Opisthobranchia

plural noun

Opis·​tho·​bran·​chia

zoology

: a large order of Euthyneura comprising marine gastropod mollusks having the gills when present posterior to the heart and having no operculum compare streptoneura see nudibranchia, tectibranchia

opisthobranchiate

⸗¦⸗⸗¦braŋkēə̇t

-ēˌāt

adjective or noun

Word History

Etymology

New Latin, from opisth- + -branchia

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