Juveniles of three to four inch total length are best for most aquarists. They are extremely hardy at this size, adaptive behaviorally and easy to train on non-natural foods. Tank raised individuals have been offered from time to time of smaller, but acceptable lengths, and substantial savings. Try one of these if you can find them.
Larger to largest individuals, up to sixteen inches, should only be tried in huge capacity systems, a few to several hundred gallons. Over six inches or so, specimens have a greater propensity to go on food strikes, and develop other 'anomalous' poor adaptive activities. If you want a big French, either grow one up yourself or purchase a trade-in; large wild-caught angels frequently fair poorly.
Most specimens offered have been collected by non-damaging means and adapt well to captivity. The most disqualifying criteria are labored, rapid breathing; indicative of probable handling damage and possible heavy gill-parasite load. If the individual eats readily and seems interested in it's environment, I would easily overlook a torn fin.
Chemically, French angels are extremely tolerant as marine species go. They have been used to institute nutrient cycling in place of the "standard" damsels.
Physically, also, they do well under a broad range of conditions. Temperatures in the low to upper seventy degrees Fahrenheit are within their natural range. French's are euryhaline; that is, not sensitive to a wide span of salinity. The lower range of specific gravities, 1.018-1.021 is suggested. This saves on salt mix, allows for greater gaseous diffusion, and disfavors external parasites.
Habitat-wise, the French's offered in fish stores are found associated with rocky, broken bottoms and over grassy flats from Florida to Brazil, in the Bahamas to the Gulf of Mexico. Provide numerous rock, coral et alia nooks and crannies/comfort spaces for this angel and it's tankmates.
French angels are best kept one to a tank. If they are to be mixed with angels of other genera, it is best to introduce them to as large a system as possible (fifty gallons plus) at the same time. Often, a new slightly larger individual may be added in an established angel system. Moving some of the habitat around and feeding at the time, and keeping a sharp eye are requisite. Pay careful attention if mixing angels within this genus, as one will grow more quickly and eventually do harm to it's fellows in all but the largest of systems.
Small French's display a fluttery motion, as if wagging their bodies when they swim. The sibling gray angel species do not "wag".
Juvenile French's are renowned facultative cleaners. They may be used in place of Labroides wrasses, cleaner gobies or shrimp as biological controls of parasites. In the wild they set up formal cleaning stations. Beyond three to four inches in length their cleaning activity drops off rapidly.
Moe (1976) describes natural and captive spawning for those with gigantic systems and big dreams.
A very critical and frequently the weak area in keeping marine angelfishes.
French juveniles accept live, frozen and dry-prepared foods readily. Adults can be kept in good health by feeding cut squid, crustaceans, nutritious prepared frozen foods and some substantial amounts of "green" materials. Caulerpa and Ulva algae and table-salad matter is acceptable. For optimal health and color, either a prepared sponge-containing food or live-sponge-rock must be provided. Stomach contents analysis of wild French angels reveals the importance of sponge matter to these and other Caribbean angels.
Pomacanthus paru is typically disease-resistant and long-lived, providing you start with a clean specimen and keep it under proper conditions.
One oft-cited problem is a type of blindness seems to be a result of dietary deficiency. Using a substantial amount of plant material, frozen, fresh, flake with vitamin supplements precludes this problem. Check your prepared foods label for "stabilized" vitamin C, or provide same to the water or food on a regular basis.
These fish are not easily susceptible to disease; they should be about the last one's to show evidence of the same. The common parasitic marine diseases can be quickly cured up with copper medications and/or manipulation of specific gravity.
So here is another Caribbean angel well-suited as an aquarium specimen. A good angel for the beginner marine keeper to the professionals looking for a restaurant, doctor's office show piece that is hardy and imprints on humans.
Allen, Gerald R. 1979. Butterfly and Angelfishes of the World Vol.2 Care and Keeping. Mergus Publ., West Germany
Campbell, Douglas 1981. Marines: Their Care & Keeping. Pomacanthus. Freshwater and Marine Aquarium 9/81
DeGiorgis, Joseph A. The French Angelfish: Pomacanthus paru. FAMA 3/87.
Miller, Gary 1985. Angelfish of the Caribbean. Freshwater and Marine Aquarium 8/85
McKenna, Scott 1990. Keeping the Flamboyant French Angel. TFH 1/90.
Moe, Martin A., Jr. 1976. Rearing Atlantic Angelfish Marine Aquarist 7:7, 1976
Stratton, Richard F. 1992. The Gray Angelfish, Pomacanthus arcuatus. TFH 3/92.
Tuskes, Paul M. 1980. Observations on Tropical Atlantic Angelfish on the Reef and in Captivity. Freshwater and Marine Aquarium 5/80.