Fish or fishes: Which plural should you use?

Mik aka NatureCrankByMik aka NatureCrank Updated on
The Plurals of Fish
The Plurals of Fish
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The choice between fish and fishes comes down to one thing: are you talking about a single species or a variety of them? While ‘fish’ is the safe bet for 99% of your writing, ‘fishes’ serves a specific purpose in the scientific community.

Is the plural of fish ‘fish’ or ‘fishes’?

In most everyday conversations, fish is the standard plural form. However, if you are discussing a variety of different species, fishes becomes the appropriate term.

When to use “fish” (The most common plural)

The word “fish” is what grammarians call an “invariant plural” (or a zero plural), meaning the singular and plural forms are identical. You should use “fish” in these cases:

  • Multiple individuals of the same species: If you see ten tuna swimming together, you are looking at ten fish.
  • A general group: When referring to a school of movement without focusing on diversity, “fish” is the standard term.
  • Culinary contexts: When discussing fish as a food source or a dish, always use the singular-sounding plural.
    • Example: “The menu features several fresh fish caught this morning.”
An educational infographic titled 'FISH vs. FISHES'. The left side shows a school of identical mackerel labeled 'FISH' to represent a single species or quantity. The right side shows a hammerhead shark, a clownfish, and two tuna labeled 'FISHES' to represent multiple species or biological diversity.
Use “fish” for a group of the same species and “fishes” when referring to a variety of different species.

When should you use ‘fishes’ instead?

The term “fishes” is primarily used in scientific, technical, or formal writing. It is used to emphasize diversity rather than quantity.

  • Multiple species: If you are referring to trout, salmon, and sea bass collectively, you are discussing the different fishes of the region.
  • Scientific study: Ichthyologists (scientists who study fish) use “fishes” to categorize different taxonomic groups. Scientists currently recognize over 34,000 different species of fishes worldwide.
    • Example: “The museum’s exhibit showcases the various fishes of the Great Barrier Reef.”

Quick reference guide: Grammar at a glance

ContextProper termExample sentence
SingularFishI caught one fish today.
Plural (Same species)FishI caught three fish today.
Plural (Different species)FishesThe book covers the many fishes of the Atlantic.
As food / MeatFishWe are having grilled fish for dinner.

Frequently asked questions about the plural of fish

We use ‘fish’ in this idiom because it refers to the total population as one group. Even though the sea has many species, the phrase focuses on the sheer number of ‘options’ rather than their biological diversity.

It is a real word. While children often say “fishes” because they are following the standard rule of adding “-es” to words ending in “sh” (like dishes or wishes), the word is perfectly valid in scientific and formal contexts.

Most specific fish names follow the “zero plural” rule, but not all:

  • Salmon, Trout, Cod, Tuna: The plural is the same as the singular (e.g., “three salmon”).
  • Sharks, Rays, Guppies: These usually take an “s” (e.g., “I saw two sharks”).
  • Goldfish: This can be either “goldfish” or “goldfishes,” though “goldfish” is more common.

This famous idiom, popularized by The Godfather, uses “fishes” to create a more vivid, poetic, and slightly archaic image of being underwater. In this case, “fishes” refers to the many different creatures in the ocean that would surround a person at the bottom of the sea.

When referring to fish as food, it is uncountable. You would say “I ate too much fish,” not “I ate too many fishes.” However, when referring to the living creatures, it is a countable noun with an irregular plural.

Final thoughts on fish vs. fishes

Mastering the plural of fish is a hallmark of a polished writer. While “fish” will serve you well in 99% of your daily conversations, knowing when to use “fishes” shows a deep command of English grammar and scientific nuance.

Whether you are describing a single goldfish in a bowl or the diverse fishes of the Great Barrier Reef, the context of quantity versus diversity is your ultimate guide.

Join the conversation: What is your favorite fish fact?

Grammar rules like these often have strange exceptions. Did you know that while the plural of “trout” is “trout,” the plural of “shark” is almost always “sharks”?

We want to hear from you!

  • Have you ever been corrected for using “fishes” in a scientific paper or a casual chat?
  • Is there a specific species whose plural form always trips you up?
  • Do you have a favorite idiom involving our aquatic friends?

Drop a comment below and let’s settle the “fish vs. fishes” debate once and for all. If you found this guide helpful, share it with a fellow word nerd or a fishing enthusiast who wants to get their terminology right!

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Mik aka NatureCrank

About the author
Mik is a veteran, educator, and writer who has lived off-grid and nomadic since 2020. His perspective is shaped by a diverse career in both for-profit and non-profit management, as well as years of experience as an instructor in biology, psychology, health, and ESL.

By blending his formal studies in counseling and science with the practical realities of life on the trail, Mik provides a unique, grounded approach to nature-based healing. When he isn’t documenting the natural world through wildlife photography and geology, he is exploring the intersection of scientific research and the restorative power of the outdoors.

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