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Conspicuous growth of a captive Pacific species of brain
coral on sedimentary-formed Atlantic live rock. Photo
by Allan Skulicz.
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In the June 2002 issue, I
detailed some fundamental methodologies for propagating corals,
and so it stands to reason that an article on methods for
securing the resulting divisions follows suit. For many ambitious
coral farmers, propagating corals can be summed up with a
flip utterance, "Saw it, fragged it
licked the
salt off my hands!" Well
that, of course, is a
ridiculous statement. I would never personally condone such
an unsanitary act without lemon wedges and a fifth of top
shelf tequila. But, enough about how I personally propagate
coral. Here, I intend to proffer advice and wisdom to aquarists
on some of the most popular methods for attaching fragments
of coral to a hard substrate.
Methods for securing hard
or soft coral are likely to fall within one of the following
categories:
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Tethering:
plastic ties, rubber bands, wire or thread, stitches,
suspension
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Adhering:
cyanoacrylate/super glue
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Capturing:
cementing and epoxying
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Containing:
collars, cups, netting, tubes and pipe, rock crevices
and corrals
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Impaling:
drilling, pegging, spearing
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Natural Settlement:
on live rock, sand, ceramic tiles/glass, in rubble
troughs, etc.
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Tying,
Banding and Stitching Coral
Tethering corals by tying,
banding or stitching might be the most effective method for
securing the broadest range of propagated hard or soft corals
with reasonable to very good rates of success. It almost assures
sound mooring of coral divisions the first time. In contrast,
glues and epoxies, for example, may require occasional to
frequent re-application (as with heavily mucous species and
others with more fickle changes in their hydrated mass from
polyp cycles). Nylon thread (or monofilament fishing line),
natural rubber bands and plastic cable ties (AKA "zip
ties") are the most common fasteners. Indeed, there are
many imaginative varieties of fasteners applied to coral by
farming aquarists. Even when aesthetically unattractive, fasteners
are usually a temporary solution while waiting for subsequent
natural attachment of a new fragment. They will be overgrown
or unnecessary (and can be removed) after a modest wait for
new coral tissue to anchor the division.
Of all the many ways listed
above (and beyond) for fixing newly fragmented divisions,
stitching with plastic thread or wire is one of the
fastest, safest and surest ways of securing corals. Most soft
coral that are fragmented can be stitched with a needle and
plastic thread with little effort or time. If you are willing
to drill a small thread hole in scleractinian skeletal mass,
many stony corals can be fixed quite assuredly in like fashion
(and it gives you another reason to get out the electric rotary
tool!). Corals stitched with one or two threads through the
stalk and tied off to a hard piece of rock or rubble are surely
secured. They cannot be lost to volume changes of the fragment
due to polyp expansion and contraction. Neither can they be
easily displaced by water currents, or by the activities of
fish and motile invertebrates. Indeed, a soft coral fragment
may shrink away from glue or epoxy. Likewise, it can be carried
by currents out of and away from collars, cups and troughs,
but a stitch through the trunk of an octocoral provides a
secure anchorage. This method may be done as quickly or faster
than any other method of attachment for coral frags, and I
highly recommend it for heavily mucous species that
will not tolerate either excessive handling or widely constrictive
fasteners. Indeed, stitching is one of the surest ways to
attach "difficult" settling species such as green
and yellow "finger and toadstool leathers", Sarcophyton
and Sinularia, as well as Klyxum (AKA "Colt"
coral
formerly Alcyonium), Cladiella and
Neptheids. Common, branching soft corals in general respond
very well to stitching.
Using a needle, fine plastic
thread (nylon sewing thread or clean fishing line) is readily
available to most any aquarist, easily applied and has he
added benefit of affording reduced handling time of corals.
Fastening can be conducted under water and requires no additional
preparatory steps. The pictures below are hardly instructional;
the act of sewing a coral to a piece of rock is rather self-explanatory.
Instead they are proffered for encouragement that the application
of a stitch to fasten a coral to a rock really is as straightforward
as it seems. The photos also serve as a reminder why heavily
mucous species of coral are best served by stitching. Please
note the heavily viscous mucus issued from this soft coral
in mere seconds after the imposed fragmentation! Clearly,
this animal could not be handled easily without an instrument
like tweezers. Such heavily mucous species obviously cannot
be superglued or epoxied to a dry substrate. Even if they
could, I propose that when a brief stitch is applied so quickly
and with little intrusion, it is a preferred method of attaching
soft corals to hard substrates.
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When handling heavily mucous species, like this Xenia,
it is very important to avoid contacting tissue with
bare hands. Excessive handling stimulates the production
of mucus which increases the proliferation of bacteria
that may become pathogenic.
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While a discreet stitch is
the least invasive method for tethering a fragmented coral,
elastic natural rubber bands are also effective fasteners
too. They are used to hold a coral division in place against
a hard substrate ("live rock", corallum, ceramic,
plastic, aragonite, etc.) while waiting for natural attachment
of the division. A healthy coral will usually generate sufficient
new tissue within a few weeks to anchor the specimen. A natural
rubber band will rather conveniently dissolve in seawater
in less than a month, sparing the appreciative farming aquarist
the need to remove it. The elasticity of rubber bands allows
them to ride the fluctuating volume of coral tissue through
inflating and deflating polyp cycles before the division becomes
firmly anchored. Some aquarists like to sandwich a fragment
between two small pieces of substrate, while others simply
band a division against a single piece of rubble or like medium.
Sandwiched divisions need to be oriented in such a manner
as to receive maximum water flow and light, while still being
held securely. An appropriately sized thin rubber band
will just barely constrict a fragment to prevent dislocation
with the currents. Thicker bands deprive a division of normal
diffusive functions over a greater surface area (under the
band) and slightly increase mortality and infection from anoxia
and increased mucus. An elastic band that is too tight will
sharply constrict a fragment and may actually cut through
a division successfully before the fragment has a chance to
attach. This means that two fragments instead of one will
be lost, blowing around an aquarium with the currents! Unpigmented,
natural rubber bands are harmless and non-toxic. They may
not be pretty, but they are inexpensive, easy to apply and
remove quickly and may be used on a majority of popular hard
and soft corals with reasonable to good success for attachment.
In grossly generalized terms, SPS and weakly mucous soft corals
respond quite favorably to such banding while LPS, zoantharians
and heavily mucous soft corals do not.
Scleractinian species, and
many octocorals, are more suitably affixed to a hard substrate
by simply tying them to it with non-elastic fasteners
like plastic cable/"zip" ties or nylon filament.
This is due to the unyielding rigidity of the scleractinian's
corallum that prevents any displacement of the animal under
an inflexible tie. Soft corals suitable for tying are those
not quickly changeable in volume from "hydration"/polyp
expansion and usually have large, densely fused spicules which
lend necessary rigidity to their form, for example, Nepthyigorgia
"chili corals", some Sinularia and Dendronephthya.
Even non-scleractinians such as Heliopora and Millepora
respond favorably to this simple method of securing a
division and can quickly overgrow a thread to look quite natural
in form after a short time. As with rubber bands, because
of the reasons listed above, thinner is better when used to
simply tie down a fragmented division of coral. Plastic cable
ties are also used to facilitate a compound attachment, in
some octocorals where the tie is used to slowly constrict
and pinch off a soft coral division, which attaches to the
fastener before the separation is complete. After the branchlet
finally drops, the attached fastener serves, at the very least,
as a handle to avoid touching the new division. It may be
attached to a permanent substrate by gluing to or threading
the tie through a hard surface, or simply weighting down a
tethered fragment. Cable ties are effective but cumbersome
and unsightly for most SPS corals. Fine nylon thread or monofilament
line is likely to be more aesthetically discreet. Cable ties
may be quite useful, however, to secure LPS corals by drilling
an inconspicuous region of the skeleton to thread plastic
ties through like stitching rockwork. As with the use of rubber
bands, temporarily fastening coral by tying it with plastic
straps/ties or thread may not be pretty, but it is effective.
Adhering Corals with Cyanoacrylate Glue
Glues and epoxies are marketed
heavily and are popularly employed in coral propagation, but
not all truly adhere corals to a medium. Adhesion is
the formation of a bond between two surfaces: "sticking
together", one might say. Cyanoacrylate glue is one of
the few "glues" in coral propagation that properly
fits this description. In contrast, epoxies, cements and hot
glues more accurately capture corals by pouring in
form (or being molded in form) around a specimen and then
curing hard to hold a fragment in place. They do not, however,
actually "stick" to living tissue in a proper bond
like cyanoacrylate glue can.
Cyanoacrylate (superglue)
has been heralded like the eighth wonder of the world for
attaching coral categorically. Many aquarists read in aquarium
literature and hear about the convenience of using this product,
but experience with it is often met with frustration, disappointment
and a lost coral fragment blowing around the aquarium. Quite
frankly, I do not understand or agree with all of the hubbub
surrounding this technique especially as it pertains to species
other than SPS scleractinians. I have handled many thousands
of fragmented divisions of soft and hard coral (secured with
various techniques), and find the process of gluing with cyanoacrylate
to be tedious, at best, for many popular coral species. I
have listened to more aquarists than not complain through
the years about difficulties with utilizing this technique
that really cannot be attributed to procedural faults. Defenders
maintain that there is a very specific protocol (that is ironically
quite variable among the defenders) for attaching soft corals
with cyanoacrylate glue. Please forgive me, but I am just
not willing to buy into the hype of a ten-step procedure for
getting super glue to set that involves a Tibetan Sherpa,
a stick of chewing gum and a roll of duct tape. Indeed, I
am exaggerating here for the purpose of a bit of humor, but
still I mean to relate that the application of cyanoacrylate
glues to living coral is often misunderstood or misapplied
by aquarists. The time required to apply such glue is no faster
than a simple elastic band or tie/stitch and it certainly
is not as reliable (where a stitch works the first time, every
time
cyanoacrylate may need to be re-applied). As super
as it may be around the household, it is not a universal adhesive
for most or even many corals. Cyanoacrylate glue can indeed
be very useful for some coral like SPS species,
but it is ultimately very challenging to employ with many
other corals. It seems to work best with surfaces (living
or not) that can easily be patted dry and handled out of water
for some time without suffering or secreting much mucus, such
as the broken edge and exposed corallum of stony corals, the
woody gorgonin stem of a gorgonian and the rough surfaces
of many "leather" corals. These are very fine places
to which one may easily and successfully bond cyanoacrylate
glue to another surface. One of my favorite applications of
cyanoacrylate glue is upon the underside of stoloniferous
corals ("mat" formed like Star polyps) for setting
sheets of living coral in place upon the aquarium's vertical
back and side walls (temporarily drop water level to do this).
Other artifacts of the aquarium system like plumbing/pipes
and overflow wells may be covered in like kind with a living
veil of coral by cyanoacrylate glue. Yet, other corals still,
like individual zoantharians (button polyps or mushrooms anemones)
and "slimy"/mucous corals like "Colt"
coral (Klyxum), are very challenging to secure anywhere
with cyanoacrylate and are best anchored by other means. With
the intention of trying to keep this article shorter than
the preamble to the Constitution <G>, let me direct
aquarists interested in learning more about the various subtleties
for properly applying cyanoacrylate glue abroad onto the internet
and more specifically to a wonderful site for aquarists: GARF.
For aquarists not familiar with the work of Leroy and Sally
Jo Headlee, their site is filled with an enormous amount of
very useful and instructional content in articles, images
and video on a wide range of topics embracing reef aquarium
science. Know that there are likely more than a few ways to
successfully apply cyanoacrylate glue to live coral for settlement.
Capturing Fragments with Cement and Epoxy
As mentioned above, epoxies,
cements and hot glues are used primarily to capture
coral within the hardened (cured) constraints of a poured
or molded form. Some popular products include two-part underwater
epoxy, dental cement, hydraulic cement (expanding/fast-setting),
and even common Portland cement. They do not actually adhere
to coral tissue, although this does not make them any gentler
on living tissue. Their chemical curing processes, while hardening,
may be irritating to some coral and fish. By and large they
are safe to use, but some fish and coral have demonstrated
severe and even rare fatal reactions to these applications
in seawater. For most aquarists practicing good aquarium husbandry,
such as water exchanges, protein skimming and good chemical
filtration especially after coral propagating events,
problems will be very rare with such products. Naturally,
anecdotal reports about deleterious reactions do not oblige
manufacturers to disclose warnings with products or packaging.
Aquarists with small-scaled and scaleless fishes (firefish,
mandarins, lionfish, etc. as well as sharks, skates and rays)
should already be conscientious of the sensitivities of such
fishes overall to medications, metals, additives, etcetera
in their charge, and demonstrate due preparedness in aquarium
husbandry. Disclaimer aside, securing corals to a substrate
with cement and epoxies can be quite useful and safe in many
applications.
I have used underwater epoxy
and cement in various applications and find it to be quite
useful for many aspects of aquariology such as securing rock,
or coral. It is especially helpful with coral and structures
in need of a stronger union as with larger divisions of coral
or those to be anchored in areas of dynamic water flow. Indeed,
such cements are appropriate for the more substantial needs
of gluing large rocks and corals, and as such have their place
in the hobby. My only reservation for using such products
on a larger scale than home aquarist or backyard/basement
coral farmer is that the epoxies are too expensive and the
cements are too labor-intensive to be useful in commercial
endeavors.
The application of each product
varies, but in gross terms, a portion of cement or epoxy is
necessarily forced into cracks and crevices on an irregular
surface such as live rock. Smooth surfaces are less likely
to form good bonds once cured. By penetrating into irregular
surfaces, these products can harden to form very strong, finger
like grips on substrates. Before curing, a division of coral
is pressed into the medium with some of the cement or epoxy
molded up and around the fragment if possible to help capture/curb
it. The hardening time varies with each product, but is generally
less than fifteen minutes and can often be completed under
water. Full curing may take up to 48 hours. To prevent any
deleterious curing byproducts from entering the "home"
tank, it may be helpful to allow the curing to complete in
a remote holding vessel, such as like a water bath.
Containing Corals with Natural and Artificial Barriers
Securing corals by methods
of containment can involve positioning many different
items to create a barrier. Aquarists have learned to become
quite inventive by necessity while pioneering coral farming
techniques. Common materials for this purpose may include:
PVC collars/pipe segments, plastic cups, shallow glass jars,
plastic or nylon netting (like rain gutter guard, bridal veil,
fruit mesh, etc.), clear plastic tubes, floral picks, and
even holes drilled in rock or other substrates. Some aquarists
arrange small pieces of scleractinian rubble around coral
in wait for attachment in a fashion that might resemble rocks
around a campfire. This method is also used to contain a vigorous
or overgrowing species of coral from encroachment on neighboring
cnidarians. Millepora, encrusting and stoloniferous
corals like Star polyps, zoanthids like yellow polyps/anemones,
and Xeniids are just some of the many fast growing cnidarians
sometimes in need of being kept at bay, so to speak, by just
such a rubble "firewall". Even a cursory glance
on the Internet will reveal these and many other useful methods
of containment for fragmented and unsecured corals.
The goal of containment is
to reduce disturbances from water flow or macro-organisms
pending natural attachment while affording maximum and hopefully
unfiltered illumination in the process. Such methods can be
highly recommended for commercial and small-scale operations
alike, as materials for containment are generally inexpensive
or reusable and have little impact on operational expenses.
Some of the most dynamic effects
in reef gardening can be made with containment techniques.
PVC collars and clear tubes can be used, for example, to trap
coral fragments on the rockscape in precarious and dramatic
locations. One of the most popular exploitations of this technique
is to place various colored zoantharians (colored button polyps
or mushroom anemones) in a wild array of colors in relative
close proximity. A veritable living rainbow of color. Likewise,
various corals may be settled on the facial/vertical edges
of great spanning arches or atop the overhang of a cave, for
example, all with the strategic placement of lift tubes and
collars as methods of containment. Short segments of pipe
can effectively restrict lateral movement in areas of low
to moderate current and situated on relatively level planes.
Longer sections of clear pipe/tube are cut at similar angles
to match the targeted rock (or glass) surfaces and will be
necessary for vertical surfaces and planes. In such cases,
with a propped length of clear lift tube (say, 1" or
larger) projecting from the surface of the water (perhaps
resting on the edge of the aquarium), the coral fragment is
dropped into the tube to fall guided with gravity to the targeted
location in the aquarium below. Notches or holes may need
to be cut into the lower region of the tube to afford better
water circulation while still containing the fragment diffusively.
Please notice the picture of mushroom corallimorphs attractively
crowded on a sheer vertical rock face below that can be created
with such applications.
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A tremendous collection of corallimorphs in a mature
reef display at the National Aquarium in Baltimore.
This aquarium has been operating for over 13 years.
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Aesthetics aside, the practical
application of securing techniques by containment can simply
involve cups or jars. Plastic or glass vessels
may be partially filled with aggregate (crushed rock, coarse
sand, bio-rubble, etc.) to contain freshly fragmented divisions
of coral for settlement. This method is commonly employed
in organized coral propagation such as commercial farming
and large-scale local trade. In commercial coral farming,
coarse aragonite filled cups are packed onto suspended shelves
or tables in shallow, inexpensively lit, growout vessels.
Optimum light and moderate water flow will bathe the culturing
cups, and divisions can be systematically grown, graded and
cycled through them. Aggregate is replaced as necessary, since
occupying fragments export bits of substrate with natural
attachment and their sale out of the system.
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Natural settlement on coarse substrates like crushed
coral, aragonite or broken shell is commonly employed
in commercial operations as an inexpensive and successful
method for securing coral. Open rubble troughs and
species specific displays are preferable to cups,
netting, mesh, veil and the like that may be an impediment
to water flow and light for settling coral.
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One of the most popular forms
of containment in the commercial propagation of corals is
floral piks and pre-formed plugs with piloted
holes. The fabrication of plugs is somewhat time-consuming,
and more appropriate for aquarists seeking a natural looking
substrate for cultured fragments in local trade and small-scale
operations. Plugs are usually formed with a calcareous aggregate
of crushed coral, coral sand, aragonite, or shell mixed with
limestone/cement. Once cured, it is a fine method for attaching
coral, but labor intensive for commercial mariculture. Curing
for use in aquarium systems may require etching with a weak
acid or soaking the raw, cement product for some time in freshwater
especially if many newly formed plugs are to be added to a
system at once. For-profit endeavors often use a favorite
of mine, floral piks, which are short plastic tubes with a
rubber cap commonly used to hold fresh cut flower stems and
corsages. They can often be inexpensively obtained from a
local florist or wholesale sources. Please notice the photographs
below depicting new, encrusted dry and encrusted living floral
piks. The piks are usually green and quite conspicuous, which
helps coral farmers clearly evidence the cultured nature of
their product for expeditious and lawful export of CITES regulated
animals abroad. The rubber caps are flexible and adjustable
to hold a wide range of fragment sizes. And, consumers should
have little concern about the aesthetics of this application
as healthy corals quickly and easily encrust the caps of the
floral pik bodies, when most of the artifact is usually hidden
in the rockscape anyway. The uniform and discreet size of
each floral pik also affords the coral farmer great control
over aggression in placement of specimens in growout.
Floral
piks are an ideal artificial tool for culture and shipping
SPS fragments, and can be ordered from a local florist
for mere pennies. They are inexpensive, adaptable and
serve commercial interests admirably in evidence of
the conspicuous aquacultured nature of the product when
shipping controlled species abroad. Center image
depicts the growth of an immature Pocillopora
fragment fully down the body of the pik.
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In a most elementary application,
simple holes may be drilled in the rocks with an electric
drill and a masonry bit, or natural crevices can be
utilized just the same. Corals are simply inserted or wedged
into the recess. Obviously, there is little production cost
to utilize this method of containment. Unfortunately, it is
the least reliable method when unassisted as fragments can
be blown away by currents or moved by creatures. Piloted holes
are more useful for holding corals cultured in solidly encrusted
narrow tubes or floral picks. However, more than a few years
ago, Dick Perrin of Tropicorium, demonstrated an interesting
and useful modification of this technique. Mr. Perrin gave
a great demonstration on a gentle technique for attaching
gorgonians where he inserted fragmented divisions of gorgonians
into holes in calcareous rock that were slightly bigger than
the diameter of the animal's base. Incidentally, the base
of the gorgonian was prepared by stripping away ¼-1/2
inch of tissue to expose the woody gorgonin stem, thereby
reducing the chance of infection from the forcibly stifled
living tissue. Divisions were then held in place with a tapered
wedge of firm Styrofoam inserted with the base of the gorgonian
into the rock. For coral farmers shipping and receiving live
aquatic animals, Styrofoam is in abundance and broken pieces
may be recycled, at least in a small quantity, in this manner.
There are indeed many other effective ways of naturally containing
fragmented divisions of coral in wait for natural attachment.
Impaling Coral Fragments for Attachment
Impaling corals is a remarkably
simple, if not crude, method of securing both hard and soft
coral. In essence, only the living tissue of soft corals is
actually impaled. LPS corals simply have their skeletons drilled
for pegs (or stitches), but their living tissue is usually
untouched. Thin, solid, acrylic rod is fitted in holes drilled
through or up into (depending on the desired orientation of
the subject) a scleractinian "skeleton" (corallum)
for attachment to a reef structure. Pegs do not need to be
large or conspicuous, as this methodology is sturdy and rigid
for securing stony corals. Exposed facets of the hardware
will soon be covered with benthic organisms such as sponge
or coralline algae. Pegs may be glued in place or merely set
in a snug fit. SPS corals are not usually impaled in any manner,
as any of several other methods of securing them will invariably
suit a given specimen better. Almost any soft coral or zoantharian
that can be successfully fragmented can be impaled safely.
Impaling is often conducted
with a plastic toothpick or cocktail pick. Other spears
are safe and appropriate if made of food grade plastics. Wooden
and stainless steel picks have been used by aquarists but
really do not need mention or recommendation when plastic
picks are so commonly available. Picks with a handle or flared
end will help to prevent a fragment from sliding or expanding
off of the toothpick. Aquarists, no doubt, can use their imagination
for alternatives. Success is often hampered by water flow
or movement of picks within shallow holes or crevices. As
an improvement on this concept, the plastic pick can pass
equally through the stalk of a soft coral (extending out from
either side) to permit gluing or (rubber) banding of the ends
of the pick to rubble to lend weight and absolutely contain
the impaled coral. Impaling is a relatively harmless method
of securing fragments of coral, since only a small and single
puncture is imposed on the division. Many notable aquarists
such as Daniel Knop have described this technique of attachment
for propagated corals for aquarists. Impaling, although not
especially graceful or delicate, is one of the few reliably
successful methods for attaching heavily mucous soft corals
when faster and less conspicuous methods of attachment are
not feasible. The tiny spiculed, "slimy" Sinularia
species (like Green or Yellow Finger corals), Klyxum
and Cladiella "Colt" corals, Xeniids and
even corallimorphs respond well to this technique. After a
few days when the fragment seems to be adequately attached,
the pick can be removed by first spinning it in place (rolling
the pick between the fingers) to ensure that withdrawal will
not pull the newly attached fragment off of the substrate
if stuck to the pick. Impaling "leathery" soft corals,
including Sarcophyton and Sinularia species,
can be done as easily and with even greater survivability.
Neptheids respond only moderately well to this technique.
Impaling is not convenient for most gorgonians and stoloniferous
corals. Zoanthids respond very poorly to this technique and
may exude damaging amounts of noxious compounds in defense
of the molestation. Research on the viability and tolerance
of corals suffering such imposed techniques of propagation
and settlement is necessary for good aquarium science; please
record and share your results with other aquarists.
Natural Attachment
Natural attachment
is defined here as the encouragement of unassisted, or at
least unimposed, attachment of coral tissue to natural or
artificial substrates. Substrates for securing corals naturally
are about as varied as one can imagine. Some popular surfaces
include live rock, crushed live rock, bio-rubble, crushed
coral, various grades of aragonite sand, snail and clamshells,
and ceramic tile. Parent corals with little or no tolerance
to handling or propagation can be established instead in a
dedicated rubble trough and encouraged to grow out to maturity.
In time, they will begin branchlet dropping or may permit
limited asexual fragmentation. Successful divisions can then
simply be dropped to the floor of the rubble trough for settlement
and growout. In my opinion, it is one of the very best methods
of attaching coral fragments for coral farmers who can afford
the time and space to conduct the activity in dedicated culturing
vessels.
One of the very best materials
for securing divisions in coral propagation by natural attachment
is "bio-rubble". Bio-rubble is the inevitable by-product
of live rock imported and shipped domestically. Very small
pieces of this scleractinian product occur in small to significant
quantities in shipments of live rock that move into and about
the country every day. It is not uncommon for up to 10 percent
of a shipment of live rock to be crushed or broken into small
or tiny pieces that are useless for the collected purpose
of rockscaping. Since this bio-rubble is too small to use
for decorating, but too large for use as filtration media
(it traps detritus excessively without effective pre-filtration),
it is usually discarded by importers and other resellers of
live rock. Aquarists are encouraged to court local resellers
of live rock products for such rubble that may be used in
coral propagation for local trade. In many cases, a kind retailer
may be inclined to save the fragments of live rock from weekly
shipments for local coral farmers to use in exchange for considerations
on supplied, propagated coral. In any case, bio-rubble should
be available inexpensively, as it has little or no other market
value. The caveat for this practice is directed towards international
shippers of propagated coral. To send propagated coral out
of the country soon or in the future, it may be necessary
to culture reef invertebrates on conspicuously artificial
substrates instead to demonstrate the captive bred nature
of the product in the face of increasing legislation on the
trade of wild harvested and CITES protected stony corals.
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Bio-rubble filled growout containers in Dick Perrin's
coral farming wonderland, Tropicorium
Romulus,
MI.
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Having described some of the
most popular methods for securing propagated corals, let me
offer some wisdom in a general overview of the activity:
Know Your Invertebrate's
Tolerances
There can be a tremendous
range of tolerance and sensitivity to various aspects of coral
propagation regarding handling, cutting and attaching corals
even among species within the same genus. Research a candidate
thoroughly when information is possible about such techniques,
and report your findings when such information is not available.
Please give your knowledge as freely as you take it.
Reduce Handling Time to
the Barest Minimum
Avoid touching live coral
tissue whenever possible and wear a clean glove when it is
not. Increased handling time decreases survivability by mitigating
deleterious factors (increased mucus production, creating
abrasions or wounds that invite infection, etc.)
Do Not Move Secured Divisions
in Growout Frequently
Frequent movement of new/unsettled
divisions, especially on a vertical scale, dramatically increases
the risk of mortality. Put a fragment in a good and secure
place for growout the first time and leave it alone! Movement
of a young and stressed division that forces the expenditure
of limited and strained sources of energy to compensate for
changes in lighting and other life supporting parameters is
dangerous and irresponsible.
Never Place a Fragmented
Division of Coral in Brighter Illumination Than the Parent
Asexually fragmented divisions
demonstrate higher survivability if attached to a substrate
for growout at a level of illumination that is the same or
slightly lower than the donor. Lateral moves within the system
are generally safe. Such propagation is especially easy to
accomplish in dedicated systems for coral farming with deliberate
shelves or static water depths for the terrain (like a monospecific
rubble trough for parents and cultured divisions).
Minimize Physical and Chemical
Aggression in Growout
Most propagated divisions
of coral will attach and growout more successfully without
competition from neighboring coral/cnidarians. Farming that
must be done in mixed species displays can reduce the impact
of chemical aggression by propagating only one or just a couple
of species at a time. Otherwise, numerous specimens/species
of freshly cut corals will dramatically increase the "toxic
soup" from the inevitable duress. Ideally, farming corals
is to be done in monospecific displays where specimens cannot
touch each other. Aggressive protein skimming, chemical filtration
and water exchanges are necessary and critical to reduce complications,
not the least of which will be from allelopathy.
Fragments Permitted to
Attach Naturally Should Be Placed "Face" Down
Simple divisions of corals
attach best if healthy tissue is placed downward (believe
it or not) in contact with the intended substrate for settlement.
Damaged tissue and exposed skeleton should be oriented upward
to receive optimum light and current for expeditious healing.
The colony will soon grow to a natural shape with available
light and water flow.
Parting Thoughts
When selecting materials for
use in coral farming, please be conscientious that you should
be utilizing items with the lowest possible environmental
impact. When using plastics, try to employ materials in techniques
that are re-usable (releasable cable ties, slip knots on constrictive
ties, even asking your friends/customers to send back floral
picks, etc. that will not be recycled). This is especially
important for larger farming operations with consideration
for the burden already placed on limited resources, when recycling
will obviously contribute to profits on the bottom line. Live
rock and dry ancient reef rock ("tuffa"/carbonate
rock from land) hardly qualify as low impact materials.
Indeed, limestone/aragonite for making cement plugs and the
like are also products of a defined, limited and non-renewable
resource: ancient reef deposits. Whenever possible, utilize
inevitable byproducts like bio-rubble from live rock shipments
or recyclable plastics.
There are many ways, of course,
to practice responsible aquariology. People must necessarily
exploit natural resources, but it can be done responsibly
and with consideration and great empathy. I present this as
a challenge especially for aquarists and other consumers of
coral reef aquarium products who intend to fill their displays
with mostly or only captive propagated specimens. Indeed,
low impact systems are becoming common, and I suspect that
zero-impact reef displays will be an everyday reality in the
near future. The progress that aquarists have made in just
a matter of years
barely decades, from the perception
of live corals from being mysterious and impossible to sustain
in captivity to a point now in time where their overgrowth
has become an issue in husbandry is testimony to the passion
and dedication of reef enthusiasts. I wish the best of luck
to you in all of your honest endeavors.
With kind regards,
Anthony Calfo
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