Shallow lake

Many green algae were found in this shallow lake just a few miles from New York City.  Although you can’t always see them, microscopic green algae can be found in the open water and among the plants in the lake.

Freshwater lakes often contain dozens of species of green algae.  Some of them live only in the open water while others grow one the bottom of the lake or among the plants.  Some freshwater green algae are very large – some even look like plants – but most freshwater green algae are too small to see without a microscope.

These small algae can be collected with fine mesh nets or by sampling the water around aquatic plants. The species below are just some of the many species of microscopic algae that can be found in freshwater lakes.

Left to right: Desmidium baileyi (Zygnematophyceae), Staurastrum leptocladum var. cornutum (Zygnematophyceae), and Nephrocytium agardhianum (Chlorophyceae). Desmidium and Staurastrum are both members of the species-rich freshwater desmids.  The desmids are typically composed of cells with two halves called semicells.  This is more obvious in Staurastrum than Desmidium.

Nephrocytium is a colonial member of the Chlorophyceae which is composed of curved cells in a common matrix. It can be found in the plankton, but is often found growing among the leaves of aquatic plants such as Utricularia or Myriophyllum.