Definition of gill arch in US English:

gill arch


  • 1Any of a series of bony or cartilaginous curved bars along the pharynx, supporting the gills of fish and amphibians.

    • ‘The fifth pair of gill arches is just in front of the pectoral fins.’
    • ‘The buccal cavity is lined with by gill arches, which bear numerous tooth patches.’
    • ‘Inside the fleshy gill arches, used for breathing, lies a system of bony gill arches, which form a finely divided sieve.’
    • ‘It is not extant, but it had gill arches, fins, and several other characters indicative of an aquatic lifestyle.’
    • ‘Originally, it may have been the main upper element of a gill arch.’
    1. 1.1 Any of the corresponding rudimentary structures in the embryos of higher vertebrates.
      • ‘This embryonic origin of the gill arches has been thought to be a good argument for their involvement with the jaw, but against their relationship with the limbs.’
      • ‘They differ from the earlier vertebrates in that some of the gill arches undergo modification in early development to become the jaw and its supporting structures.’
      • ‘Primitively, then, there was a one-to-one correspondence between aortic arches and gill arches.’