Valves are rhombic-lanceolate with attenuate apices. The striae are uniseriate, slightly radiate in the center and almost parallel or slightly convergent at the ends. Areolae are slit-shaped and number 42-50 in 10 mm. The central area is transverse and rectangular. The raphe is filiform and has tear-drop shaped distal and proximal ends. A row of areolae is present at the valve apex. The valvocopula are deep.
Hippodonta gravistriata have been reported from the tidal zones of the Sabine River, Texas, and from the Patuxent and Potomac Rivers, Maryland.
Potapova, M. (2013). Hippodonta gravistriata. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/hippodonta_gravistriata
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Hippodonta gravistriata 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.