Fragilaria tenera

(W. Smith) Lange-Bertalot 1980      Category: Araphid
BASIONYM: Synedra tenera W. Smith 1856

Fragilaria synegrotesca


Fragilaria vaucheriae

LM scalebar = 10 µm = 80 pixels.


Contributor: Eduardo Morales | Barry Rosen - May 2013
Length Range: 50-75 µm
Width Range: 2.0-2.5 µm
Striae in 10 µm: 15-17


Valves are narrow and lanceolate, with attenuated, capitate apices. The mid-valve has convex margins. In girdle view, frustules are somewhat rectangular and wider at mid-valve. The axial area is lanceolate and in some specimens a distinct fascia is present in the central area. Striae are distinct, but areolae are resolvable under LM. Striae are parallel throughout the valve and extend midway onto the valve mantle. Costae are wider than the striae.

Original Description

Basionym: Synedra tenera
Author: W. Smith 1856
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Morales, E., and Rosen, B. (2013). Fragilaria tenera. In Diatoms of the United States. Retrieved November 30, 2015, from

Species: Fragilaria tenera

Contributor: Eduardo Morales | Barry Rosen

Reviewer: Rex Lowe


Lange-Bertalot, H. (1980). Zur systematischen Bewertung der bandförmigen Kolonien bei Navicula und Fragilaria. Kriterien für die Vereinigung von Synedra (subgen. Synedra) Ehrenberg mit Fragilaria Lyngbye. Nova Hedwigia 33: 723-787.

Smith, W. (1856). Synopsis of British Diatomaceae. John Van Voorst, London 1856. 2: 107pp., pls. 32-60, 61-62, A-E.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA

California Academy of Sciences (CAS)

Fragilaria tenera CAS

North American Diatom Ecological Database (NADED)

NADED ID: 34105

Autecology Discussion

Cells may form small colonies, joined by linking spines.