What key feature places C. daedalma within Phylum Chordata?

The presence of a notochord or a vertebral column at some developmental stage

Placement in the Phylum Chordata signifies that the Wrought Iron Butterflyfish shares fundamental embryological and structural characteristics with all other chordates, including vertebrates like humans, birds, and mammals. The defining features of this phylum include the presence of a notochord—a flexible rod providing skeletal support—at some point during the organism's development. In higher forms, this structure typically develops into or is replaced by the vertebral column, or backbone. Furthermore, chordates are characterized by having a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some developmental stage, all of which place *C. daedalma* firmly within this large phylum.