part of start stage end stage pectoral fin musculature adductor muscle primitive pectoral fin adductor Ceri ZFA:0005650 Adductor that originates at the cleithrum the muscle fibers run in sheets along the endoskeletal disk extending dorsally and caudally from its base. Distally, the muscles insert onto the fin membrane. 2012-05-08T03:51:06Z zebrafish_anatomy pharyngula:prim-25 larval:days 7-13