Diatoms of North AmericaDiatoms of North America

Kurtkrammeria weilandii

(Bahls) Bahls 2015

Kurtkrammeria Weilandii Guide
  • Category
    Asymmetric Biraphid
  • Length Range
    33.0-72.0 µm
  • Width Range
    7.5-9.7 µm
  • Striae in 10 µm
    12-14 at the valve center, 15-18 near the apices

Identification

Kurtkrammeria weilandii LM4 Kurtkrammeria weilandii LM5 Kurtkrammeria weilandii LM7 Kurtkrammeria weilandii LM6 Kurtkrammeria weilandii LM3 Kurtkrammeria weilandii LM1 Kurtkrammeria weilandii LM2
View image metadata
Kurtkrammeria weilandii SEM4 Kurtkrammeria weilandii SEM3 Kurtkrammeria weilandii SEM2 Kurtkrammeria weilandii SEM1

Description

Valves are rhombic-lanceolate and slightly dorsiventral. Apices are rounded and weakly subrostrate, or apices are not protracted. The axial area is narrow. The central area is small and defined by a shortened median stria on the ventral side. The raphe is centrally located and lateral, becoming filiform at the proximal and distal ends. Proximal raphe ends are weakly expanded and deflected dorsally. Distal raphe fissures are comma-shaped, concave to the ventral margin. Striae are radiate near the valve center, becoming parallel then convergent near the apices, The median striae on the dorsal and ventral sides are more distant from their mates than the remaining striae. A single stigma lies at the proximal end of the median dorsal stria.

This is the generitype for Kurtkrammeria. It possesses all of the features that may be found in Kurtkrammeria, but not in Encyonopsis, including a stigma, apically elongate areolae, convergent striae at the apices, and internal anastomosing virgae and external apical pore fields at both poles. At first glance, K. weilandii might be mistaken for a species of Gomphonema, e.g., Gomphonema gracile Ehrenberg. However, Gomphonema species are not symmetric to the transapical axis and the raphe branches are unequal in length.

Autecology

Like other species of Kurtkrammeria, K. weilandii prefers cold oligotrophic waters with circumneutral pH and low conductivity. There are 28 records of K. weilandii in the Montana Diatom Collection, nearly all of them from ponds and small lakes in the Cascade and Northern Rocky Mountains. Most records consist of one to a few specimens on a strewn mount, but K. weilandii was the dominant diatom species in a small meltwater pond on Anderson Pass in Olympic National Park, Washington (photo below). This pond is at 1361 m a.s.l. elevation, measures about 15 m in diameter, and is less than 1 m deep. The water in this pond is essentially snowmelt and rainwater. To date, K. weilandii has been reported only from North America.

Goat Rocks Pond Img 5462
Credit: Craig Weiland, Adventurers and Scientists for Conservation
Goat Rocks Pond, Cascade Mountains, Washington: Type locality for Kurtkrammeria weilandii.
Olympics Meltwater Pond1 Ryan Davis
Credit: Ryan Davis, Adventurers and Scientists for Conservation
Small meltwater pond at Anderson Pass in Olympic National Park, Washington. Kurtkrammeria weilandii was the dominant diatom species at this site.

Original Description

Valves lanceolate, not or slightly dorsiventral. Apices rounded, weakly subrostrate or not protracted. Valve length 33.0–72.0 μm; valve width 7.5–9.7 μm. Axial area narrow. Central area small, defined by a shortened median stria on the ventral side. Raphe lateral, proximal and distal ends filiform. Proximal raphe ends weakly expanded and deflected dorsally. Distal raphe fissures comma-shaped, concave to the ventral margin. Striae radiate, becoming parallel then convergent near the apices, 12–14 in 10 μm at valve center, 15–18 in 10 μm near the apices. The median striae on the dorsal and ventral sides are more distant from their mates than the remaining striae. A single stigma lies at the proximal end of the median dorsal stria.

  • Basionym
    Encyonopsis weilandii
  • Author
    Bahls 2013
  • Length Range
    33.0-72.0 µm
  • Width
    7.5-9.7 µm
  • Striae in 10µm
    12-14 at valve center, 15-18 near the apices

Original Images

Encyonopsis weilandii orig illus 2
Encyonopsis Weilandii Origdesc001

Cite This Page

Bahls, L. (2015). Kurtkrammeria weilandii. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/kurtkrammeria_weilandii

Responses

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