prosobranch

Encyclopedia

prosobranch

any snail of the subclass Prosobranchia, class Gastropoda. Most of these primitive snails are marine; a few live on land or in fresh water. Many prosobranchs breathe by means of gills, which are located in front of the heart; some have a special respiratory structure on the mantle or, in land species, a simple pulmonary cavity. The auricle of the heart is in front of the ventricle. Larval torsion results in a figure-eight arrangement of the viscera and nerve cord that persists throughout life. Most species have a lid (operculum) on the foot that closes the shell when the animal retracts. The sexes are separate

Learn more about prosobranch with a free trial on Britannica.com.

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
Cite This Source
Explore Dictionary.com
Previous Definition: proslaveryism
Next Definition: prosobranchiata
Words Near: prosobranch
More from Thesaurus.com
Synonyms and Antonyms for prosobranch
More from Reference.com
Search for articles containing prosobranch
More from Dictionary.com Translator
Dictionary.com Word FAQs

Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.

Related Searches
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature
FAVORITES
RECENT

;