Q. Which one of the following is not a bioindicator of water pollution?
A) blood-worms
B) stone flies
C) sewage fungus
D) sludge-worms
Explanation
[Solution from source] Blood-worms (Chironomus larvae), sludge-worms (Tubifex) and sewage fungus thrive in organically polluted, low-oxygen water and so indicate pollution. Stonefly nymphs need clean, well-oxygenated water and disappear when water is polluted, so they indicate clean water instead. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.