[1] Lahille studied science and medicine at the University of Paris, receiving his doctorate in 1891[2] while publishing extensively.
[1] When in 1893 the Natural History Museum of La Plata in Argentina sought a scientist to head the newly formed zoology department, they found him in Lahille, already with eight years of experience in the marine laboratories of Banyuls-sur-mer and Roscoff, and sixty published works with the thesis on tunicate taxonomy (Recherches sur les tuniciers[2]) being the most ground-breaking.
Lahille subsequently became head of the Fish and Game Department within the Argentine Ministry of Agriculture,[1] where he became involved in new fields of biological research.
In May 1910 he was appointed professor of zoology at the Faculty of Agriculture and Veterinary Medicine of the University of Buenos Aires.
[1] Among the areas Lahille worked in are studies on worms in apples and pears, parasitic diseases in agriculture and the fertility of ticks in different life periods, but also largely on invertebrates, such as echinoderms, molluscs, crustaceans, hexapods, arachnids and tunicates.