Aquatic organisms that move actively use appendages like fins which are modified for swimming. Many plankton which drift in the water have devices for keeping them afloat such as oil droplets and ciliated bands.
Animals are actively moving terrestrial organisms. They have
• jointed limbs (arthropods) , and
• pentadactyl limbs (vertebrates)
That are specially adapted for running, jumping, crawling, climbing and digging. In birds, the pentadactyl upper limbs have been structurally adapted into wings for flying.
