Cryptophytes, Euglenophytes
Cryptophytes are often abundant in the plankton both from the lakes and the sea, mostly from fresh water. They are an important source of food to small invertebrates. They all are unicellular and the colour is yellow, red or brown. Chryptophytes are without cell wall, and the cell form is variable and the cells are therefore difficult to identify. The cell has two flagella of slightly uneven length. An in agination extends down from near the apex of the cell.
The image (to the left) shows Rhodomonas with red colour. Rhodomonas is very common in fresh water. The cell size is about 10 my.
Cryptomonas with the brown colour are also common in lakes. The size is about 40-60 my