1. There are starfish, jellyfish, sea anemones, sea horses, sea urchins, etc in the ocean.
2. There are starfishes, jellyfishes, sea anemones, sea horses, sea urchins, etc in the ocean.
(Which expression is correct?)
Common usage for the plural of fish, starfish, and jellyfish is the same: fish, starfish, and jellyfish.
So 1) is correct. I remember in the King James version of the Bible, fishes was plural, but no longer.
etc. is an abbreviation and has a period following.
Since "etc." is an abbreviation for the Latin, "et cetera," it is typically followed by a period.
I hope this helps a little more. Thanks for asking.
In addition to adding a period after "etc." you also need to add a comma since you are ending a series.
"...sea urchins, etc., in the ocean."
From http://www.bartleby.com/141/strunk.html
in Section 3:
"The abbreviations etc. and jr. are always preceded by a comma, and except at the end of a sentence, followed by one."
Both expressions can be considered correct, but it depends on the specific context and grammatical convention being followed.
1. "There are starfish, jellyfish, sea anemones, sea horses, sea urchins, etc in the ocean."
In this expression, the plural forms of the words "starfish," "jellyfish," "sea anemones," "sea horses," and "sea urchins" are used without adding an additional "es" to the end of the words. This follows the general rule of forming plurals in English, where typically an "s" is added to the end of the word.
2. "There are starfishes, jellyfishes, sea anemones, sea horses, sea urchins, etc in the ocean."
In this expression, the plural form of each word is created by adding "es" to the end of the word. This form is less common and follows irregular pluralization patterns in English, as some words ending in "sh" or "ch" may require adding "-es" to form the plural.
Generally, it is more common to use the first expression, without adding an "-es" to create the plural forms of these words. However, the usage can vary depending on regional dialects or personal preferences.