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A genus of small, translucent, fishlike chordates found in warm marine waters. Members are structurally similar to vertebrates in having a notochord, gills, digestive tract, and nerve cord, but they lack paired fins, vertebrae, ribs, or a skull for example, Branchiostoma lanceolatum.
[amphi- + G. oxys, sharp]
Farlex Partner Medical Dictionary © Farlex 2012


See lancelet.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


the disused scientific, though better-known, name for Branchiostoma (the lancet), a PROTOCHORDATE found in many parts of the world. Its embryonic development has been extensively studied and is used in texts as an example of a link between invertebrates and vertebrates. It feeds by ciliary action, trapping food particles in mucus.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
The debut screening of "Amphioxus" provoked a lively discussion in its German-speaking audience.
The research  appeared in the journal PLOS ONE under the title "Molecular regionalization of the developing amphioxus neural tube challenges major partitions of the vertebrate brain."
The recombinant protein of amphioxus GHl (rGHl) was prepared as described by Li et al.
"Amphioxus can therefore be regarded as a 'very distant cousin' to all the vertebrate (backboned) species," she said.
(62.) A cartilaginous rod found in vertegbrate embryos, running between the primitive vertebrates such as the lancelet or Amphioxus.
(2007) reported nine Pax genes in amphioxus, also lacking eyes, including four newly described homologues of six and eyes absent.
Instead, they resemble the living invertebrate called amphioxus, a passive filter-feeding marine animal.
Among the chordates, Branchiostoma, the lancet or amphioxus, has a single skeletal element, the notochord.
Identification and expression of a novel class of glutathione-S-transferase from amphioxus Branchiostoma belcheri with implications to the origin of vertebrate liver.
However, in recent years a number of examples have emerged in which animal eyes appear to develop without the expression of a Pax-6 ortholog, including the adult eyes of the annelid worms in the genus Platynereis (Arendt et al., 2002) and some of the photoreceptor subtypes of amphioxus (Glardon et al., 1998).