opisthobranch

[ uh-pis-thuh-brangk ]

noun

1. any gastropod mollusk of the order Opisthobranchia, as the sea slugs, sea butterflies, and sea hares, characterized by a vestigial or absent mantle and shell and two pairs of tentacles.

adjective

1. of or relating to the opisthobranches.

opisthobranch

/ əˈpɪsθəˌbræŋk /

noun

1. any marine gastropod of the class Opisthobranchia (or Opisthobranchiata ), in which the shell is reduced or absent: includes the pteropods, sea hares, and nudibranchs

Word History and Origins

Origin of opisthobranch¹

1850–55; < New Latin Opisthobranchia the subclass; opistho-, branchia

Word History and Origins

Origin of opisthobranch¹

via New Latin from Greek opisthen behind + -branch