Ponds and Lakes

Major Algae Groups

Blue-green algae are the slimy stuff. Its cells lack nuclei and its pigment is scattered. Blue-green algae are not actually algae, they are bacteria.

Green algae cells have nuclei and the pigment is distinct. Green algae are the most common algae in ponds and can be multicellular.

Euglenoids are green or brown and swim with their flagellum, too. They are easy to spot because of their red eye. Euglenoids are microscopic and single celled.

Dinoflagellates have a flagella and can swim in open waters. They are microscopic and single celled.

Diatoms look like two shells that fit together. They are microscopic and single celled.

What are algae?
Algae are photosynthetic creatures. They are neither plant, animal or fungi. Many algae are single celled, however some species are multicellular. Many, but not all of red and brown algae are multicellular. Red and brown algae are common in marine environments. Some green algae are multicellular.

The scum found on ponds are algae. They are the green hairy growth on things found underwater objects. Algae releases oxygen into the water as it manufactures it food. Algae forms the broad base on which the food pyramids in ponds and lakes is built. In manufacturing food, algae release oxygen, increasing the amount dissolved in the water.

However, when algae becomes overabundant the decaying algae depletes oxygen levels. So during the summer, when conditions for growing algae are ripe, oxygen levels may decrease, causing "summerkill" for aquatic plants and animals.

Algae are found in all the fresh waters of the world!

Now do some research in the library.

How many species of algae can you find in each of the major groups?

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