Definition of amphioxus in US English:



  • A lancelet that is caught for food in parts of Asia.

    Genus Branchiostoma (formerly Amphioxus), family Branchiostomidae

    • ‘Thus amphioxus is the only chordate species in which distinct insulin and IGF genes have not been found.’
    • ‘For this interesting animal, extensive morphological and developmental biological studies have been conducted, but limited information has been available on endocrinology and physiology of amphioxus.’
    • ‘A few years ago, some molecular embryology data on amphioxus have revived the long forgotten hypothesis that the ancestor of coelomates was a segmented animal.’
    • ‘Organisms along the lines of the cephalochordate amphioxus use the gill apparatus for filter feeding.’
    • ‘The cephalochordate amphioxus is the closest living invertebrate relative of the vertebrates and therefore the best model organism for understanding the composition of the ancestral chordate genome.’


Mid 19th century: modern Latin, from amphi- + Greek oxus ‘sharp’.