This paper examines the Manta (Ecuador) market for landings and imports of skipjack, bigeye, and yellowfin tunas through estimation of an inverse almost ideal demand system. Skipjack landings and imports dominate the market. Manta tuna market prices show inflexible price responsiveness to changes in quantities of own species for all imports and landings except yellowfin imports. Simultaneously reducing landings and imports of all species increase vessel profits but is more than countered by economic welfare loss of supply chain firms, exporters, and consumers for a net decline in Ecuador’s economic welfare. Results show two distinct but linked market segments: (1) one well integrated by price with mutually substitutable skipjack imports and skipjack, yellowfin, and bigeye landings and dependent on skipjack imports, and (2) a niche segment centered around yellowfin imports for processors. If the Bangkok market still retains primary global price leadership, it also responds to the growing Manta market.