Question

Which one of the following is not a bioindicator of water pollution?

• A. Sludge-worms
• B. Blood-worms
• C. Stone flies
• D. Sewage fungus

Answer 1

The correct option is C Stone flies

Any organism which indicates the level of pollution in water is called as bioindicator.

Sludge worms, blood-worms, and sewage fungus are indicators of water pollution. As sludge-worms and blood-worms can survive in water with less oxygen and indicates the presence of organic matter in the water body like sewage fungus.

Stoneflies are found worldwide in running water and cannot survive in polluted water so, their presence indicates the good quality of water.