Which one of the following is a filter feeder?
- Catfish
- Octopus
- Oyster
- Pelican
Explanation
Option (c) is correct
- Filter feeders are organisms that feed by straining suspended matter and food particles from water. They play a crucial role in aquatic ecosystems by helping to maintain water quality and nutrient cycling.
- Oysters are classic examples of filter feeders. They feed by drawing water in through their gills, filtering out plankton, algae, and other small particles, which they then consume. This process not only nourishes the oyster but also plays a significant environmental role by filtering and cleaning the water. Oysters can filter large volumes of water daily, significantly improving water quality in their habitats. Their feeding method involves trapping particles in mucus and transporting them to the mouth, where they are ingested. This feeding strategy allows oysters to thrive in nutrient-rich waters, contributing to the stability of marine ecosystems. As efficient filter-feeders, oysters remove nitrogen and incorporate it into their shells and tissue. Near oyster reefs, the water is often clearer.
Option (a) is incorrect
- Catfish are not filter feeders; they are bottom feeders that consume a wide variety of food, including small fish, insects, and plant material. They use their barbels (whisker-like organs) to detect food on the riverbed or lake floor.
Option (b) is incorrect
- Octopuses are carnivorous predators that primarily feed on crabs, shrimp, fish, and other small marine creatures.
Option (d) is correct
- Pelicans are large water birds known for their distinctive pouch-like beak, which they use to catch fish. While they scoop up fish along with water, they do not filter feed. Instead, they drain the water from their pouch and swallow the prey.
