The key difference between macroalgae and microalgae is that macroalgae are large and multicellular aquatic photosynthetic plant-like organisms while microalgae are small and unicellular aquatic photosynthetic plant-like organisms.
Algae are large polyphyletic, photosynthetic organisms that contain a diverse group of species. They range from unicellular microalgae such as Chlorella to multicellular macroalgae such as giant kelp and brown algae. They are mostly aquatic and autotrophic in nature. They lack stomata, xylem and phloem, which are found in the land plants.
1. Overview and Key Difference
2. What are Macroalgae
3. What are Microalgae
4. Similarities Between Macroalgae and Microalgae
5. Side by Side Comparison – Macroalgae vs Microalgae in Tabular Form
What are Macroalgae?
Macroalgae are one of the two major types of algae. Macroalgae are large and multicellular. They are commonly referred to as ‘seaweeds’. They are marine organisms resembling big plants in the sea. Macroalgae can be seen without the aid of a microscope.
There are three groups of macroalgae based on their colour. They are red algae, green algae and brown algae. Some macroalgae have a holdfast to attach to sand, boats and rocks. Moreover, they contain thallus, stipes, blades, fronds and air-bladders. Macroalgae are important in biofuel production and as a food or as feedstock.
What are Microalgae?
Microalgae are microscopic small plant-like organisms living in rivers, sea, ponds and lakes. Therefore, we need a microscope to observe microalgae. They are mainly unicellular organisms and some form colonies by grouping many cells together. Similar to plants, they are photosynthetic organisms having photosynthetic pigments and accessory pigments. They can be seen in blue-green, yellow, brown or orange in colour. They are commonly referred to as phytoplankton.
The two main groups of microalgae are diatoms and dinoflagellates. Dinoflagellates belong to the phylum Pyrrhophyta. They are marine, single-celled, eukaryotic algae which have a biflagellated structure. Meanwhile, diatoms, also called as Bacillariophyta, are single-celled, eukaryotic algae that have different shapes and a characteristic theca which is an external cell wall covering the cell. Microalgae cause algal blooms causing the water pollution. However, some microalgae provide foods for aquatic animals.
What are the Similarities Between Macroalgae and Microalgae?
- Macroalgae and microalgae are the two major types of algae.
- They are photosynthetic organisms.
- They have photosynthetic pigments as well as accessory pigments.
- Both microalgae and macroalgae are potential sources of biofuel production.
- Moreover, they have nutritional value as well.
- Besides, they are also used in different environmental applications such as CO2 mitigation, wastewater treatment, biofertilizer production, pigment production, etc.
What is the Difference Between Macroalgae and Microalgae?
Macroalgae are large aquatic photosynthetic plant-like organisms that are visible to our naked eye. They are commonly referred to as seaweeds. Meanwhile, microalgae are small aquatic photosynthetic plant-like organisms that are visible only under the microscope. These are commonly referred to as phytoplankton. Thus, this is the key difference between macroalgae and microalgae. Besides that, another important difference between macroalgae and microalgae is that the macroalgae are multicellular, but microalgae are unicellular.
Below infographic summarizes the difference between macroalgae and microalgae.
Summary – Macroalgae vs Microalgae
There are two main types of algae as macroalgae and microalgae. Macroalgae are commonly known as seaweeds while microalgae are commonly known as phytoplankton. Macroalgae are large and multicellular aquatic photosynthetic plant-like organisms. Hence, they are visible to our naked eye. In contrast, microalgae are small and unicellular aquatic photosynthetic plant-like organisms. Therefore, they are visible only under the microscope. So, this is the key difference between macroalgae and microalgae. Nevertheless, both macroalgae and microalgae produce oxygen and contribute to food production in aquatic environments.
1. “Seaweed.” Wikipedia, Wikimedia Foundation, 3 Mar. 2020, Available here.
2. Mostafa, Soha S.M. “Microalgal Biotechnology: Prospects and Applications.” IntechOpen, IntechOpen, 17 Sept. 2012, Available here.