Question

Which one of the following is the oldest use of earthworm?
A. Bait for catching fish
B. Source of manure
C. Food of poultry
D. Medicine for gout

Answer 1

Hint:- Earthworms are included in the phylum Annelida of the animal kingdom. The animals of this phylum are mostly free-living, found in moist soil, freshwater or in marine water and few are also parasitic.
Their body is soft, elongated and cylindrical. It is divided into segments or ring-like structures called annuli. They also have a moist and elastic layer called cuticle on their body surface along with lateral appendages for locomotion.

Complete answer:- Earthworms are included in the class Oligochaeta of the phylum Annelida. These are mostly terrestrial but some are aquatic in nature.
Earthworms are referred to as the farmer's friend because they help in the breakdown of complex organic matter as well as the loosening of the soil.
Earthworms also break down the organics material into smaller particles by the process called fragmentation. Thus they help in the process of decomposition.
As these are found in aquatic environments, these are commonly used as a food material to attract the aquatic animals. They attract the fishes by releasing a particular kind of odour thus used as a bait.
Respiration in earthworms takes place through their moist skin, this is called cuticular respiration. Thus they are found in moist and aquatic environments.
The life cycle of earthworms do not include larval stages thus their development is indirect.

Earthworms are used as a bait in the game called fishing. Thus the correct answer is option A.

Note:- Earthworms have specialised locomotory structures called setae. These are situated in their body wall. They are bisexual or hermaphrodite animals and undergoes external and cross-fertilisation.
Their major role is to make the soil porous by burrowing into it. This helps in respiration and penetration of developing plant roots.