Setting Up a Reef Tank
Part 7
by Marty Ziegler
First published in Gravel Gossip, Diamond State Aquarium Society
Aquarticles
THE SOFT CORALS - Leather corals
So far, we have explored the mushroom anemones corallimorpharia and the button
polyps zoanthids. Now we will look at another coral, the leathers, that carry the same
traits of being readily available with plenty of species to choose from, inexpensive, very
hardy, and an easy coral for the beginning aquarist.
The leather corals from the genus Sarcophyton, from the Order Alcyonacea,
are soft corals that are fast growing and appear as large mushrooms or toadstools. From
the top of the head, or capitulum, a large number of polyps emerge. There are
actually two types of polyps found on the leathers. Autozooids are tubular with tentacles
while siphonozooids appear like freckles. Leathers are usually attached at the base to a
rock or piece of dead coral. The skin of the leathers is soft, although tough, to the
touch. Trying to pick up a leather will cause it to retract the polyps and will shrink up,
feeling like a wet piece of leather, albeit a bit more slimy. They are found in various
shades of brown, green, red, and yellow.
These corals do contain symbiotic algae, zooanthellae, so there is no
requirement to be manually fed. They do require moderate lighting for the zooanthellae
to provide the nutrition the leather corals need. Some like more intense lighting than
others, which can be determined if the polyps stay retracted for more than a few days at a
time. If this occurs, move the leather to a different location in your tank. Be careful,
metal halides can 'burn' some leathers that are too close to the surface.
As for water current, the leathers do need a moderate current flow. This is especially
important to help the leather coral to remove detritus and algae, which may have deposited
on top of the head. The leather forms a mucus coating, which it sheds from the top of the
head, from time to time. Some leather corals do this quite often, initially begun by the
polyps staying retracted for a couple of days, with a shiny, waxy coating appearing on the
top of the head. This then starts to lift off, with the water current helping to clear it
away from the leather. Be forewarned that this mucus coating contains terpenoids that are
toxic to other corals, so you should try to siphon it off as soon as it starts lifting off
the leather. I have been fortunate that this has not caused a problem in my crowded reef
tank, probably due to the strong filtration, good protein skimming, and strong water
currents maintained in the tank, breaking up the mucus rapidly before it can settle on any
other corals.
The leathers are considered low in aggressiveness, although due to their chemical
defense system, they can inhibit the growth of other corals within close proximity. The
leathers are more prone to be stung by other corals. If the leather is keeping its polyps
retracted for more than a couple of days, this could be from being too close to another
coral. The bottom line is, if your leather's polyps are retracted for longer then a few
days, there is something wrong that needs to be addressed, whether it be lighting,
location, aggression, or water flow.
As I said earlier, with the zooanthellae providing nutrition to the leather
coral, it is not necessary to manually feed it. The leathers do benefit from regular
additions of iodine, calcium, and strontium, which ensure rapid growth. I currently use a
calcium reactor, which provides these additives continuously; with the only additive I add
manually being iodine once a week.
Reproduction in the leathers can occur from budding at the base. I have had a leather
move from one location to a higher spot, leaving behind a piece of itself. This piece soon
developed a few polyps and then formed a head, later developing into another toadstool
leather. Slicing a portion of the head, like a piece of pie, and attaching to a rock with
monofilament line or a rubberband can also be used to propagate leather corals.
Another species of leather coral is the genus Lobophytum, mainly an encrusting
species, which includes the cabbage, lettuce, and finger leather corals. These tend to
group together, forming a patch of leathers on one or more rocks. Their care is the same
as the genus Sarcophyton.
I hope you found this helpful in your search for easy-to-keep corals. Being a hardy,
fast growing, inexpensive, easy to maintain soft coral, the leather corals are ideal for
both the beginner and advanced reef aquarist.
Until next time, happy reefkeeping!
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