mesonephros

The second of the three excretory organs that develop in a vertebrate embryo, becoming the functioning kidney in fish and amphibians but replaced by the metanephros in higher vertebrates.

Same as mesonephron.

The middle one of the three pairs of embryonic renal organs developed in most vertebrates; the Wolffian body.

The second of the three excretory organs of the developing embryo; the Wolffian body