As they dive along the reef, most people are too busy looking around and too distracted by the sound of their own Darth Vader-like breathing to hear the crunching sounds that come from parrotfish. But if you take a moment, hold your breath and listen, you will hear the munching as these fish swim along the reef, scraping and biting off chunks of coral rocks with their powerful mouths, which look very much like the horny beaks of parrots and are just as tough.
Although parrotfish are herbivores, they cannot be kept in a reef tank under any circumstances. Their habit of indiscriminately biting and scraping on corals to feed on algae inevitably leads to the end of your corals. During waking hours, parrotfish essentially do nothing but graze the reef, pulverizing the coral rock and digesting any algae found in it, while continuously excreting the leftovers: a nearly-pure white carbonate sediment in the form of tiny pellets called pelloids. Parrotfish, in the Scaridae family, bite on the coral rock so much, in fact, that several scientific studies have attempted to determine what percentage of the fine calcium carbonate sediment around a reef site is actually produced by the parrotfish - by some estimates nearly 40 percent.
Keeping parrotfish is tricky business and should be attempted only by experienced hobbyists with very large tanks because of the fish's general incompatibility with other species. These fish can grow to be enormous, some reaching sizes of 2 feet in captivity, making them poor candidates for even some larger home aquaria. In nature, some species can grow to be more than 6 feet in length; however, destructive practices and increased fishing pressures along the parrotfish's reef-habitats generally no longer allow individuals to reach this impressive size.
If you can fulfill the necessities of space and food for a parrotfish, they can be quite entertaining as they are constantly on the move, looking for algae on which to graze. You can also watch them float in suspended animation at night when, during their "sleep," many species of these fish envelop themselves in a mucus cocoon that they secrete. Should you keep any species of parrotfish, you need to make sure to have a constant and ready supply of algae to keep them healthy.
Varieties of Parrotfish
Several species of parrotfish are commonly sold in aquarium stores as juveniles with the knowledge that they will probably die before they reach sizes that would present a space problem in your tank. Bicolored. Cetoscarus bicolor is a favorite among hobbyists. It is commonly found in shallow waters. As an adult, it is green, but the juvenile is white with a brown posterior edge, orange head and a black spot on its dorsal fin.
The color of a parrotfish depends on its gender. The males are typically much more colorful, sporting rich greens and turquoises or creative patterns of yellows and oranges.
Blue-spotted. Leptoscarus vaigiensis are also usually found in stores when they are juveniles. They are brown with blue spots all over the body and, like their relatives, require a ready supply of algae.
Most other species of parrotfish are just not suitable for a home aquarium. Even professional aquarists take a good deal of time to make sure that the environment they create for their species of parrotfish is perfectly suited. Trial and error experiments to maintain the health of the fish are usually the way many professionals go about first understanding how to care for the species they have. Even though all parrotfish require a "simple" diet of algae and space to grow, it is difficult to present detailed guidelines that apply to all parrotfish.