Filter feeding

Definition

Filter feeding is a feeding mechanism used by various aquatic organisms to obtain nutrients by straining suspended particles, including plankton and organic matter, from the water. This process involves drawing water through specialized structures that trap food particles while allowing excess water to flow out, playing a critical role in the nutrient cycling within aquatic ecosystems.

5 Must Know Facts For Your Next Test

1. Filter feeding is predominantly seen in organisms like sponges and certain cnidarians, which use it as their primary means of obtaining food.
2. In sponges, the process of filter feeding is facilitated by choanocytes that create a water current, allowing for efficient particle capture.
3. Cnidarians like sea anemones can also filter feed by using their tentacles to capture small food particles while simultaneously engaging in predation.
4. Filter feeders help maintain water clarity and quality by removing excess nutrients and particles, thereby playing an important role in aquatic ecosystems.
5. Many filter feeders are vital to nutrient cycling, as they convert suspended organic materials into biomass that can be consumed by higher trophic levels.

Review Questions

• How do sponges utilize filter feeding to obtain nutrients from their environment?
  • Sponges employ filter feeding by utilizing specialized cells called choanocytes, which have flagella that create a water current. As water flows through the sponge's porous body, these cells trap food particles such as bacteria and plankton. The trapped food is then ingested by the choanocytes or passed on to other cells within the sponge for digestion, making filter feeding essential for their survival in aquatic environments.
• Compare and contrast the mechanisms of filter feeding in sponges and certain cnidarians.
  • Both sponges and certain cnidarians utilize filter feeding as a way to capture nutrients from the water, but they do so through different mechanisms. Sponges rely on choanocytes to create a continuous flow of water through their bodies, trapping food particles in the process. In contrast, cnidarians such as sea anemones use their tentacles lined with cnidocytes to capture prey and filter out small particles from the water. While both organisms benefit from this feeding method, their anatomical structures and approaches differ significantly.
• Evaluate the ecological significance of filter feeders in maintaining aquatic ecosystem health and stability.
  • Filter feeders play a crucial role in maintaining aquatic ecosystem health by regulating nutrient levels and improving water quality. They remove excess nutrients and suspended particles from the water column, which helps prevent issues like algal blooms that can harm aquatic life. By converting suspended organic matter into biomass, filter feeders also support higher trophic levels, contributing to biodiversity and ecosystem stability. Their activity promotes nutrient cycling, making them integral to the overall functioning of aquatic habitats.

Related terms

Choanocyte: A type of cell found in sponges that has a flagellum surrounded by a collar of microvilli, which helps in the filtration of water and trapping of food particles.

Plankton: Tiny organisms, both phytoplankton (plant-like) and zooplankton (animal-like), that float in the water column and serve as essential food sources for many filter feeders.

Cnidocytes: Specialized cells found in cnidarians that contain stinging structures called nematocysts, used for capturing prey and defense, but also play a role in filtering small particles from the water.