Figure 5. Pectoral innervation in Chondricthyes (ratfish) and Dipnoi (lungfish).
(a) Pectoral innervation in ratfish (H. colliei) included four occipital (Oc1–4) and 11 spinal nerves (Sp1–11). Inset shows the branching of Oc1–4 contributing to both hypobranchial nerve and the pectoral plexus. (b) Pectoral innervation in spotted African lungfish (P. dolloi) included one occipital (Oc3) and three spinal nerves (Sp1–3). Oc3 dorsal (DR) and ventral (VR) roots emerged at the caudal end of the hindbrain. Inset shows the ventral view of Oc1–3 and Sp1. Scale bars are 5 mm.