Ornamental fisheries are economically viable activities in developing countries due to the fact that aquaria have become a worldwide hobby. In Mexico, the fishery has been conducted since the 1980s, especially in the Baja California Peninsula, but nevertheless, there are no adequate records of commercial production, or about the economic gain due to the exploitation of the resource. The objective of this paper was to calculate the maximum allowable catch for the five ornamental fishes included in the NOM-059-SEMARNAT (protected by federal mandate), and the net monetary gain that the resource might generate. Censuses (N=1 610) were conducted in 21 reef sites of the Mexican Pacific and Gulf of California in order to estimate population density of each taxon; also, natural mortality rate (M) was calculated from maximum size (L∞), individual growth rate (k) and temperature (C), and the total allowable catch was estimated on the basis of M. Finally, considering the prices of the species paid to fishermen at the beach, an estimation of the economic value of a single fishing season for an area of 220 hectares (representative of the catch area assigned in average to a cooperative in Mexico) was produced.  The results indicated that the areas with the best economic potential were Encantadas Islands, Los Angeles Bay, and San Lorenzo Archipelago (all in the state of Baja California). Outside of the gulf (where no legal ornamental fisheries exist) the potentially more rentable locations were Marietas Islands (Jalisco), and the Revillagigedo Islands. Aquarium fisheries may be a viable activity in several of the analyzed areas of the country, however, the potential gain that harvest represents is not enough to fully sustain an organized group that would perform it; for that reason the ornamental fishery should be seen as an alternative commercial activity. Finally, to guarantee this activity to be a rentable and sustainable fishery, we recommended that, the existing rules defined by the Mexican federal government should be applied to control the catch quotas.

Keywords: Holacanthus clarionensis, Holacantus passer, Pomacanthus zonipectus, Chromis limbaughi, Opistognathus rosenblatti, MAQTRAC.