The big-eyed, large-mouthed “night hawks” of the coral reef are the curious squirrelfish. During the day, they hide out in nooks and crevices along the reef tract. Found in all tropical seas, these predatory, nocturnal fish have conspicuously large eyes, stout fin spines and rough scales.
Their predominant coloration is some hue of reddish orange, occasionally with contrasting marks of black, white or yellow. Some species have a solitary lifestyle, while others usually group. They feed mainly on small invertebrates like shrimp or crab.
Squirrelfish from both the Indo-Pacific and Caribbean are commonly available through the aquarium trade. They require ledges and crevices where they can hide. Squirrelfish should be fed at night when they start getting active. They should not be kept with any small invertebrates – as predators, they may find it hard to resist such an easy midnight snack (although they are generally not that aggressive or greedy when they get fed regularly). In nature, many of these species are commonly found at a depth where light does not penetrate. However, the most commonly kept species are those that roam the reef and these are most comfortable in the normal temperature range (75-83 degrees Fahrenheit).
These fish are relatively easy to care for, but they haven’t been too popular until the idea of theme tanks (such as a “nocturnal tank”) became popular with hobbyists wanting to recreate a natural environment. In an aquarium, they tend to be timid and will get bullied if they don’t have a spot to hide. After they adapt to your tank, they are usually no problem. Feed them live shrimp and fish, and alternate with other meaty foods.
The russet squirrelfish (Sargocentron rubrum) is imported from the Pacific and Indian oceans. They are mostly red with white stripes along their bodies, and their fins also bear white markings on red.
The bigeye soldierfish (Myripistis murdjan) also comes from the Indo-Pacific region. These are schooling squirrelfish found in small groups along the coral reefs, usually nestled under the protective cover of ledges. This fish can be pink or red and has a distinct brown bar at the edge of the gill cover.
The Sammara squirrelfish (Neoniphon sammara) is also sometimes available and would be more appropriate for a nocturnal tank. This fish is usually found at depths of 150 feet or less. It has a pinkish silvery hue and a dark red to black spot on its fins. The schooling species inhabits seagrass beds, reefs, hard bottoms and seaward reefs.