Sea Mat: An Ocean Of Color For The Aquarium
by Blane Perun
To some extent, the physical characteristics of the colony are influenced by it’s habitat of origin. Two identical colonies could appear somewhat different, just like we see in other corals. Shorter, more compact specimens with smaller mouths for the most part come from high current areas. The specimens with more
elongated bodies, larger mouths, and longer tentacles more likely come from low current areas. Interestingly, these species occur in nature in a myriad of conditions from one extreme to another. Zoanthus colonies have been observed from reef crest (taking blows from the crashing waves) to tidal areas (being exposed to air for hours during low tide). In fact, it’s the durability of the species that make it such a good choice for the aquarium. These polyps tolerate a wide range of conditions and will flourish in nearly any aquaria.
smaller polyps and reproduce by forming buds from the base of the mated
tissue. This species, unlike some of the others in the family, does not
incorporate sediment into its base. The oral disk is in the center of
tightly-packed tentacles, and appears in nature in a variety of colors and
much like the Palythoa in size but with the exception that the polyps are not
connected to one mass of tissue. Some seem to have less more pointed
tentacles in some cases they even alternate up
and down (Sprung 2001)
Selecting Stock & finding a gem
If you look closely, you can see that the light green mouth is surrounded by a zone of high contrast that looks to be a deep purple. The first ring on the oral disk is light orange, which almost appears to graduate to a darker orange. The disk’s final ring is in purple, repeating the contrast zone around the mouth. The tentacles begin in a light, muted green- the same color as the mouth, and finish in an incredible iridescent green. Such a display of color I find truly amazing. I found this colony locally for $25 dollars. It had about 20 polyps, but not near the impressive display that it has evolved to in my system. In about a year, I have traded no less than 5 fragmented plugs of this color morph for many more brilliant colors to expand my collection. You can see more than 25 color morphs that I have collected on my web site, under “Captive Propagated Species” in the “Coral Farm” section.
Sometimes, it is just as enjoyable finding a few polyps accidentally (that have come in as hitchhikers on another piece of coral picked up through mail order or from a local fish store) as it is coloring up a specimen. Zoanthus often come in this way because of the encroaching nature of colonies. The L.F.S usually does not separate them and grow them out they mostly sell the specimen as it came in. One of my greatest finds was on a piece of “Wood Sponge” or Placospongia. I actually saw a few polyps on the underside when I was purchasing the specimen, but they were closed and I had no idea what to expect.
Aquascaping a reef system presents many challenges to both
the novice and advanced hobbyist. Some aspects, such as rock structure, are
mechanical in nature, and can be solved though patience
use of zip ties. Others can be a bit
more daunting. Aesthetics- for example, specifically balancing color and
texture, can seem impossible at times. I have always strived to keep a bit
of everything in my display systems, and even with the most diverse
collection, one can find oneself with a display leaning towards specific
shades and tones. Most of my systems had been predominantly SPS, with some
various LPS and exotic leathers. For the most part, my stony corals were
Blue, Pink, Yellow, Purple, or
Green. Green and Blue seemed abundant, and colors like Yellow had been
limited to mostly Porites
and Sarcophyton. I had a bit or difficulty pulling the eye away from such a
dominant focal point, partly because the yellow color was scarce, and
secondly, the Porities were large colonies
compared to the other SPS. Nothing enhanced the display more than my dive
into Zoanthus. With such a wide variety of color, I was able to balance out
the look and feel of the tanks
and Palythoa both contain very toxic chemicals,
that are dangerous to both reef inhabitants and humans. The most
well known is Palytoxin, which has been
documented as one of the most poisonous marine toxins known (Mereish
et al, 1991). Palytoxin can affect the heart, muscles, and nerves leaving its
victim in paralysis, and possibly death. Because of the toxin, you should
never handle Zoanthus or Palythoa with open wounds, nor should you touch
your mouth or eyes after handling the species.
(Editors’ note: We recommend the use of disposable latex gloves)
When propagating either of the species, it is critical to remember
that the slightest rub of an itchy eye, or even a small cut from a hang
nail, might be enough to land you in the hospital. In the aquarium, some
rapid growing Zoanthus colonies can be aggressive to stony and soft corals,
but in general, they are very peaceful, and you can slow the growth rate by
the controlling the overall nutrient load of your tank.
In my years of observation of Zoanthus,
I have seen some grow at tremendous rates while others were lucky to add on
a few polyps per year. With the same size stock and oral disc you would
assume they could have come from relatively similar conditions, and should
respond in nearly the same manner. With Zoanthus,
this could not be further from the truth, in my experience. Many of the
color morphs looked identical but grew at totally different rates under the
One example is a pink color morph specimen that is by far the most aggressive and rapidly-growing one I have worked with to date. I have witnessed the colony quickly surround a Blue Acropora abrolhensis and slowly kill off the tissue and begin encrusting on its base.
The second most aggressive morph that I keep is what I call “Actinic Yellow”
. You can see in
the photo that they are growing right along side of a piece of Heliopora. If
you familiar with the coral, it’s a quick growing mass that can cover most
everything in the aquarium. The Zoanthus polyps however, kept the colony of
Heliopora’s growth in check along the side where the two meet. When the
mouths would close at various times, you could actually see a series of half
circles in the Heliopora that almost appear to
be worn down from the polyps.
Over the years, I have certainly experimented with a variety of foods. With pipettes and turkey basters, I would gently shoot a small cloud of over the colonies. While some tentacles would appear to grasp the food particles and wind inward toward the mouth, it was never perfectly clear whether is was a reaction to the stream, or an actual feeding response. In the case of the large- polyped Palythoa and Protopalythoa, feeding is much more obvious.
Soft shrimp pellets, for example, are taken readily, and you
can see the tentacles grasping the food bits and closing in around the mouth
and oral disk in just a few minutes. Upon completion of my dedicated system,
I plan to study the direct feeding and growth rates of Palythoa, comparing
two identical colonies- one being fed directly, and one not.
, I have witnessed slow to moderate growth at best, in comparison to other
polyps. Zoanthus, on the other hand, will
and reproduce quickly with some intervention. While I’m yet to
find if direct feeding can make an impact on some of the color morphs I have
more trouble growing, I can say with confidence that keeping the nutrient
load high in the aquarium expedites reproduction. From my observations in
the case of most polpys, heavy feeding of fish
seems to create a more conducive environment than any attempt at direct
attempts thus far.
While larvae from sexual reproduction from Zoanthus and Protopalythoa has
been found in plankton (Sprung 1997),
have never witnessed it in my tank, nor am I holding my breath. Asexual
reproduction does take place however, and basically has been the catalyst of
growth in all of the species I propagate. With regards to the Palythoa and
Protopalythoa small buds appear at the base of the mature polyps. Asexual
reproduction in Zoanthus usually takes place as small polyps grow from the
fleshy tissue know as “Coenenchyme”. In some
as those where the colony seems to have nowhere to expand, the new polyps grow
more dense throughout the tissue mass. In cases where the Zoanthus plainly
has room to spread, the maturation process tends to take place along the
perimeter. Keeping this in mind: You have the
opportunity to control the expansion of the polyps by physical means in the
In cases where I added a morph to a specific area for color,
which I knew grew rapidly,
I would be careful to how I mounted
the coral in the display system. It is best to keep the rock isolated from
other rocks, so that the polyps stay contained. I would often glue rocks in
place with underwater epoxy that would appear to be touching the rest of the
rock structure, but in fact were a few inches away.
The reproductive properties of the Zoanthus make it a perfect candidate for manual propagation. I have found that the Sea Mat tissue tends to grow in either a thick, dense fashion, or spreads out more like spaghetti. In the case of the second growth pattern, it’s quite possible to peel up a section near the outskirts of the colony and gently peel the Zoanthus off the rock. You can cut a few strips into one inch sections or so, and mount them to plugs via plastic toothpick, or a gently bound zip tie. While I am an advocate of using small amounts of adhesive, I have experienced some polyps to react adversely to these products. I remember applying just a small dab on a blue morph, which seemed to decay the tissue over a period of days. The colony eventually disintegrated, either directly from the adhesive “burn”, or from a secondary infection brought on by the decaying tissue. While this might not be the rule, it is a possibility, so I now pierce the fragments with plastic toothpicks. Attaching to the new substrate will take place in a very short time.
A second method I utilize is actually chiseling off bits off the colony, by chipping away at the underlying rock, or just splitting the rock and cutting the tissue with a sharp blade. In cases where it is not possible to break the rock, you can cut or chip away with a small screwdriver or Dremel about ¼ inch below the tissue. You will end up with some small pieces of flat rock encrusted in polyps which you can then glue to a reef plug.
The above photo shows a two month-or-so-old propagation that had originally
been adhered to a plug via superglue gel. The colony soon grew over and
around the plug. The first time I needed a
to trade or sell, I would cut off the original adhered piece, leaving the
overgrowth. The plug now is a perfect candidate to be cut down into a few
For more information on captive-raised coral and propagation,
feel free to check out my web site
All Photos Copyright 2002 Blane Perun Thesea.