Achnanthes mauiensis
Lowe & Sherwood 2009 Category: Monoraphid
BASIONYM: Achnanthes mauiensis Lowe & Sherwood 2009
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Rex Lowe - December 2011
Length Range: 22.4-27.1 µm
Width Range: 5-7.5 µm
Striae in 10 µm: 15-19 on both valves
Description
Valves are linear with a gibbous center and narrow, rostrate ends. Some specimens are not symmetric to the apical axis, and have ends that are slightly bent. The raphe valve has a narrow axial area and the central area is expanded to the valve margins. The proximal raphe ends are slightly deflected in one direction. The distal ends are curved strongly towards the mantle, in the opposite direction of the proximal deflection. The axial area of the rapheless valve is positioned near the valve margin. The striae are punctate and radiate on raphe valve. The striae on the rapheless valve are parallel in the center, becoming radiate with respect to the axial area and slightly curved at the apices.
Original Description
Basionym: Achnanthes mauiensis
Author: Lowe & Sherwood 2009
Length Range: 20-28 µm
Width Range: 5.0-7.5 µm
Striae in 10 µm: 15-19
Original Description
Valves linear, swollen in the center, with narrowed rostrate ends, 20-28 µm long, 5.0-7.5 µm wide. Raphe valve with narrow axial area, with central area expanded to the valve margins (Figs 9-12, 17, 18). Raphe with proximal ends deflected slightly in one direction, with distal ends curved strongly towards mantle in opposite direction (Fig. 17). Rapheless valve with axial area near valve margin (Figs 13-16, 19), Striae punctate, radiate on raphe valve, on rapheless valve parallel in the center, becoming radiate with respect to the axial area and slightly curved at the apices, 15-19 in 10 gm on both valves. Puncta 20 in 10 µm on both valves.
Original Images
Cite This Page:
Lowe, R. (2011). Achnanthes mauiensis. In Diatoms of the United States. Retrieved May 25, 2013, from http://westerndiatoms.colorado.edu/taxa/species/achnanthes_mauiensis
Species: Achnanthes mauiensis
Contributor: Rex Lowe
Reviewer: Sam Rushforth
Image Credit: Rex Lowe
- Valves linear
- Center valve gibbous
- Raphe valve with broad central area
- Rapheless valve with eccentric axial area
Valves are linear, with a gibbous center. The ends are narrow, rostrate ends and may be asymmetric to the apical axis. The raphe valve has a narrow axial area, with a central area expanded to the valve margins. The rapheless valve with the axial area positioned near valve margin. Striae are punctate.
Compare
The striae of Achnanthes coarctata are more coarse and the valves are more robust than A. mauiensis.
Achnanthes coarctata
Citations
Lowe, R.L., Sherwood, A.R. and Ress, J.R. (2009). Freshwater species of Achnanthes Bory from Hawai'i. Diatom Research 24(2): 327-340.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID:
Autecology Discussion
Present only on two collections from Maui from a wet wall along the Hana Highway. It occurred in association with Diadesmis pantropica, Diadesmis sp., Achnanthes inflata, Geissleria ignota, Fallacia insociabilis and Nitzschia cf. clausii.