After receiving a degree, he joined the University of Jena and worked on the anatomy collections.
He collaborated with Carl Zeiss to improve microscopy for use in physiological and zoological studies.
He began to study the nervous system of fish and wrote his dissertation on the topic in 1892 titled "Über die Rami ventrales der vorderen Spinalnerven einiger Selachier".
Braus challenged the then reigning idea that muscle buds developed into skeletal elements in fishes.
Braus was influenced by Max Fürbringer and married the latter's daughter, Elizabeth.