Life Cycle, Regeneration and Economic Importance

Fertilization and the earliest development of Lampito mauritii both occur inside the protective cocoon secreted by the clitellum; the cocoon is deposited in the soil and hatches after an incubation period of roughly 14-18 days, releasing a juvenile worm directly - there is no free-living larval stage. The juvenile passes through a non-clitellate growth phase (about 15 days) and then a second growth phase (about 15-17 days) during which the clitellum develops, becoming a clitellate, sexually mature adult; after mating and cocoon deposition roughly 10 days later, the whole life cycle, from cocoon to cocoon, takes about 60 days. Earthworms also have a limited capacity for regeneration: because the animal's most important organs are concentrated in its first 20 segments, a worm cut behind segment 20 can regrow its anterior half, while the disconnected posterior half eventually disintegrates. Economically, earthworms are prized for making soil porous (helping both aeration and root penetration) and for recycling dead organic matter, and …