Cosmioneis citriformis
Sherwood and Lowe in Lowe and Sherwood 2010 Category: Symmetrical biraphid
BASIONYM: Cosmioneis citriformis Sherwood and Lowe in Lowe and Sherwood 2010
REPORTED AS: Cosmioneis pusilla (Witkowski et al. 2000 Pl. 107, figs 1,2,12,13) | Cosmioneis pusilla (Krammer and Lange-Bertalot 1997 Pl. 57, fig. 8)
LM scalebar = 10 µm = 40 pixels.
Observations
Contributor: Rex Lowe - December 2011
Length Range: 29.4-33.2 µm
Width Range: 12.5-15.7 µm
Striae in 10 µm: 17 in the center, 20 near the ends
Description
Valves are citriform, with broadly rounded margins. The ends are short, narrow and rostrate. The axial area is narrow, expanding to rounded central area. The proximal raphe ends are slightly expanded. The distal raphe ends are curved in the same direction. Internally, the raphe ends are anchor-shaped. Striae are punctate and radiate, curving from the margin toward the center of the valve. Striae are 17 in 10 μm in the center, becoming finer at the ends (20 in 10 µm). Areolae number 16 in 10 µm and are round toward the valve ends, becoming transversely elongated near the center.
Original Description
Basionym: Cosmioneis citriformis
Author: Sherwood and Lowe in Lowe and Sherwood 2010
Length Range: 26.5-34 µm
Width Range: 12.2-15.7 µm
Striae in 10 µm: 17 in center, 20 near the ends
Original Description
Valves are citriform with broadly rounded margins curving to short narrow rostrate ends. Valves are 26.5-34 μm long and 12.2-15.7 μm wide. The axial area is narrow expanding to rounded central area. The proximal raphe ends are slightly expanded on the valve surface in pyriform depressions. The distal raphe ends are curved in the same direction. Internally, raphe ends are anchor-shaped. Striae are punctate, and radiate, curving from the margin toward the center of the valve. Striae are 17 in 10 μm in the center becoming finer at the ends (20/10µm). Puncta number 16/10µm and are round toward valve ends becoming transversely elongated near center.
Original Images
Cite This Page:
Lowe, R. (2011). Cosmioneis citriformis. In Diatoms of the United States. Retrieved May 23, 2013, from http://westerndiatoms.colorado.edu/taxa/species/cosmioneis_citriformis
Species: Cosmioneis citriformis
Contributor: Rex Lowe
Image Credit: Rex Lowe
- Valve margins broadly rounded
- Ends short, rostrate
Valves are citriform with broadly rounded margins curving to short narrow rostrate ends. The central area is rounded and the proximal raphe ends are slightly expanded externally. Striae are punctate, radiate and curve toward the center of the valve.
Compare
Cosmioneis pusilla is larger and more lanceolate than C. citriformis.
Cosmioneis pusilla
(Smith) Mann et Stickle
Citations
Lowe, R.L. and Sherwood, A.R. (2010). Three new species of Cosmioneis (Bacillariophyceae) from Hawai'i. Proceedings of the Academy of Natural Sciences of Philadelphia 160(1):21-28. 10.1635/053.160.0104
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID:
Autecology Discussion
Populations of C. citriformis from Hawai’i are found in fresh water, primarily waterfall spray zones and wet walls.