Orthoseira roeseana
(Rabenhorst) Pfitzer 1871 Category: Centric
BASIONYM: Melosira roeseana Rabenhorst 1853
LM scalebar = 10 µm = 40 pixels.
Observations
Contributor: Mark Edlund | David R.L. Burge - July 2017
Diameter: 22.1-50.5 µm
Rows of areolae in 10 µm: 6.4-7.1 based on circumferential density
Description
Frustules are heavily silicified and aligned in short filaments of 2-10 cells adjoined face-to-face by short conical or flattened spines. The spines are regularly spaced along the face-mantle junction. Frustules are 39.7-51.1 µm long in the pervalvar axis. The base of the spines extend onto the mantle and may continue for a short distance onto the valve face. The mantle is broad. In smaller cells, the mantle height is relatively larger. Valves have a flat to slightly convex face. Valves have a small central area with 2-5 carinoportulae, a type of pore specific to the genus Orthoseira. Valve face areolae are arranged in radial striae that end in small furrows formed by adjacent spine bases near the face-mantle junction. Valve face areola density is 14.5-19.3 in 10 µm. The valve mantle has straight pervalvar striae (16.4-19.3 in 10 µm) with areola density 13.5-17.5 in 10 µm. Frustules with a broad cingulum. Girdle bands are variably ornamented with pervalvar rows of fine areolae.
The genus Orthoseira is recognized as needing monographic treatment to resolve the typification, taxonomy, and nomenclature of its common forms—roeseana, dendroteres, dendrophila, tatrica, circularis, americana, epidendron (Houk 1993, 2003, Spaulding and Kociolek 1998), which is complicated by the great morphologic variation within current taxa. Here, we follow the broad concept taxonomy for O. roeseana of Houk (2003).
Original Description
Basionym: Melosira roeseana
Author: Rabenhorst 1853
Diameter: 20 µm
Rows of areolae in 10 µm:
Original Description
Original Images
Cite This Page:
Edlund, M., and Burge, D. (2017). Orthoseira roeseana. In Diatoms of the United States. Retrieved August 21, 2017, from http://westerndiatoms.colorado.edu/taxa/species/orthoseira_roeseana
Species: Orthoseira roeseana
Contributor: Mark Edlund | David R.L. Burge
Reviewer: Sarah Spaulding
- Cells heavily silicified
- Marginal spines conical or flattened
- Carinoportulae 2-5
- Cells joined in filaments
Cells are heavily silicified, large and possess deep mantles. They are adjoined face-to-face by regularly spaced marginal spines. On the valve face, a small central area contains 2-5 carinoportulae.
Compare
Melosira dendrophila has spines grouped in marginal clusters, separated by porefields. Orthoseira johansenii has a larger central area with fine, weakly organized striae and spines separated by 2-4 striae.
Melosira dendrophila
(Ehrenberg) Ross & Sims
Orthoseira johansenii
Lowe & Kociolek
Citations
Foged, N. (1981). Diatoms in Alaska. Bibliotheca Phycologica, Band 53, J. Cramer, Vaduz, 317 pp.
Houk, V. (1993). Some morphotypes in the Orthoseira roeseana complex. Diatom Research 8: 385-402.
Houk, V. (2003). Atlas of Freshwater Centric Diatoms with a Brief Key and Descriptions. Part I. Melosiraceae, Orthoseiraceae, Paraliaceae and Aulacoseiraceae. Czech Phycology Supplement, Volume 1, Czech Phycological Society, Olomouc.
Pfitzer, E. (1871). Untersuchungen über Bau und Entwicklung der Bacillariaceen (Diatomaceen). Botanische Abhandlungen aus dem Gebiet der Morphologie und Physiologie. Herausg. von J. Hanstein, Bonn. 1(2): 189 pp.
Rabenhorst, L. (1853). Die Süßwasser-Diatomaceen (Bacillarien) für Freunde der Mikroskopie. Leipzig, 72 pp.
Roemer, S.C. and Rosowski, J.R. (1980). Valve and band morphology of some freshwater diatoms. III. Pre- and post-auxospore frustules and the initial cell of Melosira roeseana. Journal of Phycology 16(3): 399-411.
Sheath, R.G. and Steinman, A.D. (1982). A checklist of freshwater algae of the Northwest Territories, Canada. Canadian Journal of Botany 60: 1964-1997.
Spaulding, S.A. and Kociolek, J.P. (1998). The diatom genus Orthoseira: ultrastructure and morphological variation in two species from Madagascar with comments on nomenclature in the genus. Diatom Research 13: 133-147.
Stoermer, E. F., Kreis Jr, R. G., and Andresen, N. A. (1999). Checklist of diatoms from the Laurentian Great Lakes. II. Journal of Great Lakes Research 25 (3), 515-566.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 74001
Autecology Discussion
Orthoseira roeseana is an aerophilic species found on wet walls and moist subaerial habitats. It is found across a broad latitudinal gradient, from small ponds in Alaska (Foged 1981) to subaerial habitats in Ohio (this material and Roemer and Rosowski 1980), the Great Lakes (Stoermer et al. 1999), the Northwest Territories (Sheath and Steinman 1982) and subtropical regions (Spaulding and Kociolek 1998).
Images
Girdle view of filament, at two levels of focus (Science Museum of Minnesota MBE 825A).
Credit/Source: M. Edlund
Girdle view of filament, showing the silica spines that join frustules together (Science Museum of Minnesota MBE 825A).
Credit/Source: M. Edlund
Low magnification image of a large number of Orthoseira roeseana filaments (Academy of Natural Sciences of Drexel University GC3441).
Credit/Source: S. Spaulding