 Stomach content analysis is the most common method used, but it is not reliable for some species.In deep sea pelagic ecosystems off of California, the trophic web is dominated by deep sea fishes, cephalopods, gelatinous zooplankton, and crustaceans.Between 1991–2016, 242 unique feeding relationships between 166 species of predators and prey demonstrated that gelatinous zooplankton have an ecological impact similar to that of large fishes and squid.