Seahorse is a symbol of strength and good fortune, especially for mariners and sailors. In Greek mythology, large seahorses used to carry the chariot of Poseidon. According to the legends of Celtic folktales, sea nymphs used to ride them to come to the rescue of ship wreckers in need, hence that is where their good fortune originates.
Distinctive in its appearance and features, the author finds a seahorse an embodiment of uniqueness, as that is what makes it stand out from the rest.