First report on the swim bladder index, proximate composition, and fatty acid analysis of swim bladder from cultured Totoaba macdonaldi fed compound aquafeeds

Totoaba (Totoaba macdonaldi) is a large species of croaker, endemic to the upper Gulf of California in Mexico, which has been under extreme poaching pressure due to its highly valuable swim bladder, or buche. For more than 20 years, totoaba aquaculture has been developing as one, among many, conservation strategies in the ongoing management of the species. Competing with illegally poached buche requires farming high quality product. This study provides the first report of the influence of alternative aquaculture feeds - fishmeal versus soy protein concentrate (SPC) - on key cultured totoaba traits that affect the market value of its swim bladder. Since the price of farmed buche is key to the successful displacement of illegally poached product, options for replacing expensive fishmeal are key to conservation success. A variety of characteristics related to buche size and quality were affected by diet composition, but partial inclusion of soy protein as a substitute for fishmeal can produce buche of comparable quality to product grown from more expensive fishmeal diets. These findings highlight a path for diet changes to produce high value totoaba swim bladders from aquaculture at substantially lower costs.