Trophic dynamics and seasonal energetics of striped marlin Tetrapturus audax in the southern Gulf of California, Mexico

The analysis of consumption and energy storage of the striped marlin (Tetrapturus audax) during a yearly cycle in the southern Gulf of California, Mexico using calorimetric methodology is presented. The great diversity of prey species in striped marlin stomachs confirms their generalist feeding pattern with a high predatory capacity, foraging mainly on epipelagic organisms from neritic and oceanic zones. According to the index of relative importance (IRI), the most important prey were the chub mackerel Scomber japonicus (28%), California pilchard Sardinops caeruleus (27%), and jumbo squid Dosidicus gigas (7.7%), contributing up to 80% of the energy for striped marlin in this area. Analysis of the energetic dynamics suggested that major energy intake and storage of energy in the muscle, and ovary occur during the summer (August 1994). The southern Gulf of California is a migration zone of the striped marlin, in which the smaller marlin are consuming and storing energy to be prepared for reproduction, which may occur in an area, reported but unverified, south of the southern tip of Baja California (Revillagigedo Islands).