Q: I always thought that “fishes” was not a word. But a couple of weeks ago I read that either “fish” or “fishes” can be used in the plural form. Is this correct and which do you prefer?
A: That’s true. Both “fish” and “fishes” are legitimate plurals, according to The American Heritage Dictionary of the English Language (5th ed.) and Merriam-Webster’s Collegiate Dictionary (11th ed.)
These two standard dictionaries don’t differentiate between the two plurals, but we’ve noticed that in modern usage “fishes” is less common and used mostly to refer to more than one species of fish.
For example, the Oxford English Dictionary quotes this passage from the Encyclopedia Britannica (1957): “Most of these [temperate-water] fishes … are not good candidates for domestic fish tanks.”
Here’s another example we found on a scientific website: “Sturgeons and paddlefish are of the order Acipenseriformes, an ancient order of fishes.”
But unless you’re a marine biologist or a tropical-fish hobbyist, you probably use the plural “fish” in all cases, whether speaking of two brown trout or a brown trout and a striped bass.
Speaking of aquatic vertebrates, we recently posted an entry to our blog about the origin of the expression “sleeps with the fishes.”
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