develops from develops from site_of calcium ion homeostasis gill endoderm-derived structure pharyngeal gill precursor pharyngeal arch derived gill BTO:0000518 ZFA:0000354 EFO:0000933 Gill slits in the pharyngeal region of the intestine, which are also present in (at least) tunicates and acranians, are taken over to the craniote ancestor.[well established][VHOG] NCIT:C92593 branchia gills A gill that develops_from a pharyngeal gill precursor. UMLS:C0017558 TAO:0000354 The respiratory organ of most aquatic animals that breathe water to obtain oxygen, consisting of a filamentous structure of vascular membranes across which dissolved gases are exchanged. [Free_Online_Dictionary] Anatomical structure consisting of a series of membranes which allow dissolved oxygen from the water to pass into the bloodstream and carbon dioxide to pass out of the bloodstream.[AAO] VHOG:0001214 MAT:0000134 GAID:1218 UBERON:0011150 MIAA:0000134