Filter feeders (also known as suspension feeders) are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized structure, such as the baleen of baleen whales.

Filter feeding is one of the four major types of feeding. Some animals that use this method of feeding are clams, krill, flamingos, and sponges.

Slow motion movie (300 frames per second) of Antarctic krill pump filtering with the feeding basket formed by the six thoracopods shown by krill whiile collecting phytoplankton from the open water. The krill is hovering at a 55 degree angle at the spot. This behavior is shown under very high phytoplankton concentrations. In lower food concentrations the feeding basket is pushed through the water over half a meter in an opened position.

Ultrastructure of the krill filter: The first degree filter setae carry in v-form two rows of second degree setae, pointing towards the inside of the feeding basket (electron microscope image). To display the total area of this fascinating structure one would have to tile 7500 times this image.

Contrast with:

• Deposit feeders
• Fluid feeders
• Food-mass feeders