Question

Which is not a bioindicator of water pollution?
A. Blood worms
B. Stoneflies
C. Sewage fungus
D. Sludge worms
E. None of the above

Answer 1

The organisms that belong to a group of polychaetes are usually found in marine water but acts as an endoparasite in the human body. They live in the tissues and organs of the body.

Complete answer: Stone flies belong to the order Plectopora of the insects. They are found worldwide and act as biological indicators of water quality. They are aquatic but their adult form also lives on land. They lay eggs in the water and larvae hatch in the water. Their larvae are very sensitive to water pollution and they need a high quantity of dissolved oxygen. When the temperature rises, they start dying. Therefore, they act as bioindicators of water pollution. The overgrowth of sewage fungus and sludge worms indicate that the water body is highly polluted. The blood worms are not bioindicators of water pollution because they are endoparasites of humans. They belong to genus Glycera. They are polychaetes and are found on the shallow bottom of the marine waters. They are creamy pink in colour and have small fleshy projections known as parapodia and also contain antennae.
Hence, the correct answer is option A.

Note: Bioindicator organisms are utilized to screen the natural ecosystem of the environment. Several organisms can act as bioindicators of water pollution such as algae, fungi, flies, worms, lichens, etc. Lichens and bryophytes serve as effective bioindicators of air quality because they have no roots, no cuticle, and acquire all their nutrients from direct exposure to the atmosphere.