Examples of filter feeders include flamingos, basking sharks, whale sharks and baleen whales. Other filter feeders are sponges and pelagic tunicates. Branchiopods such as water fleas and brine shrimp also employ filter feeding. These animals have a type of straining system that helps filter the tiniest animals or plants from the water.
Flamingos usually feed by wading in shallow water. They use their feet to stir up mud from the bottom, and then dip their heads upside down in the water. They open their bill slightly and sweep their heads from side to side. This pumps water in and out of their bills, which are lined with plates called lamellae. Food is sieved through the lamellae into the birds' mouths.
The basking and whale sharks are the largest fish in the sea, but they use their gills to filter out tiny plankton. They often swim with their mouths open and simply suck in everything in their path. The enormous mouths of baleen whales have plates filled with coarse, hair-like bristles to help them filter feed. These whales include the humpback whale and the right whale.
Sponges, most of which hardly move at all as adults, also passively filter food from the water. The same is true for tunicates like sea squirts.