The fish species Holocentrus adscensionis, also known commonly as the squirrelfish or soldierfish, is found in the family Holocentridae. There are around 70 different species of the tropical reef squirrelfish. They have large eyes to help them see at night, are colorful (typically red and gold) with spiny elongated fins. While they can grow up to two feet in total length, they commonly do not surpass 10 inches. Squirrelfish are found distributed throughout the warm tropical waters of the Atlantic Ocean around the Caribbean, Bahamas, Florida, Bermuda, Turks and Caicos, and the Gulf of Mexico, where they typically remain at depths four feet to 40 feet where the waters are still warm but can go up to around 250 meters deep.
Squirrelfish have all five fins, a see-through pectoral fin, ventral, anal, and elongated dorsal and caudal tail fins. They also have fin spines along their spine with horizontal striped white lines along their back below them. In some species of squirrelfish, they have spines on their gill covers that are venomous that they use for self-protection. When the squirrelfish are juveniles they have more iridophores, cells that reflect light, which give them a silvery shimmer. When they transition into adults is when the red pigments of the chromatophores are more prominent distinguishing the young from the adults. The red orangey color helps them to blend in with the corals they sleep in during the day. The IUNC red list has classified squirrelfish globally as a species of least concern when they were assessed in January of 2013 but, global warming may have changed this trend as the corals are being bleached from being stressed as a result from warming ocean waters.
Squirrelfish are nocturnal carnivorous fish that hide in crevices of the coral reefs during the day to avoid predation. At night they swim through the reefs through seagrass beds hunting meroplankton, larvae and small crustaceans with the occasional small fish. When these fish are young, they tend to group together with one another which helps with protection and hunting, while adults prefer to establish their own territory and be alone. They are also able to communicate intra-specifically by producing sounds with their swim bladders. They make these sounds through vibrations to warn off predators or define their territory.