|Authors Note: The opinions expressed in
this article are entirely mine, and should not be construed to represent those of this
magazine or any industry or trade organization. Correspondence about this and other issues
that affect the aquarium trade is welcomed via email at email@example.com.
Marine angelfish constitute the Family Pomacanthidae,
which, for the ichthyologically challenged, is a reference to the spines (acanthus)
borne on the opercle and elsewhere on the head. They are closely related to the
butterflyfishes, Family Chaetodontidae, and once were included in the same family.
Angelfish have the rough-surfaced ctenoid scales, increasing their spininess
and, of special interest to aquarists, their ability to become entangled and often
seriously injured in nets.
All angelfish species thus far studied, several dozen in
all, are protogynous hermaphrodites, meaning that all individuals begin life as females,
with mature, larger individuals becoming male. All are also haremic, with a single male
defending a territory containing two to five females. These territories can range from an
area the size of a bathroom to one larger than a two-car garage.
All angelfish thus far observed spawn in a similar fashion,
with the pair engaging in a courtship ritual that terminates in a rush toward the surface,
at which point eggs and sperm are released. Spawning typically occurs at sunset, and the
nearly microscopic larvae that hatch out the next evening swim in the plankton for about a
month. Members of the genus Centropyge, arguably the best choices for aquarium
fish, routinely form pairs and spawn, often daily, in captivity. Maintaining two to three
females with a single male, or rearing three small fish together and allowing their gender
determination to sort itself out naturally, usually produces the desired result in a
large, well-maintained aquarium. All efforts to rear the larvae have so far been
unsuccessful. Artificial rearing of larval Pomacanthus species from Florida was
carried out successfully years ago by Martin Moe at his Aqualife Research Corporation.
However, Moe was not able to produce angelfish and make a profit, and, to my knowledge, no
one else has since succeeded in the endeavor. Thus, all angelfish available in the
aquarium trade are collected from the wild. The condition in which specimens arrive in the
shop thus greatly influences their subsequent survivability, as does the choice of
species. Some simply do not adapt to the aquarium, while others do so easily.
Marine angelfish genera differ in size, diet and behavior,
and these factors significantly affect the suitability of a particular species for the
aquarium. Here are the basics for each of the genera commonly seen in the trade:
Apolemichthys, represented by the flagfin (A.
trimaculatus) and golden spotted (A. xanthopunctatus), range up to about six to
eight inches in length. They feed on benthic invertebrates such as sponges, and adapt
poorly to aquarium diets.
Far better are the numerous species of Centropyge, commonly
known as dwarf angelfishes. From Florida and the Caribbean comes C. argus,
the pygmy angelfish, which, at under three inches, is suitable for tanks as small as 30
gallons. It feeds primarily on filamentous algae, and the small invertebrates living
within the tangle of filaments. The flame angelfish, C. loriculus, is known from
Hawaii, but most specimens in the trade come from Christmas Island. These robust little
fish, seldom reaching four inches, feed on algae and a variety of other readily available
foods and are highly recommended. Commonly imported species include C. bicolor
(bicolor), C. flavissimus (lemonpeel), C. heraldi (false lemonpeel,
Heralds), and C. bispinosus (coral beauty). Others are imported from time to
time, with rare species commanding a high price. There are 26 species of Centropyge (and
probably more) in the Indo-Pacific.
The genus Genicanthus includes several interesting
species which, according to Myers (1989) do well in the aquarium but many of the
species are rare and deep-dwelling. In these angels, the sexes are strikingly
different in appearance, whereas in most others the differences are hardly noticeable or
absent. Further, they feed on plankton in relatively open water, while most other angels
stay close to the reef. Plankton-eaters are usually good aquarium fish, but these have a
poor record. Many dealers suspect the problems may be due to poor collecting and handling
The beautiful regal angelfish, Pygoplites diacanthus,
also has a dismal record in the aquarium, probably because its diet of sponges and
tunicates if difficult to duplicate in captivity. Similarly, the Singapore angelfish, Chaetodontoplus
mesoleucos, has a poor record of aquarium survival, even though it supplements its
diet of sessile invertebrates with seaweeds.
Large angelfishes are much less popular with hobbyists
today than they were a decade ago. Part of the reason is the recent emphasis on minireef
aquariums, in which the species of Pomacanthus and Holocanthus would wreak
havoc, owing to their large size and propensity to eat benthic invertebrates, including,
sometimes, coral polyps. This also makes many of them difficult to maintain, which is a
shame, because they are among the most beautiful fish in the sea. In this group are the
blue-girdled (P. navarchus), blue faced (P. xanthometapon), emperor (P.
imperator), Koran (P. semicirculatus), French (P. paru), queen (H.
ciliaris), and rock beauty (H. tricolor) angelfishes. They range from
adaptable, in the case of the emperor, Koran, French, and queen to impossible, in the case
of the others. Best results are obtained when the aquarist begins with a three to four
inch juvenile specimen, providing it with a roomy tank of more than 100 gallons capacity
and a diet rich in seaweeds, various seafoods, and living benthic invertebrates. The
latter seem especially important for long term success with these species. Some collectors
will also collect appropriate sponges and tunicates for feeding these fishes, which, for
obvious reasons, are of interest today primarily to advanced hobbyists.
Advances in hatchery technology, coupled with a reduced
availability of wild-caught specimens, may make captive-propagated angelfish a reality for
the aquarium trade in the near future. Sources report intensive research in this area,
since many species are already popular despite their higher-than-average cost. Until that
time, choose carefully from the available offerings. You may find, as many dealers do,
that a few species of Centropyge are your best sellers.
Ten Tips for Success with Marine
species, such as any of the Centropyge angels, adapt best to the aquarium.
angels, such as Pomacanthus and Holocanthus species, need tanks of 100
gallons or more capacity.
angelfish species demand excellent water quality. Even small amounts of ammonia or other
toxic substances are harmful. They are thus generally recommended for aquarists with some
are easily intimidated by their tank mates, especially if the latter are established
residents of long standing. To overcome this problem, the angelfish should be introduced
to the aquarium in darkness. Feed the other fish well before turning out the lights, and
make sure the aquarium has plenty of hiding places, at least one for each resident fish.
most common reasons for angelfish mortality are poor water quality, followed by improper
diet. Species that feed on benthic invertebrates have difficulty adjusting to a captive
and Holocanthus angels adapt best to aquarium conditions when obtained as juvenile
specimens. In both genera, the juveniles differ markedly in coloration from the adults.
species will form pairs and spawn in a large aquarium if introduced as small specimens in
a group of three to five individuals.
filamentous algae, feed Centropyge frozen, chopped seafoods and live or frozen
Centropyge angels with a tank of 30 gallons or more.
- It may
be difficult or impossible for different species of angelfish to be accommodated in the
same aquarium. The best approach is to limit each tank to a single species. However, Centropyge
angelfish seldom bother their tank mates, and can be included in a minireef aquarium with
other fishes suited to the same environment.
Reference: Myers, Robert F. (1989) Micronesian
Reef Fishes. Coral Graphics, Guam. 301 pp.