TEST METHOD: Plankton Identification for Saltfields

Revised: 25 April 2004 (clarified the use of this key)

This key is only of use for saltfield plankton counts. The groups it identifies may not occur, or may be too coarsely grouped for usefulness, in other environments.

Determine whether the organism is a plant (algae), an animal (zooplankton) or debris (bacterial debris, crystals of gypsum or salt, indeterminate “stuff”). If zooplankton, split into the various types of “brine shrimp and “other zooplankton”. If plant, use the key below to determine group.

Artificial Key for sorting planktonic algae when doing a Saltfield Algae Count

1.       The cell has one or more flagellae....................................................................................... 2.

          The cell has no flagellae..................................................................................................... 5.

2.       The cell has a waist and heavy coat, red or brown.......................................... Dinoflagellate

          The cell has no waist.......................................................................................................... 3.

3.       The cell has 2 flagellae, a cup-shaped chloroplast  & red eye-spot .....................................  4.

          The cell is not as above................................................................. Chlorophytes and others

4.       The cell is small, pear-shaped and green...................................................... green Dunaliella

          The cell is large, oval-shaped and red.............................................................. red Dunaliella

5.       The cell is bright green, either dark or light.......................................................................... 6.

          The cell is some other colour............................................................................................... 7.

6.       The cell is tiny with no internal details visible......................................................... Microalgae

          The cell is large, shape various, internal details visible...................... Chlorophytes and others

7.       The cell is blue-green (cyan) with little internal detail........................................................... 8.

          The cell is some other colour.............................................................................................. 9.

8.       The cell is solitary, a rod-shaped coccus (a squarish oval) .............................. Synechococcus

          The cell is filamentous, colonial or not a rod-shaped coccus...................... Other cyanophytes

9.       The cell is large, red and circular.................................................................... Dunaliella cyst

          The cell is golden or clear with a clear silica shell........................................................ Diatom

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