Microscopes

Pond Life – Holoplankton

MATERIALS: microscope, live mount, slides, dropper, cover slips, reflecting and transmitting light

EXERCISE I. Looking at the picture on the left, what is the main group of organisms found?

EXERCISE II. In the space below draw as many members of the holoplankton that you can identify. Use the chart to help in identification. Use other sheets of paper if you can identify more than the space below.

Microscopic autotrophic organisms (i.e. algae)

Name

Picture

Characteristic

Taxonomy

Green algae (with flagella, small)
<.05 mm

1. flagella
2. small
3. solitary
4. rapid movement

Phylum Chlorophyceae
i.e. Chlamyolomonas sp.

Green algae (with flagella)
.5-2mm

1. spherical
2. colonial
3. with two flagella

Phylum Chlorophyceae
i.e. Volvox sp.

Green algae
(no flagella)
<.5 mm

1. spherical to conical
2. not attached to surface
3. no movement

Phylum Chlorophyceae
i.e. Pediastrum sp.

Filamentous green algae
<.1 mm – cms

1. non branching
2. chains of cells with chloroplast
3. no flagella

Phylum Gamophyceae
i.e. Zygnema sp.
Spirogyra sp.

Desmids
<.5 mm

1. green
2. no flagella
3. mainly solitary, some colonial
4.various shapes
5. two semi-cell, mirror image

Phylum Gamophyceae
i.e. Desmidium sp
Closterium sp.

Diatoms
<.5 mm

1. one cell
2. slow gliding motion
3. solitary or colonial
4.cell wall (frustules) made of silica

Phylum Bacillariophyceae
i.e. Pennales, Centric