Encyonema reimeri

Spaulding, Pool et Castro 2010      Category: Asymmetrical biraphid
BASIONYM: Encyonema reimeri Spaulding, Pool et Castro 2010

REPORTED AS: Cymbella muelleri ((Patrick and Reimer 1975, pl.7, fig. 1)) 

Encyonema prostratum


Encyonema temperei

LM scalebar = 10 µm = 40 pixels.


Contributor: Sarah Spaulding - April 2010
Length Range: 30-75 µm
Width Range: 17-22 µm
Striae in 10 µm: 10


Valves are strongly dorsi-ventral. The dorsal margin is broadly arched, while the ventral margin is expanded. Valve length is 30-75 μm; breadth is 17-22 μm. The valve apices are acute. The axial area is relatively broad in the central part, narrowing at the valve ends. The raphe branches have a slight arch towards the ventral margin. Each raphe branch is positioned nearly centrally within the axial area. Proximal raphe ends are slightly expanded and dorsally deflected. Distal raphe ends curve slightly to the dorsal margin, but are deflected ventrally near the valve apices. The dorsal striae are divergent. Externally, the rows of dorsal areolae closest to the central area are oval, and become lineolate, the length of the lineolae becoming greater towards the dorsal margin. Dorsally, central striae number 10 in 10 μm and distal striae number 5 in 5 μm. Ventrally, central striae number 8 in 10 μm, and distal striae number 6 in 5 μm. The density of areolae within a central, dorsal stria is 7-8 in 5 μm. The striae continue continue onto the mantle, but stop short of the valve margin. Internally, the striae are lineolate and positioned between thickened internal costae. The proximal raphe ends are deflected dorsally at a 90° angle. Distally, the raphe ends at a terminal nodule. A single chloroplast possesses two lobes and ventral fold.

Original Description

Basionym: Encyonema reimeri
Author: Spaulding, Pool et Castro 2010
Length Range: 30-75 µm
Width Range: 17-22 µm
Striae in 10 µm: 10

Original Description

Valvulae sunt valde dorsiventrales. Dorsualis margo ample arcuata est, sed ventralis margo inflatosa est. Valvulae longitudo 30-75 μm est; amplitudo 17-22 μm est. Valvulae terminationes acutae sunt. Axialis superficies est relative ampla in centrali valvula et astringitur in extrema valvula. Suturae ramificationes levem habent arcum ad ventralem marginem. Unaquaeque suturae ramificatio posita est fere centrali positione intra axialem superficiem. Suturae extrema proxima leviter sunt expansi et dorsualiter deflexi. Suturae extrema distalia suturae curvaminis leviter inflectuntur marginem ad dorsualem, sed ventraliter sunt deflexa prope valvulae apices. Dorsuales striae sunt in diversum vergentes. Externe, primae series sunt ovales fiuntque lineolatae, maiorque fit lineolatarum longitudo ad dorsualem marginem. Dorsualiter, striae numeris 10 sunt in 10 μm; centraliter sunt 9 in 10 μm. Striae continuantur super dorsualem marginem valvulae. Interne, striae lineolatae sunt et positae intra cubicula, cum internis costis super dorsualem marginem spissatae. Suturae extrema proxima dorsualiter sunt deflexa angulo 90 graduum. Distaliter, sutura terminali nodulo finit. Chloroplasti duas habent auriculas, ventrali plica.

Original Images

Original text and images reproduced with permission by Proceedings of the Academy of Natural Sciences of Philadephia.

Cite This Page:
Spaulding, S. (2010). Encyonema reimeri. In Diatoms of the United States. Retrieved September 01, 2015, from http://westerndiatoms.colorado.edu/taxa/species/encyononema_reimeri

Species: Encyonema reimeri

Contributor: Sarah Spaulding

Reviewer: Mark Edlund


Spaulding, S.A., Pool, J., Castro, S. and Hinz, F. (2010). Species within the genus Encyonema Kützing, including two new species Encyonema reimeri sp. nov. and E. nicafei sp. nov. and E. stoermeri nom. nov., stat. nov. Proceedings of the Academy of Natural Sciences of Philadelphia 160(1):57-71. 10.1635/053.160.0107

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)


Autecology Discussion

The colonies of Encyonema are within mucilagious tubes.


Encyonema reimeri living cells growing in mucilaginous tubes. Such tubes are typical for species within Encyonema. These tubes are shown surrounded by the cyanobacteria Planktothrix.

Credit/Source: Kalina Manoylov

Another example of E. reimeri growing in mucilage tubes. The cells are able to move independently within the tubes.

Credit/Source: Kalina Manoylov

A single living cell of E. reimeri showing the chloroplast. The chloroplast structure of Encyononema is characteristic; it possesses a fold on the ventral side of the valve.

Credit/Source: Justin Pool