Pattern of gill innervation in two teleosts, the perch and the trout

The distribution of the branchial nerves in the gills of the perch (Perca fluviatilis) and the rainbow trout (Oncorhynchus mykiss) was studied. Two nerve branches supply each gill arch: the first arch receives a posttrematic branch from the glossopharyngeal nerve and a pretrematic branch from the vagus. The second, third, and fourth arches receive a posttrematic and a pretrematic branch from the vagus. Within each arch the posttrematic branch …