I wrote an
article back in 1998 on the regal angelfish (Pygoplites
diacanthus) for the now defunct publication, Aquarium
Frontiers.To
this day, that article still generates interest and questions.I imagine this is because the regal angelfish is one of the
most beautiful fish in the sea and desired by many marine
aquarists.Unfortunately
this gem is not easy to maintain in captivity.I’ve kept a regal angelfish for seven years now and
learned a few tricks and techniques along the way.
The
regal angelfish is the only member of the genus Pygoplites,
which is part of the greater family of angelfish, Pomacanthidae.It can be found throughout the Northern and Western Indian
Ocean, the Red Sea, and the Indo-Pacific Ocean.Regal angelfish are not sexually dichromatic, but color
differences do exist between specimens from the Red Sea/Indian
Ocean and those originating from the Indo-Pacific region.Red Sea/Indian Ocean specimens exhibit a bright orange
coloration throughout the ventral area and under the mouth.Those from the Indo-Pacific region are blue-gray in this
area.The distinction
is clear in adult specimens but somewhat harder to discern in
juveniles.
Juveniles
are similarly colored to adults except for a large false eye-spot at the
base of the dorsal fin.This
fades as the fish matures and it’s gone by the time the fish reaches a
length of 6-7 cm.This is
atypical for Pomacanthids.Most
of the bigger angelfish don’t transform to adult coloration until
they’re much larger in size.
The
author’s regal angelfish (Pyglopites
diacanthus) can be seen here sharing Pro-V gelatin food
with the resident tangs in this 500 gallon reef aquarium
Regal
angelfish naturally inhabit areas of rich coral growth in both
lagoons and outer reefs from 1 to 50 meters deep.They are commonly observed as solitary individuals and in
pairs, but can also be seen in small groups.These haremic groups typically consist of one male and two
or more females.The
maximum adult size is reported to be between 20 and 30 cm (8 and
12 inches).All regal
angelfish are relatively cryptic and never stray far from a reef
crevice.Juveniles,
in particular, are more guarded than adults and often found in the
vicinity of caves.They
graze on benthic invertebrates in nature, with a particular
fondness for sponges and tunicates.Recently acquired specimens can be observed eating with a
side-ways ripping motion, even when feeding from the water column.This is how they tear pieces of sponge from the reef.They lose this habit as they become accustomed to a diet of
prepared foods.
Regal angelfish don’t
adapt easily to captive life.It’s one fish that almost requires a quarantine period in
order to become used to aquarium conditions and be treated
medicinally if necessary.I
suggest a quarantine tank of not less than 20 gallons with a few
hiding places created from PVC pipes or fittings.Alternatively, I’ve found that a refugium aquarium makes
a great quarantine tank for regal angelfish and many other
sensitive fish.There
are plenty of natural foods available to sustain the fish while it
becomes used to prepared foods, and refugium aquariums generally
have good water quality.It’s
important to maintain as stress-free an environment as possible
during the quarantine period.If, after 4 to 6 weeks, the fish is eating well and shows
no signs of bacterial infections or parasites, it can be released
into the display aquarium.
Proud sponsor of this column
:The author has kept this regal
angelfish (Pyglopites
diacanthus) for over 7 years in his reef aquarium.Here it is enjoying Pro-V gelatin food attached the
front glass along the left side of the reef aquarium.
Adult
regal angelfish should be maintained in a reef aquarium of at
least 75 gallons.Juveniles
can live comfortably in 50 gallon aquariums but a bigger aquarium
is always better.Larger
aquariums offer more feeding opportunities, more stable water
conditions, and more comfort and security in the form of hiding
spaces.
It’s
difficult to duplicate the natural diet of regal angelfish in
captivity.I’ve
found that they will thrive in captivity on a varied diet
consisting of food items such as red nori seaweed, Pro-V gelatin
food, mysis shrimp, and chopped krill.I roll sheets of the dried red macroalgae (Seaweed Selects
from Ocean Nutrition) and place it in a clip or rubber-band it to
a small rock.My
regal angel eagerly eats it.It’s a great source of carotenoids (natural coloring
agent).I also feed
Pro-V gelatin food in a clip.Pro-V is a mix of seaweed and vegetables in a gelatin base.It has the consistency of a sponge when defrosted, which
may be why it appeals to regal angels.Regal angels don’t compete well for food against
quick-feeding planktivores in a community aquarium.These feeding techniques will ensure that they get a
sufficient amount of food.
Unless you have a
known pair, it’s not safe to mix two or more regal angels in the same
aquarium, regardless of size.Regals
are relatively shy fish and they’re easily spooked by larger, more
aggressive fish.They will not thrive in an aquarium with aggressive feeders
or fish with belligerent personalities, such as triggerfish and large
wrasses.The best chance
for success is if the regal angel is the largest fish in the aquarium.Over the years I’ve been forced to remove both a hepatus tang (Paracanthurus
hepatus) and an achilles tang (Acanthurus
achilles).They both
began to bully my regal angelfish as they grew larger than it.Furthermore, you should definitely not mix a regal angelfish
with large angels of the genera Pomacanthus
and Holacanthus.These fish will definitely bully a regal angelfish.Even some of the more aggressive Centropyge
species (e.g., C. joculator, C.
acanthops, and C. aurantonota) will harass small regal angels if
they are existing residents of the aquarium.
Regal angels are more
sensitive to deteriorating water conditions than many other marine
fish but they don’t have special requirements as far as water
parameters.A
reef-type aquarium is ideal because it provides the rocky reef
structure that the fish requires to feel secure.Combining regal angelfish with corals is always a risky
proposition, but they are generally “safer” than most other
Pomacanthids and even most Centropyge
species.If a regal
is going to pick on corals, it is usually confined to a particular
coral or type of coral.The
decision then becomes which do you want more, the regal or the
coral.Regals
generally ignore Acropora
species but have been reported to pick on certain large-polyped
stony corals such as Trachyphyllia
or certain soft coral such as Xenia.Regal angels that are well-fed are less likely to explore the
aquarium for alternate sources of food.
Red
nori macroalgae is a good source of nutrition and natural
coloring agents for regal angelfish.
Regal angelfish (Pyglopites
diacanthus) can be mixed with corals and clams, but there
is always some risk.The
author’s regal angelfish has not bothered any desirable
invertebrates in his 500 gallon reef aquarium.
The key to success with
regal angelfish is starting with a healthy specimen.Unhealthy fish rarely recover in captivity.Juvenile specimens, in the range of 7 to 10 cm (3 to 4
inches), are ideal because they acclimate more easily than adult
fish and they’re sturdier than smaller fish.Tiny regals, as seen in recent imports from Fiji, can be
difficult to feed and tend to be shyer than larger individuals.The high metabolism and low fat reserves in very small fish
leaves no margin for error while acclimating to life in captivity.Even a short period of starvation can result in death.Large regal angels are also a bad bet.They don’t ship well and generally have a more difficult
time adjusting to prepared foods.
Regal angelfish
originating from the Red Sea and Indian Ocean are generally
superior to Indo-Pacific imports.In addition, they have more attractive coloration.It may be that the natural diet of Indo-Pacific specimens
is more difficult to duplicate or it may simply be that Indian
Ocean/Red Sea fish are collected and handled better than fish
coming out of Indonesia and the Philippines.
Never
buy a regal angelfish that will not eat.A healthy regal angelfish will usually eat live brine
shrimp or frozen mysis shrimp.Also avoid fish that are not swimming normally.Regal angelfish are naturally cautious fish and may hide
when you approach, but they should not be hovering near the
surface of the aquarium, breathing heavy, twitching or scratching.These are possible signs of parasitic or bacterial
infections.
Observe a prospective
regal angelfish “head-on” for signs of prolonged starvation.“Pinching” in the dorsal musculature (the region above
and behind the head) indicates that the fish is malnourished.They rarely recover from this state, even if now eating.
Avoid “bargain” regal
angelfish.Healthy Red Sea specimens that have been quarantined and
conditioned are not inexpensive fish, but they’re worth seeking
out.Better
retailers, such as Marine Center (http://www.flash.net/~rarefish/)
pre-treat and condition their regal angelfish to eat prepared
foods, and these fish are worth the small premium associated with
that service.
Given
adequate space and proper nutrition, it’s possible to
maintain the regal angelfish (Pyglopites
diacanthus) in all its glorious colors for many years.This one resides in the author’s 500 gallon reef
aquarium
