what is a sea slug characteristics
Characteristics: In all sea slugs (formerly known as Opisthobranchia) you will find the gills behind the heart. The sea slugs originate from the sea snails which have the gills in front of the heart. The shell is usually internal or completely lost at some point during evolution.The name Heterobranchia means different-gilled snails.he sea slugs originate from the sea snails which have the gills in front of the heart. The shell is usually internal or completely lost at some point during evolution. The name Heterobranchia means different-gilled snails.