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Scarus
taeniopterus (Princess Parrot)
What
is it that soars like a parakeet, is as beautifully marked as
any butterfly, has a "beak" like a macaw and is a
major source of fine coral sand? Give up? It's the
Parrotfishes, family Scaridae.
This
group would seem to have everything going for it as far as
desirability to marine aquarists; many are spectacularly
colorful, they have almost comical fusiform-torpedo body
shapes, and are numerous and easy to catch (at night) as they
lay sleeping with or without their fish-made mucus cocoons.
Their
only downside, and it's a big one, is that scarids rarely live
for anytime in captivity(!); either starving to death for
reasons that will become obvious, or "stressing" out
to extremes due to other rigors of captivity. Let's cover some
of the science and captive maintenance notes of this group to
gain appreciation and offer insights to parrotfish selection
and care.
Natural History:
Scarids
are all marine, mainly tropical in the Atlantic, Indian and
Pacific Oceans. They have non-protractile mouths with
coalesced jaw teeth resembling a parrot's beak. Like the
related wrasses they sport large cycloid scales, large, thick
caudal peduncles (the part of the body right before the tail
fin) and broadly truncate (square) caudal fins. According to
Nelson (1994) there are currently nine genera with eighty
three reliably described species. Due to radical changes in
color and markings consequent with sexual stage developments
there are many nominal, mis-identified species. I'll try to
make this clearer under the "sex and the single
parrotfish" heading below.
Parrotfishes
are closely related to the popular aquarium fish family
Labridae, the wrasses. They are collective members of the
Sub-Order Labroidei in the largest living Order of fishes, the
Perciformes. An interesting higher classification note here
for those so inclined; Nelson (94) recognizes the cichlids,
surfperches (family Embiotocidae) and damselfishes (Pomacentridae)
as part of the Labroidei as well. See Joe's references in the
third edition for further discussion for more.
Species
of Use/Disuse:
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Catostomus carolinus
(Valenciennes
1840), Caroline's Parrotfish.
The most wide-ranging
species of the family, Indo-Pacific,
eastern coast of
Africa to tropical eastern Pacific. To eighteen inches
in length. Feeds mainly on benthic algae and seagrasses.
Pictured: a secondary male in the Cooks.
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Cetoscarus bicolor
(Ruppell
1829), the Bicolor Parrotfish. Likely the most commonly
sold species of Parrotfish in the aquarium interest...
almost exclusively as juveniles. Indo-Pacific, Red Sea
to Tuamotus. To three feet in length (not a misprint).
Pictured: Adult male in the Cooks at right, supermale in
the Maldives at very top, aquarium juvenile and female
and male in the Red Sea below
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Chlorurus sordidus
(Forsskal
1775), the Daisy Parrotfish. Indo-Pacific, Red Sea to
Hawai'i. Mainly feeds on benthic algae. To sixteen
inches overall length. These images from Hawai'i and the
Cook Islands... of terminal males. A highly variably
colored species.
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Scarus altipinnis (Steindachner
1879), the Filament-Finned Parrotfish. To two feet in
length. Pacific Ocean. This supermale and juvenile
photographed in the Cooks.
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Foods/Feeding/Nutrition:
A
common misunderstanding with this group is what they eat. They
rarely feed on actual live corals tissue, but stomach-contents
analyses have shown they do derive most of their nourishment
from scraping organisms, mainly algae, living in and amongst
dead coral substrates. Please see the accompanying image of
how this is accomplished. Yes, they do chew off the
live and dead heads of corals in gathering this material.
Some
aquaristic writers have listed snails, crustaceans, shellfish
and urchins as real and potential food items for captive care.
Maybe a successful long-term approach to feeding these species
might take the form of algae etc. mashed food being somehow
applied to coral skeletons...
Aquariogenic
Stress:
Okay,
I'll come clean; I made up the word aquariogenic. I'm looking
for a term to describe the imposed consequences of captive
care in fish tanks; effects that are different in kind or
extreme due to aquarium versus wild conditions. You know what
we're getting at here; some species, sizes, sexes, individuals
do much better in aquaria than others.
One
way of discerning which varieites may be better for aquaria is
observing them in their natural environs. Watching our aquatic
charges on the reef yields much valuable behavioral
information. Parrots are wide-ranging, sometimes covering
several hundred square meters in the course of one scuba-dive
observation period. This wide travel may be a matter of
searching through enough necessary foraging space; allowing
favorable foodstuffs to recover.
Obviously,
in captivity such large areas are unavailable and apparently
exert a dunning effect of parrotfish vitality. They go from
extreme extro- to intro-verts, settled on the tank bottom,
whereas parrotfishes are in almost constant search/eating mode
on the reef during the day, stopping, "sleeping"
only at night.
Other
Items of Interest:
Places
I've been to in the world (e.g. Tahiti, Baja Mexico) offer
parrotfishes as regular table fare (see the picture of
split-dried parrots for sale in Lombok, Indonesia). At some
localities (the leeward side of some Caribbean Islands) people
eat them seasonally; in other areas (parts of the
Indo-Pacific) parrots are carefully excluded as being a source
of ciguatera, food-fish poisoning. Scarid toxicity appears to
be a matter of bioaccumulation of poisonous algal proteins.
How
much substrate do you want to have in your marine system? In
the course of breaking off, scraping and pharyngeal grinding
coral skeletal material Parrotfishes excrete large quantities,
veritable showers of coral sand. I'd seriously venture that
the Parrotfishes of the world egest several thousands of tons
of such material a day. Amazing, eh?
Sex
and the Single Parrotfish: Like the wrasses, most parrots have
proven to be protogynous hermaphrodites (both functional
sexes, females turning into males); but as they say on late
night T.V. advertisements, "But wait, there's more".
Imagine you're looking at all the parrotfishes on Earth. You
have some notion of what a "species concept" is all
about and structurally and genetically and biochemically and
any-other-else-ally there are distinct (sort of)
"types" of parrotfishes seperate from other
"types". But color and marking-wise within these
species-types there is some widely differing
"sub-types". Well, it turns out there are about
four, five of these per species.
Now
follow me here; there's 1) undifferentiated immature
individuals, 2) one's that have developed into females, 3)
those that have gone through being females and are now males,
4) some that are/were "just" males, and finally, 5)
Super males, typically larger, most brightly colored
"alpha" types. Though unlike some wrasse species,
they don't' change much morphologically (structurally) with
sex switching, parrots frequently have striking color
differences with different age, social status and gender.
Large, colorful supermales must be seen in person in the wild
to be fully appreciated.
Whew,
easy huh? Now you can see where the confusion has come from in
accurately detailing whose who species-wise.
How
do we know all this is so? Some clever weird-science
researchers have shot up Parrotfishes with sexual hormones and
cataloged their subsequent changes. Ho-boy. That and bunches
of diver reconnaissance.
Selection:
If
you're determined to try a member of this family here are my
suggestions:
1)
Engage as large a system as you can; a hundred gallons plus.
2)
The more established the tank, that is, with mature algae
growth, the better.
3)
Buy a small species; (some get to over three feet in length),
at a small size; four to six inches. Three smaller favorites
are the queen parrot, Scarus vetula, the spotlight
parrot, Sparisoma viride and the bicolor parrotfish Cetoscarus
(Bulbometopon) bicolor.
4) Do
try to get your specimen as fresh from the sea as possible.
The longer the fish stays in transit from the collector,
wholesaler, and retailer to you the worse. It's just getting
more starved and stressed.
5)
Offer a variety of homemade and/or prepared food items along
with sufficient fresh material and monitor their acceptance.
Open, but leave krill, shrimp, clams, mussels and the like in
their shell for calcium intake and tooth wear. Try offering
these foods at the "top" of your habitat (coral,
rock); this is where parrots feed on the reef.
6)
Provide vigorous circulation and filtration as scarids are
avid eaters and prodigious producers of body mucus, especially
the species that spin their nightly sleep cocoons; which
brings up...
7)
Make preparation for a suitable hiding and sleeping space; a
nice coral or base rock cave with low illumination.
8)
Just get one. They don't get lonely, but may fight and do get
big. Usually, you'll end up with a colorful male.
9)
Because of their non-competitive nature don't mix with
aggressive, food-greedy species like large basses and large
damsels.
A
Conclusion:
Most
species and individual Parrotfishes are difficult if
not impossible to keep for very long under "typical"
(i.e. small) aquarium conditions. In the wild they are found
continuously roving, grazing stony corals, gnawing and
scraping at these dead coral substrates for their algal
growth, and generating copious amounts of fine coral sand.
In
low-volume tanks they waste away, skulking in a dark corner
possibly dreaming of happier days scouring the reefs. My
advice is to instead seek out and enjoy one of the many hardy,
related wrasses. Several varieties of these fare very well in
marine aquaria. Leave the parrots to cruise their coral palms,
making us more sand.
References/Further
Reading:
Burgess,
Warren E., 1981, 82. Parrots of the Sea. Pt. I, II. Tropical
Fish Hobbyist, 12/81, 12/82.
Nelson,
Joseph S., 1994. Fish of the World, 3rd Ed.. Wiley and Sons,
N.Y.
Spies, Gunther, 1990. Sand Factories- the Parrotfishes.
Tropical Fish Hobbyist, 4/90.
With
the permission of Robert (Bob) Fenner webmaster of WetWebMedia
(bobfenner@aol.com)
Photo by Mike Iannibeli
(with permission) |