Highly Underrated Fish - Black Zoster
Hemitaurichthys zoster is a common fish, with widespread distribution throughout the tropical Indian Ocean. It is replaced in the Pacific by H polylepsis (the Yellow Zoster, Shy, or Yellow Pyramid Butterfly). Large schools of Zoster Butterflies are often found associated with reef edges and drop-offs where they subsist primarily on zooplankton and algae suspended in mid water. During spawning times, distinct pairs will form. As a species they are very resilient, with a population doubling time of about a year and a half.
In The Aquarium
The Zoster Butterfly (also Black Pyramid and less commonly Brown & White Butterflyfish) is one of very few butterflies considered to be on the “Reef Safe” end of the sliding scale of acceptability with corals in captivity. They are peaceful and hardy. Topping out these attributes is their small adult size, reaching a maximum size of about seven inches in the wild, but much more commonly topping out under five inches. This all makes the Black Pyramid Butterflies an aquarium fish that isn't nearly popular enough.
As a peaceful aquarium inhabitant, they can be kept as solitary specimens, pairs, or in groups assuming a large enough aquarium is available. When acclimating, Zosters are generally quite shy, and thus overly aggressive or boisterous tankmates should be avoided. A tank with many hiding places will help them segue into their new home quickly.
Here we have excellent results feeding them a mix of meaty foods from TMC and Nutramar. We also offer a nutrient dense pellet once they are acclimated to it. There are reports of them eating aiptasia (yay!) and other soft polyped invertebrates (boo!) in aquariums, especially if underfed. I haven't personally seen this behavior; in house, all species are housed separately, in their own unique sterilized water supply, so there isn't the possibility for this type of interaction.
Biblio:
Fishbase, Tores, Armi G and Olisa, Kristine Elaine Paz. https://www.fishbase.in/summary/Hemitaurichthys-z... . Accessed 31 August 2020.
Quality Marine, Fleishauer, Eli. 27 August 2014, https://www.qualitymarine.com/News/Species-Spotli... Accessed 31 August 2020
WORMS, Froese, R. & D. Pauly, 2019, http://www.marinespecies.org/aphia.php?p=taxdetai... Accessed 31 August 2020