Diatoms of North AmericaDiatoms of North America

Encyonema sinicum

Krammer 1997

Encyonema sinicum guide
  • Category
    Asymmetric Biraphid
  • Length Range
    31.6-84.8 µm
  • Width Range
    13.6-22.6 µm
  • Striae in 10 µm
    10-12 dorsal at valve center; 11-12 dorsal at valve apices; 8-10 ventral at valve center; 10-14 ventral at valve apices

Identification

Encyonema sinicum LM1 Encyonema sinicum LM2 Encyonema sinicum LM3 Encyonema sinicum LM4 Encyonema sinicum LM5
View image metadata

Description

Valve is dorsiventral with rounded, wedge-shaped apices. Dorsal margin is strongly arched. Ventral margin is weakly convex with gibbous center. Axial area is wide, with a slightly wider central area. The central area is asymmetric, rounded on the dorsal side and flat on the ventral side.

The raphe is lateral, narrowing near the proximal and distal ends. Proximal raphe ends are dorsally deflected and terminate in weakly inflated pores. Distal raphe ends are comma-shaped and deflected ventrally.

Dorsal striae are radiate. A stigmoid at the end of the median dorsal stria is absent. Ventral striae are parallel to slightly radiate at the valve center and about 1/4 the valve width, transitioning to radiate, then to parallel or slightly convergent near the apices. Areolae number 16-20 in 10 µm.

Autecology

This species was described from fossil material in Hainan, China.

It has been reported from a few small to very large lakes (Lake Tahoe) in the western United States.

039 11
Credit: Loren Bahls
Mann Lake, Harney County, eastern Oregon.
Encyonema reimeri Sensu Lato Copy
Credit: Loren Bahls
Taxa in the Encyonema reimeri group from the western United States.

Original Description

(65) Encyonema sinicum Krammer nov. spec. (Fig. 72:1-9)

Valvae valde dorsiventrales, margine dorsali valde convexa, margine ventrali leviter convexa, ad centrum valvis maioribus leniter tumidis, apicibus acute rotundatis, non protractis, 34-72 µm longae, 14-20 µm latae. Area axialis lata, lanceolata, ad nodulum centralem versus dilatata, area centralis nulla. Raphe excentrica, ad aream centralem atque ad apices sensim filiformis, alibus locis lata, terminis proximalibus at latus dorsalis inclinatis, fissuris distalibus in latus ventralis deflexis. Stigmoidea nulla. Striae transapicales distincte punctatae-lineolatae, punctae 14-18 in 10 µm. Striae in latere dorsali modice radiantes, 9- 10 in 10 µm.

Locus typicus: Hainan, China, fossilis.

Typus: Praep. 1027 IOK (Isotypi 1028-1031 IOK).

  • Author
    Krammer 1997
  • Length Range
    34-72 µm
  • Width
    14-20 µm
  • Striae in 10µm
    9-10

Original Images

Encyonema Sinicum Origimag001
Encyonema Sinicum Origdesc001

Cite This Page

Bahls, L. (2018). Encyonema sinicum. In Diatoms of North America. Retrieved December 26, 2024, from https://diatoms.org/species/94638/encyonema-sinicum

Responses

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

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