The Whitemargin Unicornfish is a species of coral reef fish with a unique morphological appearance.
"It's most distinctive trait is the horn-like protuberance on its head. Although this horn is not present on young fish, it develops gradually as the fish grows to adulthood.
Another distinctive feature is the tailfin, which extends in thin stands in the upper and lower sections.
In order for saltwater fish to prevent dehydration, they must take in saltwater. They then excrete excess salt using special cells known as chloride cells.
Freshwater fish have few chloride cells, or none at all, and so cannot survive in saltwater."
A small group of Whitemargin Unicornfish can be seen in the Ocean's Graveyard area, floating above the trapdoor on the deck that leads to the inside of the ship, only during the daytime. They can also be seen nearly everywhere in Manoa Lai during the winter months.
A small group can be seen in Endless Ocean 2 floating around and in the Mouth of Truth, but only during the daytime.
They float about in loose groups, swimming slowly and moving individually, unlike schooling fish, which have synchronised movements. The player can obtain their trivia by feeding them.