located in develops from kidney pronephros pronephric Once the more complex mesonephros forms the pronephros undergoes apoptosis in amphibians. In fishes the nephron degenerates but the organ remains and becomes a component of the immune system[Wikipedia:Pronephros]. // TODO - check developmental relationships. Note that we previously include the ZFA/XAO terms under the more specific 'pronephric kidney', but these are now merged. TODO GCI: relationship: capable_of GO:0030104 intraembryonic coelom mesoderm-derived structure developing anatomical structure pronephric mesoderm rostral part of nephrogenic cord