Friedrich Dahl

Karl Friedrich Theodor Dahl was a German zoologist, and in particular an arachnologist.
The son of a farmer, Dahl studied at the universities of Leipzig, Freiburg, Berlin and Kiel. His dissertation was "Beiträge zur Kenntnis des Baus und der Funktion der Insektenbeine". He became a Privatdozent in 1887; with a habilitation thesis "Ueber die Cytheriden der westlichen Ostsee". Around this time he traveled to the Baltic states and to the Bismarck Archipelago near New Guinea. He was also interested in biogeography.
On 1 April 1898 Dahl became curator of arachnids at the Natural [History Museum, Berlin|Museum für Naturkunde] in Berlin, where he worked under his former teacher, the then museum director Karl Möbius. Dahl remained in Berlin until he retired, and his type collection is held in that museum.
Although he described many animal groups, Dahl concentrated on spiders. He was also interested in the biogeography and animal behaviour.
On 19 June 1899 he married Maria Dahl, a co-worker at the zoological institute of Kiel. She also published several works on spiders.
He is commemorated in the scientific names of a species of snake, Tropidonophis dahlii, and a species of bird, the Bismarck fantail ''.