Fragilaria recapitellata
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Category
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Length Range14.6-26.6 µm
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Width Range4.1-5.6 µm
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Striae in 10 µm16-20
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SynonymsSynedra capitellata Grunow in Van Heurck
Fragilaria capitellata (Grunow in Van Heurck) Peterson
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ContributorIan Bishop, Sarah Spaulding - Aug 2014
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ReviewerMark Edlund - Oct 2014
Identification
Description
Valves are wide and linear, with highly constricted, capitate ends. The axial area is narrow and widens slightly near the central area. The central area is unilaterally expanded to the valve margin. Stria density is uniform across the valve. A single rimoportula is present at one end of the valve. A porefield is present at each apex, positioned on the valve mantle and composed of several transapically aligned rows of pores extending slightly onto the valve face. In valve view, frustules are rectangular.
Spines were not observed in SEM, nor were long, band shaped colonies.
The name, F. recapitellata is a new name for Fragilaria capitellata (Grunow in Van Heurck) Petersen 1946 (non Lauby 1910). Note that the taxon illustrated here conforms more to the taxon illustrated in Metzeltin et al. (2009) than in the original description of Synedra capitellata Grunow in Van Heurck 1881.
Autecology
In North America, Fragilaria recapitellata has been documented in the Great Lakes (Stoermer et al, 1999) and in rivers in the Central Sierra Nevada (USGS NAQWA Survey).
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Size Range, µm3
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Motility
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Habitat
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Waterbody
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Original Description
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BasionymSynedra capitellata
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AuthorGrunow in Van Heurck 1881
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Striae in 10µm15-18
Original Images
Citations & Links
Citations
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Publication Link: 10.11646/phytotaxa.231.1.1
Links
Updates
Dec 11, 2024 - Extension of Size Range
Prior to this date, length for this taxon was documented as 19.1-29.1 µm. This range was expanded to include smaller specimens found in a separate population by the contributor. The smallest image was taken from this latter population. - I. Bishop
Cite This Page
Bishop, I., Spaulding, S. (2014). Fragilaria recapitellata. In Diatoms of North America. Retrieved December 11, 2024, from https://diatoms.org/species/50127/fragilaria_capucina_var._capitellata
Responses
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Fragilaria recapitellata 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.
Fragilaria recapitellata
- Capitate ends
- Narrow axial area
- Central area expanded on one side of valve
- Rimoportula present
Valves are wide and linear with capitate ends. Stria density is uniform across the valves, with 16-20 striae in 10 μm. The axial area is narrow and widens slightly near the central area. The central area unilaterally expands toward the valve margin. A single rimoportula is present. Spines are absent.