Diatoms of North AmericaDiatoms of North America

Frustulia latita

Graeff and Kociolek 2011

Frustulia Latita Guide
  • Category
    Symmetric Biraphid
  • Length Range
    32.0-48.0 µm
  • Width Range
    8.0-10.0 µm
  • Striae in 10 µm
    30-32 at the center, 33-35 at the ends
  • Reported As
    Frustulia weinholdii (Patrick and Reimer 1966)

Identification

Frustulia latita LM1 Frustulia latita LM2 Frustulia latita LM3 Frustulia latita LM3 Frustulia latita LM5
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Frustulia latita SEM2 Frustulia latita SEM1

Description

The valves are linear-lanceolate with slightly rostrate rounded apices. The striae are parallel or slightly radiate at the valve center, parallel along the length of the valve, and convergent at the ends of the valve. Areolae comprising the striae are round or oval. The areolae near the poles are relatively small. Elongated areolae are common at in the transverse depression found at the external raphe ends. At the central area, the striae are variable in length, giving the central a unique and highly asymmetric shape. Internally, the longitudinal ribs terminate well before both the helictoglossae and central nodule.

F. latita is a species that has been separated from the broad taxon concept of F. weinholdii established by Patrick and Reimer (1966) where they described the apices of F. weinholdii as round to capitate. At least two additional species have since been separated from F. weinholdii, including those populations with capitate apices. Under the broad concept of the taxon, reports of F. weinholdii have been numerous in the United States.

Original Description

Valves linear-lanceolate with slightly rostrate rounded apices. The striae are parallel or slightly radiate at the valve center, parallel along the length of the valve, and convergent at the ends of the valve. Areolae comprising the striae are round or oval, and the areolae near the poles are relatively small. Elongated areolae are common in the transverse depression found at the external raphe ends. The central area is similar to that seen in F. weinholdii, where it is expanded to accommodate the curved external proximal raphe ends, and a triangular stirae arrangement can be present. Internally, the areolae are occluded. The raphe branches are curved, slightly. Internally, the longitudinal ribs terminate well before both the helictoglossae and central nodule.

The cingulum is comprised of a closed valvocopula with obvious rows of poroids at the apices. In addition, there are a few open girdle bands with one or two rows of poroids. One end of the open girdle band is widened significantly. A break in the valvocopula is sometimes present, revealing an underlying row of poroids and protuberances.

  • Author
    Graeff and Kociolek 2011
  • Length Range
    32.0-48.0 µm
  • Width
    8.0-10.0 µm
  • Striae in 10µm
    30-32 at the center, 33-35 at the ends

Cite This Page

Graeff, C. (2011). Frustulia latita. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/frustulia_latita

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Frustulia latita 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.