A marginal increment analysis of otoliths from spotted sand bass collected in Bahia de Los Angeles, Baja, Mexico is being performed to validate age estimates from thin otolith-sections. Collection of specimens focused on obtaining numerous samples covering the widest size range possible to adequately describe the age composition and growth characteristics. To properly perform the marginal increment analysis, this collecting strategy was used to sample all four seasons. Otoliths from these collections are currently being analyzed for annulus counts and margin type.