Question

What are the features of phylum Annelida

Answer 1

Answer:

The annelids, also known as the ringed worms or segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments.

Answer 2

Features of Annelida-

1. They may be aquatic or terrestrial or free living or parasitic.
2. They have organ system level of body organisation.
3. They have long body.
4. They have brain.
5. Have true coelom.
6. Digestive system is complete.
7. They are triploblastic.
8. They are metamerically segmented.
9. They have longitudal and circular muscles which help them in locomotion.
10. They have closed circulatory system.
11. Blood is red.
12. Have nervous system.
13. Nephrida helps in osmoregulartion.
14. Nephrida also helps in excretion.
15. They are bilaterally symmetrical.

Example- Earthworm, Nereis etc

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1. The class Polychaeta includes marine forms.
2. They have distinct head and parapodia.
3. ex- nereis

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1. The oligochaeta class includes fresh water or burrowing forms.
2. locomotary structures are setae and are fewer in number.
3. Ex- Earthworm.

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1. The Hirudinaria class includes animals with elongated and convex dorsal surface.
2. Body surface always remain moist.
3. Ex- Leech