Annelids are the organisms having bilateral symmetry. They are triploblastic with tube within the tube body plan. They are metamerically segmented with closed circulatory system.The excretory organ of annelids is Nephridium. Cuticle of annelids is non-chitinous and albuminoid. Annelids have Schizocoelic coelom.
Among annelids great power of regeneration is observed in Chaetopterus. A clam worm possesses 2 pairs of eye. Nereis is gregarious, nocturnal and carnivorous. Eunice is an example of Errantia.
Phylum annelida resembles Mollusca in embryonic features because both have identical conspicous segmentation in body muscles ans nervous system.
The phylum annelida is divided in to 4 classes:
A. Polychaeta
B. Oligochaeta
C. Hirudinea
D. Arachinnelida
No comments:
Post a Comment