From 1836 to 1841 he studied sciences at the universities of
Berlin and
Bonn and later taught classes in natural history at the
Collegium Fridericianum in Königsberg. In 1854 he became an associate professor, and in 1863 a full professor of zoology at the
University of Königsberg.[1] In 1862, he was appointed director of the zoological museum in Königsberg.[2]
The
amphipod species Gammarus zaddachi (Sexton, 1912) is named after him.[3]
Selected writings
De apodis cancriformis Schaeff. Anatome et historia evolutionis, 1841 (dissertation).
Untersuchungen über die Entwickelung und den Bau der Gliederthiere, 1854 – Studies on the development and construction of
Articulata.
Holopedium gibberum, ein neues Crustaceum aus der Familie der Branchiopoden 1855 – Holopedium gibberum, a new crustacean of
Branchiopoda.
Beschreibung neuer oder wenig bekannter Blattwespen aus dem Gebiete der Preussischen Fauna 1859 – Description of new or little-known
sawflies of Prussia.
Beobachtungen über das Vorkommen des Bernsteins und die Ausdehnung des Tertiärgebirges in Westpreussen und Pommern, 1869 – Observations on the occurrence of amber, and the expansion of
Tertiary formations in
West Prussia and
Pomerania.[4]