Biology_of_Earthworm with basic details and labelled diagrams

Earthworms are known as ‘friends of farmers’ because they improve soil fertility and
structure. Their burrowing activities aerate the soil, enhance drainage, and mix organic matter with soil minerals.
They accelerate decomposition and nutrient cycling, benefiting crop productivity. Vermicomposting, a process using
earthworms to convert organic waste into manure, is widely practiced for sustainable agriculture.

1. Biology of Earthworm Detailed Study with Diagrams & Labelled Parts

2. Introduction to Earthworms Earthworms are segmented invertebrates belonging to Phylum Annelida. They are commonly found in moist soil and play a vital role in soil fertility.

3. Classification Phylum: Annelida Class: Oligochaeta Order: Opisthopora Genus: Pheretima / Lumbricus

4. General Morphology Body is elongated, cylindrical, bilaterally symmetrical and segmented. Color: Brownish due to porphyrin pigment.

5. External Features Distinct regions: Prostomium, Peristomium, Segments. Clitellum present (in mature worms).

6. Body Wall & Musculature Consists of cuticle, epidermis, circular and longitudinal muscles.

7. Digestive System Straight alimentary canal with mouth, buccal cavity, pharynx, esophagus, gizzard, intestine, anus.

8. Circulatory System Closed type with blood vessels and hearts. Blood contains hemoglobin dissolved in plasma.

9. Respiration Occurs through moist skin (cutaneous respiration).

10. Nervous System Consists of nerve ring, cerebral ganglia (brain), ventral nerve cord.

11. Excretory System Segmentally arranged nephridia: septal, integumentary and pharyngeal.

12. Reproductive System Hermaphroditic but cross fertilization occurs. Male and female reproductive organs present.

13. Economic Importance • Soil fertility improvement • Vermicomposting • Food for other animals • Used in scientific research.

14. Summary Earthworms are vital soil organisms. Their biology explains their ecological and economic importance.