Credit: Marina Potapova
Rhoicosphenia abbreviata on Cladophora filament, Lake Okoboji, Iowa
Rhoicosphenia abbreviata
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Category
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Length Range10–55 µm
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Width Range4–8 µm
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Striae in 10 µm15-20
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SynonymsGomphonema abbreviatum C.Agardh
Rhoicosphenia curvata (Kütz.) Grunow
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ContributorMarina Potapova - May 2009
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ReviewerSam Rushforth - May 2010
Identification
Description
Valves are clavate. with rounded apices. Frustules are heteropolar, appearing bent in girdle view. 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. The central area is oval to elliptic. A pseudoseptum is present at both poles on valve margins. Striae are uniseriate. Areolae are apically elongated. Cells occur on stalks, forming colonies.
Autecology
Cells are found in freshwater high in ionic content and in brackish waters.
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Size Range, µm3
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Motility
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Attachment
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Habitat
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BCG
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Waterbody
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Distribution
- Learn more about this
Original Description
G. abbreviatum, pedunculo subramoso cymbellis conicis fastigiatis breviore.
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BasionymGomphonema abbreviatum
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AuthorAgardh 1831
Original Images
Citations & Links
Citations
Links
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Index Nominum Algarum
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GenBank
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North American Diatom Ecological DatabaseNADED ID: 57002
Updates
Dec 21, 2024 - Change in species circumscription
Investigation of Rhoicosphenia in North America has resulted in recognition of species in addition to R. abbreviata. Previously, the concept presented here was broad and included R. californica. An image of R. californica was removed and the text adjusted to reflect a more narrow concept. A pdf copy of the original species page is available upon request. - S. Spaulding
Cite This Page
Potapova, M. (2009). Rhoicosphenia abbreviata. In Diatoms of North America. Retrieved December 21, 2024, from https://diatoms.org/species/44479/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.
Rhoicosphenia abbreviata
- Valves club-shaped
- Pseudoseptae present
- Raphe valve with full raphe system
- Rudimentary raphe valve with short raphe slits
- Central area oval
Valves are clavate, or club-shaped with rounded ends. In girdle view, frustules are distinctly arched. In valve view, the 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 short raphe slits.