Annelids, segmented or ringed worms, are present both in soil and sea. There are more than 9000 species of annelids. They are important economically and ecologically for many reasons.
Annelids present in soil mainly come under two categories; burrowers and those live on surface. The burrowers loosen the soil making penetration of water and oxygen easy. Thus annelids keep soil aerated and fertile. Both accelerate the process of decomposition of organic matter and minerals. This makes consumption easy for other organisms and plants. They also support production of soil by mixing minerals and organic matter. Hence, annelids play a supportive role in agricultural production.
An earthworm, the most common annelid, is food for many birds, rodents, mammals, aquarium fish and laboratory animals. Presence and conservation of earthworms has become essential for conservation some species of endangered birds. Earthworm is excellent fishing bait.
Certain varieties of annelids like, the epitokes of Eunice (Palolo worms) are used as food by the native people. They are highly nutritive. Annelids have importance in treatments. The medicinal leech was used by doctors to bleed their patients. Though this practice is not being followed now, medicinal leech is still used to heal severed appendages. They are also used in cosmetic surgeries and skin grafts because of their anesthetics and antibiotics powers. Some earthworms are used in interior parts of China, India and Japan for preparing medicines for bladder stones, jaundice, piles and rheumatism.
Earthworms and leeches are widely used for dissection and for studying comparative physiology in colleges and universities.
Burrowing species of marine annelids supports the penetration of water and oxygen into the sea-floor sediment. These sediments support the life of aerobic bacteria and small animals alongside their burrows. Marine annelids are food for plants and animals living in sea. What are annelids? What are examples of annelids?