Introduction to Freshwater Algae - Freshwater Algae: Identification, Enumeration and Use as Bioindicators - page 6

Table 1.2 Major Divisions of Freshwater Algae: Microscopical Appearance.

Algal Division
(Phylum)

Index of
Biodiversity a

Typical Morphology of
Freshwater Species

Motility (Vegetative
Cells/Colonies) Typical Colour Typical Examples

1. Blue-green algae
( Cyanophyta )

297 Blue-green Microscopic or visible - usually

colonial

Buoyancy regulation
Some can glide

Synechocystis
Microcystis

2. Green algae
( Chlorophyta )

992 Grass-green Microscopic or visible - unicellular

or ilamentous colonial

Some unicells and
colonies with lagella

Chlamydomonas
Cladophora

3. Euglenoids
( Euglenophyta )

124 Various colours Microscopic - unicellular Mostly with lagella Euglena

Colacium

4. Yellow-green algae
( Xanthophyta )

73 Yellow-green Microscopic - unicellular or

ilamentous

Flagellate zoospores and
gametes

Ophiocytium
Vaucheria

5. Dinolagellates
( Dinophyta )

54 Red-brown Microscopic - unicellular All with lagella Ceratium

Peridinium

6. Cryptomonads
( Cryptophyta )

15 Various colours Microscopic - Unicellular Mostly with lagella Rhodomonas

Cryptomonas

7. Chrysophytes
( Chrysophyta )

115 Golden brown Microscopic - unicellular or

colonial

Some with lagella Mallomonas

Dinobryon

8. Diatoms
( Bacillariophyta )

1652 Golden brown Microscopic - unicellular or

ilamentous colonies

Gliding movement on
substrate

Stephanodiscus
Aulacoseira

9. Red algae
( Rhodophyta )

22 Red Microscopic or visible - unicellular

or colonial

Non-motile Batrachospermum

Bangia

10. Brown algae
( Phaeophyta )

2 Brown Visible - multicellular cushions

and crustose thalli

Non-motile Pleurocladia

Heribaudiella

a Biodiversity: number of species of freshwater and terrestrial algae within the British Isles.