Three Stripe Damsel

The Three Stripe Damsel, commonly known as the Humbug Damselfish, is one of the most iconic and easily identified reef fish in the Indo-Pacific. Its bold pattern of three black vertical bars on a clean white body creates a stark, graphic appearance that has made it a popular aquarium species for decades. This hardy little fish reaches about 3 inches in length and is a staple of the marine aquarium trade, widely available and inexpensively priced.

In the wild, Dascyllus aruanus is one of the most abundant reef fish across its enormous range, from the Red Sea and East Africa to the central Pacific. It forms tight aggregations around branching coral heads, particularly Acropora, Stylophora, and Pocillopora species, rarely straying more than a few inches from the protective coral branches. These groups typically consist of one dominant male, several females, and numerous juveniles, with a strict social hierarchy that determines access to food and shelter. When threatened, the entire group retreats into the coral branches simultaneously.

Despite its appealing appearance and extreme hardiness, the Three Stripe Damsel is notoriously territorial and aggressive for its size. In the aquarium, it will vigorously defend its chosen coral head or rock formation against all comers, including fish significantly larger than itself. This behavior makes it a challenging community fish, though its small size limits the actual damage it can inflict. It is best added last to a community tank and housed with moderately assertive species. The Three Stripe Damsel is completely reef-safe and makes an excellent inhabitant for reef aquariums where its territorial tendencies can be managed through careful stocking and adequate space.