Ferdinand Carl Valentin Haecker (15 September 1864 – 19 December 1927) was a German zoologist, reader at Freiburg University from 1892.
In 1900, he became professor at the University of Applied Sciences Stuttgart and in 1909 at Martin Luther University of Halle-Wittenberg.
He was president of the Deutsche Zoologische Gesellschaft from 1922.
Haecker's contributions span the fields of ornithology,[1] plankton (Radiolaria)[2] cell biology,[3] developmental physiology, genetics[4] (where he established the subfield of phenogenetics[5]).
He also published a historical treatise on Goethe's work on morphology.