Louis Roule (20 December 1861 - 30 July 1942) was a French zoologist born in Marseille.
In 1884 he obtained his degree in natural sciences at Marseille with a thesis on ascidians of coastal Provence. During the following year he became a lecturer at the Faculty of Toulouse. In 1891 he earned his medical doctorate with a thesis on the structure of muscle tissue, attaining the title of professor in 1892.
In 1910 he succeeded Léon Vaillant (1834-1914) as chair of zoology (reptiles and fish) at the Muséum national d'histoire naturelle in Paris, a position he would hold until 1937. During this time period he was also an instructor at the Institut National Agronomique (from 1925) and director of the laboratory of ichthyology at the École pratique des hautes études.
His earlier research dealt largely with invertebrates, and he was the author of highly regarded works on embryology and comparative anatomy. Later in his career, he focused on ichthyology, and was particularly interested in species that lived at great ocean depths. He analyzed collections gathered by Prince Albert I of Monaco and specimens obtained by the Antarctic expeditions of Jean-Baptiste Charcot (1867-1936). Roule was the first scientist to describe Grimaldichthys profundissimus, a fish species found at a depth of over six kilometers.
Roule had an avid interest in the work of French naturalists of previous generations, publishing books on Buffon, Daubenton, Lamarck and Cuvier.[1]