Achnanthidium duthiei
(Sreenivasa) Edlund 1994 Category: Monoraphid
SYNONYM(S): Achnanthes duthiei Sreenivasa
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Marina Potapova - August 2010
Length Range: 22-32 µm
Width Range: 4.5-5.2 µm
Striae in 10 µm: 14-22 in the center valve, 28-34 at the ends
Description
Valves are linear to linear-lanceolate, with broadly capitate ends. The raphe valve is concave and the rapheless valve is convex. Both valves possess a linear axial area, which widens slightly in the middle portion of the valve. No central area is present. The striae are parallel or very slightly radiate throughout both valves. Striae density on both valves is 14-22 in 10 µm in the middle and 28-34 in 10 µm at the apices. The external openings of the areolae are transapically elongated, appearing as narrow slits. Each stria in the middle part of the valve is composed of 4-5 areolae. The raphe is straight, filiform. The terminal raphe fissures are hooked towards the same side of the valve. Externally, the central raphe ends are teardrop-shaped. Internally, the central raphe ends curve to opposite sides.
Cite This Page:
Potapova, M. (2010). Achnanthidium duthiei. In Diatoms of the United States. Retrieved May 18, 2013, from http://westerndiatoms.colorado.edu/taxa/species/achnanthidium_duthii
Species: Achnanthidium duthiei
Contributor: Marina Potapova
Image Credit: Marina Potapova
- Valves linear to linear-lanceolate
- Valve ends broadly capitate
- Striae parallel or slightly radiate throughout both valves
Valves linear to linear-lanceolate with broadly capitate ends.The striae are parallel or very slightly radiate throughout both valves. Striae density on both valves is 14-22 in 10 µm in the middle and 28-34 in 10 µm at the apices.
Compare
Achnanthidium duthiei differs from A. latecephalum and Achnanthes lineariformis by valve shape. While A. duthiei valves are linear to linear-lanceolate with capitate apices, A. latecephalum has linear-lanceolate valves with broadly rostrate or subcapitate ends, is smaller in size, and has a higher striae density. Achnanthes lineariformis has linear to linear-elliptical valves.
Achnanthidium latecephalum
Achnanthes lineariformis
Lange-Bertalot
Citations
Edlund, M.B. (1994). Additions and confirmations to the algal flora of Itasca State Park. II. Diatoms from Chambers Creek. Journal of the Minnesota Academy of Science 59(1):10-21.
Ponader, K. and Potapova, M. (2007). Diatoms from the genus Achnanthidium in flowing waters of the Appalachian Mountains (North America): Ecology, distribution and taxonomic notes. Limnologica - Ecology and Management of Inland Waters 37: 227-241 . 10.1016/j.limno.2007.01.004
Sreenivasa, M.R. (1971). New fossil diatoms from Ontario. II. Achnanthes duthii sp. nov., Achnanthes undulatus sp. nov., and Neidium distincte-punctatum Hustedt var. major var. nov. Phycologia 10(1):79-82.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 1056