develops from start stage end stage dorsal arrector TAO:0000499 dorsal arrectors ZFA:0000499 arrector dorsalis zebrafish_anatomy Acts as antagonist to the ventral arrector ZDB-PUB-050920. The muscle that acts as an antagonist to the arrector ventralis, reversing the direction of the leading edge of the pectoral fin to initiate the upstroke. arrector muscle primitive pectoral fin adductor unknown adult