BAHAMAS REEF FISH (5) – ROCK BEAUTY Holacanthus tricolor
(No, this is not all about you, Madge…)
The Rock Beauty is a species of small Angelfish, measuring up to 10 inches in length. They are bright yellow and dark blue, in varying proportions according to the stage of development, with startling blue eyelids. They are mainly sponge-feeders, but vary their diet with plankton, algae, corals and even small jellyfish. Although the cheerful colouring of the Rock Beauty might make many think “my aquarium”, their diet – particularly the need for sponges – makes them unsuitable for captivity (see below for details). They also become aggressive, and cannot be successfully bred in an aquarium which is an excellent lifestyle choice by them, and no doubt helps them to retain an IUCN listing of LC.
These fish inhabit the reefs of the tropical western Atlantic down to the northern areas of the Gulf of Mexico. Although mainly encountered on reefs, they are capable of living at considerable depths, and have been found at more than 90 meters.
Adult Rock Beauties are often found in pairs year round, perhaps suggesting a long-term monogamous bond. The pairs reproduce by rising up in the water, bringing their bellies close together, and releasing clouds of sperm and eggs. The female can release anywhere from 25 to 75 thousand eggs each evening and as many as ten million eggs during each spawning cycle. The eggs are transparent, buoyant, and pelagic, floating in the water column. They hatch after 15 to 20 hours into larvae that lack effective eyes, fins, or even a gut. The large yolk sac is absorbed after 48 hours, during which time the larvae develop normal characteristics of free-swimming fish. Larvae are found in the water column and feed on plankton. The larvae grow rapidly and about 3-4 weeks after hatching the 15-20mm long juvenile settles on the bottom.
The Rock Beauty Angelfish is considered to be a difficult fish to keep in captivity; it is ill-suited for all but the most experienced aquarists. They are highly specialised feeders that will likely perish without some marine-sponge formulation in their daily diet. They are an aggressive species. Most aquarists recommend a minimum tank size of 100 gallons. Young Rock Beauty Angelfish feed in part, on the slime of other fish and will persistently chase their tank-mates and nip at them. It is not a reef safe fish, and larger specimens may nip at or consume corals, particularly stony or soft ones, and ornamental invertebrates.
Credits: Melinda Riger of Grand Bahama Scuba, random pickings, ‘DT Wallpapers’ & wiki