Alimentación del tiburón marrajo Isurus oxyrinchus Rafinesque, 1810 (Lamniformes: Lamnidae) en el Pacífico suroriental

In order to examine the feeding of mako shark Isurus oxyrinchus, the stomach content of 205 specimens, captured between 21° and 35°S and 78° and 118° W off Chile, during 2005 and 2006 were analyzed. The 47.8% of the sharks had food in their stomachs. The numeric, frequency and weight methods and the index of relative importance (IIR) were used to describe their diet. The diet was compared between sexes and spatio-temporal variations of the diet were also determined. The diet of the mako shark consisted of 17 prey items. Teleost fishes were the most important prey item (86.9% IIR), followed by cephalopods (12.3% IIR). Other preys were in low frequency (<1% IIR) and they were represented by elasmobranch fishes, marine birds and marine mammals. No differences in diet were found between sexes of shortfin mako, however, it was detected variation between seasons and fishing zones. According to its diet the mako shark is considered a generalist species.