Nutritional contribution of shellfish from the biodiversity of Todos os Santos Bay, Brazil

•Four species of native shellfish from Todos os Santos Bay were studied.•Proximate composition and fatty acid profile were determined and compared.•Goniopsis cruentata showed the highest protein content and the lowest of lipids.•The highest proportion of PUFA was verified in Goniopsis cruentata.•The findings revealed an important nutritional value of aquatic species not yet registered. The aim of this study was to evaluate the proximate composition and fatty acid profile of shellfish native to Todos os Santos Bay, Bahia, Brazil. Samples of shellfish of the species Brachidontes exustus, Mytella guyanensis, Trachycardium muricatum and Goniopsis cruentata were collected in fishing communities and analyzed for moisture, ash, proteins, lipids and fatty acid profile. The average values ​​of proximate composition analysis had the following variations: moisture, from 76.27–85.33 g/100 g; ash, from 2.13 to 3.3 g/100 g; protein, from 9.44 to 19.75 g/100 g; lipids from 0.44 to 0.99 g/100 g; and energy value of 50.22–89.37 kcal/100 g. Among the species, Goniopsis cruentata had the highest protein content (19.75 g/100 g) and the lowest lipid content (0.44 g/100 g). As for the lipid profile, it was found that: palmitic and stearic acids stood out, among saturated; margaroleic, palmitoleic and oleic acids, among the monounsaturated; and eicosapentaenoic and docosahexaenoic acids, among polyunsaturated ones - within these groups, the unsaturated were predominant. The results show the nutritional contribution of different native species, which serve as a source of proteins and polyunsaturated lipids for the local population. In addition, they contribute to fill gaps in scientific knowledge and in national food composition tables.