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

A kidney formed of nephric tubules arising in the anterior region of the nephric ridge; forms only as a transient embryonic structure. [Evolution, Fourth_Edition_(2006)_McGraw-Hill, Function, Kardong_KV, Vertebrates:_Comparative_Anatomy, p.748][VHOG], Organ that serves as a transient kidney, providing osmoregulation during early developmental stages and then degenerating during metamorphosis.[AAO], The embryonic kidney, present at the level of the third somite, is composed of two glomeruli fused at the midline, two pronephric tubules, and paired bilateral pronephric ducts that modify the composition of the blood filtrate before delivering it to the cloaca for excretion.Kimmel et al, 1995.[TAO]

UBERON:0005794

uberon

embryonic kidney, archinephron, pronephron

pronephric

In all vertebrate embryos, the kidney begins with the differentiation of a few renal tubules from the anterior end of the nephric ridge overlying the pericardial cavity. (...) This early-developing embryonic kidney is called the pronephros.[well established][VHOG]

UBERON:0002120

• pronephric mesoderm

• mesonephros

• pronephric duct
• pronephric nephron
• pronephric glomerulus