50 National Marine Fisheries Service Fishery Bulletin First U.S. Commissioner established in 1881 of Fisheries and founder NOAA of Fishery Bulletin Abstract—The trophic ecology of 7 key Ontogenetic shifts and feeding strategies of species of Gadiformes, the silvery pout (Gadiculus argenteus), Mediterranean 7 key species of Gadiformes in the western bigeye rockling (Gaidropsarus biscay- ensis), European hake (Merluccius Mediterranean Sea merluccius), blue whiting (Microme- sistius poutassou), Mediterranean ling Encarnación García-Rodríguez (contact author)1 (Molva macrophthalma), greater fork- Miguel Vivas1 beard (Phycis blennoides), and poor cod 1 (Trisopterus minutus), in the western José M. Bellido 1 Mediterranean Sea was explored. A Antonio Esteban total of 3192 fish stomachs were exam- María Ángeles Torres2 ined during 2011–2017 to investigate ontogenetic shifts in diet, trophic inter- Email address for contact author:
[email protected] actions (both interspecific and intraspe- cific), and feeding strategies. The results 1 from applying multivariate statistical Centro Oceanográfico de Murcia techniques indicate that all investigated Instituto Español de Oceanografía species, except the Mediterranean big- Calle el Varadero 1 eye rockling and poor cod, underwent San Pedro del Pinatar ontogenetic dietary shifts, increasing 30740 Murcia, Spain their trophic level with size. The studied 2 Centro Oceanográfico de Cádiz species hold different trophic positions, Instituto Español de Oceanografía from opportunistic (e.g., the Mediter- Puerto Pesquero ranean bigeye rockling, with a trophic Muelle de Levante s/n level of 3.51) to highly specialized pisci- 11006 Cádiz, Spain vore behavior (e.g., the Mediterranean ling, with a trophic level of 4.47). These insights reveal 4 different feeding strat- egies among the co- occurring species and size classes in the study area, as well as the degree of dietary overlap.