Definition of gill arch in English:
1Any of a series of bony or cartilaginous curved bars along the pharynx, supporting the gills of fish and amphibians.
- Originally, it may have been the main upper element of a gill arch.
- 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.
1.1Any of the corresponding rudimentary structures in the embryos of higher vertebrates.
- 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.
- 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.
- Primitively, then, there was a one-to-one correspondence between aortic arches and gill arches.