In April 1865, Museum of Comparative Zoology founder and director Louis Agassiz set off for Brazil with his wife Elizabeth and a dozen assistants on a fifteen-month collecting expedition financed by Boston banker Nathaniel Thayer. Agassiz's primary goal was to investigate the distribution of Brazil's freshwater fish species. The Thayer Expedition Fish Drawings are a collection of 456 watercolors and pencil sketches of fish made during the expedition by Agassiz's principal artist, Jacques Burkhardt. For detailed information about a drawing, including transcriptions of annotations, select the "Full Records" option below. The drawings are held by the Ernst Mayr Library of the Museum of Comparative Zoology at Harvard University.