Branchial arch muscle innervation by the glossopharyngeal (IX) and vagal (X) nerves in tetraodontiformes, with special reference to muscle homologies.
Branchial arch muscle innervation by the glossopharyngeal (IX) and vagal (X) nerves in 10 tetraodontiform families and five outgroup taxa was examined, with special reference to muscle homologies. Basic innervation patterns and their variations were described for all muscle elements (except gill filament muscles). In the tetraodontids Takifugu poecilonotus and Canthigaster rivulata, diodontid Diodon holocanthus, and molid Mola mola, levator externus 4 was innervated by the 3rd vagal branchial trunk (BX3) in addition to BX2, owing to strong posterior expansion of the muscle. Based on nerve innervation, migrations of the muscle attachment sites (i.e., origins and insertions) were recognized in levator internus 2 (in Mola mola), obliquus dorsalis 3 (in Ostracion immaculatus and Canthigaster rivulata), and obliquus ventralis 2 (in Stephanolepis cirrhifer), muscle topologies not necessarily being indicative of homologies. Embryonic origin of the retractor dorsalis and parallel attainment of the swimbladder muscle within the order were also discussed.
Nakae
Masanori
M
Laboratory of Marine Biology, Faculty of Science, Kochi University, 2-5-1 Akebono-cho, Kochi 780-8520, Japan.
Sasaki
Kunio
K
D000818:Animals; D001934:Branchial Region / Q000033:anatomy & histology*; D005930:Glossopharyngeal Nerve / Q000033:anatomy & histology*; D018482:Muscle, Skeletal / Q000294:innervation*; D010802:Phylogeny; D023721:Tetraodontiformes / Q000033:anatomy & histology* / Q000145:classification; D014630:Vagus Nerve / Q000033:anatomy & histology*