Chlorophyceae green Algae

Green Algae

1. Chlorophyceae Green Algae हरा शैवाल

2. This group contains 425 Genera & 6500 species but later Prescott(1969) reported over 20,000 species. (continuously discovering). It contains Chlorophyll A & B dominates over Cartenoids & Xanthophyll which gives green colour . About 90% are freshwater & rest are saline& terrestial .Some freshwater forms are: Volvox , Odeogonium , Spirogyra . Some marine green algae are : Sea lettuce( ulva ), Turtle grass( Chlorodesmis ).

3. A wide range of variation is seen in their thallus : unicellular ( motile ) - Chlamydomonas & non-motile ( Volvox,Chlorella ) Filamentous branched ( Cladophora ) unbranched ( Spirogyra ). Inner Cell wall is of cellulose & outer is of pectose . The flagellate cells have eye-spot or stigma in the anterior portion .(remain inserted on a side of chloroplast )

4. Pigments are located in chloroplast & they may be cup shaped, discoid, c-shaped , reticulate etc. In some members one more storage body present in chloroplat i.e Pyrenoids ( proteins beside starch ). Phycobillins are absent .

5. Reserve food is starch, composed of amylose and amylopectin & also in form of oil droplets . Reproduce by all the three means: vegetative, asexual & sexual Vegetative by - fragmentation(spirogyra) & by - cell division( pleurococcus ) Asexually by flagellated zoospores & aplanospores . Sexually by isogamous , anisogamous & oogamous .

6. Importance of green algae Used as food source by animals & human beings. Vitamins & minerals are obtained from these. Carotene is used for food coloring & also effective against cancer. Chlorella is source of food for astronauts .

7.   Codium fragile Marimo Water silk Chara