The Blue Fin Damsel is colored mostly in pastel shades of white, yellow, and blue. Its body is white, with a thin stripe of yellow at the top, getting thicker as it makes its way towards its adipose fin. This stripe fades to a bright, pastel blue on the very top of its body. Its pectoral fins are a translucent white, as are most parts of its adipose, anal, and caudal fins. These are bordered with yellow (in the case of the caudal), and dark blue (in the case of the anal). Its dorsal fin is colored light blue on its upper half and a darker blue on its lower half. The Blue Fin Damsel's eye falls right on the border between the yellow line and the white body.
To unlock the Blue Fin Damsel, the player must unlock Pearly Anemone and own any combination of 5 Tangs. It is unlocked at the same time as the Black And Gold Damsel, Bluegreen Chromis, and Black Bar Chromis,
2 Blue Fin Damsels are required to fuse a Neon Velvet Damsel, along with 100 seaweed and 20 clams.
The Blue Fin Damsel can be used to reveal the Cross Damsel.
The Blue Fin Damsel is based on the Bowtie Damselfish, commonly found in reefs and lagoons in the Indian and Pacific oceans. They have been spotted from Africa to Australia, and usually stay near the surface of the ocean. The appearance of the Blue Fin Damsel in-game is actually modeled after to the juvenile, as the adults are colored almost entirely dark blue. This fish is commonly bought into aquariums, where they can live up to 3 years and are provided warm water.