Plural of Jellyfish

by Craig Shrives

The Quick Answer

The plural of "jellyfish" is "jellyfish" or "jellyfishes."
(If you're talking about the number of jellyfish (possibly of the same type), use "jellyfish." If you're talking about the number of different types, use "jellyfishes.")

The Plural of Jellyfish

The first thing to note about "jellyfish" is that it is one word, not two. Forming the plural of "jellyfish" follows the same rules as for fish, which can be "fish" or "fishes." Similarly, the plural of "jellyfish" is "jellyfish" or "jellyfishes."
  • There are five jellyfish in the tank. correct tick
    • (This is correct if there are five of them, either of the same type or different types.)
  • The aquarium has five jellyfishes at the moment. correct tick
    • (In this example, there are five different types of jellyfishes. There might be hundreds of jellyfish.)

Table of Contents

  • Are You Good at Plurals?
  • The Standard Rules for Forming the Plurals
  • Why Is There Confusion over the Plural of Jellyfish?
  • Ready for the Test?
jellyfish or jellyfishes

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The Standard Rules for Forming the Plurals

The table below shows the standard rules for forming the plurals of nouns in English.
Type Example of Type Forming the Plural Plural
Most Nouns cat
scythe		 add s cats
scythes
Noun Ending s, sh, ch, x or z jellyfish
dress		 add es jellyfishes
dresses
Nouns ending [consonant] o mango
zero
tomato		 add either s or es
(There are no rules for this - you have to know.)		 mangoes or mangos
zeros
tomatoes
Nouns ending [vowel] o patio
ratio 		add s patios
ratios
Nouns ending [consonant] y story
penny		 change the y to an i and add es stories
pennies
Nouns ending [vowel] y storey (small British flag)
donkey 		add s storeys
donkeys
Nouns ending f or fe dwarf
knife 		ves and/or s
(There are no rules - you have to know.)		 dwarfs
knives
Exceptions goose
louse 		some nouns undergo a vowel or letters change geese
lice
More exceptions salmon
jellyfish 		some nouns do not change at all salmon
jellyfish
Read more about English spelling rules.

Why Is There Confusion over the Plural of Jellyfish?

Confusion arises because people encounter both "jellyfish" and "jellyfishes" but fail to recognize the context in which each word is used. Remember that it is the same as for "fish."
fish or fishes

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See Also

Plural of fish More about the plural of fish Unusual pluralsPlural forming table Quirks with forming plurals Forming the plurals of abbreviations Forming the plurals of compound nouns