The Pacific jack <span name="style_italic">Caranx caninus </span>is a common species fished by artisanal fishermen off the coast of Colima, México. During 2002, monthly samples of morphometric data and otoliths were taken to determine age and growth. Seven age groups were identified. The highest growth, 14.4 cm, takes place during the first year of life. During the second year, <span name="style_italic">C. caninus </span>grows 11.76 cm; the third year 9.61 cm; the fourth 7.85 cm; the fifth 6.41 cm and sixth year 5.24 cm. The constants of von Bertalanffy´s growth equation were: L<span name="style_sub">∞</span> = 83.26 cm, W<span name="style_sub">∞</span> = 18.138 g, K = 0.202, t<span name="style_sub">o</span> = -0.283 and A<span name="style_sub">0.95</span> = 15 years. Growth curves of other species of the same genus were calculated in order to compare them with the one obtained in the present work. The gonadosomatic index presented higher values during November and May. The periods of more intensive feeding are from August to February. Rev. Biol. Trop. 56 (1): 171-179. Epub 2008 March 31. = 15 years. Growth curves of other species of the same genus were calculated in order to compare them with the one obtained in the present work. The gonadosomatic index presented higher values during November and May. The periods of more intensive feeding are from August to February. Rev. Biol. Trop. 56 (1): 171-179. Epub 2008 March 31.

Caranx caninus; age and growth; length frequency distribution; sagittae; asterisci; von Bertalanffy’s equation; longevity