a1 Department of Zoology, Faculty of Sciences, University of M´alaga, P.O. Box 59, 29080 M´alaga, Spain
a2 Institute Español de Oceanografia, P.O. Box 285, Fuengirola, M´alaga, Spain
A hypothesis about the biogeography of Isistius brasiliensis in the north-eastern Atlantic is formulated through the study of frequency, size and geographic distribution of crater wounds, produced by this shark on swordfish (Xiphias gladius) and other large pelagic vertebrates. The results suggest that the bulk of the population of adult I. brasiliensis is found between 11° N and 16° N. Probably there are nursery areas in more southern latitudes. Large individuals would be frequent northwards of 16° N parallel.