Before we dive into the classification of algae, let’s first have a look at what they are. The algae are a diverse group of aquatic photosynthetic organisms. Now, like plants, algae have chlorophyll in them and they prepare their food via photosynthesis, they do not have any roots or leaves as the plants do. They also exist in a wide range of sizes; from microscopic to tens of meters in length. Apart from this, many of them are unicellular while others are multicellular.
The study of algae is known as phycology and those who study it are called phycologists.
Let’s now look at the classification of algae. They are classified into three categories:- Chlorophyceae, Phaeophyceae, and Rhodophyceae.
Classification of Algae
| Features | Chlorophyceae | Phaeophyceae | Rhodophyceae |
| Common Name | Green Algae | Brown Algae | Red Algae |
| Photosynthetic Pigment | Chlorophyll A and B | Chlorophyll A, C, and Fucoxanthin | Chlorophyll A, B, and Phycoerythrin |
| Stored Food | Starch | Mannitol and Laminarin | Floridean Starch |
| No. of Flagella and their Position | Typically 2 with equal and lateral insertion | Typically 2, with unequal and lateral insertion | Absent |
| Cell Wall Composition | Composed of Cellulose | Composed of cellulose and algin | Composed of cellulose and algin |
In short, the classification of algae is based on the type of photosynthetic pigment they contain, the type food they store, number & position of flagella and their cell wall composition.
