Berthold Hatschek

Berthold Hatschek (3 April 1854 in Skrbeň – 18 January 1941 in Vienna) was an Austrian zoologist remembered for embryological and morphological studies of invertebrates.

Berthold Hatschek studied zoology in Vienna under Carl Claus (1835–1899), and in Leipzig with Rudolf Leuckart (1822–1898).

He gained his doctorate at the University of Leipzig with a dissertation titled Beiträge zur Entwicklungsgeschichte der Lepidopteren.

Hatschek suffered from severe depression, which greatly affected his work in the latter stages of his life.

[1][2] Hatschek is remembered for his "trochophore theory", in which he explains the trochophore to be the larval form of a hypothetical organism- the "trochozoon" (which in adult form corresponded to a trochophore-like rotifer, and was the suggested common ancestor of almost all bilaterian animal lifeforms).