What do all fish eat?

It's impossible to say what all fish eat, as there are over 34,000 species of fish with incredibly diverse diets. However, we can broadly categorize fish into several groups based on their feeding habits:

Carnivores:

* Predators: These fish hunt and eat other fish, invertebrates, and even small mammals. Examples include sharks, barracuda, tuna, and pike.

* Plankton feeders: These fish consume tiny organisms called plankton, including phytoplankton and zooplankton. Examples include herring, anchovies, and krill.

Herbivores:

* Algae eaters: These fish graze on algae, seaweed, and other aquatic plants. Examples include parrotfish, surgeonfish, and sea turtles.

Omnivores:

* Mixed feeders: These fish have a more varied diet, consuming both plant and animal matter. Examples include catfish, carp, and goldfish.

Detritivores:

* Scavengers: These fish feed on dead organisms and decaying matter. Examples include eels, catfish, and some types of sharks.

Parasitic fish:

* Blood suckers: These fish feed on the blood of other fish. Examples include lampreys and some species of catfish.

Beyond these categories, there are many other fascinating feeding adaptations among fish. Some species are specialized feeders, like the butterflyfish that uses its long snout to extract food from coral crevices, or the anglerfish that uses a lure to attract prey.

Therefore, the answer to your question is complex and depends on the specific species of fish. If you're curious about the diet of a specific fish, you can research it online or consult with a marine biologist.