part of start stage end stage dorsal fin musculature muscle dorsal fin retractor ZFA:0005817 2014-10-27T01:05:51Z retractor dorsalis Anterior longitudinal muscles of the dorsal fin. That originates from the caudal end of the dorsal fin base, stretches along the midline between the right and left epaxial muscles, and inserts at the dorsal base of the tail fin. Contracting the dorsal retractor will lower the fin. Ceri zebrafish_anatomy unknown adult