develops from OBO_REL:part_of (UNDECLARED) cavitated compound organ pronephric mesoderm pronephros TAO:0000151 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. embryonic kidney kidney teleost_anatomy renal system coelom