An analysis of the marine animal remains retrieved in a sector of Huacas de Moche archaeological complex is presented. The area, 14C-dated between 470 and 600 AD (Moche IV/V), includes a poorly diversified fauna with two dominating species (donax clam and hake) despite the large number of secondary taxa (71). Such faunal spectrum corresponds to a secondary type of cropping strategy, likely to go through some kind of cultural filter (market), thus indirectly certifying the social complexity of Moche urban centres in general and the centralized and redistributive nature of Moche economy in particular. From an environmental standpoint most of the taxa indicate 'normal' (i.e. non-El Niño-Southern Oscillation (ENSO)) conditions and their abundance and ecological affinities correspond to what one could expect to find at present on the shores of the Moche Valley. The fish assemblage, moreover, suggests the existence of a low status population whereas complementary data indicate that a few of the taxa might not have had exclusively dietary connotations. Copyright © 2001 John Wiley & Sons, Ltd.