Question

Pheretima posthuma is highly useful as

• A. their burrows make the soil loose
• B. they make the soil porous, leave their castings and take organic debris in the soil
• C. they are used as fish meal
• D. they kill the birds due to biomagnification of chlorinated hydrocarbons.

Answer 1

Answer: (B)

they make the soil porous, leave their castings and take organic debris in the soil

Answer 2

Pheretima posthuma is highly useful and beneficial in agriculture. Its habit of burrowing and swallowing earth makes it porous and increases the soil fertility in many ways. Their burrows permit penetration of air and moisture in porous soil and their excretory wastes and other secretions also enrich soil by adding nitrogenous matters to the soil. Pheretima posthuma is not used as fish meal. Whereas a small white earthworm (Enchytraeus alhidus) is often grown in soil and used to feed aquarium fish.