What Do Wild Fish Eat? – The vast majority of fish are omnivores. dokosola/Shutterstock.com In the wild, fish will eat virtually anything they can catch or find. As the majority of fish are omnivores, they are not particularly picky eaters. Nevertheless, the majority of fish consume between 40 and 50% protein, with the remainder consisting of carbohydrates and fats.
There are exceptions, but very few fish consume a predominantly plant-based diet. Parrotfish, for instance, consume coral, whereas damselfish consume algae that consume coral. In contrast, certain fish, such as sharks, subsist almost exclusively on the flesh of other fish, mammals, and other animals. With the exception of fish that have evolved to eat a specific food, fish typically consume whatever foods are most abundant in their environment.
Scale-eating fish, for example, primarily target and subsist on the scales of other fish. On average, several foods appear frequently on the list of fish diets. Insects, such as flies, mayflies, midges, crickets, grasshoppers, and beetles, are consumed by fish.
Worms, such as superworms, mealworms, bloom worms, leeches, and nightcrawlers, are consumed by many fish. Some larger fish prey on smaller rats, mice, snakes, frogs, turtles, and other fish. Large predators, such as sharks, prey upon larger mammals, such as seals and sea lions, as well as large fish and even birds.
The majority of fish swallow their food whole and only use their teeth to grasp and hold prey. 
What should I feed my fish?
What Do Baby Fish Eat? – In general, baby fish consume the same foods as their adult counterparts. However, their diets are more restricted because they cannot pursue larger prey. Baby fish typically begin eating algae, microorganisms, worms, tiny crustaceans, and insects shortly after hatching.
Their instincts direct them to hunt smaller prey, which may include young fish. Baby fish should be fed high-quality baby fish food or fish flakes that have been finely ground. In addition, they can consume zooplankton shrimp larvae. It is crucial to closely monitor the feeding habits of young fish, as they must eat multiple times per day.
Always consult your veterinarian or an expert at your local pet store before introducing new foods to your baby fish. mcmortgreen/Shutterstock.com We appreciate your reading! Have some feedback for us? Contact the editorial staff of AZ Animals.