Notes from NEET topper
Phylum- Annelida
• Body shape-marked out into metameres/ segments(latin-annulus or little ring).
• Habitat-aquatic, terrestrial, free-living, rarely parasite
• Locomotory organs-body wall has longitudinal & circularmuscles. Aquatic annelids likeNeries possess lateralappendages, Parapodia for swimming.
• Circulatory system-closed.
• Excretory system-nephridia help in osmoregulation.
• Nervous system-paired ganglia connected by lateralnerves to a double ventral nerve cord.
• Reproduction- some unisexual(Neries) ,some bisexual(Earthworm, Leech).
• Eg-Nereis, Pheretima (Earthworm),Hirudinaria(blood sucking leech)
