Rhoicosphenia abbreviata

(Agardh) Lange-Bertalot 1980      Category: Asymmetrical biraphid
BASIONYM: Gomphonema abbreviatum Agardh 1831
SYNONYM(S): Gomphonema abbreviatum Agardh | Rhoicosphenia curvata (Kützing) Grunow 

Rexlowea navicularis

 

Rhopalodia gibba
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LM scalebar = 10 µm = 80 pixels.

Observations

Contributor: Marina Potapova - May 2009
Length Range: 10–55 µm
Width Range: 3–8 µm
Striae in 10 µm: 15-20

Description

Cells occur on stalks, forming colonies. Frustules are heteropolar, bent in girdle view. Valves are linear-lanceolate, 3-8 µm wide, 10-55 µm long. The ventral valve is concave, with a fully developed raphe system. The dorsal valve is convex, with short raphe slits situated close to the poles. A pseudoseptum is present at both poles on valve margins. Striae are uniseriate, 15-20 in 10 µm. Areolae are apically elongated.

Original Description

Basionym: Gomphonema abbreviatum
Author: Agardh 1831
Length Range: µm
Striae in 10 µm:

Original Description

G. abbreviatum, pedunculo subramoso cymbellis conicis fastigiatis breviore.

Original Images

Cite This Page:
Potapova, M. (2009). Rhoicosphenia abbreviata. In Diatoms of the United States. Retrieved May 21, 2013, from http://westerndiatoms.colorado.edu/taxa/species/Rhoicosphenia_abbreviata

Species: Rhoicosphenia abbreviata

Contributor: Marina Potapova

Reviewer: Sam Rushforth

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Image Credit: Marina Potapova

  1. Valves elongate and club-shaped
  2. Pseudoseptum present at each valve end
  3. Raphe valve concave with fully developed raphe system
  4. Rudimentary raphe valve convex with very short raphe slits
  5. Valves distinctly arched in girdle view

Valves linear-lanceolate. Frustules in girdle view arched (bent). In valve view, this arch prevents resolution of the entire valve face at one level of focus. Pseudoseptum present at each pole. One valve possesses a fully developed raphe system, the other valve possesses very short raphe slits.

Compare

Rhoicosphenia abbreviata can be distinguished from various species of the genus Gomphonema by the strong arch of the valve (as seen in girdle view), the reduced raphe on the dorsal valve, and the presence of more developed pseudoseptae.

Gomphonema spp.

Citations

Agardh, C.A. (1831). Conspectus Criticus Diatomacearum. Part 3. Lundae. Litteris Berlingianis. pp. 33-48.

Lange-Bertalot, H. (1980). Ein Beitrag zur Revision der Gattungen Rhoicosphenia Grun., Gomphonema C. Ag., Gomphoneis Cl. Botaniska Notiser 133:585-594.

Mann, D.G. (1982). Structure, life history and systematics of Rhoicosphenia (Bacillariophyta) I. The vegetative cell of Rh. curvata. Journal of Phycology 18: 162-176.

Mann, D.G. (1982). Structure, life history and systematics of Rhoicosphenia (Bacillariophyta) II. Auxospore formation and perizonium structure of Rh. curvata. Journal of Phycology 18: 264-274.

Mann, D.G. (1984). Structure, life history and systematics of Rhoicosphenia (Bacillariophyta) V. Initial cell and size reduction in Rh. curvata and description of of the Rhoicospheniaceae fam. nov. Journal of Phycology 20: 544-555.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA
Original INA

California Academy of Sciences (CAS)

Rhoicosphenia abbreviata CAS

North American Diatom Ecological Database (NADED)

NADED ID: 57002

Autecology Discussion

fresh water of high ionic content or brackish water

Images

Rhoicosphenia abbreviata on Cladophora filament, Lake Okoboji, Iowa

Credit/Source: Marina Potapova

Habits

Size Range

101-1000 µm3 (ie Amphora veneta)
1001-10,000 µm3 (ie Diatoma vulgaris)

Motility

weakly motile (e.g. Actinella)

Attachment

vertical (e.g. stalks)

Habitat

benthic

Colony

EMAP Assessment

Sampling for 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). Streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming). Over 1200 sites on 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.

EMAP Distribution

Rhoicosphenia abbreviata

Distribution

The distribution map represents the relative abundance of this Rhoicosphenia abbreviata in the western EMAP study. Relative abundance is a measure of the proportion of cells of this species based on a "fixed count" of 300 total diatom cells counted and identified. Each of the western EMAP sample sites is shown, either with a black dot for sites where Rhoicosphenia abbreviata was not recorded, or with a red circle indicating the relative abundance of Rhoicosphenia abbreviata.

Note that the size of the proportional symbols varies between species to help show both abundant and rare species.

Scale for the map to the left

EMAP Response Plots

Rhoicosphenia abbreviata

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Rhoicosphenia abbreviata from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.

EMAP citations

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.