What Do Fish Eat?

What Do Fish Eat
Photo by Adli Wahid

The question of “what do fish eat?” has been debated for a while. First, you should know that fish meals are just as diverse. Some fish fall into the category of carnivores, whereas others are herbivores or omnivores. 

A fish’s diet typically varies depending on its biology, size, and surroundings. Generally, fish pursue larger prey, whereas others only eat little creatures, algae, or debris.

Nevertheless, some larger fish, like whale sharks, feed on tiny sea creatures like plankton. It’s important to understand that different fish species have different dietary needs.

So, when choosing fish food for your aquarium, you must first consider the type of eater that your fish has evolved into.

It also helps to be aware of the types of food that your fish will likely encounter in the wild. Thankfully, “What do fish eat?” is answered in this article.

Why not continue reading to find out more?

5 Fish Food Variants

You should consider some dietary factors before housing a fish in your aquarium. It’s not uncommon for many fish owners to debate about what their water pet feeds on. In case you’re unaware, not all fish consume the same foods. 

The diet choice made by fish owners must meet the needs of that particular species. So, we’ve cut the list down to 5 common fish foods, which are:

1. Flakes

Most fish in community aquariums are fed exclusively on flake fish food. However, you can feed surface-feeding fish crushed or whole flakes. There’s also the alternative of breaking them up and pushing them underwater for mid-water feeders. 

Similar to pellets, a wide variety of flakes are available for specific fish. Even specific dry flakes, like goldfish-specific varieties, are available for various fish.

2. Pellets

People often feed larger aquarium fish pellet meal, which comes in both floating and sinking forms. However, most fish food producers advise feeding only as much as the fish can consume at a given time. Also, leftover food should be discarded because leftovers could contaminate the aquarium’s water as the pellets break down.

3. Freeze Dried

Given that it is rich in vitamins, minerals, and protein, freeze-dried fish food is a fantastic addition to the diets of both freshwater and saltwater fish. There are many kinds of freeze-dried fish food, but the most well-liked are tubifex, daphnia, bloodworms, brine shrimp, plankton, and krill.

4. Frozen Fish Food

If you’re still wondering, “ what do fish eat?” you should know that frozen fish food is one of the easiest ways to keep your pet fish thriving.

This type of fish food gives your pet the healthiest, most freshly made food possible. Frozen fish food preserves a lot more of its fats, proteins, vitamins, and minerals than dry or freeze-dried fish food.

Shrimp, fish, and other crustaceans make up most of the frozen meals. Foods that have been frozen are usually more nutrient-dense than foods that have been freshly prepared. Many people choose it due to this and the ease of avoiding weekly trips to the pet store.

5. Frozen Live Fish Food

Frozen fish food is often regarded as the holy grail of fish food. This is an answered prayer for those asking, “what do fish eat?” since it’s the cleanest, safest food you can have in your freezer. The advantage of frozen foods over fresh ones is that they are prepared while still being nutrient-rich.

Classification of Fish and What They Eat?

Many fish lovers should be aware that the foods their swimmers consume are determined by the category into which they fall.

Fish are categorized into three groups and are listed below, together with what they eat:

  • Carnivore
  • Herbivore
  • Omnivore


A carnivore is a type of animal that feeds mainly on other animals. Fish in this class either live in salt or freshwater. Although small fish become prey to big fish in this class, they generally eat any creature in the sea that is smaller than them.

In contrast to freshwater carnivores, which often consume smaller species of catfish, trout, or salmon, carnivorous saltwater fish devour sea creatures, including squid and other smaller fish. Salmon can also eat herring, and it has been seen that giant bluefin tuna eat dolphins.

The great white shark is no doubt the most well-known species of predatory fish. Great white sharks are vicious predators who have been known to eat whatever they can get their jaws on.

They can eat anything, including whales, seals, sea lions, penguins, and anything else. They will hunt their victim at high speeds since they can detect blood in the water miles away.

They’ve also adopted a tactic known as “bouncing,” in which they rise out of the water to attack from above before diving back down underneath their prey for an effortless kill.

Additionally, there are two categories of carnivorous fish:

  • Ambush predators 
  • Pursuit predators 

Ambush Predators

Ambush predators often hold off on attacking until there’s prey close enough to eat. They include pike fish and piranhas. When a predator goes after its prey aggressively, it moves quickly or changes its color or shape to blend in with its surroundings.


Herbivores are fish that only eat plants, like seaweed or algae. They swim more slowly than carnivores because of their food choice. These fish include herbivorous sea fish like sardines and anchovies.

You’d also find freshwater species like African catfish, Nile perch, tilapia, trout, and carp belonging to this class. 

Also, because there is a lot of plant life, herbivores are more likely to live in the shallows. This is so that they may receive the nutrients they need from the plants and water they consume.

It’s crucial to remember that herbivorous fish do not only eat plants. Some species, like black bass, can consume tiny invertebrates like insects and crabs. 


Omnivores like to chew on leaves as well as insects, but the most well-known example of this is the bass, which used to love catching bugs before it was tamed. Since this species has fangs that can rip through meat like butter, tiny fish are also an option.

Fish that are omnivores will consume anything since they have stomachs that can break down a range of food sources. Though we have no idea what else lives in the depths, omnivorous animals are most likely the most populated in the ocean.


As you can deduce from the information above on “what do fish eat?”, you must comprehend the precise nutritional needs of your fish to promote healthy growth.

Based on their environment and the species of fish, several types of food will help your fish thrive. For example, some fish need a diet high in protein, whereas others need a lot of plant material.

To offer your fish the varied diet they require, you should select from among a wide range of the possibilities we have described above. You should also know that you can manufacture your food for the best results.

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