Question: what is the difference between a sea slug and a nudibranch?
Answer: Often the term “nudibranch” is used for all sea slugs. However, while all nudibranchs are sea slugs, not all sea slugs are nudibranchs. ... So in other words “sea slug” does not say anything about the relations between the different species but it is a common name for snails or slugs that live in the ocean.