cm).

Size Range, µm3

1001-10000
Motility

Moderately motile
Attachment

Unattached
Habitat

Benthic
Colony

Solitary
Waterbody

Inland
Learn more about this

Credit: Loren Bahls

Bowman Lake, Glacier National Park, Montana: type locality of Navicula caroliniae.

Original Description

Valves broadly lanceolate with protracted, obtusely rounded to subcapitate ends, 23–40 μm long, 7.9–9.9 μm wide. Raphe weakly lateral, proximal raphe endings straight or deflected slightly to the secondary side, distal fissures hooked to the secondary side. Axial area narrow, linear, widening slightly toward the central area. Central area large, rounded, and asymmetric. Striae radiate, becoming parallel to slightly convergent at the ends, 11–14 in 10 μm, lineolae 24 – 28 in 10 μm, visible in LM. For measurements, n = 30 valves. SEM (Figs 42 – 44): External raphe fissures weakly lateral, proximal endings defl ected slightly to the secondary side. Distal raphe endings hooked, the hooks opening toward the secondary side (the side with the Voigt faults). Other external features unremarkable for Navicula species.

Author

Bahls 2012
Length Range

23-40 µm
Width

7.9-9.9 µm
Striae in 10µm

11-14

Original Images

Citations & Links

Citations

Bahls, L.L. (2012) Seven new species in Navicula sensu stricto from the Northern Great Plains and Northern Rocky Mountains Nova Hedwigia, Beiheft 141: 19–38

Cite This Page

Bahls, L. (2012). Navicula caroliniae. In Diatoms of North America. Retrieved December 21, 2024, from https://diatoms.org/species/48341/navicula_caroliniae

Responses

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