Pediastrum duplex Meyen

Taxonomic Identification

Pediastrum duplex Meyen is a species of freshwater green alga belonging to the genus Pediastrum, and it is the type species of this genus.

Colony Traits

This alga forms nonmotile, flat, circular coenobia (colonies) that have a fixed number of cells. Most colonies hold 8 to 32 cells, while colonies with 4, 64, or 128 cells are rare.

Colony Intercellular Features

There are small holes between the cells in a colony, and these holes have a smaller diameter than the cells themselves.

Individual Cell Shape

The individual cells are polygonal, with a distinctly rectangular outline and concave sides.

Outer Cell Structure

The outer cells of the coenobium each have two triangular lobes that are longer than the cell body. The tips of these lobes bear very short rosettes, which may also have fine bristles.

Cell Wall Characteristics

The cell wall is most often smooth, but it can sometimes have a clear sculptured texture.

Reproduction

Pediastrum duplex primarily reproduces asexually through the formation of autocolonies, though sexual reproduction has also been observed.

Distribution and Habitat

It is a very common component of freshwater phytoplankton and has a cosmopolitan distribution.

Fossil Record

Because its cell walls are resistant to decay, remains of Pediastrum duplex cell walls have been recovered from Holocene lake sediments.