Morphological data of horse-mackerel (Trachurus lathami) were analysed from samples obtained on the Brazilian continental shelf with the R/V "Prof. W. Besnard" during four oceanographic cruises in 1975. Results have shown that there are no distinct populations in the studied area. Analysing its distribution and abundance, it was verified that the species occurred in the whole área, tending to concentrate southward (28º - 30ºS). Comparing these results with those found in literature, hypothesis about the existence of another population in southern areas (south of Brazil, Uruguay and Argentina) are discussed.
