conchology
Scientific term for the study of mollusk shells. Used in academic and collector contexts.
He is a conchology expert and collects shells from around the world.
I took a conchology course at university.
軟体動物学 is malacology, the study of mollusks as a whole, including soft body parts, whereas 貝類学 often emphasizes shells.
Compound of 貝類 (shellfish, mollusks) + 学 (study, -ology). The term is a straightforward modern academic coinage.