• Category
  • Length Range
    30-42 µm
  • Width Range
    12-15 µm
  • Striae in 10 µm
    17 in the center, 22 at the ends

Identification

Description

Valves are distinctly capitate with broadly rounded margins. The axial area is narrow, expanding to rounded central area. Proximal raphe ends are slightly expanded on external surface of the valve. Distal raphe ends are curved in the same direction. Striae are punctate, radiate and curve from the margin toward the center of the valve. Striae number 17 in 10 μm in the center, becoming finer at the ends (22 in 10 μm). Areolae number 16 in 10 μm and are round toward valve ends and transversely elongate near the center valve.

Autecology

Populations of C. hawai'iensis are primarily from subaerial habitats Hawai’i.

Original Description

Valves are distinctly capitate with broadly rounded margins (Figs. 19-24). Valves 30-42 μm long, 12-15 μm wide. Axial area narrow expanding to rounded central area. Proximal raphe ends slightly expanded on the valve surface in pyriform depression (Fig. 17), Distal raphe ends are curved in the same direction (Fig. 23). Internally, raphe ends are anchor-shaped (Fig. 24). Striae punctate, and radiate, curving from the margin toward the center of the valve. Striae 17 in 10 μm in the center becoming finer at the ends (22/10 μm). Puncta 16/10 μm round toward valve ends, transversely elongated near center.

  • Author
    R.L.Lowe and A.R.Sherwood 2010
  • Length Range
    30-42 µm
  • Width
    12-15 µm
  • Striae in 10µm
    17 in the center, 22 at the ends

Cite This Page

Lowe, R. (2011). Cosmioneis hawai'iensis. In Diatoms of North America. Retrieved July 23, 2018, from https://diatoms.org/species/cosmioneis_hawaiiensis

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Cosmioneis hawai'iensis 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.