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 origin
via New Latin from Greek opisthen behind + -branch
Examples of 'opisthobranch' in a sentence
opisthobranch
Opisthobranch molluscs exhibit fascinating body plans associated with the evolution of shell loss in multiple lineages.
Zer Vue, Bishoy S. Kamel, Thomas R. Capo, Ana T. Bardales, Mónica Medina 2014, 'Comparative analysis of early ontogeny in Bursatella leachii and Aplysia californica',PeerJhttps://peerj.com/articles/700.pdf. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)