The remainder of the primitive alimentary sack gives rise to the branchial sack of the adult.
The branchial cavity can dilate and contract itself alternately.
Indications of a branchial lobe (gill) are seen in two specimens where the legs are not preserved.
Originally they are mainly concerned with branchial respiration.
In the Cumacea and Tanaidacea only the first thoracic limb has a branchial epipodite.
The remains of only two branchial arches are found in the adult.
A more probable view is that it develops from rests derived from the first branchial arch an not from the parotid.
At such times the gills lose all semblance of branchial organs.
There is a single row of these on the first and fourth branchial arches, and two rows on the second and third.
They are termed the “branchial clefts,” and are seen in the embryos of all vertebrates.
branchial bran·chi·al (brāng'kē-əl)
Of, relating to, or resembling the gills of a fish, their homologous embryonic structures, or the derivatives of their homologous parts in higher animals.