Portion of tissue, located on the lower jaw that defines the caudal extent of the labial cavity. The oral valves control the flow of water into the mouth during routine respiration. [ ORCiD:0000-0001-9114-8737 http://zfin.org/ZDB-PUB-060921-12 GOC:mh ]
Synonyms: lower internal lip lower semilunar valve mandibular valve