Squirrelfish
Squirrel fish, belonging to the order Beryciformes, are brightly colored, medium-sized fish that are active mostly at night. Squirrel fish live in rocky or coral reefs in tropical and warm temperate seas. Their most distinguishing characteristics are their large eyes and their ability to make sounds to ward off intruders.
The order Beryciformes is composed of 15 families and about 150 species of marine fish, including squirrel fishes, whalefishes, lanterneyes, and slimeheads. The fish classified within this order are widely varied and, in the past, have been placed in separate orders; in fact, their relationship is still debated. Most of the order's 15 families contain fewer than a dozen species; however, the family in which squirrel fishes are classified, Holocentridae, is the largest. It contains about 70 species.
The Holocentridae family is further divided into two subfamilies: Holocentrinae (squirrel fishes) and Myripristinae (soldierfishes). Until recently, the subfamily of squirrel fishes was thought to contain only one genus, Holocentrus. But, two new species having significant anatomical differences were found in the Atlantic. Thus, they were given separate genera, Flammeo and Adioryx. These three genera contain a total of 32 species of squirrel fish.
The Hawaiian Red and White Striped Squirrelfish has a bright red body with about 10 bright white longitudinal stripes, and a red dorsal fin with the spines tipped with white. There are two diagonal white lines on the head, one that extends below the eye from the corner of the mouth to the base of the gill plate, and one that extends upwards from the base of the gill plate to the top of the eye. The area behind the gill has a slight yellow coloration, and the gill cover has several spines.
This fish is often mistaken for its close relative, the Crowned or Diadem Squirrelfish (Sargocentron diadema). Having the same two diagonal white lines on the head, what primarily separates the two species is that this particular fish has a deeper ruby-red colored body, the stripes are more of a bluish-white color, and the dorsal fin is black, white, and red. (Click the above photos to see species comparisons).
The color of the Glass Eye Squirrelfish, also called the Dusky-finned Bullseye, changes through its life. Unlike many other fish, this fish actually becomes brighter in color as it ages. As a juvenile, the body and fins are covered in brown to red patches. With maturation the coloration changes to a bright red.
A 70 gallon or larger aquarium with plenty of live rock and room to swim is needed. A small group is suitable as long as there are adequate hiding places and space in the aquarium. It is a nocturnal fish, hiding while the lights are on and waiting for the cover of darkness to swim around in search of food. It will eat invertebrates such as worms (including fireworms), crustaceans, and serpent stars.
When first introduced into the aquarium, live saltwater feeder shrimp should be used to entice this fish to eat. Its meals should vary between live feeder shrimps, freeze-dried shrimps, and chopped marine meats that will move in the water column.