If we take a look at toadstool leather corals of the
genus Sarcophyton we should notice that the animals could be divided
and distinct parts. There is the central column that anchors the coral
to the substrate, there is the “crown” which resembles
the cap of a mushroom or toadstool, and the polyps that arise from
itself and stretch into the water column. The latter are more correctly
termed autozooids in this genus and most species of soft coral have
quite prominent ones. Many soft corals from the Family Alcyoniidae,
Sarcophyton and Lobophyton are but two species, possess another distinct
type of polyp. Close examination of the surface of the coral reveals
a grainy texture. This is not some unique characteristic of the coenochyme but actually a specialised type of polyp called a siphonozooid that
is very small and does not usually possess tentacles. The siphonozooids
are much more abundant than the larger autozooids; the large white
The role of the siphonozooids is to facilitate the movement of water
into and out of the colony itself. They can also contain photosynthetic
Easy as that? Of course not! For reasons unknown many specimens of
cathedral coral such as the species illustrated here seem extremely
reluctant to extend the larger white autozooids. Sometimes it is almost
impossible to detect the presence of these polyps but otherwise and
almost more frustrating is that they are present as small circular
bumps on the surface of the corals. It is not uncommon for a specimen
to have such an abundance of white autozooid polyps on display in a
dealer’s aquarium that the first visiting aquarist to witness
such stunning beauty is compelled to make a purchase only for these
large polyps to never be seen again. This understandably results in
an aggrieved aquarist who might become apoplectic when upon returning
the coral to the dealers system the beautiful white polyps reappear
within twenty minutes or so! It is difficult to ascertain why this
apparent reluctance of the coral to extend its autozooids occurs-it
certainly does not seem to be as a result of any nipping by resident
fish. Fossa and Nilsen suggest that this may be due to the presence
of hard corals in the aquarium but we suggest that this is only part
of the story.
The presence of the two forms of polyp in cathedral corals is the
easiest way to separate this so called dimorphic leather coral from
soft corals classified within different families but there are other
clues as to its true identity that can help separate the cathedral
from other closely related species. It is never found with a long “stalk” like
Sarcophyton spp. soft corals and is often encrusting, sometimes forming
huge colonies. Alternative common names for this species include the
devil’s finger or finger leather coral.
Selection of a good specimen is of the utmost importance for the cathedral
coral. Individual colonies with bright yellow or white patches anywhere
on the body should be avoided. It is not uncommon to find the folded
margins of this coral gradually dissolving as it succumbs to bacterial
infections. If you can located a specimen in which the large autozooids
are extended then that’s great but if not then don’t worry
too much as the coral may be located in an aquarium that does not suit
such polyp expansion. Once transferred to your aquarium and if conditions
are conducive then autozooid polyp expansion will certainly occur.
You should be aware that autozooid polyp colouration can vary from
brilliant white to brown-beige via yellow and so witnessing the autozooids
expanded does have definite advantages for the aesthetes amongst you.
Despite the obvious affinities of the leather corals it should be
noted that not all species are easy to maintain. Lobophytum cathedral
corals though not necessarily difficult can be quite particular about
where they like to be placed and so the aquarist should offer strong
lighting and strong flow for the best results. The specimen illustrated
here was located on the bottom of a 60cm deep aquarium that had twin
150W 13000K metal halides over the top. An aquarium using T5 lighting
might need to have this coral species in a very prominent high position.
In short, it is difficult to give this species too much light and very
easy to give it too little.
With regard to flow this species shares the requirement of all leather
corals for a minimum flow rate that is capable of lifting the mucus
film that can form on them as a result of their excretion. Should flow
be low enough for detritus to settle upon the surface of the coral
then the latter may show an adverse reaction. It is difficult to provide
too much flow for cathedral corals. Care should be taken with the location
of this species particularly if it is “upstream” of stony
corals. Many soft corals are known to use highly toxic terpenoids as
anti-predator and anti-colonisation defences and the fact that the
coral can constantly produce these can mean that if the stony coral
is not killed by this chemical onslaught then its growth at least could
be seriously compromised.
Although the captive propagation of Lobophytum soft corals is nowhere
near impossible it does carry more risks to the parent colony that
for other leather corals like Sinularia or Sarcophyton. As we hinted
at earlier when describing the selection of good specimens this species
seems to be susceptible to bacterial infections particularly when damaged
or when placed in unsuitable conditions. Any signs of yellow or white
necrotic tissue should be addressed immediately. Often relocating the
cuttings into areas of high flow or subjecting the parent colony to
more than usual flow can help but the propagator should consider iodine
dips if the condition does not clear up.
We are sure that there are many points that we have neglected to mention
about this attractive species of soft coral and yet we hope that if
you weren’t aware of it already then you are armed with sufficient
knowledge to feel confident to have a go at keeping a specimen.
References and Acknowledgements:
We would like to thank Robert Sutton for the use of his image of Lobophytum
Fossa and Nilsen. The Modern Coral Reef Aquarium Dahne Verlag.
Baench. Marine Atlas Volume 2.
Delbeek and Sprung . The Reef Aquarium Volume 1
Sprung: Corals. A Quick reference Guide.
Ecology: Vol. 58, No. 6, pp. 1218–1236.
Feeding and Growth Rates of Polinices Duplicatus Preying on Mya arenaria
at Barnstable Harbor, Massachusetts
Kingsley-Smith, P. R., Richardson, C.A. & Seed, R. 2003.
Stereotypic and size-selective predation in Polinices pulchellus (Gastropoda:
Naticidae) Risso 1826. Journal of Experimental Marine Biology and Ecology,
Kingsley-Smith, P. R., Richardson, C. A. & Seed, R. (2005). Growth
and development of the veliger larvae and juveniles of Polinices pulchellus
(Gastropoda: Naticidae). Journal of the Marine Biological Association
of the UK. Vol. 85, pp. 171-174.
Kingsley-Smith, P. R., Richardson, C. A. and Seed, R. (2003). Seasonal
and size-related egg collar production by Polinices pulchellus (Gastropoda:
Naticidae) Risso 1826. Journal of Experimental Marine Biology and Ecology.
Vol. 295, pp. 191-206.
Kingsley-Smith, P. (2003). Polinices pulchellus: The James Dean of
gastropods: Living fast, dying young. Journal of Shellfish Research.
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