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Premnas
biaculateus (Maroon Clownfish)
Photo of a Maroon clownfish (Premnas
biaculateus) with a Cleaner Wrasse (Labroides dimidiatus).
"Oh my gosh! That
plant is eating that fish!" You know it's got to be a
neophyte observing a member of the clown or anemonefishes
SubFamily Amphiprionae, in the damselfishes family (Pomacentridae),
cavorting amongst the tentacles of a host anemone.
Prized for their bold
and bright color patterns, comical behavior, and ability to
thrive in captivity, there is much disinformation regarding
the selection and care of clown-anemone fishes. This
sub-Section attempts to present straight-forward information
on how to be successful with the damsels we call clowns.
Classification:
Is still a jumble. There
are about twenty six valid species, all but one in the genus Amphiprion;
with one member in the genus Premnas. These are further
lumpable into four "complexes". Ho-boy.
Unfortunately for
aquarists, anemonefishes are very frequently misidentified in
our trade/hobby, and share the same four or five common names.
Notable species, grouped by similar appearances include:
1) Multiple-striped
orange to tan to brown clowns: Amphiprion ocellaris,
variously sold as "percula" clowns from whom they
can usually be distinquished by the presence of thick black
bordering on the white bars of the "true" perculas, .A.
percula. Other similarly marked species include A.
clarkii, A. bicinctus, A. chrysopterus and
the rare A. sebae ("C-bay"), more often than
not a misidentified Clarkii clown. Oh yes, and the
tear-shaped, saddle-back clown, A. polymnus, the
Wide-Band Anemonefish, A. latezonatus.
For a workable key to
species see Allen, 1974 or 1979. I bear full
blame/responsibility for the above version of unnatural
western grouping of these fishes.Most authors group
anemonefishes as a subfamily, Pomacentrinae of the
damselfish family, Pomacentridae. They differ from the damsels
in having fewer dorsal spines and structural markings on the
margins of some of the head bones and other even more
obscure minor tendencies and differences.
Oh yes; and one other
salient characteristic: their lifelong mutualistic symbiotic
relations with certain species of anemones. This is an
obligate (absolutely necessary) arrangement in the wild; they
are never found without anemones. Without their protection and
shelter, clownfishes are quickly consumed.
Distribution:
Distribution: Anemonefishes are found throughout the Western
Indo-Pacific. Most are collected from the Phillippines. None
are found in Hawaii.
Selection:
Of clownfishes should
be a breeze and a pleasure. In the wild they are abundant and
easy to capture. All are found in intimate contact with
certain species of sea anemones and are easily netted off
their "homes" using hand nets, a cup of just by bare
hand. None are cyanided; that poison costs money, and is
unnecessary.
Sadly, many
clownfishes meet an early end through rough handling,
transport and difficulties in general acclimation. There are
estimates of some ninety percent mortality en route from
capture to distributors and of those remaining, another nine
tenths perishing before even reaching the retailer's tanks.
Why? Another cyanide
scapegoat? No, in a word, stress.
Being rudely pulled from the
"loving arms" of your anemone host(maybe instead of
something sounding like "an enemy" we should call
them "an ally"), losing the advantage of
"cleaning" by your anemone and interaction with
members of your species and possibly family, take their toll.
Add to this, chemical and physical
insults of polluted holding-water, gill and body
"burn" from ammonia build-up in a tiny shipping bag
and the trauma of co-mingling with strange and exotic species
in a distant clear-sided container and it's a wonder any
survive.
So, what can you do? Be a good (=
informed & conscientious) consumer!
First of all, buy tank-bred and
raised stock if possible. Percula (ocellaris),
sebae (clarkii) and tomato (frenatus) clowns
are produced in
commercial numbers. These may be initially smaller and
less-colorful than wild-caught specimens; but they do live.
Aquarium-conditioned
specimens, tank-raised or not, should be well-fleshed,
especially along the back; alert, feeding with no whitish
marks on their bodies of fins. If the fish offered are
lethargic, hanging out in the corner with drooping, clamped
fins, not feeding or have whitish markings....DO NOT BUY
THEM! In fact, don't buy a fish from a system with any
other fish in it displaying these symptoms.
Clowns should be very
alert, colorful and fat! They should swim with a
wagging motion, and will usually dart to the back of the tank
at your first approach, then come eagerly back to the front to
look at you.
Size:
Size: juveniles to sub-adults adapt much better to captive
conditions. Some clowns, like A. ocellaris, may reach
up to five inches in the wild. Optimum minimum small sizes for
all species are about one inch for wild and three-quarter inch
for tank-reared.
Buying for Breeding:
Buying for Breeding: Stock purchased for breeding should be as
for most species; buy and raise a group of smaller-than-mature
individuals and allow them to pair off. Several species can be
sexed externally when large enough, as the females are much
heavier-bodied and/or differently colored. Usually when you
get two clowns, if you buy one larger than the other, the
larger one will turn more aggressive and become the female.
For a discussion on structural and color differences and
sex-changing (!) see Hoff 1984.
Environmental:
Like many organisms
living in close association with invertebrates, anemonefishes
are sensitive to similar chemical and physical conditions and
changes.
Acclimating/cleansing
dips should be used and be of short durationAcclimating/cleansing
dips should be used and be of short duration. Use freshwater
with very little or no formalin, copper, malachite, et al.. A
dip, not an extended bath.
System temperatures
should be in the mid to high seventies (F.) with specific
gravities of about 1.023.
High water quality,
especially keeping low levels of metabolites (proteins,
albumen, phenols, nitrogenous compounds, etc.) are advised.
Suitable bio-filtration, protein skimming with or without
ozone & frequent partial water changes are the rule.
Behavior:Territoriality:
Anenomefishes can be
overtly territorial, in particular where any threat to their
host anemone is concerned. It is suggested that they be
introduced with their host anemone after other fish
tankmates, or provided with their own system. If your clown
fish are very large and you want to try adding new specimens;
disturbing/re-arranging the physical environment,
extra-feeding and a watchful eye for problems are advised.
Most other species of fishes are left alone as long as they
are previously established, larger or more aggressive, and do
not bother the Clownfish's anemone or come too close while the
clown's are breeding. Anemonefish can and will attack you and
draw blood if so inclined.
Large non-paired adults
generally do fight in all but the
largest aquaria.
Likewise, mixing species of all but juvenile sizes is chaotic.
Keep them in separate systems.
To reiterate; aggression
can be intense amongst and between species of Anemonefishes.
They lock jaws and "bite" each other cichlid-like.
To reduce agonistic behavior, provide adequate size quarters,
a number of anemones, be leery of mixing sizes and sexes and
restrict your collection per tank!. If you want to try mixing
adult species, make sure each pair has a large anemone, so
they won't fight over anemones. Breeder pairs of some species
are kept in ten to twenty gallon systems commercially; yours
should be much larger.
Symbiosis with Anemones:
Do they really need an
anemone? No, none of them; all have been kept and a few
species spawned sans coelenterate; but some species do better
then other's in an anemone's absence. A. melanopus, A.
frenatus and A. biaculeatus are my top three for toughing
it out without their "pals". However, chances of
keeping and breeding anenomefishes in captivity is greatly
improved in the presence of host anemones.
The mutually beneficial
behavior of clowns and anemones has been well documented and
popularized (see Thomas 1978), as has methods of selecting
healthy symbiotic anemones. We'd like to reinforce a few
points:
If practical, buy an
anemone of known symbiotic potential; i.e. one that's
displayed with symbiotic clowns, and if possible, buy one
with the symbiotic fish desired. Most stores will sell you
clowns and anemones that are already living together.
Many species of anemones
are unsuitable. (e.g. Condylactis species from Florida,
Atlantic carpets). Your clownfish may not easily
chemically/physically introduce/communicate/consort with their
intended host(s). They may even (gasp!) be consumed by, not
with, them!
Some anemonefish species
and individuals of larger sizes do well without anemones,
though it has been speculated that they play an important role
in removing external parasites besides providing shelter and
protection from predators.
Breeding:
Has been a hot topic
& covered well elsewhere (Goldstein 1982, Young 1984,
Branowski 1985, Lindner 1986). Suffice it here to write that
anemonefishes breed a lot like substrate-spawning neo-tropical
cichlids; by cleaning a rocky smooth surface next to or under
the base of their host anemone. They deposit eggs, mouth,
guard and fan them. When they become free-swimming, the fry
are dispersed like planktonic zooplankters.
In captivity their
planktonic fry may be fed exclusively on marine rotifers which
are easily hatched from eggs. They reproduce throughout the
year, laying a few hundred to a few thousand eggs about once a
month.
Many species have been
spawned and reared in captivity. A. ocellaris, A.
frenatus and A. perideraion are most commonly
found.
Sound Production :
Yes, they are noisy!
Clicks and grunts of various types and apparent function have
been detailed and is a rich research area. Listen when they
are defending their anemone or spawning.
Feeding:
Is not problematical
with these fishes. They readily consume dry, prepared,
freeze-dried, frozen, live and fresh foods. In the oceans,
most rely mainly on zooplankton, with some considerable algal
matter found in stomach contents analysis studies. It is
suggested that a variety of prepared fresh foods, including
vegetable matter be offered on a twice-daily basis. Watch them
eat, they will share their food with their anemone.
Diseases:
Anemonefishes are
susceptible to many environmental and infectious diseases, and
are hosts to numerous species of ectoparasites incuding
isopods, monogenetic trematodes (flukes) tapeworms and
roundworms.
Most fish are lost
either through the initial collection to end user process, or
the first losses of infection, or poor water quality
maintenance, or even more regrettably, "treatment".
Particularly problematical with these species are initial
situations where specimens are compromised/debilitated
extensively and rapidly "breaking down" (see
photos). This combination bacterial, fungal, protozoan mess,
so common in newly imported clownfish might be termed "new
anemonefish syndrome". Left unchecked and not, this
"syndrome" results in mass mortalities of captured
specimens. Among the most often identified pathogens, the
algae Oodinium and the protozoans, Cryptocaryon
and Brooklynella are common parasites of newly-arrived
anemonefishes.
Treatment: Prevention,
as usual, is the rule.
1) Pick out reasonable
stock as detailed in the selection of this article.
2) Do a brief freshwater
dip to remove some/most external grunge (a scientific term).
3) Quarantine your new
stock if at all possible/practical with or without their
anemone for a couple of weeks. Using a mild bacterial
medication is suggested; Maracyn II (tm) is excellent.
4) Introduce them to
their new viable, permanent aquarium. After acclimation, add a
"slime-coat" water conditioner.
Note: If you can't
procure quarantine quarters, ask your retailer to hold your
charges for you on deposit.
If you find yourself
with clownfish with an apparent infection/infestation
that seems to necessitate treatment:
1) Check and
adjust your water quality. Most "disease"
conditions of captive aquatic systems are a result of poor
water or system quality. Do not just start pouring a
therapeutic into your tank(s). Often, moving the clown's to a
different system effects a fast "cure".
2) After quickly
doing whatever you can to "re-center" your system,
consider further treatments in the following order of
priority:
A) Biological: Add
a symbiotic anemone if you don't have one or move the fish(es)
to a system with one. Add a cleaner; a suitable Labroides
wrasse, cleaner goby, cleaner shrimp; they work.
B) Physical: Lower
your specific gravity. Even with most invertebrates,
dropping the specific gravity a few thousandths per day to
1.018-1.019 will not do permanent damage and may shift the
balance of favorable conditions to your fishes.
C) Chemicals:
Last and least. Be careful. Clown
fish are like "canaries in a cave". They tend to be
sensitive to the same toxins as their host actinarians
(anemones). Copper, other metal salts, organic or metallic
dyes, furan compounds, and organophosphate pesticides all have
deleterious to disastrous effects. These substances in various
formulations, comprise most of the "medicine
treatments" available and used in our aquatics interest.
They do have some limited, appropriate applications in bare
marine treatment tanks. 'Nuff said?
These chemical
therapeutics are dangerous and unnecessary with clownfishes.
"Experiment" with them only as a last resort.
Predators:
Allen (1974) lists the
following possible aquarium fish families as potential
predators: Can you name them?
Muraenidae Moray eels
Synodontidae
Lizardfishes
Serranidae Groupers,
Basses
Cirrhitidae Hawkfishes
Lutjanidae Snappers
Scorpaenidae
Scorpionfishes, Lionfishes, Turkeyfishes
Actually any tankmate
with a large enough mouth may eat your anemonefish, especially
in the absence of a symbiotic anemone. Be forewarned: as their
family members, the rest of the damsels, clownfish are common
forage fishes.
Summary:
Clownfishes have
everything going for them as aquarium specimens. They're
hardy, behaviourally interesting, colorful, do well on all
types of foods, & if you start with healthy specimens and
meet their habitat requirements, they're human-responsive and
long-lived.
With
the permission of Robert (Bob) Fenner webmaster
of WetWebMedia
(bobfenner@aol.com) |