explain Phylum Annelida
Answers
Answer:
- phylum annelida refers to the worms it consists of ringed worms or segmented worms .
★ PHYLUM - ANNELIDA:-
→ Their body surface is distinctly marked out into segments or metameres and hence, the phylum name Annelida.
→ Habitat - aquatic (marine and fresh water) or terrestrial; free-living, and sometimes parasitic.
→ Level of organization - organ-system level and triploblastic animals.
→ Symmetry - bilateral symmetry.
→ Body cavity - present and coelomates.
→ Locomotory organ - Body wall which has longitudinal and circular muscles.
→ Circulatory system - closed circulatory system.
→ Excretory organ - Nephridia which help in osmoregulation and excretion.
→ Nervous system - consists of paired ganglia connected by lateral nerves to a double ventral nerve cord.
→ Reproduction - some are unisexual or dioecious and some are bisexual or monoecious. Reproduces sexually.
→ Examples:- Nereis, Pheretima and Hirudinaria