The following points highlight the five modes of locomotion in Protists. The modes are: 1. Pseudopodial Locomotion 2. Flagellar Locomotion 3. Ciliary Locomotion 4. Wriggling Locomotion 5. Locomotion by Mucilage Propulsion.
Mode # 1. Pseudopodial Locomotion:
It is slow creeping type of locomotion which is performed with the help of protoplasmic outgrowths called pseudopodia. Pseudopodial locomotion occurs in sarcodines and slime moulds.
Pseudopodia are of four types:
These pseudopodia are lobe- like with broad and blunt ends. These are present in Amoeba,
These pseudopodia are fine, thread-like, tapering, and are composed of ectoplasm. These are found in Euglypha.
These are long and stiff, with hard axial filament. These pseudopodia are present in Actinophrys.
These are long and branching. The branches of adjacent pseudopodia may form network. These are found in Globigerina.
Mode # 2. Flagellar Locomotion:
Flagella show whip-like movement. They usually beat independently. This type of locomotion occurs in dinoflagellates (e.g., Gonyaulax), euglenoids (e.g., Euglena) and zoo-flagellates (e.g., Leishmania).
Mode # 3. Ciliary Locomotion:
Cilia show oar-like movement. All the cilia of a cell show coordinated movements which are of two types, isochronic and metachronic rhythms. In isochronic or synchronous rhythm, all the cilia of a cell beat simultaneously. They do so in rapid succession one after the other in case of metachronic rhythm. It occurs in ciliates (e.g., Paramecium).
Basically flagella and cilia are identical in structure. However, they differ in some respects as mentioned below.
Mode # 4. Wriggling Locomotion:
It is slow worm-like movement which is performed with the help of a wave of contraction and expansion in the body, e.g., sporozoans, no flagellates, euglenoids.
Mode # 5. Locomotion by Mucilage Propulsion:
Some protists like diatoms do not have any organelles of locomotion. They can, however, move from one place to another through secretion of mucilage. This type of locomotion occurs in the direction opposite to that of mucilage secretion.