The Mertens Butterflyfish is a blue silver coloration with black margins on its body scales. This gives a crisscross pattern and pearly sheen. Most of its posterior is orange and it has a silver-edged black stripe through the eye. They do well in an aquarium providing that it is well-maintained and relatively peaceful.
The Mertens Pearlscale Butterflyfish is part of the "xanthurus complex" consisting of lookalike species with similar latticed pattern. The Mertens Pearlscale Butterflyfish is a great example of a lookalike. The Crosshatch Pearlscale Butterflyfish is distinguished by a white-rimmed, dark oval spot located slightly askew behind the eye band. Also, upon careful observation, the Crosshatch Pearlscale Butterflyfish has a true reticulated (net-like) or crosshatch pattern while the lookalikes have a distinct chevron or V-shaped pattern.
It may be kept with other Butterflyfish if they are introduced to the tank at the same time.
The Mertens Butterflyfish is not considered reef safe.
The diet of the Mertens Butterflyfish should include various chopped meaty preparations.