The opisthonephros is the functional adult kidney in lampreys (cyclostomes), most fishes, and amphibians. [1] It is formed from the extended mesonephros along with tubules from the posterior nephric ridge. [2] The functional embryonic kidney in anamniotes is the pronephros.
Kerr coined the term ‘opisthonephros’ in 1919. [3] In 1949, Hyman wrote the opisthonephros “has used up the mesomere tissue from which in amniotes both mesonephros and metanephros come.” [3] Some accounts call opisthonephros the ‘mesonephros’, but the opisthonephros in anamniotes (lampreys, fish, and amphibians) differ considerably than the mesonephros in amniotes ( reptiles, birds, and mammals). [1] Thus, the term mesonephros is usually reserved for the embryonic kidney of amniotes. [1]
The mesonephros and metanephros of amniotes are derived from different parts of the anamniote opisthonephros. [1] The metanephros is derived from the posterior part of the opisthonephros. [1] In amniotes, most of the former opisthonephros became the epididymis, and the archinephric duct became the vas deferens. [4]
The opisthonephros is the functional adult kidney in lampreys (cyclostomes), most fishes, and amphibians. [1] It is formed from the extended mesonephros along with tubules from the posterior nephric ridge. [2] The functional embryonic kidney in anamniotes is the pronephros.
Kerr coined the term ‘opisthonephros’ in 1919. [3] In 1949, Hyman wrote the opisthonephros “has used up the mesomere tissue from which in amniotes both mesonephros and metanephros come.” [3] Some accounts call opisthonephros the ‘mesonephros’, but the opisthonephros in anamniotes (lampreys, fish, and amphibians) differ considerably than the mesonephros in amniotes ( reptiles, birds, and mammals). [1] Thus, the term mesonephros is usually reserved for the embryonic kidney of amniotes. [1]
The mesonephros and metanephros of amniotes are derived from different parts of the anamniote opisthonephros. [1] The metanephros is derived from the posterior part of the opisthonephros. [1] In amniotes, most of the former opisthonephros became the epididymis, and the archinephric duct became the vas deferens. [4]