Fish - Vine's Expository Dictionary of New Testament Words
Fish
[ 1,,G2486, ichthus ]denotes a fish," Matthew 7:10; Mark 6:38, etc.; apart from the Gospels, only in 1 Corinthians 15:39.
[ 2,,G2485, ichthudion ]
is a diminutive of No. 1, "a little fish," Matthew 15:34; Mark 8:7.
[ 3,,G3795, opsarion ]
is a diminutive of opson, "cooked meat," or "a relish, a dainty dish, especially of fish;" it denotes "a little fish," John 6:9, John 6:11; John 21:9-John 21:10, John 21:13.