Are Fish Animals? Here's What Science Says

In the U.S., many people don't consider fish to be animals. This misconception often stems from cultural norms and dietary habits. However, science tells a different story. Let's dive into the facts.

🧬 Fish Are Animals – According to Science

Biologists classify fish as animals. In fact, fish belong to one of the six main groups of animals: mammals, birds, reptiles, amphibians, fish, and invertebrates. While the flesh of fish might not always be called “meat,” fish are undeniably animals with brains and the ability to feel pain.

Scientists agree that the animal kingdom includes a vast range of creatures, from microscopic plankton to whales. Fish, with their unique adaptations like fins and gills, are textbook examples of what it means to be an animal.

🧪 What Makes an Animal an Animal?

To qualify as an animal, organisms must meet specific criteria:

1. Made of multiple cells
2. Consume food for energy
3. Reproduce sexually
4. Composed of cells without walls
5. Capable of motion at some stage of life
6. Respond to external stimuli

Fish tick all these boxes, making them animals just like pigs, parrots, and people.

🐠 The Language Problem

Part of the confusion comes from how we talk about fish. Terms like “seafood” and “catch of the day” reduce fish to commodities, stripping them of their identity as living beings. These phrases condition us to see fish as food first, and animals second.

Fish are also less visible in conservation campaigns compared to pandas, elephants, or tigers. This absence from public consciousness reinforces the misconception that they’re less important, or less “animal.” Shifting the narrative begins with recognizing fish as living beings with intrinsic value.

🧠 Fish Have Brains and Feel Pain

Yes, fish have brains — just like most animals. Scientific evidence suggests that fish do feel pain. They have neurons called nociceptors that detect injury and stress. In fact, fish produce pain-relieving opioids, much like mammals.

Fish can recognize faces, form social bonds, and even display personalities. These emotional and cognitive abilities challenge our assumptions about what it means to be a sentient animal.

🧭 Why Do Some People Think Fish Aren’t Animals?

Some people associate animals with mammals, like dogs or cows, and may not realize that the animal kingdom includes fish and marine life.

Another reason why people may think that fish are not animals is because of the Catholic doctrine which states that Catholics must abstain from eating meat on Fridays, but that they can eat fish. This may cause some people to wrongly conclude that fish isn’t considered to be meat.

🍽️ Is Fish Considered Meat?

The answer depends on the context:

• Religious Context: Meat is defined as warm-blooded animal flesh, so fish isn’t considered meat.
• Scientific Context: Meat includes all animal flesh, including fish.

Even dictionaries differ on this. For example:

• Cambridge Dictionary defines meat as “the flesh of an animal used for food,” including fish.
• Merriam-Webster specifies meat as “the flesh of mammals, as opposed to fowl or fish.

🌊 The Bottom Line

Fish are animals. They feel pain, have brains, and meet all the biological criteria for being animals. While some definitions of meat exclude fish, this doesn’t change their status as animals.

Whether or not you choose to eat fish, understanding their biology, sentience, and the environmental impact of fishing can help you make informed decisions.