Domino Damselfish Facts

The domino damselfish is a hardy saltwater marine fish – with a scientific name of Dascyllus trimaculatus. Even so, most enthusiasts will know it as the three spot domino damselfish.

They are prevalent in their natural geographical ranges of the Indo-Pacific Ocean, Australia, Southern Japan, and East Africa. But, they are also kept in aquarium habitats by keen hobbyists worldwide.

In the home aquarium, domino damselfishes enjoy having an anemone present. So, installing some carpet anemones, coral heads, or sea urchins is certain to make this species feel at home in the tank.

The 3 spot damsel thrives in the wild at depths from as little as three feet down to two hundred feet. It is diurnal, which means it is active during the hours of daylight.

Note: These aggressive little fishes inhabit fringing coral reef formations and rocky outcrops. They often congregate to form large colonial gangs around the reef.

Domino Damsel Aggressive Behavior

The behaviour of the domino fish is less aggressive and less antagonistic as a juvenile. But, domino damselfishes are well-known for being a dominant and feisty territorial fish when they mature.

Facts about domino damselfish species.

In fact, the 3 spot damselfish – otherwise called Stegastes planifrons – is one of the most protective of the species.

It will defend its reproductive sites and food sources. Sometimes so, with a sharp bite given to any unwelcome intruders.

They usually grow up to five (5) inches in length and around 4 inches for specimens kept in captivity. You can identify the domino damselfish species by its distinct coloring and physical characteristics. That being a black body with bluish scales and three large white spots (like dominoes).

There is one white spot on each side below the fish’s dorsal fin. Another single spot is in the middle of the head above the eye.

The dark gray colouring of the Domino dascyllus changes as it matures. With age, their bodies tend to appear browner in coloring and the spot’s brightness begins to fade.

Like most saltwater marine damselfishes, they are quite peaceful as juveniles. But, they tend to become more aggressive as they mature.

Juvenile domino damsels are happy living in large sea anemones or coral heads in the wild. It is not uncommon to find anemones with twenty or more young domino damsels living inside it.

The Foraging Domino Fish Diet

Domino damsel fish are omnivores and planktivores feeding in the water column. They eat copepods, planktonic crustaceans, benthic algae, and they graze on weeds.

Furthermore, they will forage for food almost every hour that is light. They will search tirelessly for their favourite diet – caridean shrimp.

Like most damselfish species, the domino damsel also forages higher up in the water column. It spends time closer to the surface when the water current speeds are slow. Moreover, foraging shallower increases the likelihood of finding large flows of plankton.

Domino Damselfish Reproduction

Female domino damselfish ‘temporarily’ vacate their regular clutches while they are spawning. Then, having deposited their eggs inside the male territories, they quickly return to safety to avoid predation.

Because females are so exposed during the spawning season, they tend to have a higher mortality rate than the male of the species.

Male damselfish play the defensive role of the species. They swim in a circular pattern above their nests until the tiny larvae hatch.

During this time, male damsels often compete viciously against each other. The aim is to control the reproductive territorial habitats on the seabed.

Less aggressive, or unsuccessful combatant individuals, often find themselves excluded from these breeding activities. They exist somewhat at risk to predation as floating members of the domino damselfish population.