snails im pretty sure
It is well known that the clam is by far the most active mollusk
most have shells
?
It is the most complex type of mollusks.
In the seas
Most are in water.
cephalopod
Most mollusks are free-living but there are a few that are parasitic.
The thin folded membranous tissue that envelops most of the visceral mass in mollusks is called the mantle. The mantle is common on all mollusks, including those that live in freshwater.
Open
open!
The comparative adjective form is more active. The superlative adjective form is most active.