(Brébisson ex W. Smith) Grunow in Cleve and Grunow 1880 Category: Monoraphid
BASIONYM: Achnanthidium coarctatum Brébisson ex W. Smith 1855
Frustules are heterovalvar. The valve margins are biundulate. The valve apices are rostrate, to only slightly expanded. The raphe valve face is concave about the transapical axis. On the raphe valve, the axial area is centered on the apical axis and may be gently curved. The central area is a distinct transverse fascia, that may be asymmetric. The proximal raphe ends are straight and slightly expanded. The striae are distinct, uniseriate and punctate. The striae are nearly parallel near the central valve becoming radiate near the ends. The rapheless valve is convex about the transapical axis and lacks a fascia. The narrow sternum is eccentric and positioned on the margin, except at the widest points of the valve. The striae are distinct, uniseriate and punctate. The striae are nearly parallel near the central part of the valve becoming radiate and curved near the ends.
As a result of the concave and convex valve faces, the frustule of A. coarctata is recurved in girdle view, where the raphe valve valve fascia is on concave side of the frustule.
Basionym: Achnanthidium coarctatum
Author: Brébisson ex W. Smith 1855
Length Range: µm
Striae in 10 µm:
Achnanthidium coarctatum, Bréb.
Valve linear-elliptical, constricted at the centre, attenuate, and constricted towards the rounded extremities. Striæ moniligorm, 24 in ·001”. Length of frustule ·0013” to ·0018”. v.v. Bréb in Kütz. Sp. Alg. p. 54 ad specim. authen. quæ dedit am. De Brébisson.
Fresh water. Cave near Royat ; Grassmere, Westmoreland, Aug. 1853, W. Sm.
Cite This Page:
Lowe, R., and Spaulding, S. (2011). Achnanthes coarctata. In Diatoms of the United States. Retrieved September 30, 2014, from http://westerndiatoms.colorado.edu/taxa/species/achnanthes_coarctata
Species: Achnanthes coarctata
Reviewer: Marina Potapova
Boyle, J.A., Pickett-Heaps, J.D. and D.B. Czarnecki. (1984). Valve morphogenesis in the pennate diatom Achnanthes coarctata. Journal of Phycology 20(4): 563-573.
Cleve, P.T. and Grunow, A. (1880). Beiträge zur Kenntniss der Arctischen Diatomeen. Kongliga Svenska-Vetenskaps Akademiens Handlingar, Vol: 17, Issue: 2, 121 pp., 7 pls.
Geitler, L. (1980). Zellteilung und Bildung von Innenschalen bei Hantzschia amphioxys und Achnanthes coarctata. Plant Systematics and Evolution 136:275-286.
The Environmental Protection Agency (EPA) western Environmental Monitoring and Assessment Program (EMAP) study was completed during the years 2000-2004 (see citations at bottom of this page). Over 1200 streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming) were selected for sampling based on a stratified randomized design. This type of design insures that ecological resources are sampled in proportion to their actual geographical presence. Stratified randomized design also allows for estimates of stream length with a known confidence in several “condition classes” (good or least-disturbed, intermediately-disturbed, and poor or most-disturbed) for biotic condition, chemistry and habitat.
Results are published in:
Johnson, T., Hermann, K., Spaulding, S., Beyea, B., Theel, C., Sada, R., Bollman, W., Bowman, J., Larsen, A., Vining, K., Ostermiller, J., Petersen, D. Hargett, E. and Zumberge, J. (2009). An ecological assessment of USEPA Region 8 streams and rivers. U.S. Environmental Protection Agency Region 8 Report, 178 p.
Stoddard, J. L., Peck, D. V., Olsen, A. R., Larsen, D. P., Van Sickle, J., Hawkins, C. P., Hughes, R. M., Whittier, T. R., Lomnicky, G. A., Herlihy, A. T., Kaufman, P. R., Peterson, S. A., Ringold, P. L., Paulsen, S. G., and Blair, R. (2005). Environmental Monitoring and Assessment Program (EMAP) western streams and rivers statistical summary. U.S. Environmental Protection Agency Report 620/R-05/006, 1,762 p.
Stoddard, J. L., Peck, D. V., Paulsen, S. G., Van Sickle, J., Hawkins, C. P., Herlihy, A. T., Hughes, R. M., Kaufman, P. R., Larsen, D. P., Lomnicky, G. A., Olsen, A. R., Peterson, S. A., Ringold, P. L., and Whittier, T. R. (2005). An ecological assessment of western streams and rivers. U.S. Environmental Protection Agency Report 620/R-05/005, 49 p.