1. Fish: Sharks and big fish are voracious predators that primarily feed on other fish species. Smaller sharks and fish may prey on sardines, mackerel, herrings, and anchovies, while larger sharks and fish consume larger fish like tuna, swordfish, marlin, and even other sharks.
2. Marine Mammals: Sharks and big fish can feed on marine mammals such as seals, sea lions, dolphins, and porpoises. Some species of sharks, such as the great white shark, are known to hunt and prey on these marine mammals.
3. Seabirds: Some species of sharks and big fish may also feed on seabirds. For instance, the basking shark is a filter-feeding shark that consumes plankton and small fish, including seabirds that fly low near the water surface.
4. Crustaceans: Crabs, lobsters, and shrimps are common prey items for many fish and shark species. Sharks with powerful jaws and teeth can easily crush and consume the shells of crustaceans.
5. Cephalopods: Sharks and big fish also feed on cephalopods, including squid, octopus, and cuttlefish. These animals have soft bodies and are easy targets for sharks and other predators.
6. Marine Reptiles: Sharks and big fish can prey upon marine reptiles, including sea turtles and even smaller species of crocodiles and alligators found near coastal areas.
7. Scavenging: Some sharks and big fish are known to engage in scavenging behavior. They may feed on dead or dying fish, marine mammals, seabirds, or other animals they find in the water.
It's important to note that the diet of sharks and big fish can vary widely based on their location, the availability of prey, and their specific behaviors and preferences.