Abstract
Stellifer naso is known from the State of Bahia (Brazil), but there is a lack of an accurate definition of its type locality. Thayer's expedition (around 1865-1866), led by Louis Agassiz and staff from the Museum of Comparative Zoology (MCZ, Harvard University), intended to explore Brazilian fauna and flora, with most of its material housed in the MCZ and used to describe several species, including S. naso. Examination of specimens from the original description of that species, housed in the MCZ and the Smithsonian National Museum of Natural History, helped review the accurate point of origin for such specimens. A combination of data from reproductive biology and the history of the region further support the actual type locality of S. naso as Iguape Bay, with an error radius of 2.5 km. Damming in the Paraguaçu River in the early 1980s might have had an impact on the morphological variation over time recorded to this species.