Rock Beauty Angelfish (Holacanthus tricolor)On one of my earliest dives down in the Florida Keys back in the 1990s, a gorgeous yellow and black angelfish caught my attention as I drifted over a section of reef. In my mind’s eye, I envision the angel hovering boldly above a large barrel sponge, but I can’t be sure whether that’s actually how it happened or just an idyllic memory. In any case, I was taken with its distinctive appearance and wondered whether it might make a good aquarium candidate. As anyone familiar with the fauna of the tropical western Atlantic has already guessed, the angel I saw back then was a rock beauty (Holacanthus tricolor)—a species that, unfortunately, tends to fare poorly in marine aquaria and is generally best left to advanced fishkeepers or, better yet, in the ocean where it can beguile other divers. I’ll get into why in just a moment.Physical traits H. tricolor is laterally compressed (flattened from side to side) and, in typical angel fashion, sports a sharp, backward curving spine on the gill cover (operculum). As alluded above, this species is yellow on the anterior portion of the body and on the caudal fin and black from behind the gills to the caudal peduncle (base of the tail). The margin of the anal fin, the edge of the operculum, and the opercular spine are orange.
Overfeeding is sometimes necessary to entice a finicky fish to eat, especially if they have little nutritional reserve to begin with, such as butterflyfishYou’ve heard time and again, here at Saltwater Smarts and elsewhere, that overfeeding is one of the surest ways to cause ill health in fish and pollute your aquarium water. The usual recommendation is to offer foods in very small quantities that the fish can consume within just a few minutes. And when it comes to reef systems, we tend to be especially sparing with fish food in order to maintain the lowest possible level of dissolved nutrients. While it’s generally good advice to feed fish sparingly and judiciously, there are certain times when it doesn’t pay to be stingy with the victuals. In fact, sometimes you really have to feed on the heavy side and then step up your water changes and other water-quality-management techniques to compensate for the increased dissolved pollutants. Here are just a few examples off the top of my head:When feeding a finicky fish in quarantine Of course we’re supposed to make sure fish are eating at the LFS before we acquire them, but over the years I’ve had various specimens simply turn off the “feeding switch” upon arriving in quarantine (and in a few cases after being moved from quarantine into my display tank), possibly due to the stress of transfer or because they simply didn’t recognize the stuff I was offering as edible. When this situation arises, it can take a lot of coaxing with different types of food at various times throughout the day to entice the specimen. In other words, you may end up introducing a lot more food to the system than is typically considered acceptable before the fish finally resumes feeding.