Branchial arches or gill arches are a series of paired bony/cartilaginous "loops" behind the throat of fish, which support the fish gills. As chordates, all vertebrate embryos develop pharyngeal arche

Agnatha or jawless fish is a paraphyletic infraphylum of animals in the subphylum Vertebrata of the phylum Chordata, characterized by the lack of jaws. The group consists of both living and extinct cl