Cardinalfish are an excellent addition to nearly any type of tank, and the Blue-Eyed or Threadfin Cardinal is no exception. They are hardy, peaceful, and visually appealing. A group of these fish will offer a mesmerizing dance of metallic blue and silver as they swim together peacefully around the tank. As with other cardinals, the Blue-Eyed Cardinal does best when added in groups of at least three, as they are schooling fish. It is suggested to offer ledges and other hiding places to help the fish feel secure. Though Blue-Eyed Cardinalfish are nocturnal, most will adjust over time to the aquarium setting and will become as active during the day as the night.
Physical: The Blue-Eyed Cardinalfish is a slender fish with a grey, nearly transparent body. They have a metallic blue ring around their eyes as well as vertical blue and orange stripes bordering their gill covers.
Diet: Blue-Eyed Cardinals are carnivorous and need a varied diet of meaty foods. Ideal foods include enriched mysis and brine shrimp, bloodworms, as well as finely chopped whole fish or shrimp. It is suggested to include a pigment-enhancing food in their diet, such as our Hatchery Diet pelleted food, to keep their iridescent shine.
Temperament: The Blue-Eyed Cardinalfish is a peaceful fish and typically won’t bother any other tankmates. Being carnivores, they have been known to occasionally go after small ornamental shrimp and/or smaller fish, but a well-fed Cardinal will likely ignore these animals.
Size: This Cardinal reaches an average maximum size of 2.5 inches.
Distribution: The Blue-Eyed Cardinal is found throughout the Indo-Pacific region, from the Red Sea to Samoa, north to the Ryukyu Islands of Japan, and south through Micronesia.
Note: The Blue-Eyed cardinal sometimes goes by a variety of different names, including the Longspine Cardinal, Blue Streak Cardinal, Threadfin Cardinal, and its previous scientific classification, Apogon leptacanthus.