Fish vs. Fishes: What’s the Difference?

The words fish and fishes can both be plural forms of fish, but they’re not used in the same way.

Here’s the quick rule:

• Fish → the usual plural form (refers to many of the same species).
• Fishes → used when talking about different species of fish.

1. Fish: The Common Plural Form

Meaning

“Fish” is the most common plural form.
It refers to multiple fish of the same species or fish in general — not focusing on variety.

Examples (10 total)

1. We caught three fish in the river.
2. The aquarium is full of colorful fish.
3. There are many fish in the lake.
4. I saw a school of fish swimming together.
5. The fisherman sold all the fish he caught.
6. These fish are native to the Pacific Ocean.
7. She loves watching the fish in the pond.
8. The fish were hiding under the rocks.
9. Don’t feed the fish too much.
10. The coral reef is home to thousands of fish.

🧠 Tip:
If you’re talking about a group of the same kind, use fish (no “-es”).

2. Fishes: The Scientific or Species-based Plural

Meaning

“Fishes” is used when referring to different species or types of fish.
It’s more common in scientific, academic, or formal writing — or when you want to emphasize variety.

Examples (10 total)

1. The ocean contains many fishes of various colors.
2. Scientists discovered new fishes in the deep sea.
3. The Amazon River is home to hundreds of fishes.
4. These fishes represent different families in the food chain.
5. The exhibit shows tropical fishes from around the world.
6. Coral reefs are rich with fishes of all shapes and sizes.
7. Marine biologists study the migration of fishes across regions.
8. Different fishes adapt to saltwater and freshwater habitats.
9. Overfishing affects both large and small fishes alike.
10. Ancient fishes once ruled Earth’s oceans.

🧠 Tip:
If you’re talking about many species, you can safely use fishes — especially in science or nature writing.

3. Quick Comparison Table

4. How to Remember

👉 Fish = more than one fish of the same kind.
👉 Fishes = more than one kind of fish.

💡 Memory Trick:

“Fish” = same species.
“Fishes” = species plural — many kinds.

5. Common Mistakes

❌ We caught many fishes in the lake today.
✅ We caught many fish in the lake today.

❌ All the fishes in this tank are goldfish.
✅ All the fish in this tank are goldfish.

✅ Different fishes live in saltwater and freshwater environments.

6. Why It’s Easy to Mix Up

Because fish can be both singular and plural, learners assume fishes is always wrong — but it’s not!
It’s just less common and more specific in meaning.
Even advanced writers sometimes misuse it, but AI writing tools like Humanizey can spot the difference and keep your grammar natural.

FAQs

1. Is “fishes” grammatically correct?

Yes — when referring to different species of fish.

2. Should I say “two fish” or “two fishes”?

Say two fish (same species).
Say two fishes (different species).

3. Is “fishes” used in everyday English?

Rarely. It sounds formal or scientific, but you might hear it in documentaries or nature writing.

4. Is “fish” countable or uncountable?

It can be both —

• Countable: I caught three fish.
• Uncountable (as food): I like fish.

Practice: Choose the Correct Form (“Fish” or “Fishes”)

(Answers are listed at the end.)

1. The pond has many colorful ___.
2. We caught five ___ during our trip.
3. The exhibit displays ___ from across the Pacific.
4. These ___ live in freshwater.
5. Tuna and salmon are popular ___ to eat.
6. Scientists study how different ___ survive in deep water.
7. She keeps three gold ___ in her aquarium.
8. Coral reefs shelter thousands of tiny ___.
9. The biologist compared the DNA of several ___.
10. The restaurant serves grilled ___ with lemon.

Answers

1. fish
2. fish
3. fishes
4. fish
5. fish
6. fishes
7. fish
8. fish
9. fishes
10. fish