Navicula aitchelbee
Bahls 2012 Category: Symmetrical biraphid
BASIONYM: Navicula aitchelbee Bahls 2012
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Loren Bahls - March 2012
Length Range: 20-36 µm
Width Range: 4.8-7.0 µm
Striae in 10 µm: 14-16
Description
Valves are narrowly lanceolate with subcapitate apices. Raphe branches are filiform with proximal endings deflected to the primary side. Distal raphe fissures are hooked to the secondary side. The axial area is very narrow and widens somewhat near the small, asymmetric central area. Striae are radiate and become convergent at the ends. Areolae number approximately 32 in 10 μm and are usually visible in LM.
Original Description
Basionym: Navicula aitchelbee
Author: Bahls 2012
Length Range: 20-36 µm
Width Range: 4.8-7.0 µm
Striae in 10 µm: 14-16
Original Description
Valves narrowly lanceolate with subcapitate ends, 20–36 μm long, 4.8–7.0 μm wide. Raphe filiform, proximal endings deflected to the primary side, distal raphe fissures hooked, opening to the secondary side. Axial area very narrow, widening somewhat near the small, asymmetric central area. Striae radiate, convergent at the ends, 14 –16 in 10 μm, lineolae about 32 in 10 μm, visible in LM. For measurements, n = 40 valves. SEM (Figs 23 – 25): External raphe fissures filiform, proximal endings deflected slightly to the primary side. Distal raphe endings hooked, the hooks opening toward the secondary side (the side with the Voigt faults).
Original Images
Cite This Page:
Bahls, L. (2012). Navicula aitchelbee. In Diatoms of the United States. Retrieved May 18, 2013, from http://westerndiatoms.colorado.edu/taxa/species/navicula_aitchelbee
Species: Navicula aitchelbee
Contributor: Loren Bahls
Reviewer: Mark Edlund
Image Credit: Loren Bahls
- Apices subcapitate
- Central area small, asymmetric
- Striae straight, 14-16 in 10 μm
Navicula aitchelbee has lanceolate valves 20-36 μm long with subcapitate apices. The central area is small and asymmetric. Striae number 14-16 in 10 μm and are straight near the central area.
Compare
Navicula cincta var. rostrata has rostrate apices. Navicula cryptocephala has a rounded central area and striae that are curved about the central area. Navicula cryptofallax has narrower apices and a lanceolate central area. Navicula veneta has wedge-shaped apices and a transverse central area. Navicula caterva is smaller and has finer striae and a smaller central area.
Navicula cryptocephala
Navicula cryptofallax
Navicula caterva
Navicula veneta
Navicula cincta var. rostrata
Reimer 1961
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.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID:
Autecology Discussion
Navicula aitchelbee is widely distributed in soft-bottomed streams of the Northwestern Great Plains (eastern Montana and Wyoming, western North Dakota and South Dakota) where it may be locally abundant. In these streams the mean pH is 8.5 and the mean specific conductance is 3627 µS/cm. The most frequently co-occurring diatom associates of N. aitchelbee are also salt-loving, epipelic taxa: Nitzschia frustulum var. subsalina, Cylindrotheca gracilis, Entomoneis paludosa, Nitzschia nana, Synedra famelica, Navicula salinicola, Hippodonta hungarica, Ctenophora pulchella, Navicymbula pusilla, and Navicula eidrigiana.
Images
Abundance-weighted mean values for selected water quality variables measured concurrently with the collection of samples containing Navicula aitchelbee.
Credit/Source: Montana Diatom Database