The aquatic animals of this phylum possess parapodia for locomotion.

Botryoidal tissue is found in

Which class of animals possesses a closed circulatory system?

Given below are two statements. One is labelled as Assertion $(A)$ and other is labelled as its Reason $(R)$.
Assertion $(A) :$ In $Nereis$,longitudinal and circular muscles help in locomotion.
Reason $(R) :$ $Nereis$ is an aquatic annelid which is monoecious and possesses lateral appendages called parapodia,which help in swimming.

Animals of this phylum excrete through nephridia.

$Parapodia$ are lateral appendages used for locomotion in which of the following organisms?