Due to the remoteness of these reefs, we do not often see these endemic fish in the aquarium trade, as relatively little is collected here.
The Guam damselfish has a peaceful temperament and can be kept quite well in a reef aquarium with a varied diet in a small group.
Although it is rather rare in home aquariums, it is one of the most common fish in its preferred habitat.
It can be found in large shoals along seaward reefs, on the lower reef front and underwater terraces at a depth of 3-33 meters, where it feeds on zooplankton in the open ocean.
Adult damselfish are found in exposed, seaward facing reefs on relatively barren, gently sloping terraces with scattered flat corals.
From the initial description of the endemic species it can be seen that living individuals observed at the type locality were mainly sky-blue, dorsally darker and graded to a pale yellow at the back of the body. The fins were more or less transparent.
This species was relatively common at the type locality and formed aggregations of several dozen individuals that fed on zooplankton at a short distance above the bottom.
The species name "guamensis" refers to the type locality and the only known location for this species.
With a bit of luck, this perch can be bought in the shops from time to time.