The key difference between chrysophytes and euglenoids is that chrysophytes are a group of Protista that involves diatoms and desmids, while euglenoids are a group of Protista that involves single-celled algae which do not possess a cellulosic cell wall.
Kingdom Protista includes unicellular eukaryotic organisms. Most of the protists are photosynthetic. They show both plant-like and animal-like features. Many species are aquatic organisms, and they are the main producers of aquatic environments. They have cilia or flagella. Slime moulds, protozoa, euglenoids, dinoflagellates and chrysophytes are the major five sub-groups of kingdom Protista. Chrysophytes include diatoms and golden algae. They produce a unique carbohydrate called chrysolaminarin. Euglenoids include mostly freshwater algae. They lack a cellulosic cell wall, but they possess a pellicle and eyespot.
CONTENTS
1. Overview and Key Difference
2. What are Chrysophytes
3. What are Euglenoids
4. Similarities Between Chrysophytes and Euglenoids
5. Side by Side Comparison – Chrysophytes vs Euglenoids in Tabular Form
6. Summary
What are Chrysophytes?
Chrysophytes is a major group belonging to the kingdom Protista. It includes diatoms and desmids. Desmids are also known as golden algae. Chrysophytes are classified into approximately one hundred genera with over 1000 described chrysophytes species. They are mostly photosynthetic organisms found in both fresh water and marine water.
Figure 01: Diatoms
Diatoms are the chief producers in aquatic environments. They have unique double shells made of silica. Hence, they appear as small boxes with lids. Some examples of diatoms are Cymbella, Navicula and Melosira. They are unicellular eukaryotic organisms. They are microscopic and float passively in water currents. Chrysophytes produce a unique carbohydrate called chrysolaminarin. They have cell walls made of cellulose strengthened by silica compounds. But, amoeboid forms chrysophytes do not have a cell wall.
What are Euglenoids?
Euglenoids are single-cell flagellated organisms of kingdom Protista. They are a large group of algae. There are about 54 genera and 900 species in this group. They live in freshwater, stagnant water and also in marine water. But they are commonly found in freshwater, which is rich in organic materials. Euglena and Phacus are two representative genera of euglenoids. Most euglenoids are unicellular except the colonial genus Colacium. Many euglenoids are spindle-shaped. Many of them have chloroplasts, so they are photosynthetic. Others feed by phagocytosis or by diffusion.
Figure 02: Euglenoid
Furthermore, they have two flagella; one is long and functional while the other is short and does not protrude. Euglenoids do not have a cell wall. They have a protein-rich cell covering called pellicle, which provides flexibility to euglenoids. Moreover, euglenoids have an eyespot that acts as a light-sensing device. They also have a contractile vacuole. It helps euglenoids to pump out excess water from their bodies. Furthermore, some euglenoids are capable of producing resting spores which are useful under unfavourable environmental conditions.
What are the Similarities Between Chrysophytes and Euglenoids?
- Chrysophytes and euglenoids are two of the five subgroups of kingdom Protista.
- They are unicellular eukaryotic organisms.
- Both are aquatic organisms.
- They are mostly photosynthetic; hence they appear as plant-like protists.
- They are flagellates.
- Both are algae.
What is the Difference Between Chrysophytes and Euglenoids?
Chrysophytes are plant-like protists found in marine and freshwater environments, while euglenoids are a subgroup of Protista that includes single-celled algae with a pellicle and eyespot. So, this is the key difference between chrysophytes and euglenoids. Moreover, chrysophytes have cell walls made of cellulose, strengthened by silica compounds, while euglenoids do not have a cellulosic cell wall. Also, chrysophytes have pigments such as chlorophylls a and c, fucoxanthin and xanthophylls, while euglenoids have chlorophylls a and b, and carotenoids.
The below infographic lists the main differences between chrysophytes and euglenoids in tabular form.
Summary – Chrysophytes vs Euglenoids
Chrysophytes and euglenoids are two groups of Protista. They are unicellular, aquatic and mostly photosynthetic eukaryotic organisms. Chrysophytes are plant-like, while euglenoids show both plant-like and animal-like features. Chrysophytes are two types as diatoms and desmids. Chrysophytes have a cell wall, while euglenoids do not have a cell wall composed of cellulose. Euglenoids have an eyespot and pellicle, unlike chrysophytes. Thus, this summarizes the difference between chrysophytes and euglenoids.
Reference:
1. “Kingdom Protista.” BIOLOGY4ISC, Available here.
2. “Biological Classification.” EMedicalPrep, Available here.
Image Courtesy:
1. “Diatoms Under A Microscope Slide Drawing” (CC0) via Pixy
2. “Euglenoid movement” By Rogelio Moreno – Rogelio Moreno (CC0) via Commons Wikimedia