Encyonopsis microcephala | Species - Diatoms of North America

Category

Asymmetric Biraphid
Length Range

10-16 µm
Width Range

3-4 µm
Striae in 10 µm

22-24

Contributor

Pat Kociolek - Mar 2011
Reviewer

Sarah Spaulding - Aug 2013

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Identification

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Description

Valves are asymmetrical to the apical axis, the dorsal margin is distinctly convex, then ventral margin is slightly convex. The apices are protracted and relatively large compared to the size of the valve, broadly rounded, and curved slightly towards the dorsal margin. The axial area is narrow. The central area is indistinct, when present it is formed by a short stria on the ventral margin. The raphe is filiform and slightly arched towards the dorsal margin. Striae are parallel on the dorsal margin, radiate on the ventral margin.

Autecology

Size Range, µm3

11-100
Motility

Moderately motile
Attachment

Prostrate
Habitat

Benthic
Colony

Solitary
BCG

BCG 3
Waterbody

Inland
Distribution

Western rivers 2004 California coastal rivers 2017 Northeast lake sediments
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Original Description

C. microcephala Grun. (Atl. Ρ1. VΙΙΙ fig. 36-39 — in Type Νο 211.) Valves assez étroitement lanceolées, à peine cymbiformes, à extrémités fortement rostrées-capitées ; raphé faiblement arqué ; stries délicates, 24 dans les grandes formes, 28 à 30 dans les petites formes. Longueur : 1 1/2 à 2 1/3 c.d.m.

Basionym

Cymbella microcephala
Author

Grunow 0

Original Images

Citations & Links

Citations

Krammer, K. (1997) Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 1. Allgemeines und Encyonema Bibliotheca Diatomologica 36: 1-382

Cite This Page

Kociolek, P. (2011). Encyonopsis microcephala. In Diatoms of North America. Retrieved December 16, 2024, from https://diatoms.org/species/46354/encyonopsis_microcephala

Responses

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