Waterway Cleaners

Catfish play an important role in keeping many freshwater ecosystems functioning smoothly. This passage explains how they feed on insects, small fish, plant matter, and organic material that settles to the bottom, helping recycle nutrients and prevent too much waste from building up. Readers also learn that catfish are an important food source for birds, larger fish, and other predators, which makes them a key part of aquatic food webs. The passage helps students see that even bottom-dwelling fish can have a major influence on the health of rivers, lakes, and ponds.

This worksheet gives students practice identifying main ideas, tracing food-chain relationships, and understanding how one species can affect an entire ecosystem. Vocabulary such as nutrients, food web, organic matter, predator, and ecosystem builds science understanding through clear examples. Students also strengthen cause-and-effect thinking by connecting catfish feeding habits with cleaner water and healthier habitats. It’s a good passage for helping children see that every organism has a role, even if that role isn’t always obvious.