A method to predict the nutrient content of understudied fishes is presented in Nature Communications this week. Nutritional profiles are only known for a small fraction of the fish in the sea, and the study identifies ray-finned fish species that could meet human nutritional needs in the future.
Fish can provide essential dietary compounds including protein, fats, and various vitamins, but species vary dramatically in the amounts of these compounds they contain and, therefore, their potential value to human diets. However, laboratory studies testing nutritional content have been conducted for only a small number of fish species, partially because such testing is prohibitively expensive.
Bapu Vaitla and colleagues observed that among 371 ray-finned fish species with sufficient nutritional data, more closely related species tended to have more similar nutrient profiles. Based on this information, they then used information on the evolutionary history and relationships between species and other variables (habitat preferences, geographic range) to predict the potential nutrient content of approximately 7,500 other understudied ray-finned fish species. This approach identified families of fishes that could represent promising future sources of various essential nutrients. For example, their predictions suggest that exocoetids (flying fish), sphyraenids (barracuda), and centropomids (snook) may be high in protein, even though protein content has been measured for no more than one species in any of these families.
The authors caution that these results should not be used to suggest new fish species for commercial exploitation. Rather, the results can inform which species warrant further study for their nutritional value. These predictions may be particularly valuable in developing nations with known nutrient deficiencies and limited capacity for extensive laboratory testing.